Cold-water habitats, climate refugia, and their utility for conserving salmonid fishes

Abstract

Anthropogenic climate change is warming global temperatures, with significant implications for salmonid fishes that depend on the availability of cold water during one or more life stages. Along the southern range extents of many species, and elsewhere that warm temperatures are increasingly problematic, identification and protection or restoration of habitats that may serve as climate refugia where local populations can persist is emerging as an important conservation tactic. In this perspective piece, we address the concept and utility of climate refugia—drawing a distinction with the more commonly considered thermal refuges—describe technological advances that enable accurate temperature mapping and species distribution modeling in lotic environments, and outline key uncertainties and opportunities to chart a constructive path forward on a topic that will continue to grow in importance. Identifying climate refugia is not a panacea for salmonid conservation, but we argue that there are tangible benefits to doing so, not the least of which are the options it affords for thinking and acting strategically within the context of a changing climate this century.