Avoidance of Atlantic cod (Gadus morhua) with a topless trawl in the New England groundfish fishery

Published source details Eayrs S., Pol M., Caporossi S.T. & Bouchard C. (2017) Avoidance of Atlantic cod (Gadus morhua) with a topless trawl in the New England groundfish fishery. Fisheries Research, 185, 145-152.
Share Tweet Email

Actions

This study is summarised as evidence for the following.

	Action	Category
	Use a topless (coverless) trawl Action Link

Use a topless (coverless) trawl

A replicated, paired, controlled study in 2011 in bottom fishing grounds in the Gulf of Maine off Boston, USA (Eayrs et al. 2017) found that using a topless trawl reduced the unwanted catches of cod Gadus morhua in a mixed species bottom fishery, compared to a standard trawl. The catch rates of cod were lower with the topless trawl compared to the standard trawl (topless: 182 kg/hr, standard: 374 kg/h). In addition, catch rates were similar between trawl types for four of five species/species groups of commercial value: yellowtail flounder Limanda ferruginea (topless: 83 kg/h, standard: 82 kg/h), skates Rajidae (topless: 36 kg/h, standard: 32 kg/h), witch flounder Glyptocephalus cynoglossus (topless: 22 kg/h, standard: 25 kg/h) and spiny dogfish Squalus acanthias (topless: 22 kg/h, standard: 27 kg/h). Catches of long rough dab Hippoglossoides platessoides were lower in the topless trawl (topless: 36 kg/h, standard: 49 kg/h), however, the reduction was almost all undersized individuals (data reported as statistical result). Data were collected in May and June 2011 from 30 paired deployments on a commercial fishing vessel using the topless and standard trawl net designs towed in parallel (45 min, 2.6 kt). The headline length of the topless and standard trawls were 46 m and 21 m, respectively, and headline to footrope ratios were 1.7:1 and 0.8:1, respectively. See original paper for full gear specifications.

(Summarised by: Chris Barrett)