California Code, Fish and Game Code - FGC § 7704

(a) It is unlawful to cause or permit deterioration or waste of a fish taken in the waters of this state, or brought into this state, or to take, receive, or agree to receive more fish than can be used without deterioration, waste, or spoilage.

(b) Except as permitted by this code, it is unlawful to use a fish, except fish offal, in a reduction plant or by a reduction process.

(c) Except as permitted by this code or by regulation of the commission, it is unlawful to sell, purchase, deliver for a commercial purpose, or possess on a commercial fishing vessel registered pursuant to Section 7881, a shark fin or tail or part of a shark fin or tail that has been removed from the carcass. However, a thresher shark fin or tail that has been removed from the carcass and whose original shape remains unaltered may be possessed on a registered commercial fishing vessel if the carcass corresponding to the fin or tail is also possessed.