In Situ Technologies

Scientists: F. Wenzhöfer, Antje Boetius, Ralf Hoffmann, Felix Janssen; Lab support: Martina Alisch, Mirja Meiners, Rafael Stiens, Erika Weiz-Bersch; Technical support: Volker Asendorf, Karin Hohmann, Axel Nordhausen, Fabian Schramm (SeaTechnology) and the MPI workshops


The sediment surface is characterized by steep gradients and an extensive spatial and temporal heterogeneity. Measurements with high temporal and spatial resolution are crucial for the understanding of early diagenesis, microbe-environment interactions, and benthic fluxes. To determine microbial conversion rates in sediments, and to get insights into their regulation, activity measurements must be complemented by the characterization of the habitat, its microenvironments, the determination of transport phenomena, and substrate availability. The microprofiler unit enables the in situ quantification of such processes in environments where core retrieval severely alters the sediment, such as in gas-laden cold seeps, the deep sea, or highly dynamic environments. more ...

In situ deployment of a profiler with 11 sensors.
Closeup showing microsensors attached to profiler.

Benthic Chamber Module

In the highly heterogeneous ocean ecosystem, the sediment-bottom water interface represents a boundary zone that connects the two oceanic realms - the sediment and the water column. At the seafloor, the sediment-water interface is one of the most important transition zones for solute exchange, both in time and space. The benthic chamber module enables in situ measurements of the total exchange rates (e.g oxygen, methane, nutrients, DIC) between the sediment and the water column. This measurement integrates all relevant solute transport processes (diffusion, advection, and fauna-mediated transport). more .....

benthic chambers
Benthic chambers.
benthic chamber
Benthic chamber incubation on bacterial mat.

Eddy Correlation

The sediment-water interface is one of the most important boundary layers of the earth system with crucial filter functions for the mass exchange between the seafloor and the water column. One of the most important exchange processes across this layer is the oxygen flux, which is a fundamental control factor for the biogeochemical activity in the sediment. The eddy correlation system (ECS) allows the measuring of exchange rates across the water-sediment interface in a non-invasive manner, providing direct measurements with temporal resolution of minutes, and a spatial resolution of several meters. more ....

Eddy Correlation
Bringing the Eddy into the water.
deepsea Eddy
The deepsea Eddy.

Multi Fiber Optode (MuFO)

Oxygen concentrations in the marine environment are highly variable on a wide span of temporal and spatial scales. Thus, for monitoring oxygen dynamics in the sea, continuous measurements at many different positions are often desirable. The MuFO was developed to enable multiple oxygen measurements in the water column and in sediments with a high temporal resolution in combination with a high degree of spatial flexibility. more .....

In Situ MuFo
In situ deployment of the MuFo (left) in the Black Sea, a closeup (middle), and full view of the instrument on board (right).

Planar Optode in situ Module

The distribution of oxygen in marine sediments is often highly heterogeneous due to factors like advection, bioturbation / bioirrigation, plant roots, and benthic photosynthesis. The planar optode module enables in situ exploration of the oxygen dynamics at the sediment surface. The sediment oxygen distribution is recorded as 2D-images with a high temporal resolution, giving insights into the spatial heterogeneity, and its evolution over time. more ......

Planar Optode
In situ deployment of the Planar Optode.


The INSINC is a device to measure in situ sulfate reduction.

INSINC in situ deployment, measuring sulfate reduction in a microbial mat.

Instrument-Lift "Colossos"

Colossos can be used as a "lift" to attach instruments and bring them to the bottom of the ocean. Here, an ROV can detach the instruments and deploy them for measurements, incubations, etc.

The instrument lift "Colossos".
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