Skip to main content
 Previous Next
  • Zoom In (+)
  • Zoom Out (-)
  • Rotate CW (r)
  • Rotate CCW (R)
  • Overview (h)
Part II: Marine and Freshwater Zoology: Encyclopedia Arctica 3: Zoology (Excluding Birds)
Stefansson, Vilhjalmur, 1879-1962

Part II: Marine and Freshwater Zoology

Marine

Faunistic Effects of Climatic Change in the North

EA-Zoology
( Max M. J. Dunbar)

FAUNISTIC EFFECTS OF CLIMATIC CHANGE IN THE NORTH

CONTENTS
Page
Introduction 1
Fauna of the Land 6
Marine Fauna 10
Bibliography 17

EA-Zoology
(Max J. Dunbar)

FAUNISTIC EFFECTS OF CLIMATIC CHANGE IN THE NORTH
Introduction
During the past thirty or more years there have been changes in the
climate of the arctic and subarctic regions, manifested in a progressive
warming in both the atmosphere and the hydrosphere. Clearly the atmos–
pheric and marine climates are interrelated, but the mechanism of the
relation, and the causal paths involved, are at present uncertain. These
effects have altered the distribution of plants and animals, resulting in
a general northward extension of distribution, which is much more immediately
apparent in the sea than in terrestrial environments.
The whole matter of recent climatic change has been reviewed by
Ahlmann (2) in a paper in which the climatological, glaciological, oceano–
graphic, and biological evidence for the recent warming is brought together,
and some years previous to Ahlmann’s paper, Jensen (15) made an extensive
review of the pattern of change, particularly as it affected West Greenland.
Both papers contain extensive bibliographic lists to which the reader is
referred. The increase in atmospheric temperatures has affected the whole
of the Northern Hemisphere, in all probability, but information from certain
parts of the North is lacking. Ahlmann has emphasized the urgency of the need
for the study of this change in greater detail, and has brought home the fact

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

that “here is something happening” which affects all of us, both at present
and in the immediate future.
The underlying cause of the present warming effect, and indeed of longer–
term variations and fluctuations in climate, is not certain, but as early as
1916, Helland-Hansen and Nansen suggested that the terrestrial climatic
variations must ultimately becaused by variations in solar radiation; that
increased solar radiation set up increased atmospheric movement, and thus the
faster transmission of energy from the tropics to the poles. That climatic
variation is normal is obvious from a consideration of the geologic past of
the earth, and Ahlmann (2) has summarized the effects of recent (post glacial)
variations in northwest Europe, Iceland, and Greenland, areas in which it is
clear that the human economy within historic times has been greatly dependent
upon climatic conditions.
In the atmospheric climate, the most spectacular changes in recent
decades have perhaps taken place in Spitsbergen, where there has been an
increase of no less than 9°C. in the mean winter temperature between the
period 1911-15 and 1931-35, the actual figures being −17.6°C. for the earlier
period and −8.6°C. for the later. In Greenland, the winter temperatures at
Jakobshavn during the period 1923-32 were more than 5°C. warmer than those
registered fifty years before, and there has been a steady rise since 1932.
Positive deviations from the former mean temperature, of from 2 to 4 degrees,
are the rule at all Greenland stations. In Canada, information on atmospheric
temperatures has recently been brought together by Hare (1950) in an exhaustive
study of the climate of the Canadian eastern Arctic and Subarctic. At Moose
Factory, Southwest Point (Anticosti Island), and St. John’s, Newfoundland,
the coldest period is shown to have been about the year 1915, since which

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

time there has been a slight rise of one or two degrees Fahrenheit in both
winters and summers. It was warmer in 1870-1910 than between 1915-20.
Such information as is available from northern stations in the eastern
arctic of Canada (Craig Harbour, Pond Inlet) also shown an increasing
temperature. The warming effect is, however, not so marked in Canada as in
Greenland and (especially) Spitsbergen; in fact, the effect is to some extent
related to the maritime nature of the climate. In the U.S.S.R., (Rubenstein,
quoted from Ahlmann 1949) (2), “it appears that an increase in winter tempera–
tures began about the latter part of the nineteenth century, and that it was
especially marked at such northern stations as Kola, Archangel and Leningrad,
while no increase was noticeable, for example, at Kiev.”
Glaciers all over the world are now receding, for example, a with
perhaps a few exceptions, and at varying rates. Recession appears to be
slow in Greenland, but in southern Alaska, Iceland, and Norway the decrease
in glacier size is impressive.
The pattern is similar in the marine climate, that is to say in the
temperature of sea water, at least in the North Atlantic and associated seas.
In the North Pacific arctic and subarctic area, the picture is uncertain due
to the lack of extended records with which to compare present observations,
but there is evidence of an increase in temperatures off the southern
California coast in recent decades (14), and in the coastal waters of British
Columbia (26). The marine change is perhaps most marked in West Greenland,
where the water has been growing warmer since about 1917, apparently owing to
a strengthening of the Irminger Current component in the West Greenland
Current (Jensen 1939, Kiilerich 1943, Dunbar 1946 and 1951). The Gulf
Stream itself has increased in temperature about half a degree centigrade,

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

at its origin in the Straits of Florida. The southern limit of ice in
the Greenland Sea (east of Greenland) retreated some 200 to 300 kilometers
between the years 1928 and 1936, and the thickness of the ice in the Polar
Sea decreased “from an average of 365 cm. during the Hansen Fram expedition
of 1893-96 to 218 cm. during the drift of the Russian ice-breaker Sedov in
1937-40” (2). In the Norwegian Sea, there appears to have been an increase
in both the volume and the temperature of the Atlantic water flowing northward,
of 2°C., compared with conditions at the beginning of the present century, and
Ahlmann (2) quotes Russian work on routine hydrographic sections along the
Kola meridian (33 1/2°E.), which showed an increase of the order of 2°C. in
the temperature at 200 meters between 1900 and 1921; the earming has been
continuing since 1921. A rise in temperature of the same extent has been
demonstrated in Spitsbergen waters, and the shipping season in West Spitsbergen
has been more than doubled since 1900. It appears, also, that the ice condition [: ]
along the Siberian shelf have been easing during the past decades.
In the Canadian eastern arctic, there is a lack of past records. It is
reasonable to suppose that the waters off southeast Baffin Island, in Hudson
Strait, and along the Labrador, have been influenced by the warming of the
West Greenland Current, most of which turns westward, south of the submarine
ridge between Greenland and Baffin Island, and takes part in the formation
of the Labrador Current. There is evidence of a biological nature (see below)
for the invasion of Atlantic water into Hudson Strait. The only physical
evidence is in the comparison between temperature and salinity measurements
made in Hudson Bay and Strait in 1930, by the Fisheries Expedition, and those
made in 1948 by the H.M.C.S. Haida. Working on these data, Bailey and Hachey
(5), and Dunbar (6) have shown that there must have been a significant increase
in both parameters between the years mentioned, which may perhaps be put down

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

to an increased influence of Atlantic water, as in West Greenland.
There is some evidence also to be gained from comparisons of the
open-water seasons for shipping in Hudson Strait and Ungava Bay in past
years and at present. According to all reports and the memory of Older
residents in the eastern arctic, the possible season for navigation into
and and out of Ungava Bay, some 20 to 30 years ago, was little more than
two to two-and-one-half months, or between the beginning of August and some
time in October. Today the open water season is much longer, extending from
the middle of July (earlier inside the bay itself) to late November at least,
probably well into December. Lucien Turner, who visited Fort Chimo in 1882-
84, records in his 1885 manuscript (27) that his ship was caught in the ice
at the beginning of August 1882, off the mouth of the George River; this
could hardly happen during the present years, when all the ice is out of
Ungava Bay by the middle of July.
Farther south in Canada, exceptionally high surface temperatures have
been recorded along the Atlantic coast in 1947 and 1949 (19), phenomena
which appear to be part of a general pattern of warming.
In this general process there have of course been relapses. In 1938
there was a very cold season in West Greenland, and the winter of 1948-49
was one of the coldest on record. In the Siberian waters, ice conditions
were bad in 1933, 1934, and 1936 (2), in the Kara Sea, and in 1942 they were
again bad, worse along the whole northern route than at any time in recent
years. There are similar variations in the ice conditions in the Canadian
eastern arctic. It has been suggested by the present writer (8) that there
has not been any significant increase in water temperatures in West Greenland
since about 1936, and that it is possible that the present warm period is

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

leveling off. It is much too early yet to form any firm opinion, or to
attain any sort of certainty on this point. Surface temperatures in Georgia
Strait, British Columbia, have been falling somewhat since 1940 (26).
Fauna of the Land
A warning should be sounded at the beginning of this section to the
effect that ( 1 ) recent northward extensions of distribution in terrestrial
fauna may not be caused by climatic change at all, at least in the obvious
and direct sense, and ( 2 ) if there is an important element of climatic
control, climatic change in the atmosphere may be long in inducing change
in distribution of animals; there may be a considerable time lag. Terrestrial
animals are not, for the most part, so delicately adjusted to environmental
temperature conditions as are aquatic animals.
The first possibility, that direct climatic control may not be involved,
follows from the fact that the areas that fall within the terms of reference
of this encyclopedia have generally been recently freed from a covering of
ice. Once the ice has retreated, the processes of soil formation will continue,
albeit at rates controlled by the climate, no matter whether the climate is
cooler or warmer. As soil formation proceeds, so will colonization by plants
and by animals. The rate of colonization (which is manifested by northward
extensions of distribution) will depend on climatic variation, but the mere
fact of northward extension does not necessarily imply a causal connection
with present climatic warming.
The fact that terrestrial animals, and especially the homotherms (birds
and mammals), are less delicately adjusted to temperature differences than
are aquatic animals, is demonstrated in an a priori manner by the failure
of the “life-zone” concept in classifying or formalizing the distribution

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

of life in North America. Founded upon temperature conditions alone,
Merriam’s original life zones are of only very general value, little more
than a useful descriptive convention. Nevertheless, it is clear that the
complex of factors which does control the distribution of animals is at some
point concerned with the atmospheric temperature aved average. Griscom (11),
in criticizing the life-zone system as applied to the distribution of birds,
seems to swing too far in the other direction, and to place too little impor–
tance upon temperature. He says, for instance: “In my lifetime various birds
have been steadily pushing northward and northeastward, and it follows, con–
sequently, that the present isothermal lines of their northernmost limits
are very much cooler than the isothermal lines that constituted limits
twenty-five years ago. In other words, it is obvious that temperature has
not limited the northward distribution of these birds in any way whatsoever.”
(11) p.160). The reclamation by birds of previously glaciated territory is
no doubt keeping pace with the reclamation by plants and other organisms,
but the influence of temperature upon the rate of that reclamation cannot
be ignored. With this preliminary warning of the limits of our present
knowledge, examples of recent northward extensions in the distributions of
organisms can be discussed.
The effect is of course not restricted to the arctic and subarctic
regions, but it is with these regions only that we are concerned here.
Griscom (10; 11) has mentioned several birds which have spread northward
in the United States recently, and Hubbs (14) has studied the question of
recent changes in the distribution of marine fish in the pacific coastal
waters, also of the United States.
Northward creep of vegetation has been observed in Iceland and in

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

Norway, Sweden, and Finland. “In the forests of northern Scandinavia the
economic benefits are of special importance. The trees are spreading
rapidly above their former limits, and the annual rings of both pine and
spruce show a quicker growth than they have for about two decades… Large,
formerly bare areas are now being [: ] invaded principally by birch and
willow; the timberline of the mountain birch is rising higher and higher.
Vegetation in general is becoming more luxuriant” (2). A similar creep
northward of the tree line has been observed in Alaska. A similar studies
of the tree line in northern Canada do not appear to have been published,
but the northward movement of certain mammals has been observed.
Rand (21) describes the coyote ( Canis latrans ) as the best example of
recent change in status and distribution. The coyote has “within the present
century…greatly extended its range northward and eastward and now occurs
as far north as the arctic ocean.” It is now known at Point Barrow, Alaska,
and in the Mackenzie Delta area. The red fox ( Vulpes fulva ) has been
gradually extending its range beyond the tree line and well into the edge
of the barren grounds. It is now recorded from southern Baffin Island (23)
and from Southampton Island (24). Whether this extension of range is
strictly referable to the climatic “amelioration” is uncertain; it might
conceivably be due to increased pressure from human populations farther
south.
The moose ( Alces americana ) was described by Anderson (4) as increasing
rapidly in numbers at that date, and also as extending its range northward,
in the Mackenzie district. Again in 1924, Anderson recorded similar events
in the moose population. The moose had formerly, according to Macfarland (20),
been scarce in this region. Rand (21) doubts whether this increase in numbers

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

and in range of the moose can be ascribed to climatic factors, and is
inclined instead to suppose that such fluctuations in the moose population
are due to a combination of other factors, such as parasites, disease, and
activities of man.
The activities of man in the cultivation of the land, farther south
than our present area, have long been known to affect the range of birds
and mammals. The movement northward of the white-tailed deer ( Odocoileus
virginianus borealis ) following the cutting of its native coniferous forests,
is such an example which should be mentioned here (3, p.7). Reduction in the
northern forests may also be related to the extensions of range in the coyote
and red fox, already mentioned, and in the apparent gradual colonization of
the barren lands by the wolverine (Gulo luscus).
Among birds, there are many examples of northward extension of breeding
ranges in the temperate parts of the Northern Hemisphere, including Iceland,
but evidence of such extension in the Arctic seems to be scarce. Indeed, it
appears as though the crossing of the tree line is a step which requires
greater stimulation than a mere rise in temperature of one or two degrees.
It is in fact probable that birds which habitually breed up to the limit of
trees will not move farther north except as the tree limit does, and the
latter movement is of course slow. There are occasional records of conifer–
forest birds from well north of the tree line, such as that of a magpie ( Pica
pica hudsonia ) (22) from the Dubawnt River area, Northwest Territories, but
it is very doubtful whether such strays can be accepted as evidence of a true
extension of normal range.
Before leaving the subject of the possible effects of recent climatic
change upon the terrestrial fauna, which effects, as w e i ll be apparent from

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

the somewhat scant evidence available, are not well marked nor with any
certainty related to the climate, mention should be made of an interesting
development in Greenland which seems to demonstrate a physiological effect
of increasing temperatures and general amelioration of climate. Faester (9)
has shown that the percentage of “summer skins,” or skins with thin fur
more or less dominated by brownish color, in the commercial take from South
Greenland has increased since 1929 from between 1.5 and 5% to 21% in 1938.
This increase is not due to any alternation in the trapping season, nor to
any change in handling of the skins for the Danish market. It represents
an actual difference in the state of color change of the white and blue
fox population during the trapping season, and Faester has related it to
the milder climate. It is interesting to note that the increase in the
pop proportion of “summer skins” in the catch occurred not during the
period following the greatest rise, in the decade of the 1930’s, when the
mean temperatures began to level off. This suggests that it is not the
direct effect of temperature that is concerned, but an indirect effect,
perhaps working through general conditions of nutrition.
Marine Fauna
The effects of change in the marine climate are clearly more immediate
than those on land. The whole environment is affected simultaneously, over
large areas, and there are few microclimates to build up special local
conditions which obscure the picture as a whole. Marine organisms, as has
already been pointed out, are for the most part very sensitive to small
changes in temperature, much more so than terrestrial animals.
Following immediately upon the hydrographic changes described above,
brought about mainly by an increase in the heat and transport of the Gulf

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

Stream and North Atlantic Drift, there occurred sweeping changes in the
fauna of the waters from Siberia westward to Baffin Bay. In the Barents
Sea, the Atlantic cod ( Gadus callarias ) appeared much farther east in 1921
than formerly, and continued to spread eastward. Along the Murman Coast,
this eastward spread was observed in a great variety of animals, including
the mollusk Cardium edule , and the echinoderm Echinus esculentus . Arctic
species of fishes, such as Leptagonus decagonus and Gymnacanthus tricuspis ,
have become scarce in this Murman area, and have been replaced by Atlantic
species, such as Zeugopterus norvegicus and Chirolophus galerita , and even
the mackerel ( Scomber scombrus ) and the herring ( Clupea harengus ) have
become abundant. The herring, mackerel, and coalfish ( Gadus virens ) were
reported for the first time from the west coast of Novaya Zemlya in 1936,
by Agapov and Toporkov (1), who write: “The appearance of these fishes,
aliens to the Arctic, is caused by the same factors as the appearance of
the cod and some other fishes in the Kara Sea, namely the general warm spell
of the past few years” (Agapov and Toporkov, quoted from Jensen) (15). The
Atlantic salmon ( Salmo salar ) was found to have invaded the Kara River in 1932.
The fisheries of northern Norway have been greatly increased during the
present warm period, and the important cod fisheries around Bear Island and
in the waters west and south of Spitsbergen are entirely a product of this
warming effect. The contrast in the Norwegian fisheries today and those of
the preceding colder period are well expressed in the following quotation
from Jensen (15):
“During the cold period something happened, which was diametrically
opposite to what occurred in the following warm period. In the years 1902
and 1903 arctic animals, such as the Greenland Seal ( Phoca groenlandica ),

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

the Ringed Seal ( Phoca foetida ) and the White Whale ( Delphinapterus leucas ),
whose mass-wanderings are otherwise restricted to purely arctic regions,
came down in enormous schools to the northern coasts of Norway and farther
also along the west coast. Previously the fixed ice-boundary had advanced
farther west and south than any one could remember; even in May 1902 it
extended as a continuous wall from Spitsbergen and Bear Island down towards
the Murman coast, not far from Varanger Fjord, presumably owing to the
prevailing northerly and easterly winds over Spitsbergen and the Barents Sea.
The temperature of the sea and air was noted as low. The special meteorological
and hydrographical conditions in conjunction with the advance of the ice were
taken to be the cause of the mass-incursion of arctic animals to Norway.
At the same time the great cod fisheries in the northern district of Norway
were a failure and the fishermen believed that the arrival of the seals had
driven the cod from the coast. It might be questioned, however, whether it
was not the changed natural conditions, which enabled the arctic seals and
whales to thrive on the northern coasts of Norway, which had the opposite
influence on the boreal cod and forced them to go elsewhere.”
The history of the Spitsbergen fishery is recorded elsewhere in this
Encyclopedia . It will be enough here to mention that between its beginning
in 1874 and the present day, there was a period, from 1883 to 1926, when
colder conditions returned and the fishery disappeared.
In the waters around Jan Mayen, Atlantic cod and herring were taken in
1930 and 1931, but not in commercial quantities. The Michael Sars expedition
of 1900, under the direction of Johan Hjort, had found no food fishes at
Jan Mayen.
Perhaps the most spectacular of all these faunal changes has taken place

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

in the waters of Greenland, especially West Greenland, owing to the increased
activity and heat content of the Irminger Current, a branch of the North
Atlantic Drift, which turns north and then west, in the region southwest
of Iceland, to meet the cold East Greenland Current and, together with the
latter, taking part in the formation of the West Greenland Current. The
list of Atlantic animals that have appeared or increased in range in West
Greenland waters since the beginning of the warm period (about 1917) is
large, and includes the following:
Atlantic cod appeared in increasing quantities and farther north each
year. This process, with the associated development of fisheries in Greenland,
is described in detail elsewhere (see “Greenland Fisheries”). The cod
came originally from Iceland, and gradually became established as a breeding
stock in the fjords and on the banks of West Greenland. In 1929, a haddock
( Gadus aeglefinus ) was caught in the Julianehaab district, a species which
had never before been recorded from Greenland waters. The haddock has not
become abundant, but other specimens have occasionally been caught since
1929. In 1936, another first record was made, when the brosme ( Brosmius
brosme ) was [: ] taken in the Holsteinsborg district. The ling ( Molva
vulgaris ) was first caught in 1928, in the Frederikshaab district, and
the Atlantic halibut ( Hippoglossus vulgaris ), known previously only from
the banks south of Davis Strait, has invaded the Baffin Bay coast of West
Greenland, at least as far as the Upernivik district. The herring, pre–
viously known in small numbers in the extreme southwest of Greenland, has
increased its range northward at least as far as the Umanak district on
the west coast, and was first recorded on the east coast in 1932, from the
Angmagssalik area. It has since been seen in Scoresby Sound. The spiny

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

dogfish ( Squalus acanthias ), formerly rare in Greenland waters, has appeared
in greater numbers from the south. The rosefish, or Norway haddock ( Sebastes
marinus ), has become plentiful, and has now been shown to breed in West
Greenland waters (15).
Certain fishes, previously common in the waters of the southern part
of Greenland, have moved northward during the present period of warmer condi–
tions. This class includes the Greenland or fjord cod ( Cadus ogac ), which
has become increasingly scarce in South Greenland and more abundant in the
north; and the capelin ( Mallotus villosus ), which was formerly most abundant
in the area south of Disko Bay on the west coast and of Angmagssalik on the
east coast, and has now moved the gravity point of its distribution farther
north. The capelin is now known from Thule and from Scoresby Sound. Probably
as a result of this movement in the capelin population population, the harp seal ( Phoca
groenlandica ) is now common in the northern part of West Greenland than
in the south.
One whale, the pilot whale, blackfish, or ca’ing whale ( Globicephala
ventricosa ), formerly Globiceps melas ), has appeared in West Greenland waters
in recent years, as far north as Disko Bay.
These are the most obvious increases in fauna, or in faunal range, in
Wet Greenland waters. There are also many planktonic animals and plants
which have invaded the West Greenland Current under the greater Irminger
Current influence. Jensen (15) mentions the medusa Halopsis ocellata as
an example, first recorded by Kramp (18) from collections made in 1928.
Another good example, also a coelenterate, recorded by Kramp is Hybocodon
prolifer , another Atlantic form first taken in West Greenland by the Godthaab
expedition in 1928 (17).

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

As would be expected, the invasion of Atlantic forms has been accompanied
by a retreat of the strictly arctic animals. This is best exemplified by the
northward retreat, in West Greenland, of the beluga or white whale, and the
narwhal ( Monodon monoceros ), both of which are now rare south of Disko Bay.
The Greenland or arctic halibut ( Reinhardtius hippoglossoides ) is another
arctic-water species that has become much more scarce in southwest Greenland
since the 1920’s.
In the Canadian waters of the eastern arctic, faunistic changes are
much less marked than in West Greenland, in accordance with the lesser degree
of hydrographic change. Indeed, it is not possible to point to a single in–
stance of northward extension of range, or of retreat northward, with any
degree of certainty, partly because of the absence of good past faunal records.
It is generally reported that the ringed seal ( Phoca hispida = Phoca foetida )
is now less abundant in Ungava Bay and the region south of Hudson Strait
than in former decades, but figures are lacking, and moreover if any decrease
has in fact taken place, it is more than possible that it is due to human
activity. Decreasing numbers of ringed seal have even been reported by
residents in southern Baffin Island, but again, if the decrease is true, it
is not possible to ascribe it to hydrographic change. The same applies to
the drastic reduction in the distribution range of the Atlantic walrus
( Odobenus rosmarus ) in the past hundred years (see “Arctic and Subarctic Seals”).
The coelenterate Hybododon prolifer , mentioned above as being first
found in West Greenland in 1928, was taken in large numbers in Lake Harbour
Inlet, southern Baffin Island, in 1939 and 1940 (7) (see “Marine Plankton”).
It is impossible to know how long it has been there, but since it was not
found in the well-worked Greenland waters until 1928, it is very probable

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

that it is a fairly recent arrival in Hudson Strait. It has since been taken
in numbers in Ungava Bay (unpublished date).
The capelin, whose distribution has been altered in West Greenland, is
also of interest in this respect in the Canadian waters. It is most abund–
dant in the northern waters of Newfoundland, and along the Labrador, particu–
larly in the southern part. In four seasons of collecting in Ungava Bay, the
present writer obtained only two specimens of Mallotus , and it is not known
to the present-day Eskimos of that region. Lucien Turner, however, visiting
Ungava Bay in the years 1882-84, records in his manuscript report (27) on the
fishes (never yet published; the auther is here indebted to the Smithsonian
Institution for the loan of the manuscript) that capelin had not been recorded
within Hudson Strait until several years previous to 1884 “when a few were
seen in the neighboring waters of George’s River.” Continuing the quotation
from the Turner manuscript: “In the spring of 1884 they were observed in
great numbers in that vicinity [George’s River, or, more properly, George
River]. On the 8th of August 1884 a school of several thousand individuals
appeared four miles within the mouth of the Koksoak River. As many as were
desired for specimens were secured by the hand as they swam near the shore….
This is the first instance known either to whites or natives of the appearance
of capelin in the southern portion of Ungava Bay. They are well known to the
Eskimo, who apply the name Kolelekuk to the caplin” (Turner 1885).
It is at once clear that faunal conditions in Ungava Bay in 1884 were
different from conditions in 1950. Capelin are now very rare, and they are
not known to the natives. They are North Atlantic fishes, edging into the
Subarctic, and they are seldom seen in swarms in water of temperature below
6°C. (25), although they have recently been observed in very large numbers

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

in 2°C. water in southeastern Newfoundland waters (Templeman, private
communication). At all events, the presence of capelin in large numbers
in Ungava in 1884 is a general indication of warmer conditions in the
water than exist at present. And yet, as has been recorded above, Turner
met with much more severe ice conditions in 1882 than are known today. It
is much to be deplored that routine temperature and salinity observations
were not kept at regular intervals in the eastern arctic of Canada in past
decades, because it is obvious that the history of hydrography and faunal
distribution in those waters has been varied, and the evidence brought
together here shows that the relations between atmospheric and marine
climate, and marine fauna, may not have been simple.

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

BIBLIOGRAPHY

1. Agapov, I.D., and Toporkov, G.N. “Some data concerning the fishes
of Novaya Zemlya.” Problems of the Arctic, vol.2, p.108.
Leningrad, 1937. (In Russian)

2. Ahlmann, H. “The present climate fluctuation.” Geogr.Jour ., CXII
(4-6), pp.165-193, 1949.

3. Anderson, R.M. “Catalogue of Canadian recent mammals.” Nat.Mus .
Canada., Bull . No.102, 1946.

4. ----. “Report on the natural history collections of the expedition,”
Stefansson’s My Life with the Eskimo , Macmillan, New York,
1913.

5. Bailey, W.B., and Hachey, H.B. “An increasing Atlantic influence in
Hudson Bay.” Joint Committee on Oceanography, St.Lawrence,
N.B. 11 pp. (mimeographed). 1949.

6. Dunbar, M.J. “Eastern Arctic Waters.” Fish.Res.Bd. Canada, Bull. No.88,
1951.

7. ----. “Marine macroplankton from the Canadian Eastern Arctic. II.
Medusae, et.” Can.J.Research , D, 20, pp.71-77, 1942.

8.----. “The state of the West Greenland current up to 1944.” Fish.Res.Bd .,
Canada, Jour . VI (7), pp.460-471, 1946.

9. Faester, K. “Effect of the climatic amelioration of the past decade on
the autumn change of coat of the arctic fox in Greenland.”
Medd.Grønl . vol.142 (2), 1945.

10. Griscom, L. The Birds of Concord . Cambridge, Mass., Harvard University
Press, 1949.

11. ---. Modern Bird Study . Cambridge Mass., Harvard University Press, 1945.

12. Hare, F.K. “The climate of the eastern arctic and subarctic of Canada
and its influence on accessibility.” Report for the Government
of Canada (Manuscript), 1950.

13. Helland-Hansen, B., and Nansen, F. “Temperature variations in the North
Atlantic Ocean and in the atmosphere.” Videnskapselskapets
Skrifter, I. , Mat.-Naturv. Klasse, 1916 (9).

14. Hubbs, C.L. “Changes in the fish fauna of western North America correlated
with changes in ocean temperature.” J.Mar.Res. , VII (3),
pp.459-480, 1949.

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

Bibliography

15. Jensen, Ad. S. “Concerning a change of climate during recent decades
in the arctic and subarctic…, etc.” Det.Kgl.Danske Vidensk .
Selsk., Biol Medd. , XIV (8), 1939.

16. Kiilerich, A.B. “The hydrography of the west Greenland fishing banks.”
Medd. fra Komm.Danm.Fisk. og Havunders. , Ser Hydrografi, 3 (3),
1943.

17. Kramp, P.L. “Medusae (Godthaab Expedition 1928).” Medd.Grøn ., vol.81
(1), 1942.

18. ----. “A revision of the Medusae belonging to the Family Mitrocomidae”
Vidensk. Medd.Dansk Naturh.Foren ., 92, pp.305-384, 1932.

19. Lauzier, L. “Unusually warm surface sea-water in 1949.” Fish.Res.Bd.
Canada, Progress Rep . Atlantic Coast Stations, No.51, p.17,
1950.

20. MacFarlane, R. “Notes on the mammals collected and observed in the
northern Mackenzie district, Northwest Territories.” Proc .
U.S. Nat.Mus., 28, pp.673-764, 1905.

21. Rand, A.L. “The mammals of northern Canada from a utilization viewpoint.”
Report for the Government of Canada. (Manuscript). I-XIV,
pp.1-809, 1949.

22. ----. “Northern records of the magpie, Pica pica hudsonia (Sabine).”
Can.Field-Nat ., 59 (1), p.45, 1945.

23. Soper, J.D. “The mammals of southern Baffin Island, Northwest Territories,
Canada.” J.Mamm. , 25 (3), pp.221-254, 1944.

24. Sutton, G.M., and Hamilton, W.J. “The mammals of Southampton Island.”
Mem. Carn.Mus., 12 (2), 1932.

25. Templeton, W. “The life history of the Chaplin ( Mallotus villosus O.F.
Müller) in Newfoundland waters.” Bull . Nfld.Govt.Lab.,
No.17 (Research), 1948.

26. Tully, J.P. “Seasonal cycles in the sea.” Fisheries Res.Bd. Canada,
Progress Rep . Pacific Coast Stations, No.85, pp.88-90, 1950.

