Exposure to Ultraviolet-B radiation
Exposure to high levels of Ultraviolet-B (UV-B) radiation can have a range of harmful
effects on living organisms, and damage to the ozone layer has caused an increase in
UV-B radiation of up to 50% in some alpine areas (Schindler et al., 1996). Although the
ozone layer protects both terrestrial and aquatic ecosystems from much of the sun’s UVB
radiation, some aquatic animals may be more vulnerable to the radiation that reaches
the Earth’s surface because they have historically been afforded a high level of protection
by natural characteristics of the waters they inhabit (Williamson, 1995). UV-B radiation
generally only penetrates the top layer of water bodies; the depth of UV-B penetration
depends on water clarity and on the concentrations of dissolved organic carbon
(DOC) and/or chromophoric dissolved organic matter (CDOM), which are derived from
the breakdown of plant materials or dead organisms.