My former PhD student (now at Conservation International) Dr. Elizabeth Selig and I recently published a paper in PLoS One (Selig and Bruno 2010) on the effectiveness of marine protected areas in preventing coral loss. The study indicates that MPAs can, on average, reduce coral losses and in some cases promote coral growth. This is an important finding because for years there has been broad speculation that MPAs and other forms of local fisheries restrictions could also benefit reef-building corals. Yet until now, no study had actually tested the generality of that idea.
Our results also suggest that older MPAs were generally more effective in preventing coral loss. Initially, coral cover continued to decrease after MPA establishment. Several years later, however, rates of coral cover decline slowed and then ceased. The analysis was based on a global database of 8534 reef surveys from 1969-2006. We used this long-term record of reef communities to compare changes in coral cover inside 310 MPAs to that on over 4000 unprotected reefs in 83 countries.