ANNAPOLIS, Md. (AP) - Oysters in the Chesapeake Bay have been all but wiped out, but amateur conservationists are signing on to the growing hobby of home aquaculture to help bring the struggling bivalves back.

The Chesapeake Bay Foundation has sent out thousands of wire cages over the last decade to people in Maryland and Virginia willing to grow oysters under home docks for nine months and return them for "planting" on sanctuary reefs on the Chesapeake's tributaries.

Though the Chesapeake oyster is at an estimated 1 percent or less of its historic bounty in the bay, a victim of water pollution and sediment runoff from development, the nonprofit environmental group and its volunteers have put roughly 7 million oysters in sanctuaries since 1997.

"They're dirty little guys, and they don't smell good, but you always feel really good after you plant them," said Tiffany Granberg, a CBF employee who loaded up several dozen buckets of homegrown oysters Thursday on a boat docked outside the group's Annapolis headquarters.

Volunteers pay $75 for four oyster cages and a seminar on how to raise them. In the fall, they get several thousand "spat" - baby oysters the size of the nail on one's pinky - and instructions on how to raise them. The volunteers tie the cages to docks, leaving them a few inches below the water, and haul them out twice a month or so to rinse them.

Raising oysters for several months near the surface helps keep oysters from getting silted over, a major cause of oyster demise in the Chesapeake. Rinsing the spat keeps muck off and allows the oysters to breathe. There's no worry the gardeners will eat their oysters; pollution has led to an advisory against human consumption for oysters raised in most Chesapeake tributaries.

After the first year, gardeners can return for a new crop of oysters without paying the $75 fee.

In late May and early June, the volunteers return the oysters (now about an inch long) to the foundation, which deposits the oysters on reefs, usually in tributaries, that are off-limits to commercial harvesting.

Scientists with the foundation say they're not sure the effort has yielded much in the way of environmental benefit. Oysters are water-clearing filter-feeders but struggle to overcome the poor water quality that plagues all the Chesapeake's critters.

But the home oyster gardening effort yields great rewards in educating citizens and giving them a chance to participate in Chesapeake restoration, participants say.

"All you really need is a dock and hose and some rope," said Jamie Attanasio, 10, of Potomac, Md., who raised four cages off her aunt and uncle's dock on a Patapso River tributary after hearing about the program in school. Jamie returned her oysters this week, and was pleased to learn 94 percent of the spat she received lived through the winter. It was an effort that impressed her parents.

"Jamie decided she wanted to clean the bay, and I laughed and said, 'Well, how are you going to do that, you're 10 years old?'" said Jamie's mom, Ann Attanasio. "But she did a great job."

Organizers of the home gardening effort say it's getting more popular. Though the state of Maryland grows millions of oysters a year for use in research and state restoration efforts, the foundation's program is the only one aimed at amateurs. About 1,600 households have taken part.

"We realized early on in the oyster restoration realm that if all we had was a bunch of scientists and state agencies and maybe some scientists from nonprofits doing restoration, without any input and help from the public, it wasn't going to get that far," said Stephanie Reynolds, a fishery and oyster scientist with the foundation. "We needed the public involved, literally roll-up-your-sleeves involved."

Home gardeners don't usually see their oysters reach their final homes, but the activity grows in popularity each year.

"We add people every year and we don't have a lot of dropouts. People who have docks always say, 'Oh, I'd like to do that,'" said Stephen Gauss, a retired astronomer and home oyster gardener from Shadyside, Md. "It's a lot of fun but it's also something you can see right away helping out the bay."

On the Net:

CBF Home Oyster Gardening program: http://www.cbf.org/site/PageServer?pagenameaction_outdoors_oysters