Individual study: Reducing bycatch in beam trawls and electrotrawls with (electrified) benthos release panels
Soetaert M., Lenoir H. & Verschueren B. (2016) Reducing bycatch in beam trawls and electrotrawls with (electrified) benthos release panels. ICES Journal of Marine Science: Journal du Conseil, 73, 2370-2379
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Fit one or more mesh escape panels/windows to trawl nets
A replicated, paired, controlled study in 2014–2015 in five seabed areas in the North Sea, UK and Belgium (Soetaert et al. 2016) found that overall, when fitted to trawl nets, all four designs of square-meshed window (“bycatch reduction device”) tested reduced the non-commercial unwanted catch of invertebrates (discard), compared to unmodified nets without a device. Fitting nets with either design (window of either 150 mm, 200 mm, 240 mm mesh, or a 240 mm window with electrical pulse; see paper for details) decreased the catch of all invertebrate discard species recorded by 9–100% compared to unmodified nets. The 150 mm window significantly decreased catches of 11 of 15 species (55–91% reduction). The 200 mm window significantly decreased catches of 10 of 14 species (9–92% reduction). The 240 mm window significantly decreased catches of nine of 18 species (38–97% reduction). The electrified 240 mm window significantly decreased catches of 15 of 19 species (58–100% reduction). All devices reduced catches of commercially targeted species compared to nets without a device, by between 5 and 22%. Invertebrate discard was compared in nets with and without a device. Nets were deployed by two vessels during 58 paired hauls for 1.5 hour (one net with and one without a device; 10–22 hauls/device type). All invertebrate discards were identified, counted, and weighed from 5–8 kg subsamples. Commercially targeted catches were weighed. No comparisons were made between windows of different designs.
(Summarised by Anaëlle Lemasson & Laura Pettit)