Saving the Chesapeake
America's largest estuary makes modest gains despite development
When Captain John Smith entered Chesapeake Bay in 1607, he discovered a natural treasure.
The clear water of its rivers darkened with the passing of staggering shad, herring, and sturgeon runs. Flights of ducks filled many square miles of sky, shaking small boats with the force of their sound. Oyster banks rose from the seabed like rugged hills, their summits poking out of the water to form tiny islands.
"Heaven and earth," Smith wrote, "never agreed better to frame a place for man's habitation."
Four centuries later, many still agree. Millions have moved to the region, in part to enjoy the bay's balmy shores and succulent marine life. From the yacht basins of Annapolis, Md., to the fishing fleets of Smith Island, from the crab houses of Baltimore to the bustling ports of southern Virginia, the Chesapeake is central to the lives and identity of the region's towns and cities. Marylanders call it "the land of pleasant living."
But the Chesapeake is in trouble. Where Smith would have looked down to see fish hiding in meadows of sea grass, one can see nothing at all: The water is an opaque brown, flecked with bits of algae and the occasional plastic shopping bag. Nine-tenths of its oysters have vanished, and Virginia recently created an emergency sanctuary to prevent the collapse of the bay's signature blue-crab fishery. Duck, sturgeon, and shad populations are a shadow of their historical levels.
The Chesapeake is not without hope
While other bays and seas around the world have been driven to ecological collapse over the past two decades, the people of the Chesapeake have been working to restore the ecology of the bay. Their experience offers a positive example for many other parts of the world facing similar problems.
Since the early 1980s, Maryland, Virginia, Pennsylvania, and the District of Columbia have been working together to improve sewage and industrial-wastewater treatment in the bay, to protect wetlands, and to improve the health of fisheries. The effort has since grown to enlist numerous federal agencies and tens of thousands of bay residents.
"We've seen some modest improvements in the health of the bay, but much remains to be done," says Michael Hirshfield, vice president of the Chesapeake Bay Foundation in Annapolis. "In the face of continuing population growth, even staying in place has been a serious challenge."
Over the years, state and local governments have enacted laws and spent money to improve the health of the bay. As a result, there's been a resurgence of rockfish, striped bass, and pelicans. But progress is offset by rapid suburban development that suggests a merging of Baltimore and Washington suburbs.
The Chesapeake Bay Foundation releases an annual index on the overall health of the bay, with 100 representing the state of the bay in Captain Smith's time. This year the Chesapeake rated 28, up from 23 just 15 years ago.
At first, people thought the bay would recover if pollution from municipal sewers and factories was reduced, but it's turned out to be more complicated.
"The Chesapeake and its watershed are one large system, and you have to look at problems on that level," says Ann Swanson, executive director of the Chesapeake Bay Commission, a tri-state legislative body. "If you're managing striped bass, you have to look at the juvenile blue crabs that they eat. And if you care about blue crabs, you'd be crazy if you didn't look at the state of sea grasses." And so on.
It's on this ecosystem basis that the three states, the district., and the federal government set new goals this summer for the restoration of the bay.
Like many bays and seas around the world, the Chesapeake has been overwhelmed by the activities of humans along its shores. Fishing, channel dredging, clear-cutting, and industrial pollution all played a role.
But the most severe factor has been nutrient pollution - a deluge of sewage, livestock waste, and fertilizer run-off from cities, suburban homes, and agriculture. The nutrients trigger massive algae blooms and can create huge "dead zones" of oxygen-less water. Fish, crabs, and other organisms must abandon such areas or perish. The algae also snuff out sea grasses - the habitat of blue crabs and other creatures - by blocking out sunlight.
Last year, the Chesapeake gained 4,600 acres of sea grasses, but they remain at about one-tenth of their historical peak of 600,000 acres. The Chesapeake Bay Foundation has been planting stands of the grasses with some success, but cloudy brown water limits recovery.
Most scientists think the bay would be a lot clearer if oyster stocks recovered. Oysters filter algae out of the water. Back in 1607, oysters were so numerous that they filtered the Chesapeake's entire water volume every three to four days. But decades of over-harvesting and, in the late 1980s, the appearance of two parasites - MSX and Dermo - triggered a collapse in oyster populations.
Now, at 1 percent historical levels, the oysters take a year or more to filter the Chesapeake. Fewer oysters mean browner water and, thus, less sea grass and fewer crabs.
Lost oyster banks take varied plant life with them
The disappearance of once-enormous oyster banks also eliminated habitat for many other creatures. Don Meritt, an oyster specialist at the University of Maryland's Horn Point Laboratory in Cambridge, Md., likens the huge vertical banks to coral reefs in tropical latitudes. "Mussels and barnacles, anemones, clams, worms, invertebrates, crabs, fish - the list of species that live on these banks is long," he says. Now, there aren't many of the banks left.
All these factors may help to explain why blue crab populations have fallen by about 70 percent over the past 20 years. As the crabs became scarcer, fishermen have placed more and more traps to try to catch them, says Rom Lipcius, who studies crabs at the College of William and Mary in Williamsburg, Va. "The possibility looms that if we have a hurricane or natural disaster, the stock could completely collapse," he says.
On July 26, Virginia fisheries authorities declared a vast 665-square-mile no-fishing zone through the heart of the lower Chesapeake to protect spawning female blue crabs. The Chesapeake at large is also receiving help. In June, state and federal officials announced a toughened region-wide restoration plan calling for a 30 percent reduction in the sprawl projected for 2012; a ten-fold increase in oysters by 2010; and a commitment to preserve 20 percent of the land in the watershed from development. Surprisingly, the final agreement was stronger than the original draft released to the public for comment months before. Ms. Swanson, who helped draft the plan, says that's because thousands of ordinary citizens wrote demanding tougher action.
"The public didn't wiggle back measures, it bolstered them," she says. "There's a very broad outcry from the people of the region that growth in its current form can't continue because the bay cannot withstand it."
"It gave policy-makers the courage to be stronger leaders," she says.
(c) Copyright 2000. The Christian Science Publishing Society