title: UV-B exposure increases acute toxicity of pentachlorophenol and mercury to the rotifer Brachionus calyciflorus.
abstract: Adverse biological effects of ultraviolet-B (UV-B) radiation have been well documented for phytoplankton and zooplankton in both marine and freshwater ecosystems. However, investigations of interactions between UV-B and anthropogenic toxicants have focused primarily on the chemical interactions between UV-B and the toxicant. Here we investigate the potential for UV-B to increase the sensitivity of the rotifer Brachionus calyciflorus to either acute pentachlorophenol (PCP) or mercury toxicity, independent of UV-B effects on these toxicants. UV-B increased the toxicity of PCP and mercury to B. calyciflorus as much as five-fold, depending on duration of UV-B exposure and toxicant concentration. Reductions in the LC(50) of up to 60% were also seen for both toxicants. UV-B alone effectively eliminated B. calyciflorus reproduction and reduced ingestion by up to 90%. These results demonstrate the potential for UV-B to increase rotifer sensitivity to anthropogenic stressors independent of photochemical reactions with toxicants.
authors.affiliation: Georgia Institute of Technology, School of Biology, Atlanta, GA 30332-0230, USA. gt6027b@prism.gatech.edu
authors.forename: B L
authors.initials: BL
authors.lastname: Preston
authors.forename: T W
authors.initials: TW
authors.lastname: Snell
authors.forename: R
authors.initials: R
authors.lastname: Kneisel