Abstract

Study of the nitrogen (N) forms in Abu-Kir Bay (AKB) revealed that this Bay is occupied with three well distinguished water bodies, one at the southwest (off Tabia pumping station, effluents mainly industrial), off lake Edku outlet (Maadia opening, mainly agricultural drainage water) and off the River Nile (Rosetta) branch outlet (mainly river water mixed with agricultural drainage water). The level of concentration of the total-N was in the following order: Tabia region and Tabia ogutlet > Maadia region and Maadia outlet > Rosetta region and Rosetta outlet. Also, in the first two regions, the level of the concentration in the surface waters was generally, higher relative to that in their corresponding bottom waters, while in Rosetta region the reverse was true. Ammonia was the dominant N-species in the first two regions, while in the last region nitrate was the more dominant. These observations reflect occurrence of deamination and denitrification at rates greater than nitrification in the first two regions. The environmental conditions (DO) studied in those two areas reflect such findings. The contribution of the land based sources with these N-forms to the sea was estimated and presented and reflected that Tabia effluent is the main contribution for N-forms to AKB and for its eutrophication.

Key words: Nitrogen forms, Abu-Kir, Alexandria