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Feature Articles
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NE fishermen, scientists test trawl ideas
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This article is reprinted with permission of Commercial Fisheries News, the Northeast's fishing newspaper for over 30 years, ©2003 Compass Publications Inc. Commercial Fisheries News is published monthly; annual subscriptions are $21.95. To subscribe or request a sample issue: call (877) 263-4496; fax (207) 367-2490; e-mail (cfoster@fish-news.com); or click on the hot link.
By Wendy Anne La Voie
In the February 2002 issue of CFN, we featured a story about a cooperative research project in which eight New Hampshire fishermen traveled to the famous Memorial University flume tank in St. John's, Newfoundland to learn about the potential for gear selectivity to reduce unwanted bycatch.
This month, we have a story about another group of fishermen who went to the flume tank to actually test out their experimental trawls and get a firsthand look at what's working and what needs to be fixed. --Editor
Quick Links:
Scola net: 'Low-rider' rising to the occasion
Murphy project: Using 'fish eyes' to free cod
Ribas project: Flatness net goes 'topless'
Who's who: Participants at flume tank project
ST. JOHN'S, NEWFOUNDLAND - January may not be the best month to travel to Canada, but the cold didn't stop a unique team of 15 New England fishermen, scientists, and gear technology experts from heading north Jan. 15-19 for a trawl gear testing cooperative research project.
Inside the Center for Sustainable Aquatic Resources (CSAR) located at the Fisheries and Marine Institute of the Memorial University of Newfoundland, it was warm, inviting, and the research team ignited the atmosphere with collaborative ideas and fresh perspectives for improving fish harvesting technology.
CSAR is home of the famous Canadian flume tank. The facility is unique in that it is the only operator-controlled water velocity and seabed velocity flume tank in North America.
Arne Carr, senior fisheries biologist with the Massachusetts Division of Marine Fisheries (DMF) Conservation Engineering Program, orchestrated the gear-testing and evaluation project with funding from the Northeast Consortium.
Other participating scientists included Chris Glass of the Manomet Center for Conservation Services (MCCS), Dan Schick of the Maine Department of Marine Resources (DMR), and other biologists and technicians from DMF and MCCS. Six fishermen from Maine, Massachusetts, and Rhode Island, as well as a Rhode Island net maker, also participated (see complete list in box below).
Project goals
The project had three primary goals: to test fishermen's bycatch reduction methods through scale models of their gear designs; to test, evaluate, and improve gear already in use; and to test specific gear, such as codend covers, used in research and commercial gear development.
But this was only the tip of the iceberg. Another important goal of organizers in bringing the diverse group together was to open up and strengthen lines of communication between fishermen, scientists, and gear technologists.
"I think the trip was an excellent shot in the arm for conservation engineering," said Gregg Morris of MCCS.
"Fishermen went away from this trip with a better understanding of gear and also of the people who are working with them, such as DMF and Manomet, to try to find answers to problems regarding bycatch and towed fishing gear," he said.
Maine fishermen Vincent Balzano, left, and Proctor Wells sew a net model that will be tested in the flume tank. MA DMF photo.
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Flume tank
The flume tank allows observers to see how gear behaves under different towing conditions and how some static gear behaves under controlled conditions.
The fishermen and scientists were able to watch the gear in the tank as adjustments were made to the velocity of the water flow and the "floor" speed.
When they saw problems, they could haul out the gear, adjust it, and set it out again. The gear was measured optically and then, using the facility's computer software, scaled up to show the impact of any adjustments on the gear at full-scale.
"As a trawl gear designer/maker, the chance to see working models in the flume tank was invaluable," said Mary O'Rourke of Trawlworks Inc. in Narragansett, RI, one of the leading net manufacturers in the region.
Glass, Morris, and Tim Feehan, also of the Manomet Center for Conservation Sciences, brought along codends and extensions to test in the flume tank.
They experimented with different types of mesh, including square mesh, diamond mesh, and hexagonal mesh. They also tried out an experimental extension piece, which included a composite codend consisting of square and diamond mesh.
The scientists also tested a codend cover with and without floats and hoops to determine the most efficient way to rig it so that it didn't mask the webbing of the inner codend.
While the fishermen who tested trawls had to use scale models of their nets, the flume tank was large enough to accommodate full-scale versions of these codends and extensions.
From left, Tim Feehan of the Manomet Center for Conservation Sciences, Phippsburg, ME fisherman Proctor Wells, and Dan Schick of the Maine Department of Marine Resources sew a net onto a ring for flume tank testing. MA DMF photo.
Getting to know you
As advantageous as it was to test several different types of net configurations, as well as models in order to help stimulate ideas for current and future projects, the talking that went on among participants over the week-long project was, perhaps, the best thing of all.
The project involved a surprising mix of people. Fishermen from different areas, armed with innovative ideas, along with scientists ready to roll up their sleeves, came to the tank to solve gear problems and to make suggestions for solutions.
At first there was some apprehension about telling "another fisherman how to do his job." But once everyone got through this initial icebreaker and realized that this exchange of ideas was the meat of the program, they all put in their two cents and lent a hand at making the necessary modifications.
For example, fisherman Joe Scola of Gloucester started out working alone to make adjustments to his "low-rider" net when he soon found himself joined by his peers.
"I was amused and happy to see everyone pitch in to help Joe adjust his scaled-down net," said Carr, "Joe started almost alone. Then you saw Luis (Ribas), Scott (Westcott), and Mary next to him looking on and giving advice. It was just the dialogue and activity we were hoping to see here in this setting."
