title: Cell size dependence of additive versus synergetic effects of UV radiation and PAHs on oceanic phytoplankton.
abstract: Polycyclic Aromatic Hydrocarbons' (PAHs) toxicity is enhanced by the presence of ultraviolet radiation (UVR), which levels have arisen due to the thinning of the ozone layer. In this study, PAHs' phototoxicity for natural marine phytoplankton was tested. Different concentrations of a mixture of 16 PAHs were added to natural phytoplankton communities from the Mediterranean Sea, Atlantic, Arctic and Southern Oceans and exposed to natural sunlight received in situ, including treatments where the UVR bands were removed. PAHs' toxicity was observed for all the phytoplankton groups studied in all the waters and treatments tested, but only for the pico-sized group a synergetic effect of the mixture and UVR was observed (p=0.009). When comparing phototoxicity in phytoplankton from oligotrophic and eutrophic waters, synergy was only observed at the oligotrophic communities (p=0.02) where pico-sized phytoplankton dominated. The degree of sensitivity was related to the trophic degree, decreasing as Chlorophyll a concentration increased.
authors.affiliation: Department of Global Change Research, IMEDEA (CSIC-UIB) Instituto Mediterráneo de Estudios Avanzados, Miquel Marqués 21, 07190 Esporles, Illes Balears, Spain. pecheveste@imedea.uib-csic.es
authors.forename: Pedro
authors.initials: P
authors.lastname: Echeveste
authors.forename: Susana
authors.initials: S
authors.lastname: Agustí
authors.forename: Jordi
authors.initials: J
authors.lastname: Dachs
mesh_terms: D059001:Aquatic Organisms / Q000166:cytology / Q000187:drug effects* / Q000528:radiation effects; D001267:Atlantic Ocean; D008522:Mediterranean Sea; D010839:Phytoplankton / Q000166:cytology / Q000187:drug effects* / Q000528:radiation effects; D011084:Polycyclic Aromatic Hydrocarbons / Q000633:toxicity*; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical