It is illegal to import, transport, or possess live Chinese mitten crabs (Title 14, Section 671 of the California Code of Regulations). Accidental release or escape will spread these crabs to uninfested waters. If you keep a mitten crab, it must be dead. You must posses a valid California Sport Fishing License to fish for Mitten Crabs. Upstream of the Carquinez Bridge, you can only fish by hook and line and there are no bag or size limits. Downstream of the Carquinez bridge, you can fish with traps and hook and line, but the limit is 35 per day.