Marine protected areas are one of the main tools to prevent the sharp decline in coral reefs being observed across the world. However, a recent scientific evaluation indicates some reefs in protected areas or far from human populations can still thrive, but only a small percentage can achieve the multiple goals of plentiful fish stocks, high fish biodiversity, high fish grazing, and well-preserved ecosystem functions.

To come to this conclusion, an international team of coral reef scientists from James Cook University (Coral CoE at JCU),  WCS (Wildlife Conservation Society) and other groups assessed around 1,800 tropical reefs in 41 tropical countries.

“Only five percent of the reefs were simultaneously able to meet the combined goals of providing enough fishing stocks, maintaining biodiversity and a working ecosystem,” said the lead author, Professor Josh Cinner, a scientist from the ARC Centre of Excellence for Coral Reef Studies at James Cook University. “These are like the Hollywood A-listers of coral reefs. They have it all, but they’re also rare and live in exclusive areas—remote locations with little human pressure. Our study shows how to help other coral reefs get on that A-list.”

“Studies such as this show the limitations of some marine protected areas, which are considered critical by most scientists and managers for effective conservation and management. This study shows that their placement is critical to achieving conservation goals and therefore can help scientists and managers to determine where to focus efforts,” said Dr. Tim McClanahan, Senior Conservation Zoologist for WCS and a co-author on the study.

McClanahan added: “As only a small number of coral reefs were found to possess relatively pristine ecological conditions, other protected areas should be seen primarily as achieving fisheries sustainability goals when used in appropriate human development contexts.”

The research team assessed if no-fishing marine reserves and other fisheries restrictions helped reefs to meet multiple goals. The study found that implementing such local efforts helped, but only if the management efforts are in the right locations.

“It’s all about location, location, location,” Cinner added. “Marine reserves placed in areas with low human pressures had the best results for helping reefs get on the A-list. We also had a B-list of reefs, which met all the goals, but to a lesser degree. Reserves in areas with intermediate human pressure made the biggest difference to getting reefs on our B-list. Quite simply, they occurred in less exclusive locations than our A-listers.”

However, marine reserves made little difference in areas where the environment was so severely degraded that only wider seascape conservation could help.

Co-author Jessica Zamborain-Mason, a Coral CoE and JCU PhD candidate, says coral reefs worldwide are facing intense degradation due to numerous anthropogenic drivers, such as overfishing, pollution, and climate change.

“There is an increasing need to manage coral reefs to meet multiple goals simultaneously,” she said.

“Our findings provide guidance on where to strategically place local management to achieve the greatest benefits.”

Co-author Professor Nick Graham from Lancaster University says the study uses data to show what works.

“Coral reef science and management is often focussed on meeting just a single goal,” Prof Graham said. Adding “Managing for just one goal at a time is common, but what if you want it all? The multiple goals of biodiversity, fisheries and functioning ecosystems are often required at any given location, yet the science to understand when and how this can be achieved has been lacking.”

“We looked at the fish communities, not the coral communities, and these are affected by different drivers—overfishing really drives the former and climate change the latter.”

“The study not only has important implications for the placement of new marine reserves, but is also relevant to future socioeconomic changes, such as how infrastructure development and population growth may impact the efficacy of reef conservation,” Prof Cinner said.

“We show where managers will be able to maximise multiple goals, and likewise, where they will be wasting their time.”

The study concludes that, while international action on climate change is crucial for ensuring a future for coral-dominated reefs, effective management is also critical to sustaining reefs—and the millions of people whose livelihoods depend on them.

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