Hawaiian Trough the Hawaiian Arch. The Hawaiian Arch extends about 200 meters above the surrounding ocean floor, and contains tilted coral reefs. The coral reefs in the Hawaiian Tough are described as mesophotic coral ecosystems, which can be found between 100 and 500 feet below sea level. 43 percent of fish species documented at the mesophotic reefs are unique to the Hawaiian Islands. At Maui’s ‘Au’au channel the largest uninterrupted mesophotic coral ecosystem was discovered, with an area larger than 3 square miles. These reefs contained many stony, reef building coral that belong to the genus Leptoseris, which are adapted for deep
Hawaiian Islands the United States. The eight main islands of Hawaii (also called the Hawaiian Windward Islands) are listed here. All except Kahoolawe are inhabited. Smaller islands, atolls, and reefs (all west of Niihau are uninhabited) form the Northwestern Hawaiian Islands, or Hawaiian Leeward Islands: The state of Hawaii counts 137 "islands" in the Hawaiian chain. This number includes all minor islands and islets, or very small islands, offshore of the main islands (listed above) and individual islets in each atoll. These are just a few: This chain of islands, or archipelago, developed as the Pacific Plate moved slowly northwestward over a