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Systematic Mapping of Bedrock and Habitats along the Florida Reef Tract—Central Key Largo to Halfmoon Shoal (Gulf of Mexico)

USGS Professional Paper 1751

by Barbara H. Lidz, Christopher D. Reich, and Eugene A. Shinn

Introduction: Table of Contents Project Overview Project Objective Geologic Setting Primary Datasets Primary Products - Overview Maps & Evolution Overview: Introduction Depth to Pleistocene Bedrock Surface Reef & Sediment Thickness Benthic Ecosystems & Environments Sedimentary Grains in 1989 Summary Illustration Index Map Evolution Overview Tile-by-Tile Analysis Organization of Report Tiles: 1, 2, 3, 4, 5, 6, 7/8, 9/10, 11 Summary Acknowledg- ments References Disclaimer Related Publications

Tile 6 Geography Sector-Specific Studies Marine Sanctuaries, Marine Archaeology, and Looe Key Reef Marine Sanctuaries Marine Archaeology Looe Key Reef Geologic Highlights Marine Sanctuaries: The National Marine Sanctuary (NMS) Program of the National Oceanic and Atmospheric Administration (NOAA) has managed segments of the coral reef tract in the Florida Keys since 1975 (Causey, 2002). In 1975, the Key Largo NMS was established to protect 353 km2 of coral reef habitat extending from just north of Carysfort Reef Lighthouse to south of Molasses Reef (Fig. 86B). In 1981, an 18-km2 area at Looe Key Reef (parallelogram in Fig. 86C) was designated the Looe Key NMS to protect and promote the study, teaching, and wise use of resources at that specific reef. Mounting threats to the health and ecologic future of the entire coral reef ecosystem later prompted Congress to take action to protect fragile resources throughout the keys. Perceived and actual threats included potential oil drilling activities (e.g., Dustan et al., 1991), anchor damage from recreational boats (e.g., Halas, 1985), grounding of ocean-going vessels (e.g., Hudson and Diaz, 1988), disruption of bottom habitat by treasure salvors (such as east of East Turtle Shoal, see Benthic Ecosystems for Tile 4; Tucker, 1997), injection of sewage into 40,000 septic tanks, cesspits, and disposal wells (Shinn et al., 1994), and degradation of water quality (e.g., Hallock and Schlager, 1986; Hallock, 1988; Williams et al., 1997). Coral reefs, seagrass meadows, and mangrove communities were increasingly showing signs of stress. Many marine organisms use more than one habitat during their life stages, and deterioration within any one habitat would be detrimental to survival of those organisms. As a result, in 1990, Congress designated 9,600 km2 of the reef tract as the Florida Keys National Marine Sanctuary (FKNMS), incorporating numerous smaller state parks, reserves, and marine sanctuaries under a single umbrella (FKNMS boundary shown in Fig. 6A). The State of Florida has administered resources in nearshore waters for many years and continues to collaborate with NOAA now that those waters are part of the FKNMS. Sanctuary-wide regulations address large-scale direct and indirect impacts to coral reef resources by affording protection from oil-and-gas exploration, mining, large shipping traffic, and boat anchorage on shallow-water corals. In addition to these regulations, NOAA implemented more restrictive measures in 1997 by designation of 23 fully protected "no-take" zones, where lobstering, fishing, spear fishing, touching coral, and collecting shells, live or dead coral, and reef fish or "live rock" for the aquarium trade are prohibited. These 23 zones include 18 Sanctuary Preservation Areas (SPAs), four Research Only Areas (at Conch Reef, Tennessee Reef, Looe Key Reef, and Eastern Sambo), and one Ecological Reserve (at Western Sambo). Seven of the SPAs are located within two broader Existing Management Areas and include reefs at Carysfort, The Elbow, Key Largo Dry Rocks, Grecian Rocks, French, and Molasses Reefs off the upper Keys, and Looe Key Reef off the lower Keys. Addition of the two areas of the Tortugas Ecological Reserve in 2001 brought the current number of no-take zones to 24 and enlarged the Sanctuary to 9,844 km2 (Fig. 6B). Additional details about most of these sites can be found at http://www.floridakeys.noaa.gov/research_monitoring/map.html. continue to: Marine Archaeology

Coastal & Marine Geology Program > Center for Coastal & Watershed Studies > Professional Paper 1751