Nutrient-rich submarine groundwater discharge fuels the largest green tide in the world
Nutrient-rich submarine groundwater discharge fuels the largest green tide in the world
复制标题
营养丰富的海底地下水排放助长了世界上最大的绿潮
DOI：
10.1016/j.scitotenv.2020.144845
复制
发表时间：
2021
影响因子：
9.8
通讯作者：
Zhigang Yu
中科院分区：
文献类型：
--
作者：
Shibin Zhao;Bochao Xu;Qinzhen Yao;William C. Burnett;Matthew A. Charette;Rongguo Su;Ergang Lian;Zhigang Yu
2007年至今，我国南黄海每年都发生世界上最大的“绿色潮”（Ulva prolifera）爆发。目前，江苏省周围的沿海地区（苏北浅滩地区）被认为是这些巨大的绿色潮汐水华的起源点。高营养需求，但低河流排放量和其他输入的组合表明，有一个显着的通量在这一地区的海底地下水排放（SGD）。利用镭质量平衡模型，估算了该区域的SGD通量为（0.7-1.4）× 109 m3 d-1（6.1-12 cm d-1），处于全球SGD通量的高端。从地理上看，苏北浅滩不到整个南黄海面积的5%，而我们计算的浅滩区域的SGD通量是以前记录的整个南黄海的3倍。因此，苏北浅滩可能是一个SGD热点，在SGD相关物质通量中起着重要作用。与来自当地河流、大气沉降和人类活动的输入相比，SGD来源的营养盐是支持大型藻类生长的主要源项。我们特别强调，这类地区是浅的，密集混合，生物污染，桑迪或泥泞的大量生物灌溉，可能有更高的风险遭受有害的生态问题，即使有限的陆地径流。·苏北浅滩的海底地下水排放通量估计高达1.4 × 10 9 m3 d −1。·苏北浅滩SGD通量约为南黄海其余海区的3倍。·与SGD相关的营养盐进入浅滩区可能主要支持U.增殖。
One of the largest “green tide” ( Ulva prolifera ) outbreaks in the world has occurred every year from 2007 to present in the Southern Yellow Sea, China. Currently, the coastal area around Jiangsu Province (Subei Shoal region) is thought to be the origination point of these giant green tide blooms. The combination of high nutrient demand but low river discharge and other inputs suggests that there is a significant flux of submarine groundwater discharge (SGD) in this area. By using a radium mass balance model, we estimated the SGD flux in the area to be (0.7–1.4) × 10 9 m 3 d −1 (6.1–12 cm d −1 ), at the high end of SGD fluxes worldwide. Geographically, Subei Shoal is less than 5% of the entire Southern Yellow Sea area, while our calculated SGD flux just for the shoal area is ~3 times larger than previously documented for the whole Southern Yellow Sea. Therefore, Subei Shoal may be considered a SGD hotspot that plays an important role in SGD associated material fluxes. Compared to inputs from local rivers, atmospheric deposition, and anthropogenic activities, SGD-derived nutrients are the main source term that can support the growth of macroalgae. We specifically highlight that this type of areas that are shallow, intensively mixed, anthropogenically polluted, sandy or muddy with heavy bio-irrigation, may have a higher risk of suffering harmful ecological problems, even with limited terrestrial runoff. • Submarine groundwater discharge (SGD) fluxes of the Subei Shoal were estimated to be as high as 1.4 × 10 9 m 3 d −1 . • The Subei Shoal SGD flux is ~3 times that of the remaining South Yellow Sea. • SGD associated nutrients to the shoal area may dominantly support the growth of U. prolifera .