Scientists want you to save those oyster shells

DURHAM, N.H. -- Along with plastic, cardboard, glass, and paper, area residents can now add oyster shells to their list of recyclables.

The shells are being collected for reuse in a program involving citizens and scientists interested in returning oysters to the Great Bay. Since 1993 the area's oyster population has declined by 95 percent, so the University of New Hampshire and the state chapter of the Nature Conservancy this summer sought out public help to bring the mollusks back.

Residents, commercial shellfishermen, restaurants, and seafood markets are being asked to bring in any discarded shells they may have to the state's first oyster shell recycling center, which opened Labor Day weekend outside the university's Jackson Estuarine Laboratory in Durham.

``In the past a lot of these shells were just brought to the dump, which is not good," said Jenn Greene, who runs the recycling program. ``It's very important that we use the recycled shells as a substrate to grow the baby oyster on at the lab. . . . That's what they attach to normally."

The discarded shells literally form the base of a program to rebuild the oyster population in the Great Bay to what it once was centuries ago, said Ray Grizzle, a resident faculty member at the lab. Oysters can provide refuge to other species of fish and plants.

When oysters spawn, the larvae they produce attach to the nearest solid surface, usually another oyster shell. Over generations this process can form oyster reefs that can grow 6 feet high, Grizzle said. Such structures once dominated East Coast estuaries like the Great Bay.

Over the past few years, Grizzle has brought in shells and larval oysters from out-of-state and placed them in tanks at the lab. Once the larvae fastened to the shells, they were moved to cages suspended from docks floating in front of the lab and then to strategic points in the Great Bay estuary. Since 2000, it has been just Grizzle and staff working on the project. Now that effort is expanding.

This summer, the lab recruited waterfront residents in Durham, Dover, Newmarket, and Newington to grow out a larger crop of baby oysters, or spat, in cages in front of their homes. The problem now is they need more shells.

As similar programs have been springing up in other East Coast states that once supplied Jackson Lab, oyster shells have been getting scarce.

``We've been driving as far as Maryland to get oyster shells," she said. ``If we can gather up these shells from our own state instead, then we wouldn't have to go to other states."

The shell recycling center is made up of a half-dozen rather ripe black trash cans on a trailer with white spay-paint signs noting which shells go where. There are cans specifically for local baymen who know their shells come from local waters. Other cans are designated for shells coming from restaurants or seafood markets, which could have gotten the oysters from outside the area.

There's a concern that shells from outside the area may carry bacteria or diseases local oysters haven't faced, Greene said. Such shells go through a quarantine process before being used to recruit larval oysters. Bacteria are being blamed for wiping out the oysters in the Great Bay. Over the past few years, the lab has been raising oysters Grizzle hopes have acquired a level of disease resistance.

The importance of this project goes beyond finding more oysters to feed New England seafood lovers, according to Grizzle and others. Oyster reefs were once a ``keystone" to the health of the Great Bay and estuaries like it up and down the East Coast, said Mark Zankel , deputy state director for the New Hampshire chapter of the Nature Conservancy, which has helped fund the project.

An important function the oysters served was cleaning the water, Zankel said. Oysters feed by filtering microscopic plants and animals called plankton out of the water. They also filter out a lot of sediment.

Clear water is key to growing a form of seaweed called eelgrass, a building block of East Coast estuarine ecosystems. With the oysters gone it's feared the eelgrass could disappear from the Great Bay as it has in similar bays along the East Coast.

``Filtered water is very important for the health of the eel grass -- that's why we're focusing on the oysters," Zankel said.

The recycling program started earlier this summer with 600 letters going out to all the state's commercial shellfish license holders asking them to bring in their empty shells. After its first week open, the center had about 4 bushels of shells, and Greene now wants to get the word out to restaurants and seafood markets.

Equally important to Jackson Lab's efforts to restore the oyster reefs are the waterfront residents growing the spat in the cages in front of their homes. Grizzle is looking for more help there, too.

So far, 16 residents are raising young oysters in front of their homes, but the lab has another 2 million spat it wants to find homes for.

``I'm glad to have people involved, but the more the better," Grizzle said. ``There has been a lot of interest, but if we had 50 or 100 people involved we could really make a go of it."

Among those involved are Ray Belles and Phyllis Bennett, who own land on the Oyster River that was once called Oyster Farms. They've been like doting parents tending to the cage of baby oysters tied to the dock in front of their home. Every Thursday they measure the oysters growing inside and check for starfish, crabs, and other things that like to eat them.

``What could be better than restoring oysters to the Oyster River," said Belles. "We're part of the regenerative process here. We're making things grow."