PARENT SESSION

2M - Monitoring of function and structure
Poster Hall
8:30 AM - Wednesday, 30 April 2003
Chair: Schulz, R.¹, ¹

(WEP/148) TARGET; use of field bioassays to assess the impacts of stress on ecosystem function of European rivers.

Conrad, Anne ¹, Baird, Donald¹, Loraine, Maltby², Nogueira, Antonio³, Jak, Robbert⁴, Soares, Amadeu³, ¹ Environment Group, University of Stirling, Stirling, UK² Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK³ Dept. Biologia da Universidade de Aveiro, Aveiro, Portugal⁴ Dept. for Ecological Risk Studies, TNO-MEP, Den Helder, The Netherlands

ABSTRACT- In the EC Water Framework Directive, ecological assessment of water quality is fundamental to the management of surface waters and the protection of aquatic ecosystems. The EC 5th Framework TARGET project with partners in the UK, the Netherlands and Portugal provides a complementary approach to conventional measures of ecological quality within river ecosystems using simple tools to assess ecosystem function. TARGET tools aim to establish ecological standards for river water quality. The tools employ measures of resource processing rates (primary production, herbivory, detritivory) in the form of in situ bioassays with locally-sourced organisms. Results are being incorporated into a novel on-line database, which will ultimately be accessible from the project web site (www.target-eu.org). TARGET project outputs support the objectives of the EC Water Framework Directive by providing direct assessment techniques for 'functional sustainability', which can be used to complement existing techniques applying structural ecological measures. The primary producer-grazer bioassays aim to gauge system performance in terms of supply and demand. The supply side bioassay is based on a technique which immoblises algae in alginate beads. Demand-side performance is measured using invertebrate grazers (e.g. Daphnia, Lymnaea spp.). Similarly, in situ bioassays are used to assess detritus-detritivory processes. Shredder organisms (e.g. Gammarus and caddisfly) are used to measure detritivory and leaf packs give information on detritus breakdown rates in the system. The suite of in-situ bioassays has been deployed in river sites of varying ecological quality across three different European ecoregions. Results obtained in the UK will be discussed and used as an example to demonstrate the use of these data in ecological water quality assessment.

Key words: functional assessment, river, bioassays, ecological quality indicators