Structure of Fish Assemblage in Relation to Some Ecological factors in Himreen Dam Lake, Iraq

Abstract

Spatial and temporal variability of fish assemblage in Himreen Lake was studied from summer 2014 to spring 2015. Water temperature, electrical conductivity, dissolved oxygen, transparency and potential hydrogen ion were measured from three sites in the Lake. Several fishing methods were adopted to collect fish including; gill nets, cast net, hook and line and hand net. The results showed that the fish assemblage consisted of 19 species representing seven families. Number of species increased in summer and spring and sharply decreased in winter. Luciobarbus grypus was the most abundant species comprising 23.6% of the catch, followed by Carassius auratus (20.07%) and Cyprinus carpio (11.39%). The dominance (D 3) value for the main three abundant species was 55.06%. The overall values of diversity index ranged from 1.71 in winter to 2.43 in summer, richness index from 2.4 in winter to 2.94 in summer and evenness index from 0.71 in winter to 0.84 in autumn. Associations between the distribution of fish species and the environmental variables were quantified by using canonical correspondence analysis (CCA).