Millions of commercially cultivated oysters in Drakes Estero may improve water quality and a resident colony of harbor seals may have grown accustomed to eight decades of oyster farming, a federal panel of scientists has concluded.
The scientific report challenges key findings of a National Park Service assessment of the Drakes Bay Oyster Company's impact on the 2,500-acre estuary in the Point Reyes National Seashore in Marin County.
The National Research Council's 53-page report concluded that there is a "moderate to high level of uncertainty" associated with most of the adverse environmental impacts cited in the Park Service assessment.
In two resource categories — water quality and harbor seals — the council's report found a high level of uncertainty, suggesting the oyster farm's impact could be minimal or even beneficial.
The uncertainty level for 13 of 16 categories could mean the impacts of oyster farming were "lower than those presented" in the draft environmental impact study released last year by the Park Service.
Behind the dense scientific studies lies a five-year-old battle over Drakes Bay Oyster Company's commercial toehold on the edge of Drakes Estero, a Pacific Ocean inlet designated by Congress as "potential wilderness" 36 years ago.
Wilderness advocates want the mariculture operation removed, while the company's allies — including some Marin ranchers and officials and California Sen. Dianne Feinstein — support a 10-year extension of the company's permit.
The research council's report, released last week, came as the permit's Nov. 30 expiration date approaches and the Park Service works on a final version of its 500-page environmental report.
Feinstein's legislation in 2009 gave Interior Secretary Ken Salazar sole discretion to renew the permit for the family-operated business that harvests $1.5 million worth of Pacific oysters a year from the estero.
Both sides claimed the research council report — commissioned by the Park Service and drafted by an international panel of 10 scientists — supported their views.
"Basically what's left standing is there are no major (environmental) impacts," said Kevin Lunny, who runs the oyster farm his family purchased in 2005.
Lunny noted the research council's suggestion that 5 million filter-feeding oysters could cleanse 105 million gallons of estero water per day, which the report described as a potentially "beneficial ecosystem service."
"We are thrilled they have come to that conclusion," he said.
Lunny said the report backed his contention that oyster farming doesn't hinder one of California's largest harbor seal colonies. "It's a big deal they (the scientists) are saying it," he said.
Feinstein said the report "offers further proof that the National Park Service is using flawed science to reach a biased, unfair permit decision for the Drakes Bay Oyster Company."
"I once again urge Secretary Salazar to look beyond the flawed science and renew the oyster farm's lease," she said in an e-mail.
Amy Trainer, executive director of the West Marin Environmental Action Committee, said the report found that the Park Service "used the best available science in its review of oyster operation impacts."
Her nonprofit group, based in Point Reyes Station, asserts that oyster farming has no place in a national park.
The research council's conclusions support the Park Service's determination that eliminating the oyster farm is "the environmentally preferable choice for Drakes Estero," Trainer said.