27. Turner, L.M. “Fishes.” (Manuscript report deposited in the Smithsonian
Institution, Washington, D.C.), 1885.

Max M. J. Dunbar

Faunistic Effects of Climatic Change in the North (repeated)

EA-Zoology
( Max M. J. Dunbar)

FAUNISTIC EFFECTS OF CLIMATIC CHANGE IN THE NORTH

CONTENTS
Page
Introduction 1
Fauna of the Land 6
Marine Fauna 10
Bibliography 17

EA-Zoology
(Max J. Dunbar)

FAUNISTIC EFFECTS OF CLIMATIC CHANGE IN THE NORTH
Introduction
During the past thirty or more years there have been changes in the
climate of the arctic and subarctic regions, manifested in a progressive
warming in both the atmosphere and the hydrosphere. Clearly the atmos–
pheric and marine climates are interrelated, but the mechanism of the
relation, and the causal paths involved, are at present uncertain. These
effects have altered the distribution of plants and animals, resulting in
a general northward extension of distribution, which is much more immediately
apparent in the sea than in terrestrial environments.
The whole matter of recent climatic change has been reviewed by
Ahlmann (2) in a paper in which the climatological, glaciological, oceano–
graphic, and biological evidence for the recent warming is brought together,
and some years previous to Ahlmann’s paper, Jensen (15) made an extensive
review of the pattern of change, particularly as it affected West Greenland.
Both papers contain extensive bibliographic lists to which the reader is
referred. The increase in atmospheric temperatures has affected the whole
of the Northern Hemisphere, in all probability, but information from certain
parts of the North is lacking. Ahlmann has emphasized the urgency of the need
for the study of this change in greater detail, and has brought home the fact

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

that “here is something happening” which affects all of us, both at present
and in the immediate future.
The underlying cause of the present warming effect, and indeed of longer-
term variations and fluctuations in climate, is not certain, but as early as
1916, Helland-Hansen and Nansen suggested that the terrestrial climatic
variations must ultimately becaused by variations in solar radiation; that
increased solar radiation set up increased atmospheric movement, and thus the
faster transmission of energy from the tropics to the poles. That climatic
variation is normal is obvious from a consideration of the geologic past of
the earth, and Ahlmann (2) has summarized the effects of recent (post glacial)
variations in northwest Europe, Iceland, and Greenland, areas in which it is
clear that the human economy within historic times has been greatly dependent
upon climatic conditions.
In the atmospheric climate, the most spectacular changes in recent
decades have perhaps taken place in Spitsbergen, where there has been an
increase of no less than 9°C. in the mean winter temperature between the
period 1911-15 and 1931-35, the actual figures being −17.6°C. for the earlier
period and −8.6°C. for the later. In Greenland, the winter temperatures at
Jakobshavn during the period 1923-32 were more than 5°C. warmer than those
registered fifty years before, and there has been a steady rise since 1932.
Positive deviations from the former mean temperature, of from 2 to 4 degrees,
are the rule at all Greenland stations. In Canada, information on atmospheric
temperatures has recently been brought together by Hare (1950) in an exhaustive
study of the climate of the Canadian eastern Arctic and Subarctic. At Moose
Factory, Southwest Point (Anticosti Island), and St. John’s, Newfoundland,
the coldest period is shown to have been about the year 1915, since which

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

time there has been a slight rise of one or two degrees Fahrenheit in both
winters and summers. It was warmer in 1870-1910 than between 1915-20.
Such information as is available from northern stations in the eastern
arctic of Canada (Craig Harbour, Pond Inlet) also shown an increasing
temperature. The warming effect is, however, not so marked in Canada as in
Greenland and (especially) Spitsbergen; in fact, the effect is to some extent
related to the maritime nature of the climate. In the U.S.S.R., (Rubenstein,
quoted from Ahlmann 1949) (2), “it appears that an increase in winter tempera–
tures began about the latter part of the nineteenth century, and that it was
especially marked at such northern stations as Kola, Archangel and Leningrad,
while no increase was noticeable, for example, at Kiev.”
Glaciers all over the world are now receding, for example, a with
perhaps a few exceptions, and at varying rates. Recession appears to be
slow in Greenland, but in southern Alaska, Iceland, and Norway the decrease
in glacier size is impressive.
The pattern is similar in the marine climate, that is to say in the
temperature of sea water, at least in the North Atlantic and associated seas.
In the North Pacific arctic and subarctic area, the picture is uncertain due
to the lack of extended records with which to compare present observations,
but there is evidence of an increase in temperatures off the southern
California coast in recent decades (14), and in the coastal waters of British
Columbia (26). The marine change is perhaps most marked in West Greenland,
where the water has been growing warmer since about 1917, apparently owing to
a strengthening of the Irminger Current component in the West Greenland
Current (Jensen 1939, Kiilerich 1943, Dunbar 1946 and 1951). The Gulf
Stream itself has increased in temperature about half a degree centigrade,

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

at its origin in the Straits of Florida. The southern limit of ice in
the Greenland Sea (east of Greenland) retreated some 200 to 300 kilometers
between the years 1928 and 1936, and the thickness of the ice in the Polar
Sea decreased “from an average of 365 cm. during the Hansen Fram expedition
of 1893-96 to 218 cm. during the drift of the Russian ice-breaker Sedov in
1937-40” (2). In the Norwegian Sea, there appears to have been an increase
in both the volume and the temperature of the Atlantic water flowing northward,
of 2°C., compared with conditions at the beginning of the present century, and
Ahlmann (2) quotes Russian work on routine hydrographic sections along the
Kola meridian (33 1/2°E.), which showed an increase of the order of 2°C. in
the temperature at 200 meters between 1900 and 1921; the earming has been
continuing since 1921. A rise in temperature of the same extent has been
demonstrated in Spitsbergen waters, and the shipping season in West Spitsbergen
has been more than doubled since 1900. It appears, also, that the ice condition [: ]
along the Siberian shelf have been easing during the past decades.
In the Canadian eastern arctic, there is a lack of past records. It is
reasonable to suppose that the waters off southeast Baffin Island, in Hudson
Strait, and along the Labrador, have been influenced by the warming of the
West Greenland Current, most of which turns westward, south of the submarine
ridge between Greenland and Baffin Island, and takes part in the formation
of the Labrador Current. There is evidence of a biological nature (see below)
for the invasion of Atlantic water into Hudson Strait. The only physical
evidence is in the comparison between temperature and salinity measurements
made in Hudson Bay and Strait in 1930, by the Fisheries Expedition, and those
made in 1948 by the H.M.C.S. Haida. Working on these data, Bailey and Hachey
(5), and Dunbar (6) have shown that there must have been a significant increase
in both parameters between the years mentioned, which may perhaps be put down

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

to an increased influence of Atlantic water, as in West Greenland.
There is some evidence also to be gained from comparisons of the
open-water seasons for shipping in Hudson Strait and Ungava Bay in past
years and at present. According to all reports and the memory of Older
residents in the eastern arctic, the possible season for navigation into
and and out of Ungava Bay, some 20 to 30 years ago, was little more than
two to two-and-one-half months, or between the beginning of August and some
time in October. Today the open water season is much longer, extending from
the middle of July (earlier inside the bay itself) to late November at least,
probably well into December. Lucien Turner, who visited Fort Chimo in 1882-
84, records in his 1885 manuscript (27) that his ship was caught in the ice
at the beginning of August 1882, off the mouth of the George River; this
could hardly happen during the present years, when all the ice is out of
Ungava Bay by the middle of July.
Farther south in Canada, exceptionally high surface temperatures have
been recorded along the Atlantic coast in 1947 and 1949 (19), phenomena
which appear to be part of a general pattern of warming.
In this general process there have of course been relapses. In 1938
there was a very cold season in West Greenland, and the winter of 1948-49
was one of the coldest on record. In the Siberian waters, ice conditions
were bad in 1933, 1934, and 1936 (2), in the Kara Sea, and in 1942 they were
again bad, worse along the whole northern route than at any time in recent
years. There are similar variations in the ice conditions in the Canadian
eastern arctic. It has been suggested by the present writer (8) that there
has not been any significant increase in water temperatures in West Greenland
since about 1936, and that it is possible that the present warm period is

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

leveling off. It is much too early yet to form any firm opinion, or to
attain any sort of certainty on this point. Surface temperatures in Georgia
Strait, British Columbia, have been falling somewhat since 1940 (26).
Fauna of the Land
A warning should be sounded at the beginning of this section to the
effect that ( 1 ) recent northward extensions of distribution in terrestrial
fauna may not be caused by climatic change at all, at least in the obvious
and direct sense, and ( 2 ) if there is an important element of climatic
control, climatic change in the atmosphere may be long in inducing change
in distribution of animals; there may be a considerable time lag. Terrestrial
animals are not, for the most part, so delicately adjusted to environmental
temperature conditions as are aquatic animals.
The first possibility, that direct climatic control may not be involved,
follows from the fact that the areas that fall within the terms of reference
of this encyclopedia have generally been recently freed from a covering of
ice. Once the ice has retreated, the processes of soil formation will continue,
albeit at rates controlled by the climate, no matter whether the climate is
cooler or warmer. As soil formation proceeds, so will colonization by plants
and by animals. The rate of colonization (which is manifested by northward
extensions of distribution) will depend on climatic variation, but the mere
fact of northward extension does not necessarily imply a causal connection
with present climatic warming.
The fact that terrestrial animals, and especially the homotherms (birds
and mammals), are less delicately adjusted to temperature differences than
are aquatic animals, is demonstrated in an a priori manner by the failure
of the “life-zone” concept in classifying or formalizing the distribution

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

of life in North America. Founded upon temperature conditions alone,
Merriam’s original life zones are of only very general value, little more
than a useful descriptive convention. Nevertheless, it is clear that the
complex of factors which does control the distribution of animals is at some
point concerned with the atmospheric temperature aved average. Griscom (11),
in criticizing the life-zone system as applied to the distribution of birds,
seems to swing too far in the other direction, and to place too little impor–
tance upon temperature. He says, for instance: “In my lifetime various birds
have been steadily pushing northward and northeastward, and it follows, con–
sequently, that the present isothermal lines of their northernmost limits
are very much cooler than the isothermal lines that constituted limits
twenty-five years ago. In other words, it is obvious that temperature has
not limited the northward distribution of these birds in any way whatsoever.”
(11) p.160). The reclamation by birds of previously glaciated territory is
no doubt keeping pace with the reclamation by plants and other organisms,
but the influence of temperature upon the rate of that reclamation cannot
be ignored. With this preliminary warning of the limits of our present
knowledge, examples of recent northward extensions in the distributions of
organisms can be discussed.
The effect is of course not restricted to the arctic and subarctic
regions, but it is with these regions only that we are concerned here.
Griscom (10; 11) has mentioned several birds which have spread northward
in the United States recently, and Hubbs (14) has studied the question of
recent changes in the distribution of marine fish in the pacific coastal
waters, also of the United States.
Northward creep of vegetation has been observed in Iceland and in

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

Norway, Sweden, and Finland. “In the forests of northern Scandinavia the
economic benefits are of special importance. The trees are spreading
rapidly above their former limits, and the annual rings of both pine and
spruce show a quicker growth than they have for about two decades… Large,
formerly bare areas are now being [: ] invaded principally by birch and
willow; the timberline of the mountain birch is rising higher and higher.
Vegetation in general is becoming more luxuriant” (2). A similar creep
northward of the tree line has been observed in Alaska. A similar studies
of the tree line in northern Canada do not appear to have been published,
but the northward movement of certain mammals has been observed.
Rand (21) describes the coyote ( Canis latrans ) as the best example of
recent change in status and distribution. The coyote has “within the present
century…greatly extended its range northward and eastward and now occurs
as far north as the arctic ocean.” It is now known at Point Barrow, Alaska,
and in the Mackenzie Delta area. The red fox ( Vulpes fulva ) has been
gradually extending its range beyond the tree line and well into the edge
of the barren grounds. It is now recorded from southern Baffin Island (23)
and from Southampton Island (24). Whether this extension of range is
strictly referable to the climatic “amelioration” is uncertain; it might
conceivably be due to increased pressure from human populations farther
south.
The moose ( Alces americana ) was described by Anderson (4) as increasing
rapidly in numbers at that date, and also as extending its range northward,
in the Mackenzie district. Again in 1924, Anderson recorded similar events
in the moose population. The moose had formerly, according to Macfarland (20),
been scarce in this region. Rand (21) doubts whether this increase in numbers

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

and in range of the moose can be ascribed to climatic factors, and is
inclined instead to suppose that such fluctuations in the moose population
are due to a combination of other factors, such as parasites, disease, and
activities of man.
The activities of man in the cultivation of the land, farther south
than our present area, have long been known to affect the range of birds
and mammals. The movement northward of the white-tailed deer ( Odocoileus
virginianus borealis ) following the cutting of its native coniferous forests,
is such an example which should be mentioned here (3, p.7). Reduction in the
northern forests may also be related to the extensions of range in the coyote
and red fox, already mentioned, and in the apparent gradual colonization of
the barren lands by the wolverine (Gulo luscus).
Among birds, there are many examples of northward extension of breeding
ranges in the temperate parts of the Northern Hemisphere, including Iceland,
but evidence of such extension in the Arctic seems to be scarce. Indeed, it
appears as though the crossing of the tree line is a step which requires
greater stimulation than a mere rise in temperature of one or two degrees.
It is in fact probable that birds which habitually breed up to the limit of
trees will not move farther north except as the tree limit does, and the
latter movement is of course slow. There are occasional records of conifer–
forest birds from well north of the tree line, such as that of a magpie ( Pica
pica hudsonia ) (22) from the Dubawnt River area, Northwest Territories, but
it is very doubtful whether such strays can be accepted as evidence of a true
extension of normal range.
Before leaving the subject of the possible effects of recent climatic
change upon the terrestrial fauna, which effects, as w e i ll be apparent from

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

the somewhat scant evidence available, are not well marked nor with any
certainty related to the climate, mention should be made of an interesting
development in Greenland which seems to demonstrate a physiological effect
of increasing temperatures and general amelioration of climate. Faester (9)
has shown that the percentage of “summer skins,” or skins with thin fur
more or less dominated by brownish color, in the commercial take from South
Greenland has increased since 1929 from between 1.5 and 5% to 21% in 1938.
This increase is not due to any alternation in the trapping season, nor to
any change in handling of the skins for the Danish market. It represents
an actual difference in the state of color change of the white and blue
fox population during the trapping season, and Faester has related it to
the milder climate. It is interesting to note that the increase in the
pop proportion of “summer skins” in the catch occurred not during the
period following the greatest rise, in the decade of the 1930’s, when the
mean temperatures began to level off. This suggests that it is not the
direct effect of temperature that is concerned, but an indirect effect,
perhaps working through general conditions of nutrition.
Marine Fauna
The effects of change in the marine climate are clearly more immediate
than those on land. The whole environment is affected simultaneously, over
large areas, and there are few microclimates to build up special local
conditions which obscure the picture as a whole. Marine organisms, as has
already been pointed out, are for the most part very sensitive to small
changes in temperature, much more so than terrestrial animals.
Following immediately upon the hydrographic changes described above,
brought about mainly by an increase in the heat and transport of the Gulf

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

Stream and North Atlantic Drift, there occurred sweeping changes in the
fauna of the waters from Siberia westward to Baffin Bay. In the Barents
Sea, the Atlantic cod ( Gadus callarias ) appeared much farther east in 1921
than formerly, and continued to spread eastward. Along the Murman Coast,
this eastward spread was observed in a great variety of animals, including
the mollusk Cardium edule , and the echinoderm Echinus esculentus . Arctic
species of fishes, such as Leptagonus decagonus and Gymnacanthus tricuspis ,
have become scarce in this Murman area, and have been replaced by Atlantic
species, such as Zeugopterus norvegicus and Chirolophus galerita , and even
the mackerel ( Scomber scombrus ) and the herring ( Clupea harengus ) have
become abundant. The herring, mackerel, and coalfish ( Gadus virens ) were
reported for the first time from the west coast of Novaya Zemlya in 1936,
by Agapov and Toporkov (1), who write: “The appearance of these fishes,
aliens to the Arctic, is caused by the same factors as the appearance of
the cod and some other fishes in the Kara Sea, namely the general warm spell
of the past few years” (Agapov and Toporkov, quoted from Jensen) (15). The
Atlantic salmon ( Salmo salar ) was found to have invaded the Kara River in 1932.
The fisheries of northern Norway have been greatly increased during the
present warm period, and the important cod fisheries around Bear Island and
in the waters west and south of Spitsbergen are entirely a product of this
warming effect. The contrast in the Norwegian fisheries today and those of
the preceding colder period are well expressed in the following quotation
from Jensen (15):
“During the cold period something happened, which was diametrically
opposite to what occurred in the following warm period. In the years 1902
and 1903 arctic animals, such as the Greenland Seal ( Phoca groenlandica ),

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

the Ringed Seal ( Phoca foetida ) and the White Whale ( Delphinapterus leucas ),
whose mass-wanderings are otherwise restricted to purely arctic regions,
came down in enormous schools to the northern coasts of Norway and farther
also along the west coast. Previously the fixed ice-boundary had advanced
farther west and south than any one could remember; even in May 1902 it
extended as a continuous wall from Spitsbergen and Bear Island down towards
the Murman coast, not far from Varanger Fjord, presumably owing to the
prevailing northerly and easterly winds over Spitsbergen and the Barents Sea.
The temperature of the sea and air was noted as low. The special meteorological
and hydrographical conditions in conjunction with the advance of the ice were
taken to be the cause of the mass-incursion of arctic animals to Norway.
At the same time the great cod fisheries in the northern district of Norway
were a failure and the fishermen believed that the arrival of the seals had
driven the cod from the coast. It might be questioned, however, whether it
was not the changed natural conditions, which enabled the arctic seals and
whales to thrive on the northern coasts of Norway, which had the opposite
influence on the boreal cod and forced them to go elsewhere.”
The history of the Spitsbergen fishery is recorded elsewhere in this
Encyclopedia . It will be enough here to mention that between its beginning
in 1874 and the present day, there was a period, from 1883 to 1926, when
colder conditions returned and the fishery disappeared.
In the waters around Jan Mayen, Atlantic cod and herring were taken in
1930 and 1931, but not in commercial quantities. The Michael Sars expedition
of 1900, under the direction of Johan Hjort, had found no food fishes at
Jan Mayen.
Perhaps the most spectacular of all these faunal changes has taken place

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

in the waters of Greenland, especially West Greenland, owing to the increased
activity and heat content of the Irminger Current, a branch of the North
Atlantic Drift, which turns north and then west, in the region southwest
of Iceland, to meet the cold East Greenland Current and, together with the
latter, taking part in the formation of the West Greenland Current. The
list of Atlantic animals that have appeared or increased in range in West
Greenland waters since the beginning of the warm period (about 1917) is
large, and includes the following:
Atlantic cod appeared in increasing quantities and farther north each
year. This process, with the associated development of fisheries in Greenland,
is described in detail elsewhere (see “Greenland Fisheries”). The cod
came originally from Iceland, and gradually became established as a breeding
stock in the fjords and on the banks of West Greenland. In 1929, a haddock
( Gadus aeglefinus ) was caught in the Julianehaab district, a species which
had never before been recorded from Greenland waters. The haddock has not
become abundant, but other specimens have occasionally been caught since
1929. In 1936, another first record was made, when the brosme ( Brosmius
brosme ) was [: ] taken in the Holsteinsborg district. The ling ( Molva
vulgaris ) was first caught in 1928, in the Frederikshaab district, and
the Atlantic halibut ( Hippoglossus vulgaris ), known previously only from
the banks south of Davis Strait, has invaded the Baffin Bay coast of West
Greenland, at least as far as the Upernivik district. The herring, pre–
viously known in small numbers in the extreme southwest of Greenland, has
increased its range northward at least as far as the Umanak district on
the west coast, and was first recorded on the east coast in 1932, from the
Angmagssalik area. It has since been seen in Scoresby Sound. The spiny

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

dogfish ( Squalus acanthias ), formerly rare in Greenland waters, has appeared
in greater numbers from the south. The rosefish, or Norway haddock ( Sebastes
marinus ), has become plentiful, and has now been shown to breed in West
Greenland waters (15).
Certain fishes, previously common in the waters of the southern part
of Greenland, have moved northward during the present period of warmer condi–
tions. This class includes the Greenland or fjord cod ( Cadus ogac ), which
has become increasingly scarce in South Greenland and more abundant in the
north; and the capelin ( Mallotus villosus ), which was formerly most abundant
in the area south of Disko Bay on the west coast and of Angmagssalik on the
east coast, and has now moved the gravity point of its distribution farther
north. The capelin is now known from Thule and from Scoresby Sound. Probably
as a result of this movement in the capelin population population, the harp seal ( Phoca
groenlandica ) is now common in the northern part of West Greenland than
in the south.
One whale, the pilot whale, blackfish, or ca’ing whale ( Globicephala
ventricosa ), formerly Globiceps melas ), has appeared in West Greenland waters
in recent years, as far north as Disko Bay.
These are the most obvious increases in fauna, or in faunal range, in
Wet Greenland waters. There are also many planktonic animals and plants
which have invaded the West Greenland Current under the greater Irminger
Current influence. Jensen (15) mentions the medusa Halopsis ocellata as
an example, first recorded by Kramp (18) from collections made in 1928.
Another good example, also a coelenterate, recorded by Kramp is Hybocodon
prolifer , another Atlantic form first taken in West Greenland by the Godthaab
expedition in 1928 (17).

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

As would be expected, the invasion of Atlantic forms has been accompanied
by a retreat of the strictly arctic animals. This is best exemplified by the
northward retreat, in West Greenland, of the beluga or white whale, and the
narwhal ( Monodon monoceros ), both of which are now rare south of Disko Bay.
The Greenland or arctic halibut ( Reinhardtius hippoglossoides ) is another
arctic-water species that has become much more scarce in southwest Greenland
since the 1920’s.
In the Canadian waters of the eastern arctic, faunistic changes are
much less marked than in West Greenland, in accordance with the lesser degree
of hydrographic change. Indeed, it is not possible to point to a single in–
stance of northward extension of range, or of retreat northward, with any
degree of certainty, partly because of the absence of good past faunal records.
It is generally reported that the ringed seal ( Phoca hispida = Phoca foetida )
is now less abundant in Ungava Bay and the region south of Hudson Strait
than in former decades, but figures are lacking, and moreover if any decrease
has in fact taken place, it is more than possible that it is due to human
activity. Decreasing numbers of ringed seal have even been reported by
residents in southern Baffin Island, but again, if the decrease is true, it
is not possible to ascribe it to hydrographic change. The same applies to
the drastic reduction in the distribution range of the Atlantic walrus
( Odobenus rosmarus ) in the past hundred years (see “Arctic and Subarctic Seals”).
The coelenterate Hybododon prolifer , mentioned above as being first
found in West Greenland in 1928, was taken in large numbers in Lake Harbour
Inlet, southern Baffin Island, in 1939 and 1940 (7) (see “Marine Plankton”).
It is impossible to know how long it has been there, but since it was not
found in the well-worked Greenland waters until 1928, it is very probable

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

that it is a fairly recent arrival in Hudson Strait. It has since been taken
in numbers in Ungava Bay (unpublished date).
The capelin, whose distribution has been altered in West Greenland, is
also of interest in this respect in the Canadian waters. It is most abund–
dant in the northern waters of Newfoundland, and along the Labrador, particu–
larly in the southern part. In four seasons of collecting in Ungava Bay, the
present writer obtained only two specimens of Mallotus , and it is not known
to the present-day Eskimos of that region. Lucien Turner, however, visiting
Ungava Bay in the years 1882-84, records in his manuscript report (27) on the
fishes (never yet published; the auther is here indebted to the Smithsonian
Institution for the loan of the manuscript) that capelin had not been recorded
within Hudson Strait until several years previous to 1884 “when a few were
seen in the neighboring waters of George’s River.” Continuing the quotation
from the Turner manuscript: “In the spring of 1884 they were observed in
great numbers in that vicinity [George’s River, or, more properly, George
River]. On the 8th of August 1884 a school of several thousand individuals
appeared four miles within the mouth of the Koksoak River. As many as were
desired for specimens were secured by the hand as they swam near the shore….
This is the first instance known either to whites or natives of the appearance
of capelin in the southern portion of Ungava Bay. They are well known to the
Eskimo, who apply the name Kolelekuk to the caplin” (Turner 1885).
It is at once clear that faunal conditions in Ungava Bay in 1884 were
different from conditions in 1950. Capelin are now very rare, and they are
not known to the natives. They are North Atlantic fishes, edging into the
Subarctic, and they are seldom seen in swarms in water of temperature below
6°C. (25), although they have recently been observed in very large numbers

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

in 2°C. water in southeastern Newfoundland waters (Templeman, private
communication). At all events, the presence of capelin in large numbers
in Ungava in 1884 is a general indication of warmer conditions in the
water than exist at present. And yet, as has been recorded above, Turner
met with much more severe ice conditions in 1882 than are known today. It
is much to be deplored that routine temperature and salinity observations
were not kept at regular intervals in the eastern arctic of Canada in past
decades, because it is obvious that the history of hydrography and faunal
distribution in those waters has been varied, and the evidence brought
together here shows that the relations between atmospheric and marine
climate, and marine fauna, may not have been simple.

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

BIBLIOGRAPHY

1. Agapov, I.D., and Toporkov, G.N. “Some data concerning the fishes
of Novaya Zemlya.” Problems of the Arctic, vol.2, p.108.
Leningrad, 1937. (In Russian)

2. Ahlmann, H. “The present climate fluctuation.” Geogr.Jour ., CXII
(4-6), pp.165-193, 1949.

3. Anderson, R.M. “Catalogue of Canadian recent mammals.” Nat.Mus .
Canada., Bull . No.102, 1946.

4. ----. “Report on the natural history collections of the expedition,”
Stefansson’s My Life with the Eskimo , Macmillan, New York,
1913.

5. Bailey, W.B., and Hachey, H.B. “An increasing Atlantic influence in
Hudson Bay.” Joint Committee on Oceanography, St.Lawrence,
N.B. 11 pp. (mimeographed). 1949.

6. Dunbar, M.J. “Eastern Arctic Waters.” Fish.Res.Bd. Canada, Bull. No.88,
1951.

7. ----. “Marine macroplankton from the Canadian Eastern Arctic. II.
Medusae, et.” Can.J.Research , D, 20, pp.71-77, 1942.

8.----. “The state of the West Greenland current up to 1944.” Fish.Res.Bd .,
Canada, Jour . VI (7), pp.460-471, 1946.

9. Faester, K. “Effect of the climatic amelioration of the past decade on
the autumn change of coat of the arctic fox in Greenland.”
Medd.Grønl . vol.142 (2), 1945.

10. Griscom, L. The Birds of Concord . Cambridge, Mass., Harvard University
Press, 1949.

11. ---. Modern Bird Study . Cambridge Mass., Harvard University Press, 1945.

12. Hare, F.K. “The climate of the eastern arctic and subarctic of Canada
and its influence on accessibility.” Report for the Government
of Canada (Manuscript), 1950.

13. Helland-Hansen, B., and Nansen, F. “Temperature variations in the North
Atlantic Ocean and in the atmosphere.” Videnskapselskapets
Skrifter, I. , Mat.-Naturv. Klasse, 1916 (9).

14. Hubbs, C.L. “Changes in the fish fauna of western North America correlated
with changes in ocean temperature.” J.Mar.Res. , VII (3),
pp.459-480, 1949.

EA-Zoo. Dunbar: Faunistic Effects of Climatic Change

Bibliography

15. Jensen, Ad. S. “Concerning a change of climate during recent decades
in the arctic and subarctic…, etc.” Det.Kgl.Danske Vidensk .
Selsk., Biol Medd. , XIV (8), 1939.

16. Kiilerich, A.B. “The hydrography of the west Greenland fishing banks.”
Medd. fra Komm.Danm.Fisk. og Havunders. , Ser Hydrografi, 3 (3),
1943.

17. Kramp, P.L. “Medusae (Godthaab Expedition 1928).” Medd.Grøn ., vol.81
(1), 1942.

18. ----. “A revision of the Medusae belonging to the Family Mitrocomidae”
Vidensk. Medd.Dansk Naturh.Foren ., 92, pp.305-384, 1932.

19. Lauzier, L. “Unusually warm surface sea-water in 1949.” Fish.Res.Bd.
Canada, Progress Rep . Atlantic Coast Stations, No.51, p.17,
1950.

20. MacFarlane, R. “Notes on the mammals collected and observed in the
northern Mackenzie district, Northwest Territories.” Proc .
U.S. Nat.Mus., 28, pp.673-764, 1905.

21. Rand, A.L. “The mammals of northern Canada from a utilization viewpoint.”
Report for the Government of Canada. (Manuscript). I-XIV,
pp.1-809, 1949.

22. ----. “Northern records of the magpie, Pica pica hudsonia (Sabine).”
Can.Field-Nat ., 59 (1), p.45, 1945.

23. Soper, J.D. “The mammals of southern Baffin Island, Northwest Territories,
Canada.” J.Mamm. , 25 (3), pp.221-254, 1944.

24. Sutton, G.M., and Hamilton, W.J. “The mammals of Southampton Island.”
Mem. Carn.Mus., 12 (2), 1932.

25. Templeton, W. “The life history of the Chaplin ( Mallotus villosus O.F.
Müller) in Newfoundland waters.” Bull . Nfld.Govt.Lab.,
No.17 (Research), 1948.

26. Tully, J.P. “Seasonal cycles in the sea.” Fisheries Res.Bd. Canada,
Progress Rep . Pacific Coast Stations, No.85, pp.88-90, 1950.

27. Turner, L.M. “Fishes.” (Manuscript report deposited in the Smithsonian
Institution, Washington, D.C.), 1885.

Max M. J. Dunbar

Littoral Fauna of the Arctic

(EA-Zoo. Holger Madsen)

LITTORAL FAUNA OF THE ARCTIC

CONTENTS
Page
Introduction 1
Geographical Delimitation 3
Distribution of the High-Arctic and Subarctic
Zones in Different Regions
4
Shore Fauna of the High-Arctic Zone 9
Shore Fauna of the Subarctic Zone 14
Bibliography 16

EA-Zoology
(Holger Madsen)

LITTORAL FAUNA OF THE ARCTIC
Introduction
The shore falls into two more or less sharply delimited divisions: the
littoral and the supralittoral zones. The littoral is that portion which is
periodically inundated, i.e., the tidal zone; the supralittoral is that portion
above spring tidemarks, but affected by the sea. That part of the littoral
which is inundated only by spring tide is usually included with the supralittoral
zone under the name “upper beach,” while the area below is referred to, for con–
venience, as the “tidal zone” proper.
There is considerable variability in the extent of the two zones, depending
upon the slope of the shore, the height of the tidal wave, exposure to wind, etc.
Chiefly the depth of the zones is dependent upon the character of the coast,
whether rocky or sedimentary. In its strictest sense this delimitation applies
only to rock facies in absolutely wind-sheltered localities. Elsewhere , partly
due to waves, partly due to capillary attraction, on sandy shores, the littoral
area will shift upward. The downward shift of the boundary will be determined
by the lowest point to which the waves recede. A long period of calm weather
on an unsheltered shore may also force the line downward.
On the upper beach, terrestrial ecological conditions prevail, being modified,
however, by the influence of such marine factors as, for example, the salinity of

EA-Zoo. Madsen: Littoral Fauna

of the bordering sea. The upper beach is also delimited in respect to other
terrestrial biotopes by this and other marine factors. Where there is an afflux
of fresh water, conditions are modified in a limnological direction, even in
the tidal zone proper, brackish water or estuary conditions prevailing.
According to the aspect of the coast, the following biotopes in the tidal
zone can generally be discerned: ( 1 ) rock shore, ( 2 ) sand and/or gravel beach,
( 3 ) clay (or mud) shore, ( 4 ) mouth of stream or estuary, ( 5 ) littoral meadows,
and ( 6 ) lagoons. The last three mentioned biotopes vary greatly and are not
capable of sharp delimitation. Sand and clay shores present transitional stages,
as does a clay shore to estuary, littoral-meadow, and lagoon classification s .
Furthermore, only portions of the littoral meadows belong to the tidal zone proper,
the remainder belonging to the upper beach.
In regions with high tides, it is often possible to discern zones within the
above-mentioned biotopes. The interzonation becomes less apparent where arctic
conditions (in the broad sense of the term) predominate. Shore fauna all over the
world present interesting ecological features because of the varying conditions to
which they are submitted and the meeting of land and sea factors; but many special
phenomena occur in arctic shores, as might be expected from the more severe con–
ditions for life.
Comparatively little is known regarding the shore fauna of many arctic regions.
What knowledge we have is chiefly of Greenland, Spitsbergen, the Kola Peninsula,
and Novaya Zemlya. As to conditions on the arctic shores of America and Asia,
only scattered and casual information is available. From this, however, it is
possible to draw a few general conclusions, especially as to the biotopes of
rocky shores, which have been more thoroughly studied thus far. In such a habitat
the more conspicuous species occur, species which are commonly known and which

EA-Zoo. Madsen: Littoral Fauna

are liable to be collected even when expeditions lay scarcely any stress upon
zoological investigations. We have very few special investigations from which
to draw; for the most part our knowledge of littoral conditions must be compiled
from the general faunistical and zoogeographical papers that exist.
Geographical Delimitation
The geographical delimitation of the littoral zone, as shown by the actual
distribution of animals, coincides broadly with the ones used in other parts of
this Encyclopedia, but certain special features are apparent as regards the
tidal zone proper.
It is a common conception that the temperature and salinity of the water are
decisive factors for the littoral fauna; a conception supported by Steven (21)
and Dahl (5). As previously demonstrated by the author and strongly emphasized
by Dunbar (7), this does not, however, apply as to whether a specific littoral
fauna of higher animals, consisting of ( moll ) mollusks and Balanus balanoides ,
is actually able to develop in a given geographical region. The formation of
ice is almost wholly dependent on climate, and does not appear to be a decisive
factor. For example, a specific littoral fauna is present in Upernivik on the
northwest coast of Greenland but is absent in Scoresby Sound on the east coast;
yet the climate is practically the same in the two regions. Again, a sharp
climatic boundary is found about latitude 68°30′ N. in East Greenland, whereas
the boundary in the littoral is slightly north of 66° N. It seems, therefore,
that other causes are decisive here, causes which have some connection with the
sea and its abundance of life which would also affect the sublittoral fauna
(17; 19). According to Dunbar (7), the ocean currents are evidently a factor.
The arctic littoral clearly falls into two regions: a high-arctic and a
subarctic. The high-arctic region is distinguished by the lack of a number of

EA-Zoo. Madsen: Littoral Fauna

forms characteristic of the littoral in other latitudes, notably the Balanus
balanoides
and other barnacles, mollusks, and the Hydroida Hydroida .
We have thus good criteria for delimitation of the arctic and subarctic
littoral regions. The southern delimitation of the Subarctic is more difficult.
There are, however, certain species of high-arctic distribution which are also found
in subarctic areas, and which may be taken as good indicators of the presence of
an admixture of polar water. The southern limit of their distribution may thus
be taken as a good guide to the limit of their subarctic region. Such species are
the amphipod Pseudalibrotus littoralis and the mysid Mysis oculata . It is of
interest to note that P. littoralis , within the subarctic area, is usually con–
fined to estuaries.
So great are the differences met with in the subarctic zone that a more
detailed geographical subdivision is needed; and it may be predicted that one
will be made when more accurate information is available. But from the studies
thus far made it becomes obvious that the boundaries of the two zones are not
due to any single factor, such as differences in temperature, salinity, etc.,
but rather to a combination of factors not least of which are the ocean currents.
The high-arctic region is exclusively under the influence of arctic waters, but
the subarctic has everywhere a connection with warmer waters through the ocean
currents. Thus, the boundaries will shift in accordance with the fluctuations
of these currents (15).
Distribution of the High-Arctic and Subarctic Zones
in Different Regions
In Greenland, curiously enough, the longest stretch of the coast is subarctic
in character. Conditions on the north coast have not been investigate s d , but from
what is known about the nature of this region it is assumed to be high-arctic.

