Assessing the ecological status of Xuan Dai Bay (Phu Yen Province, Vietnam) using AMBI and M-AMBI indices

Abstract

The Xuan Dai Bay, located in Phu Yen Province, Vietnam, is one of the most traditional and important aquaculture areas of the country. Using physico-chemical methods to evaluate the environmental quality of the bay shows that the area is contaminated with nutrients. However, it is necessary to clarify the level of pollution and the impact of polluting factors on biological communities and ecological status in the area. Two marine biotic indices AZTI’s marine biotic index (AMBI) and multivariate-AMBI (M-AMBI) were used to shed light on these issues. This research reveals the outcomes of applying these indicators in evaluating the ecological status in the area. The results show that the environment of the Xuan Dai Bay is being polluted. The most severe pollution level is at stations close to denser farms sites; while the lower pollution is found at stations near the mouth of the bay. The benthic community was imbalanced at all sampling stations, ranging from mild to moderate levels; while the ecological status is moderate, except good-high quality status close to the mouth.