The bay bounds back Growth: Life-giving underwater grasses have expanded by more than 6,000 acres, a survey shows.

June 03, 1998|By Heather Dewar | Heather Dewar,SUN STAFF

The news was good, and the scientists and policy makers gathered on the banks of the South River yesterday were half-giddy: The Chesapeake Bay's life-giving underwater grasses grew abundantly last year. Dead zones with no oxygen shrank slightly. And the bay's main pollutant, nitrogen, was as low on average as it has been in more than a decade.

"This is where we see the fruition of 15 years' worth of hard work," said Robert Magnien, a scientist with the Maryland Department of Natural Resources, wearing a necktie and waders, knee-deep in jade-green river water to announce researchers' findings for 1997. "The people of Maryland have struggled so long to reduce [pollution] in Chesapeake Bay. One obvious message is, it works."

The Chesapeake's 13 varieties of underwater grasses expanded their reach by almost 6,000 acres between 1996 and 1997, an increase of almost 9 percent, according to an annual survey by Virginia Institute of Marine Sciences researcher Robert Orth. That's a significant gain in shelter for young fish and crabs, food for waterfowl, erosion protection for people, and other natural benefits the grasses provide.

About 69,000 acres of underwater meadows grow on the bay bottom -- almost twice the area as in 1984, when the grasses reached their nadir, and more than halfway to the region's official restoration goal of 114,000 acres.

But it's not clear whether most of the credit for 1997's apparent rebound belongs to humankind or to Mother Nature, which sent the region a relatively dry year, reducing the flow of pollutants from land to water. Though scientists found slightly less oxygen-starved water along the bay bottom and lower levels of nitrogen, which fuels algae blooms, "it will be a few years before we know if those improvements are part of a trend or are just due to the drought and low flow," said a Chesapeake Bay Program scientist, Carlton Haywood, in a report released yesterday. And there's a dark spot amid the bright news. For the fifth straight year, bay grasses declined in Tangier Sound, where the underwater meadows provide vital shelter to young blue crabs.

Shrinkage

In 1992, grasses covered more than 18,000 acres of bottom in the sound and around the islands that form its western edge. By 1997, those grassy areas had shrunk by nearly half, to about 9,400 acres.

The Tangier Sound losses are ominous because the area's underwater grasses provide early-season shelter for young blue crabs, croakers, and other bay creatures making their annual spring migration from the sea.

Bill Matuszeski, director of the Environmental Protection Agency's Chesapeake Bay Program, said the decline in Tangier grasses fits with other signs -- like last summer's outbreak of toxic Pfiesteria piscicida -- showing that the Lower Eastern Shore is not recovering as well as the rest of the bay.

"The story is actually pretty consistent," Matuszeski said. "Pfiesteria happened in a part of the bay where we're continuing to see losses, and where the levels of nutrients like nitrogen are still high."

"Tangier Sound is the one area where we have some concern," said Magnien. "That area has had such a high population of grasses, extremely large acreage for years -- it's one of the

reasons why they have such a terrific crab industry there. If this trend continues, there might be some people who see it affecting their livelihood."

Growth areas

Elsewhere, though, bay grasses boomed. They expanded by more than 20 percent in the Gunpowder River, the Magothy and the Severn on the Western Shore, and in the Chester, parts of the Choptank and Eastern Bay on the Eastern Shore.

At the site of yesterday's press conference on the South River, a new bed of horned pondweed has appeared at the end of Betty Edmondo's dock, just beneath a high bluff where archaeologists are excavating the ruins of Londontown, a 17th-century settlement.

Bay scientists said the water isn't as clear as the pristine river that Londontowners knew. They estimate algae-growing nutrients then were about one-seventh what they are now. And the slender, yellow-green grasses aren't as thick as in Colonial times, when the plants grew practically everywhere that sunlight reached the bottom -- covering as much as 600,000 acres of the bay floor.

Creatures caught

But biologists Kent Mountford and Peter Bergstrom waded through the grassy shallows, quickly collecting a net full of creatures that the settlers would have known well:

Young croakers, still too small for the frying pan. A lone menhaden and a tiny young needlefish. Baitfish such as silversides and mummichogs. Grass shrimp by the dozens, food for all the rest. Stingless comb jellyfish that sparkle at night "like stars bursting, producing a brilliant blue light," said Mountford. And in the dozen-odd crab pots scattered off the dock, about 50 plump blue crabs.

"Not a bad morning's harvest," said Mountford.

The bay gleanings, like the rebounding grasses, were hopeful signs, said Matuszeski, "showing us that the bay is getting cleaner and clearer."

Pub Date: 6/03/98

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