Research on the impact of seawater intrusion on nitrogen (N) cycling in coastal estuarine ecosystems is crucial; however, there is still a lack of relevant research conducted under in-situ field conditions. The effects of elevated salinity on N cycling processes and microbiomes were examined in situ seawater intrusion experiments conducted from 2019 to 2021 in the Nakdong River Estuary (South Korea), where an estuarine dam reg...

Regenerated nitrogen (N) cycling was studied in a turbid and nutrient-rich estuary located in the southeast region of the Yellow Sea (Yeongsan River Estuary; YRE), in order to elucidate the biogeochemical consequences of coastal development. Ammonium regeneration and potential uptake rates were measured from March 2012 to June 2013 using 15 N tracer techniques. Size fractionation suggested that small-sized bacteria (<0.7 μm),...

The effects of seasonal hypoxia on sediment-water interface nitrogen (N) transformations in Jinhae Bay were examined from 2015 to 2019. The rates of benthic denitrification, anaerobic ammonium oxidation (anammox), dissimilatory nitrate reduction to ammonium (DNRA), nutrient exchange, and sediment oxygen consumption were measured seasonally. The oxygen (O 2 ) and hydrogen sulfide (H 2 S) depth profiles were measured using micro...

We conducted continuous‐flow experiments on intact sediment cores from Laguna Madre, Sabine Lake, East Matagorda Bay, and Nueces Estuary to evaluate internal nitrogen (N) sources, sinks, and retention mechanisms in Texas estuaries having different salinities. Mean ammonium (NH 4 + ) flux ranged from slight uptake (negative values) to NH 4 + production rates of about 300 µmol m −2 h −1 (units used for all N rates) and increased...

Net sediment‐water interface fluxes of oxygen, dinitrogen, and dissolved inorganic carbon and nitrogen were determined in shallow, subtidal estuarine sediments (Galveston Bay, Texas) using in situ benthic chamber incubations. Diel variability in the sediment oxygen demand and in the flux of dinitrogen were attributable to the occurrence of benthic photosynthesis. Daytime denitrification rates exceeded nighttime rates. During d...