Assessing sublethal effects of ultraviolet radiation in juvenile rainbow trout (Oncorhynchus mykiss)

This paper presents a method for assessing sublethal effects of ultraviolet radiation in fish. The method is based on the assumption that UV-B exposure is stressful to fish. We measured oxygen consumption in UV-B-irradiated rainbow trout juveniles using a UV-transparent respirometer chamber. In addition, we simultaneously monitored fish behavior by videotaping. We found a direct relationship between UV-B irradiance and the percentage increase in oxygen consumption. Increased swimming activity and restless behavior were also noted under UV-B irradiation. The actual mechanisms by which fish perceive UV radiation and a behavioral reaction is triggered are unknown. Based on the present study, a response to UV-A irradiation cannot be ruled out.