322 WHALES 



these statistics, we also have data on the number of whales observed from 

 research ships cruising in various parts of the Antarctic Ocean. The 

 Norvegia, for example, patrolled the Antarctic during the entire 1 930-1 

 season, and the Discovery //made regular observations from 1933 to 1939, 

 which are compiled in the chart reproduced in Fig. 180. 



From all the facts and figures, it appears that by far the largest number 

 of whales occurs betAveen 20° and 70° W. (south of the Atlantic), between 

 20° and 40° E. (south of Africa), between 80° and 1 10° E. (south-west of 

 Australia), between 150° and i7o°E. (south-east of Australia), between 

 160° and 140° W. (south-east of New Zealand) and between 110° and 

 70° W. (south-west of South America). The number of animals caught or 

 observed in the remaining regions and especially between 50° and 70° E. 

 (south of the Indian Ocean) and between 140° and 1 10° W. (south of the 

 Pacific) is very small, in comparison. From Figs. 178, 179, and 180 we 

 can easily tell that the distribution of krill coincides largely with the dis- 

 tribution of whales, so that we are safe in saying that the latter is governed 

 by the former. Where krill is scarce, whales' stomachs are often empty, 

 and we may assume that most whales merely cross these regions in search 

 of better hvmting grounds. According to Beklemishev (i960) the distribu- 

 tion of krill depends on the occurrence of cyclones, causing upwelling water 

 in which the younger stages of krill are brought to the surface. Centres of 

 cyclonic activity appear to coincide with the occurrence of the largest 

 numbers of whales, especially Blue Whales, which feed mainly on young 

 krill. 



The above remarks apply primarily to Blue and Fin Whales, whereas 

 the distribution of Humpbacks is known to be confined to even more 

 limited regions south of South America, the Atlantic Ocean, South 

 Africa, West Australia, East Australia and New Zealand (Fig. 181). The 

 explanation for this phenomenon is, as we shall see below, that the Hump- 

 back spends the southern winter mainly off the warmer coasts and also 

 migrates up and down these coasts, while Fin and especially Blue Whales 

 seem mainly to winter in, or at least to migrate over, the high sea. Thus 

 the distribution of Humpback Whales is governed not only by the presence 

 of krill but also by the position of the mainland, while that of Blue and 

 Fin Whales probably depends far more on the density of their food. Sperm 

 Whales are caught chiefly to the south of the Atlantic Ocean and south 

 of Africa, but little more is known about their distribution in the Antarctic 

 Ocean. 



For statistical purposes, the Antarctic whaling grounds have been 

 divided into six areas (see Fig. 181), viz. Area I: i20°W.-6o°W. (the East 

 Pacific Area); Area H: 60'' W.-o° (Greenwich) (the Atlantic Area); 

 Area HI : 0^-70° E. (the African Area) ; Aiea IV: 70° E.-i30° E. (the W. 



