Contrasted optimal environmental windows for both sardinella species in Senegalese waters

• Published in: Fisheries Oceanography
• Main Authors: Diankha, Ousmane, Ba, Aliou, Brehmer, Patrice, Brochier, Timothee, Sow, Bamol Ali, Thiaw, Modou, Gaye, Amadou Thierno, Ngom, Fambaye, Demarcq, Herve
• Other Authors: Laboratoire de Physique de l'Atmosphère et de l'Océan Siméon Fongang (LPAO-SF), École Supérieure Polytechnique de Dakar (ESP), Université Cheikh Anta Diop de Dakar Sénégal (UCAD)-Université Cheikh Anta Diop de Dakar Sénégal (UCAD), Université Cheikh Anta Diop de Dakar Sénégal (UCAD), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD), Institut Sénégalais de Recherches Agricoles Dakar (ISRA), Unité de modélisation mathématique et informatique des systèmes complexes Bondy (UMMISCO), Université Gaston Berger de Saint-Louis Sénégal (UGB)-Université de Yaoundé I (UY1)-Institut de la francophonie pour l'informatique-Université Cadi Ayyad Marrakech (UCA)-Sorbonne Université (SU)-Institut de Recherche pour le Développement (IRD France-Nord )-Université Cheikh Anta Diop de Dakar Sénégal (UCAD), Laboratoire d'Océanographie, des sciences de l'environnement et du climat Sénégal (LOSEC), Université Assane Seck de Ziguinchor Sénégal (UASZ), MARine Biodiversity Exploitation and Conservation (UMR MARBEC), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), European Project: 603521,EC:FP7:ENV,FP7-ENV-2013-two-stage,PREFACE(2013)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: recruitment success; Sardinella aurita; Sardinella maderensis; upwelling; West Africa; ACL; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDV.EE.ECO]Life Sciences [q-bio]/Ecology; environment/Ecosystems; [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; Gam; North Atlantic; North Atlantic oscillation
• Online Access: https://hal.science/hal-01826581; https://hal.science/hal-01826581/document; https://hal.science/hal-01826581/file/Diankha_etal_FO_2018.pdf; https://doi.org/10.1111/fog.12257

International audience We investigate Sardinella aurita and Sardinella maderensis recruitment success relative to the variability of oceanographic conditions in Senegalese waters using generalized additive models (GAM). Results show that recruitment of both species is marked by a strong intra-annual (seasonal) variation with minimum and maximum in winter and summer, respectively. Their interannual variations are synchronous until 2006 (recruitment decreasing), while from 2007 there is no synchrony. The model developed shows that sardinella recruitment variability is closely related to the tested environmental variables in the study area. However, the key environmental variables influencing the recruitment success are different for both species: the Coastal Upwelling Index and the sea surface temperature for S.aurita and S.maderensis, respectively. We report that recruitment success of S.aurita and S.maderensis are associated with distinct ranges of sea surface temperature, upwelling intensity, wind-induced turbulence, concentration of chlorophyll-a and north Atlantic oscillation index. Considering food security and socio-economic importance of both stocks, we recommend that consideration is given to the environmental variability in the small pelagic fish national management plans, particularly in the context of climate change.