The impact of heavy metals on macrobenthic invertebrates in five stations along
the River Nile at Great Cairo (from Helwan to El-Qanater El-Khiria) was studied
during the period from May, 2013 to February, 2014. Physico-chemical characteristics
and heavy metals (iron, manganese, zinc, copper and cadmium) were analyzed in
water. The highest average number (2305 org./m2) of macrobenthic invertebrates was
recorded during spring, while the lowest (642 org./m2) was recorded during summer.
Annelida, Mollusca and Arthropoda were the most dominant groups being 62 %, 34
% and 4 % respectively. Twenty two species and taxa were recorded; Mollusca (13
species) and Annelida (7 species) Arthropoda (2 species).
All the heavy metal concentrations were within the permissible limits except at
Helwan and Hawamdia due to the effect of discharged industrial wastes. The highest
positive correlation was recorded between Arthropoda and iron & zinc, while iron
recorded a negative correlation with Mollusca and Annelida. The principal component
analysis (PCA) showed that the most dominant annelid Limnodrilus spp. had a
positive correlation with cadmium and negative correlation with all other heavy
metals. This indicates that this species can resist the high concentrations of cadmium