Expert Report

Each report is produced by a committee of experts selected by the Academy to address a particular statement of task and is subject to a rigorous, independent peer review; while the reports represent views of the committee, they also are endorsed by the Academy. Learn more on our expert consensus reports.

This report provides a scientific review of a draft Environmental Impact Statement (EIS) from the National Park Service that compares the effects of extending a permit to operate the Drakes Bay Oyster Company shellfish farm in Drakes Estero for the next 10 years, or denying the permit and converting the site from potential wilderness to full wilderness status. The report looks at the Park Service's evaluation of the following resource categories: wetlands, eelgrass, wildlife and wildlife habitat, special-status species, coastal flood zones, soundscapes, water quality, and socioeconomic resources. The report concludes that, because of a limited amount of information on effects of oyster farming in Drakes Estero, the conclusions regarding the impacts projected for seven of the eight of those categories are associated with moderate to high levels of uncertainty, and, for many of those categories, an equally reasonable alternate conclusion of a lower impact intensity could be reached.

The report offered several suggestions for revising the draft Environmental Impact Statement. For example, in several cases, the Park Service defined impact intensity levels in a way that does not clearly correspond to different magnitudes of ecological impact for that resource category. Also, the Park Service could improve the draft by using additional available information to evaluate impacts for some categories, especially soundscapes and water quality: The report suggested the Park Service consider additional mitigation options, for example, the discontinuation of the culture of Manila clams to address concerns about the establishment of this nonnative species.