MARIN COUNTY'S NEWS
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SAVE DRAKES ESTERO
By EAC, Sierra Club (WestMarin) and others shown below
"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 Phillip Burton Wilderness Act of 1976 set the stage to preserve Drakes Estero as wilderness for the public to enjoy and wildlife to thrive. The clear intent of the Act is that this critical wildlife resource should be protected as full wilderness once all human obstacles are removed.
Drakes Estero became a designated wilderness-- the only marine wilderness on the west coast from Canada to Mexico -- after a full wilderness review, four years of public meetings, and a lengthy environmental impact analysis. Its designation was supported by the California Resources Agency, Marin County Board of Supervisors and 57 local, regional and national organizations, as well as many individuals. However, due to a pre-1976 lease to Johnson's Oyster Company (JOC), Drakes Estero has not yet reaped the benefits of full wilderness protection. It has been managed by the park service as wilderness with that one exception, which will be corrected in 2012 when the oyster production lease expires.
So it came as a surprise to many when Drakes Bay Oyster Company (DBOC) purchased the lease from JOC in 2005 with full knowledge that the lease expired in 2012 and that the park had legal directives to return the estero to its natural state. DBOC is now campaigning to expand the operation and have the lease extended, threatening the Estero's ecology, the wilderness legislation, and the decades' long effort to preserve it for wildlife and public enjoyment.
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 Drakes Estero's importance to the larger marine ecosystem and clears up some myths, such as the notion that the presence of nine million non-native oysters is better for the ecology of a near pristine estuary than if left to its native state.
Drakes Estero: A Crown Jewel of the Ecosystem
In North America, one third of our waterbird species are in decline; worldwide, 90% of all the fish species have been depleted. More than 60% of our coastal waters are moderately to severely degraded. Despite commendable efforts to conserve land resources, only .01 % of the ocean is effectively protected. Eelgrass beds are critical to ecosystem health and fisheries. Unfortunately, they are found in only a few estuaries in California.
Yet, Drakes Estero's eelgrass beds comprise as much as 7% of the state's total. Blessed with such vegetative richness, Drakes Estero is a linchpin component of the regional ecosystem, a 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 eelgrass for habitat. It is also 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, in the past, reaching a maximum of nearly 2,000 seals during the breeding season. The Drakes Estero colony had been growing significantly from the mid 1990s until a few years ago, largely because the level of oyster operations was reduced during that time.
Myth #1: Oyster Farming has no negative effects upon wildlife.
Disturbance of the larger fauna by commercial oyster farming has been documented at Drakes Estero and elsewhere. Harbor seals have been affected by oyster operations because of direct disturbance to seals resting onshore and displacement by oyster bags where seals rest and nurse their young.
In the past, as many as 300-500 seal pups were born annually in the Estero, 100-200 of which use the middle sandbars. Now that oyster operations have expanded and oyster bags are placed in seal nursery areas, baby seal numbers on the middle sandbars have been reduced to about fifty in 2006 and less than 10 pups so far in 2007.
DBOC's oyster structures directly impair eelgrass habitat by reducing the quantity of light necessary for eelgrass growth. DBOC'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 are capable of "cleaning 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. However, Drakes Estero is open and shallow and the twice-daily tide flushes out the entire estero, so it doesn't carry significant excess phytoplankton or pollutants.
Any "cleaning" that takes place is actually the result of the oysters' devouring organisms that would otherwise be available for native fish, clams and other native species. The losers are the native species that depend upon a healthy, food-filled estuary. Dense racks of non-native oysters feed voraciously on phytoplankton and other nutrients that would otherwise support the natural food chain including the larvae of fish and other invertebrates. One oyster can filter 50 gallons of water per day, so imagine what millions of exotic oysters are doing to reduce food for native species.
Furthermore oyster feces add sediments to the eelgrass beds of the Estero. Researchers from the U.S. Geological Survey identified the feces of oysters - as much as a metric ton per 60 meter square oyster raft - as the primary source of sedimentation, which degrades eelgrass habitat and its ability to support abundant marine life.
Myth #3: The exotic species introduced by commercial oyster operations are safe for the surrounding environment
The introduction of invasive species by commercial oyster operations has been documented for decades in Marin County. Hard structures used to cultivate oysters provide habitat in Drakes Estero that would not otherwise exist, supporting exotic species, such as Batillaria attramentaria, which have been shown to displace natives in Drakes Estero and Tomales Bay. One particularly invasive species found on oyster structures in Drakes Estero is the colonial tunicate (Didemnum spp), an aggressive species that could substantially alter Drakes Estero if it colonized the limited hard surfaces of the estero. In the Atlantic, this species has infested and smothered organisms on a 25,000-acre portion of Georges Bank. There is considerable scientific proof that such exotic infestations are decidedly unsafe for the surrounding environment.
Myth#4: Drakes Bay Oyster Company is continuing a 12,000 yearlong Native American tradition of manipulated oyster farming in Drakes Estero.
Drakes Estero is a small, drowned river valley system that was flooded less than 6,000 years ago. There is no evidence that Native Americans manipulated the aquatic environment to increase oyster numbers in Drakes Estero. There are over 25 Coast Miwok archaeological sites along or near Drakes Estero and virtually all contain shells. But the amount of oyster shells at those sites is small, which makes sense because Drakes Estero contains almost no natural, hard bottomed habitat for oysters. The implication that that DBOC is a continuation of Native American practices is inaccurate.
At present, DBOC is farming as many as 9 million non-native oysters and 1 million clams, far beyond the quantities that exist naturally, which alters the ecology of the Estero. And the techniques used-racks, bags and motorboats-- are much more disruptive than Native American gathering methods.
Agriculture that damages natural systems is not sustainable
We support sustainable agriculture and applaud local farmers and ranchers for working to become better stewards of the environment. We believe that the DBOC's current operations and proposed expansion are unsustainable because the oyster operation already degrades the native ecosystem.
Sustainable models of natural resource use are a very important step in the path towards a more harmonious relationship with the natural world, but we are far from the finish line. While it may not be readily apparent in West Marin, humans still manage the majority of the Earth's natural resources in ecologically destructive ways that are the cause of many of the environmental challenges we face today. Until we learn to manage all of the earth's resources in environmentally sustainable ways, there will always be an important place for protecting biological treasures, such as Drakes Estero, as wilderness. Commercial agriculture uses almost 50% of the lower 48 states while wilderness covers about 2.5%.
Just as we would not cut down the Muir Woods redwoods to plant organic lettuce, neither should we allow this publicly-owned wildlife paradise to be further degraded for the sake of one private commercial enterprise, especially when it's only years away from being protected in perpetuity.
On September 22, 2006, a joint letter was sent to our Congressional representatives by the Sierra Club, National Parks Conservation Association, Marin Audubon Society, EAC of West Marin, Marin Conservation League, Sonoma County Conservation Action, Wilderness Watch, Natural Resources Defense Council, Planning and Conservation League, Ocean Conservancy and others in support of Drakes Estero's continuation to full wilderness protection in 2012.
We therefore oppose any efforts to continue commercial oyster farming beyond the term of the present lease. Drakes Estero is too important as an ecological and recreational resource to compromise it.
For more information, please go to: http://www.nps.gov/pore/parkmgmt/upload/planning_drakesestero_report_061023.pdf
This letter was the collaborative effort by staff and volunteers from the Sierra Club, EAC of West Marin, National Parks Conservation Association, Natural Resource Defense Council and Wilderness Watch staff and volunteers.
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