Feeding ecology of eastern North Pacific killer whales Orcinus orca from fatty acid, stable isotope, and organochlorine analyses of blubber biopsies

摘要: Blubber biopsy samples from eastern North Pacific killer whales Orcinus orca were ana- lyzed for fatty acids, carbon and nitrogen stable isotopes organochlorine contaminants. Fatty acid profiles sufficiently distinct among the 3 reported ecotypes ('resident,' 'transient' or 'offshore') to enable individual animals be correctly classified by ecotype also mitochondrial DNA (mtDNA) haplotype. Profiles of PCBs enabled unambiguous classification all whale ecotypes, but isotope values lacked sufficient resolution. acid, PCB resident transient consistent with those expected these based on their dietary preferences (fish whales, marine mammals transients). In addition, exhibited broad similarity across geographical regions, suggesting that specialization in well-studied populations extends less-studied western Gulf Alaska Aleutian Islands. Killer same grouped region sample col- lection. The mean ratios various regional groups differed considerably, prey may both spe- cific. Furthermore, specific found have measured literature. Finally, although offshore population had blubber implicating fish as its primary prey, contaminant results equally congruent predation mammals.