Abundance, distribution, food habits and the effects of prey availability of harbor porpoise, Phocoena phocoena, in northern Monterey Bay
Barbie Byrd
Moss Landing Marine Laboratories, 8272 Moss Landing Rd., Moss Landing, CA 95039
For the last ten years, nearshore waters off Sunset Beach in northern Monterey Bay have exhibited greater concentrations of harbor porpoise than other locations in the bay. The relationship between harbor porpoise distribution and prey availability has not been investigated as a reason for the observed trend. Previous research has focused on indicators of food availability for odontocetes, including harbor porpoise, without directly sampling prey. To determine prey availability, I used techniques such as otter trawls, and purse seines to obtain relative abundance of dominant prey items of harbor porpoise. Fine-scale distribution and relative abundance of harbor porpoise was examined concurrently using line transect surveys and correlated with availability of dominant prey items.
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