WHALE MARKING 271 



number of Humpbacks taken was more than double that of the previous season. This 

 figure was almost doubled the following season (1935-36), in spite of new regulations im- 

 posing a lower length limit of 35 ft., and was subsequently increased the next season to the 

 highest figure of 4477. The season 1937-38 saw a reduction in the numbers taken to less 

 than half this figure, coincident with a phenomenally high Fin whale catch, perhaps 

 indicating a neglect of the Humpback in favour of the larger quarry. The taking of 

 Humpbacks by pelagic factories working south of 40 ° S latitude was totally prohibited by 

 those countries who in June 1938 accepted the amendment to the international agreement 

 of June 1937. 



In addition to this great increase in the persecution of Humpback whales on the 

 Antarctic grounds since 1934, increased toll has been taken of them in tropical waters. 

 Whaling recommenced off the west coast of Australia in the southern winter of 1936 and 

 more than 3000 Humpbacks were killed, a number which was increased the following year. 

 Around Africa, whaling reopened off the Congo in the southern winter of 1934 and more 

 than 700 Humpbacks were taken. This figure was almost doubled the following season, 

 1935, but since then there has been a rapid decline in the season's catch. At Saldanha 

 Bay, whaling recommenced in 1936, but the catch of Humpbacks there has been 

 trifling. Since 1935, when 418 whales were taken, the Humpback catch made off the 

 Natal coast has shown a rapid and steady decline. A new ground off the southern 

 coast of Madagascar was exploited by a factory ship in 1937 and 1223 Humpbacks 

 taken; the following year the catch was increased to 1752. In 1935 whaling also 

 recommenced along the west coast of South America and has since continued, but 

 the catch of Humpbacks has been insignificant. This survey of the distribution and 

 intensity of Humpback whaling is of interest in studying the returns of marks. 



Of Humpbacks, 547 are estimated to have been effectively marked, and of these 540 

 were marked by the ' William Scoresby ' on the Antarctic pelagic whaling grounds ; the 

 remaining seven have been marked around South Georgia. Of those marked by the 

 'William Scoresby' the majority were found on the most easterly grounds visited, 

 between 80 and 1 io° E, where they were met with in considerable numbers. It is from 

 the whales marked in this region that the largest number of recoveries have been made. 

 A number of Humpbacks have also been marked to the westwards of Enderby Land, 

 south of Africa, and in the Bellingshausen Sea. 



Five whales constitute the o-Group (Table IV), and these show only small movements. 

 Of sixty-eight Humpbacks marked by the 'William Scoresby' in 1934-35, one (No. 

 3129/38) on the Enderby Land ground was recovered after five days a short distance to 

 the south (Plate LXII). In 1935-36, one of four marked near South Georgia was 

 captured after six days, and this showed a movement of 1 16 miles to the northward. In 

 the following season, three whales marked off Queen Mary Land were captured after 

 an average interval of twenty-one days. The distances traversed were small and were in 

 directions to the south and south-east. 



The most interesting recoveries of marks have been from those whales taken in the 

 southern winter in warmer waters away from the Antarctic. The ^-Group contains eight 



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