Friday, December 30, 2016

Fish Seek Cooler Waters, Leaving Empty Nets

There was a time when whiting were plentiful in the waters of Rhode Island Sound, and Christopher Brown pulled the fish into his long stern trawler by the bucketful.

“We used to come right here and catch two, three, four thousand pounds a day, sometimes 10,” he said, sitting at the wheel of the Proud Mary — a 44-footer named, he said, after his wife, not the Creedence Clearwater Revival song — as it cruised out to sea.

But like many other fish on the Atlantic Coast, whiting have moved north, seeking cooler waters as ocean temperatures have risen, and they are now filling the nets of fishermen farther up the coast.

Studies have found that two-thirds of marine species in the Northeast United States have shifted or extended their range as a result of ocean warming, migrating northward or outward into deeper and cooler water.

Lobster, once a staple in southern New England, have decamped to Maine. Black sea bass, scup, yellowtail flounder, mackerel, herring and monkfish, to name just a few species, have all moved to accommodate changing temperatures.

Yet fishing regulations, which among other things set legal catch limits for fishermen and are often based on where fish have been most abundant in the past, have failed to keep up with these geographical changes.

The center of the black sea bass population, for example, is now in New Jersey, hundreds of miles north of where it was in the 1990s, providing the basis for regulators to distribute shares of the catch to the Atlantic states.

Under those rules, North Carolina still has rights to the largest share. The result is a convoluted workaround many fishermen view as nonsensical. Because black sea bass are now harder to find in their state waters, North Carolina fishermen must steam north 10 hours, to where the fish are abundant, to even approach the state’s allocation. Mr. Brown and other New England fishermen, however, whose states have much smaller shares, can legally land only a small fraction of the black sea bass they catch and must throw the rest overboard. And New England states like Maine, where fishermen are beginning to catch black sea bass regularly, have only a tiny allocation and no established fishery.

“Our management system assumes that the ocean has white lines drawn on it, but fish don’t see those lines,” said Malin L. Pinsky, an assistant professor in the department of ecology, evolution and natural resources at Rutgers University, who studies how marine species adapt to climate change. “And our management system is not as nimble as the fish.”

The mismatch between the location of fish and the rules for catching them has pitted recreational fishermen against commercial ones and state against state. It has heightened tensions among fishermen, government regulators and the scientists who advise them and raised questions for fishery managers that have no easy answers. (...)

Although such shifts in allocations are possible, said Tom Nies, the executive director of the New England Fishery Management Council, in practice they are difficult to execute.

“If you’re giving fish to somebody, you’re taking them away from somebody else,” Mr. Nies said.(...)

Richard J. Seagraves, the senior scientist for the Mid-Atlantic Fishery Management Council, said that in a series of surveys distributed and town hall-style meetings held by the council, “the most pressing concern expressed by all parties was the failure to address ecosystem considerations, like a changing climate and the physical effects on fish stocks.”

The government periodically monitors fish species to see if they are thriving or at risk of extinction. The surveys are intended to determine how much fishing a given species can sustain, in order to avoid overfishing.

But even in the best case, trying to estimate the size of fish populations is an uncertain proposition. And the migration of species in response to warming temperatures has made the task considerably harder.

“From a scientific perspective, there are some really interesting questions,” Dr. Pinsky said. “Where did the fish go? Did we eat them? Or did they go somewhere else? Those are questions we haven’t really had to grapple with.”

by Erica Goode, NY Times |  Read more:
Image: Christopher Capozziello