For some reason, Ohio (and specifically southwestern Ohio) holds a major concentration of paylakes, probably more per area than any other region of the US (at least for catfish). This is a booming business and the reason why the increase in commercial fishing is occuring. In just the past few years, a lot more paylakes have started up, and all the ones I know of stock lots of big flatheads and blues. 10 or 15 years ago, the size of a respectable flathead from a paylake was usually 20 or 25 pounds. You didn't see the 30's, 40's, 50's, etc. like you do today, and you never saw bluecats. Paylaking has followed the overall trend in increasing popularity of catfish, and people want more of a chance at catching the large fish. Because of this, the commercial fishing that occurs on the Ohio River is different from that which occurs most other places -- these fish aren't harvested as food sources like so many places in the South. They're transplanted from their natural habitat into these artificial ponds.
Now, I don't want this to sound like an attack on paylakes. I fished paylakes for a few years, which is why I know so much about what goes on there. They provide a service to a large group of people. The problem is what once had nothing more than a cult following has grown into a major business. The original idea of a paylake -- a place where someone can come to catch a few fish, usually for the table (trout, channel catfish, etc) has changed into a "trophy" fishery, where fishermen catch fish for money, and sometimes lots of $$, and this change in philosophy is what has created many of our problems here in Ohio.
The demand for large catfish is so great that many lakes have turned to other sources for their giant cats. As the sting operation that was released last year showed, many paylakes have resorted to buying fish illegaly from people who catch them from our local lakes and rivers, so now not only is the Ohio River affected, but all of our waterways are. Many lake owners have turned to commercial fishing from other states like Arkansas and Tennessee to supplement their stocks from the Ohio River. This is in part because they receive blue cats and larger flatheads from these waters, but also because it's getting more difficult to obtain all the fish they need from the Ohio River alone. I know a few people who commercial fish for paylakes, and they keep every catfish they catch, no matter what size. They stock their own lake with the choice fish, then sell the rest to surrounding lakes.
Just a little info. I wanted to post regarding the reasons for commercial fishing and why the problem is becoming more and more important.