right from the ODNR FAQ


Can I release a smaller fish to replace it with a bigger one to stay within my limit?

You can release smaller fish for bigger fish to stay within your limit. This is called “culling.” The released fish must be alive. If a person releases a dead fish to replace with a live fish of the same species to stay within their bag limit, both of the fish, live and dead, are counted and that person could then be charged with exceeding the daily bag limit for those fish. Also note that it is illegal to give any of your fish to anyone else to contribute to their limit.