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GIS Compilation of Data Collected from the Pulley Ridge Deep Coral Reef Region OF 2005-1089
OF       2005-1089

Disc       Contents

Introduction

Surficial       Geology

GIS/Visualization

Data       Catalog

References       Cited

Acknowledgments

Contacts
Introduction:
Pulley Ridge is a chain of drowned barrier islands that extends almost       200 km in 60-90 m water depths (Fig. 1). This drowned ridge is located on the Florida       Platform in the southeastern Gulf of Mexico about 250 km west of Cape       Sable, Florida (Jarrett and others, 2005). These islands formed during the       early Holocene marine transgression approximately 12,000 - 14,000 years       before present, and were then submerged by sea level rise and preserved       near the outer edge of the Florida Platform. The southern portion of       Pulley Ridge is the focus of this study. This area hosts zooxanthellate       scleractinian corals, green, red and brown macro algae, and a mix of deep       and typically shallow-water tropical fishes. This largely photosynthetic       community is unique in that it thrives with less than 5% of the light       typically associated with shallow-water reefs with similar fauna.

Several factors help to account for the existence of this unique       deep-water community. First, the underlying drowned barrier islands       provide both elevated topography and lithified substrate for the       establishment of the hardbottom community. Second, the region is commonly       bathed by the Loop Current, which brings relatively clear and warm water       to this area. Third, the ridge's position on the continental shelf places       it within the thermocline which provides nutrients to the reef during       upwelling (Halley and others, 2003).

The USGS has made two       proposals to resource managers for the designation of marine protected       areas based on the geophysical and photographic data in this report. The       proposals describe areas that may require some regulatory protection of       marine life utilizing the sea floor (Fig. 1).

Figure 1 shows the study area and suggested areas             of regulatory protection.

The first proposal is that the area of greatest hermatypic coral cover       (Fig. 1) is considered for future management actions and       designated a Habitat Area of Particular Concern (HAPC) by the Gulf of       Mexico Fishery Management Council. HAPCs are identified on the basis of       habitat level considerations:
- The importance of the ecological function provided by the         habitat.
- The extent to which the habitat is sensitive to human-induced         environmental degradation.
- Whether and to what extent development activities are or will be         stressing the habitat.
- The rarity of the habitat type.

The second proposed area is for Coral Essential Fish Habitat (CEFH,       Fig. 1). CEFHs are defined as "those waters and substrate necessary to       corals for spawning, breeding, feeding, or growth to maturity." The       following definitions are provided for clarification:
- waters is defined as "aquatic areas and         their associated physical, chemical, and biological properties that are         used by corals"
- substrate means "sediment, hard bottom,         structures underlying the waters, and associated biological         communities"
- necessary means "the habitat required to         support a sustainable population and the managed species' contribution         to a healthy ecosystem"
- spawning,breeding, feeding, or growth to         maturity covers the full life cycle of a species. 

The CEFH shown in Figure 1 is the greatest coral cover in the region as       determined by the bottom photo and video transects acquired during this       study. 

This report presents the geophysical and photographic data that were       collected to describe the surficial and shallow subsurface geologic       framework of the area where these deep-water corals are known to occur.       The data types include multibeam bathymetry, sidescan-sonar imagery,       images of high-resolution seismic-reflection profiles, and bottom       photographs. In addition, the tracklines for the seismic data, locations       of bottom photographs and camera drifts, and tracklines along which       submersible and remotely operated vehicle (ROV) observations were made are       contained in the GIS files accompanying this report.       Unfortunately, video footage from the camera drifts, submersible, and ROV       cruises is not available on this DVD due to the quantity of data. The       bottom photograph data set has been previously published (Cross and       others, 2004), however it is included in this publication in an effort to       integrate the varying data sets in one location. This integration is       accomplished through the GIS data included on this   DVD.
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U.S. Department of the Interior | U.S. Geological SurveyURL:       woodshole.er.usgs.gov/pubs/of2005-1089/htmldocs/intro.htmPage Contact       Information: WHSC       WebmasterThis page last modified on Monday, 14-Jan-2013 12:50:16       EST