From the WDFW website:"Fishery managers rely on catch information provided by fishers to manage the Puget Sound Dungeness crab fishery and plan future seasons. Just as fishery managers rely on fish tickets to track commercial harvest, they depend on CRCs to estimate recreational crab catch. CRCs are also used to account for recreational harvest of other species such as steelhead, salmon, sturgeon, and halibut."

While other methods are certainly used, I suspect that CRC's are still the primary basis for estimation of crab, salmon and steelhead. Certainly the in-sample returns of salmon CRCs is still very important to sport catch estimation, and if voluntary returns of crab CRCs were not important to estimating that catch, why would you be fined $10 for not turning in your card? Creel checks which certainly are used in some places are notoriously expensive when asked to provide precise estimates, and those too, rely on voluntary, accurate reporting of catch to the census takers. Numerous posters on this board have even stated that in recent quota fisheries for Chinook in northern Puget Sound they routinely report no encounters with Chinook to the creel people to attempt to keep fisheries open longer. The point I'm trying to make is that both treaty and non-treaty catch estimation relies on voluntary information provided by fishers. Make whatever you want out of that fact.