Warming ocean is a concern

Imagine Cape Cod without cod. Maine without lobster. The region's famous rocky beaches invisible, obscured by constant high waters.

It's already starting to happen. The culprit is the warming seas — and in particular the Gulf of Maine, whose waters are heating up faster than 99 per cent of the world's oceans, scientists say.

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The Gulf of Maine is heating up faster than the world's oceans.

Long-established species of commercial fish, like cod, herring and northern shrimp, are departing for colder waters. Black sea bass, blue crabs and new species of squid — all highly unusual for the gulf — are turning up in fishermen's nets.

The Gulf of Maine's warming reflects broader trends around the North Atlantic. But the statistic — accepted by scientists at the National Oceanic and Atmospheric Administration — underscores particular fears about the gulf's unique ecosystem and the lucrative fishing industries it supports for three U.S. states and two Canadian provinces.

"These changes are very real, and we're seeing them happen quickly," said Malin Pinsky, a biology professor at New Jersey's Rutgers University who studies ocean temperature change and was not involved in the research that resulted in the 99 per cent statistic.

It is a rallying point for environmental activists, who see the response to the temperature rise and its impact on fisheries as a touchstone for the global debate about climate change.

"The warming is already here," said Jeff Young, a spokesman for Pew Charitable Trust's oceans project, which has campaigned in favour of restrictions on fishing for herring, another species leaving for colder water. "And we have to deal with it."

The rising waters in the Gulf of Maine — a big dent in the east coast stretching from Massachusetts to Nova Scotia and New Brunswick — have interfered with the work of Diane Cowan, founder of the Lobster Conservancy, who has conducted lobster censuses in New England for 22 years.

The shore of a cove off Maine's Friendship Long Island has long been the best site on the east coast to find baby lobsters, she said. Around 2007, she couldn't lift a rock without finding one, and usually found several.

But the rising sea has prevented her from getting there much since 2010, she said, because it's almost always underwater.

The rising sea is connected to the warming waters because higher temperatures make the water less dense, said Bob Steneck, a professor at the University of Maine's School of Marine Sciences.

Until 2004, temperatures in the gulf were increasing by about 0.05 degrees Fahrenheit per year since 1982, about in line with worldwide trends, said Andy Pershing, chief scientific officer at the Gulf of Maine Research Institute and the man behind the 99 per cent figure. But then the pace accelerated to about a half-degree per year — nearly 10 times faster.

Scientists are not certain why. The rest of the oceans are also warming, albeit not as fast, as increased carbon dioxide in the air has contributed to rising temperatures, Pershing said.

Another possible cause, Pershing said, is that shifts in the Gulf Stream, the Atlantic current that originates in the Gulf of Mexico and keeps Europe mild, warmed the ocean off the northeast United States.

The Gulf of Maine's temperature is expected to rise more than four degrees Fahrenheit by the end of the century, Pinsky said.