Anglers know that walleyes have unique eyes allowing them to see particularly well in low-light conditions. It’s no secret this same eyesight often causes walleyes to avoid bright-light conditions. This scenario creates a well-proven pattern of walleyes holding deeper in brighter light conditions, and shallower as light decreases.
This light intensity-location scenario is generally an ironclad rule for lake fishing, except early in the season when walleyes seem to buck this trend and hang shallower near spawning grounds. As much as light levels effect walleye location, there is a greater factor to consider for identifying walleye fishing locations, especially river walleyes.
Before I get too far, I want to quickly point out the well-known fact that wind drives walleye shallow. The more wind, the higher the waves, and the higher the waves, the less light penetration into the water which brings ol' marble eyes shallower. In essence, it is light diffraction that positions how deep walleye hold in lakes or rivers.
Wave action cuts light penetration, but "dirty" water is the greatest influence in stopping light penetration into water. This includes water either carrying a heavy sediment load, water high in suspended and dissolved particles, or water high in tannins. Each lake or river has differing water characteristics of suspended and dissolved particles and may have tannins as well.
With the exception of algae blooms, the level of these suspended and dissolved particles and tannins in lakes is usually relatively static. This means a lake’s water clarity changes more slowly over time, typically. With rivers, meanwhile, water clarity varies and differs over time thanks to their tributaries. When the snow pack melts, and April showers come, the creeks, streams, and small rivers contribute suspended sediment into the big river.
Changing River Conditions
River fishermen know water clarity is not static. They are aware it changes on a regular basis, from new inputs. This spring on the Mississippi the water has been very clear and because Minnesota’s cold March created little melt, the water actually is not much darker than it was in middle of winter. Last year during this same time, the water was far dirtier and higher.
To tangle with a true hog, your best bet is to fish shallow, but shallow does not work when the water is clear. To gauge fish-holding depths you need to have a handle on the how dark the water clarity is at the time. In dirty water, walleyes can and will hold in as little as two feet of water during the day.
Rivers flow in interesting ways. New inputs into a larger river are often dirtier than the main river. These inputs are usually smaller streams than the main river, and they create an eddy where they enter. These eddies circle into themselves and keep their dirtier water, and within these eddies the water clarity is darker than the main river. Here fish can be found shallower than the main river. However, this darker water in the eddy maybe too dark Indeed, reading water clarity and picking the best walleye holding depths for the time of day does take time.
Water clarity in rivers is not a situation where the dirtier the better, it is a situation where you want some, but not too much. It is like water flow, you want some, but too strong and the eyes will not hold there.
In general, for good daytime shallow water fishing you need to have some color in the water.
In spring huge water often rises make fishing very difficult, as the water is just too dirty, and fish have a difficult time picking up your bait. I have found the best fishing happens after the river crests and the ultra-dirty water clears.
Clarity not only effects fish-holding depths, but also determines the best times of day to target big fish.
Remember big fish in the shallows are feeding, so if the water is clear they will not move shallow until low-light conditions. When the water is very dark, the night bite is poor.
In extremely dirty water, the best fishing often takes place in the shallows during bright sunshine with no wind and no clouds. I have come to believe the additional light actually helps fish locate prey better in this incredibly dark water.
In lake or rivers, water clarity strongly affects walleyes’ depth. Get in touch with your river water clarity. Pay attention to how clear your river typically is and how conditions are affecting it. Develop a feel for water clarity and get ready to tangle with some of the biggest walleyes swimming.
Turk Gierke operates Croixsippi Guide Service; to book a trip, call (715) 377-0006, or visit www.croixsippi.com.