鈥淣O-TAKE zones鈥� might protect coral reefs against overfishing, but no signpost can counter the effects of global warming.
Coral bleaching 鈥� the loss of colour when coral tissue expels its symbiotic algae 鈥� is triggered by very high ocean temperatures and can be fatal. Climate change might make it more common.
To look at the effect of 1998鈥檚 global coral bleaching, Nicholas Graham at Newcastle University, UK, and his team studied reef fish at 66 sites in the Indian Ocean, including no-take zones that ban fishing.
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鈥淭hese areas weren鈥檛 designed to protect against bleaching,鈥� says Graham, but they were expected to protect enough fish species to help 鈥渢he reef to recover鈥�. However, the team found the same extent of coral loss in protected and unprotected areas, and saw no difference in the time the reefs took to recover (PLoS One, ).
鈥淣o-take areas were expected to protect enough fish species to help coral reefs recover鈥�
Some reefs fared better than others, however. Pockets of the Seychelles, which are surrounded by deep water, are recovering fast. The area鈥檚 strong currents are 鈥減robably flushing the reefs and removing any excess sediment, which can discourage coral from settling鈥�, says Graham.
DeeVon Quirolo of charity Reef Relief says expanding protected areas is not the answer. Reducing pollution, such as agricultural run-off, 鈥渨ill have more bearing on the ultimate health of coral reefs than drawing lines in the water鈥�, she says.
