The Reduction of Butterfish and Scup Bycatch in the Inshore Loligo Squid Fishery

 

Funded by the Commercial Fisheries Research Foundation (SNECRI)

URI Investigator:  Laura Skrobe

Industry Principal Investigators: Christopher Brown & Steve Arnold

Scientific Investigator: David Beutel (Coastal Resources Management Center)

 

Project Summary 

This project is investigating the performance of an experimental trawl on its ability to reduce the catches of butterfish and scup in the Loligo squid fishery in Southern New England.  Initial testing of the experimental net was conducted at the flume tank facility at the Centre for Sustainable Aquatic Resources located at the Marine Institute of Memorial University of Newfoundland.  Industry participants, net builder, and research scientists involved in this study traveled to the flume tank with a model of the net to conduct the gear tests and make appropriate changes to the design before actual construction of the trawl. 

Side-by-side testing of the experimental trawl is being conducted using two commercial fishing vessels based in Point Judith, RI, comparing the experimental net to the control net.  The project is designed to investigate the quantity and catch composition of bycatch, particularly butterfish and scup, of the trawl nets.  Field tests were conducted in the fall of 2009 and will be conducted in the spring of 2010 in and around Block Island Sound and Rhode Island Sound.  A total of 10 days consisting of 6 tows of 45 to 60 minutes duration per day will be conducted.  The control net is a 362 x 12 cm two seam polyethylene balloon net equipped with a 20 cm (8 inch) rockhopper sweep.  The experimental net is identical to the control except for the addition of the eighteen foot long rope escape panel with the final two bellies repeated.  The rope escape panel will be fitted over the circumference of the original bellies 35.5 meshes down from the wide end of the 8 cm lower belly.  This will cause the original 8 cm bellies to act as a funnel.  Small canvas flow diverters will be used to maintain the shape of the after bellies, the escape panel, and the funnel.  Flow diverters also create small pockets of low pressure which may facilitate the butterfish and scup in finding the route of escape.  The investigators suspect that the butterfish and scup see and sense the escape panel after exiting the funnel.  The Loligo squid will not swim forward to the escape panel but the butterfish and scup will swim forward and escape.  Therefore, a bycatch reduction of butterfish and scup through the use of the experimental gear is anticipated. 

The basic impact of this research is to provide fishermen the ability to harvest Loligo squid without impacting regulated butterfish and scup stocks.  If these selective fishing practices yield the expected results, this gear would aid in the allowance for stock rebuilding of butterfish and scup while maintaining the Loligo squid harvest.  Ultimately, success of this project would lead to the incorporation of the experimental trawl into the fishery management plan and successful continuation of profitable fisheries.