I believe it was several factors to include ESA but as I recall there was a big Departmental hue and cry about the cost to produce each of those resident blackmouth that was harvested. A cynic might suggest that the decision was made and then the bean counters went to work to justify it.

What they didn't look at (and that same cynic would say purposely) was the value of that fishery per fish harvested.

Another factor was the increasing number of pinniped predators eating those sub-legal blackmouth calling Puget Sound home.