Monitoring, habitat use, and trophic interactions of harbor seals in Prince William Sound. Exxon Valdez Oil Spill Restoration Project Anual Report (Restoration Project 95064)
Frost KJ, Lowry LF, Small RJ, Iverson SJ. 1996. Monitoring, habitat use, and trophic interactions of harbor seals in Prince William Sound. Exxon Valdez Oil Spill Restoration Project Anual Report (Restoration Project 95064). Alaska Department of Fish and Game, Division of Wildlife Conservation. Fairbanks, AK
Restoration studies of harbor seas, Phoca vitulina richardsi, that began in Prince William Sound (PWS) in 1991 were continued in 1995. When corrected for effects of datae, time of day, and time relative to low tide, aerial survey counts of 25 trend sites during 1989-1995 showed significant declines in the number of seals during the molt (19%) and during pupping (31%). Molt counts in 1995 were higher than in 1994 (16%), while pupping counts were lower (12%). A Leslie matic population model showed that large changes in vital parameters of PWS seals must have occurred to cause the 1984-1989 decline in numbers. Preliminary results indicate that projectsion for population recover will depend on the carrying capacity level and the pattern of density dependence assumed in the model. Forty-two seals were captured and asmpled in 1995, and staellite-linked depth recorders were attached to 14. Tagged seals were tracking for up to 267 days. Most seals stayed withinPWS near the cature site, but one moved to Middleton Island and another to Yakutat Bay. Analysis of these data combined with resutls from 1992-1994 indicate that seals show considerable fidelity to haulout sites and tend to haul out more regularly during May-July. Diving behavior was ver varialbe among individuals. Seals taht moved out of PWS mad longer feeding trips (up to 20 days) than those that stayed within the Sound. Fatty acid analyses found differentces in seal prey by species, area, and season. Fatty Acid signatures indicated differences in seal diets between southeast Alaska, Kodiak and PWS, as well as between areas within PWS.
- Type
- Published Report
- Authors
- Frost, Kathryn; Lowry, Lloyd; Small, Robert; Iverson, Sara
- Date of Issue
- 1996
- Publisher
- Alaska Department of Fish and Game, Division of Wildlife Conservation
- Units
- KEFJ
- Keywords
- Behavior, diving, EVOS, Exxon Valdez Oil Spill, fatty acids, Habitat Use, Harbor Seals, Monitoring, Phoca vitulina richardsi, population modeling, Population Monitoring, Prince William Sound, Recovery, Satellite Telemetry, trophic interactions