The FLOW project: Analysing streams - creating knowledge together

 

Motivation

Over 90 % of officially monitored rivers in Germany are in a poor ecological status (Federal Environment Agency, 2022). At the same time, there is a lack of reliable data on the status and pollution exposure of small streams, i.e. streams with catchment areas of less than 10km2, as these are not included in the monitoring of the European Water Framework Directive (EC-WFD, 2000).

Many people enjoy spending time near rivers and streams, but often know little about freshwater ecosystems and the human activities that negatively affect them. Others are very interested in the ecological status of watercourses and already regularly observe the streams in their neighbourhood.

The FLOW citizen science project aims to co-create new knowledge about stream health! We provide training and opportunities for exchange between interested community members and different stakeholders on the topic of freshwater monitoring and protection.

 

Project goals

• Scientific objectives

  • Collect standardised, spatio-temporally comprehensive data on the ecological status of small streams across Germany to assess the status and development trends of stream health and complement official freshwater monitoring
  • Develop a user-friendly citizen science data management system (web application)

• Educational and participation-related goals

  • in cooperation with educational institutions and environmental and angling associations: strengthen social awareness of the importance, condition and protection of rivers and streams
  • promote knowledge and skills for stream monitoring through appealing learning materials, practical training and exchange of experience between participants, scientists and experts

• Freshwater protection goals (future perspective)

  • Collaboration with local and federal environmental agencies and water authorities and the Federal Environment Agency (Umweltbundesamt) to use citizen science data for regulatory studies and reporting
  • joint planning and implementation of local, low-threshold measures for stream restoration together with local citizen science groups, associations, authorities and land managers

 

Methods

• Assessment of stream ecological status in accordance with the EU Water Framework Directive

  • Assessment of stream hydromorphology according to the German Working Group on Water Issues (LAWA, 2019). All six main parameters of hydromorphology according to LAWA are recorded (i.e. watercourse, longitudinal profile, cross profile, bed structure, bank structure, water body environment) including all sub-parameters. The stream type of the sample sites is determined to calculate hydromorphology index values.
  • Point measurements of chemical-physical parameters (e.g. ammonium, nitrite, nitrate, phosphate, water temperature, oxygen content, pH value, ion conductivity) using colorimetric test kits and measuring devices.
  • Standardised multi-habitat sampling of macrozoobenthos. For this purpose, all substrates in the stream bed are first mapped in a 100m sample section, then a total of 20 kick samples are taken with a landing net (distributed proportionally to the substrates present). Invertebrates are then sorted out of the organic material and identified alive on site down to the family level.
  • Analysis of pesticide exposure at the stream sample sites using the SPEAR bioindicator (SPEciesAtRisk, see www.ufz.de/index.php). SPEARpesticides is a bioindicator that classifies macroinvertebrates on the basis of certain ecological traits and thus determines the proportion of pesticide-sensitive species at each sample site. The resulting species composition provides an indication of the extent of pesticide contamination of the sample sites.

• Criteria for sample site selection

  • Size of the catchment area upstream of the sample site max. 30km2, reference: average width of the stream 0.5 to 2m
  • Surrounding area of the sample site: near-natural (forest, meadow) or agricultural land use (arable land, pastures)
  • clearly recognisable flow velocity (at least 0.1 m/sec), please DON’T select stagnant waters (ponds, lakes) or streams that frequently dry up!
  • Stream bed allows for the presence of benthic invertebrates ‘macrozoobenthos’, if necessary, test by netting (sample site with completely concreted stream bed is unsuitable!)
  • no sewage treatment plants or other point sources upstream of the sample site
  • streams in urban areas can be sampled, but may not be included in our studies, as we are mainly investigating the ecological status of streams in near-natural and agricultural areas.

• Project procedure

  • January-March: Online and onsite training course for citizen science group leaders, provision of free learning and field materials. Based on this, preparation of the volunteer groups on site by the trained group leaders.
  • April - early July: Annual nationwide FLOW field season for stream assessment. Local stream monitoring events are organised by participating citizen science groups (with support from the FLOW team).
  • October/November: Annual project conference to present and discuss the monitoring results.

 

Cooperation with MERLIN

The MERLIN project is an EU-funded joint project for the ecological restoration of freshwater ecosystems led by the University of Duisburg-Essen.
The aim of MERLIN is to identify and implement innovative and effective solutions for restoring the ecosystem functions of aquatic ecosystems, to promote biodiversity protection, flood retention and carbon sequestration by aquatic ecosystems.

Citizen science projects such as FLOW have great potential to support the monitoring of freshwater health and can also help to plan and implement evidence-based restoration measures.
In our current feasibility study, we are therefore investigating how existing citizen science approaches can be used and adapted to monitor freshwater restoration measures. We are developing a practical guide for planning and implementing low-threshold stream restoration measures that can be initiated by citizen science and community groups. Depending on the stream type, the ecological condition of the watercourse, the surrounding land use and the identified stressors, the following measures may be appropriate to improve stream status: planting site-specific trees and shrubs in riparian areas to provide shade and improve habitat structure, or introducing gravel or driftwood collectors to improve substrate and flow diversity.
Successful cooperation between local citizen science groups, associations, authorities and landowners is essential for the professional planning and implementation of such measures. The implementation process also requires time and expertise to select suitable sites and measures that are accepted by all stakeholders. The implemented measures can then be further optimised and adapted to the local conditions based on the local monitoring results.

