It was like D-Day in coastal North Carolina. The state's ocean waters were tainted with tiny organisms of a subtropical species of red tide dinoflagellate that turns the water red. It leaves beachcombers coughing, fish suffocating, and shellfishermen out of work. The organisms have neurotoxins that affect the nervous systems of other organisms. Although it is safe to eat the fish, crabs, and shrimp that lie in red tides because it does not taint their flesh, oysters, clams, and scallops are another story.