The study was the first time that satellite-derived shorelines were used for this sort of analysis and the results are alarming. Point Arena and Humboldt Bay in northern California, Pismo Beach and Morro Bay in central California, and Newport Beach and San Clemente in southern California are all at particular risk from erosion.

"Beaches are natural resources," said Sean Vitousek, the researcher who led the study, "and efforts must increase to preserve them."

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