Mission: Iconic Reefs and National Coral Reef Monitoring Program Benthic Analyses

Summary Report for 2022 and 2024

Published

September 24, 2025

NOAA Logo
Mission Iconic Reef Logo
Authors:
Nicole Krampitz1, Dione Swanson2,3, Julia Mateski1, Lexie Sturm4, Shay Viehman4
1 CSS, Inc. under contract to NOAA National Ocean Service, National Centers for Coastal Ocean Science
2 NOAA National Marine Fisheries Service, Southeast Fisheries Science Center
3 University of Miami, Cooperative Institute for Marine and Atmospheric Studies
4 NOAA National Ocean Service, National Centers for Coastal Ocean Science

1 Introduction

Mission: Iconic Reefs (M:IR) is a multi-institutional initiative designed to restore ecological function and biodiversity across key reef sites in the Florida Keys. Led by NOAA in collaboration with federal, state, institutional, and non-profit partners, M:IR targets nearly three million square feet of reef at seven key coral reefs in the Florida Keys National Marine Sanctuary (FKNMS): Carysfort (North and South), Cheeca Rocks, Eastern Dry Rocks, Horseshoe Reef, Looe Key, Newfound Harbor, and Sombrero Reef (Figure 1). Across these reefs, M:IR aims to restore coral cover to an average of 25% across the seven sites – an inititaitve unparalleled in scope and scale that will require hundreds of thousands of coral restoration outplants and over a decade of phased intervention. 

Figure 1: Map of the Florida Keys showing the sites of Mission: Iconic Reefs

These Iconic reefs were selected for restoration due to their diversity in reef types, levels of anthropogenic disturbances, initial coral cover, geographic distribution, and cultural significance. Restoration progress at these reefs is informed by ongoing monitoring of coral reef benthic communities and coral populations at M:IR sites using a range of metrics, such as coral cover, size structure, mortality prevalence, and diversity. Such multi-metric monitoring is essential to evaluating whether current restoration practices are effective in establishing and maintaining a healthy coral reef, as restoration ‘success’ encompasses a range of ecological and management metrics rather than a single measurement (e.g., coral cover) (Goergen et al., 2020).

In addition to monitoring within the M:IR reefs, it is also important to assess the surrounding reefs in the Florida Keys to interpret restoration progress. The National Coral Reef Monitoring Program (NCRMP), which conducts standardized reef assessments across the Florida Keys on a biennial basis, provides a solid framework for comparison. To align with this program, the M:IR team applied NCRMP survey methodology within its Iconic Sites in 2022 and 2024 to complement NCRMP surveys. These surveys focused on shallow (<30 m), hard-bottom reef habitats, using a stratified-random, one-stage design within 50 m × 50 m grid cells to ensure representative sampling across depth and rugosity strata (Ault et al., 2021). The survey design ensures that survey sites are allocated by cross-shelf zone, rugosity type, and depth strata, with sites distributed around the Florida Keys from nearshore to offshore to a maximum depth of 30 m. The NCRMP sample grid was spatially joined with the seven distinct M:IR zones (Figure 1). Survey sites were proportionally allocated within NCRMP strata to maintain consistent representation across habitats. 

Corals and benthic communities were monitored using two different NCRMP surveys: the Benthic Community Assessment survey and the Coral Demographics survey (NOAA CRCP 2022a, 2022b, 2024a, 2024b). The Benthic Community Assessment survey includes: 1) benthic cover (%) estimates along a 15-m transect with a line point intercept method, 2) presence/absence of Endangered Species Act (ESA)-listed coral species (NOAA National Marine Fisheries Service, 2014), 3) abundance of key macroinvertebrates, and 4) reef rugosity measurements within a 15 m x 2 m belt-transect area (NOAA CRCP 2022a, 2024b). At the same site, coral demographics were surveyed within a 10 m x 1 m belt-transect area (NOAA CRCP 2022b, 2024b). NCRMP coral demographic survey data were combined with complementarily allocated survey data from Florida Fish and Wildlife Conservation Commission’s Disturbance Response Monitoring (DRM). In all coral demographics surveys, all live coral colonies ≧ 4 cm were counted, identified to species, measured to the nearest centimeter, and estimates were made of the proportion per colony of any present mortality (recent or old), disease (absent, present: slow, fast), and/or bleaching (none, total, partial, paling). Only live coral colonies were included in the survey; dead colonies with 100% mortality were not surveyed (e.g., colonies killed by coral disease). Juvenile corals (< 4 cm) were reported for species richness only and were not included in counts, size measurements, or estimates of condition (NOAA CRCP 2022b); in 2024, juveniles of select coral species were counted (NOAA CRCP 2024b). In 2024, NCRMP benthic surveys also included large area imaging (LAI) collected at most survey sites; analyses of these LAI data are in progress and not presented here.

