APOLLO BEACH, Florida – The Florida Aquarium has taken another major milestone in its mission to restore coral reefs through crossbreeding and cryopreservation.
Scientists have bred grooved brain corals collected near Fort Lauderdale and matured in the lab, with wild samples coming from waters further south.
The result? A handful of golden brown coral babies, living on small ceramic tiles on the aquarium’s Apollo Beach campus.
“Small miracles,” said Emily Williams, biologist for the coral conservation team.
The successful breeding effort created offspring with greater genetic diversity and greater resistance to disease than those that inhabit Florida’s Atlantic coast, scientists say. This means they might be better equipped to withstand the threats ravaging the world’s third largest reef, including climate change and ocean acidification.
Stony tissue coral disease also entered Florida reefs in 2014, wiping out vast swathes of 20 species of coral.
“The more genetic diversity the corals have, the more likely they are to fight threats and change,” said senior biologist Rachel Serafin.
Baby cross corals grow in a golden brown color on rectangular ceramic tiles.
In the ideal future, devastated ecosystems could be reconstructed with these stronger, laboratory samples. Red and orange corals that first smelled of water in a reservoir could repopulate the waters off Martin County south of the Florida Keys.
“Our end goal is to get us out of work,” said Williams. “To restore corals to their former glory where they are happy and healthy and thrive without us.”
Florida Aquarium researchers have been working in this direction for years. They coaxed endangered coral in the Atlantic Ocean to spawn in a lab in late 2019. Streaked cactus coral followed closely, in April 2020.
But this May marked the first time that Florida conservatives have used frozen, preserved semen to replicate samples taken from miles away, at different times.
The Florida Aquarium recovered the coast of Fort Lauderdale for healthy, grooved brain corals to save them from stony tissue coral disease in the spring of 2018 and 2019. As part of the Florida Coral Rescue Project, the researchers threw animals out of vulnerable waters and rescued colonies spawned under human care.
Williams stored milliliters of the resulting semen in liquid nitrogen and a substance that freezes tissue, indefinitely.
Across the Sunshine State last month, scientists at UM initiated a similar process: collecting and cryopreserving sperm from wild brain corals off Key Largo. Then the two institutions exchanged samples.
Watching the coral’s reproductive process was like seeing “a living snow globe with little clumps, floating on the surface,” Williams said. “As these packets broke, the water became cloudy and hazy with the semen.”
Two days later, the coral larvae from the mixtures began to metamorphose into baby corals in the Florida Aquarium lab. The same was happening in Miami. Both institutions had bred cross offspring.
It’s an impressive feat, almost impossible of course, said Andrew Baker, professor of marine biology at UM.
The two brain coral specimens used in the effort are otherwise unlikely to be found, due to the distance between their oceanic homes. It is only in the laboratory that animals can be brought together to reproduce.
“It’s an encouraging sign that while there are all of these horrible dangers to corals, there are things science can do,” Baker said.
A single pair of brain corals can produce thousands of offspring each year. When reared in a controlled laboratory, survival can reach 50%, compared to less than 1% in the wild.
Now, researchers are looking to the lives of the new crossbreed baby corals.
The Florida Aquarium placed the babies on non-toxic tiles, in shallow pools with circulating salt water. Animals will be shaded and sheltered until maturity, or until curators determine an alternate next step.
They hope that the animals can one day be released into the Atlantic, to thrive and reproduce independently.
Reefs could be saved by these breeding efforts, strengthening the species. Recent findings in Florida have been shared with coral conservation advocates around the world, who are keen to repair vulnerable comparable coral ecosystems in Australia, South America and beyond.
Losing corals is not an option for the oceans, Serafin said.
“Coral restoration increasingly relies on sexual reproduction and selective breeding,” Baker added. “We cannot wait for nature to correct the balance and repopulate the reefs. We must act now. Extinction is forever. (C) 2021 Tampa Bay Times. Visit tampabay.com. Distributed by Tribune Content Agency, LLC.