Maine Lobsters Threatened By Climate Change, Scientists and Industry Warn

Polar bears aren’t the only animals affected by climate change -- a warmer world could soon be threatening that centerpiece of a New England summer: the Maine lobster.

And what’s bad news for the Maine lobster is likely bad news for Maine. These tasty cockroaches of the sea (they share a phylum, Arthropoda, with insects) generated $338 million in economic activity for the state in 2012. The lobster industry also employs 3,000 full-time and 2,500 part-time harvesters, according to the Maine Department of Marine Resources.

On Tuesday, a coalition of Maine scientists, businesses and environmentalists called on Mainers and state officials to support President Obama’s recently announced carbon emissions reduction plan. One of the key points of that plan involves capping emissions from existing power plants, which account for more than a third of all U.S. carbon emissions.

"There is a problem. We are beginning to see the effects of climate change in the Gulf of Maine," Emmie Theberge, a spokesperson for the Natural Resources Council of Maine told the Portland Press Herald. "And the oceans are more sensitive to climate change."

Lobsters are cold-blooded, and at the mercy of the temperature of the surrounding ocean. As the waters get warmer, they have to expend more energy to breathe. Breathing less easily places more stress on the lobster, and may make it more susceptible to pathogens. More and more New England lobsters are turning up with shell diseases caused by bacterial infections. The rate of such infections has been strongly associated with spates of days where the ocean temperature exceeds 68 degrees Fahrenheit, according to the New England Aquarium.

Surprisingly, ocean warming has coincided with an increase on lobster numbers in the Gulf of Maine, possibly because the warmer waters allow for lobster larva to hatch earlier and grow more rapidly. Overfishing by humans has also depleted the numbers of the Atlantic cod, which preys on lobsters.

But lobsters may be victims of their own success. Booming numbers – along with a phenomenon where the lobsters shed their shells earlier than usual -- led to a glut of lobsters last spring that drove prices down. Plus, the lobsters in the Gulf of Maine may be doing well, but southern New England fisheries are languishing as the crustaceans move north, seeking out colder waters. If the temperature keeps rising, they may abandon Maine as well.

Another unexpected consequence of the warming waters and the increase in lobster numbers is like a true New England horror story: cannibal lobsters. While it’s long been known that lobsters will attack each other when confined in a small space, this behavior had not been observed in the wild until now.

"We've got the lobsters feeding back on themselves just because they're so abundant," University of Maine marine scientist Richard Wahle told Reuters last December. "It's never been observed just out in the open like this," he said.