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Project Information

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

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

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.


Geographic Regions Prince William Sound
Species Marine Mammals - Pinnipeds (seals, sea lions, walrus)
Fields of Expertise Ecology

Proposal: PDF Not Available

Funding Recommendations: View

Funding Detail For: 1993

Quarterly Project Tasks For: 1993

Annual Report: 1993: View (3,319 KB)

Final Report: See Project 433

Publications from this Project: None Available

More information may be available for this project under other years:

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Project Number Proposal Annual Reports Final Report Data
2001: 01064-CLO View (PDF) 2001: Not Available
View No datasets
2000: 00064-CLO Not Available 2000: Not Available
See Project 01064-CLO See Project 01064-CLO
1999: 99064 Not Available 1999: Not Available
See Project 01064-CLO See Project 01064-CLO
1998: 98064 Not Available 1998: View (PDF)
See Project 01064-CLO See Project 01064-CLO
1997: 97064 Not Available 1997: View (PDF)
See Project 01064-CLO See Project 01064-CLO
1996: 96064 Not Available 1996: View (PDF)
See Project 01064-CLO See Project 01064-CLO
1995: 95064 Not Available 1995: View (PDF)
See Project 01064-CLO See Project 01064-CLO
1994: 94064 Not Available 1994: View (PDF)
See Project 01064-CLO See Project 01064-CLO
1992: R073 Not Available 1992: Not Applicable
See Project MM05 See Project MM05
1992: MM05 Not Available 1992: Not Applicable
View No datasets
1991: MM05 Not Available 1991: Not Applicable
See Project MM05 See Project MM05
1990: MM05 Not Available 1990: Not Applicable
See Project MM05 See Project MM05
1989: MM05 Not Available 1989: Not Applicable
See Project MM05 See Project MM05