Climate change and coral spawning

What's the point of setting up marine reserves to protect coral reefs from pollution, ship groundings and overfishing if climate change could cause far more damage? A study published this week in London in Proceedings of the Royal Society B provides the answer.

For decades researchers have known that corals synchronise their release of eggs and sperm into the water but were unsure of how and why. Robert van Woesik, a biologist at the Florida Institute of Technology, explains why corals spawn for just a few nights in some places but elsewhere string out their love life over many months.

The study shows that corals spawn when regional wind fields are light. When it is calm the eggs and sperm have the chance to unite before they are dispersed. Corals off the coast of Kenya have months of light winds so they can reproduce for much of the year. On the Great Barrier Reef in Australia, calm weather is short-lived and the coral reproductive season is brief.

The results of the study are critically important for effective reef conservation.

According to van Woesik: "Coral reproduction is a very local event. This means local conservation efforts will maximise reproductive success and give reef systems a chance to adapt to global climate change."

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