Corals get climate survival guide

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Strategies to help vulnerable marine ecosystems survive the impact of climate change have been published by conservationists.

Coral reefs and mangroves are being degraded by global warming, pollution and coastal developments, they said.

The authors say limiting the human impact on the habitats will allow them to be more resilient to climate shifts.

The reports have been produced by the World Conservation Union (IUCN) and The Nature Conservancy (TNC).

“Coral Reef Resilience and Resistance to Bleaching” and “Managing mangroves for Resilience to Climate Change” list the range of human threats to the ecology, and the risks posed by climate change.

“The two reports give a clear message,” says Carl Gustaf Lundin, head of the IUCN Global Marine Programme.

“While we cannot stop climate change in the short term, we can help tropical marine ecosystems survive,” he adds.

“If reef managers and politicians follow the measures proposed in these publications, we may be able to reverse the trends.”

Warming seas

Reefs are particularly sensitive to climate change because they bleach easily if there are changes to sea surface temperatures (SSTs), the groups warn.

Corals get their colour from tiny single-cell plants – zooxanthellae – which provide for the reef-building creatures, the polyps.

If there is an increase in SST for a prolonged period, the zooxanthellae are driven away, the coral loses its colour, the polyps lose their food and the reef is weakened.

The reefs then become more vulnerable to other threats, such as: overfishing; pollution; creatures that eat them; sedimentation from storm surges and snorkellers; and coastal developments.

Sometimes called “the tropical rainforests of the ocean”, reefs only cover 0.2% of the world’s sea-floor, but contain an estimated 25% of marine species.

They also provide a source of income and food for millions of people, the authors say, delivering about $30bn (