Abstract
Nitrogen nutrition of natural populations of phytoplankton in surface waters of the western North Pacific was investigated with an intracellular 15NH4+‐partitioning technique. At three oligotrophic stations, rate of 15N incorporation into macromolecular components was almost identical with uptake rate, suggesting that phytoplankton are not nitrogen deficient. 15N accumulation in extractable components was inferred from data obtained at two other oligotrophic stations. At these stations, phytoplankton growth is apparently limited by nitrogen supply. At three mesotrophic stations, a similar but less pronounced 15N accumulation in extractable components occurred, which may be attributed to enhanced ammonium uptake caused by the exposure of phytoplankton grown on nitrate to high concentrations of ammonium.
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.
