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. ABRU forms part of the Ecosystems and Environment Research Program. The unit contains three senior scientists (Assistant Professor Tom Jilbert, and Academy of Finland Research Fellows Susanna Hietanen and Karoliina Koho), along with several postdocs, PhD students and MSc students.