Marine protected areas help coral reefs survive climate change

In the last few years, research has emerged that has made many experts question whether marine protected areas (MPAs) will be effective in helping to preserve coral reefs. A new study in the eastern Caribbean is demonstrating that MPAs can, in fact, be successful in defending coral reefs from the harmful impacts of global climate change.

Robert Steneck is a professor of Marine Biology at The University of Maine who has studied coral reefs for four decades.

“MPAs can help coral reefs, but studies to the contrary just weren’t measuring the right things at the right scales,” said Steneck.

“The idea behind MPAs is that, by reducing fishing pressure, you increase the number of seaweed-eating fish, and they decrease the amount of harmful seaweed, which makes it easier for baby corals to get started and thrive on the reef. But coral reefs are complicated, and lots of other things can affect fish numbers, their ability to control the growth of algae and the ability of corals to take advantage of this.”

The analysis was focused on reef protection efforts across over 400 miles of corals in the Leeward Islands of the Caribbean.

The study revealed that local fisheries management had led to a 62 percent increase in the density of young corals. According to the researchers, this density helps to empower the ecosystem to recover from destructive events such as hurricanes and coral bleaching.

Study co-author Professor Peter Mumby explained that, due to the fact that taking field measurements on coral reefs is time consuming, many researchers take shortcuts and use widely available data to examine how reefs respond to protection.

“While it sounds obvious, we show that our ability to detect the benefits of MPAs on corals improves dramatically when you take more detailed measurements,” said Professor Mumby. “For example, a simple option is to count the number of herbivorous fishes. But if, instead, you estimate how intensively these fishes feed, you obtain a much clearer and compelling insight.”

Professor Steneck pointed out that there is not one single management solution for every ecosystem, and especially not for coral reefs.

“Certainly, stresses on reef corals from climate and atmospheric changes are serious and beyond direct management control. However, we suggest that local management measures can bolster the recovery of corals after damaging events and, eventually, improve their overall condition.”

The study is published in the journal Science Advances.

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By Chrissy Sexton, Earth.com Staff Writer