One of the thoughts on this is that while the sampling numbers are way down what they can not account for is that the crabs are using a different migratory path. This could give a false flag as to a crash in the population. What changes could be food sources, water temperature, or habitat being different. Excessive harvesting does not fit a rapid decline of 80% loss of crabs. I am sure an answer will come forth and we can enjoy them again at the table.
Art