The research focus on biodiversity and marine science originated from the combination of the expert knowledge at the Institute of Biology and Environmental Sciences (IBU) and the Institute for Chemistry and Biology of the Marine Environment (ICBM), which has been amended by the Helmholtz Institute for Functional Marine Biodiversity (HIFMB) in 2017. The strength of the IBU relates to its research on phenotypic, physiological, sensory and genetic adaptations to variations in environmental conditions, as well as the analysis of population dynamics and patterns of occurrence of many species with their functional characteristics in relation to resources, disturbances and other environmental factors. The ICBM is renowned for its interdisciplinary environmental research in marine ecosystem, which focuses on the interaction of biogeochemistry and microbial processes, the functional role of marine biodiversity for matter and energy fluxes, as well as land-sea interactions in coastal areas worldwide. As a collaborative institute with the Alfred-Wegener-Institute (AWI), Helmholtz Centre for Polar and Marine Research, HIFMB adds expertise in computational biology, theory of complex systems and adaptations to global change, but especially extends the domain into social science and transdisciplinary approaches to the governance and management of marine ecosystems.

Biodiversity research deals with the adaptive capacity of organisms to the environmental conditions of their habitats on different biological, temporal and spatial scales. This ranges from the molecular biological level to global distribution patterns of many species and their phenotypic and functional variance. Biodiversity research also deals with the analysis of interactions between species and the functional role of biodiversity in the ecosystem. Empirical and theoretical approaches are used to study the evolutionary and ecological processes that govern current patterns of terrestrial and marine biodiversity and their dynamics in times of rapid global change. The synthesis of terrestrial and marine biodiversity research is a unique feature at our university, which is exemplified by the DFG-funded research group "Spatial community ecology in highly dynamic landscapes: from island biogeography to metaecosystems [DynaCom]".

The marine sciences in Oldenburg combine microbiological, ecological, geochemical, physical and modelling approaches that are combined into system analyses to coastal and oceanic research. One focal region is the Wadden Sea, which are in the main venues of one past and two ongoing DFG research units (DynaCom and “Dynamic Deep Subsurface of High-Energy Beaches” [DynaDeep]). Thereby, the university has created a unique baseline for coastal research that is perceived both nationally and internationally. Due to its role as the home institute of the research vessel “Sonne", the ICBM is increasingly devoting itself to questions of ocean research. From 2010 to 2022, the Transregio SFB TRR 51 focused on the functional role of the marine bacteria group Roseobacter, other collaborative projects address the composition of organic compounds in the ocean and sea-air interactions (DFG research unit “Biogeochemical processes and Air–sea exchange in the Sea-Surface microlayer” [BASS]). More recently, this expertise has been linked to the geological, geochemical and paleontological focus of the University Bremen (Marum) leading to a successful collaboration in the light of the "Ocean Floor" excellence cluster. 

The biodiversity and marine research focus is embedded in the research landscape of the Northwest region, with various research institutions contributing expertise in the fields of biodiversity research, ecology, bird migration research and evolutionary biology. Next to the AWI, to which HIFMB belongs, and Marum this includes the Max Planck Institute for Marine Microbiology (MPI-MM, Bremen), the Institute Senckenberg am Meer (SaM Wilhelmshaven), the Leibniz Centre for Tropical Marine Research (ZMT, Bremen) and the Institute of Avian Research "Vogelwarte Helgoland" (IfV, Wilhelmshaven). The regional cooperation manifests itself through eleven established professorships (six with AWI, two with IfV, one each with ZMT, SaM, and the Helmholtz Centre Hereon in Geesthacht), two professors have formal affiliations with MPI-MM. In total, this research focus comprises more than 35 professors and their working groups, which is one of the strongest regional investments in biodiversity and marine research nationally and internationally.