The aim of the project is to study the effects of UV-B radiation on marine phytoplankton. Investigations have shown that UV-B radiation affects growth, motility, nitrogen metabolism, photosynthetic activity etc. and there is growing concern that in addition to a decrease in biomass production there may be changes in the species composition. The main objective is to investigate the sensitivity of different, ecologically important, marine phytoplankton species to UV-B radiation, in order to calculate the effects of predicted ozone depletion.
The spectral distribution and penetration of solar radiation into the water column has been measured in several water types in the Baltic Sea, North Sea and the Mediterranean. A device was developed to sample the water column in order to study vertical migrations and distributions of phytoplankton. Effects of solar UV-B as well as the synergistic and antagonistic roles of other wavelength bands of solar radiation have been determined for photosynthesis in the water column for a number of ecologically important phytoplankton species. Microspectroscopic techniques have been applied to a number of ciliates to study photoreceptor damage.
The basic mechanisms for phytoplankton orientation strategies will be studied in motile microorganisms. These investigations will be carried out using a real time image analysis system. Several software packages will be developed to meet the specific needs of organisms with a wide range of behavioral and structural characteristics.
The effects of UV-B radiation will be determined for the selected phytoplankton organisms. The basic research strategy is to investigate the behavior under natural solar radiation at suitable locations in Sweden, Italy and Germany. These experiments will be backed up by investigations under defined artificial UV-B light sources in the laboratory using standard conditions in order to quantify the effects and to determine the specific UV-B related inhibition as well as the synergistic effects of UV-A and visible radiation components.
The vertical stratification and diurnal movements of the organisms will be studied in field experiments under natural conditions. The effects of ambient and enhanced solar UV-B irradiation on the ability of the phytoplankton organisms to adapt to the constantly changing light conditions within the water column will be determined.
The molecular mechanisms of UV-B effects will be determined. For this purpose the primary UV targets will be identified in a number of ecologically important model systems. These biochemical UV effects will be analyzed on the protein level. In addition, changes in the pigmentation will be studied using spectroscopic methods and will be extended to the cellular and subcellular level using microspectroscopic techniques in the Italian laboratory. Finally, the biochemical and spectroscopic analysis of the UV-B dependent damage in the cells will be carried out.
Funding SchemeCSC - Cost-sharing contracts
221 00 Lund