It’s not uncommon for fishermen and scientists to have opposing viewpoints about stock assessments of ocean species, but rarely is the difference in viewpoint as pronounced as the debate over the status of two sharks in the Gulf of Maine.

Portland-area fishermen have gone on record to say that porbeagle sharks are becoming a nuisance species at the same time that scientists continue to warn that the species is on the brink of extinction. And while both fishermen and government scientists agree that the Atlantic spiny dogfish stock has recovered in New England waters, fishermen contend that the catch quotas for these sharks are being kept too low for a species that is perceived to be outcompeting more valuable fish.

Consensus in the international debate over how to protect the two shark species is equally rare. Canada has been actively blocking new protection for the porbeagle shark to protect its local porbeagle fishery. And a vote by an international governing body to offer greater protection for the porbeagle was derailed by a parliamentary maneuver and a lost vote.

Sharks have a P.R. problem, said Sonya Fordham, president of Shark Advocates International. They have yet to recover from their portrayal in the movie Jaws, and fishermen often view them as unwelcome competition.

“This can be a common obstacle for shark conservation,” said Fordham.

Certainly, the porbeagle isn’t making any friends among Portland-area fishermen, according to a 2010 article in Gloucester Times. In the article, gillnet fishermen complained they were encountering as many porbeagles in a day as they used to see in an entire offshore fishing trip. The porbeagles are eating the fishermen’s catches and destroying valuable fishing gear in the process, fishermen said.

“We often can’t get [the fish] to the boat,” said Windham captain Steve Hodgkins, a veteran gillnet fishermen, in the article. “They’ll sit there and eat 6,000 to 7,000 pounds of fish a day from us.”

In Maine, Midcoast fishermen share their hauls with the spiny dogfish, said Ben Martens, director of policy for the Midcoast Fishermen’s Association.
“The dogfish population has skyrocketed,” said Martens.

Fishermen contend that not only do the dogfish eat their catch, they also outcompete codfish and other valuable predatory fish. While there is a market for dogfish, a pound of the shark sells for a fraction of what a pound of codfish can fetch.

To add insult to injury, the spiny dogfish have spiky protrusions that pack the same punch as a bee-sting.

“They’re not much fun to work with,” said Martens.

Not all fishermen agree that more sharks are a problem. Sport fishermen say the large predators attract more customers. Portland sport fisherman Joe Tufts believes dogfish are a pest, but he’s happy with the reemergence of porbeagles and thresher sharks.

“To me, they’re good for business,” Tufts said.

But scientific surveys show that the porbeagle still is on the brink of extinction, with the current population at only 10 percent of its levels in the 1980s. The spiny dogfish population has become relatively stable, but scientists still are concerned about the shark’s future. Conservationists say that perceptions of shark numbers may be skewed by the boom-and-bust cycles of the fish they feed on and by the aggravation that the sharks cause.

“There’s almost no shark that you see in New England that isn’t just a remnant of its population,” said Sharon Young, marine issues field director for the Humane Society of the United States.

And there still is so little known about the role sharks play in the overall health of the Gulf’s ecosystem. Sharks that appear to be nuisances may be contributing to overall fishery health, said Young. She cited a landmark University of North Carolina study showing that large North Atlantic sharks helped the mid-Atlantic scallop industry by feeding on rays that preyed on the scallops. Once the large sharks disappeared, the rays multiplied and nearly wiped out the scallops.

“We’re finding things in nature to be inconvenient to us,” said Young, “but ecosystems exist in a balance.”

Local debate over sharks mirrors the international debate. The international governing bodies overseeing shark protection and trade, the ICCAT and the CITES, have passed measures restricting shark trade in recent years. But Canada has blocked several proposals restricting trade and protection of the porbeagle in an attempt to protect its own porbeagle fishery.

A 2010 vote to enhance porbeagle protection passed the two-thirds majority needed by the CITES governing body, only to be defeated in a second vote called by an obscure parliamentary maneuver. The measure fell one vote shy in a second round of voting. Afterwards, it was discovered that the vote of Germany, the country that first proposed the enhanced protection, was not recorded, reportedly due to an electrical glitch.

Craig Idlebrook is a freelance writer living in Somerville, Mass.