Top predator breeding success in the context of climate change and ocean dynamics – Application to central place foragers of austral polar zone, an individual based modeling approach

• Main Author: Massardier-Galatà, Lauriane
• Other Authors: Institut Sophia Agrobiotech (ISA), Institut National de la Recherche Agronomique (INRA)-Université Nice Sophia Antipolis (1965 - 2019) (UNS)-Centre National de la Recherche Scientifique (CNRS), COMUE Université Côte d'Azur (2015 - 2019), Patrick Coquillard, Christophe Guinet
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2017
• Subjects: Breeding success; Central place forager; Antarctic fur seal; Individual based modeling; Polar front; Climate change; Population dynamics; Foraging distance; Succès de reproduction; Otarie à fourrure antarctique; Modèle individu centré; Front polaire; Changements climatiques; Dynamique de populations; Distance à la ressource; [SDV.SA]Life Sciences [q-bio]/Agricultural sciences; Antarctic; Austral; Kerguelen; Kerguelen Islands; Antarc*; Antarctic Fur Seal; Antarctic Fur Seals; Antarctique*; Arctocephalus gazella
• Online Access: https://theses.hal.science/tel-01614308; https://theses.hal.science/tel-01614308/document; https://theses.hal.science/tel-01614308/file/2017AZUR4050.pdf

Climate change has certain impact on the marine ecosystems. A southward shift in productive frontal systems serving as the main foraging sites for many top predator species is likely to occur in the Subantarctic areas. Central place foragers, as seabirds and pinnipeds, are thus likely to cope with an increase in the distance between foraging locations and their land-based breeding colonies. We studied the impact of climate change on the breeding success and population dynamics of Antarctic fur seals (Arctocephalus gazella) at Kerguelen Islands by means of an individual based model we developped, MarCPFS (Marine Central Place Foragers Simulator) which showed that the survival of the female-pup pair is particularly sensitive to the distribution of preys (abundance and structure), to the memorization abilities of the best resource sites found by the female during the rearing period, to the female size and to the foraging distance which it is necessary to cover at each trip. The results suggest that during the next three decades a southward shift greater than 2 km year-1 could compromise the survival and the sustainability of the populations. A coupling with a model of simulation of the oceanic dynamics and the resource (SEAPODYM) allowed projections till the end of this century based on scenarios RCP8.5 of the IPCC (2014), confirming the trends previously obtained. Globally, these works lead us to conclude with pessimistic perspectives about the sustainability of populations even when considering an evolution through time towards individuals of greater sizes. Les changements climatiques ont un impact certain sur les écosystèmes marins. Un déplacement vers le sud des principaux systèmes de front servant de sites de nourrissage pour de nombreuses espèces de prédateurs supérieurs est susceptible de se produire dans les zones subantarctiques. Les « central place foragers », tels que les pinnipèdes, sont susceptibles de faire face à une augmentation de la distance entre leurs lieux d'alimentation et leurs colonies ...