An overview on elasmobranch release as a bycatch mitigation strategy

Abstract

Sharks and rays are among the most threatened vertebrates, mostly due to commercial fisheries. Data on incidental capture is sparse, but it is estimated that about 50% of reported global catches of elasmobranchs are from bycatch. Elasmobranchs are captured in a variety of fishing gear throughout the world. One promising strategy to minimize incidental catches is the release of live sharks and rays. However, so far, no critical analysis had been carried out to assess the importance of release as a measure to mitigate the impacts of bycatch. Results indicated that despite onboard releases being cited in Plans of Action (along ZEEs) and recommendations/regulations of Regional Fisheries Management Commissions (in international waters), this measure is treated as secondary and has voluntary adherence, which can significantly reduce its efficiency. Moreover, among the Best Fishing Practice Manuals currently available, although release is cited as a priority, most of them do not consider the dynamics of the location/fishing modality for which it was developed. A change on how release is perceived is needed to prioritize this conservation strategy, as well as its potential as a social tool to reduce the impacts of bycatch on sharks and rays.

Drawing on local knowledge and attitudes for the conservation of critically endangered rhino rays in Goa, India

“…While avoidance of capture would be ideal to conserve threatened bycatch species (Milner‐Gulland et al, 2018), it would be challenging here due to the relatively low selectivity of gear and shared habitats with target species. Release can be an effective and low‐cost conservation measure in tropical, mixed species fisheries, especially when measures like spatial closures or gear modifications are not feasible (Gupta et al, 2020; Wosnick et al, 2022). Although poorly studied, some studies have noted moderate to high survival rates post‐capture for different rhino ray species (Fennessy, 1994; Prado et al, 2021; Stobutzki et al, 2002); high survival has also been observed by fishers in our study site.…”

Dual‐method survey of recreational fishing for guitarfishes in Southern and Southeastern Brazil

“…Catch‐and‐release guidelines should be developed in collaboration with specialists and rely on participation by recreational fishers to draw on their substantial knowledge regarding capture techniques, injuries observed, mortality incidents, and other insights (Brownscombe et al., 2017). Guidelines should prioritize simplicity, clarity, and visual aids to effectively convey best practices and discourage harmful methods (Wosnick et al., 2023). Moreover, an identification guide for guitarfishes in the Pseudobatos genus is needed, in straightforward language with easily recognizable features (Leite, 2022).…”