Simple gear modifications for achieving greater than 40% bycatch reduction in an estuarine shrimp trawl fishery

Abstract

Penaeid shrimp fisheries, particularly those operating with bottom otter trawls, can generate high levels of bycatch. In 2014, a workgroup was formed to devise and test gear modifications in Pamlico Sound and the near-shore waters of North Carolina with the goal of improving bycatch reduction rates. Trials were conducted in 2015 and 2016 on large (>12 m), double-rigged industry vessels, and trials were conducted in 2017 on 1 double-rigged vessel and 3 smaller, twin-rigged vessels. A paired t-test and a randomization test were used to compare tows. The results of both tests indicate that 4 of the 14 gears tested achieved an average rate of finfish bycatch reduction that was 40% greater than that of the control gear. Shrimp loss in most gears tested was minimal. Three of the 4 gears that met the reduction goal for finfish bycatch employed a combination of increased codend mesh size and larger finfish escape openings relative to the control configuration. Relying on industry input and expert opinions as well as on past research to guide the selection of test gears and their design, the workshop members developed gear combinations that appear to meet the management objective for bycatch reduction. The results of this work provide direction for future testing in similar fisheries.