Commission finds data “stretched”


For the second time, a national scientific report has found no conclusive negative impact from Drakes Bay Oyster Company on harbor seals inhabiting the coastal inlet in which it operates in Point Reyes National Seashore.

The report, conducted by the Marine Mammal Commission and a panel of independent experts, assessed years of data, including analyses by National Park Service scientists that the report states relied on data that are “scant and have been stretched to their limit.” It made no recommendation on whether to close the farm or allow it to operate past next year—when its 40-year use permit expires—instead endorsing further research, and, should the operation continue, adaptive management.

Environmentalists and oyster farm supporters both claimed vindication from the report’s findings. Amy Trainer of the Environmental Action Committee and Gordon Bennett of Save Our Seashore wrote in a mass email that the report affirmed charges that the farm “may negatively impact harbor seals and the federal protections intended for them.” Drakes Bay Owner Kevin Lunny said the report undermines the Park Service’s pending Environmental Impact Statement (EIS), which alleges long-term harm to harbor seals should the farm receive a lease extension.

The commission has been collecting and analyzing information on the farm since 2009, when it was solicited by local environmentalists angered by a National Academy of Sciences report that found inconclusive evidence that the farm negatively impacts harbor seals. A panel of marine scientists was assembled in Point Reyes in February, 2010 to make individual reviews. Their reports are included in an appendix to the report.

Originally, the panel intended to review all potential sources of disturbance to harbor seals in Drakes Estero, including wildlife, park visitors—particularly hikers and kayakers—and overhead air traffic. Those were abandoned, the report states, because it was clear that “the primary question, strongly contended, is whether mariculture has affected or is affecting the seals.”

Lunny expressed concerned that exclusively addressing mariculture disturbances leaves anyone reading the report with the indelible impression that removing the oyster operation will remove all potential disturbances to the seals.

The report also examined the 281,000 hidden-camera photographs that were taken by Park Service volunteers between 2007 and 2010, finding no conclusive results from their content. Because each scientist’s report was submitted prior to their revelation, none of them incorporate or discuss them. Lunny believed that “had those scientists had access to those photos it could have seriously changed the results of their reports.”

Nevertheless, many of the scientists found little evidence that the farm was harming or would harm seals. Steven Jeffries of the Washington Department of Fish and Wildlife explained that seals often habituate to regular human activity, such as oyster boats, if they perceived it as benign. “I would therefore conclude that there is really no reason why oyster farming and harbor seals cannot coexist in a healthy and productive Drake’s Estero ecosystem,” he wrote.

In examining the Park Service’s analyses, the commission found that only the most recent study—known as Becker 2011—provided some indication that oystering and seal activity were directly correlated. “However,” it said, “the data and analyses are not sufficient to demonstrate a causal relationship.”

It also formally dispelled a 2007 claim that the mariculture operation had caused an 80 percent decline in seal mothers and pups at one haul-out site in the estero that year, claiming that the assertion was based on an inappropriate comparison to data from 2004, when seal counts were unusually high.

Officials at Point Reyes National Seashore announced last week that they would extend the public comment period on its draft EIS through December 9 in light of the report’s release. Spokeswoman Melanie Gunn did not respond to requests for comment on how the Seashore plans to manage new comments that cite information from the report, or whether the new information would warrant initiating a supplemental EIS, with its own draft and public comment period.