Field visits findings: (a) Greenish to brownish putrified algae copvering large areas of water surface under which small dead fishes were detected, (b) Large quantities of moldy waste products were picked up on both sides of the lake, (c) Dreger and suction machines worked in the lake during the mass mortality, (d) Variations of the lake water color in different locations. (e) Mass mortality of different species of fish scattered in farm ponds and along their bridges as well as in Manzala water; f: A. regius, g: D. labtax., h: Sparus aurata.