Comparative sensitivity of rainbow trout and two threatened salmonids, Apache trout and Lahontan cutthroat trout, to ultraviolet-B radiation
Citation
Edward E Little, and David L Fabacher, Comparative sensitivity of rainbow trout and two threatened salmonids, Apache trout and Lahontan cutthroat trout, to ultraviolet-B radiation: .
Summary
Elevated levels of ultraviolet-B (UV-B) radiation resulting from stratospheric ozone depletion may cause harmful effects in freshwater fishes. We investigated the effects of simulated solar UV-B radiation on rainbow trout (Oncorhynchus mykiss) and two threatened salmonids, Apache trout (Oncorhynchus apache) and Lahontan cutthroat trout (Oncorhynchus clarki henshawi). Lahontan cutthroat trout and Apache trout are threatened because of habitat loss and competition from non-native fishes. These species inhabit clear-water alpine habitats and may be at risk from elevated levels of UV-B radiation. In the laboratory, fish received daily 5-h exposures to UV-B radiation during a 16-h photoperiod. A solar simulator generated a total UV-B (290 [...]
Summary
Elevated levels of ultraviolet-B (UV-B) radiation resulting from stratospheric ozone depletion may cause harmful effects in freshwater fishes. We investigated the effects of simulated solar UV-B radiation on rainbow trout (Oncorhynchus mykiss) and two threatened salmonids, Apache trout (Oncorhynchus apache) and Lahontan cutthroat trout (Oncorhynchus clarki henshawi). Lahontan cutthroat trout and Apache trout are threatened because of habitat loss and competition from non-native fishes. These species inhabit clear-water alpine habitats and may be at risk from elevated levels of UV-B radiation. In the laboratory, fish received daily 5-h exposures to UV-B radiation during a 16-h photoperiod. A solar simulator generated a total UV-B (290 to 320 nm) irradiance up to 357 mu W/cm super(2), simulating ambient mid-latitude summer irradiance. Lahontan cutthroat trout were the most sensitive of the three species to UV-B radiation, showing a characteristic sunburn pattern on the dorsal skin within 2 d, followed by significant fungal infection within 3 d, and then mortality within 6 d of exposure. Rainbow trout developed similar patterns of pigmentation and fungal infection but survived the exposure. Few Apache trout developed changes in pigmentation, and they did not develop fungal infection. Our results indicate that natural populations of Lahontan trout and rainbow trout exposed to UV-B radiation may be at risk of fungal infection.
Published in Advances in Limnology, in 1994.