In the past, investigators have used the ratio of phytoplankton photo- 

 synthesis to oxygen consumption by seston and by dissolved organic matter 

 ($/D). This ratio is also a rather variable index, and apparently, can 

 not be used for the evaluation of pollution. Much better results are ob- 

 tained by the use of the ratio $/R, where R is total consumption of oxygen 

 by the water and sediments. Figure 5, the ratio <J>/D and $/R for the 

 Pripyat River are compared. The ratio $/R serves as a better indicator 

 of pollution than the ratio of <J>/D (Figure 5, Stations 1 and 7). 



Thus 

 reflect 

 surably 

 the degr 

 cause of 

 masses, 

 stances, 

 crease i 

 able dev 



, the struct 

 the biologic 

 to pollution 

 ee of pollut 



the diversi 

 some variati 



an increase 

 s noted. It 

 i at ion from 



ural peculiarities and functiona 

 al activity of suspended substan 

 . As a result, they may be used 

 ion and estimation of water qual 

 ty of pollutant types and variat 

 on in measured values can be exp 

 in the index value is observed, 

 is important, however, that in 

 the average clean water statisti 



1 indices of seston 

 ces, and react mea- 



for evaluation of 

 ity. However, be- 

 ions between water 

 ected. In some in- 



and in others a de- 

 all the cases, a not- 

 cal norm is observed, 



12 34 5 6 



7 8 9 



STATION 



10 11 12 



Figure 5. The ratio of $/D and $/R on the Pripyat River. 



156 



