A different destiny after the ice age: Impacts of climate change on the global biogeography of Carasobarbus

Abstract

Climate change poses a significant global challenge, profoundly affecting species distribution. In recent years, research focusing on the impacts of climate change on freshwater taxa has been relatively limited compared to studies on terrestrial taxa. This study seeks to identify hotspots and occurrences of all Carasobarbus freshwater fish species while also predicting the potential implications of climate change through the use of ensemble species distribution modeling (ESDM). Analyze climatic changes across various temporal scales: the Mid-Holocene (6000 years BP), the Last Glacial Maximum (21,000 years BP), the present, and future projections (2061–2080). Global circulation models (GCMs) showed strong predictive capabilities for the species climatic niches, with Area under the curve (AUC) and true skill statistics (TSS) values. Key predictors included Annual Mean Temperature, Mean Temperature of the Driest Quarter, and Precipitation of the Driest Month. The analysis revealed varied responses to climate change: Five and seven species are expected to lose climatically suitable habitats (losers) in SSP 126 and SSP 585, respectively, indicating heightened vulnerability, in SSP126 and SSP 585 four and three species are expected to see an increase (Winners) in their range respectively, and additionally, in SSP 126 and SSP 585 two and one species are anticipated to maintain approximately stable (Under 1 % change) distributions within their ranges under the specified scenarios. Additionally, the Iran-Anatolian hotspot emerges as crucial for Carasobarbus populations globally. The research highlights the effects of climate change on Carasobarbus distribution patterns, providing essential insights for conservation strategies and management to protect biodiversity in vulnerable regions.