Bathymetry and Selected Views of the Fringing Coral Reef, South Moloka'i, Hawaii

U.S. Geological Survey

The fringing coral reef along the south side of the island of Molokai is one of the most extensive fringing coral reefs in the Hawaiian chain, if not in the entire Pacific. For a distance of about 40 kilometers (25 miles), from Hale o Lono on the west to Kamalo on the east, live coral coverage is estimated to be 60 percent to 90 percent higher than all but the most shielded reefs in Hawaii.

The reef is actively accreting in depths between about 6 and 27 meters (20 and 90 feet), creating, as these views show, spurs, grooves, knobs, pits, and pinnacles that are home to thousands of marine organisms. Winter waves restrict active reef accretion beyond the sheltered portion of the coast but the old reef surface in those areas is still populated by numerous individual coral colonies, invertebrates, and fish.

These images of the coral reef were created using high-resolution bathymetric data collected in 1999 and 2000 by the SHOALS (Scanning Hydrographic Operational Airborne Lidar Survey) airborne laser imaging system operated by the U.S. Army Corps of Engineers. The system collected over 12 million depth measurements during the Moloka'i surveys, with a vertical accuracy of 15 cm.

Courtesy of U.S. Geological Survey.

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