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U.S. Geological Survey Open-File Report 2008-1351

USGS Cold-Water Coral Geographic Database—Gulf of Mexico and Western North Atlantic Ocean, Version 1.0

Introduction and Purpose

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Click on figures for larger images.
Thumbnail image of Figure 1, six examples of deep-water coral habitats, and link to larger figure.

Figure 1. Examples of the diversity of cold-water corals, shown in their natural habitats.

(A) Scleractinians and octocorals forming a bioherm on basaltic pillow lavas;

(B) Closeup of the polyps of the scleractinian Lophelia pertusa; (Photos A and B were taken on the New England Seamounts in the North Atlantic Ocean by the Institute for Exploration’s remotely operated vehicle (ROV), Hercules, and are provided courtesy of the Deep Atlantic Stepping Stones 2005 project (DASS05).

(C) Stylasterids (white and pink) and black solitary cup corals (Cladopsammia sp.) on carbonate rock;

(D) Close-up of a solitary scleractinian Cladopsammia sp.;

(E) Red octocoral and white Lophelia pertusa on carbonate rock;

(F) Carbonate pinnacle covered by octocorals and solitary scleractinians. 

(Photos C, D, E, and F were taken in the Madison Swanson Reserve in the northeastern Gulf of Mexico by an ROV operated by Lance Horn (NOAA/NURP) during a cruise of the R/V Liberty Star in 2005 (Scanlon, unpublished data).


The sidebar on each page of this report provides links to the major sections of the report.  The heart of the publication is the geographic database application which can be downloaded from the Download and Use the Database page.  This section of the report also contains detailed instructions for using the database and examples of typical searches and results.  The Methods section explains how the data in the database were compiled and explains the assumptions and limitations inherent in the taxonomic and positional data.  The Discussion section points out some of the ways the database can be used and cautions the user about pitfalls in using and interpreting the data. 

Four appendices provide some of the information that is in the database in convenient forms for users to access without downloading the database.  Appendix 1 is a list of the sources used to populate the database. Appendix 2 provides most of the data exported from the database in several file formats.  To use the map functions, search features, and to view photographs, however, the database application must be downloaded from Download and Use the DatabaseAppendix 3 contains 25 printable maps exported from the database, showing the locations of entries for each taxonomic family.  Appendix 4 contains tables listing all of the species represented in the database along with the common names, taxonomic authorities, and the number of records in the database.

About Cold-Water Corals

Cold-water corals (also known as deep-water or azooxanthellate corals) are found throughout the world’s oceans at water depths of just a few meters to over 6000 m. Although their existence has been known for hundreds of years (for example, Pontoppidan, 1755; Wilson, 2001), the abundance, species richness, and ecological importance of these corals have only recently been recognized. Cold-water corals are similar to the better known tropical corals, but thrive in cold and often dark water because they do not depend on photosynthetic symbiotic algae (zooxanthellae) to provide essential energy as tropical corals do.  Instead, these corals survive solely on food particles in the water column and on smaller pelagic organisms that come within reach of their tentacles.  As a result, cold-water corals are typically found in habitats with high particle flux, nutrient upwelling, strong currents, and hard substrate to which they can attach; however, our knowledge of the environmental constraints on individual species is sparse at best.

Cold-water corals (Fig. 1) exhibit a wide range of morphologies and inhabit a variety of seafloor habitats, but all corals have some form of carbonate skeleton composed of either aragonite or calcite (or sometimes both).  The term “coral” is a vague term and encompasses animals in several taxonomic orders.  All of the species commonly known as corals fall within the phylum Cnidaria and mostly within the class Anthozoa.  The corals in the class Anthozoa fall into one of three subclasses: Hexacorallia, Octocorallia, and Ceriantipatharia.  Hexacorallia includes the corals of the order Scleractinia (true or stony corals) which may have a delicate to massive aragonite exoskeleton (Brusca and Brusca, 2003).  Octocorallia includes the orders Alcyonacea (soft corals), Gorgonacea (sea fans and sea whips), Helioporacea (blue corals), and Pennatulacea (sea pens).  Ceriantipatharia includes the Antipatharia (black or thorny corals).  The orders that are important to this database can be summarized as follows:

Phylum Cnidaria
            Class Hydrozoa
                        Subclass Hydroidolina
                                    Order Anthoathecatae (for example, stylasterids)
           Class Anthozoa
                       Subclass Hexacorallia
                                   Order Scleractinia (for example, true or stony corals)
                       Subclass Ceriantipatharia
                                   Order Antipatharia (for example, black or thorny corals)
                       Subclass Octocorallia
                                   Order Alcyonacea (for example, soft corals)
                                   Order Gorgonacea (for example, sea fans and sea whips)
                                   Order Helioporacea (for example, blue coral)
                                   Order Pennatulacea (for example, sea pens)

Scleractinians and octocorals make up the majority of cold-water coral species, with stylasterids and antipatharians making up a smaller proportion.  Scleractinians can be solitary (single polyps living alone or in aggregations) or reef-building, and octocorals can form dense assemblages. All of these morphological types can provide important habitat frameworks for other species. Many species of cold-water corals are structure-forming, and so can literally build habitats, in some cases forming reefs many kilometers long.  Cold-water scleractinian reefs are known to support over 1,300 species of associated fauna (Atlantic Coral Ecosystem Study (ACES), 2003).  These biodiverse ecosystems can occur in most ocean provinces, including continental shelves and slopes, midocean ridges, and seamounts (Rogers, 1999; ACES, 2003; Roberts and others, 2006). Cold-water corals can also provide high-resolution paleoclimate archives in their aragonitic skeletons, allowing fine-scale detection of past climate events (Adkins and others, 1998). Even as knowledge of these corals expands, much of their habitat is being threatened by bottom trawling, mining, oil drilling, and climate change (Roberts and others, 2006). Understanding the distribution of cold-water corals is a critical first step for management decisions and research planning.

Purpose of the USGS CoWCoG Database

This Cold-Water Coral Geographic (CoWCoG) Database was developed between 2003 and 2010 at the USGS with partial support from NOAA (National Oceanographic and Atmospheric Administration). Coral locations in the Gulf of Mexico and the western North Atlantic Ocean were compiled from published scientific papers, government reports, museum collections, and other databases.  These sources date from the late 1800’s to 2008.  This database provides an accurate and extensive record of the locations of cold-water corals with an interface that will allow it to be used effectively by resource managers, scientists, environmental advocates, fishermen, and other users of the sea.

An important aspect of this database is the inclusion of extensive supporting information and references with each data entry. In addition to locations, taxonomic classification, and references, this database includes information about sample collection methods, the scientists and ships involved, navigational accuracy, and other details.  It was essential to create a database that is usable, contains as many listings as possible, and preserves the integrity of the data.

This database is easy to search and data can be quickly displayed in table form and on a map by using Microsoft Access 2000 or later and the software included with this publication.  Subsets of the database can be selected on the basis of geographic location, taxonomy, or other criteria and exported as a Microsoft Access database, Comma Separated Values (.cvs) file, an Environmental Systems Research Institute (ESRI) Shapefile (.shp), a Microsoft Office spreadsheet (.xls), or a dBase IV (.dbf) file, making it easy for users to incorporate output from this database into other datasets.  Users may also import their own .shp file for display in the CoWCoG Database.

Because this database is designed to be flexible and easy to use and the data have been carefully screened, it will provide a valuable tool for researchers and managers interested in studying, protecting, and/or utilizing cold-water coral habitats in the Gulf of Mexico and western North Atlantic Ocean.

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