California Code, Fish and Game Code - FGC § 7145

(b)(1) This section does not apply to an owner of privately owned real property, or the owner's invitee, who, without providing compensation, takes fish for purposes other than profit from a lake or pond that is wholly enclosed by that owner's real property and that is located offstream and does not at any time derive water from, or supply water to, any permanent or intermittent artificial or natural lake, pond, stream, wash, canal, river, creek, waterway, aqueduct, or similar water conveyance system of the state.Access and control of the real property shall be under the direct authority of the owner and not that of another person or entity.

(2) This subdivision does not, and shall not be construed to, authorize the introduction, migration, stocking, or transfer of aquatic species, prohibited species, or any other nonnative or exotic species into state waters or waterways. This subdivision does not supersede or otherwise affect any provision of law that governs aquaculture, including, but not limited to, the operation of trout farms, or any activity that is an adjunct to or a feature of, or that is operated in conjunction with, any other enterprise operated for a fee, including, but not limited to, private parks or private recreation areas.