So I am posting this as a bit of clarification about crayfish harvesting at this time.
http://wdfw.wa.gov/publications/01500/wdfw01500.pdf
Pg 8 of 138 states: "You do not need a license if you are fishing for common carp,
crawfish, bullfrogs, smelt or to collect relic shells"
Here is where the clarification comes in, regarding native and invasive species.
http://wdfw.wa.gov/fishing/shellfish/statewide_rules.html
NATIVE SPECIES - "Min. size 3¼" from tip of rostrum (nose) to tip of tail. Daily limit 10 lbs in shell. All females with eggs or young attached must be immediately returned to the water unharmed. No Shellfish/Seaweed license is required. See Statewide gear rules."
NONNATIVE SPECIES - "Must be kept in a separate container.
Must be dead before being removed from riparian area (immediate vicinity of water body).
No daily limit, size, or sex restrictions. No Shellfish/Seaweed license is required. See Statewide gear rules."
"There is only one native crayfish species in Washington – the signal crayfish (Pacifastacus leniusculus). This species can be identified by its uniform brownish coloration, white or light coloration of the claw joint ,and the smooth surface of its carapace and claws compared to that of nonnative species.
Native crayfish are the
only crayfish that may be removed from the vicinity of the waterbody alive. If you cannot positively identify your catch as a nonnative species, the daily limit and other restrictions listed above for native crayfish apply."
Hope this clarifies the legality of harvesting crayfish.