The judge was correct in that instance--property rights in Mass extend to the mean low water mark, or to "100 rods" of the mean high water mark where the tidal range exceeds 100 rods. It's different in most other states, where property rights end at the mean high water mark. You cannot walk on the inter tidal zone. However, the public DOES have a right to walk in the intertidal zone, between high and low water, for three specific purposes--fishing, waterfowling and navigation. This has been the law in Mass since 1648 and this right of passage for these purposes has been consistently upheld by the Supreme Judicial Court, most recently in the mid 1970s in the case of Barry v Grella.
So, you can fish from Belushi's beach. You can shoot ducks from Belushi's beach, and you could probably portage your canoe or lead your skiff along it on a foggy night. But, you can't take a sunset stroll or collect shells there--unless the clams are still in the shells
