The vulnerability of Ireland's freshwater fish to climate change

Climate change can affect fish species directly (e.g. through physiological stress) or indirectly (e.g. species interactions). Whether individual species will experience net benefits or net losses is important to understand from a fisheries management perspective. Ireland has a unique freshwater fish community that faces considerable uncertainty in relation to the impact of climate change. Vulnerability of fish species and subspecies (n = 32) in Ireland were investigated through an expert‐based questionnaire and a trait‐based assessment. Fish species were assessed based on exposure, sensitivity and adaptive capacity. The expert‐based questionnaire predicted that one species, Arctic char Salvelinus alpinus was assigned the rank of high vulnerability, seven species were assigned moderate to high vulnerability, twenty species were assigned moderate vulnerability, and four species were of low to moderate vulnerability. Life‐history characteristics of the fish species were analysed to identify traits characteristic of vulnerable fish species (e.g. Vulnerability to fishing and Trophic level). Coldwater species are highly vulnerable, with indirect effects through interactions with other species or in combination with non‐climatic stressors (e.g. water quality & barriers to migration) being a significant concern. The results provide a vulnerability ranking for Ireland's freshwater fish, that can be utilised by fisheries managers and allows for prioritising of an often‐limited conservation resource.