at different ages have varying tolerances 

 to water constituents. The effect of a 

 particular constituent also frequently 

 depends upon the variation in concentration 

 of other constituents. 



A concise statement on the nature of 

 the research and of the available data on 

 toxicity to fishes is given in the Califor- 

 nia "Water Quality Criteria" (17). It reads 

 as follows: "Not only are the references 

 dealing with fish innumerable; they are also 

 individualistic in their approaches to the 

 probleiTi. The conditions under which the nu- 

 merous investigators conducted their experi- 

 ment varied widely and were seldom stand- 

 ardized. Hence, the results of several 

 investigators of the same pollutant may not 

 compare closely. This wide discrepance 

 arises from variations in the species of 

 fish or other organism used, its prior han- 

 dling, the temperature, the dissolved oxygen 

 content, synergistic and antogonistic sub- 

 stances, the hardness and other mineral 

 content of the water, and the time of expo- 

 sure." 



There is a dearth of specific infor- 

 mation on water quality and fish life, and 

 a need for more study on this subject. It 

 was decided to make water tests for only 

 those constituents regarded as harmful to 

 fish life and to make other tests which 

 would be helpful in general water quality 

 evaluation. A study of this nature can 

 concern itself only with those substances 

 which are likely to be present. The reader 

 is referred to reference (.5} for a more 

 complete discussion of toxicity of the var- 

 ious elements and compounds. 



FIELD SAMPLING AND ANALYTICAL 

 PROCEDURES 



Sampling procedures were developed 

 to obtain as nearly a representative sample 

 as possible from the station to be sampled. 

 The procedure had to be within the limita- 

 tions of time, personnel, and equipment 

 available. There was good vertical mixing 

 at all of the stations as determined by 

 temperature and water quality checks at the 

 stations. In the smaller streams no signi- 

 ficant difference in water quality could be 

 found within the cross-section. In the 

 larger streams, there was occasionally a 

 slight chcinge in water quEility across the 

 cross-section because of insufficient 



horizontal mixing below a tributary. Two 

 or three samples were collected at about 

 mid-depth across the cross-section of the 

 stream on each visit. Three samples were 

 collected from the large streams and two 

 from the small streams. The water quality 

 values reported are an average of the con- 

 stituent values found on each visit . 

 Sampling stations were visited from 2 to 4 

 times during the summer months and less 

 frequently during the remainder cf the yeai . 



The water sampler most frequently 

 used was a 1200 ml. improved-type Kemmerer 

 sampler. This sampler is lowered in open 

 position to the desired depth ( in a lake 

 or where the stresim flow is not rapid) and 

 then a messenger is sent down the attached 

 line. This messenger trips a set of hold- 

 ing forks and rubber stoppers move in to 

 seal the cylinder of water within the sam- 

 pler. Sample bottles are carefully filled 

 from the sampler by use of a rubber tube 

 at the sampler base. Sample bottles used 

 were the regular A.P.H.A. B.O.D. bottles, 

 having a ground glass tapered stopper and 

 holding about 300 ml. A weighted, dis- 

 placement type, sampler was used where the 

 current was swift or where the water was 

 shallow. This sampler holds three B.O.D. 

 bottles. During filling, to insure a re- 

 presentative sample, the contents of the 

 bottles are displaced 3 times into the 

 outer container. This type of sampler 

 begins to fill immediately on lowering jind 

 is therefore not suited for deep reservoir 

 or lake samples. 



Water quality determinations were 

 made: (a) in the field at, or shortly 

 after the time of sampling, for those 

 qualities whose value would change on 

 standing; (b) in the laboratory within a 

 day or two following sampling for those 

 determinations not greatly affected by 

 standing or where field testing would be 

 most difficult; and (c) by a private test- 

 ing laboratory for element analysis. All 

 analyses were in accordance with "Standard 

 Methods" (19) unless otherwise noted below. 



Determinations made in the field and 

 the analytical procedure used were as 

 follows : 



a. Temperature - a centigrade ther- 

 mometer, reading to 0.1° C, was 

 dipped in the water when possible. 

 If not, a portable resistance 



23 



