Localization of the organic matter production and degradation in two different estuaries

Abstract

Physical and chemical processes related to primary production of the estuaries of two rivers with different water regime are considered with special attention to their spatial and seasonal variability. Both production and degradation of the organic matter are quantitatively evaluated on the data of non-conservative variation of dissolved inorganic phosphorus concentration in the process of the river water dilution. Contribution of recycling to the phosphorus balance and the estuarine waters productivity is estimated. The organic matter degradation prevailed in the internal part of both estuaries, but its production dominated in their external parts, with a tendency of production lowering and degradation strengthening from spring to autumn. Utilization of the re-mineralized phosphorus in the external estuaries increased their potential productivity by 20-50%, provided by the terrigenous flux with the river water.