Human presence in Antarctica has grown significantly in the last decades, receiving ~4,500 scientists and technical staff at research stations and ~75,000 tourists annually. To protect from the detrimental effects of ultraviolet radiation (UVR), visitors are prone to use sunscreens, which inevitably end up released into the environment. The goal of this study was to evaluate the effects of two of the most common organic UV filters, oxybenzone and octocrylene, on natural microbial communities of Fildes Bay (King George Island), regarding changes in their community composition, cell abundance, photosynthetic efficiency (Ω), metabolism, as well as the nutrients availability to them. Overall, oxybenzone had a greater impact than octocrylene, with a mean inhibitory concentration on the whole phytoplankton community of 5.9 and 4.0 mg L-1 in the absence or presence of UVR, respectively, being >50 mg L-1 in the case of octocrylene. However, the smallest microorganisms were already affected by both sunscreens at 0.5 mg L-1, especially in the presence of UVR. Nutrients availability increased as the concentrations of both chemicals augmented, above all with oxybenzone and UVR. Both UV filters reduced both primary production, in the case of oxybenzone reducing Ω by a 30%; and respiration, more pronounced with oxybenzone in the absence of UVR and octocrylene on its presence. Although these results point to a higher toxicity of oxybenzone than octocrylene, both UV filters should be considered for regulation according to the Protocol on Environmental Protection to the Antarctic Treaty.

Primary Presenter: Pedro Echeveste, Universidad de las Islas Baleares (p.echeveste@uib.eu)

Authors:

Maritza Fajardo, Universidad de Antofagasta  (maritzafajardo89@gmail.com)

Katiuska Huapaya, Universidad de Antofagasta  (katiuska.huapaya.mora@ua.cl)

Marcela Cornejo-D'Ottone, Pontificia Universidad Católica de Valparaíso  (marcela.cornejo@pucv.cl)

Aurore Regaudie de Gioux, Institut Français de Recherche pour l'Exploitation de la Mer  (aurore.regaudie.de.gioux@ifremer.fr)

Víctor Fernández-Juárez, University of Copenhagen  (victor.fj@bio.ku.dk)

Lasse Riemann, University of Copenhagen  (lriemann@bio.ku.dk)