David Beutel, right, of the fisheries department at URI, is joined by, from left, fishermen Rufus Ayers and Ray Carr and captain Phil Ruhle Jr. aboard the Sea Breeze in 2005 as they prepare to test The Eliminator trawling net.

The Providence Journal / Bob Breidenbach

Three types of fish — cod, flounder and haddock — live together, swim together, eat together and are often caught together in commercial fishing trawlers.

Cod and flounder are heavily restricted by federal fisheries regulations, and fishermen often have to throw thousands of pounds back into the ocean — where they will likely die — because they were caught alongside haddock. And so fishermen often had to stop short of reaching their haddock quota.

But a team of researchers in Rhode Island has designed a net that effectively eliminates that problem. And yesterday they were awarded the $30,000 grand prize in the World Wildlife Federation’s International Smart Gear Competition for their efforts.

University of Rhode Island Fisheries Center researchers Laura Skrobe and David Beutel worked with fishermen Jon Knight, Phil Ruhle Sr., Phil Ruhle Jr., and Jim O’Grady on a net called The Eliminator, which takes advantage of haddock’s tendency to swim up when faced with a net, when other fish swim down.

The group received the reward yesterday in Washington. “We’re excited to be receiving this award,” Beutel said in a statement, “and look forward to continuing to research effective ways of reducing bycatch in fishing.”

The International Smart Gear competition was created to encourage engineers and fishermen to develop technologies that would reduce bycatch, or the unwanted part of a fishing catch, according to Ginette Hemley, the senior vice president of the World Wildlife Federation.

“Bycatch is a critical environmental and economic problem,” she said. “These inventions have shown to be effective solutions in our efforts to make fishing ‘smarter’ and we’re pleased to honor their creators today.”

The design, which beat out more than 70 contenders from 22 countries, is more than seven years in the making.

In 1999, Knight, who has fishing and engineering degrees from URI, began work on a net to help O’Grady and the Ruhles catch squid. It was designed with mesh larger than traditional trawler nets and did well with squid. But the fishermen also noticed that there were no cod or flounder showing up as bycatch.

Beutel and Skrobe placed an ad in trade publications and newspapers looking for help designing a selective net. Knight, O’Grady and the Ruhles answered.

The group put their heads together and used a lot of math and fishing trips to perfect the design: large, 8-foot mesh on the bottom of the net that cod and flounder can easily slip through, and smaller, 6-inch mesh on top and in the back to catch the haddock.

“The collaborative design and development of the Eliminator trawl is a great example of industry and scientists working together with managers,” Beutel said, “to develop innovative solutions to reduce or eliminate bycatch.”

bjeffers@projo.com