The effects of ocean climate change on environmental niches of pelagic sharks

Shifts in the distributions and abundance of marine organisms are occurring globally as a major consequence of climate change. Marine fish are no exception, with significant changes documented across taxa [1]. However, the effects of ocean warming on the niches of oceanic pelagic sharks are poorly understood by comparison [2]. For example, in the North Atlantic Ocean, there are currently no predictions available about how pelagic sharks may respond to future ocean environmental change. Additionally, overfishing of many pelagic shark species is already occurring with tens of millions of individuals caught each year by high-seas fisheries with significant reductions in catch rates documented for many species. Thus, there is an urgent need to understand how ocean climate changes may alter distributions and centres of abundance, which may interact with fisheries to further impact future sustainability of populations [3]. The aim of this project is to use a unique database of the movements of 2,000 satellite-tracked pelagic sharks (23 species) with 3-D environmental variables extracted per location, to determine present day distributions and environmental niches. These relationships will be used to model global spatial densities and niches of sharks, and by applying outputs from global Earth System models, will explore how shark distributions may change over the next century.