EA-Zoo. Madsen: Littoral Fauna

The east coast, which has been investigated, is high-arctic down to a point
immediately north of Angmagssalik, about 66° N. latitude, the northernmost
limits for the snail Littorina saxatilis var. groenlandica, the mussel
Mytilus edulis , the barnacle Balanus balanoides , the amphipod Jaera marina ,
and the polychaete Arenicola marina .
From that point southward, the east coast is subarctic. The entire west
coast is subarctic northward to the Thule District (about 76° N.), although
very great differences are to be found on this enormous stretch. In previous
u: OIC? papers the author regarded the Thule District as high-arctic since the presence
of Mytilus edulis , although probable, judging from statements made by Greenlanders,
had not been proved. Recently, however, Vibe (verbal communication) found this
species in large numbers up to the lowest horizon of the tidal zone in several
Thule localities. Previously the author was inclined to reckon regions as
being in the high-arctic zone where Mytilus , and this species only of the higher
littoral forms, occurs in the sublittoral (as it is also reported from Novaya
Zemlya). But now it would seem that the very occurrence of this species indicates
an influence of Atlantic water (see also (7)).
Since no mollusks other than Mytilus occur in the tidal zone farther north,
the Thule District can be regarded as the northernmost outpost of the subarctic
fauna. But in fact we must descend the coast for quite a distance southward
(about 73° N.) to find similar conditions, for it is at that latitude that the
L o i ttorina saxatilis var. groenlandica makes its first appearance. Still farther
southward, at Upernivik (72°47′ N.), a rather rich littoral fauna is met with.
There, besides the already mentioned forms, especially the littoral hydroids,
are found the u: previously called amphipod. Which is correct isopod Jaera marina , tubificides, and a number of mollusks and
polychaetes, which also occur in the sublittoral. Balanus balanoides was not found
in 1936, when the investigations were made.

EA-Zoo. Madsen: Littoral Fauna

In spite of zealous search, only older specimens of Mytilus edulis were
found at Upernivik and in the Thule District. From this fact it was concluded
that M. edulis does not spawn every year. It is possible, however, that they do
spawn but that the spat is unable to survive. Judging from the furrows in the
shell, some of the specimens are very old, probably twenty years.
A little farther southward (72°23′ N.) in the harbor of Prőven, Balanus
balanoides makes its appearance, though few in number and restricted, especially
by the strong prevailing current of the locality, as to areas which enjoy favorable
conditions. At exactly what point southward continuous populations of B. balanoides
occur is not known.
In the Umanak District the fauna has a more distinctly boreal stamp in places
where the freshwater influence, due to the outflow of glaciers, is not too marked,
as was shown by the investigations of Vanhőffen (31). Arenicola marina occurs here.
Moving southward along the coast, the fauna is of the same main composition,
though more numerous and varied. Special littoral investigations of Amerdlok Fjord
in the Holsteinsborg District (about 67° N.) disclose the presence of a very rich
fauna, notably on the clay shore, where are Mytilus beds comparable in weight per
square meter to those of boreal waters (21).
Aside from those mentioned, no other special littoral investigations have
been made. But much information can be gleaned from Otto Fabricius’ Fauna
Groenlandica (1780) as to the littoral fauna in the Frederikshaab District (16).
Fabricus’ investigations disclose the presence of a very rich littoral fauna as
well as a large number of sublittoral species. The only characteristically arctic
form present here is the Pseudalibrotus littoralis which, at this more southern
latitude, is retricted to river mouths.
The fauna of north and east Iceland resembles that on the southwest coast
of Greenland.

EA-Zoo. Madsen: Littoral Fauna

Very little is known about the littoral fauna of Jan Mayen. Becker, in 1886,
mentioned Littorina palliata but once, and then as occurring in one locality
only, a cave on the island (which reference needs to be confirmed). The presence
in the supralittoral of the boreal fly Fucellia fucorum (14), would also seem to
indicate boreal influence (14), as do certain features of the fish fauna (15).
On the whole, however, the fauna is for the most part arctic in character, so
that Jan Mayen may be regarded as a subarctic outpost.
In the southwestern part of Spitsbergen (Svalbard), subarctic conditions
prevail. Here we find Littorina sax a t a i lis var. groenlandica , Balanus balanoides ,
some hydroids, and bryozoans. Mytilus edulis no longer exists in Spitsbergen,
although subfossils from postglacial times have been found. Probably, because of
its comparatively short-lived larval stage, it has not since been able to spread
again to this region author OK? (26). In this connection, it can be mentioned that the
snails, Skeneopsis planorbis and Littorina littorea , referred to, respectively,
by Thiele (23) and Elton and Baden-Powell (8), have not been found in Spitsbergen
(compare (18) and (24). The occurrence of the beetle Micralymma marinum indicates
the arctic influence on the southern fauna here, as well as in Bear Island to the
south of Spitsbergen. On Bear Island, Balanus balanoides are also met with in
large numbers (30). Too little is known of the fauna of Spitsbergen to warrant
drawing distinct boundaries, but the northern parts are probably high-arctic.
In all probability the same hol e d s true for Franz Josef Land. At any rate, none
of the special littoral mollusks has been reported from there.
On the A rc sia tic-European continent, the southern limit of the subarctic may be
drawn at Lofoten in Norway, since this point seems to be the southernmost limit
for the arctic Pseudalibrotus littoralis as well as the northernmost limit for
several littoral forms such as the snail Patella vulgate (6) (see (6) , especially

EA-Zoo. Madsen: Littoral Fauna

1934-37). The eastern boundary of the subarctic littoral is near the entrance
to the Kara Sea, conditions in this area greatly resembling those of northwest
Greenland; Littorina saxatilis occurs along a wide stretch, Balanus balanoides
more locally. However, several authors mention the occasional occurrence s of
young B. balanoides right into the Kara Sea, borne there probably by the constant
eastward current through Yugorski Shar. The greater part of the Kara Sea may be
classified as high-arctic.
The greater part of Novaya Zemlya also belongs to the arctic province, but
in the southern part the Atlantic influence is felt, as apparent in the occurrence
of Mytilus edulis , which for the most part lives sublittorally, as in the Thule
District in northwest Greenland. Other manifestations of the Atlantic influence
are the presence of Littorina palliate (24) and the occasional occurrence of
Balanus balanoides in Matochkin Shar (22).
High-arctic conditions prevail along the Siberian coast; Pseudalibrotus
littoralis, however, is replaced by the Siberian species, P. birulai . In the
Chukotsk Sea, east of Wrangel Island, subarctic conditions return, that is,
Pacific influence reaches that far west (22). It is difficult to designate
exactly the southern boundary of the subarctic on the western side of Bering
Strait; out two “indicators,” P. littoralis and Mysis oculata , do not occur
south of St. Lawrence Island, but there is evidence, nevertheless, for arctic
influence somewhat farther south. The level of Lorenz Island is the limit of the
subarctic on the eastern side of Bering Strait, but some arctic influence is felt
a little farther south on the western side, in the sublittoral (3; 10).
The whole northern coast of the American continent is undoubtedly subarctic,
but very little is known about the fauna of this region, and conditions on the
northern islands are quite unknown. The entire eastern coast of Baffin Island

EA-Zoo. Madsen: Littoral Fauna

is subarctic, Mytilus having been found at Pond Inlet (17) and Balanus balanoides
has been found near Cumberland sound (22). What conditions prevail on Ellesmere
Island is now known, but it can be hazarded that the arctic zone descends some–
what farther southward on the western side of Baffin Bay. As to Pseudalibrotus
littoralis on the eastern coast of America, nothing is known; but the southern
limit of Mysis oculata is at Cape Charles, Labrador (about 53° N.). The occur–
rence of Littorina palliata would also indicate the subarctic character of the
region (20). We must, however, remember that this species seems to extend
farther south in America than in Europe the Iceland (24).
Knowledge of the supralittoral is still more restricted than that of the
littoral zone proper. The limits will be seen to follow different courses,
corresponding more closely to the climatic limits, these in turn being affected
by ocean currents. Roughly, it may be said that the upper beach fauna in the
subarctic region will prove to be rather poor. The Orchestia community seems to
appear nowhere, are judging from the work in northern U.S.S.R. , littoral beetles,
with the exception of certain species of Micralymma , extend but a little distance
into the subarctic. Dispersion-ecological causes may account for the absence of
a number of littoral Hydrophlidae and Staphylinidae which are common in northern
Iceland, subarctic Greenland, Spitsbergen, and Novaya Zemlya.
Shore Fauna of the High-Arctic Zone
Even though animals prevalent in the subarctic regions, such as mollusks,
barnacles, and hydroids, are completely absent in the high-arctic zone, other
animals adapted to the special shore conditions may be found. These special
shore conditions have been specifically investigated in East Greenland only,
but it is thought that similar conditions prevail throughout the high-arctic zone.

EA-Zoo. Madsen: Littoral Fauna

The main characteristic of the fauna is that, the more severe the conditions
the fewer the animals, both as to species and specimens. Very few examples of
true arctic animals adapted to life on the shore are known. The only instances
of which we can be sure are found among the order Diptera: the Muscidae Fucella
arciiformis and F. pictipennis, and the Chironomidae, Orthocladius decoratus ,
O. groenlandensis , O. fusistylis , and Smittia extrema . These live on the upper
beach as adults, in lagoons and littoral meadows as larvae, as do related species
in boreal regions.
Since the distribution of these animals is much more dependent upon climatic
than upon littoral conditions, and distribution will not follow the littoral
boundaries outlined above. However, it may be said that they have a pronounced
northern distribution. Fucellia apparently has a western distribution, having
been reported only in Greenland and Arctic America, whereas Orthocladius decoratus
and Smittia extrema apparently have a more eastern distribution, being known to
occur in Spitsbergen. The staphylinid beetle Micralymma brevilingue , a few larvae
of which have been found in lagoons in East Greenland, and M. dicksoni , of similar
habits and occurring in northern Siberia, should also be mentioned.
On sand shore and in sand patches on gravel shore in the tidal zone proper,
the turbellarians Notocaryoplana arctic a have been found, as have been, on clay
shore, Protomascrostomum groenlandicum . Both are new genera and species to the
author’s material from East Greenland and may prove to be true arctic shore
animals. As already stated, Pseudalibrotus littoralis is of wide arctic dis–
tribution, being related to the shore but not exclusively bound to it and,
though its habitats differ in the high-arctic and subarctic, occurs in both.
The phenomenon noted in the distribution of Pseudalibrotus littoralis,
namely, that the habitat is less restricted in the high-arctic than in more

EA-Zoo. Madsen: Littoral Fauna

southern regions, is one frequently noted in the high-arctic, and may be due to
differences in competitive conditions.
Aside from the above-mentioned species, a few other animals occur, also
being shore forms in the subarctic and boreal regions, again illustrating the
notably thinned-out character of high-arctic fauna. Wherever sufficient moisture
is present, enchytraeids occur, especially Lumbricillus lineatus in Greenland
(but doubtless elsewhere as well), Enchytraeus albidus , and probably other species,
if Spitsbergen, which has been especially well investigated in this respect, may
be taken as typical. The orybatid Ameronothrus lineatus very frequently occurs,
most often in the variety nigrofemoratus . The various biotopes occur in differing
frequencies, salt marshes harboring an especially rich fauna.
Other true littoral animals occur: the collemboles, Archisotoma besselsi and
Hypogastrura viatica , and the parasitoid, Molgus littoralis .
On rock shore the animal life is very poor, Molgus littoralis from the upper
beach alone being know n , but it probably feeds on some small as yet unknown
animals of the littoral lichen zone.
In the shor e t , tomentose, algal vegetation within the tidal zone proper,
Ameronothrus occur, in association with oligochaetes, and undoubtedly also small
crustaceans, including several copepoda, which have also been ob served on other facies.
In most high-arctic regions this vegetation is characterized by the absence of
the dominant littoral algae, Fucus vesiculosus and Ascophyllum nodosum . Further,
several amphipods can be found, of which Gammarus locusta setosus Is this correct? has been
observed as especially common. No investigations on rock pools have as yet been
made, but in all probability their fauna will show similarities to that of the
lagoons. A striking feature of the rock-shore fauna is that it is not restricted
to rock shore, all the species having also been found on other types of shore.

EA-Zoo. Madsen: Littoral Fauna

The sediment facies is of course as differentiated as in other regions, but,
in contradistinction to more southern regions, no gr an ea t differences in the compo–
sition of the fauna can be observed. The plant life is of but slight importance,
and the animal life of no importance.
On the upper beach, the above-mentioned flies and chironomides occur, together
with the littoral collemboles and mites, a large number of other collemboles (12),
and several spiders, the most common of these being Micryphantes nigripes and
species of Erigone Erigone (2), buried among the washed-up algae in the drift line.
Oligochaetes are also found.
In the tidal zone proper, on gravel and sand beach, we find Gammarus locusta
setosus , Pseudalibrotus littoralis (the latter burrowing in the sand), and along
with the oligochaetes, the turbellarians, Notocaryoplana arctica and Monocelis fusca ,
these last two being absent where strong freshwater influence prevails and, finally,
several harpacticoids, these being known as brackish-water forms.
Clay (or mud) shore has been studied in one locality only. There the forma–
tion was dependent on the outflow of a glacier, and it presented, on the whole,
the same picture as to fauna as had been found on sand shore, with a few exceptions.
The exceptions were the presence of a special turbellarian, Protomacrostomum
groenlandicum , not specifically determined ostracodes, and the harpacticoid
Bradya typica , which is always associated with a clay bottom. In stream mouths,
where extensive flats are often formed, and in lagoons, the usual animals may be
found. In stream mouths they are rather scattered. Here, the larvae of the
shore flies and midges, which occur characteristically in sheltered places, are
apparently coincident with accumulated organic matter, just as on the upper beach
animals occur only where vegetation is present. In the water of the stream mouths
and lagoons, Laophomte strőmi and species of Tachidius live, these harpacticoids

EA-Zoo. Madsen: Littoral Fauna

being known as brackish-water forms. The young of Cottus quadricornis prefer to
live in these places as well. Here, the small fishes are hunted by gulls, the
smallest animals being also preyed upon by small waders, although these birds
do not, as in boreal regions, nest on the shore. Geese crop close the vegeta–
tion of the littoral meadows which are characteristically covered with a mixture
of the algae Puccinellia phryganodes and Carex ursina .
In the soil there is a teeming life of orybatids and collemboles and, where
there is a great deal of moisture, myriads of oligochaetes, nematodes, and pro–
tozoans, often rotifers and tardigrades as well, this latter life being especially
intensified in the film of cyanophyceans and diatoms occurring in the tidal part
of the lagoons and littoral meadows. Spiders abound in the upper beaches.
The afflux of fresh water is the most important factor modifying conditions
of life in the salt marshes, the richest development of animal life occurring
where such an influence is felt. But, although the animals may be numerically
very considerable ( Ameronothrus up to about 50,000 per square meter, oligochaetes
and chironomides larvae about 12,600), the weights, which never exceed 20 grams,
are negligible compared with those of the marine communities.
It is an interesting fact that in the arctic zones, particularly in the
high-arctic, plants and animals are not so strictly bound to the shore as in
more southern regions. This is especially noticeable in places where, from some
dispersion-ecological causes, fewer species are present. Molgus littoralis can
be found rather far from shore (16), as is true of the same species and Bdella
decipiens in northern Spitsbergen (27; 29). A number of shore plants, too, are
sometimes found far from shore, in places manured by birds or human beings, for
example, in the ruins of Eskimo houses. The spider Ameronothrus lineatus has
been found on bird cliffs on Bear Island and Ameronothrus and the shore oligochaete

EA-Zoo. Madsen: Littoral Fauna

Lumbri o ci llus profugus have occurred in mosses on Jan Mayen (4; 28). Again, a
number of animals found in the tidal zone farther south tend to be found lower
down (in the sublittoral) in arctic conditions, and this tendency becomes more
marked the more completely arctic the climate. This is found also, oddly enough,
in the Baltic, where, for instance, several littoral mollusks occur in much
deeper water than elsewhere (11; 17). It is possible that in this case also
the diminished competition due to the smaller number of species may be an impor–
tant factor.
Shore Fauna of the Subarctic Zone
As already stated, a great variety of fauna can be found within this zone.
In fact, in its more southern portions or where conditions are for some reason
particularly favorable, a fauna as rich as or even richer than that of many
boreal regions occurs. A number of special investigations have been made, notably
along the Murman coast (11) and in West Greenland (18 ref. right? ; 21). The presence of Mysis
oculata , which is found almost everywhere, and the occurrence of Pseudalibrotus
littoralis as an estuarine form are outstanding characteristics of this zone.
The arctic influence on the fauna is felt in the absence of a number of boreal
forms. This is particularly true of the fauna of islands, such as Iceland, where
more special conditions prevail.
Where the fauna is submitted to the influence of freshwater factors (rivers
and glaciers), a deterioration takes place. But where pure marine conditions
are provided, we find a teeming life in the littoral.
On rock shore, the Balanus balanoides and Mytilus edulis associations dominate,
but there is a great variety of other mollusks and also crustaceans and worms,
these latter partly in connection with a strong vegetation of higher algae. On
beaches with sand and gravel, there is a rich life of burrowing worms and mussels.

EA-Zoo. Madsen: Littoral Fauna

On clay shore a still more luxurious life occurs, with a greater number of
individuals and the specimens being also of larger size. As in boreal regions,
the clay shore frequently develops into regular beds of Mytilus , many of the
specimens being as large as those found in boreal regions. There is a rich
epifauna of the same character as that found on the rock shore. Communities
of Macoma balthica-Arenicola marina abound, as do communities of Pygospio elegans ,
the latter occurring in river mouths as in boreal regions. A Hydrobia ulvae
community occurs on the Murman coast, but is missing both in Iceland and Greenland,
probably for reasons of dispersal. A Corophium volutator community seems to be
missing everywhere.
On the upper beach, where climatic conditions make themselves most clearly
felt, the arctic influence on the fauna is very apparent, asserting itself
characteristically, as mentioned above, in the total absence of an Orchestia
community. In many places shore beetles abound. Backlund (1) has recently
contributed to our knowledge of these littoral beetles by making collections in
the Petsamo district of northern Finland.

EA-Zoo. Madsen: Littoral Fauna

BIBLIOGRAPHY

1. Backlund, H.O. “Wrack fauna of Sweden and Finland, ecology and chorology,”
Opusc.Entom . Suppl. 1945.

2. Braendegaard, J. “The spiders (Araneina) of East Greenland. A faunistic
and zoogeographical investifation,” Medd.Grøenland, vol.121,
no.15, 1946.

3. Broch, Hj. “Noen dyregeografiske trekk i nordhavenes bunndyrverden,”
Norsk. Geogr.Tidsskr . vol . 6, no.6, pp.1-16, 1937.

4. C Č ernosvitov, L. “Sur quelques oligoch e è tes de la r e é gion arcti c que et des
I Î les Faer-Oer,” Annalses Sci.Nat. vol. Ser. 10, no. vol. 14, pp.65-111, 1931.

5. Dahl, E. “On the s S maller a A rthropoda of m M arine a A lgae, e E specially in the On the s S maller a A rthropoda of m M arine a A lgae, e E specially in the
p P olyhaline w W aters off the Swedish West c C oast,” p P olyhaline w W aters off the Swedish West c C oast,” Lund, Gleerup, 1948. Undersőkningar över
Oresund , vol.35 . 1948. (Gleerup, Lund, Sweden,)

6. Dons, C. “Norges strandfauna, I-XIX,” Norske Videnskaps-Akad. Forh.
vol.5, no.50; vol.6, no.11, 24; vol.7, no.2, 25, 30; vol.8, no.9.
12,20,21; vol.9, no.20,42,43; vol.10, no.8, 9, 12, 13, 14, 1932-37.

7. Dunbar, M.J. “Note on the delimitation of the arctic and subarctic zones,”
Canad.Field Nat. vol.61, no.1, pp.12-14, 1947.

8. Elton, C.S., and Baden-Powell, D.F.W. “On a collection of raised beach
fossils from Spitzbergen,” Geol.Mag . Lond. Vol.68, pp.385-405, 1931.

9. Gisl e é n, Torsten. “Epibioses of the Gullmar Fjord. I. & II,” Kristinebergs
Zool.Stat. 1877-1927. Papers no.3,4, 1930. (Svenska Vetenskapsakad.
Skriftseries .)

10. Gurianova, E. “Beiträge zur Kenntnis der Isopodenfauna des Pazifischen
Ozeans IV,” Zoologischer Anz . Vol.114, pp.250-65, 1936.

11. ----, Saks, I., and Ushakov, P. “Litoral Zapadnogo Murmana.”
(The littoral of West Murman.), Leningrad. Gosudarstvennyi Gidrol.
Inst. Issled.Morei SSSR, vol.11 , pp.47-104, 1930.

12. Hammer, M. “Studies on the Oribatides and Collemboles of Greenland,”
Medd. Grønland vol.141, no.3, 1944.

13. Henriksen, K.L. “A revised index of the insects of Grønland,” Ibid . vol.119,
no.10. 193 0 9 .

EA-Zoo. Madsen: Littoral Fauna. Bibliogrpahy

14. ----, and Lundbeck, Will. “Landarthropoder (Insecta et Arachnida),”
Ibid . vol.22, pp.481-823, 1917.

15. Jensen, Ad.S. “Concerning a change of climate during recent decades
in the arctic and subarctic regions, from Greenland in the west
to Eurasia in the east, and contemporary biological and
geophysical changes,” Danske Vidensk.Selsk. Biologiske Medd .
vol.14, no.8, pp.1-75, 1939.

16. Madsen, Holger. “Biology of a littoral mite,” Nature , Lond. Vol.139,
no.3521, p. 715, 1937.

17. ----. “Investigations on the shore fauna of East Greenland with a
survey of the shores of other arctic regions,” Medd.Grønland
vol.100, no.8, 1936.

18. ----. “Some zoogeographical corrections,” J.Conch . vol.21, pp.9-10, 1938.

19. ----. “A study of the littoral fauna of Northwest Greenland,” Medd.Grønland
vol.124, no.3, 1940.

20. Packard , A.S. “On the recent invertebrate fauna of Labrador,” Boston
Soc.Nat.Hist. Mem . vol.1, 1865.

21. Steven, D. “The shore fauna of Amerdloq fjord, West Greenland,”
J.Animal Ecol . vol.7, pp.53-70, 1938.

22. Tarasov, N.L. “K faune usonogikh rakov ( Cirripedia thoracica ) Severnogo
Ledovitogo Okeana. III.” (Contribution to the fauna of
Cirripedia thoracica of the Arctic Ocean. III.), Leningrad.
Arkticheskii M N auchn-Issled.Inst. Trudy vol.50, pp.35-59, 1937.

23. Thiele, J. “Arktische Loricaten, Gastropoden, Scaphopoden und Bivalven,”
Fauna Arct . vol.5, pt.2, 1928.

24. Thorson, G. “Marine Gastropoda Prosobranchiata,” Zool. Iceland vol.4,
no pt. 60, pp.1- 149 150 , 1941.

25. ----. “Marine Gastropoda Prosebranchiata. Zool. East Greenland,”
Medd.Grønland vol.121, no.13, 1944.

26. ----. “Reproduction and larval development of Danish marine bottom
invertebrates, with special reference to the plan e c tonic larvae
in the Sound (Øresund),” Denmark. Komm.for Fisk.-og Havunders.
Medd.Ser.Plankton vol.4, no.1, 1946.

27. Trägårdh, J. “Acari,” Medd.Grønland vol.43, no.14, 1917.

28. ----. “Monographie der arktischen Acariden,” Fauna Arct . vol.4, no.1, 1904.

EA-Zoo. Madsen: Littoral Fauna. Bibliography

29. ----. “Zur Kenntnis der litoralen Arten der Gattung Bdella Latr . ,
Svenska Vetenskapsakad. Bihang Handl . vol.27, no.4, p.9, 1902.

Arther 30. Urban, W. d’. “Zoology of Barents Sea,” Annals & Mag.Nat.Hist . vol.5,
no.6, 1880.

31. Vanhöffen, E. “Die Fauna und Flora Grønlands,” Drygalski, Erich von. Grønland - Expedition der Grønland - Expedition der
Gesellschaft fűr Erdkunde zu Berlin 1891-1893 Gesellschaft f ű r Erdkunde zu Berlin 1891-1893 . Berlin, Kűhl, 1897. vol.2.

Holger Madsen

Benthonic Fauna of the Arctic and Subarctic Seas

EA-Zoology (Hjalmar Broch)

BENTHONIC FAUNA OF THE ARCTIC AND SUBARCTIC SEAS

This manuscript was accompanied by 11 maps. Because of the high price
of reproducing such maps, only a few submitted will be used in Encyclopedia
Arctica . The selection of the number of these maps will be determined by
the publisher, and the choice of those used should be made in conjunction
with a representative of the publisher. All maps are, therefore, being held
at the Stefansson Library until a selection can be made.