The introduction of gravel (photos on the left) increases substrate diversity, reduces erosion of the stream bed and leads to a dynamic restructuring of the transverse and longitudinal profile of the stream. Driftwood collectors (photos on the right) promote the retention of organic material and support the restoration of natural bank and bed structures. Photos: Roland Bischof.

Action campaign #ourRivers 2024

From May to the end of September 2024, we are running the nationwide action campaign #unsereFlüsse (#our rivers) as a team from the Helmholtz Centre for Environmental Research UFZ Leipzig and media professional from the German public television (ARD).
The aim of the campaign is to motivate as many people as possible to observe and report the habitat quality of their streams with a low-threshold participatory offer. We have developed a short online questionnaire for this purpose. This is a greatly simplified version of the FLOW protocol for water structure assessment.
Various environmental associations, the Federal Environment Agency (Umweltbundesamt), the Federal Agency for Nature Conservation (Bundesamt für Naturschutz), the German Angling Association (DAFV), the Scouts, Omas for Future and many other organisations are supporting our call for participation. Currently (mid-August 2024), we have already received over 2,300 stream records from all over Germany.

Link of FLOW project and action campaign

This year's action campaign is an introductory programme for environmental education in the field of freshwater ecology for anyone who wants to take part spontaneously. The aim of the campaign is to increase public awareness of our streams and hopefully gain political support for further funding of the FLOW project. In this way, we can draw attention to the FLOW project, with which we collect scientifically standardised data. We also hope to attract more volunteers who may wish to take part in the FLOW project next year.
The FLOW project is our long-term citizen science project, which analyses the ecological status of streams in a comprehensive and standardised way. The results of your FLOW monitoring events will be incorporated into scientific studies. We are currently actively seeking to promote and consolidate the FLOW network in the long term, including through the action campaign, to create new knowledge on freshwater health together!
The results of the action campaign will be presented in various press reports in autumn 2024 and in an ARD documentary in October 2024.

 

 

Background

• Current status and pressures on small streams

  Small streams make up about 65 percent of Germany’s watercourse network. Due to their diverse structures, small streams provide a habitat for countless animal and plant species. As ecological hotspots, they fulfil important ecosystem functions: They preserve biodiversity, decompose organic material, purify water and retain it in the landscape, and provide areas for local recreation. At the same time, small streams are subject to a wide range of pressures. Interventions in natural hydromorphology, substance inputs from agricultural and urban sources and climate change are major stressors that in many cases deteriorate the morphological, physico-chemical and biological status of streams.
  The European Water Framework Directive (EC-WFD 2000) was adopted in 2000 to protect surface waters and reduce freshwater pollution. It requires EU Member States to achieve good chemical and ecological status for all their surface waters by 2027 at the latest. A comprehensive monitoring network has been set up for this purpose. However, 60% of European rivers and 90% of German rivers remain in poor ecological condition. Moreover, small watercourses with a catchment area of less than ten square kilometres are not covered. In the WFD monitoring and reporting.
  To fill this knowledge gap, over one hundred streams throughout Germany were analysed in 2018 and 2019 as part of the National Stream Monitoring (KgM). This intensive monitoring programme measured pesticide and nutrient concentrations, assessed stream hydromorphology, recorded physico-chemical parameters and examinded the invertebrate community (macrozoobenthos).
  The results showed that pesticide inputs are the most important stressors for vulnerable macrozoobenthos communities in small, agricultural streams. In spite of existing regulations, pesticides exceeded the so-called ‘regulatory acceptable concentrations’ (RAC) at more than 80 percent of the monitoring sites. And even at lower concentrations, a decrease in the diversity and number of vulnerable species could already be observed.
  The evaluation of the 2021-2023 FLOW monitoring confirmed these results. Click here for the original study in English and here for a summary of the results in German.

  Photo Bach Brigitte Osterath

• Influence of pesticide inputs on macrozoobenthos communities

  Numerous laboratory and field studies have shown that pesticide inputs into watercourses have a negative impact on aquatic organisms. Around 40 percent of the analysed aquatic invertebrate species are vulnerable to pesticides. These species are characterised by a high sensitivity and probability of exposure as well as a low ability to migrate and a low reproductive potential.
  With increased pesticide concentrations, these sensitive species, such as certain caddisfly, mayfly, stonefly and dragonfly families, disappear and the occurrence of insensitive species such as worms and aquatic snails increases.
  These changes in the benthic invertebrate community can be recorded using the SPEARpesticides bioindicator. The indicator was developed by Prof. Matthias Liess at the UFZ and describes the proportion of species sensitive to pesticides at the analysed stream sample site. The higher this proportion, and thus the SPEAR value, the lower the pesticide contamination. The SPEARpesticides indicator can therefore be used to draw conclusions about the pollution of streams by pesticides based on the composition of the macrozoobenthos communities.

  Caddisfly larva (Limnephilidae).
  Photo: Julia von Gönner

  
  Damselfly larva.
  Photo: Rainer Dückerhoff