†Department of Earth and Planetary Sciences, University of California Santa Cruz, 1156 High Street, Santa Cruz, California 95064, United States.
‡Earth System Science, University of California Irvine, Irvine, California 92617, United States.
Environ Sci Technol. 2015 Jun 2;49(11):6665-73. doi: 10.1021/acs.est.5b00909. Epub 2015 May 19.
We quantified groundwater discharge and associated nutrient fluxes to Monterey Bay, California, during the wet and dry seasons using excess (224)Ra as a tracer. Bioassay incubation experiments were conducted to document the response of bloom-forming phytoplankton to submarine groundwater discharge (SGD) input. Our data indicate that the high nutrient content (nitrate and silica) in groundwater can stimulate the growth of bloom-forming phytoplankton. The elevated concentrations of nitrate in groundwater around Monterey Bay are consistent with agriculture, landfill, and rural housing, which are the primary land-uses in the area surrounding the study site. These findings indicate that SGD acts as a continual source of nutrients that can feed bloom-forming phytoplankton at our study site, constituting a nonpoint source of anthropogenic nutrients to Monterey Bay.
我们使用过剩的（224）Ra 作为示踪剂，量化了加利福尼亚州蒙特雷湾在雨季和旱季的地下水排泄和相关养分通量。通过生物测定培养实验记录了形成水华的浮游植物对海底地下水排泄（SGD）输入的响应。我们的数据表明，地下水的高营养含量（硝酸盐和硅）可以刺激形成水华的浮游植物的生长。蒙特雷湾周围地下水中的硝酸盐浓度升高与农业、垃圾填埋场和农村住房相一致，这些是研究地点周围地区的主要土地利用方式。这些发现表明，SGD 是可以为我们研究地点的形成水华的浮游植物提供养分的持续来源，构成了向蒙特雷湾输入人为养分的非点源。