EA-Zoology
(Hjalmar Broch)

BENTHONIC FAUNA OF THE ARCTIC AND SUBARCTIC SEAS
A cursory review of the benthonic or sea-bottom animal world of the arctic
seas reveals some conflicting features. By comparison with the numbers of species
in temperate seas, the fauna must be character ia z ted as poor. This puts a stamp
of uniformity on the fauna which is further emphasized by the richness in individual
specimens. For, though the species are few, the number of individuals is, in
most cases, comparatively large. The zoologist is, therefore, inclined to charac–
terize the fauna as rather uniform or poor, whereas from the point of view of the
abundance of individuals it may be said to be rich.
Although ecologists generally maintain that the number of individuals is
large in the arctic seas, where conditions are apparently unfavorable to the
existence of many species, our recent investigations make it by no means easy to
arrive at an explanation. The cause may be found in the obvious tendency of
arctic animals to shorten their larval, planktonic or passively floating period
of life, and to extend the nektonic or actively swimming life. These tendencies
are common to the benthonic fauna of the Arctic as well as Antarctic, which leads
to the supposition that the phenomenon must somehow be correlated with low
temperatures.
Ecological investigations in Greenland waters, more especially by Gunnar
Thorsen, have to a certain extent thrown light upon the question. Since the

EA-Zoo. Broch: Benthonic Fauna

phytoplankton has but a short period of abundance in the icy seas and since the
sea fauna depends upon it for nourishment, the larval development must be finished
during these short periods of abundance. Either this or the further development
of the animal must proceed in the body cav o i ties of the adult. The theory is
plausible; but it scarcely explains the numerical abundance of individuals in
every species and in most localities, such abundance not being apparently con–
sistent with recurrent seasonal scarcity of food.
No adequate reason has as yet been found to explain why the arctic benthonic
fauna shows this tendency to develop great numbers of individuals and their
apparent gregariousness. As an example of such tendencies, 2,000 specimens of
the brittle star, Ophiura nodosa , have been taken at one station in the Kara Sea.
Similarly, more than 400 specimens of the large crab, Chionectes opilio , have
been taken in single hauls in eastern Siberian waters and more than 1,000 specimens
of the cumacean crusteacean, Diastylis sp., in one catch with a dredge by the Vega
expedition working in the same sea. In the Barents Sea, the Norwegian steamer
Michael Sars, Michael Sars, in 1902, caught in a trawl more than one ton e of sponges, Geodia sp.,
and on another occasion, near Jan Mayen, more than a barrelful of the small mussel Pecton
groenlandica
. Ossian Sars reports from the Norwegian North Atlantic Expedition
that the trawl near Spitsbergen came up positively filled with the sea lily
Antedon eschrichti . Many more such hauls have been reported.
Such occurrences seem to be more frequent in eastern Siberian waters than in
the Kara Sea and farther westward. Data concerning such phenomena in arctic
American waters are as yet lacking. It must be noted, too, that, due probably
to the limitations and selective nature of the methods employed, the data on
bottom samplings by Russian zoologists make no mention of such gregarious
tendencies in arctic waters investigated by them. Moreover, a complete evaluation

EA-Zoo. Broch: Benthonic Fauna

of animal life cannot be made on the basis of bottom samplings, since vagile
benthonic animals almost entirely escape and thus elude investigation.
As with other individuals among arctic animals, which are larger than in
temperate regions, the benthonic fauna of the Arctic shows a vigorous develop–
ment as to size. On the other hand, recent investigations have revealed a
slower rate of growth in arctic animals. The potency of growth being, however,
independent of its swiftness, this does not involve a contradiction. In graphic
terms, we may describe growth as proceeding along an ascending curve, the rise
being less steep the lower the temperature. The metabolism, however, increases
almost parallel with the surface of the individual, proceeding, as another potential
curve, more steeply with increased temperatures. The final size of the individual
is reached when the two curves cross (where the metabolism equals the potency of
growth). This point will be reached at smaller size under higher temperatures,
the growth continuing at lower temperatures - provided there is no interference
from accidental factors such as lack of food, variations in salinity, etc.
The inference may justifiably be drawn that benthonic animals of the Arctic
are longer lived than are those of temperate or tropical waters. In other words,
we may hazard the statement that the total metabolism of the fauna of arctic seas
is rather strongly retarded and that the causal factor is the prevalence of low
temperatures.
A vertical or bathymetric study of ar t c tic waters shows less stratification
in clearly separated layers than is the case with marine life in temperate or
tropical regions. In warmer seas three bathymetric zones can generally be clearly
distinguished: ( 1 ) an upper region of the costal banks (the continental shelf),
with a depth of some 400 to 600 meters; ( 2 ) an intermediate or archibenthal region,
with a depth of about 1,500 or 2,000 meters; and, ( 3 ) farthest down, the abyssal

EA-Zoo. Broch: Benthonic Fauna

region. Recent investigations have shown that, in arctic waters, the two deeper
levels are more confluent faunistically than elsewhere, although the special
facies (ooze) of the greatest depths still act selectively upon the animal world.
Species, for instance, which occur mainly along the slopes of the central arctic
basin are often met with in the deeper and icy cold strata of the Norwegian Sea,
and typical s e pecies from the abyssal depths of that sea are often, in higher
latitudes, found more or less accidentally in rather shallow water, even in the
shelf sea. Nevertheless, it is convenient to treat the deep sea and the shelf
sea (the sea along the coastal banks) separately. We shall begin with the deeper
waters where the fauna is comparatively poor.
A glance at the charts of the northern seas reveals that the deep sea of
the Arctic ( below a 600-meter depth) falls into three sections. The great central
polar deep surrounding the North Pole communicates with the deep of the Norwegian
sea, traversing the Nansen Ridge between Spitsbergen and North Greenland, the
shallowest part of the ridge being situated some 1,000 meters below the level of
the sea. The icy cold depths of the Norwegian Sea are thus, as it were, an inte–
gral part of the arctic deep sea, though separated from the warmer Atlantic deep
sea by the shallow ridge in the Faeroe Channel, which is only about 600 meters
below sea level. To the south, this deep borders the Atlantic deep waters in
Davis Strait, elsewhere is separated from the polar deep by the shallow sounds
between the arctic islands and Greenland. Finally, the deepest parts of the Okhotsk
Sea form a basin effectively isolated from the polar deep, although these portions
must be ranged for study with the arctic deep waters.
Our knowledge of the deepest parts of the central polar deep is very limited.
This is partly because of the difficulties of operating dredging gears from ice
surfaces and partly because so few expeditions equipped for deep-sea investigation

EA-Zoo. Broch: Benthonic Fauna

have crossed it. The Russians have occasionally collected specimens in the
deep sea along the Siberian slopes; but in many cases their publications are
not readily accessible. Largely because of the impracticability of carrying
out deep-sea work along the North American arctic coasts, very little is known
as to the benthonic fauna of these regions. Nevertheless, from the scattered
and inadequate information available to us, we can draw a few general conclusions.
The data obtained by the expeditions which have worked along the Nansen Ridge and
north of Spitsbergen prove the uniform character of the fauna in the deeps of the
Norwegian Sea and of the central polar basin.
On the whole, the productivity of the lowest depths (2,000 meters and more)
is slight. The ocean bottom being always covered with Globigerina or Biloculina
ooze, the only attached animals that can exist there are those that have developed
special “root systems” which enable them to fix themselves in the soft bottom
without being drowned in the mud. An example of such adaptation is the Ilycrinus
carpenteri , a sea lily which is common to and characteristic of the arctic
abyssal deep. The sea slugs Kolga hyalina and Elpidia glacialis are also found,
the latter being met with in shallower depths at higher latitudes and occasionally
even in the deepest part of the coastal banks. Also found in the greatest depths
of the central Arctic Sea are the following: an isopod crustacean, Mesidothea
megalura ; the amphipod crustaceans, Bruzelia dentata and Harpinia abyssi ; the
mysidaceans, Pseudomysis abyssi (the only species known of this genus) and
Boreomysis scyphops ; the blind prawn, Bythocaris leucopis , and its near relation
B. payeri , the latter species also ascending to somewhat shallower parts of the
ocean deeps.
In the abyssal regions below 1 , 000 meters, the lamellibranchiate, Peston
frigidus , is perhaps the most common and characteristic. At the same depth occur

EA-Zoo. Broch: Benthonic Fauna

marine snails, Neptunea mohni , Natica bathybii , and Bella ovalis . One of the
most interesting of the benthonic fauna of these icy depths is the red liparid
fish, Rhodichthys regina , which has not as yet been found in depths of less
tham 1,150 meters.
It is interesting to try to trace the origin of the arctic abyssal fauna
by looking for related species in other oceans. Thus far such speculations have
been inconclusive, but certain interesting facts do emerge. For instance, the
genus Ilycrinus is restricted to the Pacific-Antarctic regions, whereas the
genus Bruzelia , though apparently it does not occur in the Pacific, has been
found outside the Arctic in shallower North Atlantic waters. The Harpinia abyssi
and the Bythocaris pa p y eri are among the rare abyssal arctic fauna which are
occasionally met with in the Atlantic deeps bordering the Arctic. On the other
hand, the genus Mesidothea , of which there are but four known species, is
entirely restricted to the arctic region and it may, therefore, be concluded that
it originated there. Apparently, then, the benthonic arctic fauna may have been
in part recruited from neighboring Atlantic and Pacific waters, but it also in–
cludes many species indigenous to the Arctic.
The upper portions of the arctic deep sea, known as the archibenthal or
intermediate region, has a richer and more varied fauna, not counting the
occasional visitors from shallower waters. The reason for this is the more
varied bottom facies encountered above the “mud line.” The zone, however, cannot
be clearly delimited. Some species, such as the above-mentioned sea slug- Elpidia
glacialis , are found to be, especially in higher latitudes, very common in the
upper layers of the deep sea, whenever the special facies (soft, muddy bottom)
exists, and other species, such as the sea star Tylaster willei , are found at
such varying depths that we cannot determine with any certainty at what depth

EA-Zoo. Broch: Benthonic Fauna

to assign them as characteristic. A third echinoderm, the feather star Poliometra
prolixa
, decidedly belongs to the upper part of the deep-sea region, but speci–
mens of it have been rather frequently met with in abyssal depths and in the
deeper portions of the “shelf” sea. The only seas urchin endemic to the arctic
deep sea, Pourtalesia jeffreysi , is similarly found occasionally in other zones
of the Arctic. The squid, Cirroteuthis mulleri , unique in this among its kind,
is always found at depths ranging from 550 to 2,300 meters and at temperatures
below 0°C. Among the crustaceans, the mysids, Parerythrops spectabilis and
Erythrops glacialis, are found characteristically in the upper strata of the
deep-sea region, together with the barnacles Scalpellum hamatum and S. striolatum ,
both of which seem to prefer the border layers between the intermediate and abyssal
zones.
One of the most characteristic species of the arctic deep-sea region is the
fascinating sea feather, Umbellula er c rinus , the nake s d stalk of which may some–
times reach the imposing height of 2 meters, carrying on its top a bouquet of
large, flower-like polyps. The species seems to prefer the upper parts of the
deep sea, being usually found at a depth of 1,300 meters but smaller specimens have
also been found in shallow waters, at a depth of but 180 meters in the Siberian seas.
Its habitat is restricted to Greenland waters, the Norwegian Sea, and eastward as
far as 87°04' E. at 79° N. latitude, and is, therefore, an eastern arctic species
(see Fig. 1). The species is not found east of the New Siberian Islands or along
the arctic coasts of North America.
Of interest to note is the case of the Umbellula encrinus which , because of
its short-lived and but feebly vagile larval stage is practically incapable of
penetrating into new regions, is nevertheless comparatively numerous in the deeper
parts of the isolated arctic deeps of Baffin Bay. The fauna of this basin is

EA-Zoo. Broch: Benthonic Fauna

on the whole of the same type as that of the great central polar deep and the
icy depths of the Norwegian Sea. For explanation, it is natural to cite the
polar currents which, after rounding the southern end of Greenland, continue
northward along the western Greenland coast into the northern part of Davis
Strait and Baffin Bay.
Another detached deep-sea basin of arctic waters, the intermediate abyssal
depths of the Okhotsk Sea, will show, it is thought, quite another picture when
the results of the many Soviet expeditions are available. From the scattered
data now at hand we can reach some general conclusions. It may be expected
that species other than the sea anemone Amphianthus margaritacea will be found
to be common to the deep-sea regions of the Okhotsk Sea, the Norwegian Sea, and
Baffin Bay. At all events it is known that the alcyonacean (octocorallan) fauna
clearly exhibits an aberrant aspect: benthonic species common to the Pacific
abound in the Okhotsk Sea, some of them having developed into characteristic
local species. The data accessible to us show with certainty that the fauna of
the Okhotsk deep sea is much richer in species than the central polar deep,
probably due to a strong influx from the Pacific.
Returning to the benthonic life of the central Arctic, Ekman summed up, in
1935, the species endemic to the arcti d c deep sea as follows: (1) entirely abyssal
(below 1,000 meters), 85 species; ( 2 ) mainly abyssal, in the archibenthal region
(below 550 meters), 60 species; and ( 3 ) predominantly archibenthal, 80 species;
total endemic arctic deep sea, 225 species. To this number must be added a
great series of species not restricted to the arctic deep sea but more or less
common to both arctic and boreal deep seas or even the abyssal regions of other
oceans. We must also include several species which are outstandingly eurybathic,
that is to say, common to both deep sea and shallower waters. There are, furthermore,

EA-Zoo. Broch: Benthonic Fauna

some eurythermal species which are apparently independent of differences in
temperatures. S A ccording to Ekman s summary of these, no less than 560 species
of metazoans have been observed living in the arctic deep sea, of which about
40% may be characterized as endemic.
In the shallower parts of the arctic seas, the picture is even more compli–
cated and blurred, especially in the so-called “lower arctic area.”
Here, quite naturally, a strong influence from the boreal regions is apparent
in the fauna. Species of distinctly arctic character, such as the bivalve
Portlandia (Yoldia) arctica, the brachiopold Hemithyrus psittacea , or the brittle
star Ophiopleura borealis , exist side by side with species which are as boreal as
arctic in appearance. Examples of the boreal arctic fauna are the bivalves
Astarte banksi and A. compressa , the brittle star Ophiura sarsi , the deep-sea
prawn Pandalus borealis , etc. Among these are several species of predominantly
boreal character. Such transitional border areas of the Arctic are the northern–
most parts of the Pacific Ocean, the Atlantic coastal banks of southern Labrador,
the northern borders of the Newfoundland banks, the waters along the greater part
of the West Greenland coast, the north coast of Iceland, the Barents Sea, and the
western coastal waters of Spitsbergen.
In the shallower coastal regions of the North American archipelago, the
northern Alaskan coast, as well as in the shelf sea of Siberia, Bering Strait,
and westward to Novaya Zemlya, and the banks around Franz Josef Land, few if any
boreal elements are apparent in the benthonic fauna, which is emphatically
high-arctic in character.
Bottom samplings from this high-arctic coastal area show several endemic
arctic species, and many species seem to be restricted to their special domains
within the area. Whereas a typical shallow-water species, such as the

EA-Zoo. Broch: Benthonic Fauna

lamellibranchiate ( Portlandia (Yoldia) arctica is entirely circumpolar in its
distribution, we find that the endemic arctic isopod Mesidothea has developed
one species, M. sibirica , which is restricted to the Siberian coastal waters
from the Kara Sea to Bering Strait. It can be ha z sarded that parallel instances
of such adaptation will be found eventually in the coastal waters of arctic
North America, where the more or less isolated areas in the sounds of the archi–
pelage provide almost ideal conditions for the development of local races or species.
The estuaries of the great Siberian rivers and their environs with comparatively
brackish water also harbor characteristic local species of varieties, such as
the amphipodous crustacean ( Pseudalibrotus birulai , to mention one characteristic
example. Similar conditions no doubt also prevail in the shallower waters of
arctic North America, giving rise to similar results.
In the eastern, or European and Siberian, parts of the Arctic Sea, several
expeditions have explored the benthonic fauna of the shallower water and have
clearly demonstrated that the distribution of the species is dependent upon
the currents. In the arctic regions this is, on the whole, more evident in
benthonic than in pelagic life and, among the benthonic fauna, is more obvious
in species with short-lived and feebly vagile larval stages than in the more or
less actively moving pelagic fauna. Dealing in terms of centuries-old develop–
ment, we may say that routes followed in the distant past can less easily be
traced, the more actively mobile the species. The study of the more free-floating
benthonic species and their recent distributions has, however, not only demon–
strated the routes of immigration but also, in some cases, g thrown light on
their geographic origins and suggested an explanation as to why many of them
have not as yet been able to attain the circumpolar regions.

EA-Zoo. Broch: Benthonic Fauna

Owing to the greater intermixture of boreal of even more southerly species,
the subarctic coastal waters harbor a much richer fauna than do the high-arctic
regions. Thus the benthonic animal world of the Barents Sea is very rich in
species as compared with that of the Kara Sea, and it is on the whole obvious
that the numbers of species decrease toward the east in these waters, the more
boreal species gradually diminishing. The minimum is evidently attained at the
New Siberian Islands, or between these and Wrangel Island. Here, too, we encounter
the first influence of the Pacific in the amphipods, isopods, and shrimps (for
example, the Spirontocaris macilenta Spirontocaris macilenta ), which, because of a certain amount of
mobility, are able gradually to advance, independent of the weaker ocean currents.
The characteristics of these Pacific-Arctic regions recall those of the
arctic waters affected by the Atlantic of Gulf Stream. At the northernmost parts
of Norway the current has almost lost its Atlantic character but, the temperatures
being somewhat higher than those of arctic water s , some boreal and boreal-arctic
species may still be found in the Barents Sea and even to the north of Spitsbergen
and Novaya Zemlya. However, on the northern side of the New Siberian Islands
the last remnants of the Atlantic current have been so cooled that, given their
greater salinity and resultant greater specific gravity, they sink into the polar
deep along the arctic Siberian slope. The edges of the Siberian shelf north of
the New Siberian Islands, or somewhere between them the Wrangel Island, are the
farthest limits of the benthonic zooplankton of Atlantic origin which are free-
floating or have a short - lived and passively vagile larval stage.
Thus far we have, in our discussion of the possible origins of the benthonic
fauna of the Arctic, referred only to the abyssal regions. In the upper, inter–
mediate or archibenthal parts of the arctic deep-sea region, and the adjacent
deeper parts of the coastal waters occur a great series of species which are

EA-Zoo. Broch: Benthonic Fauna

sometimes both boreal-Atlantic and arctic. To these must also be added several
species of the deeper, cold area of the Norwegian Sea and adjacent waters of
the Arctic which are clearly related to species in the Atlantic deep sea.
Zoologists long ago demonstrated the existence of such so-called “pairs of
species,” the one existing in arctic waters or the “cold area” of the Norwegian
Sea, the other being found in the Atlantic to the south of the submarine ridge
which extends from Scotland to Greenland. In several cases the species are so
deceivingly similar that they are, by former taxonomists, identified as one and
the same. Such was the case with the sea feathers, Umbellula encrinus (of the
Arctic) and U. lindahli (Atlantic intermediate region); the lamellibranchiates,
Pecten frigidus (arctic deep sea) and P. fragilis (Atlantic deep sea); the
starfish, Bathybiaster vexillifer (Arctic) and B. robustus (Atlantic); and
several others. In some species, for example the starfish ( Pontaster tunisspinus
or the brittle star Ophiocten sericeum, the characteristically different individual
groups that have developed in the cold area and the Atlantic deep sea were hitherto
regarded as “varieties,” the morphological differences being deemed too small for
a taxonomic distinction of separate species. In the large deep-sea pycnogonid,
Colossendeis angusta , specimens from the “cold area” and from the Atlantic deep
sea differ in proportions so that, although it is almost impossible to ascribe
a locality to a single specimen, it is quite easy to do so when a number of
individuals from, the two areas are seen side by side. It is, however, still
frequently impossible to decide with certainty whether we have to deal with
separate species or merely with variants of species.
Further extremely interesting examples of closely related species are:
the Sabinea hystrix (Atlantic), S. sarsi (Boreal), and S. septemcarinata (Arctic)
of the Atlantic prawns; and the Pourtalesia jeffreysi (Arctic) and the P. wandeli

EA-Zoo. Broch: Benthonic Fauna

(Atlantic) species of the deep-sea urchins of the genus which is so richly
represented in the deeper layers of the Atlantic Ocean. Confronted by such
evidence, most zoologists now agree that the Atlantic influence on the benthonic
fauna of adjacent arctic waters is predominant and indisputable.
Data added during recent decades to earlier finds have been recorded in
charts for the study of the distribution of benthonic zooplankton in northern
waters. With the aid of these we have been able to trace much of the history of
the arctic bottom fauna without having recourse to reasoning from more or less
hypothetical geological changes. Presumably the features of the arctic seas were,
in the main, during the last geological periods as they are today. On the other
hand, ocean currents have oscillated to some degree in intensity if not in their
course, possibly on account of slight sinking or rising of the earth crust as,
for example, in the environs of Bering Strait.
Several species of the Arctic are doubtless of Atlantic origin. Geographically
these species constitute a characteristic group, usually referred to as “Eastern
Arctic,” or, by Elkman, “Atlantic-Arctic” species. The distribution of the
sea star of the shallower depths, the Icasterias panopla, provides a characteristic
picture of this group (see Fig. 2). It would seem that this species (and accord–
ingly the monotypic genus) had its origin near the borders of the Atlantic drift,
since it flourishes most abundantly around Spitsbergen and in the Barents Sea,
less numerously in the Kara Sea, with its easternmost advanced guards about the
Taimyr Peninsula. On the other hand, the species was apparently able to traverse
the waters between Spitsbergen and Greenland whence it spread along the eastern
and western coasts of Greenland and northward to Baffin Bay. The gap in the
distribution along the southern coasts of Greenland was probably bridged during
a period when the temperature was lower than it is today.

EA-Zoo. Broch: Benthonic Fauna

A similar distribution has been shown in the hydroid species, Lafoëina
maxima , which has been able to penetrate eastward to the New Siberian Islands
but has not as yet been located in the waters of Novaya Zemlya (see Fig. 3).
The arctic shrimp, Sclerocrangon ferox , found at a slightly deeper layer, is
another example of such distribution (see Fig 4). In the Norwegian Sea this
species is also found at the southern border of the cold area, along the con–
tinental shelf. Apparently it is more eurybathic than the former ones above
mentioned, for it has also been found in the upper parts of the deep sea. The
continuous habitat of S. ferox seems to end the western side of Taimyr
Peninsula. However, a stray community found north of the New Siberian Islands
indicates a probable continuous occurrence in deeper layers along the slopes to
the very limit of the habitat of eastern arctic species.
Occasionally met with in Atlantic-boreal waters are arctic species of
eurythermal characteristics. For example, the pycnogonid, Aeginina longicornis,
has been found as far south as Cape Cod on the American coast and in the Skagerrak
at the southernmost point of Norway. In the high-arctic it occurs as far east as
the Taimyr Peninsula.
Early in the history of the explorations of Greenland waters, zoologists
discovered in the bottom fauna species having no occurrence at Spitsbergen or
in the Murman or Barents seas. Later, these same species were found to occur
occasionally in the sounds of the Arctic Archipelago as well as about Bering
Strait and in the northernmost parts of the Pacific Ocean. These elements
of the benthonic world of the Arctic are sometimes, therefore, referred to as
“Western Arctic” species and, by Ekman, “Northwest-Pacific-Arctic” species.
If we compare these distribution data with charts of ocean currents, light
is thrown not only upon the causes of such distribution but upon the possible

EA-Zoo. Broch: Benthonic Fauna

origin of these species. The invasion of the polar seas was no doubt through
Bering Strait. At their weakly vagile stages they would not able to force
their way west through the Siberian shelf sea, only species with actively vagile
benthonic periods of development or adults capable of crawling along the ocean
bottom being able to advance in this direction. On the other hand, eastward
through the shelf waters of the Beaufort Sea and the Arctic Archipelago and
along to Greenland waters, advance is favored by the currents which block advance
from the other direction.
Well-known western arctic species do exist; but the charts almost always
show a gap between Bering Strait and the Canadian Arctic Islands. This may
merely be on account of the incomplete investigation of the fauna of the Beaufort
Sea (the coldest part of the Arctic Sea) as well as on account of the narrowness
of the shelf sea along these coasts. Data from the sounds between the islands
of the Arctic Archipelago are almost equally scanty for the latter reason.
However, if on the basis of present available data we analyze the distribu–
tion of a species such as the arctic shrimp, ( Nectocrangon lar , which shows an
extensive occurrence in boreal and northern Pacific waters bordering on the
Arctic and a rather common occurrence in Greenland waters and along the coasts
of Labrador and Newfoundland, it becomes likely that, upon closer investigation,
the species will be found to occur more or less sporadically all along the arctic
coast of North America (see Fig. 5). The same is true of the hydromedusa,
Catablema multicirrata , and the scyphomedusa, Aurellia limbata , both of which
are resticted to rather shallow waters by their polyp stages of development; of
the ascidian, Boltenia ovifera ; and of the shrimp, Spirontocaris groenlandica ,
which, like Nectocrangon lar, penetrates a little farther into boreal regions.
(See Figs. 6, 7, and 8.)

EA-Zoo. Broch: Benthonic Fauna

These examples, selected at random, differ inter se in that two
coelenterates, Catablem e a multicirrata and Aurellia limbata , have not been found
in East Greenland waters but only along the western coast. This can be corre–
lated to the fact that at their polyp stage of development they seem to be
restricted to shallow and sheltered localities, such localities being found in
the Arctic Archipelago and not along the slopes of the shelf sea or the exposed
coasts of northernmost Greenland. The more eurybathic species such as the ascidian
or the shrimps can, on the other hand, make their way along the northernmost coasts
and into East Greenland waters, but have apparently been unable to cross the polar
currents and so reach the shelf waters of Spitsbergen.
That Greenland waters harbor both eastern and western arctic species becomes
evident from the accounts here given of the eastern and western arctic components
of the benthonic fauna of the shelf sea and adjacent upper layers — the inter–
mediate or archibenthal layers — of the deep sea. This rich fauna is further
enriche s d by a strong admixture of Atlantic-boreal elements and occasional rein–
forcements from the Atlantic deep sea. Along the western Greenland coast,
especially on the coastal banks, this richness of the fauna is notable, but
becomes poor in the straits and sounds west of Davis Strait and Baffin Bay, at
least, according to present data.
We have found, then, that the eastern arctic species have little potentiality
of invading the circumpolar regions, this being possible only to benthonic species
having at most weakly vagile larval or polyp stages of development. In western
arctic species, however, invasion of the circumpolar regions would seem to be
possible. When the species is so eurybathic that it can live and propagate in
border layers of the cold area along the submarine ridge from Greenland to
Scotland, there is the possibility that the species can gradually invade high-arctic

EA-Zoo. Broch: Benthonic Fauna

regions through the mutability of the border layers.
Several high-arctic species have doubtlessly developed from primarily
western arctic forms. It is of speculative interest to try to trace their
origin. Taking as an example the brittle star, Ophiura (Stegophiura) nodosa,
we find an abundance in the Bering Sea, and the scattered finds at Sakhalin
and Sitka seem to indicate that the species originated in Arctic-Pacific waters
(see Fig. 9).
Comparing the distribution of Ophiura (Stegophiura) nodosa with that of the
lamellibranchiate, Portlandia (Yoldia) arctica , we find that Bering Strait
represents a barrier to the latter. According to the quaternary finds, this
strait has always prevented any expansion of habitat into Pacific waters on the
part of this species. Whereas O. (S.) nodosa and other species with similar
distribution have in all probability invaded the polar sea through Bering Strait,
P. (Y.) arctica evidently had its origins in the polar sea and, although it has
not been able to pass through Bering Strait, it has shifted its southern limit in
European waters according to fluctuating hydrographical conditions, requiring as
it does the isothern of - + 2.5°C. in bottom mud. The P. (Y.) arctica lived, it has
been shown, during the last glacial period along the southern coasts of Scandinavia,
whereas its southern limits at the present time are at Spitsbergen and at the
entrance to the Kara Sea, with an isolated community in the White Sea (see Fig. 10).
The amphipod crustacean, ( Stegocephalopsis ampulla , furnishes another interest–
ing example of a typically circumpolar species of high-arctic origin. If we are
to judge by present data, the species is scarce in its occurrence and extremely
stenothermal in character (see Fig. 11). That it has never been found except at
temperatures at or below -0.1°C. leads us to conjecture that it may have a more
common occurrence along the slopes of the polar central basin in the deeper parts

EA-Zoo. Broch: Benthonic Fauna

of the shelf sea which are areas as yet comparatively unexplored. Invasion
from the Atlantic or Pacific in the past is improbable, its nearest related
species being an insufficiently described one found in the abyssal region of
the Indian Ocean which has been placed in the same genus, but with a query.
Before concluding, it may mall be well to recapitulate what is meant by
the “arctic deep-sea region.” It comprises the central, or polar basin, and
the adjacent deeps of the Norwegian Sea, Baffin Bay, and the Sea of Okhotsk.
The shallower of shelf-sea region of the arctic seas may be said to be one con–
tinuous region, in spite of Bering Strait which almost cuts off from the central
polar sea the northernmost waters of the Pacific Ocean and the adjacent Sea of
Okhotsk.
In the benthonic fauna of the shelf region, there are remarkable differences
between the northern Atlantic and northern Pacific waters, where the arctic-boreal
species play a great part in the composition of the animal world. The admixture
of typically Pacific elements is more apparent in the Okhotsk than in Bering Sea.
In fact, the Sea of Okhotsk is the most aberrant part of the arctic seas. But
quite apart from this, the shelf sea, even of the central arctic region, discloses
a far more varied fauna than does the deep sea, the reasons for which we have
already mentioned. Many of these differences may be only apparent, not real, and
will disappear with more extensive field work along the American coasts.
However, a close study of circumpolar species and a comparison with boreal
species indicated that the “white spots” on the distribution charts may not be
solely the result of inadequate investigation. In many cases the conditions of
life in the high-arctic waters have reduced in recent times the members of species
both in Siberian and American waters, and hydrographical changes may have set up
barriers between the boreal-arctic species of the Pacific and Atlantic oceans.

EA-Zoo. Broch: Benthonic Fauna

We have reason to believe that temperatures of the shelf sea in earlier times
were higher than they are today. The supposition is strengthened by the occur–
rence of relict populations as, for example, the communities of the mussel,
Mytilus edulis, found at the entrance to the Kara Sea, widely separated from
the usual habitat of the species, which has its easternmost limit on the eastern
coast of Norway bordering the Barents Sea. This warmer, Postglacial period when
the Mytilus edulis occurred in the region of Spitsbergen dates back to 2500 to
4000 years ago.
On the other hand, as stated above, the occurrence of such species as the
Portlandia (Yoldia) arctica in the White Sea would lead to the inference that
high-arctic conditions once prevailed in what are in present times boreal-arctic
regions.

EA-Zoo. Broch: Benthonic Fauna

BIBLIOGRAPHY

1. Appelőf, A. “Die Decapoden Crustaceen,” Bergens Mus. Meeresfauna
vol.2-3, 1906.

2. ----. “Invertebrate bottom fauna of the Norwegian Sea and North
Atlantic,” Murray, John, and Hort, J. The Depths of
the Ocean . London, Macmillan, 1912.

3. Berg, L.S. “Die bipolar Verbreitung der Organismen und die Eiszeit,”
Zoogeografica vol.1, 1933.

4. ----. “Uber die amphiboreale (diskontinuierliche) Verbreitung der
Meeresfauna in der nőrdlichen Hemisphäre,”
Zoogeografica vol.2, 1934.

5. Berthelsen, E. “Contributions to the animal ecology of the fjords of
Angmassalik and Kangerdlugssuaq in East Greenland,”
Medd. Grø n land vol.108, no.3,1937.

6. Birulia, L. “Beiträge zur Kenntnis der Decapoden-Krebse der eurasiatischen
Arctis,” Akad.Nauk. Classe Phys. - Mat. M e é m. Zapiski
ser.8, vol.29, 1910.

7. Borg, F. “Uber die geographische Verbreitung der innerhalb des
arktischen Gebietes gefundenen marinen Bryozoen,”
Archiv für Naturgesch . Vol.2, 1933.

8. G B reitfuss, L. “Die biologischen Problems der Arktis,” Arktis
l. Jahrg., H.3/4, pp.97-112, 1928.

9. Broch, Hjalmar. “Anthozoa, mainly from Pacific waters, collected by
U.S.S.R. expeditions 1930-1932,” Leningrad. Gosudarst–
vennyi Gidrol.Inst. Issled.Morei S S . SR vol.23, 1940.
(Russian and English.)

10. ----. “Cirripedia thoracica von Norwegian und dem norwegischen Nordmeer,”
“Norsks Videnskaps-Akad. Mat.-Nat.Kl. Skrifter , 1924.

11. ----. “Einige Probleme der giogeographischen Abgrenzung der artischen
Region,” Berlin. Univ.zool.Mus. Mitt . 1933.

12. ----. “Grősse der Meerestiere und Temperatur ihres Lebensraumes,”
Naturwissenschaften vol.21, 1933.

13. ----. “Noen dyregeografiske trekk i nordhavenes bunndyreverden,”
Norsk Geogr.Tid [: ] skr . vol.6, 1937.

14. ----. Oktokrallen des nőrdlichen Pazifischen Ozeans und ihre Beziehung
zur atlantischen Fauna,” Norske Videnskaps-Akad.
Mat.-Nat.Kl. Skrifter , 1935.

EA-Zoo. Broch: Benthonic Fauna - Bibliography

15. ----. “Post-glacial interchange between Pacific and Atlantic deeper
living boreal fauna!” Norsk Geogr.Tidsskr . vol.12, 1949.

16. Brotskaia, V.A. and Zenkevich, L.A. “Kolichestvennti Uchet donnoi
Fauny Berentsova Moria” (Quantitative evaluation of the
bottom fauna of the Barents Sea.) Vaesoiuznyi Nauch. Issled.
Inst.Rybnogo Khoz.Okeanogr., Moscow. Trudy vol.4, 1939.
(Russian with English r e é sum e é .)

17. ----, and Zenkevich, L.A. “Materialy po kolichestvennomu nchetu donnoi
fauny Barentsova, Belogo i Karskogo morei. 6. Kolichestvennyi
uchet donnoi fauny Cheschoi guby.” (Materials for the quan–
titative evaluation of the bottom fauna of the Barents, White
and Kara Seas. 6. A quantitative evaluation of the bottom
fauna of the Cheshskaia Bay.), Gosudarstvennyi Okeanogr.
Inst.,Moscow. Trudy vol.2, no.2, pp.41-57, 1932. (Russian
with English summary.)

18. Carlgren, Oskar. “Die Brutpflege der Actiniarien,” Biologisches
Zentralbl. Vol.21, 1928.

19. ----. “Ceriantharier, Zoantharier och Actiniarier,” Medd.Grønland,
Suppl. Vol.23, no.24, 1928.

20. Carpenter, W.B. “Preliminary report of dredging operations in the sea
to the north of the British Islands in H.M.S. ‘Lightening,’”
Roy.Soc.Lond. Proc . Vol.17, 1869.

21. Dall, W.H. “On climatic conditions at H N ome, Alaska, during the Pliocene,”
Amer.J.Sci . vol.23, 1907.

22. ----. “Summary of the marine shellbearing mollusks of the NWcoast of
America from San Diego to the Polar Sea.” U.S.Nat.Mus. Bull .
no.112, 1921.

23. Deriugin, K.M. “Fauna belogo moria i usloviia ee sushchestvovaniia.”
(Fauna des weisen Meeres und ihre Existenzbedingungen.),
Leningrad. Gosudarstvennyi Gidrol.Inst. Issled.Morei SSSR
no. 7/8, 1928. (Russian with German r e é sum e é .)

24. Gorbunov, G.P. “Fauna Crustacea-Decapoda Severnoi Poloviny Karskogo
Moria,” (The Decapod crustacea of the northern half of the
Kara Sea.), Leningrad. Arkticheskii Nauchn-Issled.Inst.
Trudy vol.9, pp.59-77, 1934.

25. ----. “Materialy no faune Decapoda Zemli Frantsa-Iosifa.” (Material
on the Decapod fauna of Franz Joseph Land.), Ibid , vol.2,
pp.80-91, 1932. (Russian with German r e é sum e é .)

