Global ChangeIntersection of Nature and Culture

Marine protected areas help coral reefs too

Wednesday, February 17th, 2010

As mentioned in an earlier post, marine protected areas (or MPAs) are a great idea for eliminating fishing pressures and allowing fish stocks to recover.

It’s less well known whether these underwater reserves help preserve reef-building corals, which most fish and other critters depend on one way or another—for habitat or food.

In today’s online issue of PLoS ONE (open accress), Elizabeth Selig and John Bruno conduct an analysis of MPAs worldwide and conclude that these areas are able to stem the loss of corals.¹

That’s good news.

However, they offer this conclusion in the context of several important caveats:

MPAs can play a critical role in the protection of coral reef ecosystems, particularly fisheries. Our results suggest that MPAs are also generally effective in reducing or preventing coral loss. Nonetheless, we were not able to assess their effects on other metrics of reef health including changes in other key taxonomic species, coral composition, richness, reef heterogeneity and other factors that could also indicate that there has been a decline in reef health. MPA benefits may appear modest in the short term, but over several decades could lead to large and highly ecologically significant increases in coral cover as the cumulative importance of small annual effects becomes more important and the number of years of MPA protection increases. However, it remains to be seen whether the observed benefits of MPAs are sufficient to offset coral losses from major disease outbreaks and bleaching events, both of which are predicted to increase in frequency with climate change. Given the time lag for maximizing MPA effectiveness, implementing new MPAs and increasing enforcement should help maximize the ability of MPAs to prevent future coral loss.

Who cares?  Lots of reasons:

• Coral reefs are incredible ecosystems.  If you have never dived or snorkeled on a healthy coral reef, put it on your list of 10 things to do before you die.   My recommendations are the Great Barrier Reef (Australia), the Cayman Islands, Hawaii, and the islands of the Netherlands Antilles.  We owe it to future generations to preserve these ecosystems in the wild rather than in books and aquaria.
• Reefs are incredibly species rich.  Protecting them protects a significant fraction of coastal marine biodiversity.
• Reefs are very productive ecosystems that provide a food source and habitat for thousands of species.  Protect the corals, and you end up protecting many other species.
• Many coastal communities depend on reefs for their livelihoods (e.g., seafood harvesting and tourism).  This makes reef management critical for economic as well as ecological sustainability.  But, as this article suggests, local management is challenged by the fact that global threats, such as ocean acidification, disease, and rising temperature impacts on coral bleaching, may trump what local people can control.

¹Selig ER, Bruno JF, 2010 A Global Analysis of the Effectiveness of Marine Protected Areas in Preventing Coral Loss. PLoS ONE 5(2): e9278. doi:10.1371/journal.pone.0009278

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Photo credit:  One of my photos that you can see at my flickr site.

Tags: coral reef
Posted in biodiversity science, nature and culture, sustainability | 2 Comments »