title: Sunscreens cause coral bleaching by promoting viral infections.
abstract: BACKGROUND
  Coral bleaching (i.e., the release of coral symbiotic zooxanthellae) has negative impacts on biodiversity and functioning of reef ecosystems and their production of goods and services. This increasing world-wide phenomenon is associated with temperature anomalies, high irradiance, pollution, and bacterial diseases. Recently, it has been demonstrated that personal care products, including sunscreens, have an impact on aquatic organisms similar to that of other contaminants.
  
  
  OBJECTIVE
  Our goal was to evaluate the potential impact of sunscreen ingredients on hard corals and their symbiotic algae.
  
  
  METHODS
  In situ and laboratory experiments were conducted in several tropical regions (the Atlantic, Indian, and Pacific Oceans, and the Red Sea) by supplementing coral branches with aliquots of sunscreens and common ultraviolet filters contained in sunscreen formula. Zooxanthellae were checked for viral infection by epifluorescence and transmission electron microscopy analyses.
  
  
  RESULTS
  Sunscreens cause the rapid and complete bleaching of hard corals, even at extremely low concentrations. The effect of sunscreens is due to organic ultraviolet filters, which are able to induce the lytic viral cycle in symbiotic zooxanthellae with latent infections.
  
  
  CONCLUSIONS
  We conclude that sunscreens, by promoting viral infection, potentially play an important role in coral bleaching in areas prone to high levels of recreational use by humans.
authors.affiliation: Department of Marine Sciences, Faculty of Science, Polytechnic University of the Marche, Via Brecce Bianche, 60131 Ancona, Italy. r.danovaro@univpm.it
authors.forename: Roberto
authors.initials: R
authors.lastname: Danovaro
authors.forename: Lucia
authors.initials: L
authors.lastname: Bongiorni
authors.forename: Cinzia
authors.initials: C
authors.lastname: Corinaldesi
authors.forename: Donato
authors.initials: D
authors.lastname: Giovannelli
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Damiani
authors.forename: Paola
authors.initials: P
authors.lastname: Astolfi
authors.forename: Lucedio
authors.initials: L
authors.lastname: Greci
authors.forename: Antonio
authors.initials: A
authors.lastname: Pusceddu
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000187:drug effects* / Q000821:virology*; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D056890:Eukaryota / Q000187:drug effects*; D009792:Oceans and Seas; D013473:Sunscreening Agents / Q000633:toxicity*; D013559:Symbiosis
chemical_list: D013473:Sunscreening Agents