1997 Harbor Seal Pupping Season at Point Reyes National Seashore
Contact: John Dell’Osso, 415-464-5135
Point Reyes National Seashore has the largest breeding colony of harbor seals in California. Resting and pupping harbor seals come onshore in various parts of the park particularly in Tomales Bay, Tomales Point, Double Point, and Drakes Estero. Several hundred seals congregate within the Estero and numerous seals assemble near the mouth of Tomales Bay on tidal sand bars off Dillon Beach. Drakes Estero is one of the largest mainland pupping sites in California.
From March 15 through June 30, an annual closure of Drakes Estero is implemented to protect the harbor seals during this most sensitive time of year. The closure applies mainly for kayak and canoe usage but is applicable to hikers, surfers, windsurfers, and other water sport users around harbor seal colonies in the area. The National Park Service asks park visitors to avoid disturbing seals in these areas to ensure a successful pupping season. Research has demonstrated that harbor seal populations rapidly decline when disturbed during the breeding season.
Point Reyes National Seashore recently received the title of ownership of Hog and Duck Islands as a donation from Audubon Canyon Ranch. The National Seashore has agreed to manage the islands to maximize environmental values and continue the exceptional resource stewardship which Audubon Canyon Ranch accomplished over the years.
The east side of Hog Island in Tomales Bay is also terrestrial resting site for harbor seals and seabirds' year round. Harbor seals haul out on the sand bar at Hog Island throughout the year but are most abundant there during the winter when their preferred prey, Pacific herring, spawn in Tomales Bay. Up to 250 harbor seals were counted on Hog Island in the early 1980s but because of frequent disturbance by boaters and people visiting the island, the number of seals has dwindled to around 30. During the spring months, females with pups may also haul out there. To ensure that harbor seals are not disturbed, visitors are asked to stay at least 100 yards (300 feet) away from resting seals.
A few species of seabirds rest on Hog Island including brown pelicans, which occur in Tomales Bay during the summer and fall months of the year. They forage on various species of small schooling fish that congregate in Tomales Bay.
Both harbor seals and brown pelicans are protected and therefore, it is unlawful to disturb them while they are resting onshore. Harbor seals are protected under the Marine Mammal Protection Act of 1972, and brown pelicans are listed as federally-endangered species.