The samples were kept in laboratory for 48 h for hardening. The preserved organisms were then transferred to a Petri dish and washed with tap water to remove the remaining washable detritus
and mud. The samples were then cleaned with distilled water and benthic invertebrates were separated from each using sorting needle and fine forcep. Finally, benthic fauna were sorted into major taxonomic groups using a magnifying glass (65 mm, Optical InstrumentCo.) and low power microscope (magnification: 10 × 2.5) wherever necessary. Then all available organisms were counted
and identified up to genera according to Wetzel and Lickens (1983).