C, N, and P Mass Balances in the Bottom Seawater–Surface Sediment Interface in the Reducing Environment due to Anoxic Water of Gamak Bay, Korea

Current mass balances of C, N, and P were estimated using a model (Fluxin = Fluxout + ΔFlux) from Gamak Bay, Korea, in August 2017, where eutrophication reducing conditions are prevalent. To examine the current fluxes particulate organic carbon (POC), nitrogen (PON), phosphorus (POP), sinking re-floating sediment traps deployed, oxygen demand (SOD) chamber experiment ex-situ nutrient incubation conducted, Fick’s first law diffusion was applied. The principal component analysis cluster performed to identify three groups water masses based on characteristics bay, including effects environment due anoxic 14 bottom quality parameters. In (sampling point GA4), SOD20 flux 3047.2 mg O2/m2/d. Additionally, net POC 861.0 C/m2/d, while 131.8% (1134.5 C/m2/d) removed toward overlying water. This indicates that matter had been deposited decomposed as 273.6 C/m2/d. PON 187.9 N/m2/d, whereas 15.8% eluted, 84.2% remained surface sediments. dissolved inorganic (DIN) elution sediments consisted NH4+ (33.7 N/m2/d) NOx− (−4.1 fluxes. Despite POP being 26.0 P/m2/d, 47.7 P/m2/d DIP (179.5% flux) eluted Similar C balance, additional occurred. Therefore, severe (16.5 Okaichi index) with lowest N:P ratio (2.6) GA4 noted. not only freshly exported but also biochemical processes under played an essential role remarkable source–particularly P–for Korea.