Present Status and Long-Term Changes of Water Quality Characteristics in Heavily Polluted Mediterranean Lagoon, Lake Mariut, Egypt

Abstract

The present status, a long term change of water quality characteristics besides
metal pollution load (Fe, Mn, Zn, Cu and Cd) in water of a heavily polluted
Mediterranean Lake (Mariut Lake northwest of Egypt) were investigated. Water
quality characteristics varied in a wide range among the different basins. Depending
on collecting data; the agricultural and domestic sewage drained from Al-Qalaa Drain
responsible for the most drastic deterioration status in main basin of the lake.
Meanwhile, Aquaculture Basin has the highest values of salinity and consequently
both major cations and anions. Ratio of N:P indicated of potential N limits on
phytoplankton growth. Almost, the values of all studied metals are higher than
standard permissible levels. The contamination index (Cd) revealed that the order of
pollution increasing as WB < SB < AQB < MB. PCA analyses showed that most of
nutrient salts associated with heavy metals were responsible for heavily polluted
zones. Cluster analyses showed that, main basin has the most polluted aspects
depending on concentration of studying parameters followed by a moderate polluted
aquaculture basin then low polluted western and southern basins.