26. Gurianova, Ev. “On the question of the composition and origin of the
fauna of the polar basin bassalia,” Akad.Nauk. Comptes Rendus
( Doklady ) vol.20, no.4, 1938. (In English.)

EA-Zoo. Broch: Benthonic Fauna - Bibliography

27. ----. “Zoogeograficheskii ocherk fauny Isopoda arktiki.” (Zoogeographi–
cal study of the arctic Isopods .), Arctica no.2, pp.127-52,
1934. (Russian with English resum e é .)

28. ----. “Zur Zoogeographie der Crustacea-Malacostraca des Arktischen
Gebietes,” Zoogragrafica vol.2, 1936.

29. Hartmeyer, R. “Studien an westgrőnlőndischen Ascidien,” Medd.Grønland
vol.62, pp.1-37, 1923.

30. Idelson, M.S. “Materialy po kolichestvennomu uchetu donnoi fauny
Barentsova, Belogo i Karskogo Morei,” (Materials for the
quantitative evaluation of the bottom fauna of the Barents,
White and Kara Seas. No.7. Distribu g t ion of the benthos
biomass in the southern Barents Sea. The influence of different
factors in the density of the sea bottom population.),
Gosudarstvennyi Okeanogr.Inst. G Trudy vol.3, 1934.
(Russian with English resum e é .)

31. Jensen, Ad.S. “Two new West Greenland localities for deposits from the
Ice Age and the postglacial warm period,” Danske Vidensk.
Selsk. Biologiske Medd . Vol.17, 1942.

32. Jungersen, H.F.E. “Alcyonaria, Antipatharia og Madreporaria,” Medd .
Grønland vol.23, no.13, 1915.

33. ----. “Fra Ingolf-Expeditionen. Bemaerkninger om Dybhavsfaunaen og
dens Fordeling i de nordlige Have,” Geogr.Tidsskr . vol.14, 1898.

34. Kramp, P.L. “Hydroids collected in West-Greenland Fjords in 1911 and
1912,” Medd.Grønland vol.91, no.3, 1932.

35. Kűkenthal, W. “Die marine Tierwelt des arktischen und antarktischen
Gebietes in ihren gegenseitigen Beziehungen,” Berlin. Univ.
Inst.fűr Meeresk. Verőff . Vol.11, 1907.

36. Molander, A.R. “Northern and arctic invertebrates in the collection of
the Swedish State Museum. VII. Alcyonacea, Svenska Vetenskapsa–
kad. Handl . n.s., ser.4, vol.51, 1915.

37. Murray, John, and Hjort, J. The Depths of the Oceans . London, Macmillan,
1912.

38. Nordgaard, O. “Bryozoa from the arctic regions,” Tromsø/ Mus. Aarsh.
vol.40, 1918.

39. Popov, A.M. “Hydrobiological explorations in the Nordenskiőld Sea,”
Internationale Rev.der Gesamt.Hydrobiol.u.Hydrogr . vol.25,
1931.

EA-Zoo. Broch: Benthonic Fauna - Bibliography

40. Retovskii, L.O. “Fauna Crustaces-Decapoda Sibirskikh Morei.”
(Crustacean-Decapod fauna of the Siberian arctic.), Leningrad.
Arkticheskii Nauchn-Issled.Inst. Trudy vol.33, pp.7-29, 1936.
(Russian with German resum e é .)

41. Rylov, V.M. “Alcyonaceae, sofrannye ekspeditsiei plovuchego Morskogo
Nauchnogo Instituta v 1921 g.) (Alcyonaceae, gesamelt von
der Expedition des Schwimmenden Wissenschaftlichen Meeresinstitut
im Jahre 1921.), Morskoi Nauch.Inst., Moscow. Trudy vol.2,
pt.1, pp.61-78, 1926.

42. ----. “Hydroidea-Athecata, sofrannye ekspeditsiei Instituta v 1921 g.”
(Hydroidea-Athecata, aus den Sammlungen der Expedition den
Institus im Jahre 1921.), Plovuchii Morsk.Nauch.Inst.,
Moscow. Trudy vol.9, 1924. (Russian with German resum e é .)

43. ----. “Hydroidea in Alcyonaria, sofrannye v Barentsovom More Murmanskoi
Biologicheskoi Stansiei vo vremia reisov po kolskomu meridianu
v 1921 g.” (Hydroidea et Alcyonaria, collectionn e é s dans la mer
de Barenz par la Station Biologique du Mourman pendant les
cr o ô is e é es le long du m e é ridien de Kola en 1921.), Akad.Nauk.Zool.
Muz. Ezhegodnik vol.27, pt.2/3, pp.233-46, 1927. (Russian with
French resum e é .)

44. Sars, G.O. Mollusca Regionis Arcticae Norvegiae. Christiania , 1878.

45. Schellenberg, A. “Die Gammariden Spitzbergen” Berlin.Univ.Zool.Muz.
Mitt . Vol.11, 1924.

46. Shorygin, A.A. “Iglokzhie Barentsova Moria.” (Die Echinodermen des
Barentsmeeres.), Morskoi Nauch.Inst.Moscow. Trudy vol.3, no.4,
1928. (Russian with German resum e é .)

4 6 7 ----. “Iglokzhie Belogo Moria.” (Die Echinodermen des Weissen Meeres.),
Morskoi Nauch.Inst., Moscow. Trudy vol.2, no.1, pp.3-59, 1926.
(Russian with German resum e é .)

48. ----. “Iglokzhie, sofrannye ekspeditsiiami Plovuchego Morskogo Nauchnogo
Instituta v 1921, 1923 i 1924 godakh.” (Echinod ermata aus den
Sammlungen der Expeditionen des Wissenschaftlichen Meeresinstitus
im Jahre 1921, 1923 und 1924.), Plovuchii Morsk.Nauch.Inst.,
Moscow. Trudy vol8, 1925. (Russian with German resum e é .)

49. Sivertsen, E. “Crustacea Decapoda, Euphausiacea and Mysidacea of the
Norwegian expeditions to East Greenland (1929-1932),” Norsk
Polarinstitutt. Skrifter no.66, 1935.

50. Spärck. R “Contributions to the animal ecology of the Franz Joseph
Fjord and adjacent East Greenland waters. I-II,” Medd. Grønland
vol.100, no.1, 1933.

EA-Zoo. Broch: Benthonic Fauna - Bibliography

51. Stephensen, K. “Grønlands Krebadyr og Pycnogonider,” Ibid . vol.22,
no.1, 1913.

52. ----. “The Scoresby Sound Committees 2nd East Greenland Expedition to
King Christian IX’s Land. Crustacea and Pycnogonida,” Ibid .
vol.104, no.15, 1933.

53. ----. “Zoogegraphical investigations in certain fjords in Southern
Greenland with specific reference to Crustacea, Pycnogonida
and Echinodermata,” Ibid . vol.53, no.3, 1916.

54. Strelnikov, I.D. “La faune de la mer de Kara et ses conditions
ecologiques,” Acad.Sci. Comptes Rendus vol.188, 1929.

55. Theel, Hj. “Northern and arctic invertebrates in the collection of the
Swedish State Museum. II. Priapulids, Echiurids, etc.,”
Svenska Vetenskapsakad. Handl . n.s., ser.4, vol.40, 1906.

56. Thorson, Gunnar. “Contribution to the animal ecology of the Scoresby
Souhd Fjord Complex (East Greenland),” Medd.Grønland vol.100,
no.3, 1934.

57. ----. “Investigations on shallow water animal communities in the
Franz Joseph Fjord (East Greenland) and adjacent waters,”
Ibid . vol.100, no.2, 1933.

58. ----. “The larval development, growth, and metabolism of arctic marine
bottom invertebrates compared with those of other seas,” Ibid .
vol.100, no.6, 1936.

59. Ushakov, P.V. “Materialy po gidroidam arkticheskikh morei SSSR.”
(Materials on the hydroids of the arctic seas of U.S.S.R.),
Leningrad, Arkticheskii Nauchn.-Issled.Inst. Trudy vol.50,
pp.5-34, 1937. (Russian with English resum e é .)

60. Vibe, Christian. “Preliminary investigations on shallow water animal
communities in the Upernavik- and Thule-districts (Northwest
Greenland),” Medd.Grønland vol.124, no.2, 1939.

61. Winkler, M.E, and Schmitt, W.L. “Notes on crustacea chiefly Natantia,
collected by Capt. R.A. Bartlett in arctic seas,” Wash.Acad.
Sci. J . vol.26, 1936.

62. Zenkevich, L.A. “Materialen zur quantitative Untersuchung der Bodenfauna
des Barents und des Weissen Meeres,” Morskoi Nauch.Inst.,
Moscow. Trudy vol.2, no.4, pp.56-64, 1927. (German only.)

EA-Zoo. Broch: Benthonic Fauna - Bibliography

63. ----. “Nekotorye Momenty Zoogeografii Severnogo Polarnogo Basseina
v sviazi e voprosom o ego paleograficheskom proshlom.”
(Beiträge zur Zoogeographie des nőrdlichen Polarbassins im
Zusammenhang mit der Frage Über dessen palägeogfaphische
Vergangenheit.), Zoologicheskii Zhurnal vol.12, 1933.
(Russian with German resum e é .)

64. ----, and Brotskaia, V.I. “Materialy po ekologii rukovodiashchikh form
bentosa Barentsova Moria.” (Some date on the ecology of
dominants in the bentos of the Barents-Sea.), Moscow, Univ.
Uchenye Zap.Wiss.Ber . vol.13, pp.203-26, 1937. (Russian with
English resum e é .)

Hjalmar Broch

Plankton of Arctic and Subarctic Seas

EA-Zoology
(M . ax J. Dunbar)

PLANKTON OF ARCTIC AND SUBARCTIC SEAS

CONTENTS
Page
Chordata 7
Enchinodermata 8
Chaetognatha 8
Mollusca 9
Crustacea 9
Annelida 13
Coelenterata 13
Protozoa 16
Distribution 16
Bibliography 21

EA- [: ] Zoology
(M. J. Dunbar)

PLANKTON OF ARCTIC AND SUBARCTIC SEAS
The more productive part of the northern regions is the sea, not the
land. The economy of the Eskimo, even in districts rich with commercially
valuable fur, is based upon the life produced in the arctic and subarctic
waters.
Production in the sea is not easy to measure. There are as yet few
estimates of the bulk or weight of living matter produced in unit volumes of
different types of sea water, and in all cases the possible error may well be
considerable. There has as yet been no estimate of production in arctic water,
the most northerly being that of Kreps and Verzhbinskaia (28) in the Barents
Sea. The summary of estimates of production published by Riley (32), however,
shows higher figures for the more northern parts of the Temperate Zone than
for the tropical regions. It has long been supposed on purely cursory evidence
that his was so, but we have not yet reached the stage where we can establish
it with certainty. In making the production estimates, much depends on the
proper evaluation of such factors as speed of population turnover (from brood
to brood), the depth of the euphotic zone (the light zone in which plant cells
can grow and divide), the speed of loss of plant cells by sinking from the
surface layers, and the variation in production, in any given area, throughout
the year.

EA- PB. Zoo. Dunbar. Plankton

The basic life in the sea, as on the land, is the plant production, the
bulk of which is planktonic (phytoplankton), the word “plankton” being an
inclusive term for all the forms of life, both plant and animal, which cannot
swim fast enough to be independent (insofar as locomotion is concerned) of the
ocean currents, and which are therefore carried with them. Thus the pelagic,
or free-swimming larval stages of benthonic animals make up an important part
of the marine plankton, the so-called “temporary” plankton, present in the
plankton only at specific stages of their life cycles and specific times of
year. Most of the zooplankton, however, consists of animals whose whole lives
are spent plantonically.
Arctic water and the arctic climate have several characteristic favorable
to the growth of phytoplankton, compared to tropical or subtropical water. The
low temperatures allow high concentrations of dissolved gases, both carbon dioxide
for photosynthesis and oxygen for energy requirements; the long summer days allow
photosynthesis to continue for longer periods (during the summer season) than in
regions closer to the equator; and it is probable that the greater viscosity of
the cold water has an important effect on the flotation of the plant cells, so
that the period of their sojourn in the ouphotic zone is extended, when com–
pared with warmer regions, despite the fact that the euphotic zone in equatorial
regions is considerably deeper than toward the poles, for obvious reasons.
Another characteristic of polar water which appears to encourage phyto–
plankton growth and division, following certain recent experimental studies,
is the quantity of melting ice normally present during the arctic summer. Water
resulting from the recent melting of ice is rich in the trihydrol molecule.
(H 2 O)3, a polymer of water. Such water has been shown to stimulate the growth
and multiplication of plant cells used experimentally ( Euglena , Spirogyra ,

EA-Zoo. Dunbar. Plankton

Nitzschia ) (1; 2; 3; 18).
Brandt (6) suggested that the productivity of the colder water of the
ocean might in part be due to the reduction of the activity of the denitrifying
bacteria (which reduce salts containing nitrogen to free gaseous nitrogen) in
water of low temperature. This has not been supported by later work (19, p.113),
which has derogated the importance of these bacteria in the metabolism of the sea.
It has been suggested that the great numbers of sea birds which breed in
the North provide a constant supply of nutrient salts, or fertilizers, during
the whole of the summer. This effect is circular, since the numbers of the
birds depen t d ultimately on the food supplied by the sea; but there is little
doubt that the fertilizing effect of sea birds is important. In regions par–
ticularly rich in colonies of birds (kittiwake, murre, dovekie, etc.), such as
the interior of Disko Bay in West Greenland, the phytoplankton production is
most remarkably high, so high as to be immediately apparent at sight, and so
that plankton nets used in those waters are soon clogged completely and become
useless. Moreover, the phytoplankton in such areas does not appear to show the
normal spring and autumn peaks of production, but to continue at maximum pro–
duction all summer long. These effects are apparent also in the water surround–
ing isolated bird colonies, in otherwise normal water areas.
Against these characteristics, it is necessary to put two properties which
operate in the opposite direction. The shallower euphotic zone has already been
mentioned; it has the effect of conc d e nitrating the phytoplankton, and consequently
some of the zooplankton, [: ] into a shallower vertical range than is found in
tropical waters, since the vertical range of possible plant growth is restricted.
Also, the low temperatures (an asset in the matter dissolved gases) have the
effect of reducing growth rates, so that the intervals between breeding periods

EA-Zoo. Dunbar. Plankton

In the plankton are longer than in warmer water; the population turnover must
be supposed to be slower, and the mortality rate per brood perhaps higher,
than elsewhere.
The growth-rate effect has resulted, in those planktonic animals so far
studied, in the establishment of a type of breeding cycle which may be peculiar
to cold-water regions. In Sagitta elegans arctica , Themisto libellula , and two
species of Thysanoessa , an alternating, or two-phase, breeding cycle was found
in which two independent broods, separated in age by half a year or by one year
(according to species), exist side by side, neither being parental to the other.
During the breeding season, three separate size groups are present; the breeding
group, the newly developed young, and the intermediate adolescent group (12; 7;
13). Size frequencies of this sort, with the implied two-phase breeding cycle,
have also been recorded in Anonyx nugax from East Greenland (38), and in
Euphausia superba in the Antarctic waters (35). Such breeding cycles have the
effect of offsetting the check on population resulting from slow growth rates
in cold water. They have the interesting corollary that the two broods present
at any one time are genetically separate, and unless the system goes out of
phase in one way or another, the conditions are presumably favorable for the
development of differences between the broods which might in time lead to
speciation.
If this analysis of the productivity of arctic water is correct, areas
in which arctic water mixes with more temperate water should be especially
productive, for in such regions the inhibiting factors of slow growth rates
should be removed. Such regions do in fact appear to be remarkably productive
of life; for it is precisely in the mixing areas that the great commercial
fishers are developed, as on the banks of Nova Scotia, Newfoundland, and

EA-Zoo. Dunbar. Plankton

West Greenland, off rhe coasts of Iceland and of Norway, and in the North Sea.
Estimates of plankton production in these regions are correspondingly high.
Without as yet going into detailed definition, it is to the productivity
of the sea water that Madsen has recently directed attention for the finding
of a working criterion for the delimitation of the arctic and subarctic zones
in the sea (29, 30). In a study of the littoral fauna of the Arctic and Sub–
arctic, Madsen found that the barren intertidal zone of the high-Arctic began
and ended quite suddenly; that the littoral fauna, for instance, of South
Greenland, characterized by certain key species, disappeared suddenly at
Angmagasalik on the east coast and at Upernivik on the west coast. He showed
that a purely climatic criterion would not suffice to explain this pattern,
and suggested that the productivity of the water itself was the limiting factor
involved (see “Littoral Fauna of the Arctic ). It has been pointed out that this
criterion may well apply also to other parts of the marine fauna besides the
littoral, and that the essential factor in inducing the greater productivity
of the southern part of northern waters may be the admixture of nonarctic water;
thus a natural and practical criterion for the delimitation of arctic from
subarctic water becomes immediately available (10).
The arctic marine plankton is remarkable for the size attained by the
individual members, when compared to those of temperate or tropical waters.
i I t is the general rule that poikilothermic inhabitants of cold water grow to
a remarkably large size; this applied both to individuals of species with wide
range from temperate to arctic (as the chaetognath Sagitta elegans ), and to
the northern or cold-water species which replace tropical or temperate forms
within any one genus (such as the copepod Calanus hyperboreus which to some
extent replaces Calanus finmarchicus in the high-Arctic). The factors responsible

EA-Zoo. Dunbar. Plankton

for this phenomenon have not yet been fully analyzed; one important factor is
the effect of temperature on development of the gonads. “Delayed sexual
maturity, which favors growth in size, appears to be directly dependent on
retardation of growth at lower temperatures, and this is a common character–
istic of northern marine creatures” (20).
The size effect has been studied in some detail in the field by two
Scandinavian workers, Sømme and Jespersen. Working on the marine copepod
Crustacea of West of East Greenland waters, Jespersen has demonstrated the
presence of two quite separate size groups in adult Calanus finmarchicus of
both sexes (22; 23). The same effect has been recorded in Calanus hyperboreus
in the waters of West Greenland (23a), and in the Norwegian Sea (37). These
differences were ascribed to the presence of a mixed population with two
different histories, one group having developed in polar water, the other in
boreal water, the individuals of larger body size belonging to the colder water.
However, since the discovery that the populations of C. hyperboreus from north–
east Greenland, clearly from polar water, correspond to the smaller size group
of West Greenland (23), this theory must be left in abeyance. We have thus no
plausible explanation for the size difference in this species.
The marine plankton of the North follows the general rule that species
are fewer in number in polar than in other areas, but are often represented
by greater numbers of individuals. The number of species in the [: ] northern
plankton, nevertheless, is enormous, as would be expected in so varied an ecolo–
gical grouping. In the following account of the species, only the more abundant
forms are discussed and those less abundant forms which display some feature
of special interest. Only the zooplankton is considered.

EA-Zoo. Dunbar. Plankton

Chordata
Pure arctic water is not rich in fish; consequently, fish eggs and larvae
are seldom dominant or even abundant in the plankton. Most of the fish present
in arctic water lay demersal eggs, which do not in any event appear in the
plankton. In subarctic regions, however, with considerable proportions of
boreal water, the eggs of fish are very abundant as temporary plankton. Thus,
the eggs of the Atlantic cod ( Gadus callarias ) appear in March and April in
the subarctic waters of West Greenland, especially in the sheltered fjord
waters where the cod spend the winter. Larval fish of many species are found
in the plankton; even the fish which lay demersal eggs pass through a stage in
which the young are pelagic, and since their powers of swimming are limited,
these young fish are included in our definition of the plankton. In certain
localized coastal areas, close to the influx of fresh water, the young of the
Cottidae (sculpins) are sometimes present in the early summer in large numbers,
even on occasion to the exclusion of other planktonic forms. Thus several
hundred young specimens of the Greenland sculpin, Myoxocephalus scorpius
groenlandicus , up to 26 millimeters in length, were taken in a single haul
in Glasgow Inlet, Lake Harbour, in v southern Baffin Island (9). Other fishes
frequently caught in larval stages in the plankton are Gymnocanthus tricuspis
(sculpin); Agonus spp. And Aspidophoroides spp. (poachers and alligator fishes);
Eumicrotremus (lumpsucker); various liparian s ; Lumpenus (eel blenny); Stichaeus
(northern blenny). Many planktonic eggs and larvae of fishes found in both
arctic and boreal waters are described by Ehrenbaum (14).
The Urochordata are represented in the arctic and subarctic plankton almost
entirely by the Larvacea; the Thaliacea and the larvae of the Ascidacea being

EA-Zoo. Dunbar; Plankton

comparatively rare. The commonest of the Larvacea is Oikopleura , which is
the summer is often very abundant; the house, or test, being then frequently
seen at the surface. In the Labrador Sea and Newfoundland area, O. vanhőffeni
has been found to be characteristic of arctic water, and O. labradoriensis more
abundant in mixed arctic and Atlantic water (16). The genus Fritillaria is
also fairly common.
Echinodermata
Larval stages of bottom-living animals tend to be somewhat, reduced in the
time dimension in cold water, for reasons still unknown. Consequently various
larvae of the echinoderms are collected in the plankton nets only during a very
short period in the spring.
Chaetognatha
The arrowworms (or glass worms) are represented by several species, by far
the commonest of which is Sagitta elegans arcitca , separated from the typical
elegans form of the temperate regions by much larger size, a relatively shorter
tail segment, and differences in the numbers of oral hooks. S. elegans arctica
is a neritic form, and is found usually in the upper 50 to 100 meters; it is
very common, sometimes dominating the plankton hauls in fjord waters. It is
an exceedingly voracious creature, and will attack animals as large as itself;
its normal diet consists of copepods. Large specimens up to at least 50 millimeters
in length have been found, and individuals over 40 millimeters are common. Other
chaetognaths occur only in much smaller numbers. Next in abundance to S. elegans
is probably Eukrohnia hamata , a deepwater temperate form, found also in shallower
water in the Subarctic. In areas with much Atlantic or Pacific admixture, more
southerly forms are naturally found, and Atlantic species are of course common

EA-Zoo. Dunbar; Plankton

in the Labrador Sea and in the warm layer underlying the arctic water of the
polar basin. Such temperate or cosmopolitan species as Sagitta hexaptera ,
S. serratodentata , and S. elegans elegans are included in this group.
Mollusca
Trochophore and veliger larvae of bottom-living mollusks are common,
and they appear to be produced during the whole of spring and summer. In more
temperate regions, these larvae are found in plankton during the entire year.
The same may be true of arctic waters, but we have as yet almost no winter field
work to go on. Of the pelagic Mollusca, two species are very abundant in arctic
water, and are indeed so characteristic as to be used as indicators of arctic
water in mixing areas. These are Limacina helicina , the little black “sea
butterfly,” and Clione limacine , a larger, yellow-brown form. L. helicina is
often present in great numbers close to the surface in the late summer and
early fall, during which time it forms an important food of various fish, in–
cluding the Atlantic cod in West Greenland and in Ungava Bay; the ringed seal,
Phoca hispida, has also been found to be eating this little mollusk in
September (11). According to unpublished information from Dr. George MacGinitie,
from Point Barrow, Alaska, Clione has been much more abundant than Limacina in
that area in recent years.
Crustacea
The decapods are not planktonic as adults, although prawns and shrimps are
sometimes caught in plankton nets towing near the bottom. The larval stages,
however, are very abundant in the plankton during the spring and early summer,
as they are in most parts of the coastal waters of the world.
Euphausiids . The euphausiids (order Euphausiacea) are found in deeper

EA-Zoo. Dunbar; Plankton

water than the bulk of the coastal plankton, and in the deep oceanic water
beyond the continental shelves. The important species ecologically are Thysanoessa
raschill , T. inermis , and Meganyctiphanes norvegica . All three are found in
boreal water as well as arctic water, in fact, they are more common in the
southern parts of their ranges. Meganyctiphanes is known from the Mediterranean.
The euphausiids form the bulk of the food of certain whales, including the blue
whale in the North Atlantic region, and are known to whalers a [: ] “krill.” They
are also eaten quite extensively by the harp or saddleback seal ( Phoca groenlandica )
and by the ringed seal ( P. hispida ), especially in subarctic areas with boreal
waters present. In pure polar water, their place in the seal economy appears
to be taken by the hyperiid amphipod Themisto . The same seems to be true for
the food habits of many fishes, including various species of cod, the arctic
char ( Salvelinus alpines ), and the capelin ( Mellotus villosus ), which commonly
eat Thysanoessa in subarctic waters.
Mysids . Mysids (order Mysidacea), on the continental shelf, keep close to
the bottom as a rule; but they are frequently caught in plankton nets and are
normally included in the planktonic fauna. In coastal waters the commonest
species is Mysis oculata , which occupies approximately the same ecological
position, at least in the food chain, as does Thysanoessa . It is not uncommon
to find Mysis oculata swarming in shallow water in the neighborhood of freshwater
influxes, close to the surface. It is an arctic circumpolar littoral species,
often taken in the stomachs of seals and fish. It is also found as an arctic
relict in the Baltic Sea. Mysis ( Mictheimysis ) mixta is much less abundant,
but fairly common, and is not as strictly arctic as oculata . In deeper water
(usually below 100 meters in the daytime), two species of Boreomysis , among the
largest mysids known, are common in northern waters: B. arctica being a subarctic

EA-Zoo. Dunbar; Plankton

form, which is replaced by S B . nobilis as the boreal influence from the south
becomes weaker.
Amphipods . The amphipods (order Amphipoda) are both plentiful and varied
in the arctic plankton, sometimes dominating the planktonic scene. One of the
most successful and widespread crustacean orders, they function as scavengers
in many animal communities. Although they there are many more littoral and benthonic
spcies than planktonic, they have nevertheless invaded the water layers with
typical success. In the planktonic habitat the suborder Hyperiidea are the
dominant amphiods, and have become more completely planktonic in habit than
either the Gammaridea (the largest amphipod group) or the more rare and aberrant
Caprellidea; they are less typically scavengers. The large, dark-purple Themisto
libellula is the commonest of these planktonic hyperiids, and perhaps one of
the most important forms in the whole of the Arctic, in any habitat, terrestrial
or aquatic. It appears to replace in many ways of the euphausiids in arctic water,
and is a key species between the smaller planktonic Crustacea (especially the
copepods) and the fish and sea mammals (13). In Canadian eastern arctic waters,
and probably over the whole Arctic, it is the most important single food item
of the ringed seal, and is also eaten in quantities by the arctic char. But
essentially an animal of polar water, it is much less abundant in the subarctic
mixed-water region. It is often found at the surface of the water in the
brightest of sunshine, which is rare among planktonic animals and which is
perhaps made possible by the dark pigmentation; in general it seems to have
a vertical optimum noticeably higher in the water than the rest of the zoo–
plankton. Its food consists largely of copepods and detritus. MacGinitie
( in litt. ) describes Themisto libellula as being washed up on the beach in
summer at Point Barrow in great abundance.

EA-Zoo. Dunbar; Plankton

Other common hyperiids of the arctic and subarctic are Hyperia galba ,
H. medusarum , and Hyperoche medusarum . All three are normally found in
somewhat deeper water than Themisto libellula , and they are also of wider
distribution horizontally, being found in the North Atlantic and North Pacific
as well as in polar water.
Of the gammarid amphipods, the commonest in the coastal waters of the
North are Pseudalibrotus littoralis and Gammarus locusta. G. locusta is
essentially a littoral animal, but it is frequently caught in plankton nets
in fjords and along the coast; it is widely distributed in arctic and northern
temperate regions. Pseudalibrotus littoralis , on the other hand, is almost
confined to arctic water, and in the subarctic belt is normally found only in
the neighborhood of freshwater influxes, close into shore. It has been found
to be the commonest food of the arctic char ( Salvelinus alpinus ) in Frobisher
Bay, Baffin Island, during the months of July and August (E. H. Grainger,
unpublished data). Two common pelagic arctic species are Pseudalibrotus
glacialis and P. nanseni , both restricted to arctic water.
Anonyx nugax is another very common gammarid amphipod of arctic and
boreal seas, found most abundantly in inshore waters. So many gammarids are
normally found in northern seas that it is impracticable to mention them all
in this arcticle; among the more common genera are Acanthonotosoma , Westwoodilla ,
Calliopius , Apherusa , Pontogeneia , Pleustes , Gammaracanthus , and Ischyrocerus .
The caprellid amphipods are represented in arctic and subarctic waters by
the common little “ghost shrimp,” Caprella septentrionalis , present both on
the seaweeds of the littoral and in the water above them.
Cirripeds . The cirriped Crustacea (barnacles) are sessile forms, but the
larvae, both nauplius and cypris stages, are numerous in the epiplankton during

EA-Zoo. Dunbar; Plankton

the early part of the spring-summer season. Balanus balanoides is the most
common species.
Copepods . At most times of year, the copepod Crustaces (order Copepoda)
are dominant in the plankton. In subarctic waters, Calanus finmarchicus
is the most abundant form, replaced to a large degree in pure arctic water
by Calanus hyperboreus , a larger species which may grow up to one centimeter
in length. It is a remarkable fact that Calanus hyperboreus has not been
recorded from Hudson Bay (39); it is, however, scarcely credible that future
and more extensive plankton towing will not show it to be common there. In
deep water (generally below 50 meters in arctic water, much deeper in more
southern regions), Metridia longa often dominates. This species is definitely
arctic in its affinities, and has been found dead in large quantities near
the surface in warmer water (22). Other common copepods in northern regions
are Oithona similis (Pacific, Atlantic, and arctic water); Acartia clause
(Atlantic , and Pacific, and recorded from James Bay and southern Labrador,
but not from East or West Greenland - a most remarkable distribution);
A. longiremus (circumpolar arctic and subarctic); Pleuromamma robusta
(Atlantic boreal,) as far north as Davis Strait); Undinella oblonga (arctic,
less common, carried by undercurrents into the Atlantic); Pareuchaeta glacialis
(arctic predominantly); P. norvegica (Atlantic boreal, mainly in subarctic
waters in our range); Gaidius tenuispinus and G. brevispinus Pacific, Atlantic,
and arctic); Microcalanus pygamaeus (arctic form, spreading down also in
Atlantic and pacific boreal waters, usually in deep water); Pseudocalanus
minutes [: ] (Pacific and Atlantic). The last-named species, which now
includes the form known formerly as P. elongatus , is very abundant, a small
species, and sometimes dominant in the plankton.

