Future Work 



The identification of several of the groups of animals presented 

 serious difficulties. It is probable that some of the organisms have not 

 yet been described. 



The life histories and environmented. requirements of many of the 

 species ai^ imperfectly known. Increased knowledge in this respect wovild 

 be tremendously important in selecting indicator organisms for assessing 

 water q\iality. 



Additional work is warranted to give a better understanding 

 of the existing conditions in the Sacramento River. A tremendous amount 

 of data was collected during this sxirvey. An evaluation should be made 

 of the many physical conditions, such as flxw, teii5)erature , dissolved 

 oxygen, etc., and. their relationships to the biology of the river. This 

 includes both benthic organisms and plankton. 



It is expected that taxonomic information and data on range exten- 

 sions and ecology will be reported in Depairtment of Fish and Game publi- 

 cations or other technical journals. 



Futvire biologiceJ. monitoring of the Sacramento River is neces- 

 B&ry to detect changes in the river environment. In view of the presently 

 anticipated development of the Sacramento Val 1 ey , it is suggested that 

 comprehensive investigations be made at intervals of about five years. 

 Such investigations may be restricted to 10 or 12 stations occupied 

 seasonally. 



The extreme variability of the dissolved oxygen content of water 

 in gravels is a factor that warrants further investigation. Adequate 

 dissolved oxygen is particularly important in development of snimnn and 

 steellieewL eggs in the gravel riffles. 



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