The state's largest natural oyster bed has been shut down. That's due to several illegal harvests which culminated last week in a boat chase.
Oysters are filter feeders, which means they need to maintain a steady flow of water through their gills to survive.
"Oysters are bio-accumulators, so they feed on what's in the water," said David Carey, with the state Department of Agriculture. "But while they're feeding on what's in the water they also accumulate any contaminants that are in the water."
Carey said that's the case for many oysters at the base of the Housatonic River, where water quality isn't the cleanest thanks to three nearby sewage treatment plants. But, he said oysters are resilient. Put them in cleaner water and their filtration essentially works in reverse: cleansing the oysters.
Because of that, the state requires fishermen harvesting oysters from the base of the Housatonic River to only take smaller ones -- which are not big enough to sell commercially -- and transfer them to cleaner waters in Long Island Sound.
"That's why we're moving them and transporting them out to cleaner waters, so we reduce or eliminate those hazards," Carey said.
There, the oysters spend at least six months cleaning themselves up -- and growing to a size that makes them legal to sell. But in recent weeks, Carey said several harvesters broke that rule -- transporting potentially contaminated oysters that were already big enough to sell.
"They had market-sized oysters on their vessel and they had left the river to go plant those oysters on their beds -- that's not allowed.," Carey said.
Things got dramatic on Friday , when two vessels sped away from environmental police -- cutting evasive maneuvers in the water -- while dumping oysters overboard.
Of the eight harvesting companies working the the area -- Carey said only one has been consistently following the rules. He said the main motivation for breaking the law is money.
State officials will keep the Housatonic bed closed during the summer, and hope to have more aggressive oyster supervision programs in place this in the fall.