Effects of ozone depletion on aquatic ecosystems

Abstract

The single most important form of energy on our planet is solar radiation. It has been estimated that 0.1% of the incident energy is converted into organic material in the process of photosynthesis carried out by higher plants and photosynthetic microorganisms. During this process terrestrial plants incorporate about 400 Gt of carbon dioxide into biomass. This huge amount of biomass production, however, is exceeded by photosynthetic aquatic microorganisms, the phytoplankton, most of which spreads out in the photic zone in the oceans. Piled together, the total amount of CO₂ would fill a freight train, the length of which would encircle the equator about 380 times (Hader et al, 1989). The marine phytoplankton communities represent by far the largest ecosystem on earth (Schneider, 1989). Any, even small losses in the productivity of the phytoplankton due to increased UV-B radiation as a consequence of the partial ozone destruction by man-made gaseous pollutants such as chlorinated fluorocarbons (CFCs) would have drastic effects on the ecosystem itself and on the following links in the biological food chain, including humans who depend on a functioning phytoplankton ecosystem in many ways (Hader et al, 1989).