[SUPERTROLLER]

I've come to find that most of the time when I'm marking lots and lots of fish and not catching many of them, that these are the walleye. When I'm marking good numbers and catching sheephead, catfish, carp, and perch; I'm usually over a lot of sheephead, catfish, carp, and perch.

There are really only 2 things you can do.
1) Catch whatever is under the boat to see what it is you're marking.
2) Drop a camera down to see what under your boat.

There is no way to differentiate between individual fish on your graph. You CAN tell when a school of baitfish is under your boat but not necessarily whether they are shad or alewives or shiners or smelt.