Effects of the sunscreen ultraviolet filter oxybenzone (benzophenone-3) on the seagrass Posidonia oceanica (L.) Delile and its associated N2 fixers

• Published in: The Science of the total environment Vol. 918; p. 170751
• Main Authors: García-Márquez, Manuela Gertrudis, Rodríguez-Castañeda, José Carlos, Agawin, Nona S.R.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25-03-2024
• Subjects: Alkaline phosphatase; Contaminant; Leaf chlorophyll; Mediterranean; Nitrogen fixation; Oxidative damage; Nitrogen fixation; Mediterranean; Alkaline phosphatase; Oxidative damage; Contaminant; Leaf chlorophyll
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2024.170751

Oxybenzone/benzophenone-3 (BP-3) is one of the most detrimental organic ultraviolet filters for marine biota, leading to legislative measures banning its presence in commercial sunscreen formulations of several countries. It remains poorly explored how this contaminant is currently threatening the persistence of critical ecosystems for conservation in the Mediterranean, such as Posidonia oceanica meadows, but it is essential for promoting sustainable coastal tourism. Our investigation aimed to determine the effects of BP-3 on P. oceanica under a short-term laboratory setup, recreating summer conditions while testing three environmentally relevant concentrations for Mallorca, Spain (minimum: 53.6 ng L−1, maximum: 557.5 ng L−1 and increased: 1115 ng L−1) and a control (0 ng L−1). Primary productivity was unaffected by the treatments, however, a reduction in leaf chlorophyll content and nitrogen fixation activity associated with rhizomes was evidenced under BP-3 addition. This may be related with oxidative damage, as reactive oxygen species production and catalase activity in P. oceanica leaves were the highest even at minimum BP-3 concentrations. Alkaline phosphatase rates showed inverted trends between old leaves and rhizomes, being enhanced in the former under BP-3 addition and reduced in the latter. These results are of great relevance for the future management of P. oceanica meadows, elucidating that even minimum concentrations of BP-3 reported in coastal waters of Mallorca can induce elevated levels of oxidative stress in the seagrass, that lead to impairments in its photosynthetic pigments production and supply of essential nutrients through belowground tissues.
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•BP-3 concentrations in coastal waters may induce potentially harmful effects in P. oceanica through oxidative stress.•Leaf chlorophyll production of P. oceanica declined under BP-3 addition, even at minimum levels of the contaminant.•BP-3 not only penetrates the rhizomes of P. oceanica but can restrict the N2 fixation associated with this tissue.