Why Is It So Hard to Find Local Fish (Even by the Water)?

On a cold, windy February morning on Shinnecock Bay, on the South Fork of Long Island, N.Y., Ricky Sea Smoke fished for clams from the back of his 24-foot boat. The fisherman, whose real name is Rick Stevens, expertly sorted through haul after haul as they were dumped onto the sorting rack.Among the usual littlenecks and cherrystones were delicacies that would make chefs swoon: sweet, plump razor clams; vermilion-fleshed blood clams; and dainty limpets (also known as slipper snails) with their inimitable saline, buttery flavor. Depending on the season, fishers like Mr. Stevens can bring in…