"They don't have an incentive to fish sustainably," Norse said. That's why he urges the United Nations and individual countries to stop deep-sea fishing "unless you can prove that you're fishing sustainably."
Elliott Norse, president of the Marine Conservation Institute and the paper’s lead author, said the world has turned to deep-sea fishing “out of desperation” without realizing fish stocks there take much longer to recover.
“We’re now fishing in the worst places to fish,” Norse said in an interview. “These things don’t come back.”
As vessels use Global Positioning System devices and trawlers, which scrape massive metal plates across the sea bottom, the catch of deep-water species has increased sevenfold between 1960 and 2004, according to the U.N. Food and Agriculture Organization.
“What they’re doing out there is more like mining than fishing,” said Kevin Hassett, director of economic policy studies at the American Enterprise Institute.
The estimated mean depth of fishing has more than tripled since the 1950s, from 492 feet to 1,706 feet in 2004, according to Telmo Morato, a marine biologist with the department of oceanography and fisheries at the University of the Azores in Portugal and one of the paper’s authors.
Fishing subsidies help sustain this practice, according to Rashid Sumaila, the paper’s other author, who directs the University of British Columbia Fisheries Centre. He said high-seas trawlers around the world receive roughly $162 million each year in government handouts, which amounts to a quarter of the value of the fleets’ catch.
“That is what is keeping most of them in business,” Sumaila said.
Bottom-trawling can crush deep-sea corals, which can live for as long as 4,000 years, the scientists noted. Some fish species of the deep live for more than a century, and while they can spawn many eggs, there can be several years in which juveniles fail to make it into adulthood.
Orange roughy, which Australia declared a threatened species in 2006, take 30 years to reach sexual maturity and live up to 149 years. The leafscale gulper shark, one of several deep-water sharks targeted for its liver oil, “matures late, has only 5-8 pups per year and lives to be 70 years old,” the authors write.
Maria Damanaki, the European Union’s commissioner for maritime affairs and fisheries, said in an interview that she would like to reduce fishing on the high seas and cut subsidies for deep-sea trawlers.
“I’ll try. I really agree there’s a danger there, so we have to be prudent,” said Damanaki, adding that nations such as France, Denmark, Portugal and Spain resist such efforts. “We have to try to persuade them to stop this.”