Sunscreen

Sunscreen and Coral

Sunscreen and reefs

It has been proven that sunscreen and other personal care cosmetics are potentially harmful to marine environments in terms of bioaccumulation of UV filters in animals and photodegradtion, which turns sunscreen agents into toxic by-products. They can be so harmful that they have been banned in certain high tourists areas, but there had been no studies on the effect on reefs. In a study headed by faculty at Polytechnic University of the Marche, Ancona, Italy, researchers measured the effect of sunscreen on reefs from 2003-2007. A team conducted experiments adding aliquots of sunscreens and other common ultraviolet filters contained in sunscreen to the coral branches from several different tropical areas covering the Pacific, Atlantic, Indian, and Pacific Ocean plus the Red Sea. Then, they observed the zooxanthellae for viral infection. [13] Through these experiments on site and in the laboratory, it was determined that sunscreens cause complete and rapid bleaching of hard corals, even at extremely low concentrations. This negative effect is the result of organic ultraviolet filters, which cause zooxanthellae with infections to enter a lytic viral cycle. By fostering this viral infection, sunscreens could play a influential role in coral bleaching in areas exposed to high levels of human recreation. [13] It was calculated that 10% of the reefs in the world could be threatened by sunscreen induced bleaching. This calculation is a result of the estimations that in tropical countries somewhere between 16,000 and 25,000 tons of sunscreens will be applied, and of that amount at least 25% will be washed off in the ocean. This leads to a potential release of 4,000–6,000 tons/year of sunscreen in reef areas. This number will only increase as humans continue to increase our use of the reefs. [13]