From the results, the researchers have derived recommendations for the design of the monitoring programmes and surface water manageme
Identification of causes by determination of species
Investigations and evaluation of macroinvertebrates in Swiss running waters have been carried out according to the Swiss modular concept for stream assessment since 2010. It requires the recording of the organisms on the family level. The model analysis generally confirms the assessment method: families classified as sensitive respond more strongly in the model to anthropogenic stressors. At the same time, the study shows that a finer taxonomic resolution, namely the identification of species, would provide additional valuable information. This would allow a better identification of the specific causes that could influence water or water-body quality.
More data, increased validity
The greater the volume of data available for analysis, the higher the statistical power. For future analyses it is therefore essential that as many monitoring programs as possible submit their macroinvertebrate data as well as additional information like substrate data to the MIDAT database.
Unified monitoring concepts
Today, Cantons identify different groups of macroinvertebrates down to the species level. For a Swiss-wide evaluation, it would make sense to always identify the same groups in this detailed taxonomic resolution. A unified list of taxa for species identification would therefore be an advantage. The Eawag study can contribute to judging for which groups this would be especially valuable.
Extended monitoring design
To better disentangle major influence factors on freshwater communities, it is worthwhile to include additional locations to the monitoring programme. Locations with rare combinations of influence factors are especially valuable for the analysis, such as sites with low water temperature and impaired water quality.
Integral management of surface waters
Plants and animals living in surface water ecosystems are typically sensitive to multiple stressors, for example poor water quality, monotonous high flow velocity, and increased water temperatures. In considering measures to improve the ecological status of surface waters, a combination of measures should be recommended, as far as possible and necessary. For example a restoration combined with upgrading of water treatment plants and reduction of harmful agricultural inputs upstream.
Schuwirth and Caradima have published a more detailed summary of the results in today’s issue of the journal Aqua & Gas, in cooperation with the Federal Office for the Environment FOEN and the Atelier für Naturschutz und Umweltfragen AG UNA: “Analyse schweizweiter Makrozoobenthosdaten: Erkenntnisse über anthropogene Einflüsse und Monitoring Design”.