EU network of mesocosms facilities for research on marine and freshwater ecosystems open for global collaboration.

Artificial Stream and Pond System (FSA)

The Artificial Stream and Pond System (FSA) of the Federal Environment Agency (Umweltbundesamt, UBA) in Berlin ( will offer AQUACOSM Transnational Access (TA) for international scientists to participate in two different independent projects in 2018. The general experimental design is already established in both cases and external users are invited to contribute with additional parts to the respective topic. Since both projects will be conducted in the outdoor facility the precise start in spring 2018 will depend on weather conditions. A total of at least 200 person-days for 4-8 persons will be allocated to external users for AQUACOSM Transnational Access provision in 2018.

Project 1: Degradation of plastics at the freshwater shoreline – Development of detection methods, Project Lead: Stefan Meinecke, May to November 2018,

Offered TA person-days: up to 100

The degradation of macroplastics under natural conditions is mechanistically only poorly understood, especially because up to now there is no general established method for measuring degradation rates. We have prepared two stream mesocosms with a stony shoreline and constant wave exposure. The initial aim a three year lasting project is to find adequate methods and parameters to estimate degradation rate of various plastic materials. Beside optical or image-forming methods for the assessment of surface changes (i.e. standard light microscopes, a scattered light sensor and potentially a white light interferometer, which will be available on site), also material testing methods like tensile tests or comparative electron microscopy of surface structure might be promising for tracking plastic degradation. In addition chemical analyses could be considered in order to detect losses of additives or changes in the polymer structure as a proxy of the degradation rate. The latter approaches, especially chemical analyses, are not available on site and need to be an expertise by the guest scientist. Currently, the project aims on three different polymers (PET, PE, PBAT), but further types (e.g. material or shape) and hence also corresponding types of analyses are conceivably and will be supported by the host institute.

Project 2: Fate and degradation of a pharmaceutical in a freshwater stream mesocosm,

approximately from April to September 2018, Project lead: René Gergs

Offered TA person-days: up to 100

Metformin is one of the most commonly prescribed antidiabetic pharmaceuticals on the global scale and enters the waste water untransformed as there is no metabolism in human bodies. However, information on its fate in the water phase under natural conditions is scare and known degradation rates are ranging between few and more than 100 days. The project aims to investigate the transformation processes and ecotoxicological effects of Metformin under more natural conditions in two 100-m outdoor stream mesocosm containing a well-developed community including also macrophytes and benthic invertebrates. A special focus of the host institute is on degradation rates and the formation of transformation products under environmentally realistic conditions in the water phase, which will be measured on site. Furthermore, we are highly interested in including transformation processes in other compartments, especially sediment and macrophytes investigated by guest scientists. In addition, effects on bacterial communities or selected invertebrate species as well as bioaccumulation in various taxa would be valuable to add. The host institute can provide further support in terms of for example chemical analyses especially of nutrients, neutral tracers or similar by agreement.

Artificial Stream and Pond System (FSA)
Legal name of organisation
German Environment Agency
Organisation address

German Environment Agency

Primary contact information (PI)

Ralf Schmidt

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Years of Mesocosm Experiments
Since 2001
Description of Facility

Outdoor and indoor pond and stream system. The facility comprises 8 indoor and 8 outdoor ponds and streams, the latter of 1.6 km total length (indoor + outdoor). Water bodies are large enough to carry all trophic levels including fish

Controlled Parameters

Control of light, temperature, flow velocity, wind, colonization of insects etc.,

Simulation of groundwater flow in semi-natural conditions (influent/effluent flow regime, remobilization of substances)

Research Topics

Ecotoxicological, ecological, and hydrological studies (fate and effects of pesticides, biocides, pharmaceuticals, or industrial chemicals in ponds or streams; fate of viruses in bathing waters; model verifications; vertical mass transport water/sediment;
light pollution)

Facility location(s)
Primary interests

Ecotoxicological studies

Specialist areas

Upcoming years: mixture toxicity of chemicals, degradation of plastics, passive sampling (chemicals)

Source of Information
Photos of experiments/installations
Outside view of the hall housing the indoor artificial streams and ponds © Umweltbundesamt
Outdoor mesocosm system © Umweltbundesamt
Outdoor streams © Umweltbundesamt


Infrastructure (short name)
Artificial Stream and Pond System (FSA)
Installation (short name)

Berlin, Germany

Coordinates / (routes, areas if non-static)
Water / environmental conditions
Depths / bottom / surface

The Artificial Stream and Pond System (FSA) of the German Environment Agency (UBA) is a large and technically sophisticated experimental facility in Berlin (Figs 6.19.1-2). It comprises 8 outdoor and 8 indoor streams (100 m length, water volume of 40 m3 each), 8 outdoor and 8 indoor ponds (water volume of 60 m3 each) and associated equipment. In addition the facility comprises 18 small indoor ponds (water volume of 1 m3 each) and 8 small indoor stream channels (water volume of 2 m3 each).

Special features that make the facility unique in Europe are:

  •  Modular design (variable stream length, possibility to connect ponds and streams)

  •  Outdoor and indoor system

  •  Simulation of both flowing and stagnant waters

  •  Large size enabling tests on all trophic levels, including fish

  •  Availability of various water qualities, from ground to waste water

  •  Control of light conditions of the indoor mesocosms

  •  Adjustment of variable flow velocities between 0.02 and 0.5 m/s

  •  Option of riffle and pool sections in stream mesocosms

  •  Option of a terrestrial and littoral zone in the pond mesocosms, enabling the simulation of bank

    filtration including both downward and upward groundwater flow by means of drainage

  •  Option of pore-water sampling devices in the ponds

  •  Defined water circulation by means of artificial ventilation of the indoor ponds

Fig. 6.19.1. Outdoor flumes of UBA’s Artificial Stream and Pond System in Berlin, Germany. Photos: UBA

Fig. 6.19.2. Indoor experimental streams (left) and indoor ponds (right) with lighting systems. Photos: UBA

Instruments / sensors / equipment

Each stream and pond is equipped with online instruments to continuously measure conductivity, O2, pH, water level, temperature, turbidity and, in streams, flow velocity. Chemical variables such as contaminants in water, sediment and biota can be measured in the laboratory according to demands. FSA is well equipped with gas chromatographs-mass spectrometers (GC-MS), high-performance liquid chromatograph (HPLC), an inorganic carbon (IC) analyser, a TOC analyser, automated titration units, an ion chromatograph, a continuous flow analyser for nutrient analyses (N, P), etc. In addition, light conditions in and above the water of streams and ponds, chlorophyll a and phaeopigments, and many other biological variables are routinely analysed. All experimental data are fed into a central data base for quality checks and analysis. The input of data entry, in particular physico-chemical data, from defined analysis protocols is automated. The database user programme is independent of the system software and is available on the internet.

Modality of access

A total of at least 200 person-days for 4-8 persons, will be allocated to external users for AQUACOSM Transnational Access provision in year 2. Users supported by AQUACOSM are invited to contribute particularly to one of two projects: Fragmentation behaviour of plastics under hydraulic stress using saltwater and freshwater mesocsosms, and calibration of passive samplers for monitoring chemical contaminations in small streams.

Unit of access
What is available and when
What service and support facilities are available

Services currently offered by the infrastructure: The FSA is operated by permanent staff including 3 biologists, 2 engineers, 3 technicians, 1 electrician and 1 craftsman. The team oversees the scientific and technical planning and maintenance of the facility. Since its establishment in 2001, >30 projects have been completed, mainly on the fate and effects of chemicals on aquatic organisms under near-natural conditions (see

Special rules