Impact of Killer Whale Predation on Harbor Seals in Prince William Sound: APreliminary Assessment of Diet Using Stable Isotope and Fatty Acid Signature Analysis on Blubber Biopsies. Restoration Project 96012A-2. EXXON VALDEZ Oil Spill. Restoration Project

摘要

In Prince William Sound, predation by killer whales occurs on at least threeinjured resources: harbor seals (Phoca vitulina), salmon (Onchorhynchus sp), and herring (Clupea pallasi). To predict the relative impact that killer whale predation may have on these injured resources, the level of predation and the relative proportion of each species consumed by killer whales must be quantified. Current information on the feeding habits of killer whales are based either on observatons of feeding events or examination of stomach contents of stranded whales. The current paradigm is that transient whales feed primarily on marine mammals and that resident whales feed on fish. The objective of the present study was to assess whether stable isotope signature analysis and fatty acid signature analyses could be applicable in the resolution of this problem. This preliminary attempt was designed to ascertain whether standard biopsy samples, which are commonly derived for genetic analysis, would be appropriate for use in the assessment of feeding habits using these techniques.