FN Archimer Export Format PT J TI Trophic models: What do we learn about Celtic Sea and Bay of Biscay ecosystems? BT AF MOULLEC, Fabien GASCUEL, Didier BENTORCHA, Karim GUENETTE, Sylvie ROBERT, Marianne AS 1:1,2;2:1;3:1;4:3;5:4; FF 1:;2:;3:;4:;5:PDG-RBE-STH-LTBH; C1 UBL, Agrocampus Ouest, UMR Ecol & Ecosyst Hlth 985, 65 Rue St Brieuc,CS 84215, F-35042 Rennes, France. Univ Montpellier, MARBEC, UMR 248, IRD, Pl E Bataillon, F-34095 Montpellier, France. EcOceans, 12 St Croix, St Andrews, NB E5B 2K5, Canada. IFREMER, Unite Sci & Technol Halieut, Lab Technol & Biol Halieut, 8 Rue Francois Toullec, F-56325 Lorient, France. C2 AGROCAMPUS OUEST, FRANCE IRD, FRANCE ECOCEANS, CANADA IFREMER, FRANCE SI LORIENT SE PDG-RBE-STH-LTBH UM MARBEC IN WOS Ifremer jusqu'en 2018 copubli-france copubli-p187 copubli-int-hors-europe IF 2.506 TC 27 UR https://archimer.ifremer.fr/doc/00377/48771/49169.pdf LA English DT Article DE ;Ecosystem Approach to Fisheries Management (EAFM);Bay of Biscay;Celtic Sea;Ecopath with Ecosim;EcoTroph;Trophic indicators AB Trophic models are key tools to go beyond the single-species approaches used in stock assessments to adopt a more holistic view and implement the Ecosystem Approach to Fisheries Management (EAFM). This study aims to: (i) analyse the trophic functioning of the Celtic Sea and the Bay of Biscay, (ii) investigate ecosystem changes over the 1980–2013 period and, (iii) explore the response to management measures at the food web scale. Ecopath models were built for each ecosystem for years 1980 and 2013, and Ecosim models were fitted to time series data of biomass and catches. EcoTroph diagnosis showed that in both ecosystems, fishing pressure focuses on high trophic levels (TLs) and, to a lesser extent, on intermediate TLs. However, the interplay between local environmental conditions, species composition and ecosystem functioning could explain the different responses to fisheries management observed between these two contiguous ecosystems. Indeed, over the study period, the ecosystem's exploitation status has improved in the Bay of Biscay but not in the Celtic Sea. This improvement does not seem to be sufficient to achieve the objectives of an EAFM, as high trophic levels were still overexploited in 2013 and simulations conducted with Ecosim in the Bay of Biscay indicate that at current fishing effort the biomass will not be rebuilt by 2030. The ecosystem's response to a reduction in fishing mortality depends on which trophic levels receive protection. Reducing fishing mortality on pelagic fish, instead of on demersal fish, appears more efficient at maximising catch and total biomass and at conserving both top-predator and intermediate TLs. Such advice-oriented trophic models should be used on a regular basis to monitor the health status of marine food webs and analyse the trade-offs between multiple objectives in an ecosystem-based fisheries management context. PY 2017 PD AUG SO Journal Of Marine Systems SN 0924-7963 PU Elsevier Science Bv VL 172 UT 000403991200010 BP 104 EP 117 DI 10.1016/j.jmarsys.2017.03.008 ID 48771 ER EF