Fatty acid composition of blubber from the four species of Bering Sea phocid seals

Abstract

The fatty acid composition of blubber lipid was analyzed from one example of both sexes of the four species of phocid seals inhabiting the Bering Sea: spotted seal (Phoca vitulina largha), ringed seal (P. hispida), ribbon seal (P. fasciata), and bearded seal (Erignathus barbatus). All specimens had similar fatty acid complements (10 fatty acids predominated, ranging from chain lengths of 14 to 22 carbons with zero lo six double bonds) although there were specific differences among species and between sexes. The greatest interspecific differences in blubber fatty acid composition occurred in the ringed seal and may have been due to diet.Double-bond indices (indicating degree of unsaturation) were high in all samples and higher than those calculated for Atlantic or southern hemisphere seals. Melting points of the blubber lipid ranged from −2 to −8 °C for some components; all components melted below 15 °C correlating with expected peripheral blubber temperatures of seals in cold water of the Bering Sea.