Objective The aim of the proposed study is to assess community effects of toxicant fluxes in rivers. This can be achieved through a new methodology incorporating the large biological and chemical differences among European rivnrs. The fate and biological effectivity of toxicants in river system is supposed to be greatly affected by the concurrent loading with humics and various ions. To verify this, the speciation of metals, herbicides and PAH will be quantified. For metals, an experimental mobile voltametric instrument will be used together with sorption on chelating resins. Dialysis of isotope-labelled organic toxicants will be used to assess Sifferences in speciation of selected herbicides and PAH among rivers. When chemicals are present in biologically effective concentrations, these are likely to induce changes in the tolerance profile and species composition of communities. Such changes will be assessed in a selection of rivers, using natural communities of closely stacked micro-algae, Bacteria and microfauna, settled on sand and cobbles. Short-term metabolic tests will be used to describe the sensitivity of photosynthesis in algae (14 C-technique), DNA multiplication in bacteria (3H-thymidine method), and replication in eukaryotes (e.g.ciliates; adenine/thymidine method). Differences in tolerance to selected compounds (metals, herbicides, PAH), neasured with these physiological techniques will be compared with longterm community changes observed at river stations polluted with either a single type of contaminants or complex mixtures. Communities in artificial streams are used to verify questions raised in these field studies. Photometric alternatives for the isotope-based physiological techniques will be developed to allow wider application in future and a mobile Facility for in situ community tests will be created. The project will bring the biological and chemical approaches together into case studies of river pollution in northern, western and southern Burope. The complementary expertise of the partners allow an assessment of the consequences and risks of toxicant input in rivers that differs considerably from traditional methods based on a strategy of 'one species at a time' and 'one substance at a time'. The proposed research is likely to fulfil the needs of a growing Matchment oriented management of pollutants in Europe. KEYWORDS (max 10): river communities, speciation of toxicants, physiological endpoints, mesocosms, ecological risk-assessment Fields of science natural sciencesbiological sciencesmicrobiologybacteriologynatural sciencesbiological sciencesgeneticsDNAnatural sciencesearth and related environmental sciencesenvironmental sciencespollutionnatural sciencesbiological sciencesbotany Programme(s) FP4-ENV 2C - Specific programme of research and technological development in the field of environment and climate, 1994-1998 Topic(s) 02020102 - Risks to the environment Call for proposal Data not available Funding Scheme CSC - Cost-sharing contracts Coordinator Universiteit van Amsterdam Address 320,kruislaan 1098 SM Amsterdam Netherlands See on map EU contribution No data Participants (4) Sort alphabetically Sort by EU Contribution Expand all Collapse all GOETEBORG UNIVERSITY Sweden EU contribution € 0,00 Address 22b,carl skottsbergs gata 22b 413 19 Goeteborg See on map Other funding No data NATIONAL INSTITUTE OF PUBLIC HEALTH AND ENVIRONMENT Netherlands EU contribution € 0,00 Address 9,antonie van leeuwenhoeklaan 9 3721 BA Bilthoven See on map Other funding No data UNIVERSITAT DE BARCELONA Spain EU contribution € 0,00 Address 645,avinguda diagonal 645 08028 Barcelona See on map Other funding No data University of Joensuu Finland EU contribution € 0,00 Address 7,yliopistokatu 80101 Joensuu See on map Other funding No data
