360 



DISCOVERY REPORTS 



age classes have been determined. These are given in Table III, in which it will be 

 noticed that the only actual figures are those in column 2, those in columns 3-8 being 

 theoretical. It will be seen how closely the theoretical catches in column 3 agree with 

 the actual catches in column 2. By extending the series backwards for one term the 

 theoretical catch and stock of immature whales have been determined. 



Table III 

 Female Fin whales 



* Figures based on the assumption that the normal rate of reduction (26 per cent) is continued with the 

 older whales. 



Column 5 shows the numbers of whales in each age class that are not caught (stock 

 minus catch). As far as the 13-14 year class the calculated stock in each age group 

 is the same as the number of whales surviving in the previous age group. Beyond the 

 13-14 year class, where the series no longer holds, the stock has been calculated from 

 the individual figures of the catch on the assumption that the catch is 26 per cent of the 

 stock, and the figures obtained, by subtraction from the surviving stock of the previous 

 age group, lead directly to the numbers of whales that have disappeared. It should be 

 remembered that the whales missing from one age group do not appear in the stock of 

 the next group. The numbers of missing whales are shown in column 6 (column 5 

 minus the next line of column 4). The absence of about half the older stock (52, 48 and 

 46 per cent are the figures) is a curious phenomenon whose implications have already 

 been remarked upon. 



