Benthic habitat map for moderate-depth areas (30-60 m) south of St. John in the U.S. Virgin Islands.

Benthic habitats of the moderate-depth marine environment in and around the Virgin Islands Coral Reef National Monument of St. John were mapped using a combination of semi-automated classification and visual interpretation of acoustic imagery. This work replaces previous NOAA maps by Kendall et al. (2001) (1) for the waters around St. John. The objective of this effort, conducted by NOAA's Center for Coastal Monitoring and Assessment - Biogeography Branch in partnership with the U.S. National Park Service (NPS), was to provide spatially-explicit information on the habitat types, biological cover and live coral cover of the moderate-depth area south of St. John. This product provides a fine-scale assessment of the status, abundance, and distribution of moderate-depth marine habitats south of St. John. The NOAA effort provides the U.S. National Park Service with increased technical capacity for ocean exploration, management, and stewardship. Direct implications to management measures include evaluation of management efficacy, a spatial framework for improved monitoring sampling design, improved assessment of human-use impacts, and marine spatial planning to support alternative marine protected area boundary alternatives. Rhodoliths (encrusting marine red algae that resemble coral) and sand were the most common found habitats in the moderate depth region south of St. John. Turf, fleshy, coralline, or filamentous algae were pervasive in both the shallow and moderate depth areas, accounting for 74 percent and 92.8 percent of these mapped areas, respectively. Only four percent of the moderate depth area had live hard and soft coral covers greater than 10 percent. The moderate-depth map begins at the optical limit of the associated shallow-water benthic habitat map (GUI:VI004004), also poduced by NOAA for the region, and continues to the edge of the acoustic imagery. The integration of these two maps is possible, given that the same general habitat classification schemes and minimum mapping units were applied to both the shallow-water and moderate-depth maps. That being said, NOAA emphasizes that the differences between the two maps must be thoroughly understood, in order to recognize the limitations associated with using the maps in an integrated fashion. Integration of the shallow-water and moderate-depth maps will provide a seamless benthic habitat map, extending from the shoreline of St. John southward to the 55 m isobath. Both maps are found at https://coastalscience.noaa.gov/project/benthic-habitat-mapping-st-john-u-s-virgin-islands-national-park-reef-national-monument/.(1) Kendall, M.S., C.R. Kruer, K.R. Buja, J.D. Christensen, M. Finkbeiner, R.A. Warner and M.E. Monaco. 2001. Methods Used to Map the Benthic Habitats of Puerto Rico and the U.S. Virgin Islands. NOAA Technical Memorandum NOS NCCOS CCMA 152. Silver Spring, MD