It is generally understood (not really scientific) that during the spawning runs the walleye are not usually feeding. When they are off the actual spawn area, they will feed, such as catching them on Lake Erie trolling this time of year around the reefs. In the real murky or muddy water, when actually in spawning or looking to spawn, they are most likely not in predation mode. In the rivers this time of year (spring) the water is almost always muddy or at best 5-8 inches of visibility. Usually it's less the 3-4 inches. Basically you have to drop the jig right in front of the fish in order to cause a "reactionary" strike. With so many fish in the river, thousands in any one stretch, it's not real hard to get a floating jig in front of a walleye's head (if you know what you are doing). In the "old" days before the use of the floating jig system, most river walleye were snagged with lead head jigs. Few were actually caught. The floating jigs enable the jig to be put in front of the walleye for a few seconds which can cause a strike, even in the real muddy water. On the Lake Erie reefs it's probably the same. When the water is all muddied up like it is now you'll have to drop that lead hair jig right in front of the walleye. When the water is clearer the fish can see the lure from a longer distance and you can get more strikes. Since the fish are usually not actively looking for prey, they probably don't pay much attention to their other senses that can detect prey, so most likely they will ignore a signal of potential prey that is out of sight.

This is all generally speaking, there are exceptions, so please no comments about how walleye do feed on the spawn. They do. Most likely it's just not their main focus.