Mich. Comp. Laws § 324.47328
A person shall not use any kind of a boat, tug, or launch, except when used in hook and line fishing, or any kind of net or nets, set hook lines, or commercial trolling rigs for the purpose of taking, catching, killing, or transporting fish in any of the waters bordering on this state, regardless of whether for commercial purposes or for personal use, without first having applied for and been issued a license for that activity, in accordance with this part. A license, except as otherwise provided by law, is not required of persons engaged in sport trolling in these waters, except that the owners of boats operated with either an inboard or outboard motor and offered for hire in sport trolling for lake trout shall obtain a license for each boat. A license, except as otherwise provided by law, is not required of persons engaged in taking fish with set lines in lake St. Clair as provided in section 47302.
MCL 324.47328