California Code, Fish and Game Code - FGC § 8463

Traps not over 24 inches in greatest length nor more than 12 inches in greatest depth or width, or seines of not over 1/2 -inch mesh stretched measure and not more than 4 x 30 feet in size, may be used for the taking of fish of the carp and minnow family (family Cyprinidae), suckers (family Catostomidae), sculpins (family Cottidae), or mosquito fish (genus Gambusia). Such traps may be used only in lakes and impounded waters. Such seines may be used only in lakes, impounded waters, and conduits.

Fish taken as provided in this section may be sold only as bait. Fish other than those named in this section that may be taken in such traps or seines shall be released and returned unharmed to the water wherein taken.