Effects of increased solar ultraviolet radiation on aquatic ecosystems

Aquatic ecosystems supply humans with vast amounts of food, primarily in the form fo finfish, shellfish and seaweed. More than 30 of the world's animal protein for human consumption comes from the sea, and in many countries, particularly the developing countries, this percentage is significantly higher. As a result, it is important to know how increased levels of exposure to solar UV-B radiation (280-315 nm) might affect the productivity of aquatic systems. In addition, the oceans plan a key role with respect to global warming. Marine phytoplankton are a major sink for atmospheric carbon-dioxide, and they have a decisive role in the development of future trends of carbon dioxide concentrations in the atmosphere. The relative importance of the net uptake of carbon dioxide by the biological pump in the ocean and by the terrestrial biosphere is a topic of much current research. Phytoplakton for the foundation on which the very survival of aquatic food webs depends. Marine phytoplancton are not uniformly distributed throughout the oceans of the world. The highest concentrations are found at high latitudes while, with the exception of upwelling areas on the continental shelves, the tropics and subtropics have 10 to 100 times lower concentrations. In addition to nutrients, temperature, salinity and light availability, the high levels of exposure to solar UV-B radiation that normally occur within the tropics and subtropics may play a role in phytoplankton distribution