MASS-BALANCE OF TOTAL PHOSPHORUS IN THE IZMIT-BAY

Elements needed to obtain mass balance of a nutrient in a coastal sea by direct methods are: movement of water masses (current field), estim ates of location and intensity of all major nutrient sources, estimate of nutrient inflow from the neighboring sea and a reliable estimate o f the nutrient extinction in the water column. In practice, the intens ity of major sources and extinction of nutrient water column are seldo m known. Therefore inverse methods for the transport equation are empl oyed to obtain mass balance. Mass balance of total phosphorus in the I zmit Bay for March 1994 suggests that total source from the coast is a bout 1.3 t P/day. The extinction constant is 12 days. The majority of TP originating from the land-based sources of the bay proper ends up i n the lower layer of the bay. A small part is transported into the Mar mara sea.