This is a study of tritium. radiocarbon, dissolved helium- neon, and argon in the Black Sea. Earlier data show that there is measurable tritium below 1700m while between 700m and 1700m there is none. This can be explained by the sinking of Mediterranean water to form the Black Sea bottom water. Further measurements of tritium in the bottom will allow us to construct the evolution of this isotope, and to test the models based on the previous observations. Detailed dissolved helium measurements will provide information on the constancy of the sedimental flux, on the accumulation of radiogenic 3He and on the rate of upwelling from the bottom layer. These measurements will be used to model the input and mixing rates of the Mediterranean input as well as to search for the predicted effects of diminished rover input on the mass balance of the Black Sea.