La. Stat. tit. 56 § 334.2
The saltwater angling license required in R.S. 56:302.1(C) shall not preclude a person from fishing for freshwater species of fish south of the designated saltwater line described in R.S. 56:322(A) or in saltwater lakes and bodies of water designated in R.S. 56:322(B). A person may take or possess in such designated saltwater areas, without a saltwater angling license, any freshwater species of fish in any number not otherwise prohibited by law, provided the person possesses a valid fishing license as otherwise required by law. For the purpose of enforcement, the department shall determine by rule which species of fish shall be classified as a freshwater species and which shall be classified as a saltwater species. Any person, without a valid saltwater angling license, that takes a saltwater species of fish as classified by the department from a designated saltwater area shall return such fish immediately to the waters from which taken without avoidable injury. An enforcement agent or officer of the department may inspect a fisherman's catch to insure compliance with this Section.
La. R.S. § 56:334.2