【摘要】 为研究北部湾典型海域关键环境因子的时空分布及其影响因素, 2016年9月至2017年8月对该海域29个站位进行了多学科月度综合调查,分析了该海域主要理化因子的时空分布特征,探讨了水文及生物因素对关键环境因子分布的影响。结果表明:硝氮（NO₃^--N）、活性磷酸盐（SRP）的时空分布具有一致性,高值区主要出现在近岸钦州湾海域,海峡口临近海域及30m等深线以深海域,各月份总有机碳（TOC）、溶解有机碳（DOC）的表底浓度无明显差异（P<0.05）,高温季节溶解氧（DO）、pH的低值区主要位于30m等深线以深的底层海域。DO、pH、NO₃^--N、SRP、溶解硅酸盐（DSi）为影响该海域浮游植物生长的关键理化因子。近岸10m等深线以浅的区域I中, NO₃^--N浓度主要受地表径流带来的陆源污染影响,区域II中NO₃^--N、SRP在秋季受到南海水向北入侵影响,春、冬季受来自琼州海峡的混合水影响, 30m等深线以深的区域III中, NO₃^--N、SRP全年受到南海高盐水的影响。在球形棕囊藻囊体丰度较高的2017年2月至3月,有囊体站位表层的NO₃^--N/SRP显著低于底层（P<0.01）,无囊体站位表底层的NO₃^--N/SRP之间无显著性差异（P>0.05）,棕囊藻赤潮的生消可能是导致春季NO₃^--N、SRP表底分布出现差异的主要原因。更多还原

【Abstract】 A field monthly investigation was conducted in the Beibu Gulf, Guangxi, South China during Sep. 2016 to August 2017 to understand the distributions of different environmental factors, and to analyze various situations affecting the temporal and spatial changes of these environmental factors. We sampled the water in 29 stations, and described the NO₃^--N, SRP（soluble reactive phosphorus）, DSi（dissolved silicate）,pH, dissolved oxygen（DO）, etc. Moreover, the influence of hydrological and biological situation on the distribution was further analyzed. Results show that the spatial distribution and temporal changes ofNO₃^--N was similar to that of SRP and peaked in 3 areas: Qinzhou and Beihai coast, the adjacent waters to the western mouth of Qiongzhou Strait, and the deep water area over 30 m isobath. The TOC（total organic carbon） and DOC（dissolved organic carbon） concentrations were largely stable at all water depth in every station during the investigation（P<0.05）. In the summer, DO and pH were low in NO₃^--N, SRP, and DSi were recognized as the main NO₃^--N concentration was mainly influenced by territorial discharge. In Zone II representing the area from 10 to 30 m isobath, the NO₃^--N and SRP were influenced by mixing water derived from the Qiongzhou Strait current in spring,and by invasive water from South China Sea in autumn. In Zone III that was defined as the area over 30 m isobath, the NO₃^--N and SRP were influenced by invasive water from the South China Sea in the whole year. In NO₃^--N/SRP ratio at surface was much smaller than that at bottom（P<0.01） in the stations where colonies of P. globosa distributed. However,NO₃^--N/SRP ratio between the surface and bottom in the stations having no P.globosa colonies（P>0.05）. Therefore, the outbreak of P. globosa bloom in spring could be the main reason for the NO₃^--N/SRP ratio between the surface and bottom.更多还原