Study on Water Quality and Biodiversity of Benthos in Chi River

Abstract

The objectives of this study were to investigate water quality in term of physical, chemical, biological characteristics and diversity of benthic fauna in Chi River. The area of study included 6 sampling sites along the Chi River which flew through Maha Sarakham Province. The each sampling site was sampled for 6 times
(during January to November, 2015). The parameters included temperature, transparency, pH, dissolved oxygen (DO), biochemical oxygen demand (BOD), NO3- -N, PO4 3-  and coli form bacteria. In addition, the Benthos diversity which focused on investigating Diversity Index (H’) Evenness Value (J') and Taxa Richness (R) was also studied. The result of the study were found that; water quality parameters were as followed: The average water temperature was 21.20-34.00ºC, transparency was 15.00-80.00 cm., pH was 6.84-10.00, dissolved oxygen (DO) was 2.00-9.80 mg/l, biochemical oxygen demand (BOD) was 1.00-6.07 mg/l, NO3 - -N was 0.40-1.13 mg/l,PO4 3- -was 0.08-0.45 mg/l and coliform bacteria was 1.24-6.25x 103 MPN/100 ml. The Benthos diversity found that; there were 3 Phylums in the Chi river, such as Phylum Arthropoda, Phylum Mollusca and Phylum Annelida, The diversity index(H') is 2.28, the average of Evenness Value (J') is 0.56(56%) and Taxa Richness (R) is 2.54. According to studies, water quality in the Chi River when compared with surface water quality standards. This research findings were indicated that water quality of the Chi River was classified as being in the type 3 based on the surface water quality standards. The diversity of benthic depended on water quality. Furthermore, the most of benthic habitats were lived in good quality water. Chironomus sp. which tolerated
in low quality water and found in polluted water resource. Therefore, benthic animals can be used as indicators of water quality.