Riverine fish species diversity in a biodiversity hotspot region under climate change impacts: distribution shifts and conservation needs

Abstract

The future changes in the spatial distribution and richness of 131 riverine fish species were investigated at 1481 sites in Iran under optimistic and pessimistic climate change scenarios of 2050 and 2080. The maximum entropy model was used to predict species’ potential distribution under current and future climate conditions. The hydrologic unit (HU) occupancy of the target species through the use of nine environmental variables was modeled. The most important variable determining fish occupancy was HU location, followed by elevation, climate variables, and slope. Thirty-seven species decrease potential habitat occupancy in all future scenarios. The southern Caspian HU faces the highest future species reductions. The southern Caspian HU, western Zagros, and northwestern Iran will be at higher risk for species richness reduction. Managers could use these results to plan conservational strategies to ease the movement and dispersal of species, especially those that are at risk of extinction or invasion.