Scientists gather at night to watch annual spawning event to save Florida reefs

SARASOTA, Fla. - Scientists are racing against time to save Florida's dying coral reef through an ambitious project following a rare annual spawning event in the Florida Keys.

Saving Florida coral reefs

What we know:

Twelve environmental organizations joined forces earlier this month to execute a high-stakes coral restoration effort during a short, annual spawning window. 

They include University of Miami Rosenstiel School of Marine Atmospheric, and Earth Science, the Re5 initiative, Reef Renewal USA, The Florida Aquarium, The Reef Institute, The Smithsonian Marine Station, SECORE International, Phillip and Patricia Frost Museum of Science, Nova Southeastern University, John Pennekamp Coral Reef State Park, Biscayne National Park, AECOM  and Mote Marine Laboratory.

The critical event unfolded just after 10 p.m. when elkhorn and staghorn corals released millions of egg and sperm bundles into the water column. Teams of scientists stepped in to collect the genetic material, working to create a resilient new generation of coral.

Dying Florida reefs

The backstory:

Corals across Florida's reef have suffered a severe decline after years of coral bleaching. 

The natural reproductive process has become nearly impossible because surviving coral colonies are too far apart to locate each other in the open water.

Restoring staghorn and elkhorn corals

By the numbers:

Wild coral populations along Florida's reef have plummeted to dangerously low numbers. Only 300 staghorn corals and fewer than 150 elkhorn corals remain in the wild on the reef.

Scientists observed 25 elkhorn genotypes and 36 staghorn genotypes spawning and resulting in 116 unique directional crosses through assisted fertilization and 350 vials of sperm cryopreserved for long-term banking. 

Through a four-year NOAA grant, the collaborative effort yielded major results:

• More than 61,000 elkhorn larvae were successfully produced.
• More than 47,000 staghorn larvae were successfully created.
• Twelve partner organizations collaborated to divide and nurture the larvae.

Cross-breeding resilient corals

What they're saying:

Experts emphasized that pooling resources across multiple facilities creates stronger coral strains capable of surviving rising ocean temperatures and helps safeguard conservation efforts. 

"What makes this really special is all of our partners, such as Reef Renewal USA, The Florida Aquarium, NOAA, Smithsonian, etc. All of us have a large amount of expertise in this field, and we are able to strategically cross these individuals in order to produce corals that are more fit for today’s ocean environment," said Leto. "Not only are we making sure that these corals genetic diversity is being increased but also making sure that the individuals produced are better fit for the warm and more acidic ocean conditions that we are seeing on Florida’s coral reefs."

Leto noted that bringing together diverse nursery populations was key to the project's success.

"What made this process unique is that we are able to go and work with other institutions and populations that they also have that we may not have represented in our nurseries and we are now able to produce these new families and new classes that would never have existed without this collaboration," Leto said.

Returning corals home

What's next:

The newly created larvae were divided among several participating partner organizations, including Reef Renewal USA, The Florida Aquarium and the Smithsonian. 

Research teams will nurture and grow the young corals in controlled environments. 

The ultimate goal is to return the grown corals to nursery sites within two years to establish permanent homes on Florida's natural reefs.