This geodatabase provides the Final Critical Habitat designations for Nassau grouper, Epinephelus striatus (January 2, 2024). NMFS designates critical habitat for the threatened Nassau grouper pursuant to section 4 of the Endangered Species Act (ESA). Areas designated as critical habitat contain approximately 2,384.67 sq. kilometers (920.73 sq. miles) of aquatic habitat located off the coasts of southeastern Florida, Puerto Rico, Navassa, and the United States Virgin Islands (USVI). The NMFS identified habitats that include features essential to the conservation of Nassau grouper, including areas for spawning and for recruitment and development.

The Nassau grouper is a reef fish, and is a member of the family Serranidae, which includes groupers valued as a major fishery resource such as the gag grouper and the red grouper. These large fish are associated with hard structures like reefs (both natural and artificial), rocks, and ledges. They are late-maturing, long-lived, top-level predators found in tropical and subtropical waters of the western North Atlantic. This includes Bermuda, Florida, Bahamas, the Yucatan Peninsula, and throughout the Caribbean to southern Brazil. Nassau Grouper undergo ontogenetic shifts in habitat utilization: larvae settle in nearshore habitats and then as juveniles move to nearshore patch reefs (Eggleston, 1995), and eventually recruit to deeper waters and reef habitats (Sadovy and Eklund, 1999). As adults, individuals are sedentary except for when they aggregate to spawn - the timing of which appears to be linked to both lunar cycles and water temperature (Kobara et al., 2013). Maximum age has been estimated as 29 years, based on an ageing study using sagittal otoliths (Bush et al., 2006). Maximum size is about 122 cm total length (TL) and maximum weight is about 25 kg (Heemstra and Randall, 1993).

Nassau grouper used to be one of the most common species of grouper in the United States. It was easy for commercial and recreational fisherman to catch Nassau grouper and it soon became scarce. The remaining stocks are overexploited. In some cases, Nassau grouper is commercially extinct through much of its geographical range. Currently, all harvest of Nassau grouper is prohibited in the United States. Nassau grouper is listed as threatened under the Endangered Species Act. NOAA Fisheries is dedicated to the conservation of Nassau grouper.

For more information, please see the official definition and complete description at: https://www.federalregister.gov/documents/2024/01/02/2023-28483/endangered-and-threatened-species-designation-of-critical-habitat-for-the-nassau-grouper

This section provides the Simplified Geographic Description for each unit designated as Nassau Grouper Critical Habitat.

The 20 Designated Critical Habitat Units for Nassau Grouper include:

Navassa Island Unit. Waters surrounding Navassa Island. Area = 2.46 sq. km.

Puerto Rico Unit 1 - Mona Island and Monito. Waters surrounding Mona Island and Monito to the 50m contour. Area = 30.65 sq. km.

Puerto Rico Unit 2 - Desecheo Island. Waters surrounding the island to the 50m contour. Area = 4.28 sq. km.

Puerto Rico Unit 3 - Southwest. Waters off the southwest coast of the Puerto Rico main island. Area = 112.39 sq. km.

Puerto Rico Unit 4 - Northeast. Waters off the northeast coast of the Puerto Rico main island. Area = 48.75 sq. km.

Puerto Rico Unit 5 - Vieques Island. Waters off the west and northeast, east, and southeast coasts of the island. Area = 9.49 sq. km.

Puerto Rico Unit 6 - Culebra/Culebrita Islands. The Culebra area consists of waters off the southeastern Culebra coastline. The Culebrita area consists of waters off the western and southern coasts of the island. Area = 4.15 sq. km.

United States Virgin Island Unit 1- St Thomas. Waters off the east coast of St. Thomas Island and waters off the southwest, south, and southeast coast of the Water Island. Area = 9.18 sq. km.

United States Virgin Island Unit 2- St. John. Waters off the east coast of the island. Area = 6.55 sq. km.

United States Virgin Island Unit 3- St. Croix. Waters off the east end of St. Croix Island and waters off the north coast of Buck Island. Area = 50.35 sq. km.

Florida Unit 1 – Biscayne Bay/Key Largo. Waters south of Rickenbacker Causeway, including portions of waters from the coastline into Biscayne Bay, and waters off the eastern coastline to 80°29'21" W, 25° 01' 59" N. Area = 1,279.69 sq. km.

Florida Unit 2 - Marathon. Waters off the southern shoreline approximately between Knights Key to 80°55'51"W, 24° 46' 26" N. Area = 172.38 sq. km.

Florida Unit 3 - Big Pine Key to Geiger Key. Waters off the south side of coastline and US 1 from approximately Geiger Key to Big Pine Key. Area = 372.37 sq. km.

Florida Unit 4 - Key West. Shoal waters south of Woman Key. Area = 127.09 sq. km.

Florida Unit 5 - New Ground Shoal. New Ground Shoal waters. Area = 31.04 sq. km.

