IMAGE: Mission: Iconic Reefs field team member Cate Gelston, co-lead scientist on the assessment cruise, retrieves a transect tape after completing an outplant coral health assessment survey. CREDIT: Ben Edmonds/NOAA.
February 15, 2024 (Key West, FL.) – A team of researchers from NOAA’s Mission: Iconic Reefs program and partners from Mote Marine Laboratory & Aquarium and the Coral Restoration Foundation completed a scientific mission yesterday to quantify the impact of 2023’s marine heat wave on restored corals in Florida Keys National Marine Sanctuary. Data from the research cruise will help NOAA and partners understand the extent of the record-high marine temperatures from the summer of 2023 on restored corals — which are nursery-raised and out-planted on the reef — and inform future restoration strategies to increase coral resilience.
Researchers aboard the contracted vessel M/V Makai surveyed 64 sample areas across five of the seven Mission: Iconic Reef sites – Carysfort Reef, Horseshoe Reef, Sombrero Reef, Looe Key Reef, and Eastern Dry Rocks– to examine the reef-building stony acroporid corals out-planted by Coral Restoration Foundation, Mote Marine Laboratory & Aquarium, and Reef Renewal.
This research follows a mission in August that assessed the health of coral out-plants during the height of the marine heat wave and incorporates data about how eight additional weeks of high temperatures affected them.
Preliminary findings from the latest assessment provide insights into the current state of out-planted coral health:
- Preliminary data indicate that less than 22% of approximately 1,500 out-planted staghorn coral (Acropora cervicornis) surveyed remain alive.
- Living staghorn coral out-plants were found and surveyed at Carysfort Reef and Horseshoe Reef, the two most northern Mission: Iconic Reefs sites.
- Preliminary data indicate that 4.9% of about 1000 out-planted elkhorn coral (Acropora palmata) surveyed remain alive.
- Living elkhorn coral out-plants were found and surveyed at Carysfort Reef, Sombrero Reef in the middle Keys and Eastern Dry Rocks off Key West.
- No live outplanted staghorn or elkhorn corals were observed at sample areas surveyed at Looe Key Reef in the lower Keys.
All data collected during the assessment is currently undergoing thorough review and analysis.
Due to rough weather conditions, researchers surveyed only living staghorn and elkhorn coral out-plants at the five Mission: Iconic Reefs sites but did observe many healthy and thriving wild and out-planted boulder, massive, and brain corals, which are also important components of the reef ecosystem and the Mission: Iconic Reefs restoration plan.
“The findings from this assessment are critical to understanding the impacts to corals throughout the Florida Keys following the unprecedented marine heatwave,” said Sarah Fangman, Florida Keys National Marine Sanctuary superintendent. “They also offer a glimpse into coral’s future in a warming world. When the ecosystem experiences significant stress in this way, it underscores the urgency for implementing updates to our regulations, like the Restoration Blueprint, which addresses multiple threats that will give nature a chance to hold on.”
Florida’s coral reefs are the backbone of the region’s tourism and recreation economy, and provide important ecological services to coastal communities. The health of Florida’s coral ecosystems has declined since the 1970s due to damage from hurricanes, heat-induced bleaching, disease and increased impacts from human activities.
The assessment will support the ongoing restoration efforts of Mission: Iconic Reefs, a NOAA-led, partner-driven initiative to restore nearly 3 million square feet of coral reef– the equivalent of more than 50 football fields — at seven iconic sites within Florida Keys National Marine Sanctuary, through pioneering restoration efforts involving growing and transplanting corals. The goal is to restore diversity and ecological function to the reefs by returning coral cover at target reef sites to a self-sustaining level.
In the summer of 2023, corals in the Florida Keys faced the hottest ocean temperatures on record, and the longest-lasting marine heat wave recorded in three decades. The marine heat wave prompted emergency evacuation of in-water nursery corals to land-based nurseries to limit heat exposure. Collaboration between Mission: Iconic Reefs and coral conservation practitioners safeguarded the genetic diversity of coral reef-building species.
“We are fortunate to have the unwavering dedication and expertise of multiple partners collaborating with NOAA to restore this critical ecosystem,” said Jennifer Mooore, co-lead of Mission:Iconic Reefs and Endangered Species Act coral recovery coordinator for NOAA Fisheries. “The assessment results, complementary research efforts from partners and lessons from emergency activities over the summer will inform effective and innovative restoration strategies to support the health of Florida’s coral reefs.”
Learn more about NOAA’s response to the 2023 marine heatwave and MIssion: Iconic Reefs coral restoration efforts in Florida Keys National Marine Sanctuary:
- Mission: Iconic Reefs website
- Photos from February 2024 assessment.
- Resources for reporters on coral bleaching event in the Florida Keys
- August 2023 news release on protocols for returning temperature-threatened corals to in-water nurseries
- Florida Keys National Marine Sanctuary Restoration Blueprint
- Marine heat waves explained
- Restoring Seven Iconic Reefs: A Mission to Recover the Coral Reefs of the Florida Keys
- Podcast: Restoring Florida’s Iconic Coral Reefs