To allow for direct comparisons of benthic communities inside the M:IR restoration areas with control, non-restored areas across the Florida Keys reefs, the NCRMP dataset was restricted to strata types and depth zones (0-12 m) found within M:IR sites. Statistical comparisons were conducted using a two-tailed t-test between M:IR and NCRMP estimates for each survey year (2022 or 2024) and between years for M:IR and NCRMP. This report focuses on coral populations and benthic community metrics; a separate report can be found for fish population assessments (Blondeau et al., 2025).

NCRMP analyses scripts for corals and benthic communities are open source and available at NCRMP Benthic R package (Groves et al., 2025).

2 Benthic Survey Effort

In 2022, a total of 584 surveys occurred (Table 1) across 403 sites (Viehman et al., 2023). In 2024, 771 surveys occurred across 542 sites (Grove et al., in prep).

Table 1. Number of demographic (Demo) and benthic community assessment (BCA) surveys completed by M:IR, NCRMP, and DRM in 2022 and 2024.
M:IR
NCRMP
DRM
Demo BCA Demo BCA Demo
2022 90 89 95 92 218
2024 100 100 129 129 313
Total 190 189 224 221 531

2.1 Coral Demography

For the purpose of this comparison, surveys were divided into two groups: inside M:IR and outside. Almost all of the inside (M:IR) surveys were completed by the M:IR team; however, if an NCRMP or DRM sample happened to fall within the boundaries of an M:IR iconic reef, it was added to the inside group. The inverse occurred if an M:IR survey happened to fall outside the M:IR boundary.

Table 2. The number of coral demographic sites sampled inside and outside M:IR areas in each stratum (includes DRM data).
Study Area Strata Name Strat Description 2022 Sample Number 2024 Sample Number
Inside (M:IR) CFK01 Inshore reef, all relief types and depths 12 10
Inside (M:IR) CFK02 Mid-channel patch reef, all relief types and depths 16 12
Inside (M:IR) CFK03 Offshore patch reef, all relief types and depths 7 11
Inside (M:IR) CFK04 Forereef, low relief, shallow (0-6 m) -- 4
Inside (M:IR) CFK05 Forereef, high relief, shallow (0-6 m) 25 38
Inside (M:IR) CFK06 Forereef, low relief, mid-shallow (6-12 m) 4 12
Inside (M:IR) CFK07 Forereef, high relief, mid-shallow (6-12 m) 34 34
Outside
(NCRMP + DRM)
CFK01 Inshore reef, all relief types and depths 27 24
Outside
(NCRMP + DRM)
CFK02 Mid-channel patch reef, all relief types and depths 79 109
Outside
(NCRMP + DRM)
CFK03 Offshore patch reef, all relief types and depths 37 42
Outside
(NCRMP + DRM)
CFK04 Forereef, low relief, shallow (0-6 m) 4 31
Outside
(NCRMP + DRM)
CFK05 Forereef, high relief, shallow (0-6 m) 21 45
Outside
(NCRMP + DRM)
CFK06 Forereef, low relief, mid-shallow (6-12 m) 19 33
Outside
(NCRMP + DRM)
CFK07 Forereef, high relief, mid-shallow (6-12 m) 60 61

2.2 Benthic Composition

Disturbance Response Monitoring (DRM) only performs coral demographic surveys (Table 1) and therefore DRM surveys are not included in the summary of Benthic Community Assesement surveys (Table 3).

