A fixed fish trap. The curtain nets stretch from surface to bottom, and the fish are funneled into holding areas.
Fish traps are only practical in shallow water. They have the advantage of keeping both the targeted catch and the bycatch alive ( unless a shark gets in ! ) You can still see a few fish traps in use in Raritan Bay, where they are built around fixed pilings rather than buoys and anchors as shown here. In years past, shore-based trawling or "haul seining" was also practiced in the bay, where a net would be deployed off the beach by a small boat, and drawn in by donkeys or trucks.