1 Canadian Journal of Fisheries and Aquatic Sciences Achimer 2017, Volume 74, Issue 9, Pages 1422-1430 http://dx.doi.org/10.1139/cjfas-2016-0152 http://archimer.ifremer.fr http://archimer.ifremer.fr/doc/00371/48215/ © Published by NRC Research Press Prey predator interactions in the face of management regulations: changes in Mediterranean small pelagics are not due to increased tuna predation Van Beveren Elisabeth 1, *, Fromentin Jean-Marc 1, Bonhommeau Sylvain 1, 4, Nieblas Anne-Elise 1, Metral Luisa 1, Brisset Blandine 1, Jusup Marko 2, Bauer Robert Klaus 1, Brosset Pablo 1, 3, Saraux Claire 1 1 IFREMER (Institut Français de Recherche pour l’Exploitation de la MER), UMR MARBEC, Avenue Jean Monnet, BP171, 34203 Sète Cedex France 2 Center of Mathematics for Social Creativity, Hokkaido University, N12 W7 Kita-ku, 060-0812 Sapporo, Japan 3 Université Montpellier II, UMR MARBEC, Avenue Jean Monnet, BP171, 34203 Sète cedex, France 4 IFREMER Délégation de l’Océan Indien, Rue Jean Bertho, BP60, 97822 Le Port CEDEX France * Corresponding author : Elisabeth Van Beveren, email address :
[email protected] Abstract : Recently, the abundance of young Atlantic bluefin tuna ( Thunnus thynnus) tripled in the North-western Mediterranean following effective management measures. We investigated whether its predation on sardine ( Sardina pilchardus) and anchovy ( Engraulis encrasicolus) could explain their concurrent size and biomass decline, which caused a fishery crisis. Combining the observed diet composition of bluefin tuna, their modelled daily energy requirements, their population size and the abundance of prey species in the area, we calculated the proportion of the prey populations that were consumed by bluefin tuna annually over 2011-2013.