Table 3. Number of Benthic Commnity Assesement (BCA) sites sampled inside and outside M:IR areas in each stratum.
Study Area Strata Name Strat Description 2022 Sample Number 2024 Sample Number
Inside (M:IR) CFK01 Inshore reef, all relief types and depths 8 10
Inside (M:IR) CFK02 Mid-channel patch reef, all relief types and depths 12 12
Inside (M:IR) CFK03 Offshore patch reef, all relief types and depths 7 8
Inside (M:IR) CFK04 Forereef, low relief, shallow (0-6 m) -- 3
Inside (M:IR) CFK05 Forereef, high relief, shallow (0-6 m) 24 33
Inside (M:IR) CFK06 Forereef, low relief, mid-shallow (6-12 m) 4 9
Inside (M:IR) CFK07 Forereef, high relief, mid-shallow (6-12 m) 32 28
Outside (NCRMP) CFK01 Inshore reef, all relief types and depths 10 9
Outside (NCRMP) CFK02 Mid-channel patch reef, all relief types and depths 21 13
Outside (NCRMP) CFK03 Offshore patch reef, all relief types and depths 9 8
Outside (NCRMP) CFK04 Forereef, low relief, shallow (0-6 m) -- 6
Outside (NCRMP) CFK05 Forereef, high relief, shallow (0-6 m) 7 9
Outside (NCRMP) CFK06 Forereef, low relief, mid-shallow (6-12 m) 9 7
Outside (NCRMP) CFK07 Forereef, high relief, mid-shallow (6-12 m) 10 28

3 Benthic Community Composition

Temporal trends in benthic cover of functional groups such as coral and macroalgae cover provide information on changes to the benthic community composition over time.

Figure 2. Cover estimates for main benthic groups inside and outside M:IR areas for 2022 and 2024. A black (+) indicates a significant difference between groups in that survey year (i.e., 2022 or 2024). A colored (*) indicates significance difference between years for the given group (i.e., M:IR or NCRMP). The category ‘Other’ comprises Cyanobacteria, Palythoa, Millepora, Seagrass, bare substrate, and other miscellaneous organisms.

Figure 2. Cover estimates for main benthic groups inside and outside M:IR areas for 2022 and 2024. A black (+) indicates a significant difference between groups in that survey year (i.e., 2022 or 2024). A colored (*) indicates significance difference between years for the given group (i.e., M:IR or NCRMP). The category ‘Other’ comprises Cyanobacteria, Palythoa, Millepora, Seagrass, bare substrate, and other miscellaneous organisms.

Figure 2. Cover estimates for main benthic groups inside and outside M:IR areas for 2022 and 2024. A black (+) indicates a significant difference between groups in that survey year (i.e., 2022 or 2024). A colored (*) indicates significance difference between years for the given group (i.e., M:IR or NCRMP). The category ‘Other’ comprises Cyanobacteria, Palythoa, Millepora, Seagrass, bare substrate, and other miscellaneous organisms.

Figure 2. Cover estimates for main benthic groups inside and outside M:IR areas for 2022 and 2024. A black (+) indicates a significant difference between groups in that survey year (i.e., 2022 or 2024). A colored (*) indicates significance difference between years for the given group (i.e., M:IR or NCRMP). The category ‘Other’ comprises Cyanobacteria, Palythoa, Millepora, Seagrass, bare substrate, and other miscellaneous organisms.

Figure 2. Cover estimates for main benthic groups inside and outside M:IR areas for 2022 and 2024. A black (+) indicates a significant difference between groups in that survey year (i.e., 2022 or 2024). A colored (*) indicates significance difference between years for the given group (i.e., M:IR or NCRMP). The category ‘Other’ comprises Cyanobacteria, Palythoa, Millepora, Seagrass, bare substrate, and other miscellaneous organisms.

Figure 2. Cover estimates for main benthic groups inside and outside M:IR areas for 2022 and 2024. A black (+) indicates a significant difference between groups in that survey year (i.e., 2022 or 2024). A colored (*) indicates significance difference between years for the given group (i.e., M:IR or NCRMP). The category ‘Other’ comprises Cyanobacteria, Palythoa, Millepora, Seagrass, bare substrate, and other miscellaneous organisms.