EA-Zoo. Dunbar; Plankton

The copepods are of vital importance in the biology of the sea. They
are the chief link in the food net between the phytoplankton and the larger
animal plankton and nekton. To a large extent they feed on diatoms, and
they are themselves the food of many pelagic fish as well as of the right
whales. At times they are so abundant at the surface as to color the whole
area pink or reddish, such swarms consisting usually of Calanus .
Ostracods . The Ostracoda do not form any significant proportion of the
northern plankton. They are sometimes fairly common at the surface, but as
a rule are deepwater forms. The commonest species is Conchoecia superb .
Branchiopods . Of the Branchi o poda, the great majority of which are
freshwater animals, the only group represented in the marine plankton is the
suborder Cladocera, and even in that group there are few marine species. They
appear occasionally in considerable numbers in the surface layers during the
months of July and August.
Annelida
Some of the annelid worms are occasionally caught pelagically as adults,
but in the northern regions there are no annelids whose normal adult habitat
is the free water.
Coelenterata
The a A nthomedusae and Leptomedusae, both of which groups have well-developed
hydroid stages, appear in the plankton only during the spring and summer
months, usually between May and September in the Arctic and Subarctic. The
Trachymedusae, Narcomedusae, and Scyphomedusae, in which the pol y p stage is
much reduced or suppressed, are found during most of the y year, as also are
the Siphonophora and the Ctenophora. It is possible, however, that these

EA-Zoo. Dunbar; Plankton

nonhydroid groups pass at least part of the winter in resting stages, for in
the experience of the writer they are very scarce during the months of Decem–
ber to March in West Greenland. There has been almost no work done hitherto
on the winter distribution and condition of the arctic plankton.
Anthomedusae . Many of the Anthomedusae are extremely abundant in spring
and early summer. Sarsia tubulosa (a species recently revised and rationalized
by Kramp (25) is circumpolar boreal and arctic in distribution; the larger
Sarsia princeps is an arctic water species. Hybocodon prolifer is an Atlantic
species which was found in West Greenland waters by Dr. Paul Hansen in the
1930’s (24). It seems likely that it is a recent immigrant into that area,
following the warming of the West Greenland current during the past thirty
years. The species was also found in large numbers at Lake Harbour, southern
Baffin Island, during July and August 1939 and 1940 (8), so that the intrusion
of Atlantic water into Hudson Strait must be supposed to extend at least as
far as that station. Three North Atlantic species of Euphysa are also
recorded from West Greenland, and the present records from that region con–
tain many other Atlantic immigrants. Bougainvillia superciliaris is a common
arctic and boreal form (both Atlantic and Pacific); B. principis is an
Atlantic form recently found farther north. Rathkea octopunctata and
Leukartiara brevicornis are both Atlantic and Pacific species recorded from
West Greenland and from northern Alaskan waters. Catablema vesicarium ,
C. multicirrata , Halitholus pauper , and H. cirratus are all arctic-boreal
forms, and all of them, except the Pacific Catablema multicirrata , are
circumpolar.
Leptomedusae . The Leptomedusae are less well represented in the North.
Ptychogena lactea is an arctic water, circumpolar form. There are several

EA-Zoo. Dunbar; Plankton

recent arrivals in West Greenland, including Halopsis ocellata , also first
recorded by Kramp (26), and discussed by Jensen (2) in his account of
[: ] climatic changes in West Greenland.
Trachymedusae . Only one of the Trachymedusae can be said to be common,
namely Aglantha digitale , which is arctic and boreal, found in both the
Atlantic and the Pacific. Several distinct races and variants of this
species have been described from various parts of its wide range. There
are a few boreal Trachymedusae which are occasionally found in arctic water and
two arctic bathypelagic species, Ptychogastria polaris and Botrynema ellinorae ,
are also occasionally found in deep Atlantic water.
Narcomedusae. Aeginopsis laurenti is an arctic species, circumpolar in
range. Aeginura grimaldii Aeginura grimaldii is a cosmopolitan deepwater form.
Scyphomedusae . Scyphomedusae are rare in pure arctic water, but in
subarctic areas they are quite common; all of them are fairly widely distri–
buted in temperate regions. Species found in subarctic water include Cyanea
capillata (Atlantic and Pacific), Aurelia limbata (Pacific species),
Halimocyathus lagena and Lucernaria quadricornis (both boreal Atlantic species),
and a few cosmopolitan forms such as Periphylla hyacinthina and Atolla wyvillei ,
both bathypelagic forms (24).
Siphonophora . There is only one species [: ] of siphonophoran at all common
in the North, Diphyes ( Dimophyes ) arctica , an almost cosmopolitan species
found at considerable depths in temperate and tropical regions, and at all
depths in the Arctic. In strongly subarctic regions such as West Greenland,
a variety of boreal species are found as immigrants (27).
Ctenophore. Mertensia ovum is typical of arctic water, and v a e ry common,
Beroë cucumis is a bipolar species . , found in the Arctic and the Antractic,

EA-Zoo. Dunbar; Plankton

and in the deep Atlantic water in between. Bolinopsis infundibulum is an
arctic-boreal species, circumpolar in distribution, but much less abundant
than the other two species.
Protozoa
The protozoa of the arctic and subarctic seas are not at all well
known. For a general review of the planktonic protozoa of the temperate
North Atlantic, the reader is referred to Volume 7 of the periodical Nordisches
Plankton , published in Germany between 1901 and 1913, in which a few species
reported from West Greenland are described. Hardy (17) describes eight
species of the family Tintinnidae (Ciliata) taken by the Nautilus expedition
in 1931, and speaks of them as “a prominent feature of the collection.” They
included five species of Cytharocyclis , Ptychocyclis drygalski (the most
abundant form), Amphorella norvegica , and Tintinnus accuminatum .
No attempt has been made here to supply complete lists of the known
arctic and subarctic planktonic species. Such a list would be long and tedious,
and would serve no useful purpose. Emphasis has been laid on the dominant forms.
Distribution
The plankton can be divided into ( 1 ) true arctic species, and ( 2 ) boreal
or cosmopolitan species whose distribution extends into arctic or subarctic
waters. In the second group, the commoner species are found in both Atlantic
and Pacific; thus the great majority of the species mentioned above are
circumpolar in distribution, and any apparent patchiness in the distribution
of a species is likely to be due to lack of field work. The littoral waters,
over the continental shelf and in fjord regions, are always richer in plankton
than the oceanic regions, due to the greater availability of nutrient materials

EA-Zoo. Dunbar; Plankton

brought to the surface by vertical interchange of water during the winter.
The fact that certain common planktonic species are normally confined
to arctic water has been used to develop a “plankton indicator” technique
for northern regions similar to that developed in other regions. Thus
Frost (15) has shown that six species of the dinoflagellate genus Ceratium
can be used to indicate the presence, in the Newfoundland area, of water of
various types from arctic to Gulf Stream. C. arcticum and C. longipes are
the two cold-water indicators. Similarly Russell (33) gives Diphyes arctica ,
Sagitta maxima , Eukrohnia hamata , Calanus hyperboreus , Metridia longa , and
Limacina helicina as indicators of cold water (mainly but not entirely arctic)
entering the North Sea from the north through the Fair Isle Channel. Themisto
libellula , Pseudalibrotus nanseni , and P. glacialis are useful as arctic water
indicators in most parts of the North.
Distribution is a dynamic, not a static, phenomenon. Nowhere is this
more clearly shown than in the marine plankton, whose distribution is dependent
upon the major water movements and which, therefore, respond immediately to
any changes in the hydrography of a given area. This is particularly well
demonstrated in the waters west of Greenland, where the recent warming of the
water has greatly altered the planktonic fauna; attention is drawn especially
to this fact in the consideration of the West Greenland coelenterates, above.
It is to be regretted that there is no information on the marine plankton of
the Canadian Eastern Arctic before 1939. It is apparent from the plankton
found in Hudson Strait and also in Ungava Bay (unpublished data) that there
is a considerable invasion of Atlantic species in those parts, but it is not
possible, due to the lack of past information, to gauge any changes which
may have [: ] taken place.

EA-Zoo. Dunbar; Plankton

The plankton of the polar sea itself has been studied very little.
Nansen’s expedition of 1893-96 made plankton hauls which yielded a rather
poor plankton, although containing many of the typical species. This was
in the region north [: ] of the Siberian coast and westward to the meridian of
Spitsbergen. Wilkins’ Nautilus submarine expedition in 1931 made plankton
hauls in the upper 100 meters with a No. 25 net (and one haul up from 250 meters
with a No. 10 net) at five stations north of Spitsbergen, along the edge of
the ice between latitude 81° and 82° N. (17). Here again a typical arctic
plankton was found. Russian zoologists have more recently made a study of the
marine plankton north of Siberia, over the shelf, and, in 1937, the Papanin
expedition obtained plankton almost at the North Pole itself, hauling the nets
through the ice (36).
Nansen came to the conclusion that the polar sea was an arctic desert,
containing little or no life (31). This was not confirmed by the Russian
expedition. Hauling their plankton nets from depths as great as 3,000 meters,
they obtained during July and August a considerable variety of plankton,
though not in any remarkable bulk compared to arctic water outside the ice
cover, or to subarctic water. All the commoner copepods were obtained, and
the layer of Atlantic water, underlying the polar water from 250 to 750 meters
in depth, contained typical Atlantic species such as Calanus finmarchicus ,
Microcalanus pygmaeus , Pareuchaeta norvegica , and Oithona similis .
Such a zooplankton must depend on a considerable growth of phytoplankton.
Here again, the Russians upset Nansen’s conclusion. It had been though that
the ice cover of the polar sea, which is three meters thick on the average,
with its light snow layer overlying it, would reduce the light which penetrated
to the water so much that plant life could not exist there, and that the

EA-Zoo. Dunbar; Plankton

phytoplankton growth in the polar sea must be restricted to the open leads in
the ice which open and close from time to time. The Papanin expeditions, how–
ever, found that, although the phytoplankton growth in July was very poor,
there was a considerable flowering in August, by which time the snow cover
had melted and pools of meltwater covered the ice-field surface. The euphotic
zone varied in depth, according to the condition of the ice, from three to
twenty meters. The presence of considerable quantities of phytoplankton
beneath the ice in summer is also recorded at Point Barrow by MacGinitie
( in litt . ), who writes: “Apparently there is some correlation between the
abundance of diatoms and the angle with which the rays of the sun strike the
ice.”
It is interesting that there appears to be only one phytoplankton peak
during the season in the polar basin, occurring in August, and not two separate
peaks in spring and fall, such as are found in temperate waters and also in
subarctic and arctic waters where the ice cover is not permanent all year round.
Such a “monocyclic” condition was also found by Bogorov (4) along the northern
sea route from the Kara Sea to the Chukotsk Sea, accounted for by the very
short period during which light could penetrate into the water.
A well-known characteristic of plankton, both marine and freshwater, is
the diurnal vertical migration performed by the majority of the planktonic
fauna, approaching the surface at night and sinking to lower layers during
the day. It has long been known that light intensity is the dominant factor
in controlling this migration; it was suggested many years ago, first by
Walther in 1893, that the presence of the sun above the horizon at midnight
would inhibit this upward migration of the plankton. Being surprised to find
evidence of diurnal migration in the medusa at Spitsbergen, he attempted to

EA-Zoo. Dunbar; Plankton

to explain it by the hypothesis that they were subarctic forms which had
been carried to Spitsbergen in the Atlantic drift, and that the migration
was due to the persistence of such a physiological rhythm that the habit
of diurnal migration was continued even under conditions of arctic summer
nights.
Russell (34) pointed out that this argument was unconvincing, since
even at that latitude (80° N.) the calculated solar radiation which pene–
trated the surface of the water at midnight in June was only 0.590 gram calorie
per square centimeter per minute, compared to 1.223 gram calories per square
centimeter per minute at noon, which he considered a large enough difference
to account for normal diurnal vertical migration. Bogorov (5) has since pub–
lished his findings in the Barents Sea, in which he finds no evidence of
vertical migra a tion during the height of summer; a little farther south,
however, in the southern part of the White Sea, the normal vertical movement
is apparent, and in September and October the vertical migration has returned
to the plankton in the Barents Sea. Furthermore, he points out that according
to the work of Zubov (41), tidal phenomena in the open sea cause considerable
vertical movement of water particles in the upper layers, so that the mainte–
nance by plankton of a constant level throughout the 24-hour day must entail
considerable swimming activity up and down. This is clearly a most interesting
problem in the biology of arctic plankton, and one which is probably still far
from elucidation.

EA-Zoo. Dunbar; Plankton

BIBLIOGRAPHY

1. Barnes, T. C. “The physiological effect of trihydrol in water,” Nat.Acad.
Sci., Wash., Proc . vol.18, pp.136-37, 1932.

2. ---, and Jahn, T.L. “The effect of ice and steam water on Euglena,
Ibid . vol.19, pp.638-40, 1933.

3. ----, and ----. “Properties of water of biological interest,” Quart .
Rev.Biol . vol.9, no.3, pp.292-341, 1934.

4. Bogorov, B.G. “Biological seasons of the Arctic Sea,” Akad.Nauk.
Comptes Rendus (Doklady) vol.19, no.8, pp.641-44, 1928.

5. ----. “Peculiarities of diurnal vertical migrations of zooplankton in
polar seas,” J.Mar.Res. vol.6, no.1, pp.25-32, 1946.

6. Brandt, K. “Ueber den Stoffwechsel im Meere,” Wissenschaftliche Meeres–
untersuch
. Abt.Kiel , n.s., vol.6, 1899.

7. Dunbar, M.J. “The breeding cycle in Sagitta elegans arctica Aurivillius,”
Canad.J.Res . Ser.D, vol.19, no.9, pp.258-66, 1941.

8. ----. “Marine macroplankton from the Canadian Eastern Arctic. II.
Medusae, Siphonophora, Ctenophora, Pteropoda, and
Chaetognatha,” Canad.J.Res . Ser.D, vol.20, pp.71-77, 1942.

9. ----. “Marine young fish from the Canadian Eastern Arctic,” Canada.
Fisheries Res.Brd. Bull . no.73, 1947.

10. ----. “Note on the delimitation of the arctic and subarctic zones,”
Canad.Field Nat . vol.61, no.1, pp.12-14, 1947.

11. ----. “On the food of seals in the Canadian Eastern Arctic,” Canad.J .
Res . Ser.D. vol.19, pp.150-55, 1941.

12. ----. “On the size distribution and breeding cycles of four marine
planktonic animals from the arctic,” J.Animal Ecol . vol.9,
no.2, pp.215-26, 1940.

13. ----. “On Themisto libellula in Baffin Island coastal waters,” Canada.
Fisheries Res.Brd. J . vol.6, no.6, pp.419-34, 1946.

14. Ehrenbaum, E. “Eier und Larven von Fischen,” Nordisches Plankt . Vol.1,
1905, 1909.

15. Frost, N. “The genus Ceratium and its use as an indicator of hydrographic
conditions in Newfoundland waters,” Newfoundland. Nat.Res.
Dept. Res. Bull . no.5, 1938.

EA-Zoo. Dunbar; Plankton

Bibliography

16. ----, Lindsay, S.T., and Thomposon, H. “Plankton section,” Newfoundland.
Nat.Res.Dept., Fish.Res.Div. Ann.Rep . vol.2, no.1, pp.58-67,
1933.

17. Hardy, A.C. “The arctic plankton collected by the Nautilus expedition,
1931. Part I - General account,” Linnean Soc. J . ( Bot .)
vol.39, pp.391-403, 1936.

18. Harvey, H.W. “On the rate of diatom growth,” Marine Biol.Ass.U.K. J .
vol.19, pp.253-75, 1933.

19. ----. Recent Advances in the Chemistry and Biology of Sea Water.
Cambridge, Engl., Cambridge University Press, 1945.

20. Hesse, R., Allee, W.C., and Schmidt, K.P. Ecological Animal Geography .
N.Y., Wiley, 1937.

21. Jensen, A.S. “Concerning a change of climate during recent decades in the
arctic and subarctic regions,” Danske Vidensk.Selsk.
Biologiske Medd. Vol.14, no.8, pp.1-75, 1939.

22. Jespersen, P. “Godthaab expedition. Copepods,” Medd.Gronland vol.79,
no.10, 1934.

23. ----. “Investigations on the Copepod fauna in east Greenland waters,”
Ibid . vol.119, no.9, 1939.

23a. ----. “On the size of Calanus hyperboreus Krøyer in west Greenland
waters.” Internationale Rev. der Gesamt. Hydrobiol .
u. Hydrogr. vol.34, pp.102-07, 1937.

24. Kramp, P.L. “Medusae, Godthaab Expedition,” Ibid . vol.81, no.1, 1942.

25. ----. “Medusae. Part 2. Anthomedusae,” Danish Ingolf Exped. vol.5,
no.10, 1926.

26. ----. “A revision of the medusae belonging to the family Mitrocomidae,”
Dansk Naturhist.Foren. Copenhagen, Vidensk.Medd . vol.92,
pp.305-84, 1932.

27. ----. “Siphonophora, Godthaab, Expedition, “ Medd.Grønland vol.80, no.8,
1942.

28. Kreps, E., and Verzhbinskaia, N. “Seasonal changes in the phosphate and
nitrate content and in hydrogen ion concentration in the
Barents Sea,” Conseil Perm.Internat.Explor.Mer, J . vol.5,
pp.326-46, 1930.

29. Madsen, H. “Investigations on the shore fauna of east Greenland with a
survey of the shores of other arctic regions,” Medd.Grønland
vol.100, no.8, 1936.

EA-Zoo. Dunbar; Plankton

Bibliography

30. ----. “A study of the littoral fauna of northwest Greenland,” Ibid .
[: ] vol.124, no.3, 1940.

31. Nansen, Fridtjof. The Oceanography of the North Polar Basin . London,
Longmans, 1902. Norwegian North Polar Expedition 1893-96.
Sci.Res . vol.3, no.9.

32. Riley, G.A. “Plankton studies. IIII. Long Island Sound,” Yale Univ.
Peabody Mus.Nat.Hist. Bingham Oceanogr.Fndtn. Bull .
vol.7, no.3, 1941.

33. Russell, F.S. “Hydrographical and biological conditions in the North
Sea as indicated by plankton organisms,” Conseil Perm.
Internat.Explor.Mer, J . vol.14, pp.171-92, 1939.

34. ----. “The vertical distribution of plankton in the sea,” Biol.Rev .
vol.2, pp.213-62, 1927.

35. Ruud J.T. “On the biology of the southern Euphausiidae,” Hvalrådets Skr .
no.2, 1932.

36. Shirshov, P.P. “Oceanological observations,” Akad.Nauk. Comptes Rendus
( Doklady ) vol.19, no.8, pp.569-80, 1938.

37. Sømme, J.D. “Lengievariationer hos Calanus hyperboreus ,” 18de
Skand.Naturforskermøde , Copenhagen, pp.527-28, 1929.

38. Stephensen, K. “Crustacea Malacostraca, 5. Amphipoda (1),” Danish
Ingolf Expedition vol.3, no.8, 1923.

39. Willey, A. “Biological and oceanographic conditions in Hudson Bay.
4. Hudson Bay copepod plankton,” Contr.Canad.Biol. & Fisb .
n.s., vol.6, no.25, pp.483-92, 1931.

40. Wilson, C.B. “The copepods of the plankton gathered during the last cruise
of the ‘Carnegie’,” [: ] Carnegie Inst.Wash. Publ . no.536,
1942.

41. Zubov, N.N. “Gidrologicheskie raboty Morskogo Nauchnogo Instituta v
Iugo-Zapadnoi chasti Barentsova Moria letom 1928 g. na
E/S ‘Persei,’” (Hydrological investigations in the south–
western part of the Barents Sea during the summer 1928.),
Gosudarstvennyi Okeanogr.Inst. Trudy vol.2, no.4, 1932.

Max M . J. Dunbar

Arctic and Subarctic Inverterbrates of Economic Importance

EA-Zoology
(M. J. Dunbar)

ARCTIC AND SUBARCTIC INVERTERBRATES OF ECONOMIC IMPORTANCE

Introduction
Ultimately, all animals in the North may be considered to be of
economic importance, however distantly, since each species plays its part
in the total ecology, of which animals of immediate economic importance
to man form only a comparatively small fraction. But that is not the
significance intended in the title of this article. It is the intention
here to discuss briefly invertebrates in the Arctic and Subarctic which are
either of direct economic value to man, or which play a dominant role in the
biology of animals which are of direct value to man, whether these latter
animals are invertebrate or vertebrate.
In the former group are included certain invertebrates which, although
not at present used economically by Eskimos or others, offer possibilities
of such use in the light of recent knowledge In the latter group, those
of indirect importance to man’s economy in the North, only those of clearly
dominant position are included. Parasites, although obviously important as
disease-producers, are not included; nor are biting flies, although they have
a damaging effect upon human activities in the northern summer, as the recent
Canadian work on their control testifies.

EA-Zoo. Dunbar; Invertebrates of [: ] Economic [: ] Importance

Invertebrates of Direct Economic Value
The deepwater prawn, Pandalus borealis , is by far the most important
animal in this category. Commercial fishing for Pandalus began in Norway,
in 1898, following the exploratory work of Johann Hjort and C. G. J.
Petersen. The fishery continued at a low level until 1920, when it began
to grow rapidly up to over 3,000 tons taken in 1935 (7). On a smaller scale,
prawn fishing was started also in Sweden in 1902, and by Denmark in 1930.
The total weight of prawns landed by all three countries in 1935 was a little
under 5,000 tons. Most of the prawning grounds in Scandinavian waters are
at depths between 60 and 250 meters, but the prawns are found down to much
greater depths.
Experimental fishing for Pandalus borealis in Greenland began in 1934,
in fjords of the Holsteinsborg district on the west coast, and in 1935 a
small cannery was established and was already producing canned prawns.
The production increased to about 70 metric tons by 1939, but was brought
to a temporary stop by wartime conditions. The cannery opened up again after
the war, and exploratory trawling brought to light new trawling grounds in
the Godthaab District, the Julianehaab District, and in Disko Bay. The
latter grounds are perhaps the largest of any known prawn beds. New
canneries have been built at Narssak, in the Julianehaab District, and at
Egedesminde, at the mouth of Disko Bay (4; 5; 6).
The Greenland prawn grounds lie deeper than in Norway, for the most
pa d r t. Most trawling is done at about 400 meters, the deepest trawling bottom
so far found being apparently south of Ata Sound, in Disko Bay, at a depth of
445 metres. As a Norway, the prawns congregate on bottoms of a particular
kind, a firm mud with plenty of detritus; and for good trawling con x d itions the
bottom must of course be free of rocks. The best type of trawling bottom

EA-Zoo. Dunbar; Invertebrates of Economic Importance

will produce a characteristic track on the echo-sounder paper (7), a multiple
tra d c e c d ue to echoes from different layers of mud or sandy mud.
The life history of Pandalus borealis is of special interest. Like
several decap e o d crustaceans, it is a protandric hermaphrodite; each individual,
after a planktonic larval life, goes through a stage of a functional male,
followed by metamorphosis into a functional female stage, in which stage it
remains for the rest of its life. The following account of the Greenland
deepwater prawn is taken (in translation) from Hansen (5):
“…..It is evident that the Greenland prawn, in its life history,
agrees with the deep-water prawn that is found at Spitsbergen, and upon
which the Norwegians have undertaken research work. The eggs which the
female prawn carries on her swimmerets are laid in July and hatch in the summer,
and the young larvae are found in the upper layers of the water. It takes
two years for the larvae to become mature males. They remain as males for
two years, after which time they change sex and become females; they stay
females for the rest of their lifetime. The females are thus older and there–
fore larger than the males. We do not yet know exactly how long they remain as
females, but it is at least two years, so that the prawns live at least six
years altogether. Trawling in Disko Bay has shown that the females lie
farther out from the coast than the males. Trawling near the coast produces
predominantly males and immature young, while trawling some sea-miles from the
land yields femal e s in much larger numbers.”
Pandalus borealis has recently been discovered in large numbers in the
waters of Newfoundland, the Gulf of St. Lawrence, and the Labrador, in depths
over 100 fathoms, the limits of the explored range being Anticosti Island,
southwest Newfoundland, along the northern edge of the Grand Banks, and extending

EA-Zoo. Dunbar; Invertebrates of Economic Importance

(possibly not continuously) up to Nachvak in northern Labrador. It is
possible that they go still farther north on this coast, perhaps into
Ungava Bay; but exploration in the Ungava Bay region has so far not reached
the depths at which Pandalus borealis may be expected, and moreover the
bottom has been found to be very unsuitable for trawling, at least in depths
[: ] down to a hundred fathoms. Furthermore, the temperatures at
these depths in Ungava Bay are below zero Centigrade, probably during the
whole of the summer season, which is somewhat lower than the temperature
range at which Pandalus has been found on the Labrador coast, or in Greenland
waters.
The general known distribution of Pandalus borealis , at present, is as
follows: Pacific and Atlantic oceans; in the Atlantic, from the waters of
Denmark and the Dogger Bank northward to Spitsbergen, where it is found as
far north as Hinlopen Strait and the north of Northeast Land; eastward to
the Barents Sea and in the Kara Sea to 78° 30' E.; Iceland, southeast Greenland,
and up the west Greenland coast to 75° 30' N; from Cape Cod to Nachvak,
Labrador. In the Pacific, it is known from the waters off Japan, in the Sea
of Okhotsk, and from the waters round the Aleutian Islands, along the south
coast of Alaska southward to the mouth of the Columbia River, latitude 46° N.
(7). It has been recorded from Bering Strait, but it is not common in the northern part of the Bering sea, and the known in purely
Bering Strait record (Maud expedition) seems to work the extreme limit of range in arctic water. It is thus a subarctic-boreal form.
that region. It is not known in purely arctic water. It is thus a subarctic-boreal form.
Prawns of other species than Pandalus borealis have been found in
promising numbers in the northern part of the Bering Sea, by a trawling
survey in 1949, sent out by the U.S. Fish and Wildlife Service. The survey
was partly in response to numerous reports from local residents that there
existed in the northern Bering Sea species of animals, from cod to shrimps

EA-Zoo. Dunbar; Invertebrates of Economic Importance

which might have a commercial value. Five species of shrimps or prawns
(the vernacular terms are interchangeable) were caught “mainly in the
waters around St. Lawrence Island and the approaches to Norton Sound.
Considering the large mesh of the trawl used (3″mesh in the bag, 6″ in the wings
and square), the numbers of gray shrimp ( Argis lar ) taken may be considered
sufficient to justify further investigation with g r ear more suitable for
shrimp fishing.” ( 3). The shrimps were caught in depths down to 40 fathoms,
mainly in water of temperatures between 0° and 4°C. Besides Argis lar , the
following four species were taken: Pandalus gonirus , P. hypsinotus , Spiron–
tocaris
groenlandica , and Sclerocrangon boreas .
The same Bering Sea survey in 1949 [: ] studied the occurrence of king
crabs ( Paralithodes — not to be confused with the totally different Atlantic
“king crab,” Limulus, which is an arachnid, not a crustacean). King crabs
are at present fished commercially in the southern part of the Bering Sea.
In the northern part, “King crabs were widely scattered and of a much
smaller size than those found to the south. Both the Alaskan and purple
species were taken, and although no great quantities were found, it is
possible that a more thorough survey might reveal areas of concentration.
The shoal conditions in the northern area make it difficult to predict crab
movements there on the basis of knowledge gained in the southern regions of
deeper waters.” (3). The two species found were Paralithodes camtschatica
and P. platypus . They were taken in shallow water only, in depths down to
30 fathoms, and most of them were found at temperatures between 0° and 4° C.
Only 100 specimens were taken in the 51 drags made.
The deepwater prawn is the only invertebrate at present exploited
commercially in northern waters, and it is not itself a truly arctic form.

EA-Zoo. Dunbar; Invertebrates of Economic Importance

The prawns and king crabs taken in the northern Bering Sea may offer
possibilities of future use; they too are not arctic water forms, and
are not found in water of negative temperature. Arctic water itself,
then, by which is meant water originating in the Polar Sea and not mixed
with temperate waters, has so far not produced any commercial fishing for
invertebrates. Nor in fact does it offer many fishes in sufficient numbers
for such exploitation. The only invertebrate that is used to any extent
as food by the Eskimos, namely the blue mussel, Mytilus edulis , is also a
subarctic-boreal animal, not found in pure polar water.
Mytilu m s edulis is circumpolar in distribution, from the northern limits
of the marine Subarctic southward in the Atlantic and Pacific to San Fran–
cisco on the American Pacific coast, North Carolina on the Atlantic side,
and the coast of Portugal in western Europe. In the north, it is one of the “indicator” littoral species by which a good estimate of
the limits of influence of nonarctic water can be made (2; 8; 9; see also
“Littoral Fauna” in this Encyclopedia). It shows a gradient of abundance,
decreasing northward. It is known as far north as Thule in West Greenland,
and it is found along the Labrador coast and in Ungava Bay. It is not common
in Ungava Bay, except at Port Burwell, where there is a bed exposed at spring
tides which is made use of by the native population. Wherever it occurs it
occurs in any numbers, it is eaten by the Eskimos as a pleasant change
in diet, and a very healt h y one. Sometimes whole meals of blue mussels are
eaten, especially in areas of abundance in West Greenland.
Other invertebrates are of much less importance to the Eskimos. Shrimps,
whelks ( Littorina — also a subarctic and boreal form) and the ovaries of
the sea urchin ( Strongylocentrotus ) are occasionally eaten when casually
picked up, or when starvation threatens, but they are of very minor signify–
cance. In subarctic areas, similar to those in which Mytilus is found in

EA-Zoo. Dunbar; Invertebrates of Economic Importance

the North, Littorina is very abundant in summer, and although small in size
could be eaten in greater quantities than is the fact at present.
In periods of great threat of starvation, when in fact di s aster threatens,
invertebrates have figure s d in the diet of several expeditions. The best
example of this was the Greely expedition to Ellesmere Island, one of the
first International Polar Year parties, in 1882-83. During the last stages
of exhaustion, when the relief ship had failed to appear, Greely’s diary
records that “shrimp” were caught in a net, at the surface of the water,
and carefully rationed among the survivors. The cook was caught stealing
these “shrimps,” and on repeating the offence after due warning, was shot;
a good instance of the vital importance, on one occasion, of invertebrates
in the Arctic. These animals were taken in pure arctic water, close to the
surface, and it is probable that they were in fact Themisto libellula , an
amphipod crustacean of great abundance in arctic water, and one of the very
few forms found at the surface in large numbers. It is also possible that
the animals concerned were Gammarus locusta .
Invertebrates of Dominant but Indirect Economic Importance.
This section will be covered only very briefly. In arctic and subarctic
environments, particularly marine environments, there are invertebrate forms
so dominant in the animal populations that they form almost exclusive diets
for larger animals, at least during certain seasons. The following list
includes only those animals that fall into this category, very often forming
monospecific populations locally, sometimes over wide areas, and thus figuring
as the direct support of animals of economic value to man: The amphipod
crustacean Themisto libellula , Anonyx nugax , Pseudalibrotus littoralis ,

EA-Zoo. Dunbar; Invertebrates of Economic Importance

Gammarus locusta , and (in fresh water) Pontoporeia affinis ; the euphausiids
Thysanoessa raschii and T. inermis , and Meganyctiphanes norvegica ; the mysids
Mysis oculata and (in fresh water) Mysis relicta ; several copepods, more
especially Calanus hyperboreus , C. finmarchicus and Metridia longa ; and the
mollusk Limacina helicina .
All these are “key industry” or dominant species in their respective
ecological territories. Themisto libellula is an upper - water form, deeply
pigmented and apparently able to tolerate the direct rays of the sun at the
surface. It is the most important of all food organisms of the ringed seal,
Phoca hispida (1). Seal stomachs are often found to be entirely filled with
nothing else but Themisto . It has also been found frequently in the stomachs
of the harp seal, Phoca groenlandica , and of the arctic char, Salvelinus
alpinus , and it is important in the food of sea birds in the Arctic. As a
link between the smaller planktonic crustaceans and the larger predators it
is perhaps the most important animal in the North, in any environment. Like
all the other animals in the present list, it is circumpolar in distribution.
Anonyx nugax , another abundant form in both the plankton and the
littoral fauna, is found in deeper water than Themisto , except in the littoral
zone, where Themisto does not occur. It is eaten in large numbers by inshore
fishes and also plays an important part in the marine diet of the arctic char.
Even more numerous than Anonyx is Pseudalibrotus littoralis , which is
present in enormous numbers in shallow water all over the northern seas.
Skulls and other skeletal specimens which the present writer has lowered to
the bottom for cleaning purposes in Ungava Bay, have been hauled back on board
ship completely filled with this amphipod. It has been found to be by far the
common food of the arctic char in Frobisher Bay (Grainger, unpublished
data: see “Arctic C h ar”).

