2019 Harbor Seal Monitoring Complete

Harbor seals hauled out in Point Bonita Cove.

NPS / Kris Liang

August 2019 - The 2019 harbor seal monitoring season has come to a close. Biologists monitor harbor seals at various Marin County locations during the breeding season (March - May) and molt season (June - July). The 2019 breeding season was an average one for the harbor seals. The maximum number of pups recorded during surveys at the main Marin County locations was approximately 1,060, which is very similar to the baseline average of 1,100 pups. Drakes Estero was the most popular pupping site, where biologists recorded 368 pups.

Surveys during the molt season give biologists a good estimate of the total number of seals at the main locations in Marin County where they haul out. This year the maximum number of seals recorded during the molt season was approximately 2,800. That is less than the baseline average of 3,670 seals and follows the past two years of similarly low counts. All sites had a decrease in seals compared to their respective averages, except for Bolinas Lagoon, Duxbury Reef, and Point Bonita. Bolinas Lagoon continues to be a hotspot for harbor seals where biologists have recorded higher than average counts since 2014.

For more information, check out the full 2019 harbor seal seasonal monitoring update, or contact Sarah Codde.

See more from the Bay Area Nature & Science Blog