The National Coral Reef Monitoring Program (NCRMP) led by NOAA’s Coral Reef Conservation Program is the largest monitoring effort globally to support the conservation of reefs. Scientists with NOAA’s AOML Coral Program and the Cooperative Institute for Marine and Atmospheric Studies (CIMAS) lead the monitoring efforts in the Gulf of America, Caribbean and the Atlantic Ocean.
From Flower Garden Banks National Marine Sanctuary (FGBNMS) in the Gulf to reefs throughout the Florida Keys National Marine Sanctuary (FKNMS), Dry Tortugas National Park, Puerto Rico and the U.S. Virgin Islands – scientists at AOML deploy instruments examining environmental conditions, and conduct photomosaic surveys feeding into advanced models to holistically track major trends and changes to critical reef infrastructure.
Map conveying the regions where AOML’s Coral Program performs long-term environmental monitoring as part of the National Coral Reef Monitoring Program.
Following a three-year cycle of field operations in each region, researchers have returned to FGBNMS off the coast of Texas and St. Croix in the U.S. Virgin Islands. Now, they are preparing to return to vital sites throughout the Florida Keys National Marine Sanctuary, a region known to contribute billions in flood risk reduction benefits, tourism, and fishing to Florida’s economy alone.
When examining the health of a reef, they assess two key components – the conditions a coral reef has been exposed to, and how the coral reef persisted with these conditions.
To assess environmental conditions, they deploy a series of instruments at designated sites for each reef – returning every three years to recover them, analyze the data and deploy new ones.
The subsurface temperature recorder (STR) tracks changes in temperature on the reef over the three-year period. To assess a reef’s biological response to given conditions, the team deploys Bioerosion Monitoring Units (BMU’s) and Calcification Accretion Units (CAU’s) to quantify accretion or coral growth and bioerosion at select sites.
During field operations within each region, they deploy short-term instruments to measure changes in the ocean’s pH, the reef’s exposure to sunlight available for photosynthesis, and collect observations of the current.
They also deploy the Subsurface Automated Sampler (SAS) – an instrument designed and engineered by AOML’s Coral Program – to collect seawater samples multiple times a day to unlock key insights into the carbonate chemistry. By analyzing the carbonate chemistry of these samples at AOML, the team can examine the degree and intensity of ocean acidification.
Carbonate budget surveys allow the team to quantify benthic coral cover (i.e. the amount of coral in an area), which contributes to reef growth and the amount of known organisms eroding reef structure, including sponges, parrotfish and sea urchins. This provides an estimate of whether a reef is net growing or net eroding. In addition, to effectively assess major changes to large tracts of coral reefs, the team performs photomosaic modeling.
Scientists at AOML perform a carbonate budget survey and photomosaic survey to examine the persistence of the valuable reef structure at FGBNMS.
At FGBNMS, coral cores were also extracted that will enable the team to assess the corals’ historical growth and calcification rates of corals – and correlate them with past climate events.
With all of these parameters, scientists at AOML examine long-term changes to reefs across each region compared to historical baselines set by NOAA’s Coral Reef Conservation Program.
Combining pre-existing data of biological and physical conditions of vital reef infrastructure across the ten priority geographic areas with coordinated monitoring efforts, CRCP worked to develop a critical understanding of how coral reefs have fared historically since its inception in 2001 – while also considering human influences and socioeconomic impacts.
The status report for U.S. coral reefs that resulted was the first scientific analysis of its kind to set comprehensive historical baselines for the variety of environmental conditions and indicators across coral reefs in each jurisdiction of the U.S.
As scientists at AOML return from field operations and NCRMP monitoring efforts, they are beginning to analyze the data and assess reef persistence across Flower Garden Banks and St. Croix – while preparing for future operations throughout the Florida Keys.
Each of these regions have been impacted by coral bleaching events and the 2023 marine heatwave in the last three years. Diseases – specifically, Stony Coral Tissue Loss Disease – continue to spread rapidly across the Caribbean. And while the impacts of ocean acidification are being buffered against in some regions, it is exacerbated in other regions.
This is what makes long-term monitoring efforts a necessity.
Understanding the true intensity of ocean warming, acidification, and coral disease across different regions fuels experimentation, including those currently being performed within the Experimental Reef Lab, which is located at the University of Miami’s Rosenstiel School.
Assessing the impacts of environmental stressors on reefs across years and decades does not just benefit our understanding of the biodiversity they host and the health of marine ecosystems – but the trajectory of entire economies.
Learn more about the National Coral Reef Monitoring Program here: https://www.coris.noaa.gov/monitoring/
Ian Enochs, Ph.D., Lead of the AOML Coral Program, is the Principal Investigator on this effort.
Scientists at AOML descending the line on a reef within Flower Garden Banks National Marine Sanctuary in August 2025.