GENERAL CHARACTERISTICS OF FAR EASTERN SEAS 699 



from 350 to between 20 and 40 mg/m 3 , and of silicon from the range 1,000 to 

 1,300 down to 200 to 300 mg/m 3 . Phytoplankton production was calculated 

 from the amount of plant food as 75 g of carbon under 1 m 2 (D. Smetanin, 

 1959). Moreover, if in the coastal waters off Kamchatka the 'yield' during 

 the spring reaches 125 g/m 3 in terms of carbon, in the open regions of the 

 Ocean it falls to 5 or 6 g/m 3 , i.e. by about 25 times. Vertical changes in the 

 content of oxygen and plant food and in the ranges of temperature and 

 salinity in spring at various places in the central Kuril-Kamchatka trench 

 are given in Tables 284, 285 and 286. 



Table 284 



Depth Oxygen Phosphorus Silicon 



m (percentage) (mg/m 3 ) (mg/m 3 ) 



Table 285 



Depth Temperature Salinity Oxygen 



m °C % (percentage) pH 



Table 286 



Oxygen Phosphate Ammonium 



Depth Temperature (percentage) phosphorus nitrogen Silicon 



m °C (mg/m 3 ) (mg/m 3 ) (mg/m 3 



