Evaluation of a topless bottom trawl design with a 160 foot headrope for fish capture, final report Final report: Evaluation of a topless bottom trawl design with a 160 foot headrope for fish capture

Previous work attempting to mitigate sea turtle interactions with a bottom trawl equipped with a turtle excluder device (TED) in the summer flounder fishery resulted in a significant loss of target species. A subsequent evaluation of a 109 ft headrope topless trawl in this fishery resulted in catch rates of the target species equivalent to a traditional trawl, but when that topless trawl was evaluated on its ability to reduce sea turtle capture rates, it proved ineffective. However, a modified 160 foot headrope topless trawl was successful at capturing less sea turtles. The goal of the project described herein was to evaluate the topless trawl design with a 160 foot headrope in terms of its ability to catch finfish. The purpose of this report is to present the methodology used, the data collected and a limited analysis of catch efficiency of the 160 foot headrope topless trawl design as compared to a traditional flounder trawl design. The results of this evaluation indicate that the 160 foot headrope topless trawl significantly reduced the catch of summer flounder and skates when compared to the traditional trawl. Two vessels carried out the evaluation, and the mean loss of catch by F/V Darana R was 51% for summer flounder and 48% for skates, the dominant bycatch. The mean loss of catch by the F/V Caitlin and Mairead was 74% for summer flounder, and 31% for skates. In general, the addition of floatation appeared to improve the catch retention, but there were an insufficient number of replicate trawls with the increased flotation to thoroughly evaluate this effect. 2013 NOAA NMFS Contract Number: EA 133F-10-SE-2491, Mod. 002 NMFS (National Marine Fisheries Service) NEFSC (Northeast Fisheries Science Center) Submitted https://doi.org/10.25923/3gng-2797 Public Domain 1862