Conservation policies informed by food system feedbacks can avoid unintended consequences.

Understanding the feedbacks between food systems and conservation policies can help avoid unintended environmental consequences. Using a survey-based choice experiment and economic modelling, we quantify the potential impact of tourists' responses to a shift in offshore fish supply after the designation of a large-scale marine protected area in Palau. We find that this conservation policy may increase offshore fish prices and tourists' consumption of reef fish, thereby further endangering local reef ecosystems. However, if tourists are offered a sustainable offshore choice, their demand for fish could be kept at current levels, and environmental impacts from increased reef fish consumption would be avoided.