That's pretty dangerous, since the bottoms are filled with concrete to keep them submerged. Perhaps they removed it.
Interesting tidbit on Lobster traps. I've been working for a plastering company. The boss tells me that back in the day when they wrecked out plastered walls that had wooden lathe as the substructure, they would salvage the wooden lathe. When they got a trailer load, they would haul it down to the Keys and sell it to the lobster trap makers. The old lathe had been saturated with lime for so long that it would last a lot longer in the saltwater than any new wood.