By Mark Prado,
Marin Independent Journal
Thursday, July 21, 2005
Marin's Rod and Gun Club is the latest spot in Marin where scientists are hoping to see a renaissance of a tiny oyster that could make the bay a cleaner and healthier place.
Volunteers spent several days last week in the muddy flats off the Rod and Gun Club placing pallets full of shells on which Olympia oysters could grow. It is among the first of what scientists hope are several attempts to bring back the native oysters - efforts that have so far been focused on Marin.
"Marin has been a focal point because there are some very accessible sites," said Natalie Cosentino-Manning, restoration specialist with the National Oceanic and Atmospheric Administration, which is monitoring the work. "But we want to see this happen all over the bay."
The Olympia oyster, which measures no more than 1 1Ú2 inches in diameter, once was plentiful in the bay, acting as a water purifier, as well as habitat and food for a variety of fish species.
When settlers arrived during the Gold Rush, the oysters became a food source for a burgeoning population and were just about harvested out of existence.
Small pockets of the mollusks - the only native Bay Area oyster - remain, but nowhere near the population of a century ago. The oysters are marked by irregularly shaped, fluted shells ranging from chalky-white to purplish-black in color. They are more abundant in Washington state, where the mini-mollusk derives its name.
Last year in Tiburon, pallets with bags of empty oyster shells stacked into the shape of a pyramid were dropped into water at 12 spots in Richardson Bay - including near Blackie's Pasture and Tiburon Audubon Center - and scientists report the oysters are appearing.
When oyster larvae are released, they need to settle on shells' hard surfaces to grow.
After the work in Tiburon, the Rod and Gun Club applied for and received a $50,000 grant from Fish America, through NOAA, to do similar work.
"People don't think of the Rod and Gun club as a conservation-minded group, but it is," said Bud Abbot, a club member and marine biologist who will collect data from the project. "The work in Richardson Bay went well and now we are trying the same in San Pablo Bay."
The work done off the Rod and Gun Club's pier is similar to what occurred in Tiburon, with eight pallets being dropped in various locales to allow oysters to grow. In this case, however, the pallets are suspended by stakes keeping them off the bay's floor, Abbot said.
Biologists had been concerned the non-native drill snail would get into the oysters and eat their way through the shells, but so far that hasn't been a problem.
The project is also likely to provide fishing opportunities off the pier, with researchers expecting a "halo effect" of fish congregating near the pallets as they seek shelter and food.
The pier has also added another dimension to the oyster project.
"By using the pier that extends into the bay we could put the pallets at different depths," said Todd Meyer, a director on the Rod and Gun Club board. "We can see at what depth the oysters grow best and be able to duplicate that in other areas."