Figure 2. Cover estimates for main benthic groups inside and outside M:IR areas for 2022 and 2024. A black (+) indicates a significant difference between groups in that survey year (i.e., 2022 or 2024). A colored (*) indicates significance difference between years for the given group (i.e., M:IR or NCRMP). The category ‘Other’ comprises Cyanobacteria, Palythoa, Millepora, Seagrass, bare substrate, and other miscellaneous organisms.

Figure 2. Cover estimates for main benthic groups inside and outside M:IR areas for 2022 and 2024. A black (+) indicates a significant difference between groups in that survey year (i.e., 2022 or 2024). A colored (*) indicates significance difference between years for the given group (i.e., M:IR or NCRMP). The category ‘Other’ comprises Cyanobacteria, Palythoa, Millepora, Seagrass, bare substrate, and other miscellaneous organisms.

4 Coral Demography

Although several metrics reported here encompass all observed coral species, ten focal species are highlighted as particularly important to M:IR’s goal: Acropora palmata, Acropora cervicornis, Colpophyllia natans, Dendrogyra cylindrus, Dichocoenia stokesii, Diploria labyrinthiformis, Meandrina meandrites, Montastraea cavernosa, Pseudodiploria clivosa, and Pseudodiploria strigosa. These species have experienced drastic population declines and are targeted for restoration at the M:IR sites. Specifically, most were severely affected by White Band Disease (Acropora spp.) or Stony Coral Tissue Loss Disease (SCTLD).  

The following table summarizes the number of observations across all strata and survey years of each focal species and identifies the most abundant species encountered.

Table 4. Number of colonies observed for focal M:IR species and the most commonly encountered non-focal species in 2022 and 2024.
Species Colonies in 2022 Colonies in 2024
Siderastrea siderea 3,868 5,618
Porites astreoides 2,657 2,132
Stephanocoenia intersepta 1,345 1,534
Agaricia agaricites 884 237
Porites porites 776 558
*Montastraea cavernosa 437 645
Orbicella faveolata 266 237
Orbicella annularis 211 156
Siderastrea radians 182 328
Porites furcata 160 77
Porites divaricata 118 100
*Dichocoenia stokesii 106 137
*Colpophyllia natans 103 76
Solenastrea bournoni 79 113
*Acropora cervicornis 74 13
*Diploria labyrinthiformis 50 65
*Pseudodiploria strigosa 50 46
Eusmilia fastigiata 45 75
*Pseudodiploria clivosa 23 31
*Acropora palmata 14 0
*Meandrina meandrites 5 11
* indicates M:IR focal species

4.1 Focal Species

The stratified random surveys are designed to optimize sampling efficiency and provide high precision estimates of coral population metrics at relatively low sample sizes (Smith et al., 2011).  The effectiveness of restoration can be quantified by comparison of these metrics between M:IR sites and similar habitats outside these restoration areas. 

The following figures for these metrics are grouped by each focal species. Significant statistical differences using a two-tailed t-test are indicated for differences between survey years (2022 vs. 2024) and between areas (M:IR vs. NCRMP) for density, old mortality, and mean colony size.

Figure 3. Coral density, old mortality, colony size, and size frequency distribution for focal M:IR species across sample years (2022 and 2024) and survey types (M:IR and NCRMP + DRM). A black plus (+) indicates a significant difference in cover estimates between groups in that survey year (i.e., 2022 or 2024). A colored asterisk (*) indicates significance between years for the given group (i.e., M:IR or NCRMP). Note: Axis bounds vary by species.

Figure 3. Coral density, old mortality, colony size, and size frequency distribution for focal M:IR species across sample years (2022 and 2024) and survey types (M:IR and NCRMP + DRM). A black plus (+) indicates a significant difference in cover estimates between groups in that survey year (i.e., 2022 or 2024). A colored asterisk (*) indicates significance between years for the given group (i.e., M:IR or NCRMP). Note: Axis bounds vary by species.

Figure 3. Coral density, old mortality, colony size, and size frequency distribution for focal M:IR species across sample years (2022 and 2024) and survey types (M:IR and NCRMP + DRM). A black plus (+) indicates a significant difference in cover estimates between groups in that survey year (i.e., 2022 or 2024). A colored asterisk (*) indicates significance between years for the given group (i.e., M:IR or NCRMP). Note: Axis bounds vary by species.

