Submarine groundwater discharge impacts on coastal nutrient biogeochemistry
Submarine groundwater discharge impacts on coastal nutrient biogeochemistry
复制标题
DOI：
10.1038/s43017-021-00152-0
复制
发表时间：
2021-03
影响因子：
42.1
通讯作者：
I. Santos;Xiaogang Chen;A. Lecher;A. Sawyer;N. Moosdorf;V. Rodellas;J. Tamborski;Hyung‐Mi Cho;N. Dimova;R. Sugimoto;S. Bonaglia;Hailong Li;M. Hajati;Ling Li
中科院分区：
文献类型：
--
作者：
I. Santos;Xiaogang Chen;A. Lecher;A. Sawyer;N. Moosdorf;V. Rodellas;J. Tamborski;Hyung‐Mi Cho;N. Dimova;R. Sugimoto;S. Bonaglia;Hailong Li;M. Hajati;Ling Li
海底地下水排放（SGD）连接陆地和海洋系统，但在沿海营养物预算中经常被忽视，因为它很难量化。在这篇综述中，我们研究了全球200多个地点的SGD营养通量，解释了它们对地球化学的影响，并讨论了更广泛的管理意义。在约60%的研究地点，SGD营养盐通量超过河流输入，溶解无机氮的SGD总通量中位数为6.0 mmol m− 2/天，溶解无机磷为0.1 mmol m− 2/天，溶解硅酸盐为6.5 mmol m− 2/天。SGD氮输入（主要以铵和溶解有机氮的形式）通常会减轻沿海沃茨的氮限制，因为SGD往往具有相对于磷的高氮浓度（76%的研究显示N：P值高于Redfield比率）。值得注意的是，大多数研究没有区分盐水和新鲜SGD，尽管它们具有不同的性质。盐水SGD是一种普遍存在的扩散途径，将大部分再循环的营养物质释放到全球沿海沃茨，而新鲜SGD偶尔是新营养物质的局部点源。在水质管理计划中必须考虑SGD产生的营养通量，因为如果管理不当，这些输入可能会促进富营养化。
Submarine groundwater discharge (SGD) links terrestrial and marine systems, but has often been overlooked in coastal nutrient budgets because it is difficult to quantify. In this Review, we examine SGD nutrient fluxes in over 200 locations globally, explain their impact on biogeochemistry and discuss broader management implications. SGD nutrient fluxes exceed river inputs in ~60% of study sites, with median total SGD fluxes of 6.0 mmol m−2per day for dissolved inorganic nitrogen, 0.1 mmol m−2per day for dissolved inorganic phosphorus and 6.5 mmol m−2per day for dissolved silicate. SGD nitrogen input (mostly in the form of ammonium and dissolved organic nitrogen) often mitigates nitrogen limitation in coastal waters, since SGD tends to have high nitrogen concentrations relative to phosphorus (76% of studies showed N:P values above the Redfield ratio). It is notable that most investigations do not distinguish saline and fresh SGD, although they have different properties. Saline SGD is a ubiquitous, diffuse pathway releasing mostly recycled nutrients to global coastal waters, whereas fresh SGD is occasionally a local, point source of new nutrients. SGD-derived nutrient fluxes must be considered in water quality management plans, as these inputs can promote eutrophication if not properly managed.