Marine microbial life is of enormous, but often underestimated importance for the environmental conditions on Earth: microorganisms have a considerable influence on geochemical cycles such as the carbon, nitrogen and sulfur cycles, but also on the oxygen content of the atmosphere. Complex yet poorly understood interactions between microbes play a particularly important role here. In particular the working groups in geochemistry, microbiology and mathematical modeling closely work together to explore the role of microorganisms in the large-scale fluxes of energy and matter between the sea, atmosphere and land. For this research, the institute hosts a world-wide unique infrastructure, in particular large experimental mesocosms, several high-performance mass spectrometers, a clean room and a proteogenomics laboratory.

Pollutants or fertilizers that flow from the land into the sea pose a burden on marine ecosystems in many places. While riverine fluxes towards the ocean are relatively well understood, relatively little is known about groundwater discharging below the surface into the sea - and which substances enter the marine environment along this path. The subsurface of the beach seems to be an efficient bioreactor that alters both the fresh groundwater and the circulating seawater prior to discharging into the sea. Marine researchers of ICBM work closely with colleagues of the Institute of Biology and Environmental Sciences (IBU) at the University of Oldenburg to better understand this little-explored transition between land and sea.

Climate change and human use threaten the diversity of life in the seas. So far, however, relatively little is known about the extent to which marine ecosystems have already changed and to what extent biodiversity is affected by human influence. Biodiversity research at ICBM is particularly concerned with the interactions between species and the complex processes within coastal, marine ecosystems. Also the connectivity between biodiversity on land and in the ocean is a research topic of ICBM together with IBU at the University of Oldenburg.

The state of the marine realm is directly influenced by human actions and at the same time humans depend on the ecosystem services of the oceans and coasts. International programs (e.g., UN's Sustainability Development Goals or the European Marine Strategy Framework Directive) and national programs (e.g., MARE:N, DAM) are related to the protection and use of the oceans. Since its establishment, ICBM has performed research regarding the endangerment of coasts and the sea through human actions. Currently, the input, transport, transformation and fate of plastic waste including microplastics, as well as increasing inputs of anthropogenic trace elements, persistent organic pollutants (POPs), emerging pollutants (EPs) and maritime traffic emission into the coastal zone represent important research fields. Sustainable use of the oceans is also addressed by various field based studies assessing the effects of human activities (e.g., fishing and tourism) on biodiversity and ecosystem functioning. These activities are carried out in a number of individual and collaborative projects (see descriptions below) in close collaboration with regional, national and international partners. The wide range of analytical and technical expertise that exists in the ICBM is instrumental to perform this research. This includes strengthened expertise on marine conservation and governance, as well as conceptual and coupled hydrodynamic-biogeochemical ocean modeling. Additionally, ICBM’s recently established research Center for Marine Sensors (Wilhelmshaven) develops innovative sensor technologies to support sustainable use of natural water resources and empower citizens and societal stakeholders in environmental stewardship. In addition, the ICBM operates the Spiekeroog Coastal Observatory, a mid-size infrastructure of national importance.