EA-Zoo. Dunbar; Invertebrates of Economic Importance

Gammarus locusta , the ubiquitous littoral amphipod, is abundant on
arctic and subarctic shores, and figures in the normal diet of all inshore
fishes. It is eaten in great numbers by the Atlantic cod ( Gadus callarias )
in West Greenland and in Ungava Bay (Port Burwell), and is also eaten by
the arctic char.
Pontoporeia affinis is perhaps the most common amphipod in freshwater
environments in the northern regions, and as such is of great importance as
the main food of ma h n y freshwater fishes of considerable economic importance,
such as the whitefishes and lake herrings.
The three euphausiids, Meganyctiphanes and two species of Thysanoessa ,
collectively known by the vernacular Norwegian name of krill , are pelagic
forms found in large numbers over a wide depth range. They are not usually
found very close to the surface, and thus do not complete with Themisto for
dominance. They have been found in the stomachs of sea birds (eider duck,
old squaw, kittiwake, murre, etc.), and form one of the chief foods of the
capelin ( Mallotus villosus ), and of the harp seal in certain parts of the
North. They are perhaps best known of all as the food of the blue whale
( Balaenoptera musculus ), and to a lesser extent of the other rorquals
(finback, Balaenoptera physalus ; sei whale, B. borealis , etc.).
Mysis oculata is frequently met with in large schools or swarms in
shallow water, often where fresh water flows into the sea. It keeps as
a rule fairly close to the bottom. It is locally important in the food of
the Atlantic cod, the capelin, and the ringed, harp. And harbor seals.
The freshwater relict form of Mysis oculata is M. relicta , very common
in many lakes.
The copepod plankton form the chief link between the phytoplankton and
the larger zooplankton, and also form the food of larger animals of great

EA-Zoo. Dunbar; Invertebrates of Economic Importance

economic worth, such as the right whales ( Balaena spp.) and the herring
( Clupea harengus ). The dominant forms in the North are Calanus finmarchicus
and C. hyperboreus , together with a few other genera such as Metridia ,
Oithona , and others. (See “Marine Plankton”)
The little “sea butterly,” Limacina helicina , appears in vast numbers
in the surface waters of the Arctic in August and September. In northern
Labrador and at Port Burwell, Ungava Bay, it figures prominently in the
food of the Atlantic cod. On the Labrador, in fact, the fishermen speak of
“capelin cod” in the southern half of the coast, where capelin form the
bulk of the cod diet, and “blackberry cod” in the northern part of the coast,
“blackberry” being another vernacular name for Limacina. Limacina has also
been taken in numbers from the stomachs of ringed seal at Clyde River, Baffin
Island, in September, at a time of year when there is very little else in the
plankton for the seal to feed upon, at least in the surface layers of the
[: ] fjord waters (1). At one time it was thought that
the occasional bad taste of seal meat, and the poisonous qualities of polar
bear liver, were referable to the habit of the seal in eating Limacina ; but
the dangers of eating polar bear liver are now known to be due to factors for
which it seems quite unreasonable to blame this apparently harmless little
mollusk. The codfish in Labrador and Ungava Bay waters, which eat Limacina ,
are perfectly wholesome food.

EA-Zoo. Dunbar; Invertebrates of Economic Importance

BIBLIOGRAPHY

1. Dunbar, M.J. “On the food of seals in the Canadian eastern arctic.”
Can.J.Research , D, vol.19, pp.150-55, 1941.

2. ----. “Note on the delimitation of the arctic and subarctic zones.”
Can.Field-Nat ., vol.61 (1), pp.12-14, 1947.

3. Ellison, J.G., Powell, D. E. and Hildebrand, H. H. “Exploratory
fishing expedition to the northern Bering Sea in Juna and
July, 1949.” U.S.Dept. Interior; Fish & Wildlife Service,
Fishery Leaflet No. 369; 56 pp., mimeographed, 1950.

4. Greenland Administration. “Sammendrag af Statistiske Oplysninger
om Grønland, IV, 20 Afsnit: Henkogningsstationen ved
Holsteinsborg.” Beretn.vedr.Gronl.Styrelse , no.1, pp.709-16,
1945.

5. Hansen, P. M. “Fiskeriundersøgelserne ved Grønland.” Grønlandposten ,
vol.8, (8), pp.98-102, 1949.

6. ----. “Dybhavsrejen ved Grønland.” Grønlandposten, vol.8 (3), pp.26-30,
1949.

7. Hjort, J., and Rund, J. T. “Deep-sea prawn fisheries and their problems.”
Hvalradets Skrifter , no.17, pp.1-144, 1938.

8. Madsen, H. “Investigations on the shore fauna of east Greenland with
a survey of the shores of other arctic regions.” Medd.Grøn .
vol.100 (8), pp.1-79, 1936.

9. ----. “A study of the littoral fauna of northwest Greenland.”
Medd.Grøn . vol.124 (3), pp.1-24, 1940.

10. Rasmussen, B. “Om Dypvannsreken ved Spitsbergen.” Rep. Norwegian
Fish. & Mar. Investigations , vol.7 (4),

M. J. Dunbar

Marine Fishes of the North American Arctic

EA-Zoology (Henry Hildebrand)

MARINE FISHES OF THE NORTH AMERICAN ARCTIC

CONTENTS
Page
Hydrographic Conditions 2
Ichthyofauna 4
Summary 16
Bibliography 17

EA-Zoology
(Henry Hildebrand)

MARINE FISHES OF THE NORTH AMERICAN ARCTIC
Our knowledge of the fish fauna of the American Arctic is very limited,
and there is need for much additional work before a clear picture of the
fauna can be drawn. Even today there are no commercial fisheries in the area
except in West Greenland. Early explorers were primarily interested in find–
ing a short route to the riches of Cathay, searching for precious minerals,
or attempting to reach the North Pole; any zoological exploration was merely
incidental and was not prosecuted vigorously.
An immense area is covered by this article — all of the Arctic Sea
between the longitudes of Cape Farewell, Greenland, and Bering Strait, and
all the marine waters north of the coast line of continental North America
including James Bay, which reaches south to approximately 51° N. latitude.
Demark has consistently held the lead in arctic scientific exploration.
In fisheries, the brig Tjalfe was outfitted by the Danish Government for in–
vestigations in Greenland during the years 1908-09; Adolph S. Jensen was the
leader of this expedition. Among other important fisheries investigations
in Greenlandic waters was that of the Dana in 1925. Canada has long been aware
of the vast Hudson Bay, which extend s so deeply southward into her territory.
Several expeditions have been sent here, the latest and best equipped being
the Loubyrne fisheries expedition in 1930.

EA-Zoo. Hildebrand: Marine Fishes of American Arctic

A new interest has been manifested in this region in recent years, in
part due to changing hydrographic conditions which have revitalized the
fishing industry of Greenland, in part to unsettled world conditions. A
decline in land and sea mammals coupled with increasing native populations
have incited a greater interest in the ichthyofauna of the seas as a means
of bettering living conditions. The Canadian Government has had an expedi–
tion in Ungava Bay for the past four summers (1947-50) for this purpose.
Several new ships have been built for arctic marine research: the Adolph S .
Jensen by the Danes, the Calanus by the Canadians; and the Ernest Holt by the
British.
The literature concerning arctic fishes is not great and is widely
diffused in numerous small articles and in narratives of travel and explora–
tion. A list of impotant references is given at the end of this article.
The writer wishes to acknowledge his indebtedness to the curators of the
following fish collections: National Museum of Canada, Royal Ontario Museum
of Zoology, Chicago Museum of Natural History, United States National Museum,
and the McGill University collections, for permission to examine specimens
from the Arctic.
Hydrographic Conditions
A brief r e é sum e é of hydrographic conditions will help to explain the
distribution of fishes. However, it must be admitted that much hydrographic
investigation remains to be done, whole areas being relatively unexplored.
Pacific Influence . The status is not clearly defined, but the term refers

EA-Zoo. Hildebrand: Marine Fishes of American Arctic

to the warming effect of Pacific water entering through Bering Strait and
progressing eastward at least to the Mackenzie.
Mackenzie District . This term is used to define the area where large
rivers flow into the Arctic Sea; it extends eastward to Back River.
Arctic Archipelago ( Including Boothia Peninsula ). This area is char–
acterized for the most part by poor circulation, heavy and continued icing
for most of the year, and a very limited fauna.
Hudson Bay and Strait . This region is characterized by low temperature
and salinity, and well-stratified water layers with little vertical movement.
Baffin Bay and the East Coast of Baffin Island . This area is charac–
terized by the cold Arctic Current from Lancaster Sound.
West Greenland . This is the area south of the submarine ridge across
the narrowest part of Davis Strait between Greenland and Baffin Island, which
is warmed by the West Greenland Current and has a bottom temperature of at
least 3°C.
Transition Areas . There is some mixture of Atlantic water north of the
submarine ridge, which permits some forms to migrate farther north, especially
during the summer months. There is a modified influence of Atlantic water
around Port Burwell in Ungava Bay, with a change of fauna. Extreme south–
western Greenland is cooled by the East Greenland Current and is relatively
arctic in affinities.
It must be remembered that distribution of organisms is not a static
but a dynamic phenomenon. Jensen, in 1939, showed how a slight warming of
the West Greenland Current had so changed the fish fauna in Davis Strait as
to alter the economy of the Greenlanders during the two preceding decades.

EA-Zoo. Hildebrand: Marine Fishes of American Arctic

Ichthyofauna
A brief review of the ichthyofauna of the American Arctic will be given,
including each individual species known to occur in the region. However, it
must be stated that many arctic forms are in a state of chaos taxonomically,
because of lack of specimens and the marked inadequacy of original descript–
tions. Classification as used herein was taken from Jordan, Evermann, and
Clark, Checklist of the Fishes and Fishlike Vertebrates of North and Middle
America (1930), except where recent publications indicate a change. The
writer has also referred to a number of monographs on individual groups by
Ad. S. Jensen for names of forms occurring in Greenland.
Myxine glutinosa (hagfish): not uncommon in the deep water of Davis
Strait warmed by the West Greenland Current.
Petromyzon marinus (sea lamprey): rare, specimens known from South
Greenland.
Squalus acanthias (common dogfish, spiny dogfish): formerly rare and
irregular in occurrence; Jensen states that this species has become more
common along the west coast of Greenland due to a recent amelioration of
climate.
Centroscyllium fabricii (black dogfish): a deep-water form occurring
in the “warm” water south of the submarine ridge in Davis Strait.
Somniosus microcephalus (Greenland shark): common along the west coast
of Greenland from Cape Farewell to Wolstenholme Sound. Other definite locali–
ties are Port Burwell and the Koksoak River estuary in Ungava Bay. Sight
records are known from Wakeham Bay, Hudson Strait, Southampton Island, and
several localities along the east coast of Hudson Bay, south to Great Whale
River.

EA-Zoo. Hildebrand: Marine Fishes of American Arctic

This ground shark is a great carrion eater and will probably eventually
be found to parallel the distribution of the larger sea mammals in the Arctic.
It is an important economic fish to the Greenlanders; oil was first extracted
from the livers in 1805, and during the twentieth century the skins have
been added as an article of commerce. Nearly 35,000 sharks are taken yearly
by the Greenlanders, who regularly fish for this large, sluggish animal from
kayaks and also on fast ice. It offers little resistance when hooked.
Although numerous specimens of this shark have been taken, its mode of
reproduction is unknown. The consensus is that it bears its young a b live,
but this has yet to be proved.
The meat of the shark when dried is used as dog food, and if necessity
decress, human food. Fresh shark meat makes dogs violently ill, producing
what is known as “shark intoxication.” Death may ensue from eating the
fresh meat.
Raja radiata : not uncommon along the west coast of Greenland north to
approximately 69° N. latitude. One specimen from Richmond Gulf, Hudson Bay,
is known.
Raja fyllae : not uncommon in deep water south of the submarine ridge in
Davis Strait.
Raja hyperborea : inhabits the deep cold water north of the submarine
ridge and has also been reported from extreme southwestern Greenland.
Raja lintea : common in the deep “warm” water of Davis Strait.
Raja spinicauda : distribution same as preceding species, but not as common.
Acipenser fulvescens (sturgeon): primarily fresh water, occurs in the
brackish river mouths of James Bay.

EA-Zoo. Hildebrand: Marine Fishes of American Arctic

Clupea harengus (common herring): formerly not common in West Greenland,
although fluctuations in numbers undoubtedly occurred. In recent years,
herring have increased in numbers and have almost become of economic impor–
tance. In 1934, two large herring were taken at Prőven, Greenland, in lati–
tude 72°30' N.
Clupea pallasii (California herring): migrates sporadically into the
Arctic from the Pacific, reported as far east as Bathurst Inlet. Anderson
(1913) records a large school which appeared at Cape Bathurst in August 1911.
Oncorhynchus gorbuscha (humpbacked slamon): straying along the north
coast of Alaska at least to the Mackenzie River.
Oncorhynchus kets (dog salmon): straying through Bering Strait at least
to the Mackenzie. In 1914, a large run of salmon up the Mackenzie River was
reported.
Salmo salar (Atlantic salmon): common only in the rivers of southern
and eastern Ungava Bay; uncommon in Greenland, reported only from Godthaab
Fjord, Amerdloq Fjord near Holsteinsborg, and Ikerasak, Sukkertoppen District.
This is the only fish in the Canadian Arctic ever to have supported a
sustained commercial fishery. It was shipped direct to London markets from
Ungava Bay for a number of years, starting in 1881 and continuing until the
failure of the fishery in 1932. The number caught was not large, but varied
between 150 to 300 tierces a year.
Salvelinus fontinalis (brook trout): primarily a freshwater form, but
has been reported from brackish and salt water in southern Ungava Bay, James
Bay, and Hudson Bay, at least as far north as the limit of trees.
Salvelinus alpinus (arctic char, arctic salmon, or salmon trout):

EA-Zoo. Hildebrand: Marine Fishes of American Arctic

anadromous and abundant throughout the Arctic; taxonomic status confused,
but all species described or reported from this region are included under
alpinus pending clarification of its taxonomic status. The fish is known
by a number of common names; in fact, it varies so much according to age or
ecological habitat that many explorers and travelers have though they were
dealing with separate species.
This is the ekaluk of the Eskimo and the most important food fish through–
out much of the Arctic. Nowhere has it been developed commercially except
in Greenland, where a few hundred barrels a year are exported to Denmark.
Stenodus leucichthys (inconnu): anadromous and common in the Mackenzie
River and tributaries; its eastern limit has been cited as Anderson River,
and to the west it extends along the arctic coast of Alaska.
Leucichthys autumnalis : primarily a freshwater form, occurs along the
arctic coast of Alaska to the Mackenzie.
Leucichthys sardinella : range similar to preceding species.
Leucichthys artedi (cisco): occurs in brackish water from Ungava Bay to
the Mackenzie; distribution along the arctic coast of Canada poorly known. In
Hudson Bay ciscoes are known to migrate to salt water during the summer.
Coregonus clupeaformis (common whitefish): primarily in fresh water, occurs
sparingly to commonly in the brackish water of Ungava, James, and Hudson bays
and probably the estuaries of the larger rivers along the arctic coast to the
Mackenzie. In Hudson Bay, whitefish are known to migrate to salt water during
the summer.
Prosopium cylindraceum (round whitefish): distribution similar to preceding
species, but makes a very unsatisfactory growth in the northern part of its Hudson
Bay range.

EA-Zoo. Hildebrand: Marine Fishes of American Arctic

Mallotus villosus (capelin): possibly, when specimens are available,
two species will be found to occur in the Arctic. Capelin are common along
the west coast of Greenland and reach latitude 76°30' N. in migration.
Records are known from Ungava Bay, James Bay, Foxe Basin, Bellot Strait,
Coronation Gulf, Bathurst Inlet, and Point Barrow. Occurrences are often
sporadic. In parts of Greenland this form is caught and dried and is known
as the “daily bread” of the Greenlanders.
Osmerus dentex (smelt): rare at the mouth of the Mackenzie River and
along the Alaskan coast.
Nansenia groenlandica : rare in the deep water of Davis Strait.
Bathylagus benedicti : deep water of Davis Strait south of the submarine
ridge.
Stomias boa : deep “warm” water of Davis Strait, straying to Jacobshavn.
Cyclothone microdon : deep water of Davis Strait, straying into Baffin Bay.
Argyropelecus olfersi : rare in the deep water of Davis Strait.
Notacanthus chemnitzi : rare in the deep water of Davis Strait.
Notacanthus rostratus : rare in the deep water of Davis Strait.
Anguilla bostoniensis (= A. rostrata ) (American eel): six specimens known
from southwest Greenland in the neighborhood of Nanortalik.
Synaphobranchus pinnatus (long-nosed eel): not uncommon in the deep “warm”
water of Davis Strait.
Histiobranchus infernalis : deep water of Davis Strait.
Saccopharynx ampullaceus : very rare, one specimen known from the entrance
of Davis Strait.
Paralepis conregonoides borealis : known from the west coast of Greenland
from Cape Farewell to Umanak Fjord in latitude 72° N. This form does not breed

EA-Zoo. Hildebrand: Marine Fishes of American Arctic

in the area, and is probably carried into the region by the current. It is
usually taken dead on the surface, or from fish or seal stomachs.
Paralepis risso kroyeri : range similar to preceding species, but very
rare; known from Greenland by only five specimens; also recorded from Port
Burwell, Ungava Bay.
Lampanyctus crocodilus (lantern fish): bathypelagic, common south of
the submarine ridge in Davis Strait; also reported from Port Burwell.
Lampanyctus elongates (lantern fish): rare and of doubtful occurrence;
reported from Godhavn, Greenland.
Myctophum arcticum (lantern fish): bathypelagic; known from Davis Strait.
Myctophum glacialis (lanter n fish): bathypelagic; common south of the
submarine ridge in Davis Strait. This lanter n fish has also been recorded from
Baffin Bay and Port Burwell, Ungava Bay.
Alepisarus ferox (lancet fish): deep water of Davis Strait and also
reported from Jacobshavn, Greenland.
Coryphaenoides rupestris (grenadier): common in the deep water of Davis
Strait and also in the fjords of West Greenland.
Macrourus aequalis (grenadier): rare in Greenlandic waters.
Macrourus berglax (rattail grenadier): a very common macrourid in the
deep water of Davis Strait.
Macrourus goodei : rare in our region; known from two specimens taken near
the entrance of Davis Strait.
Trachyrhynchus murrayi : known from a single specimen from the west coast
of Greenland.
Gaidropsa r us ensis : deep water and rare; reported from Umanak, Greenland.

EA-Zoo. Hildebrand: Marine Fishes of American Arctic

Gaidropsarus septentrionalis : rare in the deep water of Davis Strait.
Ciliate argentata : This species has been taken in the deep water on
both sides of the submarine ridge in Davis Strait.
Boreogadus saida (arctic Pollack, polar cod): a common fish throughout
the Arctic. This is a pelagic salt-water form, which is often found among the
ice floes. When pursued by the white whale, this fish has been known to
leap upon the ice floes in its endeavor to escape.
Recent studies indicate that there may be several species occurring
in the American Arctic. Arctogadus pearyi and B. agilis have been reported
from Greenlandic waters, but their status is very uncertain due to the lack
of comparative specimens.
Pollachius virens (coalfish): formerly rare in West Greenland waters;
however, with the recent amelioration of climate, large shoals have been
seen in the south Frederikshaab district.
Eleginus navaga (tomcod): This form has been reported from the Mackenzie
Delta, Bering Sea, Point Barrow, Simpson Strait, and Coronation Gulf. In–
formation on this species is very scanty.
Cadus callarias (common Atlantic cod): This fish has known periodic
cycles of abundance in West Greenland, which are apparently associated with
climatic changes. Jensen (1939) outlines how a recent climatic change has
so increased the number of cod as to alter the entire economy of the Green–
landers. Specimens have been taken as far north as Upernivik in Greenland.
The fish regularly spawns in Greenland waters. Cod occur at Port Burwell,
Ungava Bay, during the months of August and September.
Gadus ogac (Greenland cod): This is a northern species of cod; it

EA-Zoo. Hildebrand: Marine Fishes of American Arctic

prefers rocky grounds and coastal salt water. It has been reported from many
points in West Greenland, also Ungava Bay, Hudson Bay, Adelaide Peninsula,
Victoria Island, and Kent Peninsula. Apparently it has not been recognized in
Alaskan waters.
Melanogrammus aeglefinus (haddock): very rare; apparently recorded for
the first time in 1929 in West Greenland.
Molva molva : very rare; reported from the Frederikshaab District of
Greenland.
Brosmius brosme (cusk): a rare form in the area warmed by the West Green–
land Current.
Trachypterus arcticus (deal fish): straying into the region warmed by
[: ] the West Greenland Current.
Lampris guttatus : a rare fish in Greenlandic waters.
Reinhardtius hippoglossoides (Greenland halibut, arctic halibut): a common
and economically important fish along the west coast of Greenland to Umanak in
the north. This fish does not spawn in the bays and fjords where the adults
occur, but out in Davis Strait over deep water. Small specimens have been
taken at Port Burwell.
Hippoglossus hippoglossus (Atlantic halibut): common along the west coast
of Greenland; has been fished as far north as Umanak, and a few strays have
been taken at Upernivik.
Hippoglossoides platessoides (sand dab): occurs along the west coast of
Greenland to Umanak in the north.
Platichthys stellatus (California flounder): This species has been re–
ported from Langton Bay, Kittigazuit, Coronation Gulf, and Queen Maud Gulf in
the Northwest Territories.

EA-Zoo. Hildebrand: Marine Fishes of American Arctic

Liopsetta glacialis (arctic flounder): This species is reported from
Bathurst Inlet, Bernard Harbour, and Queen Maud Gulf in the Northwest Ter–
ritories. The arctic flounder, like the preceding species, has no economic
importance in the Arctic.
Glyptocephalus cynoglossus (witch flounder): reported from Davis Strait
south of the submarine ridge.
Gasterosteus aculeatus (three-spined stickleback): common in small brackish
water streams throughout the Arctic, except the extreme north.
Pungitius pungitius (nine-spined stickleback): common throughout most of
the Arctic except Greenland. It does not occur in the brackish streams in
Greenland.
Sebastes marinus (rose fish): This fish occurs along the coast of Greenland
from Cape Farewell to 71° N. latitude; a deep-water fish of commercial importance
in Greenland. Two small specimens have been reported from Port Burwell.
Artediellus uncinatus (hook-eared sculpin): reported from Davis Strait
in deep water, also Dolphin and Union Strait in the Northwest Territories.
Icelus bicornis (two-horned sculpin): This species probably occurs through–
out the Arctic; however, it has been reported only from West Greenland, southern
Ellesmere Island, Jones Sound, Hudson Bay, Foxe Basin, and Dolphin and Union
Strait.
Triglops pingeli (mailed sculpin): This sculpin has been recorded from
Dolphin and Union Strait, Hudson Bay, Ungava Bay, and the entire west coast of
Greenland. This is a deep-water sculpin although occurring in shallow water
in the northern part of its range.

EA-Zoo. Hildebrand: Marine Fishes of American Arctic

Triglops nybelini : a high-arctic sculpin occurring in Greenland to 78° N.
latitude, and apparently inhabiting deeper water than T. pingeli .
Myoxocephalus scorpius (common sculpin): This is a common littoral sculpin
and is rarely taken below 30 meters. It is abundant along the west coast of
Greenland, north to Thule, where it is replaced by Oncocottus quadricornis .
In Ungava Bay this is the commonest shore sculpin. While M. scorpius has been
reported from James Bay, Hudson Bay, Foxe Basin, Dolphin and Union Strait, and
Devon Island, it is not as common in those regions as O. quadricornis .
Myoxocephalus scorpiodes : This is a small littoral sculpin closely re–
sembling M. scorpius , reported as far north as Etah along the west coast of
Greenland. It is common in James and Hudson bays, living in the littoral zone.
Although reported from Foxe Basin and Dolphin and Union Strait, this form is
evidently rare along the coast of arctic Canada, and is apparently unknown
from Alaskan waters.
Porocottus polaris : a small cottoid, whose affinities are unknown, reported
from Melville Island and Boothia Peninsula.
Oncocottus quadricornis (four-horned sculpin): a high-arctic littoral
sculpin replacing M. scorpius in Greenland, north of Thule; often used as an
indicator of high-arctic waters. This sculpin is known from the north coast
of Ellesmere Island and holds the farthest north record of a marine fish.
Along the arctic coast of North America, this is much commoner than M. scorpius .
Gymnocanthus tricuspis (stag-horned sculpin): a common sculpin along the
coast of Greenland north to Etah; also known from Jones Sound, east Baffin
Island, Ungava Bay, Hudson Bay, and Foxe Basin. The Pacific form G. galeatus
was identified from Hudson Bay on the basis of a single specimen.

EA-Zoo. Hildebrand: Marine Fishes of American Arctic

Gymnocanthus pistilliger : known from the northern coast of Alaska to
Dolphin and Union Strait.
Cottunculus microps : deep water of Davis Strait on both sides of the
submarine ridge.
Cottunculus thompsonii : rare in the deep water of Davis Strait.
Leptagonus decagonus : common in Greenlandic waters north to Smith Sound
on the west coast; also reported from Exeter Sound and Lake Harbour, Baffin
Island.
Aspidophoroides monopterygius (sea poacher): along the coast of Green–
land from Ivigtut to Jacobshavn, and from Exeter Sound, Baffin Island.
Aspidophoroides olriki : common along the coast of West Greenland from
67° to 71° N. latitude; elsewhere reported from Ungava Bay, Hudson Strait, and
Hudson Bay.
Cyclopterus lumpus (lumpfish): common in the southern part of its range
along the coast of Greenland from Cape Farewell to Umanak; also reported
from James Bay and the Churchill district of Hudson Bay.
Eumicrotremus spinosus (spiny lumpfish): common along the entire west
coast of Greenland to Etah; also reported from Ungava Bay, Hudson Strait and
Hudson Bay, and Foxe Basin.
Eumicrotremus derjugini : recognized only from Hudson Bay.
Cyclopteropsis malcalpini : known from type locality, Ulrik Bay, Greenland.
Lethrotremus armouri : known only from Upernivik, Greenland.
Liparis spp. (sea snails): Considerable confusion exists concerning the
systematic position of the liparids in northern waters. L. atlanticus has
been doubtfully identified from Ungava Bay. L. tunicatus is common along the

EA-Zoo. Hildebrand: Marine Fishes of American Arctic

coasts of Greenland, Ungava Bay, Cumberland Sound, Foxe Basin, and Jones
Sound. L. major is known from Greenland north to Etah. L. cyclostigma , a
Bering Sea species, is known only from Hudson Bay in our region.
L. herschelinus is known from Alaska and Herschel Island, Northwest Ter–
ritories.
Careproctus reinhardti : a deep-sea fish which has been reported
from Umanak and Jacobshavn, Greenland.
Ammodytes lancea (sand launce): a common fish from Julianehaab dis–
trict to Umanak, Greenland. This species had also been reported from Ungava
Bay, Hudson Bay, and Kent Peninsula, Northwest Territories. A number of
subspecies have been recognized.
Pholis gunnellus (gunnel): known from the Greenland coast between
Julianehaab and Ho l steinsborg.
Pholis fasciatus (rock eel): an inhabitant of the shore salt water
along the Greenland coast north to 73° N. latitude; also reported from Devon
Island and Hudson Bay.
Stichaeus punctatus (spotted snake blenny): common in the shore zone of
West Greenland to 73° N. latitude; also reported from Hudson Bay.
Eumesogrammus praecisus : distribution the same as the spotted snake
blenny in Greenlandic waters; also reported from Port Burwell, Ungava Bay.
Lumpenus maculatus (shanny): common along the west coast of Greenland
from Ivigtut to Jacobshavn; also reported from Port Burwell.
Lumpenus lampetraeformis (snake blenny): common from Godthaab to Jacobs–
havn, Greenland.
Lumpenus medius : rare from Disko Bay north to Northeast Bay, Greenland.

EA-Zoo. Hildebrand: Marine Fishes of American Arctic

Lumpenus fabricii : a very common blenny along the west coast of Green–
land from Nanortalik to Godhavn. Elsewhere it has been recorded from Devon
Island, Ungava Bay, and Hudson Bay.
Anarhichas lupus (wolf fish): fairly common from West Greenland to
Umanak Fjord in the north.
Anarhichas minor : known from Davis Strait on both sides of the sub–
marine ridge.
Anarhichas denticulatus : common in Davis Strait south of the submarine
ridge.
Lycodes vahlii ( l e elpout): common in the deep water of Davis Strait.
Lycodes reticulatus (arctic eelpout): a common eelpout in Davis Strait
north to Umanak, Greenland; elsewhere reported from Ungava and Hudson Bay.
Lycodes esmarkii : known from the deep water of Davis Strait.
Lycodes eudipleurosticus : a common eelpout in the deep cold water of
Baffin Bay and northwest Greenland.
Lycodes seminudus : known from Jacobshavn to Upernivik, Greenland.
Lycodalepis polaris : A widespread range in Arctic America is indicated
by scattered records from Whale Sou n d, Devon Island, Cumberland Sound, Hudson
Bay, Point Barrow, and Bering Strait.
Lycenchelys ingolfianus : known only from the deep water of Davis Strait.
Gymnelis viridis (fish doctor): a common eelpout throughout the Arctic;
it has been reported from most stations where collecting has been done.
Bythites fuscus : Only a single specimen of this fish exists; it was
collected at Fiskenaes, Greenland.
Ceratias ho l bölli : uncommon in the deep water of Davis Strait.

EA-Zoo. Hildebrand: Marine Fishes of American Arctic

Oneirodes eschrichtii : rare in the deep water of Davis Strait.
Himantolophus groenlandicus : very rare in the deep water off Greenland.
Summary
The Arctic is noted for a paucity of fish fauna. The well-known and
rich fauna of West Greenland, warmed by Atlantic water, is strongly in con–
trast to the high-arctic waters of northern Ellesmere Island, where to date
only two species of fish have been discovered, Salvelinus alpinus and Oncocottus
quadricornis .
If the areas whose faunas are influenced by the warming effects of Atlan–
tic or Pacific water are excluded, the fauna is characterized by relatively
few families of fish. The common anadromous form which enters most of the
rivers and streams is the arctic char, a member of the salmon family. Small
brackish streams are characterized by sticklebacks. Sculpins are represented
by a variety of species from the shore zone to deep water. Other common mem–
bers of the shallow and deep zones are the peculiar lumpfish and liparids, or
sea snails. The eel-like blennies and eelpouts are common in the Laminaria
zone and deep water. The arctic pollack, a member of the cod family, is the
most common pelagic form, and is often sighted near the surface among the ice
floes or in open leads.

EA-Zoo. Hildebrand: Marine Fishes of American Arctic

BIBLIOGRAPHY

1. Bean, T.H. “Fishes collected in Cumberland Gulf and Disko Bay,” U.S.Nat.
Mus. Bull . no.15, pp.107-38, 1879.

2. Dresel, H.G. “Notes on some Greenland fishes,” U.S.Nat.Mus. Proc . vol.7,
pp.244-58, 1894.

3. Dunbar, M. J. “Marine young fish from the Canadian eastern Arctic,” Canada.
Fisheries Re d s . Bd. Bull . no.73, 1947.

4. Dymond, J.R. “The Coregonine Fishes of Hudson and James Bay,” Contr.
Canad. Biol. of Fish , n.s., vol.8, no.1, 1933.

5. - - - -. “The Coregonine fishes of northwestern Canada,” Toronto. Roy.
Ont.Mus. Zool. Contr . no.24, 1943.

6. - - - -. “Notes on the distribution of Salmo salar and Salvelinus alpinus
in northeastern Canada,” Canad. Field Nat . vol.46, p.185, 1932.

7. - - - -. “Pacific salmon in the Arctic Ocean.” Pacific Sci. Congr. 6th,
1939. Proc . vol.3, p.345.

8. Ehrenbaum, E. “Die Fische,” Fauna Arct ., Jena, vol.2, pp.65-168, 1902.

9. - - - -. Nordisches Plankton, 1905, Zool. Teil l 413 pp.

