Burial pattern of carbon, nitrogen and phosphorus in the soft bottom sediments of the Baltic Sea

The burial pattern of carbon, nitrogen and phosphorus in soft bottom sedime nts from all sub-basins of the Baltic Sea has been investigated. The highes t total concentrations of carbon and nitrogen are found in the central deep part of the Baltic proper. The inorganic concentration of carbon is normal ly far below 1% in the entire Baltic Sea except for some localities with an oxic conditions where authigenic precipitation of mixed manganese carbonate s occurs, for example, the eastern Gotland deep. Manganese seems to be of e ssential importance for such precipitation. As in the case for carbon, a do minant proportion of the nitrogen found in the sediments is organically bou nd. For phosphorus, on the other hand, a dominant proportion is inorganical ly bound. The highest total concentrations are found in the eastern part of Gulf of Finland and in the well-oxidized sediments of the Bothnian Bay and Bothnia Sea. The organic C/N ratio is very stable vertically through the s ediment very stable at each location indicating that the degradation of the organic matter in the sediment proceeds in a C/N proportion. The organic C /P ratio within the sediment departs considerably from the Redfield ratio, mainly due to more or less instantaneous releases of easily hydrolyzable or ganic phosphorus molecules.