title: Effects of UVB radiation on grazing of two cladocerans from high-altitude Andean lakes.
abstract: Climate change and water extraction may result in increased exposition of the biota to ultraviolet-B radiation (UVB) in high-altitude Andean lakes. Although exposition to lethal doses in these lakes is unlikely, sub-lethal UVB doses may have strong impacts in key compartments such as zooplankton. Here, we aimed at determining the effect of sub-lethal UVB doses on filtration rates of two cladoceran species (Daphnia pulicaria and Ceriodaphnia dubia). We firstly estimated the Incipient Limiting Concentration (ILC) and the Gut Passage Time (GPT) for both species. Thereafter we exposed clones of each species to four increasing UVB doses (treatments): i) DUV-0 (Control), ii) DUV-1 (0.02 MJ m2), iii) DUV-2 (0.03 MJ m2) and iv) DUV-3 (0.15 MJ m2); and estimated their filtration rates using fluorescent micro-spheres. Our results suggest that increasing sub-lethal doses of UVB radiation may strongly disturb the structure and functioning of high-altitude Andean lakes. Filtration rates of D. pulicaria were not affected by the lowest dose applied (DUV-1), but decreased by 50% in treatments DUV-2 and DUV-3. Filtration rates for C. dubia were reduced by more than 80% in treatments DUV-1 and DUV-2 and 100% of mortality occurred at the highest UVB dose applied (DUV-3).
authors.affiliation: Unidad de Limnología y Recursos Acuáticos, Universidad Mayor de San Simón, Cochabamba, Bolivia.|Division of Water Resources Engineering, Lund University, Lund, Sweden.
authors.forename: Carla Eloisa
authors.identifier: http://orcid.org/0000-0002-2200-5991
authors.initials: CE
authors.lastname: Fernández
authors.affiliation: Unidad de Limnología y Recursos Acuáticos, Universidad Mayor de San Simón, Cochabamba, Bolivia.
authors.forename: Danny
authors.initials: D
authors.lastname: Rejas
mesh_terms: D000531:Altitude; D000818:Animals; D059001:Aquatic Organisms / Q000502:physiology / Q000528:radiation effects; D033361:Cladocera / Q000502:physiology / Q000528:radiation effects*; D057231:Climate Change; D003621:Daphnia / Q000502:physiology / Q000528:radiation effects*; D004063:Digestion / Q000502:physiology / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D004435:Eating / Q000502:physiology / Q000528:radiation effects; D060106:Lakes; D014466:Ultraviolet Rays / Q000009:adverse effects*