Using acoustically visible gillnets to reduce bycatch of a small cetacean: first pilot trials in a commercial fishery
Bycatch of protected species, particularly small cetaceans, in gillnets is a worldwide concern. One hypothesis for this is that echolocating cetaceans entangle because they do not perceive conventional gillnets as impenetrable barriers, owing to the gillnet’s faint echo. A gillnet modified for impro...
Published in: | Fisheries Research |
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Main Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2021
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Subjects: | |
Online Access: | https://orbit.dtu.dk/en/publications/cd569778-bec6-40a4-8ae9-5394700442a5 https://doi.org/10.1016/j.fishres.2021.106088 |
Summary: | Bycatch of protected species, particularly small cetaceans, in gillnets is a worldwide concern. One hypothesis for this is that echolocating cetaceans entangle because they do not perceive conventional gillnets as impenetrable barriers, owing to the gillnet’s faint echo. A gillnet modified for improved acoustical visibility was tested in a first pilot trial in a commercial gillnet fishery targeting turbot ( Scophthalmus maeoticus ) on the Turkish Black Sea coast. This study is the first demonstration of the viability of using a gillnet equipped with small acrylic glass spheres to reduce bycatch of harbor porpoises in a commercial fishery and provides the basis for full-scale sea trials of the gear in commercial fisheries through a power analysis. In these pilot experiments, the focus lied on the handling of the gear and identification of requirements for a full-scale trial, but results include promising bycatch data for an endangered echolocating marine mammal ( Phocoena phocoena ) and no reduction in catch efficiency of a bottom-dwelling, vulnerable species ( Raja clavata ). |
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