Sulphur and carbon data from the English Channel
Through the study of prokaryotic organisms within the vast array of pelagic microbes, the project BASICS aimed to determine the role of these microbes in the marine carbon and sulphur cycling process. The individual role of these microbes in the ecosystem as a whole can then be determined. The research has produced a comprehensive profile of the abiotic and biotic factors in the English channel. The environmental variables water temperature and salinity were recorded. In terms of the use of light as an energy source, the main biochemical elements in the phytoplankton were measured. These included concentrations of chlorophyll a and the chemical thought to be the naturally occurring plankton sunscreen, micosporine-like amino acid (MAA). In addition, fast repetition rate fluorometer (FRRF) measurements relating to photophysiology were recorded. Nano-, pico- and bacterioplankton were enumerated by using flow cytometry analysis. Finally, as a measurement of overall physiology of the plankton, levels of chemicals dimethylsulfoniopropionate (DMSP) and its breakdown product, dimethyl sulphide (DMS) were recorded. Both chemicals are thought to be important physiogically. For example, DMSP is thought to act as an osmolyte, preventing dehydration and a cryoprotectant to prevent damage from the cold. Furthermore, it may act as an antioxidant to help prevent UV damage. In the light of environmental changes expected in Europe's coastal waters, this study provides important background data on which to base further studies. Further detailed information on the carbon cycle promises to elucidate the process of eutrophication associated with microbial population increases. Furthermore, DMS is an important aerosol gas and a cloud droplet precursor. Its release from marine ecosystems therefore has important implications for climate change.
