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KOB (Kiel-Outdoor-Benthocosms)

GEOMAR-Helmholtz Center for Ocean Research
Infrastructure Description

The GEOMAR Kiel-Outdoor-Benthocosms (KOB) designed to simulate future underwater conditions expected under climate change has been successfully used since 2012. The facility consists of 6 experimental units holding 3000 L each, which can be sub-divided into 12 autonomous units of 1400 l. Covers translucent to all solar wave lengths can be used if headspace conditions need to be controlled. Water movement and turbulence is controlled by water through-flow, internal circulation and wave generators to produce a wide range of hydrodynamic conditions. Natural upwelling events are simulated with a deep-water hose supplying water from below the thermocline. Possible simulations include abrupt changes in salinity, O2, pH, pCO2 and nutrients. The entire infrastructure, including a container with master computers, freezers and workshop, is installed on a floating platform.

A unique feature of KOB is that it can track the short-term fluctuations characterising natural regimes of environmental factors, such as temperature, pCO2, O2 and nutrient concentrations. It is operated in flow-through mode to create in- situ conditions in real-time by adjusting the climate-change factors of interest to dynamic target values based on the experimentally desired deviation from a continuously recorded baseline in the field. Adjustments to the target values are fully automated by means of a sophisticated instrumentation and control (I&C) system that also records a range of environmental variables continuously. Novel software serves to mimic the exact regimes of temperature, pH, O2 and other environmental factors of a given year in the past or any deviations from those conditions.


Kiel Outdoor Benthocosm (KOB) facility at Kiel bight, Germany. Photos: GEOMAR

Facility Description

off-shore/outdoor/indoor – pelagic/benthic – marine/brackish

Kiel Outdoor Benthocosms – KOB

outdoor – benthic – marine/brackish

Floating infrastructure consisting of sub-dividable 3500 liter tanks, optionally covered by a fully translucent hood. When the system works in a flow-through mode all in situ fluctuations are admitted to the tanks and experimental treatments represent controlled deviations (delta-treatments) from this naturally fluctuating baseline

Organisation Address

GEOMAR-Helmholtz Center for Ocean Research, West shore campus

Düsternbrooker Weg 20




GEOMAR-Helmholtz Center for Ocean Research, East shore campus

Wischhofstr. 1-3




Infrastructure Address



Information Sources


Media report: Window on future ocean


KOB – Kiel Outdoor Benthocosms (Photo: Mark Lenz)KOB – Kiel Outdoor Benthocosms (Photo: Mark Lenz)


Frank Melzner

Björn Buchholz

Controlled Parameters

KOB: CO2, temperature, irradiation, nutrients, oxygen, salinity

Research Topics

KOB: responses of benthic communities to environmental shifts/fluctuations in temperature, pH, pCO2, oxygen, nutrients, salinity

Experiment Years
TA Support

Services currently offered by the infrastructure: KOB typically runs relatively long-term experiments on single and interactive global-change effects on benthic marine communities. For example, during the past four years, several experiments were conducted to assess multivariate effects of warming, acidification, eutrophication and hypoxia. More than 30 researcher from Germany, Sweden, The Netherlands, Israel and Portugal were involved. Apart from the mesocosm facility, the following analytical equipment are available for participants of KOB experiments: a) a wide array of microscopic techniques, b) access to culture rooms for additional small-scale studies, c) a flow cytometer for counts and biomass estimates of pico- and nanoplankton, d) an autoanalyser for dissolved nutrient analyses, e) a CHN-analyser for elemental analysis of particulate matter, f) a mass spectrometer to measure stable isotopes (13C, 15N, 34S) as tracers, and g) a SCUBA-diving team and small research vessels.

Support offered under AQUACOSM:

  • Full operation of the KOB facility during experiments

  • Logistical and technical coordination

  • One full time technician

  • Access to lab facilities

  • Coordinated data exchange and data archiving as well as data workshops

Support offered under AQUACOSM-plus: Users will have access to the mesocosms, laboratories and instrumentation described above. Research activities under AQUACOSM will preferably be integrated into larger multi-disciplinary projects, but could also run in parallel or be intercalated between other KOB experiments. A full-time technician for surveillance and servicing of the KOB is available year-round.

TA Modality of Access

Modality of Access under AQUACOSM: A total of 405 person-days is allocated to external users through AQUACOSM Transnational Access provision in years 2-4. An average of 3 persons for 45 days is envisaged each year. Users will have access to the mesocosms, laboratories and instrumentation described above. Research activities under AQUACOSM will preferably be integrated into larger multi-disciplinary projects, but could also run in parallel or be intercalated between other KOB experiments. Projects planned for 2017 – 2019 include the combined effects of warming and sporadic hypoxic upwelling, comparative stress ecology in the Baltic and Mediterranean, impact of bioinvasions, emerging marine diseases.

Modality of Access under AQUACOSM-plus: A total of 500 person-days is allocated to external users through AQUACOSM-plus TA provision. An average of 4-5 persons for 56 days is envisaged per year in two seasons between M10-45.

TA Accommodation

Forschungsverbund Berlin e.V. - Leibniz-Institut für Gewässerökologie und Binnenfischerei
Müggelseedamm 301 and 310
12587 Berlin, Germany