Could your sunscreen kill coral?

Friday August 1, 2008

Up to 10% of coral reefs worldwide are threatened by bleaching caused by chemicals in sunscreens, according to Italian scientists.

Between 4,000 and 6,000 tonnes of sunscreen wash off swimmers annually in oceans worldwide. Many popular brands contain ingredients that stimulate viruses in the algae, known as zooxanthellae, that live within the corals, say researchers.

The scientists looked at the effect of sunscreen on corals in the Pacific, Atlantic and Indian oceans, and the Red Sea.

They found that four sunscreen chemicals – parabens, cinnamates, benzophenones and a camphor derivative – cause the viruses to replicate until their algae hosts explode, spilling virus particles into the surrounding seawater, where they can infect neighbouring coral communities. Without the algae, the coral turns white and often dies.

The researchers suggest that tourists use sunscreens that break down in the water, or that are free of parabens and the other chemicals identified as the problem.

(Mark Rowe, Geographical Magazine, May 2008)



Illustration of Red tooth triggerfish