Measurements Obtained in the Project, and the Parameters Controlling the Reaction Rates in the Model Were Estimated. Nitrification Rates According to the Estimations Were Cpmpared with the Results of Nitrification Rates Obtained by Isotopic Measurements. This Comparison Showed the Potential of Using Modeling System and Parameter Estimation as an Alternative Approach to the Hard Isotope Measurements for Estimating Reaction Rates. One-Year Long Observations, Isotope Methods Used and Modeling Approach Have Made Significant Contributions to Scientific Knowledge in the Region. Bacterial Community Structure Have Been Revealed by Culture-Independent Method for the First Time in the Coasts of Turkey. In Addition, Isotope Methods and Metatranscriptom Study Showed That Nitrogen Fixation Is Not a Dominant Process in the Region. And a Biogeochemical Modeling System Has Been Successfully Adapted to the Region.