Society and ecological health depend on ecological processes and functions, the so-called ecosystem functions. These functions are essential for all levels of organisms and a result of their interactions with the environment. Benthic habitats, some of the most productive and diverse ecosystems on Earth, are of global importance for biogeochemical cycles. Each of the three major benthic communities, macrofauna, meiofauna and microorganisms, have key roles in these processes.

Currently, the anthropogenic pressures from nutrient overloading with oxygen depletion and pollution by heavy metals are potent threats to the diversity and functioning of these communities in the Baltic Sea and ultimately on the provision of ecosystem goods and services, that affect human wellbeing of societies in this region. Crucial, unanswered questions within Baltic Sea ecology are how anthropogenic pressure affects benthic community structure and how interactions between macrofauna, meiofana and microbial community mediate sediment ecosystem functions under different environmental conditions.

To bridge these knowledge gaps, this project examines how Baltic Sea sediment meiofauna, the most diverse and abundant metazoans in aquatic sediment, and microbial diversity interact and are structured by double exposure to two important stressors, hypoxia and heavy metal exposure. We particularly investigate how and to what extent this affects important benthic ecosystem functions relevant to sediment nitrogen cycling. Taking advantage of the multidisciplinary range of our expertise, analyses combine ecological, ecotoxicological, biogeochemical methods and environmental genomics approaches. Drawing on insurance and resilience theory we furthermore investigate whether the loss of diversity in the sediment communities reduces the resilience and recovery of benthic ecosystems processes.

Outcomes will directly relate to the directives initiated by the European community, the Water Framework Directive and the Marine Strategy Framework Directive and the Baltic Sea Action Plan that address diversity of bioindicators, chemical status and quality of the marine environment to achieve Good Environmental Status in regards to qualitative descriptors, including biological diversity, eutrophication and contaminants.