For the first time, massive corals restored to Florida’s Coral Reef are ready to become parents in the wild — a breakthrough in Mote Marine Laboratory’s scientific efforts to restore critically imperiled coral reefs, the “rainforests of the sea,” to self-sustaining life. This month, Mote’s coral reproduction scientist, Dr. Hanna Koch, identified gametes (eggs and sperm) inside colonies of two threatened, yet key, reef-building species that Mote restored to Florida Keys reefs in recent years: the massive or mounding species called mountainous star coral (Orbicella faveolata) and branching staghorn coral (Acropora cervicornis). Both species are listed as Threatened under the Endangered Species Act. The presence of gametes indicates that these corals are sexually mature, gravid (pregnant), and ready to produce the next generation of coral “babies” with fresh genetics to help revive declining coral populations.
These corals are achieving critical milestones for the entire field of coral reef restoration—showing the first signs that they are capable of producing new generations of corals on their own. These and other corals in Mote’s restored populations survived big challenges to reach this point, demonstrating resilience. Their success validates the significance and progress of Mote’s science-based, resilience-focused coral restoration.
An exciting first: The mountainous star coral (O. faveolata) colonies, which Mote outplanted in 2015 off of Cook Island near Big Pine Key, are the first corals of any massive or mounding species that have been documented to produce gametes (i.e., be sexually mature) after being restored in Florida or Caribbean waters. Sexual maturity is size-dependent in stony corals; slow-growing massive species like mountainous star coral—which tends to grow less than 1 centimeter per year—can take decades to grow from “baby” size to sexually mature size. However, using the propagation and outplanting methodology that Mote pioneered, which is called “microfragmentation-fusion” or “reskinning,” larger colonies of corals can be generated faster. Instead of decades, Mote can now produce sexually mature mountainous star corals in as little as five years.
“The ability to produce sexually mature colonies of the most important frame-building corals in the Florida Keys in such a short time frame is a major scientific breakthrough,” said Dr. Andrew Bruckner, Research Coordinator at the Florida Keys National Marine Sanctuary. “This is a huge boost for our restoration efforts as these corals provide critical ecosystem services and ecological benefits for associated species on the restored reefs, while indirectly accelerating the recovery of Florida’s reef ecosystem through the production of offspring that can colonize surrounding reefs.”
Another reason to celebrate: The staghorn coral (A. cervicornis) colonies, outplanted in 2016, 2017 and 2018 at Eastern Dry Rocks off of Key West, are the first Mote-planted staghorn corals observed to reach sexual maturity after being restored to the reef, demonstrating that staghorn outplants can reach this critical milestone within as little as two years, an observation that has been cited only once before.
What this means: Mote’s science-based coral restoration strategy—combining resilience testing and multiple growth/reproductive interventions—is proving to be highly successful!
Coral spawning research planned: Multiple Florida coral species spawn (synchronously release sperm and eggs, leading to fertilization and new coral babies) after the August full moon. This August, Dr. Hanna Koch, accompanied by other Mote scientists and interns, is leading three field research efforts focused on spawning: documenting spawning activity from the restored mountainous star coral (O. faveolata) near Big Pine Key and restored staghorn coral (A. cervicornis) near Key West, while collecting sperm and eggs from elkhorn coral (Acropora palmata) at Looe Key for reproduction events back at Mote’s Summerland Key campus.
Learn more about Mote Marine at www.mote.org.