MARSHALL ISLANDS. Giant clams three metres (10 feet) across have always been a special delicacy for the people of the Marshall Islands, but are increasingly rare. They are still found in the infrequently visited huge lagoons of uninhabited atolls often hundreds of miles from the nearest permanent settlements. Using seawater tanks the islanders have developed a method of farming them. Growing them to 500 millimetres (19.6 inches) across and selling to the for US$6 each, to be grown for the export market. 2004.