A very strong purification effect is produced by this bacterial biomass. 

 A great amount of reduced organic compounds is oxidized through this effect, 

 where the compounds are oxidized by oxygen in enzymatic reactions. Accord- 

 ing to the data, in essence we did not observe a significant increase in 

 bacterial biomass. This total value for a large amount of time and for 

 each short time interval is not very great. 



The destruction of organic matter was determined on the basis of oxygen 

 consumption in dark bottles during the incubation of samples for 24 hours 

 at ambient water temperature (Table 2). From this table, it is possible to 

 see that this value for the whole reservoir for the navigable period ranged 

 from 270,000 to 950,000 ton C of organic matter decomposed, with a mean 

 value of 550,000 ton C for 5 years of observations (129 g C/m 2 ) and a fluc- 

 tuation between 64-214 g C/m 2 in different years. 



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