Remarkable shellfish


To the Editor:

The longer I work with bivalve shellfish, the more impressed I am with what a remarkable life form they are and what a key role they play in the wellbeing of both the planet and humankind. One would be hard pressed to design an organism more beneficial or resilient.

In past years I’ve pontificated about archaeological evidence that shellfish provided a major source of nutrition for ancestral human populations and that modern nutritionists believe shellfish are a perfect food, providing high protein, low-fat, with healthy amounts of essential vitamins, minerals and fatty acids.

I’ve told you that ecologists confirm their key role in marine food webs and the importance of oyster reefs to maintaining marine biodiversity. Environmentalists are keen to exploit their ecological services to remediate poor water quality and sequester excess global carbon dioxide. Gourmet chefs and “foodies” praise their superior flavor, while futurists concerned with global food shortages recommend them as a sustainable, efficient protein source low on the food chain. An acre of farmed mussels provides over 1,000 times more meat than an acre of pastured beef. Closer to home, in the aftermath of the collapse of the “virtual” economy, they provide a real and honest source of wealth and employment for wild harvesters and local shellfish farmers alike. It’s pretty obvious that bivalve shellfish have nurtured us from our very beginnings, do now, and are likely to play a part in our future salvation.

Now that we’ve reviewed their benefits, let me tell you a little about their resilience. It too is quite remarkable. Bivalve shellfish have been around in an evolving variation on a theme since the Early Cambrian period about 600 million years ago. Now, that’s a strong argument for the shelled lifestyle. Equally important to their persistence is the enormous fecundity inherent in shellfish and oysters in particular. It has been reported that a female oyster can release 60 million eggs over the course of one spawning season. During just one spawning event at our Shellfish Hatchery this summer, we estimated collecting over 300 million eggs from 23 female oysters. Not to be outdone, the nine male oysters that spawned released easily 10 times that amount of sperm.

Shellfish have a remarkable ability to rebound, if 1) a critical mass of broodstock is present, and 2) environmental conditions are favorable. The key mission of our shellfish program is to maintain that critical mass of broodstock in the Island ponds. To that end we annually produce millions of seed shellfish for release in the ponds. This year with ideal environmental conditions, our efforts, especially in the great ponds, were generously rewarded. Oyster spat collected on almost every hard surface in Tisbury and Edgartown Great Ponds.

The take-home message: there’s a lot more to shellfish than “what’s for dinner?”

For a litany of the right reasons, our Island shellfish deserve our appreciation, help, and protection.

And, if given half a chance, they are more than capable of returning the favor a thousand fold.

Richard C. Karney

Shellfish Biologist and Director

Martha’s Vineyard Shellfish Group