Walleyes can tolerate an exceptionally wide
range of environmental conditions from northern Canada to the southern United States. The
walleye is a cool water species, meaning that it prefers intermediate temperatures when
compared to warm water fish like bass and cold water fish like trout.
Walleyes prefer water of relatively low clarity. They are most abundant where
suspended silt or algae, or bog stain limits visibility to about 3 to 6 feet. Many people
feel that this is because they have light sensitive eyes, but I believe it is because they
have an advantage over baitfish in these conditions with their great low-visibility
eyesight. If walleyes are so sensitive to light, then how come I find them in the shallows
on calm days? I believe they just prefer the low-light areas to ambush their prey.
Differences in clarity within the same body of water may affect walleye
location. In a clear lake, researchers found that walleyes were 10 times more abundant in
the turbid zone near a river mouth than in other parts of the lake. However, they did not
mention at what time of year this was... maybe baitfish were spawning near the river
mouths at that time, which would cause walleyes to follow.
Walleyes generally select clean, hard bottoms rather than bottoms of silt,
muck or other soft materials. They favour bottoms with a combination of sand, gravel and
rock. This type of bottom produces a great deal of insects and other invertebrate
life which in turn attracts baitfish which then attracts walleyes. In fertile lakes, the
bottom is often covered with a thick layer of soft sediment. Experienced anglers know that
if they can find an exposed rock pile or gravel bar, it will usually hold walleyes.
Shallow, rocky shorelines and reefs make
ideal spawning grounds. The eggs fall into crvices between the rocks where they are safe
from crayfish and other egg-eating predators. Spawning is most successful in large lakes
because the spawning habitat is exposed to the wind. Some wave action is necessary to
prevent the eggs from silting over and keep them aerated. So it is not surprising that
lakes of this type have the highest number of walleyes populations. Walleyes also spawn in
their native rivers and streams if there is enough rocky bottom.
Walleyes
avoid water with dissolved oxygen content below 4 ppm (parts per million). But contrary to
popular belief, they do not seek out areas with higher oxygen levels. It is true that
windswept portions of the lake draw most walleyes, however, the fish are attracted by the
concentration of food that is swept into the area, not by higher oxygen. Walleyes can
tolerate oxygen levels as low as 1 ppm for short periods. It is not unusual for walleyes
to move into deep water with a low oxygen level, especially when there is an easy source
of food in the depths or water in the shallows becomes too warm.
Walleyes are native to most major river systems in the North, so they are
accustomed to live in current. Given a choice, lake-dwelling walleyes will seek areas of
light current rather than stay in slack water. The highest concentration of walleyes are
often found around inlet streams, in narrows separating two basins of a lake or in areas
with wind-induced currents.
Habitat