WHALES AND THEIR FOOD.

Waimate Daily Advertiser, Volume XXIV, 4 January 1929, Page 2

WHALES AND THEIR FOOD.

AN ANTARCTIC INVESTIGATION

In the journal of the Royal Geographical Society for September appears a paper bj' Professor A. C. Hardy, who was a member of the

scientific staff of the Discovery on two oceanagraphic expeditions to the Antarctic, outlining the work of these expeditions. Professor Hardy says that it was not until 1854 that the first samples were

brought up from the seabed. At that time a theory that life did not exist below 300 fathoms was strongly supported. While the dredges of numerous expeditions revealed the life of the ocean floor, tow’-nets disclosed hosts of minute animal and vegetable organisms in the upper layers of the water. This type of life was exhaustively studied in 1887 by Hensen, who termed all these passively drifting organisms as “plankton.” The sea is one great culture medium, through it is scattered a fine acquatic dust, untold billions of microscopic, single-celled plants known as diatoms, which form the food of the planktons. The plankton (“drifting”) animals are of tremendous importance to marine zoology. They form the principal food of pelagic fish, such as herring, pilchard, and mackerel, and the great whalebone whales. Of herrings alone some 10,000,000,000 are landed in England annually from the North Sea, and the number can be only a small proportion

of the total supply. If we can imagine these as land animals sweeping across a continent, and devastating the vegetation of the countryside, the tremendous quantity of food required may be faintly imagined. From the North Sea alone 1,500,000 tons of fish are taken every year, and from the Falkland Island dependencies 250,000 and 500.000 barrels of whale

This immense drain on sea life, though small in comparison with the .whole, has led to the study of the food and its distribution. Since 1904 there has been great activity in whaling in South Georgia and the South Shetlands. The whales taken are the blue and fin whales, and the humpback. They are all toothless, and all plankton feeders. The grounds are controlled by the British Government. Until 1915 the - number of fishing licenses issued to Norwegians principally, was strictly limited. During the war, however, when the demand for glycerine was urgent, restrictions were relaxed. Since then, in a single season, as many as 11,792 whales have been taken. The extent of the killing has been so great that the Government has become alarmed. Fears have been expressed that unless whale hunting be restricted, the southern seas may become as cleared of whales as have the northern seas. One of the duties of the scientists on the Discover.;' was to study the life history of the whale, and its migration, and to accumulate all data that would be a guide to the preservation and protection of the species. The only protection at present lies in the fact that the rorqual will not be exterminated because before that point is reached the industry will not be commercially remunerative.

The Discovery was accompanied by another research ship, the William Scoresby. The two vessels worked in conjunction through two seasons. Professor Hardy graphically describes the research work among the phosphorescent organisms in tropical waters on the voyage southward. Shore stations had been previously established at South Georgia, where, amid the un-

pleasant surroundings of a whaling station, detailed measurements of 1600 whales were made, and other observations gave for the first time much-needed information concern-

ing the breeding time, the rate of growth, and the age of maturity. Special study was made of the food of whales, so that much valuable groundwork had been done when the Discovery arrived. Among other work undertaken was that of w’hale marking. Whales migrate, but very little is known of their movements. There is a spring migration to polar waters rich in plankton, and an autumn movement to warmer waters for breeding, but many problems of the migration remain to be solved, and it is hoped by marking to obtain information. The marking is carried out by shooting a “mark pin” into a whale’s blubber. The “mark pin” resembles a large drawing pin, and is made of silver-

plated rustless steel. It bears upon its disc a number and direction for its return from a whaling station where it may be found. The pin is heavily barbed to hold it in the blubber, and is fired into the whale from a light shoulder gun. Leaflets are distributed to stations all over the world offering a reward for the return of the mark pin. As this method of marking has proved very successful in ascertaining the movements of fish, it is hoped that similar results will attend its use with whales. The importance of the work in the vicinity of South Georgia arises from the peculiar formation of the island. It is some 100 miles long by about 15 miles wide, and lies almost at right angles to the main drift coming up from Drake Straits. The currents tend to set round it as they would set round any long object forced through fluid sideways. The water is forced in a curve round either end to meet in an eddy some distance behind it. This has the effect of leaving an area of dead water immediately against the land. Where the main current strikes the continental shelf of South Georgia there will be an unveiling of water rich in phosphate from the deeper layers. It is here is found the densest growth of diatoms, which are carried round either end into the dead water behind the island. In this sheltered water are all the planktons which

feed directly on the diatoms. It is a sheltered nursery for the whales’ food, and for this reason should be one of the richest whale-feeding grounds in the world.

With South Georgia as a centre a systematic survey was made of the whaling grounds. The most elaborate and detailed examination was made of the water from the surface down to about 6000 feet.

Temperature and analysis tests were made, but the closest atten-

tion was given to the supply of plankton. Professor Hardy invented an instrument that was lowered from the ship and.gave a complete and continuous record of the plankton distribution over the ship’s

course, instead of only in spots as had hitherto been the case. The expedition covered a tremendous area of ocean. Taking in South Georgia, the Falklands, and the South Shetland groups, it visited Deception Island in the South Shetlands, where the harbour is a circular flooded volcano with only one entrance. Here floating factories shelter from the heavy weather. In spite of its proximity to the Antarctic, the beach is hot and the water steamy. During volcanic activity in 1924 it is said that for a short time the water actually boiled. The specimens of water and life obtained during the expedition reached a very large number. Scientists are still at work in England completing their investigation and correlating the results.