Ferromanganese nodules as paleoceanographic archives

Nutrient input, eutrophication, oxygen depletion and global warming all place the Baltic Sea’s ecosystem under stress. Effective measures to improve the state of the Baltic Sea require reliable information on the long-term fluctuations in its status and the factors causing the changes. This project is the first study to concentrate on the effects climate change and human activities have had on the ecosystem of the Baltic Sea over the last 7,000 years by analysing the geochemical composition of ferrous manganese nodules. Ferrous manganese nodules are discs or spheres consisting of iron and manganese oxides, which are relatively common on coastal seabeds. The project aims to produce proxy data with an accuracy of 3–20 years with mass spectrometer microanalysis and microbiological analysis. The project also aims to measure the amounts of nutrients and metals that could potentially be released into sea water from the ferrous manganese nodules due to global warming, eutrophication and increasing oxygen depletion.