Institute of Marine Science and Technology, Shandong University, Qingdao 266237, China.
Institute of Marine Science and Technology, Shandong University, Qingdao 266237, China; State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China.
Sci Total Environ. 2021 Nov 10;794:148702. doi: 10.1016/j.scitotenv.2021.148702. Epub 2021 Jun 25.
The Bohai and Yellow seas are marginal seas of the western North Pacific, characterized by coastal eutrophication and populated coastlines. In this work, six survey datasets collected between 2011 and 2018 were used to investigate the excess of dissolved inorganic nitrogen (DIN) related to soluble reactive phosphorus (SRP), referred to as N*, in the Bohai and Yellow seas. High N* of more than 5 μmol kg occurred mostly in the Changjiang and Yellow River plumes and/or near the Jiangsu coast. Away from these river plumes and the Jiangsu coast, however, N* usually ranged from -2.5 to 1.0 μmol kg. Combining our field data and previously published data, we found that N* in the Bohai and Yellow seas increased in the 1990s and 2000s, likely caused by the combined effect of atmospheric nitrogen deposition increase and the Kuroshio N* rise. In the 2010s, however, the coastal N* increases stopped. Based on a N*-budgeting approach, marine N (either from in situ decomposition of marine organic matters or from the open seas via current inputs) and non-marine N (either from riverine inputs or from local atmospheric nitrogen deposition) were distinguished. Marine N accounted for 51% ± 38% of DIN in the Bohai Sea and 67% ± 37% of DIN in the Yellow Sea. Although this is a regional study, we suggest that accumulation of atmospheric nitrogen along oceanic circulation pathways dominates the decadal evolution of coastal eutrophication. These findings and new insights may improve management of eutrophication in these two important marginal seas, and will also improve our understanding of nutrient dynamics in other marine systems.
渤海和黄海是西北太平洋的边缘海，具有沿岸富营养化和人口密集的海岸线的特点。在这项工作中，我们使用了 2011 年至 2018 年期间收集的六个调查数据集，来研究渤海和黄海中与可溶解反应性磷（SRP）相关的过量溶解无机氮（DIN），即 N*。高 N*（超过 5 μmol kg）主要发生在长江和黄河的羽状流及其附近的江苏省海岸。然而，远离这些河流羽状流和江苏省海岸，N通常在-2.5 到 1.0 μmol kg 之间。结合我们的现场数据和以前发表的数据，我们发现，渤海和黄海的 N在 20 世纪 90 年代和 2000 年代增加了，这可能是大气氮沉积增加和黑潮 N上升的综合作用造成的。然而，在 21 世纪 10 年代，沿海 N的增加停止了。基于 N*-预算方法，区分了海洋氮（来自海洋有机物的原位分解或通过海流输入从开阔海域输入）和非海洋氮（来自河流输入或当地大气氮沉积）。海洋氮占渤海 DIN 的 51%±38%，占黄海 DIN 的 67%±37%。尽管这是一项区域性研究，但我们认为，沿海洋环流途径积累的大气氮主导了沿海富营养化的年代际演变。这些发现和新的见解可能会改善对这两个重要边缘海富营养化的管理，并将提高我们对其他海洋系统中营养动态的理解。