Figure 3. Coral density, old mortality, colony size, and size frequency distribution for focal M:IR species across sample years (2022 and 2024) and survey types (M:IR and NCRMP + DRM). A black plus (+) indicates a significant difference in cover estimates between groups in that survey year (i.e., 2022 or 2024). A colored asterisk (*) indicates significance between years for the given group (i.e., M:IR or NCRMP). Note: Axis bounds vary by species.

Figure 3. Coral density, old mortality, colony size, and size frequency distribution for focal M:IR species across sample years (2022 and 2024) and survey types (M:IR and NCRMP + DRM). A black plus (+) indicates a significant difference in cover estimates between groups in that survey year (i.e., 2022 or 2024). A colored asterisk (*) indicates significance between years for the given group (i.e., M:IR or NCRMP). Note: Axis bounds vary by species.

Figure 3. Coral density, old mortality, colony size, and size frequency distribution for focal M:IR species across sample years (2022 and 2024) and survey types (M:IR and NCRMP + DRM). A black plus (+) indicates a significant difference in cover estimates between groups in that survey year (i.e., 2022 or 2024). A colored asterisk (*) indicates significance between years for the given group (i.e., M:IR or NCRMP). Note: Axis bounds vary by species.

Figure 3. Coral density, old mortality, colony size, and size frequency distribution for focal M:IR species across sample years (2022 and 2024) and survey types (M:IR and NCRMP + DRM). A black plus (+) indicates a significant difference in cover estimates between groups in that survey year (i.e., 2022 or 2024). A colored asterisk (*) indicates significance between years for the given group (i.e., M:IR or NCRMP). Note: Axis bounds vary by species.

Figure 3. Coral density, old mortality, colony size, and size frequency distribution for focal M:IR species across sample years (2022 and 2024) and survey types (M:IR and NCRMP + DRM). A black plus (+) indicates a significant difference in cover estimates between groups in that survey year (i.e., 2022 or 2024). A colored asterisk (*) indicates significance between years for the given group (i.e., M:IR or NCRMP). Note: Axis bounds vary by species.

Figure 3. Coral density, old mortality, colony size, and size frequency distribution for focal M:IR species across sample years (2022 and 2024) and survey types (M:IR and NCRMP + DRM). A black plus (+) indicates a significant difference in cover estimates between groups in that survey year (i.e., 2022 or 2024). A colored asterisk (*) indicates significance between years for the given group (i.e., M:IR or NCRMP). Note: Axis bounds vary by species.

4.2 Coral Density

Figure 4. Species-specific coral density (colones/m2) outside (NCRMP and DRM) and inside M:IR areas in 2022 and 2024. Focal M:IR species are denoted with a (*).

4.3 Old Mortality

Figure 5. Percent old mortality (± SEM) by coral species outside (NCRMP and DRM) and inside M:IR areas in 2022 and 2024. Focal M:IR species are denoted with a (*).

4.4 Coral Size

Figure 6. Maximum diameter (cm) ± SEM by coral species outside (NCRMP and DRM) and inside M:IR areas in 2022 and 2024. Focal M:IR species are denoted with a (*).

4.5 Bleaching Estimates

Figure 7. Species-specific bleaching frequency observed outside (NCRMP + DRM) and inside M:IR areas. Focal M:IR species are denoted with a (*).

4.6 Disease Estimates

Figure 8. Species-specific disease frequency observed outside (NCRMP + DRM) and inside M:IR areas. Focal M:IR species are denoted with a (*).

