Works for shrimp as well. On some of the bayous south of New Orleans, people will set up metal arms like the ones used to control entry into parking lots (though obviously larger) and attach shrimping nets to them. When the ebb tide begins, they lower the boom. When the flow velocity gets lower, they raise it and harvest what's inside. Most are not very large, but (unsurprisingly) they are home to a lot of fishing camps, and small shrimp make good bait for redfish or black drum (which, in addition to being fun to catch, are absolutely delicious).