Ammonia-oxidizing microorganisms compete with phytoplankton for reduced nitrogen in the euphotic zone and provide oxidized nitrogen to other microbes present in the sea. We report 15NH z4 oxidation rate measurements made at 5–20-m resolution using an in situ array and quantification of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in corresponding samples from the upper w...
