Abstract:
Biological monitoring is more popular than chemical monitoring due to low cost, effectiveness and it is environmentally friendly. RBP, one of the biological monitoring tool is popular due to its efficiency, low cost and time saving. Present study was carried out to investigate the application of RBP (II) developed by United States Environmental Protection Agency using macro invertebrates, in surface runoff of freshwater bodies of head streams of Nilwala river basin, in Matara district. Four sites located in the upper and middle catchment areas of Nilwala river basin were sampled using artificial substrate samplers and conventional sampler from July 1999 to May 2000. Collected macro invertebrates were identified up to family level. The metric used in RBP (II) and the protocol used in Global Environmental Monitoring System (GEMS)/ Water system, were used to calculate points for each site. Water quality imparity of study sites was classified into four broad categories based on final percentage categories. Site ST 4 was moderately impaired while site ST 2 was non-impaired. Occurrence of the number of ephemeropteran, plecopteran and trichopteran families were higher in sites ST 1 and ST 2. Rapid Bioassesment Protocol (II) was successful in differentiating the water quality of the study sites.