Each team of researchers was interchanged throughout the duration of the trip. Everyone pitched in on everyone else's projects. All of the fishermen went away from the experience ready to modify their own gear armed with these newly shared ideas, as well as the concrete data obtained through the CSAR's computer calculations.
There were also many discussions centered around gear technology, fisheries management, fisheries management politics, conservation and harvesting techniques, and other issues and ideas related to fish behavior and towed trawl gear.
From left, Provincetown, MA fisherman Luis Ribas, Arne Carr of DMF's Conservation Engineering Program, and Chris Glass of Manomet Center for Conservation Sciences observe the performance of a net model in the flume tank. MA DMF photo.
Kudos to staff
The facility and staff at CSAR -- including hosts Glenn Blackwood, Harold DeLouche, Phil Walsh, and George Legge -- earned kudos from all of the participants in the week-long project.
"The openness on the part of the staff to share their expertise on trawls really impressed me," said Phippsburg, ME fisherman Proctor Wells. "They are in my mind world class. They have an incredible facility."
Fisherman Dan Murphy of Dracut, MA added, "The educators at the institute cared about our interests and were willing to cater to all of our needs. The institute made me feel very welcomed and I am looking forward to coming back."
Future implications
In a look towards the future, fishermen and scientists know they need to develop trawls that are "bottom friendly" and have little if any bycatch.
The work that has been done through cooperative research is beginning to address these needs. Further experimentation to develop trawls with no bycatch or trawls that retain only the size and species of wanted fish can and should be experienced by other fishermen, scientists, fisheries managers, and conservationists.
The positive reaction to the project by participants can be summed up in these words from Portland, ME fisherman Vincent Balzano.
"I had great joy watching the fishermen take a proactive approach rather than a reactive one," he said. "After a lifetime in the fishing industry, that was the most positive and enjoyable time I have ever had with fishermen. Then you throw in scientists and state (biologists) and that's just historical."
Wendy Anne La Voie is a freelance writer who resides in Massachusetts.
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Scola net: 'Low-rider' rising to the occasion
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Joe Scola of Gloucester, MA has been working on his own design of a trawl that reduces cod and has built a net that he fishes on his boat. Called the "low-rider," Scola's net design involves setting the headrope low and forward of the footrope.
While a scale model was used in the flume tank testing, the full-size low-rider rises off the ground by only 3'-4'. Scola's idea is to have the net fish as low as possible, under schools of cod.
The only problem observed with this net design was with the wingends, which fluttered in the tank.
Joe Scola of Gloucester, MA worked on adjustments to the scale model of his "low-rider" net, in the flume tank, above, which he uses to catch flatfish and avoid cod. In the top image, Scola, left, and Wakefield, RI fisherman Scott Westcott lower the net into the flume tank.
After a few modifications, Scola ultimately removed excess twine and webbing from the wingends. After this adjustment, the net appeared tighter in the tank even under a variety of towing speeds.
Scola was not completely satisfied with the findings and the appearance of the net and would like to have spent more time at the facility perfecting his calculations.
"If I had a week in this tank, I know I'd get it right," Scola said during the workshop.
He, as well as the others present, felt that the experience was a great opportunity to learn from the other fishermen, the university staff, and the scientists.
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Ribas project: Flatfish net goes 'topless'
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Luis Ribas of Provincetown, MA made a model of the Massachusetts Division of Marine Fisheries (DMF) "topless" flatfish trawl, which field testing has demonstrated releases up to 96% of the cod it catches. The problem is that yellowtail escape, too.
Last year, Ribas worked closely with DMF on two nets designed to retain flatfish and release cod: his own design, the Ribas net, which uses a minimum of 8" mesh laid on the square on the top; and the DMF topless net.
The topless design sets the headrope far behind the footrope. This allows codfish to go up and over the nets and escape while retaining the flatfish.
During at-sea trials, however, the net retained fewer yellowtail flounder compared to the standard net. So, Ribas scaled down the model of the topless net in order to see how the net behaved in the flume tank under a variety of speeds and conditions.
The flume testing demonstrated that the wingends of the trawl were curling over. The research team surmised that this outward collapse could actually direct yellowtail out of the net.
Ribas was able to make some adjustments to the bridles, but that seemed to have little effect. The final adjustment involved connecting the two wings by rope. The connection was made on the headrope halfway back from the wingends to the belly.
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Who's who: Participants at flume tank project
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Arne Carr, senior fisheries biologist with the Massachusetts Division of Marine Fisheries (DMF) Conservation Engineering Program, arranged the evaluation and gear-testing project for a team of 15 New England partipants at the Canadian flume tank. The tank is part of the Center for Sustainable Aquatic Resources (CSAR), which is located at the Fisheries and Marine Institute of the Memorial University of Newfoundland, in St. John's, Newfoundland.
In addition to Carr, other participating scientists included:
- Chris Glass of the Manomet Center for Conservation Services (MCCS);
- Dan Schick of the Maine Department of Marine Resources (DMR);
- DMF biologists Mike Pol, Mark Szymanski, and Vincent Manfredi; and
- MCCS gear conservationists Tim Feehan and Gregg Morris.
The DMF Conservation Engineering Program invited six fishermen from Maine, New Hampshire, Massachusetts, and Rhode Island to participate in a cooperative research project to test certain gear designs and ideas in the flume tank. Participating fishermen were:
- Dan Murphy, Dracut, MA;
- Vincent Balzano, Portland, ME;
- Luis Ribas, Provincetown, MA;
- Scott Westcott, Wakefield, RI;
- Joe Scola, Gloucester, MA; and
- Proctor Wells, Phippsburg, ME.
Also taking part in the project was net maker Mary O'Rourke of Trawlworks Inc. in Narragansett, RI.
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