THE SEA OF OKHOTSK 



789 



micro-organisms decreases with depth by some thousands of times (1,500 

 to 5,500). 



Kriss also mentions the immense number (maybe thousands per 1 ml of 

 water) of suspended articles in the water, from a few to a hundred microns 



140 



150 



160 



Fig. 393. Isoxigenes of the near-bottom layer of Sea of Okhotsk 



(Ushakov). 



in size. The huge absorption surface of these small bodies is, according to this 

 investigator, most significant for an understanding of the biological and 

 physicochemical processes taking place in the water column. 



Plankton 



The list of the phytoplankton of the Sea of Okhotsk contains 290 species of 



diatoms and 58 species of peridineans (P. Ushakov, 1953). 



According to the data of A. Zhuze and G. Semina (1955) diatomaceous 

 sea-weeds are markedly predominant in the Sea of Okhotsk phytoplankton, 

 comprising from 70 to 100 per cent of its biomass. This latter may reach 



