The project will identify and ecologically evaluate concrete possibilities for active climate protection in the context of marine nature conservation measures. STATUS is working on three main topics: 1) Expansion and evaluation of biogenic reefs in the Baltic Sea, 2) Measurement of their carbon storage potential using selected examples, 3) Modelling of the CO2 balance under current and future conditions for the entire area in the German Baltic Sea. A continuous and results-orientated transfer of knowledge on blue carbon ecosystems to the Federal Agency for Nature Conservation (BfN) is to take place. The conservation-relevant knowledge gaps for the German seas to be investigated in the project were identified on the basis of the knowledge of the Leibniz Institute for Baltic Sea Research on the distribution of biogenic reefs in the German Baltic Sea as well as the BfN-DEFINE literature study and with the support of an expert network established in this context. In STATUS, sublittoral mussel beds are to be investigated. The aim of this project is to address identified knowledge gaps (research and assessment) in the Baltic Sea and to develop a basis for concrete options for action. The selected focus areas dovetail the areas of research, application and implementation in order to meet the urgent need for action in the areas of climate protection, biodiversity conservation and marine nature conservation due to the climate and biodiversity crisis.