CHAPTER V. SUMMARY AND RECOMMENDATIONS 



A study of the biological conditions in the Sacramento River 

 was made over the period April i960 through June I961. The piirposes were 

 to establish a '^ase line" of present conditions, provide the basis against 

 which future changes can be measured, and provide information for use in 

 setting appropriate reqxiirements for present and future waste discharges. 



Siaanary 



Water temperatures in Keswick Reservoir were relatively constant 

 throxighout the period of investigation (50 - 55*^)- During winter months, 

 temperatvtres decrease as the water moves downstream. Temperatures rise 

 below Keswick during the remainder of the year and reach highest values 

 just above Sacramento. 



Dissolved oxygen concentrations are high in the upper reach 

 and gradually decrease throughout the length of the river. Large varia- 

 tions of dissolved oxygen were foxmd at closely spaced sampling points 

 at several of the riffle stations. In the gravels, the lower oxygen levels 

 were usually associated with higher silt concentrations. 



The transparency of water in the Sacramento River generally 

 decreased from the upper area to the mouth. 



Attached plants are uncommon in the river proper. A species 

 of moss (Fissideus) is present in the riffles in the upper section of 

 the river. Emergents such as Typba suid Scirpus axe present along the 

 beinks in the lower sections. Benthic algae are present in the riffles 

 in the upper reach of the river, but were i-arely found in other areas. 



At least 165 sepsurate species of animals, representing 10 phyla, 

 were collected from 29 river stations during the stirvey. The dominant 



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