Marine climate variability and change in the Torres Strait

Abstract

Small islands are highly vulnerable to climate change as rising sea levels, warming temperatures and ocean acidification threaten marine ecosystems, livelihoods and traditional way of life. The Australian Torres Strait Islands are a low-lying archipelago between northern Australia and Papua New Guinea and face existential threats akin to small island developing states in the Pacific. We analyse trends in ocean and atmospheric variables and synthesise changes that occurred in key Torres Strait marine habitats and resources since the 1970 s. We find increasing trends in temperature, marine heatwaves, sea surface height and dry-season wind run. Other variables including solar exposure, rainfall, river discharge and net primary productivity show variability but no trend, and are typically aligned with large El Niño Southern Oscillation (ENSO) events. Habitats such as mangroves, seagrass meadows and coral reefs are naturally variable, but sensitive to compounding climate extremes, including ENSO-related anomalies and sustained ocean warming. Our study further explores the dependence of commercial and cultural fisheries on these foundation habitats, highlighting that habitat fluctuations combined with ocean warming are already impacting some fisheries (e.g. tropical rock lobster). Cultural totemic species such as dugongs and green turtle are also under pressure from climate change. Our synthesis informs efforts to respond and adapt to climate change. Moreover, we highlight that several interconnected initiatives are needed, including long-term monitoring, climate change communication, adaptive strategies for fisheries and communities, as well as strong governance and policy support alongside continued efforts to empower communities through capacity building, education, and equitable engagement.