(1) Except as provided in subsection (3) of this section, it is unlawful for a person who is not a treaty Indian fisher to participate in the taking of fish or shellfish in a treaty Indian fishery, or to be on board a vessel, or associated equipment, operating in a treaty Indian fishery. A violation of this subsection is a gross misdemeanor.

(2) A person who violates subsection (1) of this section with the intent of acting for commercial purposes, including any sale of catch, control of catch, profit from catch, or payment for fishing assistance, is guilty of a class C felony. Upon conviction, the department shall order revocation of any license and a one-year suspension of all commercial fishing privileges requiring a license under chapter 77.65 or 77.70 RCW.

(3)(a) The spouse, forebears, siblings, children, and grandchildren of a treaty Indian fisher may assist the fisher in exercising treaty Indian fishing rights when the treaty Indian fisher is present at the fishing site.

(b) Other treaty Indian fishers with off-reservation treaty fishing rights in the same usual and accustomed places, whether or not the fishers are members of the same tribe or another treaty tribe, may assist a treaty Indian fisher in exercising treaty Indian fishing rights when the treaty Indian fisher is present at the fishing site.

(c) Biologists approved by the department may be on board a vessel operating in a treaty Indian fishery.

(4) For the purposes of this section:

(a) "Treaty Indian fisher" means a person who may exercise treaty Indian fishing rights as determined under United States v. Washington, 384 F. Supp. 312 (W.D. Wash. 1974), or Sohappy v. Smith, 302 F. Supp. 899 (D. Oregon 1969), and post-trial orders of those courts;

(b) "Treaty Indian fishery" means a fishery open to only treaty Indian fishers by tribal or federal regulation;

(c) "To participate" and its derivatives mean an effort to operate a vessel or fishing equipment, provide immediate supervision in the operation of a vessel or fishing equipment, or otherwise assist in the fishing operation, to claim possession of a share of the catch, or to represent that the catch was lawfully taken in an Indian fishery.

(5) A violation of this section constitutes illegal fishing and is subject to the suspensions provided for commercial fishing violations.