Some like it hot, but others might not: the implications of climate change for the conservation of South African freshwater crab species

Abstract

Primary freshwater crabs are keystone aquatic species, yet the potential impact of climate change on their distribution and conservation status remains unknown, particularly in biodiversity-rich areas such as South Africa. We employed maximum entropy and climatic niche modelling to evaluate the effects of climate change on the distribution of 17 Potamonautes species in South Africa and estimate protected area coverage for suitable habitats under both current and future climate projections of increased temperature, and the impact on the conservation of these species. Our results indicate that six of the 17 species are likely to experience a net loss of suitable habitat, and seven are projected to experience net habitat gains. Habitat changes for four of the 17 species are dependent on the climate scenario applied. Under predicted temperature increases, P. barbarai and P. isimangaliso are expected to experience significant habitat reduction, with P. isimangaliso being sensitive as a result of substantial predicted losses in both suitable and protected habitat. Conversely, P. depressus , P. flavusjo and P. warreni appear to be the least sensitive to climate change, gaining suitable habitat under both climate models. Unsurprisingly, we found precipitation to be a critical predictor of suitable habitat as these crabs are dependent on freshwater ecosystems. Our results underscore the importance of conservation strategies tailored to the unique predicted response of each species to climate change.