In the past, the State had the authority (from Boldt, actually) to manage for conservation. They could and did shut down tribal fisheries when total harvestable had been taken and when they had taken their share if their fishery would catch non-Indian allocation. For example, say the tribe's had taken their chum allocation and the non-Indians hadn't but there was no way for the NI net fishery to access them, then they would be allowed to fish "into" the NI share (NI sport had already been accounted for).

Unfortunately, the state tried to close the Quinaults at 9AM and the tribe closed at noon. State went out and arrested/cited fishermen. Obviously, this went to court and the judge ruled that the tribes had to agree to the closure.

After co-mnagement started in full force, each side was responsible for managing its own fleet. The state gave up the conservation responsibility. A few years later the state almost grew a pair sufficient to issue a closure but backed down when the tribes said they would close. And didn't.

Short answer is the state could do something for conservation but won't. And there are others here aware of situations where the state will close a rec fishery with harvest remaining because the tribe will fish if the recs do regardless of share status.