Serendipity is a common theme in science. Accidents and mistakes lead to fortuitous discovery; questions yield unexpected answers. For Steve Eayrs, a fish behavior and gear technology researcher at the Gulf of Maine Research Institute, surprise came about when a study about fishing gear selectivity found new ways for fishermen to save fuel and money, in addition to keeping more fish in the sea.
For the past few years, Eayrs has worked with groundfishermen in Port Clyde, Boothbay, Portland, and elsewhere in New England on gear-related issues. Gear research focuses on how to design and operate fishing vessels, nets, dredges, and lines in ways that reduce bycatch of non-target species and under- or over-sized target species.
“We got into this research to control catch composition and volume, but it ends up that a lot of this gear leads to better fuel economy as well,” said Eayrs.
With each fishing trip, fuel savings can be gained at various points, beginning with fishing vessel design and engine efficiency. Where and when people travel to fish are factors, as well as the kind of gear. Weight and resistance—when gear is in contact with the bottom, or fills up with fish—cause drag. The engine uses more fuel as it works harder against these forces.
“At this point, making money in groundfishing is all about the efficiency and business. Fishermen have some control over fuel use and small changes can have a positive impact on their businesses.” said Ben Martens, executive director of the Maine Coast Fishermens Association.”
“You can save up to 50 percent of what you spend on fuel by paying attention to your fuel usage and using gear that has less drag,” said Eayrs. As part of the project, Eayrs installed fuel-flow meters on the participating vessels. The meters act as a constant reminder to captains to watch how much fuel is being burned at any given time. “It raises my awareness of fuel,” said Travis Thorbjohnson, another fishermen participating in the research, “I see that when I ease back on the revs a little, I use less fuel but don’t lose speed. When I am towing for 24 hours, a little bit makes a difference.”
As part of the study, Thorbjohnson has been fishing with modified nets built with a thinner twine in an effort to catch fish more selectively and to reduce drag. (See, “Tank tests: fishing gear research goes hi-tech” May, 2010 and “Port Clyde fishermen test fishing gear that reduces by catch” February/March, 2009). He said he can’t detect a difference in the fish catch between the two nets, and has continued to fish with the modified net even after the scientific tests ended.
Jim Ford, a Massachusetts fisherman, tested another new form of gear known as semi-pelagic (or high aspect-ratio) trawl doors. Trawl doors keep a net open as it sweeps through the water, and are designed to eliminate bottom contact. During Ford’s test, the new doors reduced impacts to the sea floor while increasing fuel efficiency by about 12 percent with no loss of catch. If this figure holds up, Ford will see a return on his investment in about a year.
Another new piece of technology being tested is the use of cod-end sensors. The “cod end” is the sack at the end of the net that holds the captured fish. A sensor alarms when the cod end is full, alerting the fisherman to haul in his net. Fishermen report that the device can reduce haul duration by up to half, which means an equivalent fuel savings per haul.
In other efforts to reduce fuel costs, fishermen in Maine are studying the efficiency of their boats through the use of comprehensive energy audits. The auditors measured the hull, deck, rudder height, propeller diameter, engine room and other areas. The participating fishermen spent an hour or more answering questions to help provide data for the auditing process. The information from the interview and the measurements were then entered into a computer program that will produce a range of modifications to reduce fuel consumption and the payback period for each. Kelo Pinkham, whose boat, the F/V Jeanne C, was audited, is looking forward to getting the results. “When I have the report, I’ll know how to easily and cheaply reduce my fuel costs and what to prioritize when I haul my boat out for a major overhaul, I hope anyway” he said.
Eayrs has embraced the unexpected consequences of his research program, which has developed through a long-term partnership between GMRI, The Nature Conservancy, Island Institute, and the Maine Coast Fishermen’s Association.
“This research provides fishermen with more information they can use to manage their business. If every fisherman had catch sensors, a fuel flow-meter, smaller-diameter twine nets and semi-pelagic trawl doors, there would be a lot of fuel saved in the fleet and a better quality product as well,” said Eayrs. Fishermen are able to improve financial reward by fishing more selectively and with less environmental impact. Getting conservation and profitability intrinsically linked is a win-win for everybody.”
For more information on how to save fuel and improve fishing efficiency, visit
http://gmri.org/ar2010/science/science_spotlight_efficient_gear.html
http://www.islandinstitute.org/energyworkshops
This article is made possible in part by funds from Maine Sea Grant.
Nick Battista is the marine programs director at the Island Institute. Heather Deese holds a doctorate in oceanography and is the Island Institute’s vice-president of programs. Catherine Schmitt is communications coordinator for Maine Sea Grant.