GRANT
NUMBER:
97-NW-04
REPORT
TITLE: Pinniped-Salmonid
Co-Occurrence: Assessment of Potential Impacts of Pinnipeds
on Salmonids in Selected Estuaries
AUTHOR:
PUBLISH
DATE:
AVAILABLE
FROM:
National Marine Fisheries Service, National Program Office,
1315 East West Highway, Silver Spring, MD 20910.
TELEPHONE: (301) 713-2358
ABSTRACT
A pilot program
was conducted in the Alsea, Rogue and Umpqua Rivers in
Oregon in the fall of 1997 when pinnipeds (Pacific harbor
seals and California sea lions) were known to occur in
the mouths of these rivers during the migration of coho
salmon. Methodology included surface foraging observations
and pinniped scat collection in the Alsea and Rogue Rivers,
scat collection in the Umpqua River, and pinniped scarring
data collection at a hatchery in the Alsea River system.
The data collected during the fall season of 1997 were
determined to not be adequate for an assessment of pinniped
impacts on salmon. Investigators identified the need to
adjust and expand studies to include more observations
especially upriver in the systems, increased scat sampling,
and multi season work to address interannual variability.
