2002 Volume 3 Issue 2 Pages 77-82
Water mass and water properties (such as nutrients, particulate matter and organic matter) at the intake sea area of Suruga Bay deep seawater off Yaizu were investigated in November 1999. Water temperature at the depths of 350 m and 700 m were 10 °C and 5 °C, respectively. Salinity showed a maximum at the depth of 150 m and a minimum at the depth of 500 m. The seawater at both intake depths were classified into a subpolar intermediate depth water by these characteristics of temperature and salinity. The concentrations of nutrients increased with depth, and at 400 m and 700 m depths the concentrations were 26.1, μM nitrate, 1.9 μM phosphate, 58.3 μM silicate and 35.6, μM nitrate, 2.6, μM phosphate, 103 μM silicate, respectively. This indicates that the deep seawater was rich in nutrients. Although the concentration of suspended matter of deep seawater was higher than that of surface seawater probably due to resuspended bottom sediments, number of bacteria, and concentrations of dissolved and particulate organic carbon of deep seawater were significantly lower than those of surface seawater.
