EUTROPHICATION IN THE COASTAL WATERS OF ALEXANDRIA FOLLOWING THE INCREASE IN PHOSPHORUS LOAD

Samples from the coastal waters of Alexandria during 1991-1993 indicat e a remarkable increase in the phosphorus load from 870 to 1140 kg y(- 1) compared to 567 kg y(-1) in 1986 raising the average phosphorus fro m 1.01 to 1.47 mu M compared to 0.44 pM during 1986. Consequently, ave rage chlorophyll a levels raises from 9.5 pg l(-1) in 1991 to 12.05 mu g l(-1) in 1993 with distinctive peaks during summer (maximum dischar ge period). The phosphorus residence time (183- 223 days) is sufficien t for causing intermittent blooms and eutrophication. Anoxic condition s during 1991-1993 were accompanied by fish and benthos mortality.