Partners in a plan to restore 125 acres of degraded coastal wetlands as a mitigation project for the Carlsbad seawater desalination plant celebrated the start of construction Friday morning in Imperial Beach.

The Otay River Estuary Restoration Project in South San Diego Bay is a joint effort by the desalination plant operator Poseidon Resources, the U.S. Fish and Wildlife Service and other agencies to improve the habitat for native fish, plants and birds, particularly migratory shorebirds and other salt marsh-dependent species.