Mesocosm infrastructure at Åbo Akademi University

Archipelago Mesocosm Network – A community-scale experimental system at Åbo Akademi University

Past and ongoing experimental manipulations



At Åbo Akademi University, across the Archipelago Sea and Åland Islands, we maintain a research infrastructure network for community-scale experimental research.

Manipulating community composition, as well as diverse underwater climates, including their extremes (such as marine heatwaves), allows us to glimpse into the future ocean.

Mesocosms represent a tool to bridge laboratory (Petri-dishes to aquaria) and field experiments (1) and provide the advantage that any underwater climates can be manipulated synchronously (common garden) and replicated.

Two mesocosm systems, of 20 600 L tanks each, are located at the Skärgårdscentrum in Korpoström (Archipelago Sea) and at Husö Biological Station (Åland Islands)

The systems mimic most natural conditions in nutrients and organic matter and daily fluctuation of abiotic factors such as water temperature, salinity, pH, and oxygen, as well as light.


Setup information

Each system comprises 20 600 L polyethylene tanks (Schwer-PALOXE 1130 x 930 x 600 mm) supplied with a constant flow-through of unfiltered seawater from a water depths of 2 m (Korpoström: GRUNDFOS SP 5A-12 R 5 from around 20 m from the tank system; Husö: Isku-Jet 3RP from around 300 m from the tank system).

Experiments can be run flexibly, in full 600 L tanks or in experimental (semi-independent), for example 20 L, subunits (vinyl buckets PP Plastex®).

Constant and equal inflow of water is achieved by custom-made INFLOW units (with adjustable flow rates) or HEADER tanks (10 L buckets PP OrthexTM above the water level distribute water passively among the experimental units via 90 cm long silicon tubes – 4 mm diameter, Versilic Silicon Tubing #760320).

Natural light conditions are maintained through shading nets at ~440 µmol photon m-2 s-1 (Li-Cor model Li-1400 data logger), representative of 3 m water depth in the area during summer.


Technical information

Each mesocosm is equipped with three to eight internal titanium heating elements (600 W, Schego)

Cooling is achieved by commercially available electrical titanium heat exchangers (Titan 2200, Aqua Medic)

Heating and cooling elements are automatically regulated by the aquarium controllers with a hysteresis of 0.1-0.2 °C (GHL ProfiLux 4(e); Aqua Medic T controller twin (PRO))

Circulation pumps (EHEIM 56.7 L/m  / Tunze TURBELE STREAM 6085) provide water currents and equally, distribute heat inside the mesocosms

Temperature, salinity, pH, O2, and light are monitored by HOBO loggers (HOBO Pendant Light/Temperature Data Logger, Onset Computer Corporation), as well as with portable reference systems (hand-held probe MULTI 3630 IDS, with sensors: SenTix 940, FDO 925, TetraCon925, WTW Germany; Li-Cor model Li-1400 data logger). Chl a is measured using an Aquafluor Handheld Fluorometer. Samples for porewater and water-column nutrients are taken through syringes, including Rhizon Samplers (Rhizosphere Research Products).


Please come and work with us !!!

Contact:   Dr. Christian Pansch-Hattich
Prof. of Marine Ecology

Åbo Akademi University
Henrikinkatu 2
20500 Åbo/Turku

Mobile: +358 50 5126850




(1) Gerhard M, Koussoroplis A-M, Raatz M, Pansch C, Fey SB, Vajedsamiei J, Calderó-Pascual M, Cunillera-Montcusí D, Juvigny-Khenafou NPD, Polazzo F, Thomas PK, Symons CC, Beklioğlu M, Berger SA, Chefaoui RM, Ali Ger K, Langenheder S, Nejstgaard JC, Ptacnik R, Striebel M (2022) Environmental variability in aquatic ecosystems: avenues for future multifactorial experiments. Limnology and Oceanography – Letters 8:247-266 (