Water surface temperatures finally dropped out of the 80's. This is the first sign of cooling and its long overdue as far as Lake Powell fish are concerned. Since the end of June the lake's surface has had an 80 degree lid covering an ever deepening layer of warm water. Warm water is lighter and floats on top of cold water. This process is called stratification. The long, hot summer has made the uniform warm water layer almost 60 feet thick. If bottom depth is less than 60 feet temperature is 77 F from top to bottom. The temperature drops quickly after that until it reaches the coldest range which is 46 degrees. That's the temperature of water released through the dam from the bottom of the lake
Some fish don't like the thick warm layer. Adult stripers simply can't live in water that warm. Swimming in the warm layer will kill big stripers after a short time. School-size 2-3 pound stripers tolerate the warmth but they need to dive to deeper water periodically to cool off. Little stripers and small bass like the warmth just fine and they have the run of the shallows this time of year.
Shad use the warm layer for protection from the bigger predators. They never get deeper than 35 feet in the summer making it difficult on large predators who must swim through at least 25 feet of hot water to find food. Shad compound the problem by moving well back in the canyon where lateral distance to cool water may be a half mile. Once isolated in this manner prey fish are separated from predators. When the journey gets too arduous the predators finally quit making the trip and just wait for cooling.
That is the fish mind set anglers are facing heading into the Labor Day weekend. Many fish have quit making the trip and are in deep cool water where metabolic rate is slower and waiting is more comfortable. Striper fishing is tough from Hite to Wahweap. Bait needs to be 45 to 60 feet deep to entice stripers. Adult smallmouth are less effected by warm water. They can move up and down at will but they are choosing to stay at 30-40 feet now. Stripers and larger bass are not very willing to participate in your holiday weekend fishing trip.
What can you catch? The overabundant population of 7-10 inch smallmouth is still shallow and still catchable on soft plastic grubs. Catfish really like warm shallow water and they are constantly prowling looking for food. They can be caught ant time. Bigger stripers can be taking on anchovies and spoons at 60-90 foot depths mid way back in major canyons that have shad in the shallow back end. When graphing today I found shad in most canyons in the lower lake, including Navajo, Warm Creek, Gunsight, Padre, Kane Creek and Kane Wash.
My only bright spot happened very early this morning. I saw fish jumping in Gunsight Bay as long as the water was shaded from the morning sun by Gunsight Butte. Surface lures cast to the scattered fish produced some nice 13 inch smallmouth bass. This can be duplicated in the evening just before or at dark. Larger bass come shallow to feed on shad at twilight. For best results go early and stay late. Expect fishing to get better when water temperature drops in to the low 70's.