Quantifying habitat preference of bottom trawling gear

N T Hintzen,A D Rijnsdorp,J J Poos,K J Van Der Reijden,G Aarts,Finbarr O’Neill

doi:10.1093/icesjms/fsaa207

Abstract

Abstract Continental shelves around the world are subject to intensive bottom trawling. Demersal fish assemblages inhabiting these shelves account for one-fourth of landed wild marine species. Increasing spatial claims for nature protection and wind farm energy suppresses, however, the area available to fisheries. In this marine spatial planning discussion, it is essential to understand what defines suitable fishing grounds for bottom trawlers. We developed a statistical methodology to study the habitat preference of a fishery, accounting for spatial correlation naturally present in fisheries data using high-resolution location data of fishing vessels and environmental variables. We focused on two types of beam trawls to target sole using mechanical or electrical stimulation. Although results indicated only subtle differences in habitat preference between the two gear types, a clear difference in spatial distribution of the two gears was predicted. We argue that this change is driven by both changes in habitat preference as well as a change in target species distribution. We discuss modelling of fisheries’ habitat preference in light of marine spatial planning and as support in benthic impact assessments.

Highlights

Continental shelves around the world are subject to intensive bottom trawling
We argue that there is a clear role for habitat preference modelling in spatial fisheries management, such as tailoring the design of marine protected areas and supporting benthic impact assessments
We study the Dutch beam trawl fleet targeting mainly sole in the southern North Sea

Summary

Introduction

Continental shelves around the world are subject to intensive bottom trawling. Demersal fish assemblages inhabiting these shelves account for one-fourth of landed wild marine species (Amoroso et al, 2018). Beyond spatial planning, discussing the footprint of bottom fishing and comparing the impacts different types of fisheries have on seafloor integrity have increased in attention in recent years This is likely driven by the Marine Strategy Framework Directive (MFSD) (EC, 2008) prescribing that member states in the EU need to ensure that seafloor integrity is at a level that ensures functioning of the ecosystem (Descriptor 6). The societal debate focusses on the ratio between seafloor impact (i.e. area impacted by a bottom trawl gear measured in km2) and the amount of animal proteins obtained in the fishing activity, VC International Council for the Exploration of the Sea 2020.

Methods

Results

Conclusion