The reservior is still reverse thermoclined this time of year, cold water on top first <20+, warmer on bottom
Kokes like 53>55d F water, they are a temperature oriented rather than depth oriented fish. This time of year, the fish just suspend there when not feeding, no desire to fight over food, there is no koke food source at that temp zone now.
But to feed, they go where their food source is at and that is algae which this time of year is very shallow, less than 10 ft with the low sun angle, algae do fine in cold 40d F water. The fish come up from below to feed in the morning as the algae rises to the surface to collect sun for their photosynthisis. Few to no Mysis relicta shrimp in Merwin
So this time of year, the kokes are active and the most aggressive while feeding, no koke sex on their tiny nit brains yet. But their small bodies product little excess energy in 40d F water to fight for food. They have no fat storage yet for energy bursts.
Got to stir up their nit brain, bright flashy spinners, wedding rings etc early season. My favorite go to tubes/squids/hoockies are very hit and miss for me early cold water season. Bright flashy spinner or Smile blades in front of a hoochie helps
Fish for them less than 10ft in Merwin until the air temps>, sun time on water> and sun angle goes overhead.
100ft drop back or side planers are critical on shallow kokes, the OB sound drives them down especially with the huge tiger muskies in the res. that they're scared to death of, noisy predator.
You may be seeing the squawfish on the sonar, they school.
http://fishwithgary.com/kokaneeuniversity.html
The reservoir will flip warm/cold water shortly after the runoff, then the fish go deeper as the summer progresses searching for that perfect 54d F. their tiny nit brains are programmed for by 10 of thousands of years of evolution and spawning cycles to the 54d F ocean they love. Think sockeye
As the water warms and the lake flips temp column with sun angle and warm air temps, the feed and the koke 54d F depth range end up matching for awhile.
July Aug, their nit brain turns on to sex and reproduction, then the food and sex fight is really on. Got to grow into the biggest baddest koke for reproduction success. They will hit anything that is in their comfort competition zone.
By end of season in Sept in a hot year, the kokes are cooking in 55d F++ water in the very deepest holes with the most dam release current and the water column is thick with algae down to 50ft+
