Gut content metabarcoding reveals potential importance of fisheries discards consumption in marine fauna
|Lejeune Benjamin1, 2, Mouchet Maud Aline1, Mehault Sonia2, Kopp Dorothee2
|1 : Centre d’Ecologie et des Sciences de la Conservation, UMR 7204 CNRS-MNHN-UPMC, 43 rue Buffon, CP 135, Paris 75005, France
2 : Ifremer, Unité de Sciences et Technologies Halieutiques, Laboratoire de Technologie et Biologie Halieutique, 8 rue François Toullec, Lorient F-56100, France
|Canadian Journal Of Fisheries And Aquatic Sciences (0706-652X) (Canadian Science Publishing), 2022-07 , Vol. 79 , N. 7 , P. 1064-1073
|WOS© Times Cited
Fisheries discards have become a source of concern for the perennation of marine resources. To reduce discards, the European Union adopted a Landing Obligation under the reform of its Common Fisheries Policy. However, food web consequences of reducing discards remain uncertain since their degree and pathway of reintegration are understudied. We used multi-marker DNA metabarcoding of gut contents and an ecological network approach to quantify marine fauna reliance on discarded fish and functional importance of discard consumers in coastal fishing grounds. We show that potential discard consumption is widespread across fish and invertebrates, but particularly important for decapods which were also pinpointed as functionally important. Potential discard consumption may represent up to 66% of all interactions involving fish prey in the reconstructed network. We highlight that discard reliance may be more important than previously assessed in some fishing areas and support functionally important taxa. While reducing discarding remains a conservation priority, it is crucial to understand discards reintegration in marine food webs to anticipate changes in the context of an ecosystem approach to fisheries management.