Freshwater Climate Risk Index for Biodiversity (FW-CRIB): Using Climate Change Vulnerability and Risk Assessments (CCVA/CCRA) to Guide Freshwater Management in Canada’s Maritime Provinces

Abstract

Climate change is occurring globally, impacting the distribution and fitness of organisms and the potential for ecosystems to provide vital services to human societies. In freshwater ecosystems across the globe, increasing variability and frequency of extremes in precipitation and subsequent water flows, as well as rising trends in water temperature are being observed. To effectively manage freshwater populations, policy measures must be implemented with climate projections in mind. Fisheries and Oceans Canada has recently committed and invested in, in alignment with United Nations Sustainable Goal 13, to combat climate change and its impacts on aquatic ecosystems to ensure climate-resilient aquatic ecosystem management. An essential step in this process is to identify the species and ecosystems that are most vulnerable to climate change to support decision-making for conservation and/or restoration. The Freshwater Climate Risk Index for Biodiversity (FW-CRIB), composed of climate change vulnerability (CCVAs) and risk (CCRAs) assessments can support climate adaptation efforts by helping to understand how climate risk manifests and what actions could help mitigate it. These assessments look at 12 indices across three components (adapting methods from Boyce et al.’s (2022) marine CRIB): exposure of a species in a watershed to future threats, current sensitivities faced by the species in a watershed, and the species’ presence, or lack of, adaptive traits. Results included generally higher risk levels in New Brunswick watersheds, with most species only showing high risk levels under RCP 8.5. Atlantic salmon (Salmo salar) exhibited the highest overall vulnerabilities in the Saint John River Basin watershed under RCP 8.5. Using the open-access and reproducible framework developed through the FW-CRIB as applied in this study can be used to inform provincial and federal policy, and community-level decisions, providing meaningful guidance for predictive management tools.