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Is It Possible to Avoid Deep Sea Sharks in the Azores?

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Is It Possible to Avoid Deep Sea Sharks in the Azores? Is it possible to avoid deep-water sharks in the Azores hook-and-line fisheries? ©Jorge Fontes ©Jorge L. Fauconnet, D. Das, D. Catarino, E. Giacomello, J. Fontes, T. Morato, P. Afonso DiscardLess Science-Policy conference, Copenhagen, 30/01/2019 "This work has received funding from the European Union’s Horizon 2020 research and innovation programme under Grant Agreement DiscardLess No 633680” Who are the deep-water sharks? = those whose distribution is below 200 m Conservation issue + socio-economic 10 Bottom longlines Other species (n=4+) 5 Deania calcea Etmopterus spinax no. of species no. Hexanchus griseus 0 Deania profundorum 5_LC 1_CR 4_NT 2_EN 3_VU 7_NA 6_DD Dalatias licha Centrophorus granulosus Centrophorus squamosus 0 20 40 60 80 Catch (t/year) average 2000-2014 TAC 0 species Objectives How can deep-water sharks be avoided? What can be done for those than cannot be Fontes ©Jorge avoided? TACTICAL & TECHNICAL MITIGATION MEASURES TECHNICAL => Circle hooks as potential mitigation measure? Experimental fishing => 6210 hooks (circle – J-hooks) 267 sharks caught ; 11 species circle J-hook TECHNICAL => Circle hooks as potential mitigation measure? Experimental fishing => 6210 hooks (circle – J-hooks) 267 sharks caught ; 11 species The hook type currently in use in the fishery (J-hook) is the MOST appropriate to limit deep-water shark bycatch circle J-hook TACTICAL => Spatial avoidance measures 1. Species Habitat Suitability Models Data from demersal survey (1997-2018) + onboard observers Maps of presence / absence: 15 species of sharks and rays Maps of abundance: 6 species TACTICAL => Spatial avoidance measures 1. Species Habitat Suitability Models Data from demersal survey (1997-2018) + onboard observers Maps of presence / absence: 15 species of sharks and rays Maps of abundance: 6 species TACTICAL => Spatial avoidance measures (cont.) 2. Overlap with fisheries spatial distribution Fishing effort => VMS data moni tor high moni low tor no. of TAC 0 species 0 of TAC no. DECISION SUPPORT TOOL => FISHERS fishing effort Identification of areas to avoid VS areas of low overlap TACTICAL => Spatial avoidance measures (cont.) 3. Habitat use Kitefin shark Telemetry – electronic tags Detailed information on individuals’ movements and migration Leafscale gulper shark Habitat range and use widely differ between species Spatial avoidance might be an efficient mitigation measure for some species, but not all TACTICAL => Vertical avoidance measures Telemetry => Detailed information on vertical individuals’ movements Diel hour 0 4 8 12 16 20 24 0 Leafscale 200 400 gulper 600 Depth limitations 800 depth(m) shark 1000 (eg. avoid fishing at night 1200 or <500m during daytime) 1400 could be efficient mitigation measures Kitefin for some species shark Telemetry can also inform about post-release survival Electronic tagging Species Scientific name Tagged ‘Recapture’ n n % Leafscale gulper shark Centrophorus squamosus 6 6 100 % Bluntnose sixgill shark Hexanchus griseus 6 6 100 % Kitefin shark Dalatias licha 25 24 96 % Fishers handling practices Demonstrated high 100% post-release survival 80% Moribund of “properly” discarded 60% Dead 40% sharks 20% 0% Bad Good Telemetry can also inform about post-release survival Electronic tagging Species Scientific name Tagged ‘Recapture’ n n % Leafscale gulper shark Centrophorus squamosus 6 6 100 % Bluntnose sixgill shark Hexanchus griseus 6 6 100 % Kitefin shark Dalatias licha 25 24 96 % Fishers handling practices Demonstrated high 100% postManual-releasefor survival best handling80% practicesMoribund of “properly” discarded 60% Dead + easy ID of deep-water40% sharks => fishers sharks 20% 0% Bad Good Summary • Options to avoid deep-water sharks: • TECHNICAL = • Circle instead of J-hooks X 16 ≠ species ! • TACTICAL = => difficulties in • Spatial areas ~ finding efficient • Fishing depths ~ solution for all • Good handling onboard => survival OK • Still important knowledge gaps => research and monitoring needed to be continued.. • Since 2019, prohibited species => incentives to avoid? Many thanks… => to onboard observers and fishers who participated in observer program => to colleagues who helped with the fishing and telemetry experiments, and the manual Questions ? ©Jorge Fontes.
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