EBEL, DAWXEY, and MONK : THERMAL TOLERANCE 



Table 5. — Mean values^ of lethal exposure time (in min- 

 utesT for coho salmon that had been acclimated to 20° C 

 water temperature and then subjected to various in- 

 creases in water temperature and saturation of nitrogen 

 gas. 



Table 7. — Mean values^ of lethal exposure time (in min- 

 utes) for hatchery spring chinook salmon that had been 

 acclimated to 20° C water temperature and then sub- 

 jected to various increases in water temperature and 

 saturation of nitrogen gas. 



Dead fish 

 in sample 



Level 



of 

 gasb 



Lethal exposure timft of 

 various temperatures (" C) 



20 



27 



Dead fish 

 in sample 



Level 



of 

 gosb 



Lethal exposure time at 

 various temperatures (" C) 



27 



a Mean of replicated tests. 



b NN = normal saturation (100%) of nitrogen gas in occlimation and 

 test tanks; 

 NS = normal saturation in acclimation tank and supersoturotion 



(125-130%) in test tanks; 

 SN = supersoturotion in acclimation tank and normal saturation in 



test tanks; 

 SS = supersaturation in acclimation and test tanks. 



a Mean of replicated tests. 



b NN = norma! saturation (100%) of nitrogen gas in acclimation and 

 test tanks; 

 NS = norma! soturation in acclimation tank and supersoturotion 



(125-130%) in test tanks; 

 SN = supersoturotion in acclimation tank ond normal soturotion In 



test tanks; 

 SS = supersoturotion in acclimation and test tanks. 



Table 6. — Mean values" of lethal exposure time (in min- 

 utes) for hatchery spring chinook salmon that had been 

 acclimated to 15° C water temperature and then sub- 

 jected to various increases in water temperature and 

 saturation of nitrogen gas. 



Dead fish 

 in sample 



Level 



of 

 gasb 



Lethal exposure time at 

 various temperatures (° C) 



20 



23 



25 



27 



One fish 



Three fish 



Half of sample 



All of sample 



NN 

 NS 

 SN 

 SS 



NN 

 NS 

 SN 

 SS 



NN 

 NS 

 SN 

 SS 



NN 

 NS 

 SN 

 SS 



510 

 450 

 32.5 



585 

 30 



375 



390 



30 



525 



90.5 

 210 

 30 

 20.5 



255 



198 



245 



80 



360 

 255 

 370 

 122.5 



1,020 

 275 

 700 

 399 



28 



22 

 16 5 

 75 

 6.5 



55 



45 



9 



II 



66 

 52.5 

 39.5 

 16.5 



88.5 

 97 

 78.5 

 50 



5 



4.5 

 4 

 3 



9 



8.5 

 6.5 

 4 



115 

 10.5 

 9 

 6 



30.5 

 25 

 19.5 

 40.5 



a Mean of replicated tests. 



b NN = normol saturation (100%) of nitrogen gas in acclimation and 

 test tanks; 

 NS = normal soturotion in acclimation tank ond supersaturation 



(125-130%) in test tanks; 

 SN = supersaturation in occlimation tank and normal soturotion in 



test tanks; 

 SS = supersaturation in acclimation and test tanks. 



Table 8. — Mean values" of lethal exposure time (in min- 

 utes) for wild spring chinook salmon that had been 

 acclimated to 10° C water temperature and then sub- 

 jected to various increases in water temperature and 

 saturation of nitrogen gas. 



Dead fish 

 in sample 



Level 



of 

 gasb 



Lethal exposure time at 

 various temperatures {° C) 



20 



23 



25 



Three fish 



Half of sample 



All of sample 



NN 

 NS 

 SN 

 SS 



NN 

 NS 

 SN 

 SS 



NN 

 NS 

 SN 

 SS 



NN 

 NS 

 SN 

 SS 



870 



660 



27 



61 118 9 4 



645 463 163 17 3 



98 312 4 2 1 



35 68 10 3 I 



192.5 27 



465 43 



80 9 



71.5 6 



82.5 5 



195 4 



7.5 2 



7.5 3 



193 27 



165 43 



80 9 



600 780 71 6 



a Mean of replicated tests. 



b NN = norma! soturotion (100%) of nitrogen gas in acclimation and 

 test tanks; 

 NS = normal soturotion in occlimation tank and supersaturation 



(125-130%) in test tanks; 

 SN = supersaturation in occlimation tank and normal saturation in 



test tanks; 

 SS = supersoturotion in acclimation and test tanks. 



837 



