The Eastern Bering Sea Shelf : oceanography and resources / edited by Donald W. Hood and John A. Calder . easternberingsea00hood Year: 1981 856 Marine mammals water temperature undoubtedly account for much of the variation in caloric requirements. Several authors estimate feeding rates for the northern fur seal. In a preliminary report on food- chain relationships of marine mammals in Alaskan waters, Sanger (1974) assumed a consumption rate of 6 percent of body weight per day, which he charac- terized as conservative. Bigg et al. (1977, 1978) reported daily feeding rates of percent fo
The Eastern Bering Sea Shelf : oceanography and resources / edited by Donald W. Hood and John A. Calder . easternberingsea00hood Year: 1981 856 Marine mammals water temperature undoubtedly account for much of the variation in caloric requirements. Several authors estimate feeding rates for the northern fur seal. In a preliminary report on food- chain relationships of marine mammals in Alaskan waters, Sanger (1974) assumed a consumption rate of 6 percent of body weight per day, which he charac- terized as conservative. Bigg et al. (1977, 1978) reported daily feeding rates of percent for captive adult females eating frozen Pacific herring. In a paper on fur seal energetics. Miller (1977) summa- rized previous estimates of feeding rates which ranged from to 15 percent of body weight per day and, from his own data, estimated the feeding rate for a subadult 21-kg fur seal in water at 5 C as 14 percent of body weight when the food source was walleye pollock (Theragra chalcogramma). Since other fish important as prey species of the fur seal have similar caloric content and squid are only slightly lower, the 14 percent value may be considered representative for most of the fur seal's diet. McAlister and Perez (1977) estimated a mean effective daily consumption rate for fur seals in the Bering Sea and Aleutians area of percent of body weight. This estimate used Miller's consumption rate and considered the age structure of the herd, land-sea movements during the breeding season, and the seasonal distribution of the fur seal population. Using his conservative daily consumption rates and an estimated 550,000 animals feeding from June 171-OOW 57-50N 57-30N 57-OON 56-30N 56-OON 55-50N 155 154 153 152 151 150 149 148 147 146 145 -I- â I I 170-OOW 169-OOW I I â I â . I â â I â â I I â â I AUGUST SEALS PER HOUR Do , Q â¡ ^ffl R 1 âQ Q 10 or more ⢠Unit occupied for less than hour 326 325 324 323 322 321 I'll' '^ 320 319 318
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