Data from: Assessing the vulnerability of Africa's freshwater fishes to climate change: a continent-wide trait-based analysis

Climate change is a key driver of biodiversity loss across the globe, and freshwater fishes are predicted to be among the most vulnerable taxa. African freshwater ecosystems are home to one of the most unique and diverse ichthyo-faunas on the planet, and freshwater fish species provide essential livelihoods for millions of people living in riparian communities across the continent. Although nearly one sixth of African freshwater fishes have been designated as endangered or vulnerable to extinction by the IUCN Red List assessment, the effects of climate change on these species have not been explored on a continent-wide scale. In this study, we present the first trait-based climate change vulnerability assessment (CCVA) comprising the majority (85%) of Africa's currently described freshwater fishes. We assembled data relating to three dimensions of vulnerability including sensitivity, adaptive capacity, and exposure. In addition, we developed an index of 'conservation value' based on traditional conservation metrics including extinction risk, endemism, and provision of ecosystem services. We found that almost 40% of African freshwater fishes are vulnerable to climate change, mostly owing to the many species with highly specialized habitat and life-history requirements, and because of the numerous anthropogenic stressors they face. High proportions of species within the Nothobranchiidae and Cichlidae families were found to be vulnerable. Regions with high frequencies of vulnerable species included the African rift valley lakes, the Congo River drainage, and the coastal rivers of West Africa. Several important data deficiencies were identified relating to species' population sizes, genetic variability, and life history traits, and constitute priority research areas for the future. In addition, we highlighted some cases where traditional conservation approaches overlook species and regions that are predicted to be threatened by climate change.

气候变化是全球生物多样性丧失的核心驱动因素，淡水鱼类被认为是最易受影响的生物类群之一。非洲淡水生态系统孕育了全球最具独特性且物种多样性最高的鱼类区系之一，淡水鱼类为整个非洲大陆沿河社区的数百万民众提供了至关重要的生计支撑。尽管世界自然保护联盟红色名录（IUCN Red List）评估显示，近六分之一的非洲淡水鱼类已被列为濒危或易灭绝物种，但气候变化对这些物种的影响尚未在全大陆尺度上开展系统性研究。本研究完成了首个基于功能性状的气候变化脆弱性评估（climate change vulnerability assessment, CCVA），覆盖了非洲目前已描述淡水鱼类总量的绝大多数（85%）。我们收集了涵盖脆弱性三大维度的数据，即敏感性、适应能力与暴露度。此外，我们基于灭绝风险、特有性以及生态系统服务供给等传统保护指标，构建了“保护价值”指数。研究结果显示，近40%的非洲淡水鱼类易受气候变化影响，这主要源于众多物种对栖息地与生活史具有高度特化的需求，同时它们还面临着诸多人为胁迫因子。其中，假鳃鳉科（Nothobranchiidae）与慈鲷科（Cichlidae）内的高比例物种被认定为易受气候变化影响。脆弱物种高发区域包括非洲大裂谷湖泊群、刚果河水系以及西非沿海河流。研究同时识别出若干重要的数据缺口，涉及物种种群规模、遗传变异以及生活史性状，这些均为未来优先开展的研究方向。此外，我们还指出了若干传统保护手段未能覆盖的、预计将受气候变化威胁的物种与区域案例。