All eyes focus on the aqua glow of the tank wall. The eerie blue light adds to the drama as we wait for the trawl to settle to the bottom of the flume tank.

The white net is framed at the leading edge by a stretch of grey ground-gear along the sweep-with rollers smaller than hockey pucks, and a series of white golf-ball sized floats along the head-rope.

The gentle flow of water through the tank carries the trawl backward as it settles, until it is stretched out just above the tank floor, in position. At that moment, the six fishermen in the room have their very first view of how their trawl gear looks as it traverses the seafloor.

Randy Cushman smiles. “That’s pretty much how I thought it looked,” he says, “or hoped anyway. Looks pretty good.”

The other fishermen in the group nod their heads, shift to get a better view, and study the look of the trawl they had been imagining for years. This view is possible because they are sitting in the observation gallery at the flume tank at Fisheries and Marine Institute of Memorial University of Newfoundland, in St. John’s.

The trip to the flume tank is part of a long process undertaken by Cushman and other fishermen, in partnership with Steve Eayrs of the Gulf of Maine Research Institute (GMRI), to develop and document improvements in fishing gear that minimize environmental impact and help preserve fish stocks.

This work has been part of a broader partnership between the Island Institute and local fishermen to secure access to sustainable, diversified fisheries along Maine’s coast. The partnership has led to creation of the Midcoast Fishermen’s Association and development of a revolutionary marketing and branding campaign for locally-caught fish-Port Clyde Fresh Catch, as well as research to document and continually improve environmentally-friendly fishing gear.

Randy Cushman, from Port Clyde, has been fishing the full-size version of the scale-model trawl we were looking at in the tank for almost 37 years. He received the gear dimensions from his father, and gradually shared them with others in his community.

He constantly tweaked the gear, adjusting lengths, weights and floats, all based on intuition. His vision of what the net looked like underwater is based on how the vessel responded while towing, what the net looked like once it was hauled back up, and what he caught. He has never seen how the trawl behaved after it went over his stern.

The pure enjoyment of the view doesn’t last long. Always looking for that extra bit of performance, the guys in the group start brainstorming. “Look how the top of the wings are bowed up.” “We could move weight further out the wings.” “Or move the floats in.” “Or change the set-back from the wires.”

So the team that runs the flume tank go to work making changes the fishermen suggest, and quantifying how those changes impact trawl spread, height, and drag.

The tank is the only one of its kind in North America, and one of only four in the world large enough to test trawl fishing gear, which is why six fishermen and three scientists made the journey by bus, plane and car from Maine to Newfoundland for a week of gear research.

Steve Eayrs from GMRI received funding from the National Fish and Wildlife Foundation for a gear research project in partnership with the Midcoast Fishermen’s Association. The purpose of the research, both in the flume tank and on boats in the Midcoast in 2009 and 2010, is to test the “standard Cushman trawl,” a net designed by Randy Cushman to target flatfish (flounders), and compare its performance to a “modified Cushman trawl,” made with thinner twine and larger mesh openings.

The modifications are aimed at decreasing unintentional catches of juvenile flounders and other species, while retaining larger marketable flounder and decreasing the total drag, and therefore the fuel required for fishing. Flume tank staff had painstakingly constructed two scale-model trawls, requiring over 80 hours of construction each, to Randy’s detailed specifications.

Along with Cushman, Travis Thorbjornson and Justin Libby, from Port Clyde, Tad Miller from Matinicus, Joe Nickerson, from Kennebunk, and Vincent Balzano, from Saco, are here for the week.

They find the facility impressive. The tank is almost 70 feet long, 25 feet across, and 13 feet deep, containing 1.7 million liters of water. The water velocity of up to one meter per second, translates to scaled tow speed, depending on the scale of the fishing gear. For this group, the focus was on trawl speeds of 2 to 3.5 knots. Side-view and top-view digital cameras measure trawl height and spread. Tension sensors quantify drag.

An hour later a full-suite of measurements on the standard Cushman trawl are complete, and we clamber up a metal spiral staircase to the second floor launching deck to change the set-back from the wires to the head-rope.

From the top, the flume tank looks like a swimming pool, but the walls are lined with boxes of scale-model trawls and miniature trawl doors, each about the size of the new iPad. Swimming in the tank is strictly forbidden, except on the rare occasion when gear needs to be recovered or maintenance performed on the giant electric impellers that circulate the water through the tank.

The next four days are spent analyzing how changes in the trawl arrangement influence trawl shape (spread, height) and drag, and comparing the standard and modified trawl. According to Eayrs, the results look promising. It will take a few months to complete analysis of the tank tests, but initial results indicate that the modified Cushman trawl (with thinner twine and larger mesh size) could produce 12-16 percent less drag than the standard trawl-dramatically increasing fuel-efficiency while fishing. Comparison of bycatch rates and retention of marketable fish in the standard and modified trawls will be completed through field tests this summer.

Back home after the trip, Cushman is thankful for the experience and looking forward to more research on the water this summer. “I’m already adjusting my gear based on what I saw up in the tank. That trip saved me months of experimenting on the water. And it was good to see how the gear really looks, after all these years.”

Heather Deese, Ph.D in oceanography, is the Island Institute’s director of marine programs. Deese made the trip as one of the scientists working on the project.