California Code, Fish and Game Code - FGC § 7850

(a) Excepting persons expressly exempted under this code, no person shall use or operate, or assist in using or operating, any boat, aircraft, net, trap, line, or other appliance to take fish or amphibia for commercial purposes, and no person shall cause to be brought ashore, any fish or amphibia at any point in the state for the purpose of selling them in a fresh state or shall contribute materially to the activities on board the commercial fishing vessel, unless the person holds a commercial fishing license issued by the department.

(b) Any person not required under subdivision (a) to hold a commercial fishing license shall register their presence on board the commercial fishing vessel in a log maintained by the owner or operator of the vessel according to the requirements of the department.

(c) As used in this section, “person” means a natural person 16 years of age or greater.  Any person, partnership, corporation, limited liability company, or association may pay the fees for a license issued to any person.

(d) This article does not apply to the taking, transporting, or selling of live freshwater fish for bait by the holder of a live freshwater bait fish license issued pursuant to Section 8460.