Estimating the input of submarine groundwater discharge (SGD) and SGD-derived nutrients in Geoje Bay, Korea using 222Rn-Si mass balance model

In order to evaluate the main source of nutrients for maintaining the high production in shellfish farming bay, we have measured Rn-222 activities and the concentrations of nutrients in stream water, seawater, and coastal ground-water around Geoje Bay, one of the largest cultivation areas of oyster in the southern sea of Korea in April 2013. Using the Rn-222 and Si mass balance model, the residence time of bay seawater was about 5 days and the submarine groundwater discharge (SGD) into the bay was estimated to be approximately 1.8 x 10(6) m(3) d(-1). The SGD-derived nutrient fluxes contributed approximately 54% for DIN, 5% for DIP, and 50% for DSi of total nutrient input entering into the bay. Thus, our results suggest that SGD is the major source of nutrients in Geoje Bay, and SGD-derived nutrients are very important to support the biological production of this shellfish farming bay. (C) 2016 Elsevier Ltd. All rights reserved.