Orta Doğu Teknik Üniversitesi (ODTÜ), Middle East Technical University (METU), Üniversiteler Mahallesi, Dumlupınar Bulvarı No:1 06800 Çankaya Ankara/TURKEY, 06800
METU Campus in Ankara, Turkey
39°53’17.39″ N 32°47’2.99″ E (DMS)
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.
water depth and nutrients (both TP and TN)
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
Role of hydrological alteration on ecosystem structure and function of shallow lakes