POPULATION STUDIES ON THE MINKE WHALE 165 



Fig. 4 shows the percentage of mature minke whales in the catches in each 

 of the seasons 1938-58. From 1938 to 1944, this percentage decreased from 

 42-8 to 18-3, increased again to 42-9 in 1949, decreased to 27-7 in 1950, 

 increased to 38-9 in 1952, and decreased fmally to 30-8 in 1953. From then 

 on, there has been a continuous and even increase, and in 1958 the percentage 

 of mature animals reached 43 • 2, which is the maximum for the twenty-one 

 years covered by our statistics. 



The decrease from 1938 to 1944 coincide with the period in which the 

 Lofoten area was the most important whaling field. It would, consequently, 

 be reasonable to expect that the percentage of mature animals in the catches 

 from Lofoten would have a decisive influence on the percentage in the total 

 catches. 



The percentage of mature animals in the Lofoten catches decreased by 

 9-9 per cent from 1938 to 1944, and this decrease can be attributed to a 

 relative increase in the number of whales caught in this area in the summer 

 months, when calves are most abundant. Simultaneously, there was an 

 increased intensity of whaling in this area, which was partly local, but to a 

 great extent due to increased participation of whalers from other coastal 

 areas. As a consequence of this last shift, the relative importance of the 

 Lofoten catches increased from 38-3 per cent of the total in 1938 to 65-2 per 

 cent in 1944. An increase in relative importance of this magnitude must in 

 turn reduce the percentage of mature animals in the total catches. 



As previously mentioned, the catches in Arctic waters increased con- 

 siderably after the war, and since large-sized animals are more abundant 

 there than in Norwegian coastal waters, the percentage of mature animals 

 in the total catches increased accordingly. The variations observed in the 

 percentage of mature animals in the period from 1944 to 1953, are, therefore 

 mainly due to variations in the Arctic contributions to the total catches. 



The continuous and even increase from 1953 to 1958 in the percentage of 

 mature animals in the total catches, corresponds to a similar increase in the 

 Arctic catches, from 49*0 per cent in 1953 to 61 -8 per cent in 1958. A trend 

 to increasing percentages of mature animals is also apparent in the catches 

 from the Lofoten area in this same period. In all other areas considered 

 together, a definite increase in the percentage of mature animals is observed, 

 namely from 18-4 per cent in 1953 to 43-6 in 1958. For this part of the 

 catches, some of the increase may be attributed to greater catches taken off 

 Scotland, Shetland and the Faroes, where many big whales are met with. 

 Summarizing these observations, it must be concluded, however, that a 

 general increase in the percentage of mature animals has occurred since 1953 

 within the whole catch. 



During all seasons of which we have statistics, the minke whales have been 



