There are a lot of regulations for the commercial fisherman, including the trap nets, especially once the recreational boating season starts. Too many to go into here, but yes, they often set trap nets close to shore to catch various species including perch. Part of reason is the somewhat limited areas they can legally fish, plus who would want to put an expensive net out where you legally can but have it susceptible to boaters that have no idea what it is or are even looking out for nets. I've been in the Port Clinton Fish company and seen the catfish in bins they had caught that day.