Process of environmetal water quality in O Loan lagoon, Phu Yen province

The paper represents some aspects of the water quality in O Loan lagoon. Two surveys were performed in March and July, 2014 - dry season, and October and November, 2014- rainy season. Due to specificity of O Loan lagoon with narrow estuary, capacity of water exchange is low. A shortage of dissolved oxygen (DO) has led to the pollution of lagoon water quality (4.4.mg/l in dry season and 5.5 mg/l in rainy season).