Comparative study of aquatic insects' communities for water quality assessment in Sunagi Peres and Sungai Bubu, Hulu Terengganu, Terengganu

Abstract

The study was done for four months (August-November, 2006) usmg the biomonitoring approach based on aquatic insects in relation to water physico­ chemical parameters to assess, classify and compare the water quality of Sungai Peres and Sungai Bubu. A total of 3409 individuals of aquatic insects representing 42 families from nine orders were collected using disturbance-removal sampling technique. The total number of aquatic individuals did not differ significantly between two streams but showed a higher abundance at the upstreams (Z = -2.519, P = 0.012) compared to downstreams. The Ephemeroptera, Plecoptera, Trichoptera (EPT) Index and EPT to Chironornidae ratio (EPT:C) showed that the pollution-sensitive EPT were present in high diversity and abundance, especially at the upstreams, while the distribution of resistant Chironomidae was higher at downstreams.