THE STOCK OF WHALES 



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found in the reduction of the Antarctic catches of this species relative to the catches of 

 others, in spite of the fact that it is the most profitable species. This is partly due to the 

 fact that in recent years the prescribed whaling season has not begun before December, 

 while most Blue whales are found in the early part of the season. But in the Inter- 

 national Statistics it is pointed out that the same reduction is apparent in the catches for 

 separate months. Since the opening and closing dates of the season have varied a little 

 in recent years in December and March respectively, January and February are the only 

 two months in which the percentage of each species caught is comparable year by year. 

 The figures for these months in the twelve years preceding the war are shown in 

 Table 28, and they are extracted from the International Statistics. In the earlier years 



Table 28. Annual percentage of each species in the Antarctic 

 pelagic catches, January and February 



there were considerable fluctuations in the proportion of Blue whales in the catches, 

 but on the whole it increased to a maximum in 193 1-2. Hjort, Lie and Ruud (1935, 

 p. 26) attribute this to the extension of whaling to new grounds. Since 193 1-2 there has 

 been a heavy decline, the ratio in each season nearly always being substantially lower 

 than in the preceding season. There was a slight increase in 1938-9, but it is to be sup- 

 posed that this is of no more significance than the temporary increase in January 1935 

 and February 1936. Whatever the catching capacity of the fleet, the methods of the 

 industry, or the areas in which the whaling has been conducted, it seems impossible to 

 explain so striking a change except on the grounds of a significant reduction of the Blue- 

 whale population. As Hjort, Lie and Ruud point out however (1935, p. 36), the decline 

 in the catches is not a reliable measure of the decline in the stock. It is simply evidence 

 that substantial depletion has taken place. 



Bergersen, Lie and Ruud (1939, p. 17) stress the fact also that the absolute numbers of 

 Blue whales caught has not increased in spite of the increased activity of the fleet in 

 recent seasons. 



H-2 



