Abstract
Nitrate is the major chemical form of N-nutrient to sustain primary production in Changjiang Estuary and adjacent seawaters. We employed δ15N-NO3− and δ18O-NO3− to constrain the source, cycling, and sink of nitrate in early spring. Both δ15N-NO3− and δ18O-NO3− differentiate significantly among Changjiang Diluted Water (CDW), Yellow Sea Coastal Current (YSCC), and Taiwan Warm Current (TWC). In coastal areas, nitrate distribution and its isotopes are mainly affected by Changjiang inputs. Chemical fertilizers and sewage & manure originated nitrate jointly contribute the most nitrate in CDW. In offshore areas, nitrification contributes 44 ± 21% of the nitrate in YSCC and 17 ± 16% in TWC; assimilation is the dominant process to remove nitrate in TWC (35 ± 16%). Overall, nitrification and assimilation are the key nitrate cycling processes in early spring and co-shape the offshore distribution pattern of nitrate and its dual isotopes.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
