Leibniz Association
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Address:
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Germany
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Access to research platform and laboratory facilities.
Mesocosm facility - The research platform was set up in a natural clear-water lake for experiments conducted over a period of at least 20 years. It consists of 24 mesocosms, each 9 m in diameter and 20 m deep, which separate water volumes of about 1250 m3 from the lake. The enclosure walls, which extend into the lake sediment, are made of a special tarpaulin that is fixed to a floating aluminium ring. By opening zippers water can be occasionally exchanged between the mesocosms and the lake in a controlled manner. Submersible pumps, a tubing system, and perforated water distribution rings that can be lowered to any depth facilitate experimental changes of mixing regimes to simulate physical conditions expected in response to climate change. Sediment traps collect sinking particles and floating flux chambers capture gas emissions to the atmosphere. Automatic profilers continuously record depth profiles of eight physico-chemical standard parameters: light intensity, temperature, electrical conductivity, pH, oxygen, redox potential, turbidity and pressure. In addition, a fluorescent probe can distinguish up to four algal groups. The profilers are controlled by industrial computers that also store the recorded data and transfer them to a central data base for further processing.