Abstract for: How Exogenous Stressors Lead to Coral-Algal Phase Shifts
Coral reefs are the most productive ecosystems in the ocean. Roughly twenty-five percent of ocean fish depend on healthy reef ecosystems (NOAA) and coral reef ecosystems provide habitat to between one and three million marine species (Sukhdev et. al, 2010). Coral reef ecosystems also provide a range of ecosystem services including coastal protection, fishing, and tourism (Weijerman, 2017). In recent years, anthropogenic stressors have threatened the resilience and quality of coral reef ecosystems, leading to the emergence of coral-algal phase shifts which result in the loss of productivity and biodiversity (McManus and Polsenberg, 2004). A system- dynamics approach is utilized to model two exogenous stressors and their effects on a contained coral reef ecosystem. Though numerous stressors affect coral reef ecosystem health, coral bleaching and fishing are modeled to quantitatively demonstrate how these stressors diminish coral reef ecosystem health both separately and in tandem. Results suggest that reducing bleaching severity through the reduction of anthropogenic causes that increase ocean temperature is most effective in preventing algal-phase shifts.