Quantification of gear inflicted damages on trawl-caught haddock in the Northeast Atlantic fishery

Manu Sistiaga,Bent Herrmann,Jesse Brinkhof,Roger B Larsen,Nadine Jacques,Juan Santos,Svein Helge Gjøsund

doi:10.1016/j.marpolbul.2020.111366

Abstract

External damages are indicators of the overall quality of fish and fish welfare. Haddock is an important commercial species widespread in the North Atlantic, but few studies related to quality have been carried out on this species. We studied the levels of external damages on haddock captured with a demersal trawl in the Northeast Atlantic. Further, we investigated to what extent the compulsory sorting grid and diamond mesh codend gear configuration employed in this trawl fishery is responsible for the external damages observed during the capture process. We evaluated external damages on 563 haddock captured over 22 hauls. In general, the results showed that catching haddock without any gear inflicted damages using demersal trawls is challenging. However, the results also showed that the severity of most damages is low and the probability to catch haddock with no external damage can be significantly increased removing the grid and changing codend design.

Highlights

Reducing external damages on fish can increase fishermen's revenue and make their limited fishing quotas more valuable
We investigated to what extent the compulsory sorting grid and diamond mesh codend gear configuration employed in this trawl fishery is responsible for the external damages observed during the capture process
The results showed that the probability to obtain haddock with no external damage of any type was 0.00% (0.00%–0.00%) with the grid and 130 mm diamond mesh codend configuration and 2.66% (0.39%–5.45%) with the gentle codend

Summary

Introduction

Reducing external damages on fish can increase fishermen's revenue and make their limited fishing quotas more valuable. Several of the studies carried out to evaluate the quality of gadoid fish caught with different types of trawls, have been carried out by evaluation of the external damages infringed during the capture process Digre et al, 2010; Brinkhof et al, 2018a, 2018b; Tveit et al, 2019) In these studies, the overall condition of fish was evaluated based on external damages such as gear marks, bruises and blood marks, improper bleeding, loss of scales and/

Objectives

Methods

Results

Conclusion