MIAMI— Staghorn corals grown in a nursery and replanted at a reef restoration site off Key Biscayne have spawned for the first time, signaling hope that fragmenting corals and outplanting them to reefs is a viable approach to help rebuild Florida’s valuable marine ecosystems.
University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science scientists and collaborators from SECORE International observed restored staghorn corals (Acropora cervicornis) at Rainbow Reef releasing healthy spawn on August 6 and 7, 2020, marking a first for nursery-grown corals outplanted on a reef restoration site in Miami-Dade County.
“It’s a very rare phenomenon to witness, so it’s great that we were able to capture this scientific breakthrough to share with our local community and people around the world,” said Diego Lirman, associate professor of marine biology and ecology at the UM Rosenstiel School and founder and director of UM’s Rescue a Reef program.
The scientists were able to collect eggs and sperm from about a dozen different colonies during the spawning, which they then fertilized to raise thousands of coral larvae which can also be grown out and replanted as part of a cyclical approach to helping reefs rebuild themselves and remain resilient.
“Spawning in the wild is a critical observation that shows that these restored corals now have the ability to naturally replenish reefs through their own reproductive efforts”, said Andrew Baker, professor of marine biology and ecology at the UM Rosenstiel School and director of UM’s Coral Reef Futures Lab. “This is the gold standard for a successful restoration program because it means that the value of our nursery-grown corals is being compounded over time, adding new recruits and new genetic diversity that increase coral cover and resilience to climate change, disease, and other stressors.”
The offspring generated from the spawning event will be reared in labs at the Rosenstiel School, as well as SECORE’s Coral Rearing In-Situ Basins (CRIBs), before being outplanted back to local reefs in Miami-Dade County.
“It is thrilling and important that these corals have spawned. But there is still a very long path with many hazards before these microscopic coral babies grow to be functional members of a thriving population. We also aim to provide assistance through several of their early life stages of these corals, to enhance the chances this spawning event yields new adult corals added to our local reefs,” said Margaret Miller, Research Director for SECORE International.
“As a result of our collection efforts, 90% of the coral eggs were fertilized which is much higher than we see in nature” said Liv Williamson, a UM Rosenstiel School PhD candidate in the Coral Reef Futures Lab who was part of the scientific dive team documenting the spawning event. “Now, these larvae are beginning to ‘settle’, or attach to their permanent homes on the seafloor, or in our case, settlement units that we have provided for them in the lab.”
By settling these juveniles under controlled conditions without predation or environmental stress, the researchers are maximizing the survival of these young corals prior to outplanting.
The event included several spawning corals planted onto the 100 Yards of Hope restoration site, a football field-sized restoration project on Rainbow Reef honoring the NFL’s 100th season and America’s military veterans of FORCE BLUE.
In June 2019, the UM Rosenstiel School and partners outplanted 100 staghorn corals to the 100 Yards of Hope site as part of the decade-long restoration efforts led by Lirman, that have resulted in over 20,000 nursery-grown corals planted onto degraded reefs in Miami-Dade County. The successful spawning and viable offspring of these corals highlights the capabilities of large-scale reef restoration and coral recovery.
The scientists also observed, collected, and fertilized coral spawn at their underwater coral nursery. In addition, the research team observed several wild mountainous star coral colonies (Orbicella faveolata) spawn at Rainbow Reef. Scientists from the UM-based NOAA Cooperative Institute for Marine and Atmospheric Studies (CIMAS) also aided the team during the spawning expeditions.
The coral spawning and restoration activities are part of the $6 million Southeast Florida Coral Restoration Hub whose goal is to restore 125 acres of reef habitat in Miami-Dade and Broward counties over three years. The project, which began in January, will ultimately grow and plant over 150,000 coral colonies and juveniles from five coral species, three of which are currently listed as threatened. The effort also includes enhancing coral abundance, genetic diversity, reef connectivity, and resilience.
To capture this spectacular event, Canon U.S.A, Inc. provided a specialized camera and Gates underwater housing equipment to the UM Rosenstiel School that was used by renowned underwater cinematographer Peter Zuccarini. This collaboration stemmed from a project Canon and the University of Miami’s Rescue a Reef program embarked on in Nov. 2019 to advance science communication and coral restoration as part of the company’s commitment to environmental sustainability.
Coral reefs, which provide habitat for a wide variety of marine organisms and support valuable commercial and recreational fishing industries, are in decline globally. Florida’s Coral Reef is the only nearshore reef in the continental United States, and coral cover has declined by at least 70 percent since the 1970s. Staghorn coral, once common in shallow waters throughout Florida and the Caribbean, is listed as a threatened species under the Endangered Species Act.
The coral reefs in Southeast Florida generate $2 billion in annual revenues and support 70,400 jobs. In addition, Southeast Florida’s reefs play an important role in protecting people and property from the effects of hurricanes, such as flooding and storm surge, along the highly urbanized coastlines of Miami and Ft. Lauderdale during hurricanes.
The National Fish and Wildlife Foundation’s National Coastal Resilience Fund, developed in partnership with NOAA, Shell Oil Company and TransRe, provided the initial $3 million grant to establish the restoration project. The funds were matched by various donors including local and federal governments, corporations
The project is being led by UM Rosenstiel School Professors Diego Lirman, Andrew Baker, and Brian Haus and partners from UM College of Engineering, NOVA Southeastern University, SECORE International, The Florida Aquarium, the Phillip and Patricia Frost Museum of Science.
The program is amplified through the involvement of citizen scientists from UM’s Rescue a Reef program, where volunteers will work side-by-side with restoration scientists with additional awareness driven by the public-facing labs and displays at the Frost Science Museum and The Florida Aquarium.
