Assessment of the effect of submarine groundwater discharge on the biological production by the radon tracer in Wakasa-Reinan basin area

我们估计输入的淡水和营养盐通过海底地下水排放（SGD）到奥巴马湾使用氡（222 Rn）和盐度的质量平衡模型。结果表明，进入海湾的SGD占总淡水通量的4-44%。夏季，由于河流流量急剧减少，SGD趋于较高。溶解无机氮、溶解无机磷和溶解无机硅酸盐的通量分别约占陆源总通量的39%、58%和37%。SGD的磷供应对奥巴马湾的生物生产具有重要意义，因为该湾的初级生产磷含量低于磷限量。

We estimated the input of freshwater and nutrients via submarine groundwater discharge (SGD) into Obama Bay using mass balance model of radon (222Rn) and salinity. As a result, the volume of SGD into the bay was estimated to be 4-44% of the faction of SGD in total freshwater flux. The SGD tended to be high in summer, because river water discharge decreased drastically. The nutrient fluxes from SGD were approximately 39%, 58% and 37% of total terrestrial fluxes dissolved inorganic nitrogen, dissolved inorganic phosphorous and dissolved inorganic silicate, respectively. The phosphorous supply from SGD was suggested to be important in the biological production in Obama Bay which was under the phosphorous limit for primary production.