NMFS is designating critical habitat for Johnson's seagrass (Halophila johnsonii) pursuant to section 4 of the Endangered Species Act (ESA). Johnson's seagrass is found on the east coast of Florida from Sebastian Inlet to central Biscayne Bay. Within this range, 10 areas are being designated as critical habitat: a portion of the Indian River Lagoon, north of the Sebastian Inlet Channel; a portion of the Indian River Lagoon, south of the Sebastian Inlet Channel; a portion of the Indian River Lagoon near the Fort Pierce Inlet; a portion of the Indian River Lagoon, north of the St. Lucie Inlet; a portion of Hobe Sound; a site on the south side of Jupiter Inlet; a site in central Lake Worth Lagoon; a site in Lake Worth Lagoon, Boynton Beach; a site in Lake Wyman, Boca Raton; and a portion of Biscayne Bay. NMFS is modifying various aspects of the proposed rule, including the removal as critical habitat of the Intracoastal Waterway (ICW) channel in the designated areas, and enlarging the Lake Wyman site. The designation of critical habitat provides explicit notice to Federal agencies and the public that these areas and features are vital to the conservation of the species.