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(71-05) The use of survival, growth and feeding rates tests with Chironomus riparius larvae to assess water quality. Faria, Ana*,1, Nogueira, António1, Soares, Amadeu1, 1 Departamento de Biologia - Universidade de Aveiro - Campus de Santiago, 3810-193, Aveiro, portugal ABSTRACT- Ecological assessment of water quality is essential to the management of surface waters and the protection of aquatic ecosystems. Ecosystem functions depend on the availability and processing of energy. The major energy sources in running waters are detritus and aquatic plant biomass, whilst the major consumers of this energy are invertebrates. The incorporation of biomass from detritus material into animal biomass depends on its utilization by shredders and collectors. Chironomus riparius was used to study how water quality influences the survival, growth and the post-exposure feeding rates of a collector. Thus, in situ tests with C. riparius were used to compare contaminated and reference sites. Survival and growth tests were carried out, in each site, with 30 caged larvae exposed in situ during 6 days. Post-exposure feeding tests used 15 caged larvae, in each site, pre-exposed in situ for 2 days before the feeding trials. Growth was the most sensitive parameter whilst feeding rates were not significantly different between sites, mainly due to the high variability between within trials. Key words: field tests, Chironomus riparius, reference sites, contaminated sites |
