Navigating uncertainty: an assessment of climate change risks to the marine and coastal environment of Sri Lanka

Sri Lanka is highly vulnerable to the impacts of marine climate change due to the low coastal profile, which is densely populated with many rural areas dedicated to fishing and aquaculture. Motivated by this, this study aimed to compile and analyse the available evidence and identify steps to improve climate adaptation by undertaking an assessment of marine climate change risks for Sri Lanka. The stepwise approach consisted of a comprehensive literature review and synthesis of risks, followed by appraisal, validation and scoring by expert stakeholders. Here we present a summary of key findings regarding marine climate variables (temperature, sea-level rise, ocean circulation, salinity, ocean acidification, dissolved oxygen, storminess, precipitation and wind), and risks to marine biodiversity and ecosystem services. The most important biodiversity risks identified include decreasing plankton productivity; threats to sea turtles; changes in fish communities; increasing threats to coral reefs; changes to mangrove and seagrass habitats; shoreline erosion; and increasing risk of bio-invasions. Key risks to ecosystem services include declining fisheries; damage and disruption to critical infrastructure and services; threats to tourism; and loss of protective coastal habitats. We also identified important knowledge gaps and uncertainties involving lack of climate data and evidence of impacts. Finally, we provide recommendations regarding marine monitoring and research, and options to strengthen climate policies and climate adaptation in Sri Lanka.