A team of scientists and fishermen led by the Gulf of Maine Research Institute has created a new kind of fishing net that can catch popular flatfish like yellowtail flounder without busting strict quotas set to protect the Atlantic cod from overfishing.

The new design shrinks the height of this cone-shaped, bottom-dragged net from 5 or 6 feet to about 2, and cuts away much of the top, allowing about half of the cod that would be caught in a traditional trawl to swim to freedom over the top of the smaller, cut-away net.

The ultra low-opening trawl net, seen in the water recirculating tank at the Marine Institute of Newfoundland. The headrope is longer than the groundgear, or sweep. Usually, the headrope is shorter than the sweep. The design enables cod to swim up and over the net, escaping capture, while bottom fish like the flounder are caught. Photo courtesy of Gulf of Maine Research Institute

Field tests show that the ultra low-opening trawl reduced the amount of cod caught by about 45 percent, but landed just as many flatfish, like yellowtail or dabs, as a traditional net dragged over the same area by the same fisherman, said research scientist Steve Eayrs, who joined the Gulf of Maine Research Institute in 2007 to head up its efforts to develop environmentally friendly fishing gear. It also reduced fuel consumption by about 7 percent.

“For the first time, fishermen in New England have to avoid cod as best they can, which is a reversal of 400 years worth of tradition,” Eayrs said. “Yet here we are, having some very good success pretty much straight off the bat. In effect, fishermen can fish almost twice as long using this trawl without being limited by their cod quota or losing other valuable fish.”

Catching the wrong fish, or catching too much of a low-quota fish like cod, can end a season for a commercial fisherman. In recent years, the interstate New England Fishery Management Council has slashed the number of cod that can be landed from the Gulf of Maine from about 1,550 metric tons in 2014 to 280 metric tons now. Fishermen who catch too many, even by accident, can be shut down for the season.

Regulators are trying various methods, including quotas, trip limits and gear restrictions, to help fishermen catch the right fish and avoid what’s known as bycatch, which can lead to overfishing low-quota species like cod or the discard of food fish such as haddock. The industry is trying to modify gear and techniques to better target some species while avoiding others to avoid burdensome quotas or closures.

Fishermen who trawl for herring off Georges Bank cited their fear of haddock bycatch – at certain times of the year, schools of haddock and herring swim together, making it hard for herring trawlers to avoid haddock, which is not a vulnerable species but an economically important one with its own markets, fleet and quotas – as a reason they didn’t land enough of the popular baitfish to supply Maine’s $500 million annual lobster industry.

Atlantic cod and the flounder family are considered groundfish, and Maine’s once sizable groundfish fleet has practically disappeared, falling from more than 300 boats in 1982 to about 50 today. In 2015, all the groundfish landed in Maine totaled less than 5 million pounds, and was valued at about $7.1 million, which is a little more than 1 percent of Maine’s total 2015 catch of all species, according to state data.

Researchers, fishermen and gear manufacturers would like to find a way to bring back Maine’s storied groundfishing fleet.

The ultra low-opening trawl test results bode well for future collaborations among fishermen, scientists and gear manufacturers to develop new ways to protect vulnerable fish without killing off the fisherman’s livelihood, reducing the availability of the flounder that remain both plentiful and popular with the consumer, or taking a bite out of an iconic sector of the New England economy.

The net redesign team was led by Eayrs, himself a former commercial fisherman in Australia, and Massachusetts state fisheries biologist Michael Pol. The team included four commercial fishermen from Massachusetts and New Hampshire, two other scientists and a Rhode Island netmaker. The National Oceanic and Atmospheric Administration’s Saltonstall-Kennedy program funded the $265,000 project in 2015, when it awarded $22 million in fisheries grants.

Gulf of Maine Research Institute scientist Steve Eayrs samples the catch landed aboard the Lisa Ann III. The new net caught as much flatfish as a traditional trawl, but cut the number of cod caught in half and vessel fuel use by 7 percent. Photo courtesy of Gulf of Maine Research Institute

NEW MODEL FOR TRADITIONAL INDUSTRY

Over the course of a year, the team came up with several prototype trawls intended to avoid cod, but chose this low-opening design for computer modeling, then a scale model of the same net for testing in a large recirculating water tank at the Marine Institute in Newfoundland. Based on those results, they commissioned the net maker to build a full-scale trawl for field tests.

Massachusetts fishing captain Jim Ford tested the low-opening net, alternately dragging it and a traditional trawl behind his boat, the Lisa Ann III, for two weeks in May just east of Newburyport. Ford liked the net enough to ask to keep it for his own use for the rest of the fishing season. Eayrs hopes he will tell his friends all about it.

The netmaker is building three more ultra low-opening nets that will be available for loan to Gulf of Maine fishermen at no cost in 2017.

“We only ask that fishermen share the landing and fuel results with the team,” Eayrs said.

If the fishermen like it, Eayrs is hopeful they will order nets like it from their net makers when it is time to replace their traditional trawl nets. The average trawl net usually has a lifespan of about five years for a typical fisherman, unless it becomes snagged on something when dragging the flat ocean bed and rips, Eayrs said. That means widespread change to this net would take time, and only happen if fishermen want it.

Although they have sometimes used gear restrictions to protect species, Eayrs said regulators would be unlikely to ever require flounder fishermen to use this new kind of net, because it would be considered redundant when cod is already managed by a strict quota system. Both regulators and researchers want fishermen to embrace a cod-aversion net like this one on their own rather than have it forced on them.

While fishermen are reluctant to invest in new technology, the savings promised by the new net is persuasive, Eayrs said. Not only is it cheaper, costing between $8,000 and $10,000 compared to the average $10,000 to $12,000 cost of a similarly sized traditional trawl, and easier on a fisherman’s gas budget, but the cod reduction means a fisherman can land more flounder without having to worry about buying extra cod quota.

“With numbers like that, we think the idea will catch on,” Eayrs said.