Benthic Macroinvertebrate Diversity Index as Water Quality Indicator of Govantes River in Vigan City, Ilocos Sur

Abstract

This study was conducted to determine the water quality of Govates River i Wigan Cay, locos Sur using the diversity index (DI) of the river's benthic macroinvertebrates as an instrument for evaluation from May - October 2001. This research adopted the natural substrate sampling method devised hy Mitchell and Stapp. Six sampling stations were established during the course ofthe study: Station A in Brgy. II, Station B in Brgy. [II, Sration C in Rrgy. Pantay Daya, Station D in Pantay Fatima, Station E in eastern portion of Brgy Pantay Laud, and Station F in western portion of Brgy Pontay I. and a total ofeighteen species ofbenthic macroinvertebrates were collected from the river. ANOVA results indicated significant differences among and between the average number (taxa richess) and average distrilui indices (SCh) of benthic macroinvertebrates of the six stations. Their computed diversity indices (DI) were all in the lowest bracket of the scale in qualifying water. All the indices indicted poor water quality. In as much as Govantes River is being revived as a prime aquaculture site, it was recommended that an investigation should be
conducted to find out the causes of the poor water quality of the river said appropriate measures should he undertaken to prevent progressive deterioration of the river. Furthermore, there should be a yearly monitoring of the quality of the river water. It was also recommended that other biological components of the river should be
tupped as pollution indicators such as plankton.