June 2004

San Jose Mercury News
In restoring oysters, scientists see hope for new life in bay
BIOLOGISTS ATTEMPT TO TURN BACK CLOCK IN REBUILDING REEFS
Tuesday, June 8, 2004
By Paul Rogers

TIBURON - Standing precariously in a 17-foot Boston Whaler bobbing in San Francisco Bay on a recent weekday morning, Mike McGowan and two assistants heaved six large mesh bags, all tied to a heavy wooden pallet, over the side.

They watched, satisfied, as the mass splashed and then sank, bubbling under the dark blue waters.

Illegal trash dumpers? Mafia hit men?

Neither. McGowan, a marine biologist, is attempting to turn back the clock 150 years in San Francisco Bay by restoring its native oysters. From the 1850s to the 1920s, oysters were a cornerstone of the bay's economy and ecology, the most lucrative fishery in California and the stuff of Jack London stories. Yet today, they teeter near extinction, mostly forgotten.

Two inches long, with a purplish-black shell and meat the size of a silver dollar, the bay's native shellfish is the Olympia oyster, a humble mollusk known to scientists as Ostreola conchaphila.

Mirroring efforts already under way in Chesapeake Bay, McGowan is attempting to prove that it is possible to rebuild oyster reefs in San Francisco Bay -- gradually replacing the vast reefs of the 1800s that were smothered by gold miners' silt, poisoned by raw sewage and carved up by Barbary Coast oystermen.

His experiment involves placing large bags of oyster shells in Richardson Bay, near the Tiburon shoreline, in Marin County.

Today, only tiny pockets of native oysters remain off Redwood City, Emeryville and a few other locations. They produce larvae, each the size of a grain of sand, that drift around the bay. Because there are almost no oyster shells for them to latch onto and grow into full-size oysters, most of the larvae die or are eaten by fish.

``They're scattered, and are just barely hanging on,'' McGowan said. ``It's like all these little light bulbs winking on and off all around the bay.''

Restoration help

Once oysters find McGowan's artificial reefs, he expects them to latch on and start growing. They then will produce their own shells and expand in number. ``Once they get started, they create their own reefs,'' he said.

Most important, if oysters ever could be restored in large numbers to San Francisco Bay, the ripple effect would be enormous, scientists say. Filter feeders who eat plankton, oysters literally clean the waters they live in by filtering as many as 25 gallons of water each a day. The reefs they build provide shelter for fish, worms, sponges, crabs and other aquatic life, and their meat offers food for ducks, bat rays and starfish.

Perhaps most intriguing, studies in Chesapeake Bay and the Gulf of Mexico have shown that when healthy oyster reefs improve water quality, underwater beds of eelgrass flourish, providing more places for herring and other fish to spawn.

``People keep asking me, `When is the big oyster feed?' '' joked McGowan, a senior research scientist at San Francisco State University. ``But there isn't going to be one. We're trying to improve habitat and make the bay cleaner.''

McGowan's work is funded mostly by a $30,000 grant from the National Oceanic and Atmospheric Administration Fisheries Restoration Center.

``People driving across the bridges see a beautiful body of water, and they have no idea what is happening underneath,'' said Natalie Cosentino-Manning, a marine biologist with NOAA in Santa Rosa. ``We have a native species here, and if we help it along, it will be not only good for oysters but also good for us. It is hopeful.''

Because the bay lost nearly all of its oyster reefs, today its eelgrass struggles, and instead of a mix of rocky outcroppings, its underwater profile is mostly sand and mud.

``We hope to see a chain reaction,'' Cosentino-Manning said, ``birds taking advantage of the new habitat, fish taking advantage of the new habitat.''

McGowan is assisted by 28 volunteers from the Tiburon Audubon Center. They help with record-keeping and loading and tying together the bags of oyster shells -- purchased from commercial growers in Washington and Oregon. Last week, the crews finished setting up the experiment by placing 12 pallets, each with six 40-pound mesh bags full of oyster shells, in about five feet of water in Richardson Bay.

They will return to check on them monthly.

Small steps

``Restoring the bay sounds so daunting,'' said Michele Pearson, executive director of the Tiburon Audubon Center. ``But this shows there is something we can do, even if it is just a small thing.''

