Research has shown that marine protected areas (MPAs)—areas where fishing and other potentially destructive activities are regulated—are benefitting, not just the fish habitats they are known to aid, but nearby coral reefs as well. MPAs may benefit corals by restoring reef-based food webs and protecting damage from anchors and nutrient runoff.
Marine scientists Elizabeth Selig and John Bruno from the University of North Carolina at Chapel Hill looked at live coral cover, a major determinant of overall coral and ecosystem health, in 310 MPAs and compared the changes to nearby unprotected areas. The surveys, which were conducted between 1969 and 2006, included 4,456 reefs in 83 countries.
Selig and Bruno found that coral cover within the MPAs remained constant and the coral cover in unprotected areas declined. The research also indicated that older MPAs were more effective in preventing coral loss than young MPAs, but the benefits eventually paid off. That is, while coral cover initially continued to decrease in the MPA’s first few years, decline slowed and then eventually stabilized after several years of MPA establishment.
As Selig explained in a press release, “Although the year-to-year changes in coral cover may seem trivial over the short term, the cumulative effects could be substantial over several decades.”
The caption for the above video provided by UNC-Chapel Hill is as follows: “Leigh and Clare surveying a reef in Belize, May 2009. Leigh is measuring coral disease prevalence (the proportion of coral colonies infected with various diseases. Clare is shooting video of the seafloor. She will then analyze the video to determine the portion occupied by corals, macroalgae, sponges, etc. Note how much of the bottom is covered by fleshy macroalgae. A sign of the poor health of this reef.”
Selig, E., & Bruno, J. (2010). A Global Analysis of the Effectiveness of Marine Protected Areas in Preventing Coral Loss PLoS ONE, 5 (2) DOI: 10.1371/journal.pone.0009278