Towards a better characterisation of deep-diving whales’ distributions by using prey distribution model outputs?

• Published in: PLOS ONE
• Main Authors: Virgili, Auriane, Hedon, Laura, Authier, Matthieu, Calmettes, Beatriz, Claridge, Diane, Cole, Tim, Corkeron, Peter, Dorémus, Ghislain, Dunn, Charlotte, Dunn, Tim, Laran, Sophie, Lehodey, Patrick, Lewis, Mark, Louzao, Maite, Mannocci, Laura, Martínez-Cedeira, José, Monestiez, Pascal, Palka, Debra, Pettex, Emeline, Roberts, Jason, Ruiz, Leire, Saavedra, Camilo, Santos, M. Begoña, van Canneyt, Olivier, Bonales, José Antonio Vázquez, Ridoux, Vincent
• Other Authors: Observatoire pour la Conservation de la Mégafaune Marine (PELAGIS), LIttoral ENvironnement et Sociétés (LIENSs), La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS)-La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), LEB Aquitaine Transfert-ADERA, CLS Space Oceanography Division, Collecte Localisation Satellites (CLS), Bahamas Marine Mammal Research Organisation, NOAA Northeast Fisheries Science Center, National Oceanic and Atmospheric Administration (NOAA), Joint Nature Conservation Committee, Marine Habitats Team, Basque Research and Technology Alliance (BRTA), 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), CEMMA, Coordinadora para o Estudio dos Mamiferos Marinos, Biostatistique et Processus Spatiaux (BioSP), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), ADERA, Cellule Cohabys (Cohabys), Duke University Durham, AMBAR Elkartea Organisation Bizkaia, Spain, Instituto Español de Oceanografía (IEO), Málaga., Alnilam Research and Conservation Madrid, Spain
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2021
• Subjects: [SDE]Environmental Sciences; Physeter macrocephalus
• Online Access: https://hal.science/hal-03335810; https://hal.science/hal-03335810/document; https://hal.science/hal-03335810/file/journal.pone.0255667.pdf; https://doi.org/10.1371/journal.pone.0255667

International audience In habitat modelling, environmental variables are assumed to be proxies of lower trophic levels distribution and by extension, of marine top predator distributions. More proximal variables, such as potential prey fields, could refine relationships between top predator distributions and their environment. In situ data on prey distributions are not available over large spatial scales but, a numerical model, the Spatial Ecosystem And POpulation DYnamics Model (SEAPODYM), provides simulations of the biomass and production of zooplankton and six functional groups of micronekton at the global scale. Here, we explored whether generalised additive models fitted to simulated prey distribution data better predicted deep-diver densities (here beaked whales Ziphiidae and sperm whales Physeter macrocephalus ) than models fitted to environmental variables. We assessed whether the combination of environmental and prey distribution data would further improve model fit by comparing their explanatory power. For both taxa, results were suggestive of a preference for habitats associated with topographic features and thermal fronts but also for habitats with an extended euphotic zone and with large prey of the lower mesopelagic layer. For beaked whales, no SEAPODYM variable was selected in the best model that combined the two types of variables, possibly because SEAPODYM does not accurately simulate the organisms on which beaked whales feed on. For sperm whales, the increase model performance was only marginal. SEAPODYM outputs were at best weakly correlated with sightings of deep-diving cetaceans, suggesting SEAPODYM may not accurately predict the prey fields of these taxa. This study was a first investigation and mostly highlighted the importance of the physiographic variables to understand mechanisms that influence the distribution of deep-diving cetaceans. A more systematic use of SEAPODYM could allow to better define the limits of its use and a development of the model that would simulate larger prey ...