Florida Unit 6 - Halfmoon Shoal. Halfmoon Shoal waters. Area = 33.62 sq. km.

Florida Unit 7 - Dry Tortugas. Waters encompassing Loggerhead Key and waters surrounding Garden Key and Bush Key. Area = 4.43 sq. km.

Spawning Site Unit 1 - Bajo de Sico. All waters encompassed by 100m isobath bounded in the Bajo de Sico spawning area bound within the following coordinates: A) 67°26’13”W, 18°15’23”N, B) 67°23’ 08”W, 18°15’26”N, C) 67°26’ 06”W, 18°12’55”N, and D) 67°26’ 13”W, 18°12’56”N. Area = 10.74 sq. km.

Spawning Site Unit 2 - Grammanik Bank/Hind Bank. All waters which make up the Hind Bank and the Grammanik Bank, interconnecting waters between these banks, and waters extending out to the 200 fathom line directly south from Grammanik Bank. Area = 59.69 sq. km.

Spawning Site Unit 3 - Riley's Hump. All waters encompassing Riley's Hump (centroid 83.1085642°W 24.4948905°N) out to the -35m isobath on the north, west, and east side of the hump, and extending out to the 50m isobath on the south side of the hump to include the escarpment on the southern face of the bank. Area=15.35 sq. km.

Source of Base Data for Unit Boundaries:

The shoreline was created using the existing Acropora critical habitat designation (from NOAA NCCOS Benthic Habitat Mapping 2000-2002 - land and mangrove attribute combined for shoreline). For PR and USVI units, shoreline data using The NCCOS Benthic Habitat Mapping program provides baseline data and maps at https://coastalscience.noaa.gov/project/benthic-habitat-mapping-puerto-rico-virgin-islands/. For the Continental US, this shoreline is consistent with the US Medium Resolution Shoreline.

Contours were derived from the National Geophysical Data Center’s 2004 U.S. Coastal Relief Model https://www.ngdc.noaa.gov/mgg/coastal/crm.html. The NCCOS Benthic Habitat Mapping program provides data and maps at http://products.coastalscience.noaa.gov/collections/benthic/default.aspx, which was used to pull in substrate data. For the Florida Units, benthic substrate and bathymetry data were pulled from the FWC Florida Unified Reef Tract at https://myfwc.com/research/gis/fisheries/unified-reef-map/. Benthic data was also used from The Nature Conservancy and can be downloaded here: https://sites.google.com/view/caribbean-marine-maps.

For Spawning Site Unit 3 - Riley's Hump, bathymetry contours (i.e. isobaths) were pulled from the NCEI's CUDEM, or Continuously Updated Digital Elevation Models. (https://noaa.maps.arcgis.com/home/item.html?id=bf72d32c6a00407bb67a285845a7fa32) The CUDEM Raster was downloaded (Global Mosaic Elevation Values) and clipped to the site in ArcPro. The Contour Tool was set to 5m intervals. The CUDEM is built in 10m increments, as noted using the 1/3 arcseconds. Did not use the 1/9 arc second model, which corresponds to 3 meter increments. The CUDEM uses LiDAR data and is an orthometric vertical datum, and compiles data from NGDC, NOS, USGS, NMFS, etc. For more information, please vist: https://www.ncei.noaa.gov/products/coastal-relief-model. Riley's Hump (the geographic feature, not the critical habitat unit) was identified as the fully enclosed -30m hump located at 83.1085642°W 24.4948905°N (centroid).

Standardized metadata has been prepopulated for the Fields and Values and the standard spatial reference is the World Geodetic System 1984 geographic coordinate system (GCS_WGS_1984, EPSG well-known identifier 4326).

Attribute Values:

Shape = Feature Class, Polygon Data.

ID = Species ID

Scientific Name = Genus species

Common Name = Common Name of species

Listing Status = Federal status of a taxon under the federal Endangered Species Act.

Critical Habitat Status = Status of Critical Habitat Designation (i.e. Proposed or Designated)

Unit = Location of Identified Critical Habitat

Taxon = Taxon

Lead Office = NMFS Regional Office

Federal Register Notice = Public official notice of Rule

Publication Date = Publication Date of Federal Register Notice

Effective Date = Effective Date of Rule

Area SqKm = Area of Unit in Square Kilometers

Create Date = Last Date Polygon and Attribute Data were Modified

Notes = notes

InPort URL = MetaData URL Link (InPort)

Habitat Type = general location of critical habitats

eCFR = Electronic Code of Federal Regulations

Shape_Length = dynamic geodatabase field. Automatically calculated in the units of the output coordinate system specified by the Spatial Reference parameter by ESRI.

Shape_Area = dynamic geodatabase field. Automatically calculated in the units of the output coordinate system specified by the Spatial Reference parameter by ESRI.