Some Maryland watermen are dumping thousands of old tires in the Chesapeake Bay, and getting paid by the state to do it.
No, it's not a sinister scheme to hide the mountains of used rubber littering the land.
The state Department of Natural Resources wants to see if it can help restore the bay's depleted oyster populations, using cast-off tires to replace some of the thousands of acres of natural oyster reefs destroyed over the past century and a half.
In the process, officials also hope to find a use for some of the 4 million-plus steel-belted radials and bias-ply tires discarded every year by motorists in Maryland.
So the state has enlisted watermen in a pilot project to create artificial reefs. Tires, bound together in threes and weighted with concrete, are being dropped overboard from skipjacks and other watermen's boats.
About 900 tires collected at Easton's landfill by the Maryland Environmental Service, a branch of DNR, are being deposited on a 2-acre patch of bay bottom just west of Tilghman Island.
Another 30,000 tires will be sprinkled over a 50-acre site nearby this summer.
In the next two years, state officials say they plan to cover another 2,000 acres of bay bottom with tire reefs, possibly putting them off Calvert Cliffs, at the mouth of the Patapsco River and in the Severn, among other places.
"The theory is, if we rebuild the bottom, we'll rebuild oyster populations," said W. P. "Pete" Jensen, state fisheries director.
Oyster harvests in the bay have hit all-time lows in recent years, which watermen attribute to parasitic oyster diseases. But overfishing and the loss of underwater reefs on which oysters can grow have been largely responsible for their long-term decline, scientists say.
More than half the 280,000 acres of natural oyster bars identified by state surveys 80 years ago have been lost, according to a study by the University of Maryland's Chesapeake Biological Laboratory in Solomons.
Reefs were physically chewed up over the years by watermen as they dredged and tonged for their harvests, the study says.
The old bars have either disappeared altogether, or have been worn down to where they no longer protect shellfish from being smothered by silt and mud settling on the bottom.
Tire reefs are intended to provide homes for oysters, mussels, barnacles and a host of worms, tiny crustaceans and other marine life that normally populate hard outcroppings from the bay bottom.
But watermen, scientists and environmentalists have mixed feelings about the experiment. Some wonder whether toxic metals and chemicals might leach out of the tires into the water, while others worry that the public may get the wrong idea from this project.
"You're making a landfill out of the bay, that's what you're doing," complained Fred Pomeroy, a waterman in Cambridge. "They'll be dumping refrigerators in the bay next."
Officials say such fears are unfounded, but they intend to proceed cautiously the first few years until the safety and effectiveness of the tire reefs have been proved.
Tires have been used to create artificial fishing reefs for years here and elsewhere, and studies have shown that young oysters will attach themselves to tires.
One eight-tire reef dropped in Eastern Bay south of Kent Island in the late 1960s was pulled up from the bottom recently and found to be covered with 102 oysters, according to John Foster, a DNR fisheries biologist.
While bay scientists welcome the state's efforts to rebuild oyster reefs, some question the use of tires. Studies have shown that young oysters attach best to natural shells, said Victor Kennedy, a marine biologist at the University of Maryland's Horn Point Environmental Laboratory near Cambridge.
The state has been dredging old shells from the bay bottom in more recent years to rebuild oyster bars that are worked by watermen, but the dredging is increasingly costly and difficult, said Mr. Jensen. The state has experimented with making reefs from a variety of other materials, including construction rubble, concrete and fiberglass. But tires seem the most promising, given their abundance.
There are an estimated 10 million used tires sitting in stockpiles and dumps all over the state, where they pose health, fire and environmental hazards, according to Michael Sullivan of the Department of the Environment. The state recently began charging $1 on every new tire sold to finance tire disposal and recycling efforts, and funds from that tax are being used in the oyster reef project.
This year's tire reef creation is expected to cost about $100,000, according to Mr. Jensen. The state also has received $200,000 from the Environmental Protection Agency for artificial reef construction.
Tire reefs are being created for ecological reasons, officials note, rather than to rebuild Maryland's anemic oyster industry. Oysters can help maintain the bay's water quality, since they feed on the nutrients that are over-enriching the bay.