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Kristan Porter grew up in a fishing family in the fishing community of Cutler, Maine, where he says all roads lead to one career path: fishing. (Porter's father was the family's lone exception. He suffered from terrible seasickness, and so became a carpenter.) The 49-year-old, who has been working on boats since he was a kid and fishing on his own since 1991, says that the recent warming of Maine's cool coastal waters has yielded unprecedented lobster landings.
The lobster industry in Maine is riding the crest of record prices and a record catch last year. This year, exports of the state's signature shellfish more than doubled last year's sales. But a new study from the University of Maine's Darling Marine Center and the Bigelow Laboratory for Ocean Science found that baby lobsters won't survive in warmer waters.
Warming waters in the Gulf of Maine threaten American lobster fisheries.Dan Zukowski
Southern New England lobster fisheries have already collapsed. The National Oceanic and Atmospheric Association reports that over the past 10 years, the Gulf of Maine has warmed 99 percent faster than any other sea in the world. As a result, cod have virtually disappeared from the region. Lobster, like cod, are a cold water species.
A new study, published today in the ICES Journal of Marine Science, details the effect of warmer waters on the larval development of American lobsters. They found that when the water was 5 degrees Fahrenheit warmer than currently found in the Gulf of Maine, these baby lobsters "experienced significantly lower survival." Five degrees is how much the the United Nations' Intergovernmental Panel on Climate Change projects the Gulf of Maine's temperature will warm by the end of the century.
Export markets for Maine lobster have grown dramatically.Credit: Portland Press-Herald
Maine's waters have long yielded large amounts of high-quality lobster. But as southern New England lobsters went into decline, the industry in northern New England flourished. The lobster population in the Gulf of Maine doubled in the past 20 years. In 2015, Maine lobstermen landed a record $495.4 million, or 121.1 million pounds.
Demand from China and other Asian markets is driving growing exports, which reached $103 million in the first half of 2016. From 2010 to 2015, shipments to China rose from just $100,000 to $20 million. But the waters that produce this bounty are at risk.
The bounty that fed Native Americans for 11,000 years and early European colonizers derives from a unique geography. The Gulf of Maine is bounded on the southeast by Georges Bank and Browns Bank, creating an almost enclosed sea. From the northwest, it's fed by nutrient-rich cold waters of 25 river systems that drain 250 billion gallons of water per year into the gulf. At the head of the gulf, tides rise and fall 50 feet in the Bay of Fundy. Cod, herring, salmon and lobster thrive in this environment.
"Warm-water invaders are gaining a toehold, and those that already had one are taking over," reported the Portland Press-Herald in a special series published in 2015. In recent years, changes in the Gulf Stream have allowed more warm water to invade the Gulf of Maine. There has been a slow but steady progression north for the best lobster grounds. In the 1970s, it was in Casco Bay, outside Portland, but today it is some 80 miles north in Penobscot Bay.
Now, warm-water species are appearing off the shores of Maine. Squid, sea bass, green crabs and Asian shore crabs are among the invasive species. They've destroyed eelgrass and created ecological impacts that have yet to be determined. The University of Maine study showed that baby lobsters grow faster in warmer waters but don't survive as well. That could mean that Maine's lobsters will migrate north in search of colder Canadian waters.
"Ask any commercial fisherman here about climate change, and he'll tell you that it's wreaking havoc," the operations supervisor at the Portland Fish Exchange told me this summer. Now, researchers know why.