Climate change shifts abiotic niche of temperate skates towards deeper zones in the Southwestern Atlantic Ocean

Climatic changes are disrupting distribution patterns of populations through shifts in species abiotic niches and habitat loss. The abiotic niche of marine benthic taxa such as skates, however, may be more climatically stable compared to upper layers of the water column, in which aquatic organisms are more exposed to immediate impacts of warming. Here, we estimate climate change impacts in Riorajini, a tribe of four skates, as a proxy to (1) evaluate the vulnerability of a temperate coastal zone in the Atlantic Southwest, and (2) study niche dynamics in a scenario of environmental changes on this group of threatened species. We modelled each species abiotic niche under present (2000-2014) and future (2100, Representative Concentration Pathway 8.5) climatic scenarios, then measured niche overlap, stability, expansion, and unfilling. Our results reveal an expansion of suitable environment for the occurrence of the tribe in up to 20% towards deeper areas (longitudinal shift), although still within the limits of the continental shelf. We discussed the downfalls of such shift to the species and to the local biota in newly invaded areas, and suggest that even deeper layers of marine temperate zones are vulnerable to dramatic environmental changes as a consequence of global warming.