Attack on wilderness here in the Bay Area

Oyster farm attempts to evade Drakes Estero wilderness deadline

"The great enemy of the truth is very often not the lie - deliberate, contrived, and dishonest - but the myth - persistent, persuasive, and realistic." John F. Kennedy

The Bay Chapter's only federally designated wilderness is at Point Reyes, and a major portion of it is under attack. The threat to Drakes Estero is especially insidious because it is being dressed in the trappings of environmental values.

Drakes Estero is the only designated marine wilderness on the West Coast from Canada to Mexico. The Phillip Burton Wilderness Act of 1976 set Drakes on the course to become wilderness, but with a delay: it could not formally become wilderness until 2012, when a pre-existing lease to an oyster producer would expire. With that one exception, it has since 1976 been managed by the National Park Service as wilderness.

It came as a surprise to many in 2005 when Drakes Bay Oyster Company purchased the lease from Johnson's Oyster Company. Drakes Oyster knew about the scheduled expiration of the lease, but is now campaigning to expand the operation and have the lease extended. Such operations would threaten the Estero's ecology, the wilderness legislation, and the decades-long effort to preserve the Estero.

Unfortunately, significant misinformation has been distributed about the effects of large-scale oyster operations on Drakes Estero. We hope that this article helps to inform you about the Estero's importance to the larger marine ecosystem and clears up some myths, such as the notion that nine million non-native oysters could be better for the ecology of a near-pristine estuary than leaving it to its native state.

Drakes Estero: a crown-jewel ecosystem

Drakes Estero's contains 7% of the state's eelgrass beds. The Estero is a key resource for many animals, including Dungeness crab, lingcod, rockfish, English sole, steelhead, waterbirds, and seals. Many of the approximately 60 fish species that use the Estero depend on its plankton for food and on its eelgrass for habitat. It is a seasonal home for threatened bird populations, including thousands of federally listed brown pelicans, and black brant geese, an Audubon watch-list species.

The harbor-seal population in Drakes Estero is one of the largest concentrations in California. At one time it would reach nearly 2,000 seals during the breeding season. The colony was growing significantly from the mid-1990s until a few years ago, largely because the level of oyster operations was being reduced.

Myth #1: oyster farming is fine for wildlife

Disturbance of native fauna by commercial oyster farming has been documented at Drakes Estero and elsewhere. Harbor seals are disturbed while resting onshore and displaced by oyster bags from resting and nursing places.

As many as 300 - 500 seal pups used top be born annually in the Estero, 100 - 200 using the middle sandbars. Expanded oyster operations and oyster bags placed in seal nursery areas have reduced baby seals on the middle sandbars to about 50 in 2006 and less than 10 so far in 2007.

The Drakes Bay oyster structures directly impair eelgrass habitat by blocking the light necessary for eelgrass growth. The operation's motorboat propellers also chop up eelgrass foliage. A study of oyster operations in Tomales Bay showed that oyster racks reduced shorebird use of tidal flats as well.

Myth #2: non-native oysters can "clean up" their environment

As filter feeders, oysters and clams are known for their ability to improve water quality by removing excess phytoplankton and harmful pollutants. Drakes Estero, however, is flushed twice daily by tides, so that it doesn't carry significant excess phytoplankton or pollutants.

Any "cleaning" that takes place is actually the oysters' devouring of organisms that would otherwise be available for native fish, clams, and other native species. Dense racks of non-native oysters unnaturally supported in the water column greatly increase filtering capacity. One oyster can filter 50 gallons of water per day. In Drakes Estero millions of exotic oysters feed voraciously on phytoplankton and other nutrients that would otherwise support the natural food chain. The oysters consume the larvae of fish and other invertebrates. Researchers from the U.S. Geological Survey (USGS) found that there are so many oysters in the Estero that they deplete nutrients and larvae from nearby ocean areas. These areas include Marine Protected Areas that are intended to provide safe areas for larval development to help depleted populations recover.

Oyster feces add sediments to the eelgrass beds. The USGS identified oyster feces as much as a metric tonne per 60-meter-square oyster raft as a primary source of sedimentation degrading eelgrass habitat and its ability to support abundant life.

Myth #3: a 12,000-year Native American tradition of manipulated oyster farming

The small drowned river-valley system of Drakes Estero was flooded less than 6,000 years ago. There is no evidence that Native Americans manipulated the aquatic environment to increase native oyster numbers. Modern racks, bags, and motorboats are much more disruptive than Native American gathering methods.

The more than 25 Coast Miwok archaeological sites along or near Drakes Estero contain shells but few oysters. This makes sense, because of the lack of hard-bottomed habitat for oysters.

The implication that current oyster-raising is a continuation of Native American practices is inaccurate. Local Coast Miwok have written a letter to the Point Reyes National Seashore supporting the Estero's return to wilderness.

Myth #4: Drakes Bay Oyster Company practices sustainable agriculture

The Sierra Club supports sustainable agriculture and applauds local farmers and ranchers for working to become better stewards of the environment. The current operations in Drakes Estero, however, even without expansion, already degrade the native ecosystem, and are unsustainable.

Just as we would not cut down the Muir Woods redwoods to plant organic lettuce, neither should we allow the publicly owned wildlife paradise of Drakes Estero to be further degraded for the sake of one private commercial enterprise. In another location, oyster-farming might be sustainable and appropriate, but not here.

On Sep. 22, a joint letter was sent to our congressional representatives by the Sierra Club, National Parks Conservation Association, Marin Audubon Society, Environmental Action Committee of West Marin, Marin Conservation League, Sonoma County Conservation Action, Wilderness Watch, Natural Resources Defense Council, Planning and Conservation League, Ocean Conservancy, and others to support the progression of Drakes Estero's to full wilderness protection in 2012.

Drakes Estero is too important as an ecological and recreational resource to compromise it.

For more information, please read www.nps.gov/pore/parkmgmt/upload/planning_drakesEstero_report_061023.pdf

Gordon Bennett, chair, Sierra Club Marin Group