Sanctuary Boundaries

Flower Garden Banks National Marine Sanctuary has 19 separate boundary areas encompassing all or part of 17 different reefs and banks off the coasts of Texas and Louisiana. Twelve of the banks have individual boundaries, two of the banks have a shared boundary, and three of the banks have two separate boundary areas each.

Boundary Determination

Many of the sanctuary boundaries were drawn close to No Activity Zone (NAZ) designations set by the Bureau of Ocean Energy Management (BOEM). This was done to limit the impact of sanctuary designation on the oil & gas and fishing industries in the northwestern Gulf of Mexico. As a result of this process, Elvers, McGrail, and Parker Banks each have two boundary areas.

Horseshoe Bank was the only bank without a NAZ so the boundary was drawn relatively close to the mapped features in that area. Rankin and 28 Fathom Banks were combined within one boundary due to their close proximity to one another.

You can view the boundary and NAZ data across the whole sanctuary using the Exploration Tool of the Story Map on our home page.

Boundary Points (NAD83)

Maps and sanctuary boundary points for each of the banks are listed below. These are presented in geographic order from the west end to the east end of the sanctuary, starting with Stetson Bank and ending with Alderdice Bank.

GIS boundary data is available for all national marine sanctuaries here:
https://sanctuaries.noaa.gov/library/imast_gis.html