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"Talking Science" in April 2022 with the Coral Chronicles


What happens after our divers return corals to the wild? In addition to monitoring our coral outplants through the use of photomosaics, one of the most significant ways to track their performance is to record whether or not they are sexually reproducing, or in coral terms, spawning!

A staghorn coral spawns, releasing gamete bundles from its polyps. ©Alexander Neufeld/Coral Restoration Foundation™

Corals actually reproduce two different ways, making them an incredibly unique animal. The first is through an asexual reproduction, where only one parent is needed. Corals naturally

reproduce asexually through cloning of their own polyps and fragmentation. Fragmentation occurs when a 'branch' of a coral breaks apart from the main colony, usually during a storm. The original colony remains alive and the broken branch can fix itself to a space on the reef and begin growing larger itself! CRF™ harnesses the power of natural fragmentation to propagate corals in our coral nurseries. Through this method we can produce 45,000 reef ready corals each year!

The second method corals use to procreate is sexual reproduction, which takes two parents. In order to sexually reproduce corals release their eggs and sperm in bundles that look like small pink eggs. This act of releasing their gametes into the water column is called 'spawning'.

Spawning occurs in connection with the cycle of the moon and differs depending on species. For elkhorn and staghorn, the dominant reef-building species of the Florida Keys, spawning occurs only once a year between late July and early August. When spawning happens, millions of gametes are released into the water column within seconds of one another, filling the ocean with millions of tiny coral eggs.

CRF™ corals spawn en masse in 2019. ©Coral Restoration Foundation™

Many species, including staghorn and elkhorn, produce both sperm and egg cells that are released with the goal of combining with the cells of a genetically different coral colony. Mixing up the genetic pool like this is known as genetic recombination and heavily contributes to the reef’s natural creation of new genetic material over thousands and millions of years.

CRF™ supported a multi-year study which gathered coral eggs and sperm from our Tavernier nursery. Those eggs became fertilized and baby corals were born! The corals were raised for a few months in a land-based tank at the Florida Aquarium, and then those same baby corals were returned to our open ocean nursery. Over time cohorts of these 'coral recruits' were returned to the reef and today all of them have been placed back in the wild! To read more about this study click any of the articles below.

CRF™ raises corals from egg to adult and returns them to the wild in collaboration with researcher Joe Henry and the Florida Aquarium. ©Coral Restoration Foundation™

Every summer, CRF™ prepares tirelessly for prospective spawning events both in the nursery and on the reef. Practitioners predict the approximate spawning dates based on past events, water temperatures, and moon cycles. Dive teams at CRF™ then head out to both our nurseries and the reef during the night to observe whether or not genetically mature colonies will spawn.

SEZARC Research Lab Manager Cayman Adams explains cryopreservation during night 2 of spawning season with CRF™. © Coral Restoration Foundation™/South-East Zoological Alliance for Reproduction and Conservation Research

In 2020, members from the South-East Zoo Alliance for Reproduction and Conservation (SEZARC) collaborated with CRF™ to collect gametes from 9 different genotypes in our nursery to be cryopreserved. Cryopreservation is widely regarded as one of the top methods of retaining genetic material of corals. It involves freezing their sperm and egg cells at extremely high temperatures to be later used in the creation of sexual recruits (baby corals) in a lab. To read more about this collaboration click the articles below!

While the CRF team was unfortunately unable to witness spawning in either the reef or the nursery in 2021, we are hopeful that we will gain valuable data and genetic material in 2022! Preparations have already begun with just about 3 months until the due date, we can't wait to see what happens for our corals this year.

CRF™ staghorn corals spawn, releasing thousands of gamete bundles at once. ©Coral Restoration Foundation™


"Talking Science" Editorial Intern

After spending many summers exploring the coasts of the Virginia Barrier Islands on the Chesapeake Bay and along the rocky beaches of Massachusetts’ South Shore, Kendall developed an immense passion for not only the ocean but marine conservation as a whole. She became SCUBA certified in 2013 while on a marine biology summer program that took her to different islands throughout the Caribbean. It was here that she got her first look at the astounding beauty of coral reefs and fully learned about the harsh human-based actions that have led to their demise.

Kendall graduated from the University of California, Los Angeles with a degree in Geography/Environmental Studies and a minor in Geospatial Information Systems & Technologies in 2019. She has conducted field work in Fiji, Australia, and Curaçao with a variety of marine organisms including sharks, whales, and coral. She is extremely excited to intern with CRF and learn more about the conservation of coral reefs while simultaneously spreading their important message through effective and strategic communication.


Coral Chronicles Editor

Madalen Howard is CRF's Communications and Outreach Coordinator. Madalen comes to CRF™ via a winding road from the Tennessee hills, to the South Carolina low country, ending here in Florida’s Coral Reef. She earned her Bachelor's degree in Marine Biology and a Minor in Environmental Studies from the College of Charleston in 2016. Her experience ranges from field research to education, and communications.

Madalen spent the 4 years as a Field Instructor and Social Media Strategist for MarineLab Environmental Education Center. There she was able to study and teach marine ecology, while snorkeling through mangroves, seagrasses, and coral reefs every day. While at MarineLab she combined her education and research background, entered the world of communications, and developed MarineLab’s social media department from the ground up.

Throughout her life Madalen has had a skill connecting people with nature. With CRF™, she is excited to bring people into the world of coral restoration, creating inclusive pathways to scientific discovery.

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