The Yeongsan River estuary (YRE) is located
downstream of a dam housing an artificial lake on the southwestern
coast of Korea. Intermittent discharges of lake water through
dam gates control the water level of the lake. This study
compares fluxes of dissolved nutrients in discharged water with
those of submarine groundwater discharge (SGD) occurring in
the YRE in July and October 2008. With the exception of
dissolved inorganic phosphorus (DIP) which limits primary
production, nutrient concentrations in the YRE are controlled
mainly by conservative mixing between lake water and open
ocean water during periods of lake water discharge. In
comparison with lake water discharge, the magnitude of SGD,
based on a 222Rn mass balance model, is relatively small (about
1.5×105 m3 day-1 in July and about 30% higher in October) and
dependent on the water elevation in the lake. However, SGD
contributes considerably to the input of DIP when discharge of
lake water is halted. Our study shows that SGD is more
important in the delivery of biogeochemical components into
estuaries that are obstructed by artificial dams.