THE FUTURE OF WHALES AND WHALING 



397 



Figure 2ig. Number of Blue Whale Units caught by Antarctic factory ships per Catcher's 

 Day's Work from ig4y-ig§g. {From data supplied by International Whaling Statistics.) 



whales has increased in recent years, it does not a fortiori entitle us to say 

 that the number has diopped.^) 



One argument that has been cited in favour of a drop in population is 

 the decrease in average length of the annual catch and the increase from 

 13-8 per cent to 30 per cent of the proportion of sexually immature 

 animals in it. In fact, the average length of captured Fin Whales has 

 decreased from 67 -9-66 -8 feet since 1947-8 (with the exception of the 

 'fat years', i.e. 1951 and 1952 when it was back to normal). Now an 

 increase in the proportion of young animals in the catch may be inter- 

 preted with equal justification as a sign of decimation of the adult 

 population, as of an increase in propagation. Moreover, by virtue of the 

 international overall catch limit of a fixed number of vmits, competition is 

 naturally increased, with the result that every expedition will try to bag 

 as much of the total quota as quickly as it can. This causes an increase of 

 the number of catchers per factory ship and consequently an increase of 

 competition between the catchers. There is no time for selecting large 

 animals only. Now we saw on p. 184 that younger animals are less 

 experienced and more inquisitive than adults, and are therefore more 

 easily caught (which applies also to different types of game). Thus 

 Arseniev (1958) reported Russian gunners as stating that adult Rorquals 

 are not only more difficult to approach than immature animals, but that 

 they become more and more suspicious as the season advances. 



1 In the seasons 1959-60 and 1960-61 the figures for B.W.U. per C.D.VV. were extremely 

 low (0.72 and 0.68). On the other hand, catching conditions were quite abnormal because 

 there was no overall limit and because many expeditions reported extremely bad weather. 

 Meanwhile a small body of experts on fishery statistics has started to study the problem 

 on a new basis. 



