Phytoplankton responses to human impacts at different scales

This book: Deals with eutrophication impact on ecosystem functioning with a different focus and broader perspective. Takes into account the effects of multiple stressors on microalgal assemblages. Includes specific contributions on the autoecology and taxonomy of dinoflagellates and cyanobacteria. Features examples of applications of the morphology-, morpho-functional and functional groups (FG), (MFG) and (MBFG) Phytoplankton responses to human impact at different scales provides a state-of-the-art review of changes in the phytoplankton assemblages determined by human alterations of lakes and rivers. A wide spectrum of case studies describe the effects due to eutrophication and climate change, as well as other impacts connected with watershed management, hydrological alterations and introduction of non-indigenous species. The volume also includes two wide reviews on planktonic coccoid green algae and planktic heterocytous cyanobacteria. This book is addressed to ecologists and scientists involved in phytoplankton ecology and taxonomy. Many case studies provide a sound scientific basis of knowledge for a wise management of water bodies

Terminal electron transport system (ETS)-activity in the sediment of Lake Balaton, Hungary

Terminal electron transport system (ETS)-activity of the sediment and plankton of Lake Balaton, the largest shallow lake of Central Europe was measured by tetrazolium-reduction biweekly during 1989–1990 and in the spring of 1991. Sediment proved to be enzymatically active to 30-35 cm down in the hypertrophic Keszthely Bay and to 15–20 cm down in the meso-eutrophic Siófok Basin. Sediment ETS-activity exceeded planktonic activity 15 to 24 fold. The total activity m−2 showed one or two order of magnitude higher respiratory potential in Lake Balaton than needed for complete oxidation of the planktonic primary production; most of this potential was detected in the upper 3–5 cm sediment layer in springs. Incubations of cell-free homogenates of sediment bacteria showed that ETS remains active days after death of organisms at low temperature. Accumulated postmortem ETS-activity derived from the benthic diatoms, bacteria, plankton deposit and dead summer macrophytes seems to be responsible for the high ETS-activity of the sediment in the warming periods in springs. These enzyme fractions may contribute to the rapid oxidation of the alkaline, well-aerated lake