METU Mesocosm System II is design to allow researchers to study shallow lake and pond ecosystems ecological structure, functions and diversity under the effects of global grand challenges. Especially MMS II is suitable for studying the effects of salinization on lakes as it is located in in arid Steppe climate where salinization is a major problem.

METU, Mesocosm System II includes 24 mesocosms, with 2m wide and 1.65m in height. They are buried into the ground up to 1m depth and each have 30 cm of sediment (1:1 ratio of washed sand and natural sediment form different lakes). To mimic the presence of wind induced current and prevent thermal stratification, water in each mesocosms is mixed via a pump.

Mesocosm System II includes 24 mesocosms, with 2m wide and 1.65m in height. They are buried into the ground up to 1m depth with 30 cm of sediment (1:1 ratio of washed sand and natural sediments from different lakes). To mimic the presence of wind induced current and prevent thermal stratification, water in each mesocosms is mixed via a submersible pump. The mesocosm are fed groundwater.

The system is still under development and we are aiming at equipping some (if not all) of the mesocosms with 1) a programmable, remote controlled electrical heating system, with heating is adjusted in reference to the ambient temperature tanks, sensors for temperature conductivity and dissolved oxygen allowing HF measurements, 3) flow-through-condition with adjustable hydraulic retention time. The mesocosm are arranged in the following configuration and also see the picture.

A similar system is established at the Marine Institute in Mersin at the south coast of Turkey.

We are able to measure physicochemical parameters, including water temperature, salinity, electrical conductivity, oxygen, pH, water transparency, alkalinity, suspended solids, color, nutrients (NO3, NO2, NH4, total nitrogen, PO4, and total phosphorus), major ions, and dissolved organic carbon, besides biological communities, such as bacterioplankton, phytoplankton, zooplankton, ciliates, heterotrophic nanoflagellates, periphyton, chlorophyll-a, major photosynthetic pigments, macrophyte cover, fish, and macroinvertebrates as well as metabolism, greenhouse gas emissions (CO2 and CH4), and decomposition.