These air temperatures were tabulated by 

 monthly and yearly meauis for l8 selected 

 stations in Washington, one in Idaho and 

 nine in Oregon. 



WATER QUALITY EFFECTS ON FISHES 



Water quality affects anadromous 

 fishes in different ways. It may, if ad- 

 verse, discourage the adults in their 

 upstream migration; kill them by toxicity 

 or disease before they reach the spawning 

 grounds; cause them to not spawn when at 

 the spawning beds; destroy their eggs by 

 providing an environment unfavorable for 

 hatching; or it may cause the newly hatched 

 fish to die through destruction of the 

 young fish itself or its food supply. A 

 search of the literature for specific water 

 quality constituents and their effect on 

 anadromous fishes was not very fruitful. 

 Different species of fish and the same fish 

 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 vagrant 

 nature of the research and of the available 

 data on toxicity to fishes is given in the 

 California "Water Quality Criteria" (12). 

 It reads as follows: "Not only are the 

 references dealing with fish innumerable; 

 they are also individualistic in their 

 approaches to the problem. The conditions 

 under which the numerous investigators 

 conducted their experiment varied widely 

 and were seldom standardized. Hence, the 

 results of several investigators of the 

 same pollutant may not compare closely. 

 This wise discrepancy arises from varia- 

 tions in the species of fish or other 

 organism used, its prior handling, the tem- 

 perature, the dissolved -oxygen content, 

 synergistic and antagonistic substances, 

 the hardness and other mineral content of 

 the water, and the time of exposure." 



There is a dearth of specific infor- 

 mation on water quality and fish life and a 

 need for more study on this subject. In 

 deteimining what water tests should be made 

 in this survey, it was decided to make 

 those where there were reports of the con- 

 stituent being of possible hann to fish 

 life and to make other tests whose values 

 would be helpful in general water quality 



evaluation. (See succeeding section for 

 tests actually made and the analytical 

 procedure used. ) 



Ellis (7) describes the following 

 waters , in the absence of toxic pollutants , 

 as being favorable to a good mixed fish 

 fauna: 



a. Dissolved oxygen, not less than 

 5 p. p.m. 



b. pH, approximately 6.7 to 8.6, 

 with an extreme range of 6.3 to 

 9.0. 



c. Specific conductance at 25° C, 

 150 to 500 mho X 10-0, with a 

 maximum of 1,000 to 20,000 mho x 

 10-6 penaissible for streams in 

 western alkaline areas. 



d. Free carbon dioxide, not over 

 3 cc. per liter. 



e. Anmonla, not over I.5 p. p.m. 



f. Siispended solids, such that the 

 millionth intensity level for 

 light penetration will not be 

 less than 5 meters. 



The IntemationsLL Pacific Salmon 

 Fisheries Commission in their upper Fraser 

 River studies (8), state the following in 

 regard to water temperatures: "Sockeye 

 salmon in the Fraser system have a decreas- 

 ing temperature tolerance as they approach 

 their spawning grounds. On the spawning 

 beds, large numbers of sockeye will die 

 without spawning if mean water temperature 

 exceeds 63" F. Farther down the migration 

 route, at Hells Gate, temperatures of 70° F. 

 have caused no apparent ill effects. . . . 

 CoLumnaris disease is known to beccana extreme- 

 ly virulent at temperatures in excess of 

 70° F." Their studies indicate that sock- 

 eye can be expected to die when mean water 

 temperatures exceed 68° F. for periods of 

 several days. 



The Water Pollution Research Board, 

 London, in their 195'4- report (9), had the 

 following observations to make on effects 

 of pollution on fish: 



a. Ammonia undissociated is more 

 toxic than is the ammonium ion; 

 toxicity of ammonia is effected 



11 



