Water quality status of Mumbai(Bombay)harbour - an update

Mumbai (Bombay) harbour receiving effluent waste from the discharge points located in an adjoining tidal basin is polluted. The concentrations of inor ganic constituents such as nitrite, nitrate, ammonia acid phosphate monitor ed for a period of 20 months were near critical values. Chlorophyll a conte nt was low. The semidiurnal to diurnal tidal flow in the bay characterised by high velocity movement particularly during ebb-tide, replaces one third of bay water at every cycle per day. This helps to maintain normal dissolve d oxygen concentrations as well as to reduce the organic load as the water moves into the open sea.