Allen, S. G.
King, M. E.

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Conference Proceedings

Conservation, management, and protection of harbor seats come under the purview of the Marine Mammal Protection Act (MMPA) of 1972 (Public Law 92-522). A primary directive of the MMPA is to protect marine mammal stocks from declining below their optimum sustainable population. To fulfill this directive in California, the California Department of Fish and Game (CDFG), in cooperation with the National Marine Fisheries Service (NMFS), has been conducting annual, state-wide, aerial surveys of harbor seals to assess the status of the population. Harbor seal colonies along the Point Reyes coastline represent about 20% of the estimated breeding population of the state of California, and consequently, have received attention from CDFG and NMFS. In cooperation with these agencies and supported by the Point Reyes National Seashore and the Gulf of the Farallones National Marine Sanctuary, S. Allen has been monitoring harbor seals in Point Reyes since 1982. Audubon Canyon Ranch has supported surveys in Tomales Bay conducted by M. King and volunteers since 1991.

Tomales Bay is one of several locations along the Point Reyes Peninsula where harbor seals (Phoca vitulina richardsi) congregate onshore. Resting areas or "haul-out" sites in Point Reyes are found in remote areas on tidal sand bars, sandy pocket beaches, and offshore tidal ledges or islands (Figure 1). These haul out sites are critical habitat for seals because of their historical, physiological and reproductive significance. They have historical significance because seals congregate at the same site for years, perhaps centuries. Seals benefit physiologically from resting onshore after several hours of continuous diving for food. Seals rest onshore mostly during daylight hours for an average of 7 hr per day and retreat to the water to feed at night. The sites are important for reproduction because seals give birth and nurse their pups on land.

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Allen, S. G., and M. E. King. 1992. Tomales Bay harbor seals: a colony at risk. Pages 33-37 in Wyatt, B, R. Clutter, and L. Sauter, eds. The Third Biennial State of Tomales Bay Conference. Inverness, CA: Inverness Foundation.