Report on Harmonisation of freshwater biological methods

108. Process Assessment focuses on evaluation of taxon characteristics such asfunctional groups and species traits. The Lotic-invertebrate Index for Flow Evaluation(LIFE) assesses the impact of variable flows due to regulation or augmentation onbenthic populations. Every regularly encountered invertebrate species and family ofBritain has been assigned to one of six groups which are related to certain flowconditions.109. The definition of distinct reference communities as basis of assessment forlarge watercourses is difficult due to substantial anthropogenic influence and theoccurrence of newcomer species occupying ecological niches. Here, the concept ofProcess Assessment is suitable as it appraises the performance of ecological functionsrather than the presence of individual species. The Potamon-Characterisation-Index(PTI) thus operates on the basis of an “open“ taxon list in which all species showingpreference to potamal habitats are indicators of high quality. By definition newcomershave low ecological values.110. Rapid Bioassessment represents a combination of biological and habitatquality assessment emphasising a low-cost approach through reduced sampling andefficient data analysis. Investigation of both biotic and habitat features aims atobtaining an integrated ecological watercourse assessment. In Europe the only RapidBioassessment Protocol in current usage is the Spanish ECOSTRIMED method, whichcomprises the Spanish modification of the BMWP score.111. A fundamental concept of Multimetric Assessment is to analyse communityhealth composed of community structure, community balance and functional feedinggroups (Barbour et al., 1992). In this context it represents an integrative approach towater quality assessment combining various metrics like Biotic, Saprobic andDiversity Indices, and Process Assessment measures.112. Within the European research project AQEM (“The Development and Testingof an Integrated Assessment System for the Ecological Quality of Streams and Riversthroughout Europe using Benthic Macroinvertebrates”) multimetric assessmentsystems using benthic invertebrates have been developed for a limited number ofstream types in Austria, Czech Republic, Germany, Greece, Italy, Netherlands,Portugal and Sweden (AQEM Consortium, 2002). Based on this experience, Germany(Meier et al., in print) and Austria are implementing multimetric assessment at a92