Northwestern Gulf Banks

Black and white contour map of the continental shelf off of Texas and Louisiana with named reefs and banks identified
Reefs and banks of the northwestern Gulf of Mexico

The region in which Flower Garden Banks National Marine Sanctuary resides is commonly known as the northwestern Gulf of Mexico. East Flower Garden, West Flower Garden and Stetson Banks are only three among dozens of banks scattered along the continental shelf in this region.

The first comprehensive descriptions of these reefs and banks was published by Texas A&M University researchers, Drs. Tom Bright, Richard Rezak, David McGrail, and others, as part of a project funded by the U.S. Department of Interior.

Researchers on the deck of a ship in the Gulf of Mexico in 1972
Researchers on a 1972 FGORC expedition to the Flower Garden Banks (Image Courtesy of Rusty Putt)

These explorations in the 1970s and 1980s were conducted in response to increased pressures by the oil and gas industry. The findings from these explorations were presented in a book entitled Reefs and Banks of the Gulf of Mexico, published in 1985. In this book, the authors presented the initial zonation scheme for deepwater habitats in the northwestern Gulf of Mexico.

Since 1998, the sanctuary research team has put considerable effort and resources into increasing our knowledge of these reefs and banks. With the help of many partners, they have obtained high-resolution multibeam bathymetry, then groundtruthed the areas to characterize the habitats of key features in the region.

Researchers on the deck of a ship in the Gulf of Mexico in 1972
Multibeam map of the northwestern Gulf banks with current sanctuary boundaries marked

Habitat Protection

Only East Flower Garden, West Flower Garden and Stetson Banks are currently under the protection of the National Marine Sanctuaries program. However, other banks do have some level of protection through the Bureau of Ocean Energy Management (BOEM) and NOAA Fisheries.

BOEM regulates the oil and gas industry in regards to their interaction with the reefs and banks through Topographic Features Stipulations which establish No Activity Zones at the topographic features.

Map of northwestern Gulf of Mexico showing HAPCs, Coral HAPCs, No Activity Zones (NAZ), NAZ Buffer Zones, and sanctuary boundaries

Several of the reefs and banks in the region have also been designated as Habitat Areas of Particular Concern (HAPCs) through NOAA Fisheries Essential Fish Habitat (EFH) legislation, which only applies to fishing vessels. Although this HAPC designation on its own does not carry any protective measures, it identifies the site as an area for special consideration during individual species assessments. 

An area may be designated as an HAPC due to:

  • 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 type.
  • The rarity of the habitat type.
Map showing Habitat Areas of Particular Concern (HAPCs) in the western portion of the northwestern Gulf of Mexico
HAPC zones in the western section of the northwestern Gulf of Mexico

An additional level of designation, a Coral HAPC, does carry regulations that prohibit fishing vessels from using bottom longlines, bottom trawling, buoy gear, pots or traps and bottom anchoring. In the northwestern Gulf of Mexico, both East and West Flower Garden Banks and McGrail Bank carry this designation due to their significant coral reefs. 

Map showing Habitat Areas of Particular Concern (HAPCs) in the eastern portion of the northwestern Gulf of Mexico
HAPC zones in the eastern section of the northwestern Gulf of Mexico

The Gulf of Mexico Fishery Management Council agreed to include Stetson Bank under the Coral HAPC designation, as well, in order to avoid future confusion by users of different parts of the sanctuary. 

Banks in Brief

Following is a selection of reefs and banks of the northwestern Gulf of Mexico, listed from west to east. Click on each bank name for more detailed information and images.

Horseshoe Bank - named by sanctuary staff for its shape

MacNeil Bank - named for F. Stearns MacNeil, a U.S. Geological Survey geologist

Rankin Bank - named for John L. Rankin of Minerals Management Service

28 Fathom Bank - named for its depth

Bright Bank - named for Thomas Bright, a Texas A&M University marine biologist

Geyer Bank - named for Richard A. Geyer, a Texas A&M University geophysicist

Elvers Bank - named for Douglas J. Elvers, a Minerals Management Service geophysicist

McGrail Bank (formerly 18 Fathom Bank) - named for David W. McGrail, a Texas A&M and Coast Guard oceanographer

Sonnier Bank (formerly Three Hickey Rocks or Candy Mountain) - named for Farley Sonnier, an offshore wildlife photographer

Bouma Bank - named for Arnold H. Bouma, an LSU geologist

Bryant Bank - named for William R. Bryant, a Texas A&M University geologist

Rezak Bank - named for Richard Rezak, a Texas A&M University oceanographer

Sidner Bank - named for Bruce Sidner, a Texas A&M University geologist

Parker Bank - named for Frances L. Parker, an oceanographer from Scripps

Alderdice Bank - named for Robert Alderdice, founder of Flower Garden Ocean Research Center (FGORC)