10. Fabricius, Otto. “Pisces,” his Fauna Groenlandica . Hafniae et Lipsiae,
Rothe, 1780, pp.137- 84 83.

11. Fowler, H.W. “Fishes collected by the Peary Relief Expedition of 1899,”
Acad. Nat. Sci. Philad. Proc . [: ] vol.66, pp.359-66,
1914.

12. - - - -. “Notes on some arctic fishes with a description of a new Onco–
cottus,” Acad. Nat. Sci. Philad. Proc . vol.57, pp.362-70, 1905-06.

13. Gunther, Albert. “Account of the fishes collected by Capt. Fielden between
78 to 83° N. lat. During the arctic expedition of 1875-76,”
Zool. Soc. Lond. Proc . p.293, 1877.

14. - - - -. “Report of a collection of fishes made by C. Hart during the late
arctic expedition,” Zool. Soc. Lond., Proc . 1877, p. 475.

15. Halkett, Andrew. Check List of the Fishes of the Dominion of Canada and
Newfoundland . Ottawa, Printer to the King, 1913.

16. Hildebrand, H.H. Marine Fishes of Arctic Canada . Thesis, McGill University,
[: ] 1948.

EA-Zoo. Hildebrand: Marine Fishes of American Arctic

17. Hildebrand, S.F. “Annotated list of fishes collected on the several
expeditions to Greenland, Fox Basin region, and the coast
of Labrador by Capt. R. A. Bartlett,” Medd. Grønland , vol.125,
no.1, 1939.

18. Je n sen, Ad.S. Concering a change of climate during recent decades in
arctic and subarctic regions from Greenland on the west to
Eurasia on the east,” Danske Vidensk. Selsk. Biologiske Medd .
vol.14, no.8, 1939.

19. - - - -. “Contributions to the Ichthyofauna of Greenland 1-3. Spolia
Zoologica Musei Hauniensis II” Skr Skr . Uni. Zool. Mus. Kbhvn. 1942.

20. - - - -. “Contributions to the Ichthyofauna of Greenland 4-7. Spolia
Zoologica Musei Hauniensis IV . Skr Skr . Uni. Zool. Mus. Kbhvn, 1944.

21. - - - -. “Fishes,” Norwegian Arctic Expedition in the “ Fram ,” 2nd,
1898-1902. Report . vol.3, no.25, 1910.

22. - - - -. The Greenland Halibut ( Reinhardtius hippoglossoides ). København,
Levin 2 Munkgsgaard, 1935.

23. - - - -. “Investigations of the ‘ Dana ’ in west Greenland waters in 1925,”
Conseil Perm. Internat. Explor. Mer. Rapport , vol.39, pp.85-91,
1926.

24. - - - -. “On subspecies and races of the lesser sand eel ( Ammodytes lancea ),”
Danske Vidensk. Selsk. Biologske Medd . vol.16, no.9, 1941

25. - - - -. “Researches on the distrib. boil. and syst. of Greenland fishes
( Sebastes marinus ),” Dansk Naturhist Foren. Copenhagen, Vidensk .
Medd . vol.74, pp.89-109, 1922.

26. - - - -. The Selachians of Greenland . København, Bianco Lunos Bogtrykkeri,
1914.

27. Jordan, D.S. & Evermann, B.W. “The fishes of North & Middle America,”
U.S. Nat.Mus. Bull . Parts I to IV. Washington, 1896-1900.

28. Jordan, Evermann, & Clark. “Check List of the fish and fishlike vertebrates
of North and Middle America,” Rept. of Comm. of Fisheries 1928
(1930) Part 2.

29. Kendall, W.C. “The Fishes of Labrador,” Portland Soc. Nat. Hist. Proc .
1909, vol.2, pt.8, pp.207-44.

30. Lütken, C.F. “The crustacean of Greenland,” Jones, T.R. Manual of the
Natural History, Geology, and Physics of Greenland . . .
together with Instructions . . . for the Use of the Expedition .
Lond., Her Majesty’s Stationery Office, 1875.

EA-Zoo. Hildebrand: Marine Fishes of American Arctic

31. Murdock, John. “Fishes,” International Polar Expedition to Point Barrow,
Alaska, 1881-1883. Report . Wash., G.P.O., 1885, pp.129-32.
U.S. Cong.House, 48th Cong.2d S. Ex.Doc . no.44.

32. Pfaff, J.R. “Fishes,” Fifth Thule Expedition, 5th, 1921-24. Report ,
vol.2, no.7, pp.1-19, 1937.

33. Reinhardt, J.C.H. Ichthyologiske Bidrag til den Grönlandske Fauna .
Kbhvn, 1837.

34. Reinhardt, J.T. Naturhistoriske Bidrag til en Beskrivalse of Grønland .
Kjøbenhavn, Klein, 1857, pp.20-27.

35. Richardson, John. “The Fishes,” his Fauna Boreali-Americana . London,
1836, Pt.3.

36. - - - -. “Notices of the fishes,” Franklin, John. Narrative of a Journey
to the Shores of the Polar Sea in the years 1819, 20, 21, and 22.
Lond., Murray, 1823, Appendix 6, pp.705-28.

37. Scofield, N.B. “List of fishes obtained in the waters of arctic Alaska,”
Jordan, D.S. The Fur Seals and Fur-Seal Islands of the North
Pacific Ocean , Wash., G.P.O., 1899, pt.3, pp.493-509.

38. Turner, L.M. Manuscript on Fishes of Labrador Peninsula, U.S.Nat. Mus. 1886.

39. Vladykov, V.D. “Fishes from the Hudson Bay region,” Contr. Canad. Biol .
Fish . n.s., vol.8, 1933.

Henry Hildebrand

Arctic Marine Fishes

EA-Zoology
(Orvar Nybelin)

ARCTIC MARINE FISHES

CONTENTS
Page
Introduction 1
Ecology 5
Pelagic Fish 5
Bottom Fish 9
Occurrence and Distribution of Bottom Fish 10
Ecological Factors 10
Arctic Boreal Species 13
Arctic-Subarctic Species 14
Subarctic Species 14
Panarctic-Subarctic Species 15
Low-arctic Species 16
Pan-arctic Species 17
High-arctic Species 17
Wandering Fish and Brackish-water Fish 19
Zoogeography 20
Circumpolar Species 20
Continuous Circumpolar Species 20
Discontinuous Circumpolar Species 21
Influence of Climatic Changes on Distribution 25
Bibliography 27

EA-Zoology
(Orvar Nybelin)

ARCTIC MARINE FISHES
[ Editor’s Note : In this article Dr. Nybelin uses
an ecological classification which divides the arctic
zone into “high arctic” and “low arctic.” His “subarctic”
thus becomes a narrow transition zone. The reader should
not that, in most of the other articles in this volume,
the term “subarctic” includes two of Dr. Nybelin’s zones:
‘low arctic” and “subarctic.”]
Introduction
Although the number of species of fish in the Arctic Sea must be
regarded as being considerably less than in most other sea areas of corres–
ponding size, it is difficult to give a short survey of its fish fauna.
There are several reasons for this difficulty.
Considering the Arctic Sea as a whole, we still know very little about
some of its essential sections even though others are well investigated,
i.e., the Greenlandic waters mainly by Danish, the Spitsbergen area by
Swedish, and the Alaskan area by American investigators. Thus the fauna of
the central arctic deep basin, as well as large sections of the North
American arctic coastal areas, are almost entirely uninvestigated, due
mainly to the technical difficulties involved in surmounting their natural
barriers. While the Russians, in the last decades, have carried out
extensive investigations along the north Russian and north Siberian coastal
areas, their publications are, to a large extent, rather inaccessible.
Furthermore, in several cases, recent and thorough investigations have

EA-Zoo. Nybelin: Marine Fishes

led to a new species concept. Thus many of the earlier published works
cannot be taken into consideration, from an ecological and zoogeographical
viewpoint, until the original material is reexamined in the light of this
new concept. An additional difficulty arises from the face that those
investigators who have worked, more or less thoroughly, with the n N orth
Pacific arctic fish fauna apparently have not had access to necessary com–
parative material from the Atlantic arctic area, and vice versa. Whether
these areas are stocked with identical or only with very closely related
species or subspecies is a matter of great uncertainty. Consequently, in
the present article, which has been based almost entirely on a study of the
literature, it has not been possible to give a complete list nor a compre–
hensive ecological and zoogeographical analysis of all arctic fish species.
Therefore the following lines do not claim to be anything other than an
attempt to give a general survey of the marine arctic fish fauna from an
ecological and zoogeographical viewpoint. Consequently the mentioning of
species throughout the te s x t is intended only to exemplify the account, and
should not be considered as a complete list of arctic fish species. For
reasons mentioned above, the comparatively well-known Atlantic arctic area,
with its greater variation of ecological conditions, has been treated in
greater detail than the Pacific arctic area.
The Arctic or North Polar Sea, viewed geographically, is only an Atlantic
inland sea with a broad and comparatively deep connection to the North Atlantic.
Besides, there is a comparatively narrow and shallow (hardly 50 meters)
connection with the Pacific Ocean through Bering Strait. This shallow strait
is bounded on the north and south by considerable sea areas with maximum
depths of only about 100 meters. The Bering Sea, for the most part arctic,

EA-Zoo. Nybelin: Marine Fishes

has a rather definite southern boundary at the North Pacific, but the broad
North Atlantic offers an indefinite southern boundary due to warm Gulf Stream
currents which displace the cold water masses considerably northward. More–
over, these two Arctic Sea outlets are also different from a hydrographic
standpoint.
The character of a marine fauna is dependent, as Ekman (2) points out, upon the
hydrographic conditions, and not upon its geographical position. Consequently,
according to Ekman, we cannot accept the entire north Polar Sea as purely
high-arctic, i.e., having waters, as a rule, with temperatures below zero
(°C.). Only the following arctic coastal areas can be considered purely
high-arctic: north and east Spitsbergen, the northernmost part of Barents Sea,
Kara Sea, the north coast of Siberia, the North American Arctic Sea coasts
except a little area at Bering Strait, northwest and northeast Greenland
about to 69° N. latitude, and Jan Mayen. On the other hand, the following
areas have somewhat higher temperatures and are usually designated as low-
arctic: south and southeast Greenland, west and south Spitsbergen, the central
portions of Barents Sea, and the White Sea’s inner and deeper areas. Of
course, designating these areas as low-arctic does not preclude the possibility
that high-arctic conditions can exist locally, as, for example, the inner
portions of the West Spitsbergen fjords. Finally, the coasts of Labrador and
south to Cape Cod, southwestern Greenland, north and east Iceland, east Fin–
marken, the Murman C c oast, and the White Sea’s shallower parts, are usually
regarded as subarctic transitional area. However, this applies only to the
uppermost strata or the littoral zone.
The North Atlantic deep areas are demarcated very sharply toward the
north by two shallow ridges. One, nowhere deeper than 560 meters, extends

EA-Zoo. Nybelin: Marine Fishes

from East Greenland-Iceland-Faeroe Islands-Shetland-Scotland; another
extends between West Greenland and Baffin Island with a maximum depth of
approximately 700 meters. Few areas, if any, exhibit such sharp tempera–
ture differences as exist on either side of the ridge between the Faeroe
Islands and Shetland, to so-called Wyville-Thomson ridge. North of this
ridge, from about the 600-meter depth and downward, the water temperature
is constantly below zero °C. — typically high-arctic. Contrastingly, the
deep waters w s outh of the Wyville-Thomson ridge have a temperature of about
+3°C. — characteristic of the A r tlantic Ocean. Cold water masses (below
0°C.), coming from the north, stream over the ridge giving its summit and
uppermost southern slope a low-arctic to subarctic character. Consequently,
deep waters between Greenland and Scandinavia may show arctic conditions
nearly as far south of the Arctic Circle (depending on the North Atlantic
ridge), as the upper strata may show boreal conditions to the north of the
Arctic Circle (depending on the Gulf Stream).
The sound between northeast Greenland and Spitsbergen divides the
deep - sea areas north of the North Atlantic cross ridge into two deep-sea
basins — the Norwegian Sea basin (depth more than 3,600 meters) and the
North Polar basin. However, the threshold depth of this sound is considerable,
about 1,500 meters. For this reason, the hydrographical conditions in the
deeper parts of these two basins (600 meters and deeper) ø are similar,
both being characterized by a temperature never higher than −1°C. and a
constant salinity of 34.93°/oo. The Norwegian Sea basin and the North
Polar basin, together with the completely isolated Baffin Bay depth, are
designated by Ekman as the Arctic Deep Sea. These three areas (the Arctic
Deep Sea) will be dealt h with in their entirety in the following report.

EA-Zoo. Nybelin: Marine Fishes

In spite of the unmistakably arctic character of Bering Sea and the Sea
of Ok n h otsk, they will be considered only when their conditions give reason
to draw a direct comparison with the rest of the arctic areas.
ECOLOGY
Marine fish are usually divided into two main categories based on their
life habits — pelagic fish and bottom fish. Although there are no clear-cut
boundaries separating these categories, it is a good general division of
marine fish and can also be used for arctic and subarctic fish.
Pelagic Fish
There are fish that live their entire life in the free-water strata,
independent of the sea bottom. Thus they may be thought of as being ecologi–
cally equivalent to the plankton forms among the invertebrates. Their roving
life in the free-water strata allows a wide distribution, which is limited
only by unfavorable hydrographical conditions. Moreover, it is relatively
easy for pelagic fish to be carried far beyond their usually area of distribu–
tion by currents or other chance circumstances.
As far as we know today, the arctic waters are very sparsely occupied
by pelagic fish. Most (perhaps all) are widely distributed species, which
were accidentally carried up into the arctic waters by the Gulf Stream.
Apparently they have not established a breeding population in the arctic
waters. Based on our present knowledge, the strictly arctic fish fauna lacks
true pelagic representatives. This is an exceedingly remarkable condition,
considering the great wealth of arctic plankton. The arctic fish mainly
make use of this rich source of food indirectly by feeding upon bottom
invertebrates, which use the dead plankton organisms as food.

EA-Zoo. Nybelin: Marine Fishes

Pelagic fish in subarctic or low-arctic waters are found in those
areas where Gulf Stream currents regularly penetrate. This is especially
so in Davis Strait and off the coast of West Greenland, but pelagic fish
have also occasionally been taken at east Finmark, at the Murman C c oast,
and at West Spitsbergen. Small species which may normally be caught with
ordinary pelagic equipment are: Microstomidae: Nansenia groenlandica ,
first described from one specimen taken in Greenlandic waters but later
found to be common in the North Atlantic between 63° and about 49° N.
latitude; Bathylagus benedicti , known both from the north and south
Atlantic and taken at least 11 times in the southern part of Davis Strait.
[: ] Gonostomatidae: Cyclothone microdon and C. p b raueri , cosmo–
politan species which have been found in [: ] Davis Strait.on 17 and
8 occasions respectively. Stomiatidae: Stomias boa ferox , reported 13
times from West Greenland and Davis Strait. The most frequently caught
pelagic species are the North Atlantic Myctophiids Myctophum glaciale
and M. arcticum . The former ( glaciale has been taken 43 times along the
coast of northwestern Greenland, once off the southernmost part of East
Greenland. [: ] and it has also been taken
in Baffin Bay, at Port Burwell ( u U ngava), and at least twice at Spitsbergen.
The latter ( arcticum ) has been collected 22 times outside the West Greenland
coast. There are 5 records of the more cosmopolitan Lampanyctus crocodilus
from Davis Strait and it is also mentioned as having been found at Port
Burwell. On three occasions Lampanyctus elongatus has been collected
at West Greenland.
The records of the larger , and no doubt fast-swimming Paralepis Paralepis species
are different in that the young have been regularly taken in large numbers

EA-Zoo. Nybelin: Marine Fish

in the southern areas of the North Atlantic, while the adults have been
almost exclusively found farther to the north at the Arctic Sea’s boundary.
Thus P. coregonoides borealis has often been taken at West Greenland but
only once from Norway, once from England, and once from the United States;
P. rissoi krøyeri has been found 6 times at West Greenland, once at East
Greenland, 5 times at south Iceland, twice at Norway, once at the Murman
C c oast, 6 times at North America, and once at Port Burwell (Ungava);
P. brevis has been taken twice at Iceland, once at East Greenland, and once
in the Skagerrak.
Most, perhaps all, of these specimens seem to have been paralyzed by
the cold water, for they were found disabled or dead on the surface, and
also in the stomachs of seals or fish. Therefore it can be definitely stated
that these fish have gone beyond their usual area of distribution. The
fact that young of these species have been taken only to the south is a
good illustration of the ineffectiveness of the prevailing pelagic trapping
methods for the larger and faster fish species.
The following species may also belong to this category: Anotopterus
arcticus
- probably pelagic, known only as a skull taken from the stomach
of a halibut in Davis Strait; Saccopharynx ampullaceus - this n N orth Atlantic
fish was once found dead floating in Davis Strait; Plagyodus ferox - 4 specimens
of this nearly cosmopolitan fish were found dead (floating or washed up on
shore) on the coast of West Greenland. The two latter species have, however,
been trapped elsewhere several times. Ceratias holboelli , Oneirodes eschrichti ,
Himantolophus groenlandicus , and Caristius groenlandicus (probably pelagic ,
known from only one specimen) are peculiar deep-sea anglers, which have been
taken only with trapping gear. The North Atlantic Trachypterus arcticus has

EA-Zoo. Nybelin: Marine Fish

occasionally been found off northernmost Norway, and the cosmopolitan
Lampris pelagicus was once found as far north as the M urman C c oast. Finally
it should be mentioned that the North Atlantic herring Clupea harengus,
which [: ] previously was only accidentally caught as isolated specimens at
Greenland, has in later years been taken at Jan Mayen, Spitsbergen, Novaya
Zemlya, and in the Kara Sea. This range extension may be due to the recent
n N orth Atlantic “climatic improvement.”
I believe it is clear that all of the above-mentioned pelagic fish
are only accidental visitors to the polar area. Are there no purely arctic
pelagic fish species? The polar cod Boreogadus saida has often been considered
an arctic pelagic fish. It occurs over almost the entire arctic area, from
the littoral zone near shore out to about 350 meters depth, and it has even
been found near the surface between drifting ice floes. Concerning the
occurrence near ice floes, Jensen (6, p.132) writes: “White Bay and Lönnberg
conclude from these observations that Gadus saida may be pelagic, S o ø ren Jensen
in his diary puts forth the view that the polar cod out in the big ice should
not be regarded as pelagic, no more than the amphipods and masses of diatoms
found together with them on the ice foot; he is of the opinion that they are
coastal forms which with the drift ice have been carried from the shore out in the
open sea and outhere, in a peculiar way, continue their “ littoral mode of Single quote
life associated with the ice floes.” Thus the polar cod is not actually
a pelagic species.
In The Depths of the Ocean , by John Murray and Johan Hjort, Hjort states
that Paraliparis bathybii should be considered a bathpelagic species. He
bases this statement on the evidence that this species, which has often
been caught by trawling nets, was also taken once in a pelagic net which

EA-Zoo. Nybelin: Marine Fish

was towed at a great depth. It is possible that bathybii may have been
taken from the free-water strata as the trawls were hauled up to the surface,
but we must wait for additional evidence, in particular from pelagic hauls,
before stating definitely that P. bathybii is a bathpelagic species.
It conclusion, we know of no truly arctic pelagic fish. All of the
pelagic fish taken in the arctic region must be regarded as accidental
visitors which have been carried far beyond their normal distribution by
Gulf Stream currents from the North Atlantic. To the best of our knowledge,
there no similar accidental invasion from the North Pacific to the arctic
area.
Bottom Fish
The arctic fish fauna is made up mainly of bottom fish or species which,
because of food and other conditions, are more or less strongly bound to, or
dependent on, the sea bottom, from the shore zone down to the greatest depths.
The fact that fish are dependent upon the sea bottom does not preclude the
possibility that they may occasionally leave the bottom-water strata. For
example, species of the genus Trigla and the flat fishes are strongly adapted
to bottom life, but they may occasionally be taken in upper water la [: ] y ers.
However, this cannot alter our opinion that they are true bottom fish.
There are some bottom fish that might be thought of as being arctic
species from a geographical standpoint, but when considered ecologically
we find that they are not actually arctic. To this group belong the following:
Centroscyllum fabricii , Alepocephalus agassizii , Notacanthus chemitzii ,
N. rostratus , Synaphobranchus kaupii Histiobranchus in v f ernails , Nematonurus
armatus , “Mecrourus aequalis , Chalinura brevibarbis (= C. simula acc. to
Lütken), Trachyrhynchus murrayi , Antimora rostrata , Haleprophyrus eques ,)

EA-Zoo. Nybelin: Marine Fish

Cottunculus torvus , Lycenchelys ingolfianus , and Lycodonus ophidium . These
are all Atlantic, in most cases North Atlantic species, which are found as far
north as the North Atlantic cross ridge but only rarely have been found north
of this ridge. No doubt Bythites fascus also belongs to the preceding group.
This fish has been found only once (1834) off West Greenland. The other
known species of this genus lives in the deep waters of East India, and in
general the whole family in characteristic of deep water.
Occurrence and Distribution of Bottom Fish
Before discussing the occurrence and distribution of arctic bottom fish
it is necessary to consider some ecological principles.
Ecological Factors . Certainly temperature is the most important
ecological factor. Above all it is the key factor in our definition of the
arctic region (see above). Of course the temperature sensibility and the
temperature span may vary from different species of fishes as well as for
other animals. Some can endure temperature changes only within a very
narrow range (stenothermic species) and among them some species may be
adapted to a very narrow range of negative temperatures, others to a narrow
range of low positive temperatures and so on. On the other hand, there are
species which are adapted to a much broader temperature range (eurythermic
species). As a rule, eurythermic fish consequently have a wider distribu–
tion than stenothermic fish which are limited by their considerably narrower
temperature boundaries.
Moreover, different species react differently to change in the Water’s
salinity. In reacting to salinity, specie may be designated as stenohaline
if they are limited by a narrow saline range, and euryhaline if they show a

EA-Zoo. Nybelin: Marine Fish

tolerance to a wider range of saline variations.
Depth is another important ecological factor, and the response of fish
to it varies considerably. Some species are bound to certain fixed depths
(stenobathic species). However, one can distinguish between stenobathic
shallow-water species, stenobathic species in intermediate depths , and steno–
bathic deep-water species. Other species are not so narrowly restricted by
depth conditions and may exist within more or less unlimited depth boundaries
(eurybathic species).
It is upon the combination of the rather closely related factors of
temperature and depth that we base our ecological classification of the
arctic marine fish fauna. Naturally, other factors such as salinity, nature
of the bottom, food supply, etc., also play an important role.
The Swede N. v. Hofsten, in his well-known work Die Fische des Eisfjords
(3), was the first to give an analysis of the arctic marine fish fauna.
Continuing from his earlier analyses of the arctic echinoderms and decapod
crustacea, v.Hofsten divided the arctic fish into the following main groups:
( 1 ) arctic species, ( 2 ) arctic-boreal species, ( 3 ) boreal-arctic species,
and ( 4 ) boreal species reaching the low-arctic zone. The first group (arctic
species) is further subdivided into high-arctic and low-arctic species. High–
arctic species are characteristically bound to areas with negative temperatures,
while low-arctic species are found in areas with low positive temperatures.
In both these cases the species are strictly cold-stenothermic species. However,
those species which occur in both the high- and low-arctic temperature areas
are designated as panarctic. The second group (arctic - boreal species) is
broken down into panarctic-north boreal species, mainly arctic species,
panarctic-panboreal species, and low - arctic-boreal species.

EA-Zoo. Nybelin: Marine Fish

This is a well-founded, and surely in essentials a permanent, division of
arctic fish. Yet it should be pointed out that it is difficult to draw up
boundaries between different ecological categories , v.Hofsten (3 ) , p.13 p. 103) himself
remarks that such a division has primarily a formal value, and that those
who expect to find a strict conformance in nature have confused aims and
means. This is especially no when one deals with such mobile forms as fish.
They can often react to temporary or seasonal changes in the environment, and
can easily stray beyond their normal or typical environment. Thus, isolated
discoveries may easily distort the picture of the species’ normal environmental
requirements. This may be an important factor in the ecological consideration
of those rare species which have been taken only a few times. It is clear
that more discoveries and increased knowledge of arctic fish must, in many
cases, lead to a revised concept of the species and its ecological niche.
Furthermore, our conception of several species has recently undergone
a considerable change from a taxonomic-systematic respect. For example,
v.Hofsten regards Triglop pingelii as panarctic-north-boreal. According to
A. S. Jensen’s thorough analysis ( Jensen 1944 5 ), this specias is broken up
into four subspecies: the high-arctic Triglops p. pingelii , the low-arctic
T. p. pietschmanni , the subarctic T. p. islandicus , and the north-boreal
T. p. murrayi . Naturally, these must be assigned to their different ecological
categories. The arrangement that follows must consequently not be thought of
as a criticism of v. Hofsten’s classification, but rather as a modernization
based on more recent data. For example, I agree with Ekman (2) that the
arctic-boreal transition region ought to be regarded as a special subarctic
area because, as we shall see later, it has a characteristic fauna of its own.
Before going further into this discussion it might be well to consider

EA-Zoo. Nybelin: Marine Fish

those boreal species which penetrate into the subarctic , and low-arctic
zones , respectively. A considerable part of the North Atlantic’s economically
most valuable fish are found in these zones, for example: Gadus callarias ,
G. aeglefinus , Pollachius virens , Molva molva , Brosmius brosme , Hippoglo s sus
hippoglossues , Glyptocephalus cynoglossus , Sebastes marinus , Cyclopterus lumpus ,
and Anar c rhichas lupus . Formerly these species were found only occasionally
in the geographic arctic region, perhaps as temporary guests, but due to the
“climatic improvement” of recent years, they are now frequently found farther
north. It is interesting that a considerable amount of fishery operations
are now being conducted in the arctic area for some of these species. Probably
the following species should also be included in this group: Squalus acanthias ,
Raja fyllae , R. lintea , Coryphaenoides rupestris , Molva dypter y gia (?),
Ammodytes lancea marinus , the cyclostome Myxine glutinosa , and possibly Raja
radiata if it is not rather a low-arctic-boreal species.
Arctic-Boreal Species . The fish species of this group are quite
markedly eurythermic, and therefore find favorable ecological conditions in
both the boreal and arctic zones. The various species are, however, apparently
adapted to somewhat different temperature ranges. At least one of them,
Hippoglossoides platessoides , seems to be adapted to somewhat higher tempera–
tures for it occurs within the whole boreal area, whereas its arctic distribu–
tion is limited to the subarctic and low-arctic regions. v.Hofsten has
characterized platessoides as low-arctic-boreal. Thus it stands close to
the preceding group, especially Raja radiata , but it is of more general occur–
rence in the low-arctic area than is radiata . A few other species are even
more eurythermic, as they occur not only within the boreal area but also in
true arctic waters. These panarctic-panboreal species are the common bullhead,

EA-Zoo. Nybelin: Marine Fish

Cottus scorpius , and the nominate form of Liparis liparis . Finally, the
panarctic-north-boreal species seems to be adjusted to somewhat lower
temperatures, and consequently avoid the more southern and warmer parts
of the boreal area. Lumpenus lampetriformis stands nearest to the preceding
species, having its southernmost distribution in the North Sea. It is also
quite [: ] plentiful in the Baltic. Artediellus uncinatus europaeus , Lumpenus
maculatus , and Careproctus reinhardti are not found farther to the south than
in the Skagerrak. The ice shark, or Greenland shark, Somniosus microcephalus ,
which has great economic importance in Greenland also avoids the warmer boreal
waters. The boreal distribution of Cottunculus microps extends only as far
south as Trondheim Fjord.
Arctic-Subarctic Species . As pointed out in the introduction, the marine
arctic area can be divided into a high-arctic and low-arctic subarea based
on temperature differences. To these areas may be added the subarctic area,
designated by v. Hofsten as the boreal-arctic transition area. This latter
has a comparatively small extension. (See note at beginning of this article
concerning the use of the term “Subarctic.”) This and its transitionary
character appear to make the subarctic area unsuitable for the development
of a fish fauna of its own. Consequently, the species occurring here belong
partly to the warmer arctic-boreal group, and partly to the colder panarctic–
subarctic group. However, it appears that quite a few species are almost
entirely limited to the subarctic area.
Subarctic Species . The range of the obviously subarctic Raja spinicauda
includes: West Greenlandic waters, Iceland’s southeast coast, near Bear Island,
the Barents Sea north of the Murman C c oast, and at the Skolpenbank (depths
between 175 and 836 meters, and between the temperatures of +0°.05 to 3°.8C. +0.05° to 3.8°C. ).

EA-Zoo. Nybelin: Marine Fish

The following also belong to this group: Macrourus berglax , Reinhardtius
hippoglossoides , Anarrhichas minor , A. denticulatus , and Lycodes esmarkii .
These species occur from east Finmarken west to Storeggen at the Norwegian
west coast , at Iceland’s north and east coast, off the eastern United States
coast south to Cape Cod, and all except esmarkii are found off Bear Island
and West Greenland. Both of the Anarrhichas species and L. esmarkii are
also found on the Faeroe plateau and the Faeroe-Iceland ridge. A. minor
also occurs at West Spitsbergen, in the White Sea, and at the Murman
C c oast where denticulatus has also been found. The presence of R. hippoglos–
soides
at southeast Greenland suggests that this species might more
accurately be designated low-arctic-subarctic. It is possible that both
the Anarr c hichas species and M. berglax may also be low-arctic-subarctic.
However, Triglops pingelii islandicus and Lycodes vahlii lugubris , which are
characteristic of Iceland’s subarctic coasts, and Aspidiophorides monopterygius ,
known only from West Greenland, Davis Strait, and the United States east
coast to Cape Cod, must be regarded as pure subarctic species.
Panarctic-Subarctic Species . The upper temperature limits of these
eurythermic species almost coincide with subarctic conditions, but they are
also quite cold tolerant as they can withstand high-arctic temperatures.
C G aidropsarus argentatus has been found throughout most of the subarctic area,
and also at East Greenland and Jan Mayen. Leptagonus decagonus , also subarctic,
has been taken at Jan Mayen, and at north and east Spitsbergen. We can also
include in this group Aspidophoroides olrikii from the subarctic and Kara Sea,
and Liparis liparis bathyarctious from Spitsbergen, Barents Sea, Jan Mayen,
and northern Norway. Gymnelis viridis , which occurs within the whole arctic
area, has once been taken at Iceland’s northern coast and also outside

EA-Zoo. Nybelin: Marine Fish

Labrador and there is, perhaps, equal justification for including it in
this group as in the panarctic group where it has formerly been placed.
This is also the case with the polar cod, Boreogadus saida , which on several
occasions has been taken from the waters around Iceland, and once off
Labrador. Gymnocanthus tricuspis is known from both the high- and low–
arctic regions, and also from the Murman C c oast, north Norway, and Labrador.
Possibly Icelus bicornis bicornis should also be placed in this group.
Although the following species are partly subarctic, their occurrence
in Bering Sea and the Sea of Okhotsk is sufficient evidence to permit their
inclusion here. These species, with their distribution, are: Stichaeus
punctatus
, - west Greenlandic waters, Hudson Bay south to Newfoundland,
Bering Sea, Sea of Okhotsk, and the Japanese Sea; Eumesogrammus praecisus,
West Greenland waters, Hudson Bay and Strait, Bering Sound and Sea, and
the See of Okhotsk; Lumpenus fabricii , west Greenlandic waters, Gulf of
St. Lawrence, Wellington Channel, off the Murman C c oast, White Sea, Novaya
Zemlya, and Bering Sea; and Eumicrotremus spinosus , panarctic and the
eastern United States coast down to Main e .
Low- a A rctic Species. This group of species is neither numerous nor
sharply characterized. The capelin, Mallotus villosus , is usually thought
of as being a representative low-arctic species (2); but its interesting
spawning wanderings make it difficult to assign