Abstract

Spatial assessment of the risks faced by marine habitats provides essential information for adaptation to the impacts of multiple anthropogenic stressors. Climate change is one of the main stressors affecting the persistence and resilience of healthy marine ecosystems. However, protection against other stressors such as marine habitat loss and direct exploitation of natural marine resources is needed to ensure that conservation efforts are not threatened by cumulative combined effects. We used habitat risk assessment to explore the cumulative impacts of multiple stressors, including aquaculture activities, fishing vessel pressure, and climate change, on marine habitats of giant kelp forests. The assessment was applied in Chilean Patagonia, focusing on three protected areas: Magdalena Island National Park, Guaitecas National Reserve, and Kawésqar National Reserve. Our findings reveal that sea surface temperature increases, salmon farming, and the aquaculture-associated ship fleet are the stressors contributing most significantly to risk. High-risk areas are concentrated in northern Patagonia, specifically in the fjords of Guaitecas National Reserve and Magdalena Island National Park, with some risk hotspots found in the fjords of Kawésqar National Reserve. The highest risk levels are observed in scenarios that include both climate change and industrial salmon farming. Identifying the areas most at-risk is crucial for marine spatial planning because it allows for the design of targeted conservation actions to mitigate stressors and prevent risks from reaching levels that could compromise the integrity of marine habitats. The spatial approach used is key for informing future planning processes in Chilean Patagonia, where conflicts between intensive salmon farming, small-scale fishing, traditional Indigenous sea uses, and nature conservation are escalating. Despite some limitations in the data, our study provides valuable insights that can guide future conservation planning and policy-making, helping to balance economic activities with the need to protect and maintain the health of marine habitats in Chilean Patagonia.