5 Point of Contact

NCRMP Atlantic Benthic Team Lead: Shay Viehman (shay.viehman@noaa.gov)

6 References

Ault, J. S., Smith, S. G., Luo, J., Grove, L. J., Johnson, M. W., & Blondeau, J. (2021). Refinement of the Southern Florida Reef Tract Benthic Habitat Map with Habitat Use Patterns of Reef Fish Species [Dataset]. NOAA National Centers for Environmental Information. https://www.ncei.noaa.gov/archive/accession/0224176
Blondeau, J. B., Grove, J., & Harper, R. (2025). Mission: Iconic Reefs RVC Analysis. NOAA Coral Reef Conservation Program.
Goergen, E. A., Schopmeyer, S., Moulding, A. L., & Moura, A. (2020). Coral Reef Restoration Monitoring Guide: Methods to evaluate restoration success from local to ecosystem scales (Technical Report NOS NCCOS 279). National Oceanic; Atmospheric Administration. https://doi.org/10.25923/xndz-h538
Grove, L. J. W., Viehman, T. S., Blondeau, J., Cain, E., Edwards, K. F., Krampitz, N., Langwiser, C., Mateski, J., Sturm, A. B., Swanson, D., & Towle, E. K. (in prep). National Coral Reef Monitoring Program, Biological Monitoring Summary – Florida: 2024 [Technical Memorandum NOS CRCP, in preparation]. NOAA.
Groves, S., Mateski, J., Krampitz, N., Sturm, A. M., & Viehman, T. S. (2025). NCRMP benthics statistical package in R (website). R package version 1.0.0. https://github.com/MSE-NCCOS-NOAA/NCRMP_benthics
NOAA Coral Reef Conservation Program (CRCP). (2024a). National Coral Reef Monitoring Program (NCRMP) Benthic Community Assessment Survey Field Protocols for U.S. Atlantic: Florida, Flower Garden Banks, Puerto Rico, and U.S. Virgin Islands (p. 29). NOAA Coral Reef Conservation Program. https://doi.org/10.25923/e3gf-vk84
NOAA Coral Reef Conservation Program (CRCP). (2024b). National Coral Reef Monitoring Program (NCRMP) Coral Demographics Survey Field Protocols for U.S. Atlantic: Florida, Flower Garden Banks, Puerto Rico, and U.S. Virgin Islands (p. 28). NOAA Coral Reef Conservation Program. https://doi.org/10.25923/hgpr-jm80
NOAA Coral Reef Conservation Program (NOAA CRCP). (2022a). National Coral Reef Monitoring Program (NCRMP) Benthic Community Assessment Survey Field Protocols for U.S. Atlantic: Florida, Flower Garden Banks, Puerto Rico, and U.S. Virgin Islands–2022. NOAA Coral Reef Conservation Program. https://doi.org/10.25923/0708-8333
NOAA Coral Reef Conservation Program [NOAA]. (2022b). National Coral Reef Monitoring Program (NCRMP) Coral Demographics Survey Field Protocols for U.S. Atlantic: Florida, Flower Garden Banks, Puerto Rico, and U.S. Virgin Islands–2022. NOAA Coral Reef Conservation Program. https://doi.org/10.25923/9a1r-m911
NOAA National Marine Fisheries Service. (2014). Endangered and Threatened Wildlife and Plants: Final Listing Determinations on Proposal to List 66 Reef-Building Coral Species and to Reclassify Elkhorn and Staghorn Corals. Federal Register, 79(175), 53851–54123.
Smith, S. G., Swanson, D. W., Chiappone, M., Miller, S. L., & Ault, J. S. (2011). Probability sampling of stony coral populations in the florida keys. Environmental Monitoring and Assessment, 183(1–4), 121–138. https://doi.org/10.1007/s10661-011-1912-2
Viehman, T. S., Grove, J. G., Blondeau, J., Cain, E., Edwards, K. F., Groves, S. H., Krampitz, N., Langwiser, C., Siceloff, L., Swanson, D., Towle, E. K., & Williams, B. (2023). National Coral Reef Monitoring Program, Biological Monitoring Summary – Florida: 2022 [Technical Memorandum NOS CRCP 48]. NOAA. https://doi.org/10.25923/e6xg-1989


Data Sources:

NOAA National Centers for Coastal Ocean Science; NOAA Southeast Fisheries Science Center (2024). National Coral Reef Monitoring Program: Assessment of coral reef benthic communities in Florida [2022, 2024]. NOAA National Centers for Environmental Information. Dataset. doi: 10.7289/v5xw4h4z

Florida Fish and Wildlife Conservation Commission’s Disturbance Response Monitoring (DRM)