In Aquatic Biogeochemistry Research Unit (ABRU), we study how the essential elements of life are cycled in water and sediment. In particular, we focus on carbon, nitrogen, phosphorus and silicon cycling. These are the key nutrients whose availability determine the distribution of life in Earth’s aquatic environments. We study the whole spectrum of aquatic systems, from lakes, through coastal marine environments to the open oceans. We are specialized in the study of sediments, where organic material is decomposed by microbes, releasing nutrients for further cycling in the environment. From 2015-2021, ABRU formed part of the Marine Ecosystems Research Group (MERG) within the Ecosystems and Environment Research Program. The unit was led by Associate Professor Tom Jilbert and Academy of Finland Research Fellows Susanna Hietanen and Karoliina Koho. Since September 2021, Tom Jilbert is affiliated at Faculty of Science (Department of Geosciences and Geography). A link to a new group website will be posted here in the near future.