Detailed project information

The research proposed here focuses on competition among species and strains of cyanobacteria in aquatic ecosystems, with special attention ot the importance of the physiology of these organisms. Superior competitors in particular environments generally have a variety of morphological and physiological adaptations that optimally match prevailing conditions. By consideration of these characteristics, can we understand why particular species dominate in particular ecosystems? Two lines of research are emphasized in this proposal, being (1) the role of buoyancy regulation and (2) the role of cyanotoxins in competition among colony-forming cyanobacterial species and strains. Buoyancy, provided by gas-filled vesicles in the cells, plays an important role in competition for light, as vertical distributions of cyanobacteria in lakes are dependent on both buoyancy and water-mixing. This first line of research aims to compare growth rates of different species of cyanobacteria under various physical conditions, using experimental and modelling approaches. The second line of research will improve understanding of competition between toxic and non-toxic strains. Specifically, cyanotoxins may have a physiological function or play a role as 'chemical weapons' in competition. A major strenght of the proposed research is that phytoplankton physiology is tightly linked to both theoretical ecology and molecular biology.