本文利用2022年在汕头南澳岛周边海域4个航次的调查数据，对表层水体中营养盐、叶绿素a和化学需氧量等重要水质参数的分布特征以及水体的富营养化状况进行了分析研究。结果表明，南澳岛周边海域营养盐浓度总体呈西北向东南递减，冬季营养盐浓度显著高于其他季节。夏季，南澳岛周边海域呈现高叶绿素低营养盐的特征，说明该季节浮游植物对营养盐的生物吸收作用明显；南澳岛青澳湾附近海域的营养盐出现高值，可能源于附近海水浴场的生活污水排放。而在其他季节，溶解无机氮（Dissolved Inorganic Nitrogen, DIN）的最高值均出现在榕江口附近，说明陆源径流的排放造成高DIN浓度的主要因素；溶解无机磷（Dissolved inorganic phosphorus, DIP）的最高值主要出现在柘林湾的网箱养殖区，说明网箱养殖是造成DIP高值的主要因素。尽管秋季在外海站位出现相对N限制，但整体来看，该海域营养盐结构基本平衡，未出现营养盐绝对限制的情况。用富营养化指数（Eutrophication index，EI）、营养质量指数（Nutrient quality index，NQI）和营养状态指数（Trophic index，TRIX）对该海域的富营养化状况进行评估显示，富营养化最严重的区域在夏季出现在青澳湾附近，其它季节则出现在柘林湾湾口和榕江河口附近，需要重视夏季旅游热点区域生活污水对近岸海水的影响。富营养化综合评价指数与DIN极显著正相关，与盐度显著负相关，反映陆源径流是该海域富营养化主要诱因。EI严重低估了夏季低营养盐高叶绿素水体的富营养化程度， TRIX指数有效指示了水体富营养化的时空差异，更适合此类“低营养盐-高叶绿素”的海域。本研究结果有助于全面了解南澳周边海域水环境质量的时空特征，为海域环境治理和资源利用提供科学依据。

The key environmental factors (nutrients, Chl a, COD, et al.) and eutrophication indexes was investigated in the surface water surrounding the Nan’ao Island in 2022. The seasonal change of nutrient concentration was significant, which gradually declined from northwest to southeast in the surrounding region of Nan’ao Island. The nutrients concentration was significantly higher in winter than other seasons. During summer, the nutrient concentration was high near the Qin’ao Bay, which possibly originated from the discharge of domestic wastewater. The highest dissolved inorganic nitrogen(DIN) was found near the estuary of Rongjiang River and the highest dissolved inorganic phosphorus(DIP) was found near the net cage aquaculture zone in the Zhelin Bay. This phenomenon suggested that the river input increased the nitrogen loading and the cage aquaculture increased the phosphorus loading in this region. The seawater showed high Chl a and low nutrient in summer, suggesting the strong bio-assimilation effect of phytoplankton on the nutrient. The structure of nutrients was generally balanced, and no absolute limitation was detected for nitrogen, phosphorus or silicate. Nitrogen nutrient was relatively limit in the offshore region in autumn. According to the Eutrophication index(EI), Nutrient quality index(NQI), and trophic index(TRIX), the highest eutrophic status was generally near the Zhelin Bay and Rongjiang River estuary. However, the region near Qing’ao Bay showed high eutrophic status in summer. With the fast development of tourism, the influence of domestic wastewater should be paid more attention in Nan’ao Island. The eutrophication indices showed a significantly positive correlation with DIN and a negative correlation with salinity. River discharge should be the main reason causing water eutrophication in this region. The eutrophic status might be underestimated using EI index in the waters with low-nutrient and high-chlorophyll during summer. The results contribute to a better understanding of the water quality status surrounding the Nan’ao Island and provide basic data for environment management and marine resource utilization.