05. MỐI LIÊN HỆ GIỮA THÀNH PHẦN PHIÊU SINH THỰC VẬT VÀ CHẤT LƯỢNG NƯỚC TẠI MỘT SỐ THỦY VỰC TỈNH AN GIANG

Abstract

The study was conducted to evaluate the phytoplankton composition and water quality in some water bodies of An Giang province in 2017-2018. Data on surface water quality and phytoplankton were collected from the Department of Natural Resources and Environment of An Giang province in 2017 - 2018 at 12 locations in Tien and Hau Rivers, Bac Vam Nao and in-field canals. Water quality was assessed by Water Quality Index (WQI) with calculated parameters including dissolved oxygen (DO), total suspended solids (TSS), biological oxygen demand (BOD), chemical oxygen demand (COD), nitrate (N-NO₃^-), orthophosphate (P-PO₄^3-), ammonium (N-NH₄⁺), and coliforms. The findings identified 161 algae species with 94 genera belonging to 7 algae phyla: Cyanophyta (13.66%), Bacillariophyta (24.22%), Chlorophyta (24.22%), Euglenophyta (19.88%), Charophyta (14.91%), Pyrrophyta (1.86%) and Xanthophycophyta (1.24%). The Shannon-Wiener biodiversity index (H’) showed that water bodies were slightly polluted. The water quality index (WQI) classified water resource from heavily polluted water to water that can be used for irrigation purposes. Thus, the H 'and WQI index could be applied to classify water quality. BIO-ENVI analysis showed that the water parameters including pH, DO, TSS, COD, BOD, N-NO₃^-, P-PO₄^3-, and coliforms affected phytoplankton diversity. The results of the this study provide important information regarding the relationship between water quality and phytoplankton in order to select suitable surface water quality parameters for monitoring.