Bay holds lessons within a shell

ON THE BAY

Oyster: The gray mollusk, once plentiful on our shores but harmed by human actions, has much to teach our society.

January 15, 1999|By Tom Horton | Tom Horton,SUN STAFF

HAVING DILIGENTLY overwhelmed our landscapes for decades with bedroom suburbs, strip malls and mega-stores, we are searching, with programs such as Smart Growth, for ways back to real, human-scale villages and urban neighborhoods.

Environmentally, socially and economically, such places work better than sprawl. More perhaps, they promise a rootedness, a sense of community, for which most of us seem naturally to yearn.

There are intriguing and underappreciated analogies to this in the Chesapeake Bay, beginning with one of its humblest creatures: the good, gray oyster.

For thousands of years, Chesapeake oysters grew -- like oysters around the world -- in reefs. Young ones attached to old ones and to the shells of dead ones, extending outward and upward so that their accumulation sometimes broke the surface of the water on low tides.

Early European visitors frequently remarked on such phenomena as hazards to navigation. In rivers such as Virginia's James, the names of long-gone oyster reefs remain on navigation charts.

The reefs were more than agglomerations of oysters and shells. They were rich, diverse, concentrated communities, covered with sponges and the shells of other mollusks, offering millions of nooks and crannies in which juvenile fish, little crabs and young oyster "spats" could take refuge from predators.

As for larger fish, it is almost dogma among modern anglers that where one finds underwater "structure," whether dead trees or stone piles or old shipwrecks, one finds good fishing.

Artificial reefs are a preferred tool of fisheries managers worldwide. One can only imagine the fish habitat that the bay bottom offered when hundreds of thousands of acres were studded with mature oyster reefs.

Demolition of the natural reefs began 150 years ago, as large sail and steam craft began busting apart the bay bottom with heavy iron oyster dredges.

At the time, apart from concerns about the extent of the harvesting (which was rapacious), leveling and spreading the reefs was seen as a good thing.

It dramatically increased the acreage covered by oysters and made them more accessible to both dredging and tonging. It played into our cultural concept -- still powerful -- that "working" the land (or bay bottom) conferred ownership and implied an almost sacred duty to make nature fruitful.

Busting up the reefs also allowed oysters, freed from growing in such close quarters, to assume a very different shape -- fuller and fatter, instead of long and skinny. The change was similar to the difference in a tree's growth when it is in a spacious park, as opposed to fighting for space and light in a dense forest.

All to the good, it might have seemed. But scientists are beginning to recognize that the present shape of the oyster population, horizontal and spread out, simply might not work as well as the old reefs.

Today's oysters are more vulnerable to being covered by sediment and probably are not able to reproduce as efficiently. Neither do they provide as good a habitat for other species as the reefs did.

It might seem late in the game to worry about such things. Oysters are estimated at only a few percent (or less) of their historic bay populations.

The very structure of the bay bottom, its natural shellfish reefs, has been dramatically altered. If we had transformed Western Maryland's landscape to resemble the Eastern Shore, it would have occupied whole books. But beneath the bay, a major transformation passes almost without remark.

Late in the game or no, one of the more compelling presentations I have heard was made last week, when Maryland and Virginia shellfish experts provided an update on oyster recovery programs to the Chesapeake Bay Commission, a body of legislators from three states.

Much of the talk was about reefs. James Wesson, a Virginia oyster specialist who spoke to the commission, has been building reefs for five years, using old oyster shells, capped with live oysters.

Working in several rivers, from fairly clean waters to the badly polluted Elizabeth at Norfolk, Wesson is seeing strikingly higher survival and spawning in his reefs than in adjacent shellfish waters -- also teeming fish populations in and around them.

The reefs appear to be spreading their wealth, too. One reef, where Wesson put 2,000 bushels of oysters, had such a good spawn that he was later able to take up and move 50,000 bushels of "seed" -- shell or live oysters on which young spat attach -- from waters in the vicinity of the reef.

"Nature is working much faster than anyone would have guessed," Wesson said, adding, "Reefs are, after all, how this creature [the oyster] evolved."

Maryland is pursuing a more ambitious oyster-restoration program than Virginia but has moved more timidly with reef experiments.

Ironically, an expanded reef program is opposed in both states by watermen, who fear the precedent of such sanctuaries, which are off-limits to harvest.

That is incredibly shortsighted. There is no reason we -- and the bay's water quality -- could not benefit from a vast system of sanctuary reefs, fueling higher oyster production throughout the area, including places watermen would continue to harvest.

Restoring any significant portion of the natural, reef-like bay bottom will be a huge and long-term job. A modest reef of 100,000 square feet might cost $100,000.

It is ultimately a job that goes beyond oysters, including restoration of sea grasses to a half-million or more acres of bay bottom. Like oysters, grasses provided habitat and clarified the water.

The bay was once more rooted in these shelly, hilly, grassy, nurturing bottom communities, now supplanted by a polluting soup of free-floating algae.

Restoring community to both watershed lands and the bay bottom is what our efforts should be about as we approach the next century.

Pub Date: 1/15/99

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