From the Mystic River Press
Flourishing oysters doing their part to clean Mystic River.
by Lee D. Vincent
December 12, 2006 (for Dec. 14 edition)
The most efficient cleaning crew in Connecticut doesn’t seem to work hard at all, but they are getting a lot done, 24 hours a day. All they do is sit there in a cool, dim light and get healthy while they make waste disappear. I’m talking about bivalves, of course – mainly about oysters.
Last week I attended the biennial Northeast Aquaculture Conference. Luckily for me, it was held right here in Groton. I thought the scientific parts would go over my head, but it was one of the most interesting and enjoyable conferences of a lifetime, thanks in large part to our local scientists from CT Sea Grant and UConn at Avery Point.
Once upon a time, around the first Thanksgiving, settlers or natives willing to wade in the cold water with a crude tool could feed several families with a reasonable amount of work. And now the oysters – especially in and around Groton -- may be on the way back to a level of abundance and value in our food choices that has been unseen in our lifetimes.
Between colonial times and now, a lot has happened that was bad news for oysters and other aquatic life. American industry made the flush toilet available everywhere. Storm sewers and sanitary sewers can now carry waste from far inland into our rivers and down to the tidal estuaries. But now that a few of our rivers and estuaries – like the Mystic River -- are again clean enough for oysters to thrive, the oysters are playing their own big part in furthering the clean-up. These results should give even more motivation for policies to keep our waters clean.
Oysters need fairly good living conditions, but they definitely aren’t looking for perfect water, either. It was only about eight years ago when I had some demonstrations from biologists at the Mystic Aquarium, that I (as a life-long big-city boy) understood that too much of nutrients is just as deadly to aquatic animals as is the rest of what we call pollution.
When rivers collect runoff from built developments, from lawns, gardens and farms, and accumulate sanitary sewage that hasn’t been ideally treated, it gradually climbs to a level that is too much for shellfish to thrive in the waters. When conditions are right, though, oysters are there to work while they grow toward their destiny in the kitchen. They love to process the water that comes their way, and a market-sized oyster cleans all kinds of stuff out of about one gallon of water every hour.
Since oysters don’t sleep much, (truthfully, it’s not easy to tell) they purify about 25 gallons of water in 24 hours. I know that a lot of scientific men and women read this paper, so here’s a treat for all of you: I was told last week that 1,485 oysters can completely eliminate the daily waste that is issued by one tourist. You say that’s an awful lot of oysters? Well there are an awful lot of happy oysters around here now. The Noank Shellfish Cooperative plants millions and millions of the highest quality of oyster seeds around Groton every year, including some of our recreational waters.
The oysters not only take nitrogen nutrients (that means fertilizer, to put it very simply) out of the water and make oyster meat with it; the rest of the nitrogen the oysters release is diatomic. That means that the nitrogen they release is a neutral gas. Oh, yes, even the great oyster cleaning crew leaves off some fecal waste of its own, and those deposits have gained a nice new name. It’s called biodeposits, and the scientists say that such biodeposits are really a boon for other aquatic creatures.
There are two preferred indicators of a healthy river estuary: green eelgrass and growing oysters. Both of them are thriving today in our area, from the Mystic River to Ram Island and beyond. The most exciting news for oyster growers is the fact that we have recently found proof that natural recruitment is taking place. That means that we have seen spat or young oysters being bred on their own rather than from seed that was planted by members of the Cooperative.
The Noank Shellfish Cooperative, now leasing the Noank Hatchery owned by the Town of Groton, is selling brand-name “Mystic” and “Noank” oysters as a premium-quality menu item in restaurants. They can assure top quality by controlling the broodstock and its seeds. Members of the Cooperative believe that oyster culture in our local waters is healthier than anywhere else in Connecticut, and their outlook is that the local industry of small growers will thrive.
Oysters: they’re a clean machine.
Lee D. Vincent is Assistant to the Town Manager and Chairman of the Groton Shellfish Task Force.