STUDY OF THE ECOLOGICAL CONDITIONS OF MARIUT LAKE MAIN BASIN IN RELATION TO THEIR SUITABILITY FOR FISH LIVING IN THE BASIN

STUDY OF THE ECOLOGICAL CONDITIONS OF MARIUT
LAKE MAIN BASIN IN RELATION TO THEIR SUITABILITY
FOR FISH LIVING IN THE BASIN
ABAZA, KH.M.1
; EL-RAYIS, O.A.2
AND EL-SABROUTI, M.A.2
1
National Institute of Oceanography and Fisheries, Alexandria, Egypt.
2
Oceanography Department, Faculty of Science, Alexandria University.

1
Corresponding author: Dr. Khalid Moh. Abaza. E-mail: [email protected].

Keywords: Lake Mariut, ecological conditions, pollution, fish fauna, salinity, pH, dissolved
oxygen, ammonia and heavy metals.
ABSTRACT
A remarkable decline in the total landed fish catch from Lake Mariut especially from its
Main Basin was observed during the eighties and early nineties of the last century. This
decline is attributed mostly to the ecological changes that took place in the Main Basin;
during the same period; caused by sewage disposal (domestic and industrial waste) and
anoxic conditions in some areas. The present work is a study for the environmental factors
(temperature, salinity, pH, dissolved oxygen and toxic ammonia) and some heavy metals
(Cu, Pb, Cd and Zn) in both water and sediments of the lake Main Basin after the adoption
of an amelioration plan in 1993. Since this plan started, both the water and the sediment
quality of this basin showed a gradual improvement which in turn led to enhancement; to
certain extent; in the suitability degree for the fishes to live in the basin. However, the
present work also indicates that the Southwest side of this basin is the most suitable part for
the living of the aquatic fauna in general specially Cichlids fish as it has better ecological
conditions than the rest of the basin as well as the lowest possible biological effect for the
studied metals in both water and sediments. The slight increase in the fish catch recently
noticed, reflects the impact of the amelioration plan on the basin suitability for the fish
fauna living in it.