Algen gehören in Flüssen zu den größten Primärproduzenten; dabei wird seit 1991 beim 1. Symposium in Düsseldorf ihre Eignung für Monitoringzwecke überprüft. Als Ergebnis soll eine gut anwendbare Methode (Bestimmung der Wasserqualität mit Algen) entwickelt werden, die mit den Vorgaben der EG-WRRL konform geht. Dabei spielen das Phytoplankton und die Diatomeen eine wichtige Rolle.

Da Algen auch für die Fischerei von großem Interesse sind, ist dieser Band besonders geeignet, die neuesten wissenschaftlichen Ergebnisse der "Algenforschung" kennenzulernen.

Dr. Hartmut Poschwitz

www.vdff-fischerei.de/html/buchbesprechung.html

Zum Spektrum der im Vollzug der Wasserrahmenrichtlinie zu erfassenden Gewässerorganismen gehören auch die Plankton- und Benthosalgen. Dies hat die Suche nach Indikatoren und die Formulierung von Indices auch bei den Algologen angeregt. Von den zahlreichen, bisher vorgeschlagenen Bewertungsverfahren, entwickelt an verschiedenen systematischen Gruppen bzw. Lebensformen, hat keines allgemeine Anerkennung und überregionale Verbindlichkeit erreicht. Es bleibt bei vielen Einzelbausteinen, die durch das Symposium vermehrt werden und die der mit Gewässerbewertung Befasste zur Kenntnis nehmen muss; bei den vorliegenden Beiträgen verdient das breite Länderspektrum besonderes Interesse. Jenseits aller Bemühungen um die methodische Vorherrschaft wird deutlich, dass auch das beste Auswerteverfahren Defizite in der Qualität der biologischen Daten und fehlende autökologische Kenntnis nicht ausgleichen kann.

Lauterbornia 62, p. 26

The activities around the subject “Use of algae for monitoring rivers” are based on an informal international group (address list plus a variable steering committee) originating back to 1991 when the first European workshop took place in Düsseldorf (Germany). Contributions from the first three workshops have been published by the local organizers (and are partly still available), whereas from the 4th and 5th meeting no specific volumes appeared, but of a few contributions published in periodicals (e.g. Journal of Applied Phycology). Whereas in the early stages the group especially encouraged the development of multiple new methods for using algae in river quality monitoring (all algal group approach, passive monitoring, bioassays, etc.) the organizers of the present meeting’s volume pinpointed that the main objective of the meeting was to focus on the development of one harmonized method as a service for the implementation of the European Water Framework Directive (EWFD). Although European Standards (guidelines) have been developed within the context of earlier meetings (in appendix sessions) the focussing in one single topic (benthic diatoms and ecological quality) seems questionable and may hinder future development.

As shown by the contents of the contributions there is in fact a focus set on benthic diatoms, the fore-runner of all actual methods for ecological river quality analysis. Nine out of the 16 papers are based on benthic diatoms. By the direct involvement of the host country in large river studies, however, the second focus related to the EWFD concerned river plankton studies. In these studies the phytoplankton assessments are mainly based on all taxonomic groups and experiences from lake studies, not exclusively on diatoms (five contributions). One river study used desmids for slow flowing rivers (Feher). The application of the one method in focus (benthic diatom data and OMNIDIA software) can lead to a non-critical use and multiple numerical regressions analyses between different indices (Solak et al.) without a parallel analysis of environmental data. In another case, however, a progressively critical and reflected testing of diatom indexing methods was applied to identify the most important (key factor) river management issues (Vilbaste et al.). Within the newly established national diatom methods (Hlubrikova et al., van Dam et al.) bioregional aspects across borders have been neglected until now. Diatom studies also concern the definition of the cleanest reference conditions from remote sites (Picinska-Faltynowicz) and the intercalibration of diatom data with other biotic indices (benthic invertebrates) in a river basin in Spain (Blanco et al.), although in this study it seems unlikely that the higher number of statistical evaluations should really result in the best information. In one single case the passive monitoring of heavy metals by macroalgae was tested (Komulaynen & Morozov).

The new approaches concern the application of SOM (self-organizing maps) as useful statistical method for biological / species-related ecological data (Varbiro et al. 1 and 2) and molecular fingerprinting to supplement/ facilitate taxonomic work (Szabo et al.).

The overall volume is well-edited and shows almost no major printing/ typing errors. All the contributions have optically clearly structured figures and tables and well edited reference lists. However we encountered one incorrect wording, i.e. “eutrophilous”, for which it is hard to find the correct expression (eutraphentic?).

In conclusion the volume shows clearly that a significant progress has been reached within the last three years initiated in the context of the EWFD. An increasing number of countries are applying successfully algal methods for ecological quality monitoring and river protection. It seems even as if this European enthusiasm would have an impact to adopt algal methods in other countries (e.g. Iran, Turkey). However there is a danger in all these efforts since we seem to forget the roots. One step back and more discussion with expert scientists and the input of experiences from abroad (e.g. South Africa, USA) would help to find the right line between over-standardization of a single key method and software and the necessary experimental testing of particular issues (i.e. tests of species responses to environmental constraints, bioassays, culture-based studies). Most of the actual indexing systems are merely based on diatoms and statistical evaluations of environmental data, what has led to “apparent” analyses of species tolerances and preferences. It seems as if in future we would need both species-specific testing and testing of ecoregional aspects versus site-specific and river-type-specific aspects independently from national borders and in relation to other biota. We hope to encourage future organizers to tackle those and other key problems rather than to drop out essential international input as becomes evident from the contributions to this volume. Why not to initiate new ideas, i.e. the development of electronic probes for key taxa identification or a European iconographic database?

E . ROTT, Innsbruck

Nova Hedwigia 87/1-2