First of all no treble hooks (sonars) are allowed on the Maumee or any night fishing. There are some very strict rules in place on the Maumee for gear use and fishing times ,but I'm sure foul hooking and snagging goes on with that many fishermen , but it's also policed very strong. I fished it one weekend years ago and it's very crowded in the better spots. Not my kind of river being that muddy all the time, but it's a long huge shallow faster flowing river. 99% of all fishermen there are using floating single hooked jigs with a twister tail on back. Not a Pymy spillway snaggers choice for sure !
I highly doubt that 99% of Spillway Walleye are legally caught. Having never fished it, but standing and watching those that were one day convinced me real fast that after sundown it's a snag fest. You can judge most fishermen real fast by the gear they wear and use, and how they fish. One look at that shoulder to shoulder shore crowd ripping away on those Walmart rods convinced me I would never fish in that zone.. ever !