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

METU Mesocosm System

Legal name of organisation (short name)
Middle East Technical University (METU)
Organisation address

Orta Doğu Teknik Üniversitesi (ODTÜ), Middle East Technical University (METU), Üniversiteler Mahallesi, Dumlupınar Bulvarı No:1 06800 Çankaya Ankara/TURKEY, 06800

Infrastructure (short name)
METU Mesocosm System
Infrastructure address

METU Campus in Ankara, Turkey

Coordinates / (routes, areas if non-static)

39°53’17.39″ N 32°47’2.99″ E (DMS)

Facility location(s)
Description of the Infrastructure

Description of the infrastructure: The METU Mesocosm System is based at the METU campus in close proximity to the Limnology Laboratory (<1 km) and is a semi-mobile system that can be transferred to other locations by dismantling and mantling again. It consists of 16 cylindrical (1.2 m diameter) robust fibreglass tanks either 1.2 m or 2.2 m tall. In situ, the upper edges of all mesocosms are attached to pontoon bridges 20 cm above the water surface to avoid incursion of water during windy periods. Eight mesocosm tanks are arranged in two rows for ease of access. The pontoon bridges are wood constructions and the floating devices consist of 32 plastic barrels, each 120 L. The METU Mesocosm System is free floating and anchored only at the platform end, which, irrespective of wind direction, serves as a wave breaker and landing point for boats.

The METU Mesocosm System offers set-ups of low and high-water levels and the connection to sediment layers. Water levels differ between 1 and 2 m in the 1.2 and 2.2 m deep mesocosms, respectively. A 10 cm deep sediment layer can be added to each mesocosm, containing 90% (by volume) washed sand (grain size <1 mm) and 10% sediment from a lake for assembling the sediment mixture for the mesocosms. To simulate shallow, fully mixed lakes, the water in the mesocosms is continuously circulated during experiments using electrically powered pumps. To standardise initial conditions and enable the potential for developing a diverse flora and fauna, the mesocosms can be inoculated with a mixed sample of sediment, plankton, aquatic plants and fish.

The Limnology Laboratory operating the METU Mesocosm System is equipped with sampling gear, analytical instruments (e.g. auto-analyser for N, and other nutrient analyses, microscopes, HPLC, flow-cytometer, sampling gear for water, fish and macrophyte sampling) and a walk-in climate room., METU has a central laboratory facility equipped with elemental analyser (particulate C and N analyses), ICP-MS (trace elements analyses), Fourier transform infrared spectrometer (FTIR), as well as modern molecular-biology laboratories.

Size and dimensions of METU Mesocosms System mesocosm (left) and young researchers at work.
Primary contact information (PI)

Meryem Beklioğlu

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Years of Mesocosm Experiments
2011, 2012, 2018 - present
Description of Facility
Controlled Parameters

water depth and nutrients (both TP and TN)

Research Topics

Role of water level on ecosystem processes (e.g. C and  N) as well as impact of food additives (TiO2) on food web structure and ecosystem processes

Primary interests

Role of hydrological alteration on ecosystem structure and function of shallow lakes

Specialist areas
Source of Information
Photos of experiments/installations
Infrastructure (short name)
METU Mesocosm System
Modality of access

Modality of access under AQUACOSM: A total of at least 630 person-days will be allocated to external users during years 2-4 of the AQUACOSM Transnational Access provision. A minimum access for 9 persons is envisaged for 20 days each year. External users will be prioritised for using the mesocosms throughout the AQUACOSM TA activities. To maximise scientific output, efforts will be made to integrate the AQUACOSM TA activities into other projects at the facility. Access to the facility by international scientists has already been rewarded by a publication in a leading ecotoxicological journal.

Modality of access under AQUACOSM-plus: A minimum of 500 person-days will be allocated to external users through TA provided under AQUACOSM-plus. It is anticipated that AQUACOSM-plus will support stays of at least 4-5 persons for 65 days per year in M10-21 and M34-45. To maximise the scientific outcome, efforts will be made to integrate the TA activity with other on-going and planned projects at the facility. International collaboration at METU has already produced a high impact factor publication in addition to publication of the REFRESH project. In 2018, an in- situ mesocosm experiment investigating the impact of microplastics on the littoral food web was carried out with 10 students and scientists supported through TA during AQUACOSM. For summer 2019, METU Mesosystem System are participating in the AQUACOSM-JOMEX experiment with 13 TA participants from Europe and Brazil.

Unit of access
What service and support facilities are available

Services currently offered by the infrastructure: The METU Limnology Laboratory offers scientific experience and instruments needed for analyses of nutrients, identification of phytoplankton, zooplankton, macrophytes (see above). Users also get access to METU’s fully equipped central laboratory facility. METU Mesocosm System set-up provide natural opportunities to work on lake water level changes, and consequently water volume changes and salinisation induced through evaporative water loss in two different water depths, for a better understanding of climate change. Each set of low and water level mesocosms (12 each set) can be used separately for different purposes. The set-up allows investigating the effects of drought in relation with eutrophication or toxic chemicals on salinisation, water level change, trophic structure, dynamics, nutrient/toxic chemical balances, organisms from bacteria to fish, metabolism, adaptation and microevolution.

Support offered under AQUACOSM: Users will be given access to the mesocosm facility as well as the full range of laboratories and instrumentation available at the METU Mesocosm System and METU Limnology Lab. This includes physical, logistic, technical and scientific support. AQUACOSM scientific staff and the task leader will further assist users with supervising and training as well as providing assistance throughout the stay.

Support offered under AQUACOSM-plus: All visitors will have access to the full range of laboratories and instrumentation available at the METU Mesocosm System and METU Limnology Lab, physical, logistic, technical and scientific support will be provided. The AQUACOSM-plus Post-Docs and PhDs, and the project leader will further assist the users with running scientific supervision, training and technical assistance throughout the stay.

Special rules