Similar efforts are under way at Tomales Bay in Marin County, and in Chesapeake Bay, where a decade of building shell reefs has doubled the oyster harvest.

Four years ago, McGowan and volunteers from Save the Bay put out ``oyster shell necklaces'' in five locations around the bay. After a couple of months, the ropes, with shells hanging on them, were covered with oysters at Richardson Bay, Sausal Creek near Oakland and Coyote Point near Burlingame. That proved the tiny floating larvae would prosper if there were enough shells in the bay.

``It's hard to feel connected to what is living on the bottom of the bay,'' said Marilyn Latta, habitat restoration manager at Save the Bay, in Oakland. ``But marsh hawks, egrets, harbor seals -- all kinds of species -- are dependent on what is living in the mud and the rocks.''

Although most Bay Area residents may not realize it, oysters were a vital part of the bay's history.

Oysters were once so abundant that their jagged shells produced a ``white glistening beach that extends from San Mateo for a dozen or more miles southward,'' according to one 1893 writer.

Oysters were a staple food for Ohlone Indians. They left mounds of oyster and mussel shells, known as middens, along San Francisco Bay and its creeks.

During the Gold Rush, miners paid $20 a plate for San Francisco Bay oysters. An industry sprang up, and in 1853, Capt. John Stillwell Morgan began importing oysters from Willapa Bay, Wash., to San Francisco Bay because they were larger.

Known as ``sea fruit,'' oysters were grown in beds off Sausalito. But hydraulic mining in the Sierra Nevada sent more than 1 billion tons of silt and mud into the bay from 1852 to 1884, smothering many of the beds in mud up to three feet deep.

Morgan established new oyster beds off Millbrae, where there was less silt, and began buying up underwater land and competitors' companies off Santa Clara and Alameda counties.

Native oysters in the bay became depleted from overfishing and poisoned by sewage. Using the new transcontinental railroad, Morgan brought tens of thousands of tiny oysters -- each the size of a dime -- every year from New York waters, packed in ice in wooden barrels, to the bay. He owned a monopoly from Alaska to Mexico. Every year, hundreds of men in shallow-bottom boats with giant forks known as tongs harvested the bounty, which reached more than 1 million pounds a year.

Center of industry

``By the 1890s, all the oysters that were consumed on the Pacific Coast of North America came from San Mateo County,'' said Mitch Postel, president of the San Mateo County History Museum.

``It was like Silicon Valley. The Bay Area was known for oysters all across the West.''

Celebrated author Jack London, as a 15-year-old boy, joined roving gangs on the Oakland wharves known as oyster pirates. The crews stole oysters from the South Bay and Peninsula during the dead of night. London eventually switched sides, joining police who worked to apprehend the thieves. His exploits are recounted in his 1905 short story ``A Raid on the Oyster Pirates.''

The oyster industry began to die out around World War I, when pollution choked oxygen from the water. The catch shrank. Oysters were blamed on several typhoid outbreaks. And the industry moved to cleaner waters, like Tomales Bay in Marin County, where it continues today. The Morgan oyster company sold most of its holdings in 1923 to Pacific Portland Cement Company, later Ideal Cement, which dredged massive oyster shell reefs, some 30 feet deep, to make cement at its Redwood City plant, which closed in 1971.

For McGowan to spread oysters en masse would require the success of his experiment, and then permits from government agencies and funding to create more artificial reefs. That could be problematic in places because the reefs could block some boating routes, and could be considered ugly at low tide by owners of waterfront homes.

Some longtime bay advocates hold out hope, however.

As a biologist for the state Department of Fish and Game in 1960, Bill Kier was asked at a conference on water pollution what the goal should be for San Francisco Bay. A productive oyster fishery, he said.

``Everybody thought that was the funniest thing they had ever heard,'' Kier said.

But now that the bay's water has been cleaned considerably by a generation of tough pollution laws, and with McGowan hard at work, Kier has hope.

``I'm now 68 years old, and I'm determined to live long enough to eat shellfish from San Francisco Bay,'' he said.

OLYMPIA OYSTER

An effort to restore oysters to San Francisco Bay could have an enormous ripple effect, scientists say. Once established, oysters are capable of:

Filtering 5-25 gallons of water each per day

Building reefs that provide shelter for many aquatic animals

Expanding underwater beds of eelgrass, habitat for many kinds of fish