title: Fluence rate or cumulative dose? Vulnerability of larval northern pike (Esox lucius) to ultraviolet radiation.
abstract: Newly hatched larvae of northern pike were exposed in the laboratory to four fluence rates of ultraviolet radiation (UVR; 290-400 nm) over three different time periods, resulting in total doses ranging from 3.0 +/- 0.2 to 63.0 +/- 4.4 kJ.m(-2). Mortality and behavior of the larvae were followed for 8-12 days, and growth measured at the end of the experiment. Also, the principle of reciprocity-that the UVR-induced mortality depends on the cumulative dose, independent of fluence rate-was tested. Fluence rates higher than 1480 +/- 150 mW.m(-2) caused mortality and growth retardation. The highest fluence rate (3040 +/- 210 mW.m(-2)) caused 100% mortality in 5 days. All fluence rates caused behavioral disorders, which led to death at fluence rates higher than 1480 mW.m(-2). Reciprocity failure occurred with the lowest and highest dose (550 +/- 45 and 3040 +/- 210 mW.m(-2), respectively). The results show that fluence rate is of primary importance when assessing the UVR-related risk.
authors.affiliation: Department of Biological and Environmental Sciences, University of Jyväskylä, Finland. eevehnia@cc.jyu.fi
authors.forename: E-R
authors.initials: ER
authors.lastname: Vehniäinen
authors.forename: Jani M
authors.initials: JM
authors.lastname: Häkkinen
authors.forename: Aimo O J
authors.initials: AO
authors.lastname: Oikari
mesh_terms: D000818:Animals; D017859:Esocidae / Q000254:growth & development / Q000502:physiology; D007814:Larva / Q000254:growth & development / Q000502:physiology / Q000528:radiation effects*; D008124:Locomotion / Q000528:radiation effects; D018462:Photobiology; D011829:Radiation Dosage; D011836:Radiation Tolerance; D013550:Swimming; D014466:Ultraviolet Rays / Q000009:adverse effects*