Ultraviolet Radiation and Phytoplankton Photosynthesis

The effect of present-day levels of ultraviolet radiation (290-320 nm) on14Cincorporation by natural phytoplankton populations was measured. There is a statistical relationship between dosage and reduction of14Cuptake. This effect could be detected throughout a significant portion of the euphotic zone, but the major effect is restricted to the upper portions of the euphotic zone. Overall, its effect on present-day estimates of oceanic production is minimal. Similarly, potential effects of elevated UV-B levels striking the surface of the sea, resulting from perturbations of the ozone layer, are restricted to the upper few meters of the water column.