Science may solve oyster problem

ON THE BAY

Hypothesis: Members of Congress have begun a $50 million campaign that would shift the search for answers from a political to an ecological basis.

March 17, 2000|By Tom Horton | Tom Horton,SUN STAFF

SAVE THE bay? It's time to stop kidding around, and pave the bay -- with oysters, maybe a hundred million dollars worth, just for starters.

A few years ago, investing big bucks in bivalves seemed as likely as building a new buggy whip factory.

Maryland harvests of 1.5 million bushels in the mid-1980s had fallen to 73,000 bushels a year by the mid-1990s -- less than 1 percent of historic levels. Virginia was worse off.

Environmental managers debated "how we could call the bay `restored' without oysters, because it didn't look like they would be part of any comeback," says Mike Hirshfield, science director of the Chesapeake Bay Foundation.

Switch to last week. Key members of Congress and their staffers attended a Chesapeake Bay Foundation reception on Capitol Hill, consuming caviar, crab meat, and nine bushels of plump Chesapeake oysters.

It was to kick off a campaign to appropriate $50 million in federal funds over the next 10 years to achieve a 10-fold boost in Chesapeake oyster stocks.

Maryland has committed $25 million in state money, and Virginia is spending millions to reconstruct oyster reefs like those that broke the bay's surface for miles when the first Europeans arrived.

There are no guarantees, except that such an ambitious restoration will be a long, hard path. Oysters are still near historic low numbers, and still vulnerable to diseases that have plagued them in recent decades.

"There will definitely be years where it looks like we're going backwards," a Virginia scientist predicted at a recent shellfish conference held in Waldorf in Charles County.

Still, there has never been such a likelihood as now of restoring the oysters, whose history has been one of decline since serious harvesting began in the mid-1800s.

Money, support, enthusiasm and -- at long last -- a scientific, rather than political basis for managing oysters, all are converging as never before.

Ideological shift ties ecology to the economy

The current enthusiasm for oysters betokens a profound ideological shift. For the first time in the Bay's history -- and perhaps that of anywhere oysters grow wild -- ecology, not commerce, is driving policy.

It is water quality and rebuilding bottom habitats for an array of marine life that are bringing millions of dollars to bear on oyster restoration.

Boosting seafood harvests and sustaining watermen remain very much compatible goals, but are seen more as a spinoff of returning a healthy, sustainable shellfish community to the bay's heavily tonged and dredged bottom.

A key to placing the oyster in proper context was University of Maryland scientist Roger Newell's calculation in 1987 of the immense capacity of oysters to filter and clarify the bay's polluted waters.

Newell estimated the abundant bay oysters of a century before could have filtered a volume of water equal to the whole Bay every several days, compared to a period of a year or more with the impoverished shellfish stocks of today.

The idea took hold with the public. The Bay Foundation has performed "the oyster trick" for everyone from school kids in its education programs to governors and congressmen:

Take two large jars of murky bay water, one containing a few oysters and one without. After an hour or so, the one with the oysters is clear.

Think of your aquarium at home, another version of the message goes. Destroy 99 percent of its filtration, like we did with oysters. How would the water look then?

A natural, radical approach for returning bay oysters

Another key to seeing the oyster ecologically has been the success in reef building by Jim Wesson of Virginia's Marine Resources Commission.

Wesson, a former waterman with a Ph.D in wildlife management, took the simple, radical approach of returning "to how oysters grew naturally [in reefs]" before intense harvesting broke apart and flattened the hillier, lumpier oyster bottoms of yesterday's bay.

Wesson's experimental reefs are confirming oysters spawn more efficiently when lumped together. They also survive better with all the protected niches provided by the architecture of the reef.

And the reefs, which attract fish and other marine life, soon become what one scientist recently called "incredibly vibrant communities."

A consensus has emerged to construct, during the next ten years, as many as 250 reefs throughout the bay. The idea is to make these sanctuaries, surrounded by harvestable "satellite reefs" that get the fallout of oyster spat from the protected mother reef.

Important questions remain: How big and high off the bottom does a reef need to be? Must it be built entirely of oyster shell, or can cheap alternatives like concrete or dredge spoil be the core, with a veneer of shell?

Depending on the answers, costs of reefs could vary from $380,000 an acre to a tenth of that.

The sanctuary concept -- also being considered as a way to conserve crabs -- underscores the profound shift occurring in oyster management.

Watermen, for example, have always maintained that any oyster bottom not regularly turned over by tongs and dredges quickly becomes unproductive.

To their credit, the Maryland Watermens Association is supporting the ecological approach, while expressing concern for maintaining their fishery. There's no reason they can't benefit, however.

Treating oysters as a "keystone species" critical to the whole bay and to all its fishes and people makes by far the most powerful case for restoration.

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