Researchers from the U.S. Geological Survey and the University of Hawaii assessing erosion along 150 miles of island coastline found an average loss of 0.4 feet per year from the early 1900s to 2000s, a university release said Monday.
The most extreme erosion -- nearly 6 feet per year -- was at Kualoa Point on East Oahu, they said.
The researchers used historical data sources such as maps and aerial photographs to measure shoreline change at more than 12,000 locations.
Erosion is the ultimate fate of all the Hawaiian Islands, researchers said.
"The inevitable fate of the Hawaiian Islands millions of years into the future is seen to the northwest in the spires of French Frigate Shoals and the remnants of other once-mighty islands, ancestors of today's Hawaii, but now sunken beneath the sea through the forces of waves, rivers, and the slow subsidence of the seafloor," USGS Director Marcia McNutt said.
However, researchers said, there are more immediate concerns over erosion rates.
"These data have allowed state and county agencies in Hawaii to account for shoreline change as early as possible in the planning and development process so that coastal communities and public infrastructure can be sited safely away from erosion hazards areas," William J. Aila Jr. of the state's Department of Land and Natural Resources said.
"This will vastly improve upon public safety and will ensure that Hawaii's beautiful beaches will be protected from inappropriate shoreline development."