Marine protected areas do protect corals

Hawai'i has a range of marine protected areas, with varying kinds and degrees of protection—from no fishing to virtually no human activity at all--but do they work?

That's been an assumption—but there is new evidence that, for corals and perhaps for fisheries as well, they do.

In the February 2010 issue of the online scientific journal PloS One, University of North Carolina researchers Elizabeth Selig and John Bruno published the paper, “A Global Analysis of the Effectiveness of Marine Protected Areas in Preventing Coral Loss.”

Corals are particularly important, because, the authors write, “Coral loss has cascading effects throughout reef ecosystems leading to subsequent changes in the population dynamics of reef inhabitants.”

They reviewed more than 8,000 coral surveys from more than 4,000 reefs around the globe, and their conclusions were favorable for marine protected areas (MPAs).

They found that coral cover remained stable in protected areas, but declined on unprotected reefs. And they found, as might be expected, that longer protection was more effective than shorter.

“These findings suggest that MPAs can be a useful tool not only for fisheries management, but also for maintaining coral cover,” the paper said.

In an email to colleagues, co-author Bruno wrote:

“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.”

© Jan TenBruggencate 2010