Sunscreen: Protects Skin, Harms Coral

June 16, 2008 06:58 AM
by Sarah Amandolare
Ingredients in sunscreen that fend off UV rays cause bleaching and death of coral reefs, but environmentally friendly swimming is still possible, experts say.

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The San Francisco Gate reports that in addition to harming coral, ingredients in sunscreen also appear to build up in other forms of aquatic life, including fish in lakes and rivers. Other personal care products, such as lotions, perfumes and medications also show up in bodies of water.

The trouble is caused by coral’s symbiosis with a type of algae called zooxanthellae, which needs UV light to live. Once in contact with sunscreen, the algae can no longer absorb light, in turn causing a latent virus to surface and kill the plant. Coral, dependent on algae for nourishment, then loses its color and appears bleached.

According to Christian Daughton, chief of the U.S. Environmental Protection Agency’s environmental chemistry branch at the National Exposure Research Laboratory in Las Vegas, “Once the coral bleaches, it can’t really survive.”

Even low levels of sunscreen ingredients, “a paraben preservative and three types of UV filters,” killed algae within four days, according to Environmental Science and Technology, which reported on the initial study of coral in January 2008.

The sunscreen threat to coral exacerbates an already dire situation. A team of marine scientists said in 2007 that coral reefs could disappear entirely by 2050 due to global warming.

However, beach-goers can do their part by using biodegradable sunscreens, which have been used for years in Mexico, Florida and Hawaii, according to Reuters.

Headline Links: How sunscreen kills coral

Background: The threat posed by global warming

Related Topics: Biodegradable sunscreen and soft coral

Reference: The initial study by Italian researchers


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