Coral-list post by Cheryl Woodley

I’d like to bring to your attention a new study published yesterday in the
journal *Archives of Environmental Contamination and Toxicology* showing
that a chemical widely used in personal care products such as sunscreen,
poses an ecological threat to corals and coral reefs and threatens their
existence.

Oxybenzone (also known as BP-3; Benzophenone-3) is found in over 3,500
sunscreen products worldwide, and pollutes coral reefs from swimmers
wearing sunscreens and through wastewater discharges from municipal sewage
outfalls and from coastal septic systems. Between 6,000 and 14,000 tons of
sunscreen lotion are emitted into coral reef areas each year, much of which
contains between one and 10% oxybenzone. The authors estimate that this
puts at least 10% of global reefs at risk of high exposure, based on reef
distribution in coastal tourist areas.

Toxicopathological effects of the sunscreen UV filter, oxybenzone on coral
planulae demonstrates that exposure of coral planulae (baby coral) to
oxybenzone, produces gross morphological deformities, damages their DNA,
and, most alarmingly, acts as an endocrine disruptor. The latter causes the
coral to encase itself in its own skeleton leading to death.

These effects were observed as low as 62 parts per trillion, the equivalent
to a drop of water in six and a half Olympic-sized swimming pools

Measurements of oxybenzone in seawater within coral reefs in Hawaii and the
U.S. Virgin Islands found concentrations ranging from 800 parts per
trillion to 1.4 parts per million. This is over 12 times higher than the
concentrations necessary to impact on coral

Article
Archives of Environmental Contamination and Toxicology, pp 1-24

First online: 20 October 2015

Toxicopathological Effects of the Sunscreen UV Filter, Oxybenzone (Benzophenone-3), on Coral Planulae and Cultured Primary Cells and Its Environmental Contamination in Hawaii and the U.S. Virgin Islands
C. A. Downs, Esti Kramarsky-Winter, Roee Segal, John Fauth, Sean Knutson, Omri Bronstein, Frederic R. Ciner, Rina Jeger, Yona Lichtenfel and 5 more

UV light on corals

Special thanks to Coral-list@noaa.gov

$39.95 / €34.95 / £29.95 *

* Final gross prices may vary according to local VAT.
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Abstract

Benzophenone-3 (BP-3; oxybenzone) is an ingredient in sunscreen lotions and personal-care products that protects against the damaging effects of ultraviolet light. Oxybenzone is an emerging contaminant of concern in marine environments—produced by swimmers and municipal, residential, and boat/ship wastewater discharges. We examined the effects of oxybenzone on the larval form (planula) of the coral Stylophora pistillata, as well as its toxicity in vitro to coral cells from this and six other coral species. Oxybenzone is a photo-toxicant; adverse effects are exacerbated in the light. Whether in darkness or light, oxybenzone transformed planulae from a motile state to a deformed, sessile condition. Planulae exhibited an increasing rate of coral bleaching in response to increasing concentrations of oxybenzone. Oxybenzone is a genotoxicant to corals, exhibiting a positive relationship between DNA-AP lesions and increasing oxybenzone concentrations. Oxybenzone is a skeletal endocrine disruptor; it induced ossification of the planula, encasing the entire planula in its own skeleton. The LC50 of planulae exposed to oxybenzone in the light for an 8- and 24-h exposure was 3.1 mg/L and 139 µg/L, respectively. The LC50s for oxybenzone in darkness for the same time points were 16.8 mg/L and 779 µg/L. Deformity EC20 levels (24 h) of planulae exposed to oxybenzone were 6.5 µg/L in the light and 10 µg/L in darkness. Coral cell LC50s (4 h, in the light) for 7 different coral species ranges from 8 to 340 µg/L, whereas LC20s (4 h, in the light) for the same species ranges from 0.062 to 8 µg/L. Coral reef contamination of oxybenzone in the U.S. Virgin Islands ranged from 75 µg/L to 1.4 mg/L, whereas Hawaiian sites were contaminated between 0.8 and 19.2 µg/L. Oxybenzone poses a hazard to coral reef conservation and threatens the resiliency of coral reefs to climate change.