It shall be unlawful for any commercial crabber to catch or take, or attempt to catch or take, for commercial purposes any hard-shell, soft-shell or peeler crabs from any waters of the rivers and bays of this State and the tributaries thereof or sell, offer for sale or buy any hard-shell crabs taken from said waters, except the Delaware Bay and the Delaware River and that area of Roy's Creek which lies south of Fenwick Island Ditch.