Part II: Marine and Freshwater Zoology Encyclopedia Arctica 3: Zoology (Excluding Birds)

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Part II: Marine and Freshwater Zoology

Encyclopedia Arctica 3: Zoology (Excluding Birds)

Part II: Marine and Freshwater Zoology

Marine

Faunistic Effects of Climatic Change in the North

Unpaginated | Vol_III-0468
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

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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

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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

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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,

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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

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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

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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

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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

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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

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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

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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

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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 ),

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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

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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

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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).

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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

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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

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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.

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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.

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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)

Unpaginated | Vol_III-0488
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

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(Max J. Dunbar)

FAUNISTIC EFFECTS OF CLIMATIC CHANGE IN THE NORTH

Introduction

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

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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

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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.”

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,

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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

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to an increased influence of Atlantic water, as in West Greenland.

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

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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

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

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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.

Northward creep of vegetation has been observed in Iceland and in

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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.

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

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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.

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

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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

Following immediately upon the hydrographic changes described above,

brought about mainly by an increase in the heat and transport of the Gulf

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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.

“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 ),

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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.”

Perhaps the most spectacular of all these faunal changes has taken place

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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

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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).

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.

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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

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that it is a fairly recent arrival in Hudson Strait. It has since been taken

in numbers in Ungava Bay (unpublished date).

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

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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.

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