Project Information

Title: Habitat Use, Behavior, and Monitoring of Harbor Seals in PWS 93046

Project Year and Number: 1993: 93046

Other Fiscal Years and Numbers for this Project: 2001: 01064-CLO, 2000: 00064-CLO, 1999: 99064, 1998: 98064, 1997: 97064, 1996: 96064, 1995: 95064, 1994: 94064, 1992: R073, 1992: MM05, 1991: MM05, 1990: MM05, 1989: MM05

Principal Investigator (PI): Kathy Frost (Alaska Department of Fish & Game)

Managing Agency: ADFG

Assisting Personnel: Sara Iverson, Lloyd Lowry, Mike Simpkins, Jay Ver Hoef

Research Location: Prince William Sound

Restoration Category: Monitoring

Injured Resources Addressed: Harbor Seals, Recreation & Tourism, Subsistence

Abstract: Harbor seals (Phoca vitulina) occur year round in Prince William Sound (PWS) where they often haul-out on rocks, reefs, beaches, and glacial ice. They pup, breed, molt, and feed in the Sound. During extensive surveys of PWS in 1991, 2500-3000 harbor seals were counted on haul-outs. Another 1700 were counted in the Copper River Delta and Orca Inlet. This under estimates the population since some seals were in the water and some small haul outs were not surveyed. From 1984 to 1988, harbor seal numbers at trend sites in PWS declined by 43% for unknown causes. The decline continued in 1989 to 1990, exacerbated in oiled areas by the Exxon Valdez oil spill (EVOS); 1990 counts were 57% lower than in 1984. Following the oil spill, counts of harbor seals at oiled trend count sites declined by 35%, compared to 13% at unoiled sites, indicating a reduction of about 20% at oiled haul-outs. It is likely that over 200 harbor seals were killed by the EVOS in PWS. Although molting surveys in 1991 suggested that numbers might be increasing, pupping counts were 10% lower in 1992 than in 1991. Whether there are long term effects is unknown. Harbor seals are important to residents of PWS for subsistence. In 1987 to 1989, they made up 13%-19% of the total harvest of subsistence foods in Tatitlek. In Chenega Bay in 1985-1986, harbor seals accounted for 27% of the total pounds harvested. Harbor seals are also watched by commercial fisheries. Like all marine mammals, they have special federal protection under the Marine Mammal Protection Act. If the current decline continues or if up to date population data are not available, harbor seals could be placed in a more restrictive legal classification. The proposed study will take place in PWS. The information obtained will benefit residents of Tatitlek, Chenega Bay, and other PWS communities who use harbor seals for subsistence, and tourists and other recreational users by providing information on trends in abundance, biology of the seals, and insight into possible causes for the ongoing decline. Data will benefit PWS fishermen by ensuring that restrictive measures regarding incidental take of harbor seals are not implemented unnecessarily due to lack of data. Information contributed by this study may lead to management recommendations which will ensure that human activities do not have further impacts on harbor seals.


Proposal: Not Available

Reports:
Annual Report FY93: View (3,241 KB)
Final Report: Final Report Not available. For current status, please contact us.

Publications from this Project: None Available

Datasets:
EVOSTC Data Archive: Survey counts, location and dive data, fatty acid composition of prey and blubber. Tables, Graphs, Maps, Diskette. Availability: Upon request.