The answers vary greatly from state to state. State fishery management plans can be hard to find online. I've started putting together links to blue crab stock assessments and fishery management plans on my website. I'm working on finding links to management plans for each state in which blue crabs are caught commercially, but some are either difficult to find or are not available on the web. Pat Geer of the Coastal Resources Division of Georgia Department of Natural Resources was very helpful in responding quickly to a request to post the Georgia blue crab management plan.
If you find links to other state or regional plans, send them my way and I'll add a link.