Each year, after crabs molt, there is a time when their shells are soft, and are not filled up with crab meat. This soft-shelled state is undesirable for fishers. Since the timing of molting varies from year to year, it is difficult for fishery managers to set the start date for the commercial crab fishing season. This four-year study in the early 1960s attempts to increase the information available to managers making this difficult decision.