New methods for assessing freshwaters in Germany

Abstract

European freshwater biomonitoring and assessment is undergoing a major shift. Current legislations, in particular the EU Water Framework Directive, demand for new approaches, which should be consistent throughout Europe. Many countries are now changing their monitoring schemes and consider organism groups, which have rarely been used in standard water management. New assessment methods are developed and implemented into water management in many countries. In Germany, the organism group most frequently used in routine biomonitoring are benthic invertebrates; however, the Saprobic System, even in the recently revised form, does not alone fulfil the requirements of the Water Framework Directive and needs to be supplemented by other approaches. Field and lab procedures have not been harmonised between the individual parts of Germany, and a combined evaluation of data from all of Germany has rarely been performed. Phytobenthos, macrophytes, and fish have not commonly been used in routine water management and no standard assessment methods have until recently been available. To fill these gaps, several projects at the interface of science and applied water management have been performed in the years 2000-2004. They have been funded by the Working Group of the Federal States on Water Problems (LAWA), the Federal Environment Agency (Umweltbundesamt), the German Ministry for Education and Research, and the European Union. The results of these projects have lead to advanced field-, laband assessment methods for all organism groups relevant for the implementation of the Water Framework Directive. These methods are now tested in practise and subsequently included into the monitoring systems of the Federal States. Furthermore, the projects have, for the first time, generated comparable data sources for a large number of rivers and lakes throughout Germany, which are of relevance beyond the development of assessment systems. Overall, applied limnological research in Central Europe has been greatly accelerated. This issue of the journal Limnologica aims to make key results of the research projects available to the international scientific community. Although many results of the research projects are mainly relevant for regional purposes, the new identification keys, field and lab protocols, typological results, and the general assessment approaches will be of relevance for scientists and water managers in all of Europe and beyond. Two papers of this special issue give a comprehensive overview of new phytobenthosand macrophyte-based classification methods, covering a-posteriori ecosystem typology, description of type-specific reference conditions, metric development for the main degradations, that can be detected with benthic plants like eutrophication, acidification and salinisation and the way forward towards an assessment system. These steps have been performed for both, rivers (SCHAUMBURG et al. 2004a) and lakes (SCHAUMBURG et al. 2004b). The focus of this issue is on rivers and benthic invertebrates. Here, the individual steps from basic taxonomic and methodological work to the development of an assessment system are described in separate papers. A new stonefly (Plecoptera) identification key is presented by