为研究渤海中部区域的沉积物中能参与界面交换的生物可利用磷 (BAP) 的潜在含量，本实验以渤海中部海域的5个区域(唐山沿岸、秦皇岛沿岸、渤海东北部海域、渤海海峡、渤海西南部海域)为对象，采用分级浸取法，测定了23个采样点的沉积物样品中磷的组分、含量，并计算潜在BAP含量，分析了其分布特性及影响因素。结果显示，渤海中部海域表层沉积物中无机磷 (IP)是渤海中部海域表层沉积物中总磷 (TP)的主要存在形式，唐山沿岸、秦皇岛沿岸、渤海东北部海域、渤海海峡、渤海西南部海域这5个区域沉积物中，IP含量平均分别占其 TP含量的78.39%、79.06%、71.46%、84.60%和81.46%，而有机磷 (OP)则均占较小的比例。IP均以碎屑磷 (De-P)为主要赋存形态，平均分别占TP的54.02%、52.12%、33.33%、69.41%和57.28%，IP中各形态磷的含量顺序：碎屑磷 (De-P)> 闭蓄态磷 (Oc-P)>铁/铝吸附态磷 (Fe/Al-P)>钙结合态磷 (Ca-P)>弱吸附态磷 (Ex-P)。河流输入、沉积物粒度和沉积环境是影响渤海中部海域表层沉积物中不同形态磷含量及分布的主要因素。研究表明，唐山沿岸、秦皇岛沿岸、渤海东北部海域、渤海西南部海域表层沉积物中潜在的BAP含量平均分别占 TP 的44.77%、46.94%、64.87%和40.54%，具备较强的向水体中释放磷的潜力。本研究为深入研究渤海中部海域营养物质循环和补充机制及沉积物对海洋水体磷的贡献上限提供理论参考。

Phosphorus is an important biogenic element necessary for the growth and reproduction of marine phytoplankton, and it is also the basic element of marine primary productivity and food chain. The potential content of bioavailable phosphorus (BAP) in sediments that can participate in interface exchange depends on the form of phosphorus in sediments, while there are few studies in the central region of the Bohai Sea. In this study, five areas in the central Bohai Sea (Tangshan coast, Qinhuangdao coast, northeastern Bohai Sea, Bohai Strait, and southwestern Bohai Sea) were selected as the research objects. The composition and content of phosphorus in the sediment samples at 23 sampling points were determined by the hierarchical leaching method, and the potential BAP content was calculated. The distribution characteristics and influencing factors were analyzed. The results showed that the inorganic phosphorus (IP) in the surface sediments of the central Bohai Sea was the main form of total phosphorus (TP) in the surface sediments of the central Bohai Sea. The IP contents in the sediments of Tangshan coast, Qinhuangdao coast, northeastern Bohai Sea, Bohai Strait and southwestern Bohai Sea accounted for 78.39%, 79.06%, 71.46%, 84.60% and 81.46% of the TP content, respectively, while the organic phosphorus (OP) accounted for a small proportion. Detrital phosphorus (De-P) was the main occurrence form of IP, accounting for 54.02%, 52.12%, 33.33%, 69.41% and 57.28% of TP on average, respectively. The content of phosphorus in each form of IP was in the order of De-P > Oc-P > Fe/Al-P > Ca-P > Ex-P. River input, sediment grain size and sedimentary environment are the main factors affecting the content and distribution of different forms of phosphorus in surface sediments in the central Bohai Sea. According to the analysis of potential BAP content in sediments, the potential BAP content in the surface sediments of Tangshan coast, Qinhuangdao coast, northeast Bohai Sea and southwest Bohai Sea accounted for 44.77%, 46.94%, 64.87% and 40.54% of TP, respectively, which had strong potential to release phosphorus into water. This study provides a theoretical reference for further study of nutrient cycling and supplement mechanism in the central Bohai Sea and the upper limit of sediment contribution to phosphorus in marine water.

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上海市科委地方能力建设项目 (21010502200)；上海市人才发展资金 (B1-5404-19-0002)