三亚近岸海域水体的水质状况分析和评价

近年来三亚水产养殖业和滨海旅游业发展迅速，给三亚近岸水体的水质带来了影响。于2013年1-4月对濒临三亚市区的三亚湾和远离市区的亚龙湾水体中的pH值、溶解氧、磷酸盐、亚硝酸盐、总磷、化学需氧量进行了测定。结果表明，三亚湾水体中的磷酸盐、亚硝酸盐、总磷和化学需氧量的含量均高于亚龙湾，且个别月份间呈显著性差异（P〈0.05）和极显著性差异（P〈0.01）；对水体中pH值和溶解氧的测定表明，2处海湾水体符合国家Ⅰ～Ⅱ类海水水质标准；三亚湾和亚龙湾水体中的磷酸盐浓度分别为0.0152～0.0189 mg/L和0.0082～0.0143 mg/L，分别符合国家Ⅱ～Ⅲ类和Ⅰ类海水水质标准；化学需氧量含量分别为0.528～0.899 mg/L和0.533～1.013 mg/L，均符合国家Ⅰ类海水水质标准。亚龙湾水体水质优于三亚湾，且前者多数海域水体符合国家Ⅰ类海水水质标准；后者多数海域符合国家Ⅱ～Ⅲ类水质标准，少数符合国家Ⅰ类水质标准。

Evaluation and Comparison of Water Quality of Sanya Bay

Water quality was affected by the quick development of coastal tourism and aquaculture of Sanya City in recent years. Some water quality parameters of pH value, dissolved oxygen, phosphate, nitrite, total phosphorus and chemical oxygen demand were measured in coastal water of Sanya Bay, close to urban district, and Yalong Bay, far from urban district, from January to April in 2013 for assessment of water quality of coastal water of Sanya City. Concentrations of phosphate, nitrite, total phosphorus and chemical oxygen demand of coastal water of Sanya Bay were higher than that of Yalong Bay, and there were significant difference （P〈0.05） and very significant difference （P〈0.01） in some months. Value of pH and dissolved oxygen of both bays indicated that water quality of both bays were consistent withⅠ-Ⅱkind sea water quality standards. Phosphate concentration of Sanya Bay and Yalong Bay were 0.015 2-0.018 9 mg/L and 0.008 2-0.014 3 mg/L respectively, which were consistent withⅡ-Ⅲkind andⅠsea water quality standards, respectively. Chemical oxygen demand of Sanya Bay and Yalong Bay were 0.528-0.899 mg/L and 0.533-1.013 mg/L respectively, and both were consistent with Ⅰsea water quality standards. Water quality of coastal water of Yalong Bay was better than that of Sanya Bay, and water quality of former was consistent withⅠkind sea water quality standard in most coastal water area, and the latter was consistent withⅡ-Ⅲkind andⅠkind sea water quality standard in most coastal water area and part coastal water area respectively, in tourism season.