Skip to main content

At A Glance:

  • 40 sites
  • North Key Largo to Key West within the Florida Keys National Marine Sanctuary
  • Monitoring initiated in 1996
  • Sites stratified between Keys subregion and reef type
  • Funded by EPA Water Quality Protection Program
  • Monitoring conducted by FWC

Starting in 1996, CREMP was originally designed to document the status of reefs located within 5 of the 9 EPA Water Quality Segments in the Florida Keys National Marine Sanctuary (FKNMS). Approximately 120 mi of the nearly 360 mile long Florida’s Coral Reef is included in CREMP in the Florida Keys, from the southern boundary of Biscayne National Park to the waters off Key West (see map). Sampling sites were selected using a stratified random sampling procedure based on the EPA Environmental Mapping and Assessment Program (EMAP). The EPA, FKNMS, and Continental Shelf Associates worked with FWC to develop monitoring protocols and site selection methods.  

A satellite map of the Florida Keys separated with white lines into the Upper, Middle, and Lower Keys regions. CREMP monitoring sites are shown as green squares for Hardbottom, orange circles for Patch Reef, light blue triangles for Shallow Forereef, purple upside-down triangles for Deep Forereef, and blue circles for Backcountry Patch Reef sites.

Map of the Coral Reef Evaluation and Monitoring Program in the Florida Keys.

Stratification was based on habitat type and Keys region. Four main habitat types were defined as:

An underwater coral reef scene with a school of grey snapper swimming towards the camera and a porgy swimming away. Reef spurs rise up on either side of the fish, with a boulder in the foreground. The reef is mostly bare but covered in many octocorals, with a hazy blue background.

Sombrero Shallow, an example of a shallow forereef site. 

  • Nearshore hardbottom, defined as areas of shallow (<15') low-relief nearshore limestone habitat, generally dominated by octocorals, sponges, and/or algae with limited coral cover. This is the most abundant hardbottom habitat in the Florida Keys.
  • Patch reefs, defined as hardbottom areas with higher relief generally found 2-4mi offshore between Hawks Channel and the forereef. Patch reefs vary in their dominant taxa but have a mixture of stony corals, octocorals, sponges, and algae. This is the second most abundant hardbottom habitat in the Keys.
  • Shallow forereefs, defined as reefs near the reef crest in water approximately 10-20' deep.
  • Deep forereefs, defined as reefs on the reef slope in water 30-60' deep.

The three regions of the Keys – Upper, Middle, and Lower - are defined by their underlying geology and hydrology:

  • The Upper Keys refers to the area south of Biscayne National Park to Upper Matecumbe Key. The Upper Keys is characterized by large islands composed of Key Largo Limestone. Key Largo Limestone is representative of fossil reefs that grew in the Pleistocene and were later exposed and hardened into islands when sea level lowered due to glacial cycles. The orientation of the islands limits water flow between Florida Bay and the Atlantic, and modern reefs are therefore more developed offshore these keys.
  • The Middle Keys are defined as the area from Lower Matecumbe Key to Bahia Honda Key. The islands of the Middle Keys are also composed of Key Largo Limestone but are much smaller than Upper Keys islands and have large tidal channels between Florida Bay and the Atlantic. The mixing of these waters from the Bay over the reef tract resulted in lower reef development in this area.
  • The Lower Keys are defined as the area from Big Pine Key to Key West. The islands of the Lower Keys are large to intermediate in size and composed of Miami Limestone, an oolitic limestone representing ancient tidal sand bars.

While sites were chosen randomly, permanent monitoring stations were installed with the intention of being representative of their selected habitats. In some cases, stations were established to monitor specific stands of corals within that habitat. Station placement ensured adequate coverage over the reef area, and generally span from reef edge to reef interior. All CREMP in the Florida Keys sites have four stations per site.

Currently, 40 sites are surveyed annually in the Florida Keys (see Table 1). Thirty-four of these sites have been continuously sampled since 1996: 17 patch reefs (two in the “backcountry” of the Gulf of Mexico and 15 oceanside), 12 shallow forereef, and 11 deep forereef sites.

Since the onset of the program in 1996, several modifications to the spatial design have occurred.

An underwater scene with a large, white, dead mountainous star coral in the foreground surrounding by clear blue water.

Wonderland, one of the six patch reefs added in 2009. This reef experienced significant coral loss as part of the stony coral tissue loss disease outbreak. 

  • 1996
    • Monitoring started on original 40 sites.
  • 2001
    • Benthic monitoring at six hardbottom sites discontinued due to consistently low coral cover (Rattle Snake, Dove Key, El Radabob, Long Key, Moser Channel, and Molasses Keys).
  • 2009
    • Six patch reefs added to the program (Burrfish, Rawa, Red Dun, Two Patch, Thor, and Wonderland) to increase survey effort on the patch reefs.
    • The hardbottom site Content Keys was reclassified more appropriately as a backcountry patch reef.

Florida Keys CREMP Sites

CREMP in the Florida Keys sites are stratified by Keys region and reef type. Some changes occurred over the lifetime of the program. Hardbottom sites are no longer included in benthic monitoring as of 2001. Originally Content Keys and Smith Shoal were placed in a “Gulf of Mexico” region as a hardbottom and patch reef, respectively. Sombrero Reef was originally put in the Lower Keys region. Jaap Reef was originally categorized as a hardbottom site. See the CREMP in the Florida Keys site table for a full listing of our sites and monitoring timeframe.