-36- 



6) Minke Whale 



Data on the entire southern minke whale population 

 do not appear to support or contradict the existence of 

 separate stocks. 



d. Standing Stock 



Standing stock estimates for Antarctic whales are not 

 easily made. Information used for this purpose includes 

 sighting records, catch per unit effort, reproductive para- 

 meters, mortality rates and mark-resight data on movements 

 (Mackintosh, 1970) . Gambell (1976e) discusses methods of 

 estimating standing stocks of whales including sighting, 

 marking, recruitment curve methods, mortality and catch- 

 ability, least squares method, and the DeLury Method. 



Various standing stock estimates for Southern Ocean 

 baleen and sperm whales appear in Tables 5 and 6. Present 

 and initial stock estimates of minke whales are close be- 

 cause minke whales were largely unexploited before 1971. 

 According to Mackintosh (1972), less than 100 minke whales 

 were taken annually until 1971, when 3,000 were taken. 



Because of limited commercial interest in minke whales, 

 information on this species is limited in comparison to 

 other Southern Ocean baleen whales. Without more data, it 

 is not possible to develop estimates with a high degree of 

 confidence. Moreover, it is unclear how large the historic 

 stocks of minke whales were prior to intensive harvest of 

 the great whales in the Southern Ocean. Since population 

 estimates have only been made in the last decade, estimates 

 of pre-exploitation abundance are not good. It may be that 

 the current minke whale populations exceed pre-exploitation 

 levels. This possibility is discussed in a later section. 



As shown in Figure 5, most species abundance estimates 

 are within a reasonable interval of each other. An exception 

 is Laws' (1977a) estimate for initial sei whale stocks which 

 he puts at 75,000 individuals, roughly half other estimates. 

 This is explained by Laws' conclusion that 75,000 individuals 

 actually fed south of the Convergence while other estimates 

 may have included Southern Hemisphere individuals which did 

 not spend major time feeding south of the Convergence. In 

 general, when abundance estimates are made for whales in the 

 Southern Hemisphere, there are at least three levels for 

 which estimates of whale abundance in the Southern Hemi- 

 sphere are made: 1) the entire Southern Hemisphere, 

 2) south of 40° S, and 3) south of the Antarctic Convergence. 

 Although most of the figures in Table 5 were chosen as those 

 referring to abundances south of the Convergence, some may 

 have incorporated larger areas. Gambell (1975c) pointed out 



