For the next few weeks, more than 90 people will pull approximately 500 cages out of the water and hopefully find them filled with baby oysters known as oyster spat.

Judy Plott pulled her cages up Tuesday. She has been growing oysters off her dock for more than a decade, and this year she joined up with South River Federation's Oyster Gardening on South River program. 

"Our neighborhood got involved about 10 years ago because our cove, which is Little Aberdeen Cove, got a little, tiny bit of funding, but a lot of enthusiasm about putting oysters on almost every pier in our entire cove."

Plott dropped her oysters off with Jennifer Carr, South River Federation's volunteer coordinator. The two discussed the less than stellar set—which means how many oysters started growing on each shell. 

"This year the numbers are significantly lower because we had Hurricane Irene and Tropical Storm Lee come in September," Carr said. "They dumped such tremendous amounts of fresh water in the bay and killed a lot of the oyster spat."

Carr and South River Federation board member Kevin Green met Plott after they returned from planting oysters grown by his community in its private marina.

Green lives in Hillsmere, and there are nearly 50 cages hanging off the docks annually—the most of any community on the South River, Carr said.

The growing process starts in the fall when old, discarded oyster shells are collected. Carr said they are put in a tank with live oysters, which tricks them into mating.

The larvae swim around for a few weeks before finding a good place (i.e., an old oyster shell) on which to grow. Carr said the fertilized shells grow in cages hanging off private docks until around early June when they are pulled up from the water and planted.

Although, the word "planted" is a bit misleading.

"It’s not like planting in the ground like you would a flower," Carr said. "You literally dump them off the side of the boat, and they fall into the oyster reef."

South River Federation partnered with the state's Maryland Grow Oyster program when it started in 2008, and all oysters collected from private, volunteer growers around town will be planted into an oyster reef in Glebe Bay.

The reefs—which function much like coral reefs—are selected based on what would give the oysters the best long-term chance of survival.

"This is the third year on this reef," Carr said. "We pretty much wait every year and the state will say use Glebe again or if they say it's time to move on and let us know where to go."

The oyster sanctuary on Glebe Bay is protected by the Department of Natural Resources, and people caught harvesting from it can be fined.

Carr said the oyster population is at about 1 percent of historic records for the area, and she thinks it's due in large part to the amount of pollution in state rivers.

"Oysters are filter feeders meaning they are going to filter in all that water and eat what's in the water," Carr said. 

Growing oysters has another benefit, Carr said.

"When the people hang these cages off their private piers, it creates habitats for other animals," Carr said. "When you pull up the cages you can find mud crabs, shrimp, different types of fish and even some small blue crab. It enriches the local biodiversity."

Plott seconded that fact, and said kids from around her neighborhood get a real kick out of seeing all the fish swim in and out of the cages.

"Kids just have an instant interest and much deeper understand and concern when they have had their hands on these animals and watched them grow or not grow," Plott said. "Either way, there's no failure."