Yep, with very little vegatation ground cover and typical spring rains, the tributaries of Lake Erie and Lake St. Clair (Thames, Maumee, Sandusky, and smaller ones) pump a lot on "muddy" water into Lake Erie (it's actually mostly very small clay particles from the clay-based soils of Ohio, southern Michigan, and southern Ontario). Thanks to the region's typical farming practices, clay/silt runnoff is very heavy. Maumee Bay and the nearer areas of Lake Erie are nothing like they used to be pre-1820's or so.

Yes, all the way up through most of June there is a thermocline (a transition line between water layers of different temperatures) in the Western Basin of Lake Erie. As the warmer and lighter river waters enter the colder and denser Lake waters, they displace and push over top of the colder, heavier Lake water. The farther you go from the river source, the more thermocline you'll find.

In early spring (iceout through April) the thermocline will vary from a few feet below the surface to about half way down to the bottom. In the reef areas and deeper areas off them the colder lower level water is often more clear than the upper (surface) layer, but not always, sometimes the opposite is true due to winds that create currents stirring up the bottom silt/clay.

As the season progresses, the thermocline moves both vertically (as the river waters push it eastward) and horizontially (as the water column warms up). I've personally seen numerous thermoclines scuba diving Lake Erie. At times they are pretty amazing, the transition from warm to cold being only a few inches, and I've seen clarity differences that look like there is a sheet of glass searating the two layers.

So yes, it happens that at times the fish are going to be in one layer or the other, but they may not be there for the reasons some fisherman think (because the water is clearer, or colder, or the presence of or lack of currents). The only way (other than years of experience) to really tell what's down there is to use a drop-over camera and check for clarity.

NOAA satilight (sp?) web site: http://coastwatch.glerl.noaa.gov/mod...egion=e&page=1

West Basin