The experimental facility consists of 12 indoor mesocosms, so-called Planktotrons. The Planktotrons are custom-tailored units built of austenitic stainless steel, developed and established at the University of Oldenburg, Institute for Chemistry and Biology of the Marine Environment (ICBM) in Wilhelmshaven. Each tank has a fillable height of 1.2 m and an inner diameter of 0.8 m, resulting in a volume of 600 L. The 2-walled tanks with pillow-plate technology allow temperature control independently in three vertical strata by circulating heating or cooling medium between the two walls. Temperature is measured using PT100 sensors mounted on the rotating paddle at three different depths. Each temperature zone can be adjusted between 5 and 35 °C.

During the experiments, rotating paddles with regulated speed can be used to avoid wall growth and for mixing the water in the Planktotrons in regular intervals with defined speed. The paddle itself can easily be disconnected and modified or shortened for other experimental setups. Sampling can be conducted from the top or at six different depths by connecting a sampling lance to one of the sampling ports. Additional ports allow connecting Planktotrons among each other, which enables meta-community approaches or the usage of automated water-pumping on-line sensor instrumentation. Two fully controllable LED lighting units assure light conditions with a near-natural light spectrum.

Reference: Gall et al. (2017). Planktotrons: A novel indoor mesocosm facility for aquatic biodiversity and food web research. Limnology and Oceanography: Methods 15, 663-677. doi: 10.1002/lom3.10196

indoor (outdoor) – freshwater/marin – pelagic/benthic

• 12 indoor mesocosms with 600 l volume (height 120 cm, diameter 80 cm) for marine or freshwater experiments and natural or artificial communities
• 3 temperature zones: upper half, lower half, and bottom
• Build-in rotor prevents wall growth
• Six ports at different levels of the water column for direct sampling
• Planktotrons can be connected for metacommunity approaches
• Sediment inclusion possible

We conduct various projects with research foci on phytoplankton, ciliates, zooplankton, food webs, biodiversity, metacommunities and more. A summary of previous projects can be found here.