Bookmark & share:

E-mail this page E-mail a letter to the editor Reader Comments (below)

BY TOM BELL
MaineToday Media, Inc. 04/08/2008

MaineToday Media, Inc.

A voracious eater, the dogfish fills its belly with anything it finds. It hunts in packs, dashing among schools of fish and attacking even within fishermen's nets, biting through the mesh.

And fishermen say the Gulf of Maine is thick with them.

"It's astonishing," said Charles "Puggy" Felch, who has fished off the New Hampshire coast for more than four decades. "I have never seen as many dogs as there is now."

In 2007, while catching 61,000 pounds of cod, Felch discarded 205,000 pounds of dogfish. For every cod he caught, he threw away three dogfish.

He threw them back because it was illegal to keep them -- there are quota limits aimed at protecting dogfish.

He said dogfish are preying on juvenile cod, making it difficult for cod stocks to rebound.

"If the state wants to bring deer back, you wouldn't introduce coyotes and wolves," he said, "but this is what they have done."

New England fishermen for centuries have despised the dogfish, which is a shark that grows to about 3 feet in length. Dogfish have almost no commercial value. They destroy fishermen's nets, and they eat valuable groundfish as well as whatever the groundfish eat, such as herring and mackerel.

Now some fishermen and scientists say the shark has become so abundant that it has replaced cod at the top the food chain in the Gulf of Maine.

No cause or effect has been determined. Still, Atlantic cod has failed to rebound, during the same time period that the dogfish has emerged as a predominant member of the Northeastern continental shelf ecosystem, said James Sulikowski, a biologist at the University of New England who has studied dogfish with the help of fishermen.

Dogfish are such skilled predators and operate in such large numbers that they have the potential to force a species out of an area simply by out-competing it for food, he said.

Mike Breton, a tuna fisherman who lives in Gray, said fishermen are now paying the price for overly cautious federal managers.

He said dogfish are so numerous that it's impossible to fish for tuna with a rod and reel because fishermen catch dogfish any time they throw a line in the water.

Conservationists, though, say the dogfish population is not as robust as it may appear and argue that the restrictions should remain until the stock is fully rebuilt, which could take another decade.

No one fully understands the ecological role dogfish play in the ocean, said John Williamson of Ocean Conservancy. Though fishermen consider them a nuisance, he said, that does not negate the legal and ethical responsibility to manage dogfish in the same way as other species.

"They are God's creatures," he said. "Therefore, they have a purpose."

The controversy over the species illustrates the challenges of managing a diverse and complex ecosystem.

Federal law requires that managers treat all species equally -- even the ugly and unpopular ones.

The law also requires that each species be managed independently, even though the dogfish and 18 groundfish species share the same habitat and interact in the same complex food web.

Fishermen never purposely fished for dogfish until the 1990s, when the British began using the shark's bland-tasting white meat as a replacement for cod in fish-and-chips dinners.

The fishermen targeted the large females because they were easier to process and fetched a better price.

In 2000, alarmed by a plunge in the number of the large females, the federal government imposed strict rules on dogfish catches and effectively put the commercial fishery out of business.

Many of the young males that escaped the fishermen's nets are fully mature now, accounting for what appears to be a dogfish boom. Males outnumber females 7 to 1.

Scientists say the large number of males also masks a generational gap.

The life cycle of the dogfish is a lot like that of a human being.

Unlike other fish that mature quickly and lay millions of eggs, dogfish grow slowly and cannot reproduce until they're 12 or 13 years old.

Dogfish carry their pups two years before they are born, and average only six pups at a time. They can live as long as 40 years.

That means the females that were caught in huge numbers in the 1990s never reproduced. Today, those females are missing and so are their offspring, said Paul Rago, a biologist at the Northeast Fisheries Science Center in Woodshole, Mass.

"That debt has to be repaid at some point," he said.

Bookmark and share this story: