Discard mitigation increases skate survival in the Bristol Channel

Enever, R., Revill, A. S., Caslake, R. and Grant, A. ORCID: https://orcid.org/0000-0002-1147-2375 (2010) Discard mitigation increases skate survival in the Bristol Channel. Fisheries Research, 102 (1-2). pp. 9-15.

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The survival of fish discarded after being caught can be improved by simple gear-based technical measures aimed at reducing discards. We look at the effects of three different codends on the initial health and short-term survival of trawl-caught skate (Rajidae), using a control codend (80 mm diamond mesh used as standard in the fishery) and two experimental codends (100 mm diamond mesh and 100 mm diamond mesh turned on the square). Both experimental nets reduced discarded numbers of fish by ~70%, with no commercial loss. This reduction in discards had an effect in reducing the total weight of the experimental codends by as much as 80%. We also placed 278 skate in onboard holding tanks for 48 h and evaluated the survival rates of fish caught in the different codends. Visual inspection of "health" at time zero was a good indicator of survival, because 86% of skate with a good health score survived (p < 0.01). From a further 1539 skate assessed for health, we show that fish caught in the control codend have the lowest proportional good health score (25%), followed by the 100 mm diamond mesh codend (34%) and the 100 mm square mesh codend (47%). The health of the fish caught is related to codend weight (p = 0.01). We conclude that technical measures aimed at reducing discards have an additional benefit; they indirectly increase discard survival, and the benefits of mitigating discards through by-catch reduction devices may be a more powerful tool in fisheries management than previously thought.

Item Type: Article
Faculty \ School: Faculty of Science > School of Environmental Sciences
UEA Research Groups: Faculty of Science > Research Centres > Centre for Ecology, Evolution and Conservation
Faculty of Science > Research Groups > Environmental Biology
Faculty of Science > Research Groups > Centre for Ocean and Atmospheric Sciences
Faculty of Science > Research Groups > Resources, Sustainability and Governance (former - to 2018)
Faculty of Science > Research Groups > Marine and Atmospheric Sciences (former - to 2017)
Depositing User: Rosie Cullington
Date Deposited: 02 Feb 2011 15:52
Last Modified: 12 Jan 2024 01:21
URI: https://ueaeprints.uea.ac.uk/id/eprint/20277
DOI: 10.1016/j.fishres.2009.09.013

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