p. 17 - 21 DETERMINATIONS OF THE HORIZONTAL TURBULENT DIFFUSION COEFFICIENTS IN THE ROMANIAN COASTAL WATERS Vasile Diaconu and Adriana Popa Romanian Marine Research Institute Constanta Abstract Using the field data on the horizontal distribution of the salinity in the plumes generated by several types of waste water discharges, the apparent eddy diffusivity was determined by means of the Fick and Richardson solutions for the steady state diffusion.