Part I is the report on the oceanographical observations of the Nakami in the summer of 1933. Though the distinguished difference of salinity was observed in the horizontal distribution of the upper layers at the oceanographical investigation of 1929 on board of R. M. S. Syumpu-maru, in the present case the salinity is averaged horizontally showing the value about 24‰. It indicates the fact that the invasion of the main sea water into the bay is obstructed.
The quantities in silicate and phosphate in this summer are as much as two or three times comparing with that in 1929. Oxygen content dissolved in water is above 5c.c./L in the layers of 0 and 3m. depth and below 2c.c./L in the bottom layer.