ABSTRACT:

Climate change causes warming of the oceans, and there is consensus that many marine ectotherms, including marine invertebrates and fishes, respond to the increase in temperature by showing latitudinal range shifts in their distribution. However, the effect of ocean warming on the bathymetric distribution of marine ectotherms remains largely theoretical, and few works evidence bathymetric range shifts. Since warming is not exclusive of surface waters, the depth distribution of species should also be affected by warming. Here, I exemplify bathymetric distribution ranges of marine ectotherms from the North Atlantic and advocate that there will be species-specific shifts in the fundamental ecological niches occupied in response to climate warming. Combined temperature and pressure acclimation to match oxygen capacity demands at physiological thresholds is key to this process. Species-specific tolerance of hydrostatic pressure and temperature determines depth distribution ranges of marine ectotherms.