population of squawfish in Roosevelt Lake is equivalent to the maxi- 

 mvm population of squawfish in Cultue Lake* Apparently, however, 

 there is a muoh greater population of chubs in Roosevelt Lake than 

 in Cultus Lake, since only 27 chubs were reported caught in 7 years 

 of fishing at Cultus Lake whereas 50 chubs were caught in the one 

 season's fishing at Roosevelt Lake. 



SUMMART 



1« Roosevelt Lake, situated in northeastern Washington, is the 

 storage resei-voir behind Grand Coulee Dam* 



2* The surrounding shoreline has been established as a National 

 Park for the recreational benefit of the public €uid is easily accessible 

 by good roads* 



3* The greater part of the reservoir lies in a rain belt which 

 supports evergreen forests* 



4* Various physical and biological aspects of the lake were in- 

 vestigated including temperatures, oxygen, carbon dioxide, hydroxides, 

 carbonates and bioarbonates, pH, turbidity, plemkton, and fish popu- 

 lations* 



6* Tlie most surprising discovery was the almost complete lack of 

 thermal gradient, a very unusual condition for a leike of this depth* 



6. All physical factors of the water appeared favorable to fish 

 with the exception of extreme turbidity of the water* 



7* plankton hauls revealed fair-to-good abundance in the lower 

 reservoir as compared to rather sparse concentrations in the upper 

 stretches* 



8» Further study should be made of the turbidity of the lake 

 and of the meager plankton output of the upper region in order to 

 determine whether or not the 1948 season was made unusual by the heavy 

 spring flood* 



9* Fish sampling at Roosevelt Lake in 1948 consisted of 30 gill 

 net-nights of fishing* An average of 7*4 fish were caught per net-night < 



10* Slightly larger catches were made fishing at the bottom 

 than at ihe surface* 



11* Species caught were squawfish, chubs, suckers, shiners, perch, 

 tench, sunfish, sculpin, and carp* 



12* In addition to the above species sport fishermen claim to 

 have caught the following: Rainbow, brook, cutthroat, dolly varden 

 and kamloops trout; kokanee or landlocked bluebaok salmon; whitefish; 

 largeraouth and smallmouth bass* 



13* A comparison of the Roosevelt Lake gill net catches with 

 those made at Cultus Lake reveals that the concentration of squawfish 

 in Roosevelt Lake in 1948 was at least as great as that in Cultus 

 lake, in 1935* 



26 



