The effective fishing area may be assumed to lie within a radius of a hundred miles from each shore station and floating factory anchorage, and a rough estimate of all the Falkland stations works out at 160,000 square miles. The total for the whole Falkland area is about 2,000,000 square miles, which is roughly less than a sixth of the total Antarctic sea area. The question then arises as to how far the “catch percentage” during the short fishing season affects the total stock, but so far one can only conjecture as to the actual results from a comparison of the numbers seen, chiefly by scientific and other Expeditions, in areas outside the intensive fishing area with the numbers and percentage of each species captured in the intensive fishing area. Sufficient evidence, however, seems to point quite definitely to one species—the humpback—being in danger of extermination, but the blue and fin whales—the other two species of rorquals which form the bulk of the captures—appear to be as frequent now as they have ever been.
The whales captured at the various whaling stations of the Falkland area are confined largely to three species—blue whale
(Balænoptera musculus)
, fin whale
(Balænoptera physalus)
, and humpback
(Megaptera nodosa)
; sperm whales
(Physeter catodon)
and right whales
(Balæna glacialis)
being only occasional and rare captures, while the sei whale
(Balænoptera borealis)
appeared in the captures at South Georgia in 1913, and now forms a large percentage of the captures at the Falkland Islands. During the earlier years of whaling at South Georgia, and up to the fishing season 1910-11, humpbacks formed practically the total catch. In 1912-13 the following were the percentages for the three rorquals in the captures at South Georgia and South Shetlands:
Humpback 38 percent, fin whale 36 percent, blue whale 20 percent. Of late years the percentages have altered considerably, blue whales and fin whales predominating, humpbacks decreasing rapidly. In 1915 the South Georgia Whaling Company (Messrs. Salvesen, Leith) captured 1085 whales, consisting of 15 percent humpback, 25 percent fin whales, 58 percent blue whales, and 2 right whales. In the same year the captures of three companies at the South Shetlands gave 1512 whales, and the percentages worked out at 12 percent humpbacks, 42 percent fin whales, and 45 percent blue whales. In 1919 the Southern Whaling and Sealing Company captured (at Stromness, South Georgia) 529 whales, of which 2 percent were humpbacks, 51 percent fin whales, and 45 percent blue whales. These captures do not represent the total catch, but are sufficiently reliable to show how the species are affected. The reduction in numbers of the humpback is very noticeable, and even allowing for the possible increase in size of gear for the capture of the larger and more lucrative blue and fin whales, there is sufficient evidence to warrant the fears that the humpback stock is threatened with extinction.
In the immediate northern areas—in the region from latitude 50º S. northward to the equator, which is regarded as next in importance quantitatively to the sub-Antarctic, though nothing like being so productive, the captures are useful for a comparative study in distribution. At Saldanha Bay, Cape Colony, in 1912, 131 whales were captured and the percentages were as follows: 36 percent humpback, 13 percent fin whale, 4 percent blue whale, 46 percent sei whale; while nearer the equator, at Port Alexander, the total capture was 322 whales, and the percentages gave 98 percent humpback, and only 2 captures each of fin and sei whales. In 1914, at South Africa (chiefly Saldanha Bay and Durban), out of a total of 839 whales 60 percent were humpback, 25 percent fin whales, and 13 percent blue whales. In 1916, out of a total of 853 whales 10 percent were humpback, 13 percent fin whales, 6 percent blue whales, 68 percent sperm whales, and 1 percent sei whales. In Chilean waters, in 1916, a total of 327 whales gave 31 percent humpbacks, 24 percent fin whales, 26 percent blue whales, 12 percent sperm whales, and 5 right whales. There seems then to be a definite interrelation between the two areas. The same species of whales are captured, and the periods of capture alternate with perfect regularity, the fishing season occurring from the end of November to April in the sub-Antarctic and from May to November in the sub-tropics. A few of the companies, however, carry on operations to a limited extent at South Georgia and at the Falkland Islands during the southern winter, but the fishing is by no means a profitable undertaking, though proving the presence of whales in this area during the winter months.
The migrations of whales are influenced by two causes:
1. The distribution of the food supply.
2. The position of their breeding grounds.
In the Antarctic, during the summer months, there is present in the sea an abundance of plant and animal life, and whales which feed on the small
plankton
organisms are correspondingly numerous, but in winter this state of things is reversed, and whales are poorly represented or absent, at least in the higher latitudes. During the drift of the
Endurance
samples of
plankton
were taken almost daily during an Antarctic summer and winter. From December to March, a few minutes’ haul of a tow net at the surface was sufficient to choke up the meshes with the plant and animal life, but this abundance of surface life broke off abruptly in April, and subsequent hauls contained very small organisms until the return of daylight and the opening up of the pack ice. The lower water strata, down to about 100 fathoms, were only a little more productive, and
Euphausiæ
were taken in the hauls—though sparingly. During the winter spent at Elephant Island, our total catch of gentoo penguins amounted to 1436 for the period April 15 to August 30, 1916. All these birds were cut up, the livers and hearts were extracted for food, and the skins were used as fuel. At the same time the stomachs were invariably examined, and a record kept of the contents. The largest proportion of these contained the small crustacean
Euphausia,
and this generally to the exclusion of other forms. Occasionally, however, small fish were recorded. The quantity of
Euphausiæ
present in most of the stomachs was enormous for the size of the birds. These penguins were migrating, and came ashore only when the bays were clear of ice, as there were several periods of fourteen consecutive days when the bays and the surrounding sea were covered over with a thick compact mass of ice floes, and then penguins were entirely absent.
