Colonies of coral have spawned in breakthrough restoration
STAFF REPORT- For the first time in Florida or Caribbean waters, restored massive corals were observed spawning – part of sexual reproduction that could result in the next generation of coral offspring – thanks to Mote Marine Laboratory & Aquarium’s innovative efforts to restore Florida’s Coral Reef.
Over the past few nights, Mote coral scientists observed restored colonies of mountainous star coral (Orbicella faveolata) on a reef near Cook Island, hoping to capture the brief moment during the evening where the coral release their gametes (eggs and sperm) into the water column, a process known as spawning. On August 9, to the delight of Mote scientists, a coral colony known to be gravid (containing gametes) released its gametes in an extraordinary display. Further cause for underwater celebration came on August 10, when five more colonies spawned. This is the first time that restored massive corals have been documented to spawn on Florida’s Coral Reef.
These colonies were restored to the reef as small microfragments in 2015 as part of Mote’s science-based restoration strategy. Read the story announcing that several of these colonies were identified to be gravid here.
The documentation of the presence of gametes and of spawning in colonies of restored mountainous star coral is a first for massive corals in Florida and the Caribbean. This key species is listed as threatened under the U.S. Endangered Species Act, and is one of the most critical reef-builders on Florida’s Reef Tract, helping to form the backbone of the entire reef system.
Corals reach sexual maturity not at a certain age, but a certain size. Growing at less than 1 centimeter per year, mountainous star coral might take decades to reach sexual maturity. Through the Mote-pioneered methodology of microfragmentation-fusion, these slow-growing corals can have their growth process sped up significantly, with these corals reaching sexual maturity in just five years.
Mote’s science-based coral restoration strategy not only creates viable colonies of coral at an accelerated rate, but also concentrates on genetic varieties (genotypes) of corals that are resistant to common stressors found in the ocean environment. These mountainous star coral colonies have endured a global bleaching event in 2015, a Category-4 hurricane (Irma) in 2017, and the 2019 outbreak at this site of stony coral tissue loss disease, which has affected millions of reef corals across Florida’s Coral Reef and beyond.
n Above left, gametes about to be released from the coral.
Credit Dr. Hanna Koch / Mote Marine Laboratory
Below, a restored colony of mountainous star coral releases gametes into the water column. Credit Joe Berg