SYDNEY: Many of the sanctuaries for coral reefs in the Indian Ocean are unable to protect the reefs from the worst of climate change, a team of international scientists has warned.

The sanctuaries are in the wrong places and far too small, they have found. While effective in protecting local fish, they may not be of much help in enabling reefs to recover from major coral bleaching events caused by ocean warming, the scientists said.
Their study on corals is the largest of its kind, covering 66 sites in seven countries in the Indian Ocean and spanning over a decade. The findings were published in the journal PLoS ONE.

Many of these sanctuaries were set up in the late 1960s and early 1970s to protect fish, before climate change and its impact on corals became a major issue, the researchers said.

The team, which includes Nick Graham and Shaun Wilson of the Centre of Excellence for Coral Reef Studies (CoECRS), and colleagues from Newcastle University and the Wildlife Conservation Society, urged immediate action to prevent the collapse of this important marine ecosystem.

Several of these areas are small, and are surrounded by areas of sea which are heavily fished or otherwise exploited.

These existing zones should not be removed, but new areas are needed in the right places to enable corals to recover from the mass die-offs caused by rising temperatures, say the scientists.

"When you have a major disturbance like bleaching, it can affect a huge area of the reef," explained Shaun Wilson. "If you have extensive reserve systems, then the chances are much higher they will contain small areas within that escape bleaching which can help to recharge the reef as a whole."

Wilson added that Australia's approach on the Great Barrier Reef, where a third of the total area is protected by 'green' zones, was a model for how to protect large reef systems under climate change.

"The Great Barrier Reef Marine Park Authority have put a lot of effort into determining exactly where these protected zones should be located to give the reef the best over chance of recovery from bleaching events," he says.

Co-author Nick Graham, who joins CoECRS next month, said "new protected zones need to focus on areas identified as escaping or recovering well from climate change impacts."

The team has investigated the long-term impact of a major coral die-off across the Indian Ocean caused by warmer waters since 1998.