326 \VHALES 



that direction. Since, however, the number of Bhie Whales caught 

 annually has decreased so greatly over the past fifteen years that nowadays 

 Blue Whales represent a mere 4-5 per cent of the total catch, this factor 

 cannot influence the yield to any large extent. It might also be argued that 

 the statistics are affected by characteristic differences in length betw^een 

 specimens in different zones, since the bigger a whale the larger, of course, 

 its yield of oil, a factor which the definition of the B.W.U. does not take 

 into consideration. Ho^vever, no such marked differences have ever been 

 recorded. 



To overcome all these statistical difficulties, C. E. Ash, the Balaena 

 chemist, has tackled the entire subject in a completely fresh manner. He 

 expressed the yield in barrels per total weight of whale instead of per 

 B.W.U. , the weight having first been calculated from the length by using 

 a formula which was established as a result of a great number of measure- 

 ments and weighings, largely carried out by Japanese biologists. In this 

 way, Ash calculated that, for the years 1947 to 1951, the oil yield per 

 total weight was: Aiea II - 24-6 per cent. Area III - 22 -5 per cent. Area 

 IV - 22 -8 per cent, and Area V - 21 -2 per cent - a significant decrease 

 from west to east. (Though different factory ships manage to extract 

 different quantities of oil from the B.W.U., due to differences in technique, 

 these differences do not affect Ash's figures to any significant extent.) 



There is other evidence as well that whales in the western zones are 

 fatter than those in the east, viz. the chemical composition of their oil. 

 Whale-oil, like most fats, is a compound of glycerol and fatty acids. Now, 

 fatty acids are either saturated (e.g. palmitic acid) or else unsaturated 

 (e.g. oleic acid) when they can add on other hydrogen atoms until satura- 

 tion is reached. The extent to which unsaturated acids are present in 

 oils or fats is given by their iodine number or value, which expresses the 

 number of grams of iodine absorbed by 100 grams of oil or fat under 

 certain conditions. Thus the higher the iodine number, the greater the 

 percentage of unsaturated fatty acids. 



Now, the Norwegian chemist, J. Lund, who has made a very long and 

 detailed study of the iodine number of the oil obtained from various 

 whaling areas, discovered, inter alia, that marked differences in this 

 number are found in various parts of the North Atlantic (Norway, Spain, 

 Newfoundland). Such differences are also found in the Antarctic, where 

 the iodine number decreases perceptibly from west to east. Moreover, 

 Lund established that the iodine number in a given area increases in the 

 course of the season as the whales grow fatter. A low iodine number, 

 therefore, seems to go hand in hand with a low oil yield and from it we can 

 thus adduce additional evidence that whales have less fat in the east than 

 in the west. Another factor influencing these differences may well be 



