Assessing Coral Reef Conservation Policy: Marine Protected Areas in a Changing Coastal Landscape

Abstract

Over the past few decades coral reefs have undergone dramatic macroalgal phase shifts that have come to dominate reef ecology, impacting coral cover and reef health (Bellwood et al. 2004). Marine Protected Areas (MPAs) are a conservation measure that prohibit fishing and attempt to fight macroalgal phase shifts by promoting a stronger topdown herbivory pressure on macroalgal overgrowth (Mumby 2009). This study aims to assess the effectiveness of MPAs by comparing two reefs located along the Mesoamerican Barrier Reef in Honduras. One reef system, Cayos Cochinos, is sanctioned an MPA while the other, Utila, is a non-protected reef site. In addition to direct comparisons between sites, the theory behind MPAs is tested and support for alternative conservation measures is presented. I conclude that coastal water eutrophication is capable of undermining the effectiveness of MPAs because it supplies macroalgal species with an abundance of what would otherwise be growth-limiting nutrients. Eutrophication allows macroalgae to flourish even in the presence of a strong herbivory pressure. Therefore, Marine Protected Areas targeting reefs under the threat of eutrophication should include other measures to control nutrient induced algal blooms in order to maximize reef health.