Invader crab may find its place -- on dinner plates

Haute cuisine: Long regarded a marine pest, the European green crab may be selectively harvested as a seafood delicacy

By Environmental News Network staff

Biologists in Maine will soon study a new — and delectable — way to eradicate a nearly century-old marine nuisance: the invasive, disruptive and hardy European green crab.

Bill Walton and other researchers at the Beals Island Regional Shellfish Hatchery in northern Maine will examine the biological feasibility of harvesting Carcinus maenus, a well-known and well-traveled marine pariah that competes with native shellfish for limited, native resources.

The Maine Technology Institute a nonprofit organization that promotes technological and economic advances in the state, awarded Walton a $10,000 grant to conduct the study. He hopes to finish the first phase of his research in January.

Walton and colleagues believe that the crab, which has wreaked havoc on Maine's shellfish industry since the early 1930s, can be selectively harvested and marketed as a seafood delicacy.

"Currently, the green crab is viewed only as a pest species," says Walton. "The crab tends to eat what we eat. It's incredibly tough. And generally speaking, its presence in the water means fewer clams and lobsters. So, we'd like to turn around these negatives and make them into a positive."

Using the successful model of the Chesapeake Bay blue crab, Walton and his team of researchers propose harvesting the green crab during its annual molting stage -- a three-day period when the crab sheds its tough outer shell, gorges on water and forms a new, larger shell from sea-water minerals.

"If we knew what to look for, we could literally read the crab's shell to determine when it should molt and when we should get it to market," says Walton. The researchers will focus on practical ways for fishermen to identify and select pre-molting crabs.

Some scientists warn that a harvest of green crabs could disrupt Maine's delicate marine environment

Though the voracious and disruptive green crab has few, if any, friends among scientists and fishermen, some scientists warn that a green crab harvest could disrupt the state's delicate marine environment.

"Changes to nature don't occur in a vacuum," cautions Kevin Lafferty, a U.S. Geological Survey marine ecologist who studied a similar green-crab invasion in coastal California waters. Noting that the harvest of other so-called nuisance species, such as the once-ubiquitous California sea urchin, often takes an unexpected toll on the environment, Lafferty suggests moving deliberately with the study, making sure that all the research questions are answered before harvest of the crustacean begins.

Like California, Maine has a history of harvesting marine species once considered aquatic pariahs.

"If you want to target and reduce a fish stock, a sure bet is to make it into a fishery," says Lafferty.

But few scientists or fishermen in Maine will shed a tear for a threatened green crab population, Walton says. At worst, he says, a successful green crab harvest could create a market and a fishing industry dependent on sustainable stocks of the pariah. But that, he says, is doubtful.

"The goal here is to reduce the crab's population," says Walton. "Believe me, we don't ever want this to be a fishery that needs protecting."

Copyright 2000, Environmental News Network, All Rights Reserved

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Beals Island Regional Shellfish Hatchery
European green crab
University of Maryland Sea Grant Program
MIT - Exotic Invasive Species.
Maine Technology Institute
Chesapeake Bay blue crab
U.S. Geological Survey

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