Euphausiæ,
then, seem to be present in sufficient quantity in certain, if not in all, sub-Antarctic waters during the southern winter. We may assume then that the migration to the south, during the Antarctic summer, is definitely in search of food. Observations have proved the existence of a northern migration, and it seems highly improbable that this should also be in search of food, but rather for breeding purposes, and it seems that the whales select the more temperate regions for the bringing forth of their young. This view is strengthened by the statistical fetal records, which show that pairing takes place in the northern areas, that the fetus is carried by the mother during the southern migration to the Antarctic, and that the calves are born in the more congenial waters north of the sub-Antarctic area. We have still to prove, however, the possibility of a circumpolar migration, and we are quite in the dark as to the number of whales that remain in sub-Antarctic areas during the Southern winter.
The following is a rough classification of whales, with special reference to those known to occur in the South Atlantic:
The subdivision of whalebone whales is one of degree in the size of the whalebone. These whales have enormously muscular tongues, which press the water through the whalebone lamellae and thus, by a filtering process, retain the small food organisms. The food of the whalebone whales is largely the small crustacea which occur in the
plankton,
though some whales (humpback, fin whales, and sei whales) feed also on fish. The stomachs examined at South Georgia during December 1914 belonged to the three species, humpbacks, fin whales, and blue whales, and all contained small crustacea
—Euphausiæ,
with a mixture of
Amphipods.
The toothed whales—sperms and bottlenoses—are known to live on
squids,
and that there is an abundance of this type of food in the Weddell Sea was proved by an examination of penguin and sea stomachs. Emperor penguins (and hundreds of these were examined) were invariably found to contain
Cephalopod
“beaks,” while large, partly digested
squids
were often observed in Weddell seals. A dorsal fin is present in the rorquals but absent in right whales. With other characters, notably the size of the animal, it serves as a ready mark of identification, but is occasionally confusing owing to the variation in shape in some of the species.
With the exception of several schools of porpoises very few whales were seen during the outward voyage. Not till we approached the Falkland area did they appear in any numbers. Four small schools of fin whales and a few humpbacks were sighted on October 28 and 29, 1914, in lat. 38º 01’ S., long. 55º 03’ W., and in lat. 40º 35’ S., long. 53º 11’ W., while
Globicephalus melas
was seen only once, in lat. 45º 17’ S., long. 48º 58’ W., on October 31, 1914. At South Georgia the whales captured at the various stations in December 1914 were blue whales, fin whales, and humpbacks (arranged respectively according to numbers captured). During the fishing season 1914- 15 (from December to March) in the area covered—South Georgia to the South Sandwich Islands and along Coats’ Land to the head of the Weddell Sea—the records of whales were by no means numerous. Two records only could with certainty be assigned to the humpback, and these were in the neighborhood of the South Sandwich Islands. Pack ice was entered in lat. 59º 55’ S., long. 18º 28’ W., and blue whales were recorded daily until about 65º S. Between lat. 65º 43’ S., long. 17º 30’ W., on December 27, 1914, and lat. 69º 59’ S., long. 17º 31’ W., on January 3, 1915, no whales were seen. On January 4, however, in lat. 69º 59’ S., long. 17º 36’ W., two large sperm whales appeared close ahead of the ship in fairly open water, and were making westward. They remained sufficiently long on the surface to render their identification easy. Farther south, blue whales were only seen occasionally, and fin whales could only be identified in one or two cases. Killers, however, were numerous, and the lesser piked whale was quite frequent. There was no doubt about the identity of this latter species as it often came close alongside the ship. From April to September (inclusive) the sea was frozen over (with the exception of local “leads”), and whales were found to be absent. In October whales again made their appearance, and from then onwards they were a daily occurrence. Identification of the species, however, was a difficult matter, for the
Endurance
was crushed and had sunk, and observations were only possible from the ice floe, or later on from the boats. The high vertical “spout” opening out into a dense spray was often visible, and denoted the presence of blue and fin whales. The lesser piked whale again appeared in the “leads” close to our “camp” floe, and was easily identified. An exceptional opportunity was presented to us on December 6, 1915, when a school of eight bottlenose whales
(Hyperoodon rostratus)
appeared in a small “pool” alongside “Ocean” Camp in lat. 67º 47’ S., long. 52º 18’ W. These ranged from about 20 ft. to a little over 30 ft. in length, and were of a uniform dark dun color—the large specimens having a dull yellow appearance. There were no white spots. At the edge of the pack ice during the first half of April 1916, about lat. 62º S. and long. 54º W. (entrance to Bransfield Strait), whales were exceedingly numerous, and these were chiefly fin whales, though a few seemed to be sei whales. It is interesting to note that the fishing season 1915-16 was exceptionally productive—no less than 11,860 whales having been captured in the Falkland area alone.
The South Atlantic whaling industry, then, has reached a critical stage in development. It is now dependent on the captures of the large fin and blue whales, humpbacks having been rapidly reduced in numbers, so that the total stock appears to have been affected. With regard to the other species, the southern right whale has never been abundant in the captures, the sperm whale and the sei whale have shown a good deal of seasonal variation, though never numerous, and the bottlenose and lesser piked whale have so far not been hunted, except in the case of the latter for human food. The vigorous slaughter of whales both in the sub-Antarctic and in the sub-tropics, for the one area reacts on the other, calls for universal legislation to protect the whales from early commercial extinction, and the industry, which is of worldwide economic importance, from having to be abandoned. The British Government, with the control of the world’s best fisheries, is thoroughly alive to the situation, and an Inter-departmental Committee, under the direction of the Colonial Office, is at present devising a workable scheme for suitable legislation for the protection of the whales and for the welfare of the industry.