The ecological significance of solar UV radiation on aquatic organisms

Abstract

Stratospheric ozone shields the Earth from much of the solar UV – B radiation which is the most biologically injurious component of sunlight. It is possible that both human technologies and natural events, such as reversal of the Earth's magnetic polarity, might lead to significant ozone reductions. The methodology of evaluation of the impact of an agent such as solar UV on organisms or ecosystems has not been firmly established and there has been little research in this area in the past. A new approach is proposed here. If solar UV were an important injurious factor in nature, then living organisms would be required to expend energy to cope with the solar UV exposure they receive. If organisms must specifically mitigate solar UV injury, then it would be expected that only a minimal tolerance would be achieved. We have quantitatively estimated exposure and tolerance of a number of aquatic organisms and find them to be remarkably similar.