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Researchers from Utrecht ľ�ϸ���Ӱ�� and Florida State ľ�ϸ���Ӱ�� are studying the protective cover that coral reefs provide to coastal areas. Coral health might influence their ability to protect the coast from wave impact. With rising sea levels and declining coral cover, there is an urgent need for scientific research.

Coral reefs are some of Earth's most beautiful environments. And they are useful too – not only do they support enormous biodiversity, they also protect coastlines from wave impact. However, we do not exactly know the extent to which they do this. Nor do we know how much this protection diminishes when coral dies. Dr Jaap Nienhuis from Utrecht ľ�ϸ���Ӱ�� and of Florida State ľ�ϸ���Ӱ�� study the coral reefs along the coast of Jamaica. They feed their results into a computer model to investigate the relationship between coral health and wave energy dissipation.

Armed with underwater cameras and wave gauges, Nienhuis and Daly work in the sea off Jamaica. They spend twelve hours a day collecting data, which they then process in the evening. “These are long days”, Nienhuis says, “but to be able to work in such an environment is extremely rewarding". The researchers measure the extent and state of the coral reefs in Jamaica. “There is an interaction between the reefs and the waves", he continues. “The more coral there is, the more the motion of the waves is slowed. Wave energy reaching the coast is decreased: large waves cause coastal erosion, which leads to the beach slowly disappearing.”

Coral reef health has been declining for decades now across the globe, which is not only a disaster for biodiversity but also, as we are seeing, has a major impact on coastal areas. Overfishing, global warming and deforestation all contribute to the deterioration of coral. It dies, becomes bleached, or simply disappears. “The coral was in very bad shape in the 1990s", Nienhuis explains, “but when we were in the field this year, we already saw improvements. In areas where fishing has been prohibited, the coral is gradually coming back to life.”

The scientists have now reached the stage where they can process their data in a computer model. “This model allows us to calculate the effect of the growth or decline of coral reefs on the coast, at least as far as Jamaica is concerned. We hope to be able to use it for other coastal areas too in the future”, Nienhuis concludes.