Abstract
Even though nutrients are important indices for monitoring water environment, they are difficult to observe continuously with a short interval. In this paper, inorganic nitrogen and phosphorus are measured with a submergible in-situ spectrophotometer at two locations at the head of Osaka Bay every 90 minutes to two hours: at a quay in the innermost port bottom water with nutrients of high concentration upwelled due to relatively strong wind; at Kobe Wave Observation Tower, outside of the port, surface concentrations of nutrients fluctuated diurnally because of the effect of both photosynthesis of phytoplankton and horizontal transport of waters which have different constituents of salinity and nutrients.
