DESCRIPTION OF STUDY AREA 



The upper Klamath Basin of Oregon is the 

 general study area (Fig. 1) with surrounding peaks 

 ranging to about 10,000 ft above sea level. The basin 

 floor is situated at about 4100 above sea level. This 

 area is located between Crater Lake and Klamath 

 Lake at about 42° 40' north latitude and 121° 56' 

 west longitude. The terrain was formed mainly by 

 volcanic activity which resulted in various deposi- 

 tions of ash, lava, and pumice and was modified by 

 glaciation and errosion. Most of the watershed does 

 not appear to have noteworthy amounts of organic 

 material in the soil and this is covered primarily by 

 lodgepole pine at upper elevations and ponderosa 

 pine at lower elevations. Altitude increases rapidly 

 from the valley (basin) floor to the top of steep- 

 sided foothills. Human habitation is very scarce 

 except on the valley floor where a few cattle ranches 

 or summer homes dot the area. The nearest settle- 

 ments are Chiloquin and Ft. Klamath. 



Many springs can be found at the base of these 

 steep-sided hills. Typically the springs have a basin 

 area 10 m or more across, and collectively discharge 

 several hundred gpm of crystal clear water. These 

 discharges form rivers which flow swiftly across the 

 valley floor into Agency Lake or Klamath Lake. The 

 water is alkaline ranging from pH 7.4-8.0, but is 

 poorly buffered with only about 30-40 ppm total 

 alkalinity (as CaC0 3 ). Dissolved oxygen in the spring 

 water is typically above 90% of the saturation value 

 for that altitude. Water temperatures are rather vari- 



SPRING 



TO CRATER LAKE 

 ♦ 

 \ 

 FORT 



KLAMATH 



TO CHEMULT 



4 SAMPLING 

 W STATION 



FIG. 1 Project area map. 

 38 Rouck 



CHILOQUIN 



able between the springs and in one instance ranges 

 from6°Cto11 o C(42-51°F)within100 mof each other. 

 There are many spring-fed rivers in this basin, 

 but only five are being monitored at present. These 

 are Spring Creek, Williamson River, Crooked Creek, 

 Fort Creek and Wood River. Additionally, the springs 

 supplying water to the Klamath Hatchery are being 

 monitored. Each of these is discussed below, and 

 the data are presented in Table 1. 



Klamath Hatchery Spring and Crooked Creek 



Circumstances at the Klamath Hatchery have 

 been of concern for some time because several fish 

 kills have occurred previously and were attributed 

 to gas bubble disease. Another kill began in early 

 August of 1974; Eagle Lake rainbow trout of fry size 

 were dying and emboli were evident in the afferent 

 arteries of the gills. Few emphysema were evident. 

 Dying fish were cultured for common infectious 

 disease agents but the results were all negative. The 

 possibility of involvement with chemical toxicity 

 was not ruled out, but its likelihood was remote. 

 Therefore, it was concluded that the fish were dying 

 of gas bubble disease from supersaturation. 



The suspect water supply is drawn from the 

 North settling basin which is uncovered and con- 

 tains several springs. Total dissolved gas pressure 

 was about 50 mm Hg above air pressure (AP) or 

 about 1.076 atm. In the raceways where fish were 

 dying, the AP was only 35 mm Hg above air pressure 

 or about 1.053 atm. Possibly as many as 25% of these 

 fry died at these relatively low hyperbaric levels. 



Remedial action was taken to degas the water 

 by cascading it into buckets and almost immediately 

 thereafter the fish kill abated. 



Many springs contribute to Crooked Creek in 

 addition to the hyperbaric hatchery effluent. Dis- 

 solved gas pressures were measured about 1 mile 

 below the hatchery and showed a AP of 46 mm Hg 

 or about 1.070 atm. As noted above, a slightly lower 

 level of supersaturation was found in the hatchery 

 where fish were dying of gas bubble disease. 



Gas pressures were measured again at about 

 monthly intervals. The August and September data 

 indicate that total dissolved gas pressure in the 

 spring is dropping gradually, i.e., AP=50->-48-*36. 

 Possibly this trend will prove to be a cyclic pattern 

 because fish kills here have occurred both earlier 

 and later than August. Whatever the case, these 

 results indicate that the dissolved gas pressure in 

 this spring water can vary significantly without an 

 equally evident change in temperature. 



Damage to fish or invertebrates in this stream 

 was not readily apparent by qualitative observations. 

 Trout were feeding in the stream at the surface and 

 their light color did not indicate stress. Examination 

 of the benthic fauna revealed sculpins, larval 



