Nets that will keep targeted species and allow others to escape have long been the goal of fishermen and researchers trying to solve the thorny and wasteful problem of bycatch. But now the pressure is even greater, as New England fishermen desperately try to survive crushing regulations.

Selective gear may not be a “silver bullet” that can save harvesters in the current situation, but some researchers say improved net designs might help now, and will certainly make a big difference in the future.

“The potential short-term benefit is a design which will look beneficial to the judge or National Marine Fisheries Service or whoever makes the decision,” said Mike Pol, marine biologist with the Massachusetts Department of Marine Fisheries (DMF). “The question is, how much proof is enough?”

“A net can work fine on one vessel, but you can put it on another vessel and it behaves totally differently,” said Pol. “We call it `boat effect.'” The scientist believes selective nets will eventually become the norm, but testing and approval of new devices can take years. A small-mesh whiting net used by Cape Cod fishermen took five years to gain approval.

New England groundfishermen don’t have five years.

Several designs for nets that will allow cod to escape while keeping other species such as flatfish are currently being tested by the DMF on fishing vessels out of Provincetown and Gloucester. In January, six New England fishermen went to Newfoundland with Pol and other researchers to test selective net designs at the Memorial University Flume Tank in St. John’s.

“We have to make nets that eliminate or minimize bycatch,” said Proctor Wells of Phippsburg, Maine, one the fishermen who went to the Flume Tank. Wells catches groundfish, lobster and shrimp from his 46-foot trawler, TENACIOUS.

“Restrictions don’t work any more,” said Luis Ribas, Provincetown fisherman. “They only work to put fishermen out of business.”

“We have huge issues to overcome,” said Wells recently. “If we had more selective gear available, we wouldn’t have been in the position we were” when environmentalists sued the federal government for failing to protect groundfish stocks and won.

Several of the fishermen who brought their experimental selective gear to Newfoundland for testing put their theories into practice at home this spring. Their designs include “low riders,” “topless” and “sweepless” trawls they hope will help. The gear-testing project was led by Arne Carr, recently retired senior fisheries biologist with the Massachusetts DMF Conservation Engineering Program.

Carr hand-selected the fishermen he invited to attend, choosing people he had met during the course of his work who expressed a strong interest in net design. Several were already working on designs or modifications.

“I went to Gloucester to see Joe Scola and I ran into Danny Murphy. He started talking about his net idea, and I immediately tagged him for the workshop,” said Carr. Murphy, of Dracut, Mass., tested a net extension that adds “fish eyes” or holes in the net to allow cod to escape, but keep flatfish. The DMF is interested in Murphy’s idea to reduce scup bycatch in the squid fishery south of Cape Cod.

Scola’s “low riser,” another cod-reducing design, involved setting the headrope low and forward of the footrope. At the tank, Ribas and Scola ended up helping each other modify nets. In late April, Scola tested his net while fishing from his home port in Gloucester, using a video camera to watch the fish behavior and net action.

Ribas previously worked with a DMF net to allow cod to escape while keeping flatfish. The “topless” trawl allowed 96 percent of cod to escape, but the net also allowed yellowtail flounder to go free. At the tank, Ribas modified the DMF net to add 8-inch mesh on the top to try to retain the yellowtail. Tank tests showed the net wingends curled over. Observers thought the collapse might direct yellowtail out of the net.

The “Ribas net” uses square mesh, 6 inches and up, Ribas said, “because we have problems here with codfish and using square mesh catches more flatfish and less codfish.” He believes the current rules mandating six-and-a-half-inch mesh but not requiring mesh to be square won’t make much difference in saving cod. His tests aboard his 62-foot trawler BLUE SKIES show the Ribas net allows 70 to 90 percent of cod to escape, but it also allows around 20 percent of the flatfish to escape.

“It needs more modification to keep more flatfish,” said Ribas. “But it allows all the juvenile fish to escape. It only catches big fish.”

“It would be nice if we had something in place, but it’s a slow process,” said Pol. “Now people can’t go fishing because of cod. If we could keep the cod out… it has great potential.” A Massachusetts budget shortfall has curtailed efforts to expand the project for now. However, when the DMF’s experimental fishing permit is extended, Pol will continue net trials using two Ribas vessels and Scola’s DOLORES LOUISE.