Ecotoxicological Effects of Cosmetic Formulas Containing Chemical and Mineral UV Filters on Seriatopora hystrix Fragments

Background: Over the last few years sunscreen products have been suspected to be harmful to corals, especially because of their putative negative impact on symbiotic microalgae housed by these cnidarians. Previous publications reported that minerals or chemical UV filters could induce the release of microalgae from corals inducing their bleaching. The study of the ecotoxicity of finished cosmetic products containing these filters is important. Objectives: We sought to assess ex vivo the toxicity of five emulsions containing UV-filters on coral cuttings of Seriatopora hystrix. Materials and Methods: Coral cuttings were put in contact with 5 different emulsions containing UV-filters. The toxicity readout was the ability to induce polyp retraction and/or fragment bleaching of the coral cuttings of Seriatopora hystrix. Results: In our experimental conditions, none of the five tested formulas neither induced any significant polyp retraction nor triggered fragment bleaching of the coral. Conclusions: The five tested emulsions containing UV-filters did not modify coral cuttings. In vivo, larger tests are necessary to verify the results of this ex vivo pilot study.