The flourishing green crab presents a significant threat not only to a major Maine commercial fishery – the $17 million soft-shell clamming industry – but also to the marine environment as a whole. As part of a multi-pronged approach to fighting the invasion, both the public and private sectors should make it as easy as possible for fishermen to catch and sell green crabs. This species is one visitor whose decline Mainers would be happy to witness.
Green crabs have been reported in Maine for more than 100 years, but the crustaceans weren’t seen in large numbers until relatively recently – when, scientists speculate, warming waters allowed the population to multiply and move north. The invasive species feeds on soft-shell clams and dislodges eelgrass, a marine plant that helps to stabilize sediment and to maintain fisheries and water quality.
Given how high the stakes are for the state’s marine habitat and its third-largest commercial fishery, Maine has to focus on removing green crabs from coastal waters as quickly as possible. As state marine ecology researcher Brian Beal told the Press Herald in February: “How do you get rid of an invasive species? You fish ‘em to death. We did an awful good job of reducing the population of sea urchins without even trying.”
State marine resources regulators are now moving in this direction, reviewing ill-thought-out rules that actually protect the invader. If urgently needed regulatory changes are approved, lobstermen would no longer need a license to sell green crabs, and they wouldn’t have to report what they’ve caught. The revised rules would also eliminate the restriction on taking green crabs caught unintentionally.
The private sector is also stepping up to address this menace, by helping to create a viable market for green crabs. Both Maine and out-of-state entrepreneurs are exploring how to use the species’ meat and shells. The meat can be processed for frozen meals and to feed farmed salmon, while the shells are a source of a compound called chitin that has medical and cosmetic applications.
Scientists are tracking green crabs and assessing the creatures’ impact on the health of Maine’s clam population, but there’s no reason why this work can’t be carried out alongside efforts to get rid of the invasive species. The gravity of the situation calls for bringing all of us on board for as long as possible until a workable solution is reached.