Developing a full-scale shaking codend to reduce the capture of small fish

Author:

Nguyen Vang Y.,Bayse Shannon M.ORCID,Cheng Zhaohai,Winger Paul D.,DeLouche Harold,Kebede Gebremeskel Eshetu,Legge George

Abstract

To reduce the retention of undersized fish in the redfish (Sebastes spp.) trawl fishery in the Gulf of St. Lawrence, Canada, we developed a full-scale shaking codend. The shaking codend uses a mechanical stimulating device, an elliptical-shaped piece of polyvinyl chloride canvas, attached to the posterior of a T90 codend that generates a lifting force with respect to drag, causing a ‘shaking motion’. A shaking codend could stimulate fish movement and increase contact probability, both of which could increase the escape of small redfish out of a codend, especially when combined with a codend that maintains mesh openings. The movement and fishing characteristics of a shaking codend (T90 codend with canvas) relative to a T90 codend (without canvas) were tested in a flume tank and field experiment. In the flume tank test, the shaking codend had a peak-to-peak amplitude (i.e. the distance the codend moves from the lowest to highest depth) > 24 cm higher than the T90 codend for each velocity tested (1.0–1.8 kt), higher amplitude ratio, and a higher period (1 revolution) that gradually decreased with increasing velocity. The total acceleration (m s-2) and drag forces (kgf) estimated for the shaking codend were significantly higher than the T90 codend across all flow velocities. The results from the field experiment, considered preliminary due to a small sample size, showed that the shaking codend significantly reduced the capture of small redfish (< 21 cm) and the best fit model did not need to consider contact probability which was necessary for the non-shaking T90 codend. Overall, the dynamics of the movement of the codend was described and could be potentially used as an effective technique to reduce the catch of small redfish, and perhaps in other trawl fisheries to reduce the catch of small fish.

Funder

Canada First Research Excellence Fund

Fisheries and Marine Institute

Publisher

Public Library of Science (PLoS)

Subject

Multidisciplinary

Reference61 articles.

1. Discards in the World’S Marine Fisheries.;K. Kelleher;An Update. FAO Fish Tech Pap,2005

2. Global marine fisheries discards: A synthesis of reconstructed data;D Zeller;Fish Fish,2018

3. A third assessment of global marine fisheries discards;MA Pérez Roda;FAO Fish Aquac Tech Pap,2019

4. Food and Agriculture Organization. The sunken billions: the economic justification for fisheries reform;World Bank;World Bank,2009

5. Fishery discards and bycatch: solutions for an ecosystem approach to fisheries management?;JM Bellido;Hydrobiol,2011

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