I would agree with Jake. Too many crab are being harvested. It may be that paradigm of killing all the big males doesn't work, it may be that there are ecological changes that have altered productivity but at the end of the day more crabs are being killed than the population can sustain.

Constants aren't, variables won't and the environment is not consistenly productive at a fixed level. Harvesting at a fixed level is a recipe for disaster. Autopilot needs to replaced by hands-on pilots.