[[wysiwyg_imageupload:165:]] The New England Aquarium collaborates with the Consortium
for Wildlife Bycatch Reduction to research and develop new
and innovative fishing devices and methods that reduce the
threat of bycatch to sea turtles, large whales, sharks and other
marine animals.
Gillnet Modifications
Gillnets are thought to account for the highest volume of total fisheries catch worldwide after trawl and seine fisheries. In addition, gillnets are the prevalent method of artisanal fishing throughout the world, often with annual catch volumes that, in many developing countries, exceed those produced by the commercial sector, and the resulting catch goes largely unreported. Gillnets likely result in more marine mammal bycatch than any other fishing method. Sea turtles are also caught in large numbers in gillnets, and are at a greater risk for death when caught in gillnets than in other fisheries.
Unlike the variety of bycatch mitigation techniques available for other fishing methods, few are applicable to gillnets, particularly for the developing world. The techniques that do exist are highly species- and fisheries-specific, and mitigate only a tiny portion of the global collateral mortality of marine organisms in gillnets. Thus, there is an urgent need to develop solutions to the problem of gillnet bycatch.
Stiff/Acoustically Reflective Gillnets
The New England Aquarium is working with an international team of researchers to conduct a multi-national research study to evaluate the use of stiff gillnets as a practical method for reducing non-target species bycatch in gillnet fisheries. In different field trials throughout the world, the efficacy of these nets has varied widely, significantly reducing bycatch in some areas while showing no effect at all in others.
Field trials have been conducted to test the effectiveness of standard gillnets, barium sulfate gillnets, and stiff nylon gillnets for retaining target catch and reducing bycatch of franciscana dolphins (Pontoporia blainvillei) in collaboration with artisanal gillnet fishermen from northeast Argentina and Praia Grande, Sao Paulo State, Brazil. Researchers found that neither increasing the flexural stiffness of the nylon twine or increasing the acoustic reflectivity with BaSO4 reduced bycatch rates.
Read the published report.