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Going Green: A cleaner catch

World Wildlife Fund rewards efforts to reduce bycatch

By Lisa Duchene
April 05, 2011

To help fishing boats harvest primarily their target catch and minimal amounts of bycatch, it helps to think like a fish. When haddock encounter a net, they tend to swim up into the water column and slowly drift back into the net. Codfish, on the other hand, tend to swim toward the bottom. 

Knowing how these two intermingling groundfish species, valuable sources of the whitefish supply, behave differently was critical to the design of a net known in New England as “the Eliminator,” or the Ruhle Trawl, which is engineered with smaller mesh at the top to snag the haddock and huge, eight-foot mesh at the bottom to allow cod to escape. 

In testing tows on Georges Bank, the Eliminator caught 83 percent fewer codfish than a conventional net.

The selective gear was designed among a partnership comprising Jon Knight, a net maker at Superior Trawl in Point Judith, R.I., father-and-son fishermen Phil Ruhle Sr. and Jr., and James O’Grady, also from Point Judith, and scientists from the University of Rhode Island. The Eliminator was re-named to the Ruhle Trawl in memory of Phil Ruhle Sr., a tireless advocate for the fishing industry who was lost at sea in July 2008. 

Use of the net allowed fishermen during the 2007-2008 groundfish season into certain closed areas of Georges Bank to harvest abundant haddock without hammering struggling cod stocks, providing seafood buyers with more haddock and behind-the-scenes assurance that it had been caught without harming the cod biomass. The Eliminator won a $30,000 grand prize in 2007 in the World Wildlife Fund’s (WWF) International Smartgear competition.

This year, the competition offers a grand prize of $30,000, two $10,000 runner-up prizes and a $7,500 special prize to an idea that reduces bycatch in tuna fisheries, via a partnership with the International Seafood Sustainability Foundation. WWF has identified tuna sustainability as its top global fisheries conservation priority. 

Bycatch is not only a big problem for U.S. seafood buyers, but for the world. The killing of non-target species can trigger regulations that keep fishermen from reaching target species and fish from reaching the market. 

Bycatch also represents huge waste and a threat to the ecological sustainability of the global wild seafood supply. The United Nations Food and Agriculture Organization has stressed a need for nations to solve their bycatch problems and clean up the waste in fisheries.

“There is grave concern that excessive bycatch and discarding are still threatening the long-term sustainability of fisheries and the maintenance of biodiversity,” says Árni Mathiesen, assistant director-general, FAO Fisheries and Aquaculture Department, “resulting in increased food insecurity, and adversely affecting the livelihoods of millions of fishers and fishworkers dependent on fish resources.”

Mathiesen addressed an FAO meeting in Rome in December 2010, at which international guidelines on bycatch management and reduction of discards were adopted. The FAO estimated in 2004 that the discarded annual global catch was about 7 million metric tons and could be in excess of 20 million tons.

The more that fisheries address their bycatch issues, the better their chances of achieving sustainability certification, explains Mike Osmond, senior program officer at WWF’s fisheries program. And the more fisheries are certified sustainable, the greater the selection for seafood buyers — and the more sustainable the overall seafood supply, even though there is still a long way to go on the bycatch problem.

The WWF estimates bycatch related to marine capture fisheries includes more than 300,000 small whales, dolphins and porpoises that die from entanglement in fishing nets each year. Bycatch, says the conservation group, is the greatest killer of small marine mammals and has pushed several species toward extinction.

WWF encourages the solutions then follows them years into the future. “We also work with winning ideas to help advance them down the road to the ultimate goal of having them adopted by commercial fisheries,” says Osmond. “I feel we have a responsibility to help them as much as we can.”

In 2010, WWF worked with six past winners of its SmartGear competition to help the ideas gain traction. The grand prize winner of 2009 was the Underwater Baited Hook, a device positioned on the back of a longline boat that attaches bait to the line and distributes it far enough below the surface so that seabirds cannot reach the bait. The device addresses a major problem in tuna longline fishing, says Osmond: The incidental kill of albatross, which has endangered several species.

The Underwater Baited Hook — which was developed with the help of a seabird scientist — is being tested in the fishing grounds off Uruguay, the country with the highest seabird mortality associated with longline fishing. “They feel they can make it better,” says Osmond. “They’re working on it this year and there is still more work before it can be commercially manufactured.”

Studying fish behavior has also been helpful to development of the Nested Cylinder Bycatch Reduction Device (NCBRD) to decrease mortality of juvenile red snapper in the Gulf of Mexico shrimp fishery. This device is essentially two pipes, one 3 feet wide within another that is 5 feet wide. The arrangement of the two pipes creates an escape opening around the entire circumference of the net, according to a scientific paper about the device under review and written by Glenn Parsons, a biologist at the University of Mississippi and Daniel Foster, at the National Marine Fisheries Service (NMFS) in Pascagoula.

The dual-cylinder device also plays to species-specific behavior: Snapper tend to retreat to areas of quieter water, which increased their chances of escaping the trawl. At night, more snapper tended to escape when the pipes were lit. In testing so far, the NCBRD reduces total fish bycatch in the Gulf of Mexico shrimp trawl fishery by about 40 percent with almost zero shrimp loss, says Parsons. The work was funded by the Sam Walton Foundation and NMFS; it won $10,000 in the WWF competition in 2007.

Now, in New England, Knight, the net maker who helped design the Ruhle Trawl, and scientists at the University of Rhode Island are testing a next-generation net they hope will help New England groundfish harvesters meet their bycatch regulations in a new sector management scheme adopted last year.

The WWF prize money, says Knight, helped to reimburse the initial partners who had financed a lot of the research out of their own pockets. To develop and test the device, they received a $450,000 NMFS grant. But far more important than the money was the political clout that let the net designers push their congressional representatives in 2007 to urge NMFS to allow boats to tow the net and target haddock in otherwise closed areas.

“I still say to this day,” says Knight, “that if it hadn’t been for the WWF win, the federal government would still be dragging their feet over it.”


Contributing Editor Lisa Duchene lives in Bellefonte, Pa.

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