Surveys of harbor seals in Point Reyes National Seashore last year produced no evidence of mariculture operations disturbing harbor seals in Drakes Estero. According to a National Park Service report released last August and dug up this week by lawyers working on behalf of oyster farmer Kevin Lunny, hikers were the primary source of disturbance. The only specific disturbance mentioned in the report was an instance in which a bald eagle perched on a sandbar, spooking other birds and subsequently, seals.
The survey findings are not surprising. Since 2006, harbor seal monitoring reports have found hikers—as well as kayakers, clam diggers, bobcats and coyotes—cause seals to flush into the water from haul-outs on sandbars. In only one year, 2007, did surveys show disturbances by oyster workers, and Mr. Lunny states that those two surveys conflict with his electronic time clock and payroll records.
In the Environmental Impact Statement on the oyster farm released last month, park scientists called the effects of the farm on harbor seals “long-term, moderate adverse.”
The 33 surveys conducted from last March through July at Drakes Estero indicated the lowest number of disturbances in 12 years. Additionally, harbor seal counts were higher than at any other area along the Marin County coast. The rate of disturbance in Drakes Estero was third after Bolinas Lagoon and Tomales Bay, and declined 28 percent from 2010; disturbance rates also declined at other locations.
Regionally, the 224 surveys conducted last year at Point Reyes National Seashore and Golden Gate National Recreation Area showed a total of 94 disturbances. Twenty-nine percent of these were caused by hikers or other people on foot, and 21 percent were caused by motorboats.