Coastal Post Online


May, 2004

Farallones Marine Sanctuary Volunteers Halt Harbor Seal Pup Mortality

San Francisco-April 19, 2004. For Earth Day 2004, Gulf of the Farallones National Marine Sanctuary celebrates a significant victory for the Bay Area's harbor seal population. After seven years of determined effort, it has successfully reversed a steady decline in harbor seal pupping linked to disturbances at the sanctuary's two largest seal rookeries, Bolinas Lagoon and Tomales Bay.

The Farallones sanctuary recruited "citizen scientists" as volunteers for its Sanctuary Education, Awareness and Longterm Stewardship (SEALS) program. Under the direction of sanctuary biologists, SEALS volunteers monitored harbor seals and their pups on their rookeries and documented disturbances by birders, clammers, and other visitors to these sensitive habitats. Volunteers deployed bright flags on mudflats to create buffers around haulouts to warn clammers and others of their proximity to the seals. Armed with telescopes and a wealth of knowledge about harbor seal natural history, volunteers interacted with visitors and invited noninvasive observation of these shy marine mammals. Their efforts were rewarded when pup mortality from disturbance dropped sharply.

This spring the program shifts focus away from research, putting greater emphasis on outreach and enforcement. Information on seal populations and impacts of disturbances will be released in a report later this year. Sanctuary Manager Maria Brown noted, "These volunteers are true coastal stewards. They have helped the sanctuary to balance the needs of its wildlife with the needs of the public."

Gulf of the Farallones National Marine Sanctuary is home to one-fifth of the California population of harbor seals. In Spring harbor seals haul out on beaches and sandbars to give birth. Spring also marks open season for clammers at Tomales Bay, and more visitors to the coast in general. The proximity of seal birthing sites to San Francisco's urban population of nearly 8 million increases the likelihood of disturbance by humans, dogs, motor boats, kayaks, and aircraft. Disruption can result in seal pups being separated from their mothers and the ensuing death of the pup. Repeated disturbance can cause seals to abandon rookeries altogether.

For information on sanctuary programs and issues, visit the sanctuary's and Farallones Marine Sanctuary Association's websites at and, or call 415/ 561-6622.



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