The threat of UV-B exposure may be magnified by other human-induced stresses. For
example, CDOM derived from healthy, forested drainage basins is far more effective at
attenuating UV-B than colorless DOC from other sources (Schindler et al., 1996), and
deforestation decreases the input of CDOM to freshwaters. In addition, acidification
of lakes causes a decline in DOC concentrations, and thus UV-B radiation may actually
be responsible for many of the negative effects attributed to lake acidification (Schindler
et al, 1996).