Kevin, I looked all over the Kentucky Dept. of Fish & Wildlife resources website, 2008 Kentucky Fishing and Boating Guide , and I could not find any mention of Cast Nets AND the Ohio River.. Here's the only thing I could find in the KDFW Fishing Regulations :
Sport Cast Nets: Maximum sport cast net size is 20 feet in diameter with maximum 1-inch bar mesh statewide except in the following waters. Sport cast nets prohibited in: 1) lakes having fewer than 500 surface acres, 2) any of the streams and tailwaters listed in the Trout Waters section of this guide, 3) tributaries of the Cumberland River
between Wolf Creek Dam and the Tennessee state line except Crocus and Marrowbone creeks where sport cast mesh size must be made of 1-inch bar mesh only, 4) from the mouth of Crocus Creek upstream for 50 yards. All sport fish incidentally taken
while capturing live bait with seines, dip nets or cast nets must be released immediately
and unharmed into the water. You might want to call the KDFW INFO LINE: 1-800-858-1549
Good Luck Kevin
Frank