Obiettivo To increase the understanding of chemical/geochemical processes influencing biological systems in aquatic mixing zones under severe dis-equilibrium conditions due to acidity vs. liming.Liming is extensively used in the restoration of acidified lakes and rivers, not only to increase the water pH and alkalinity, but also to reduce the amount of "toxic" aluminium species to fish and other sensitive organisms. Recent field studies have documented Al-toxicity to fish in the mixing zones between limed streams and acid tributaries. The conditions of severe chemical dis-equilibrium present within such mixing zones appear to result in enhanced toxicity for fish; rates of mortality are higher than in the original acidic waters.This project, therefore, will address the questions concerning the chemical/geochemical processes leading to enhanced toxicity towards fish in mixing zones between neutral or limed rivers and their acid tributaries. The chemical studies will include aluminium speciation, transformation processes and the kinetics involved. These investigations will be complemented by biological and physiological studies on possible toxic mechanisms responsible for the observed fish mortality.Experiments will be carried out in the field in two catchments in Norway and Scotland during different seasons (different hydrology, temperatures, and life stages of fish) and in laboratories under controlled exposure (Norway, UK, Belgium, and in the Netherlands). The experiments will focus on:- the characterisation of Al species by fractionation techniques, and trace element analysis;- transformation processes and kinetics involved, especially the polymerisation of 10w molecular weight Al-species;- interactions with other components influencing the polymerisation of Al species, in particular silicic acid, calcium fluoride and humic substances;- identification of biological responses, especially sublethal effects and fish mortality;- improvement of management practices for countermeasures taken in acidified water systems, e.g. liming of rivers and waters for agricultural practices. Campo scientifico social sciencessociologydemographymortalitynatural sciencesearth and related environmental scienceshydrologynatural scienceschemical sciencesinorganic chemistryalkaline earth metalsnatural scienceschemical sciencesinorganic chemistrypost-transition metalssocial scienceseconomics and businessbusiness and management Programma(i) FP3-ENV 1C - Specific research and technological development programme (EEC) in the field of the environment, 1990-1994 Argomento(i) 0106 - Biogeochemical cycles and ecosystem dynamics Invito a presentare proposte Data not available Meccanismo di finanziamento CSC - Cost-sharing contracts Coordinatore University of Keele Contributo UE Nessun dato Indirizzo ST5 5BG Keele - Staffordshire Regno Unito Mostra sulla mappa Costo totale Nessun dato Partecipanti (5) Classifica in ordine alfabetico Classifica per Contributo UE Espandi tutto Riduci tutto Agricultural University of Norway Norvegia Contributo UE Nessun dato Indirizzo 1432 Aas NLH Mostra sulla mappa Costo totale Nessun dato Katholieke Universiteit Nijmegen Paesi Bassi Contributo UE Nessun dato Indirizzo 1,Toernooiveld 6525 ED Nijmegen Mostra sulla mappa Costo totale Nessun dato NORWEGIAN INSTITUTE FOR WATER RESEARCH Norvegia Contributo UE Nessun dato Indirizzo 19,Brekkeveien 19 0411 Oslo Mostra sulla mappa Collegamenti Sito web Opens in new window Costo totale Nessun dato RISOE NATIONAL LABORATORY Danimarca Contributo UE Nessun dato Indirizzo Frederiksborgvej 399 ROSKILDE Mostra sulla mappa Costo totale Nessun dato Vlaamse Instelling voor Technologisch Onderzoek Belgio Contributo UE Nessun dato Indirizzo 200,Boeretang 2400 Mol Mostra sulla mappa Costo totale Nessun dato
