By Georgia Jackson, College of Arts and Sciences
John Parkinson, an assistant professor in the Department of Integrative Biology at the University of South Florida, has long advocated for the need to test and implement new approaches to retain ecosystem function among coral reefs and prevent species loss.
In early 2023, he set up an experiment off the Florida coast to determine how well coral fragments native to the northern end of Florida’s Coral Reef — which stretches almost 350 miles from the St. Lucie Inlet down to the Dry Tortugas — would fair when transplanted to the warmer waters of the southern end.
The experiment was part of a larger effort to understand the genetic basis of heat tolerance in corals and to try and determine whether thermal tolerance in corals can be predicted using molecular tools, like DNA analysis.
“It’s the same thing 23andMe is based on,” said Parkinson, who heads the Parkinson Lab at USF. “If you know which versions of genes you have, you can predict whether you're more or less likely to get breast cancer, for example. That's associating a disease phenotype with genetic variation. We are trying to associate heat tolerance phenotypes with genetic variation because if we could do that, then we could identify which corals might survive in a warmer ocean and use them for restoration.”
Two weeks after Parkinson transplanted the coral fragments, the marine heat wave of 2023 devastated Florida’s Coral Reef — the only living barrier reef in the continental U.S. Where 150 genetically distinct elkhorn coral once lived, only 23 remain.
The marine heatwave contributed to the fourth and largest global coral bleaching event to date, according to the National Oceanic and Atmospheric Administration (NOAA), surpassing the event that occurred between 2014 and 2017 and impacted more than 68 percent of the world’s reef area.
“These days, it seems we can't even run experiments to their conclusion,” Parkinson said. “It used to be that you could.”
TURNING RESEARCH INTO POLICY
Despite setbacks, Parkinson and his team of student researchers are committed to bringing Florida’s Coral Reef — and others like it around the world — back from the brink of collapse. In the Parkinson Lab at the University of South Florida, they conduct aquarium-based experiments using fragments of the same corals they planned to study in the field.
More than anything, the increasing frequency and intensity of global coral bleaching events has accelerated the need for data-driven restoration solutions like the ones for which Parkinson is an advocate.
Parkinson and graduate student Matt Gamache apply genomic techniques to assess the genetic basis of heat tolerance in corals. [Photo by Corey Lepak]
“It's gone from being the occasional problem to a consistent problem every year,” said Parkinson, who has been scuba diving on reefs for over two decades. “And then there's this issue of shifting baselines. What I started out thinking was a healthy reef would have been considered unimpressive to those diving decades earlier. I feel awful for my students, who didn’t even get to see what I did.
“It’s amazing how rapidly the degradation has accelerated.”
Some of the most diverse ecosystems on Earth, coral reefs are home to more than a quarter of all marine life, according to NOAA, and provide food to both coastal and inland communities. Reefs also reduce the impact of storms and floods, play a key role in the development of new medicines and support tourism in coastal economies.
“If we do nothing and the corals disappear, we lose the fish, we lose the coastal protection, we lose the tourism and we lose the bioprospecting potential,” said Parkinson, who is part of the Coral Restoration Consortium’s Genetics Working Group. “Some of our most effective drugs have come from coral reef ecosystems.”
Parkinson made a case for implementing a new approach called assisted gene flow to prevent species loss and retain ecosystem function in a recent article published by “Science,” one of the world’s leading academic journals.
“I don't think corals are going to go completely extinct,” Parkinson said. “We'll have patches of corals even if it keeps getting warmer. But they won't necessarily be generating the reefs or the ecological goods and services that we're used to without intervention."
Parkinson and PhD candidate Matz Indergard exposed corals in the Parkinson Lab to heat stress to determine what impact it would have on the sample [Photo by Corey Lepak]
If implemented, assisted gene flow would facilitate immediate breeding efforts by propagating colonies.
“It’s a very simple equation,” Parkinson said. “Corals spawn one night per year. If you have a bunch of corals together, you get a lot of babies. If you have a few corals and they're spread apart, their gametes don't even reach each other and you're not producing any babies. And then that year's reproductive effort is wasted.
“That's what's been happening in Florida over the past few decades,” Parkinson said. “As the population gets smaller and smaller, it's harder and harder for it to recover, which is why assisted gene flow is an idea I think people can get behind. We’re really just taking a natural process and facilitating it.”
The goal for Parkinson and others in the Coral Restoration Consortium’s Genetics Working Group is to return coral reef communities to a state of self-sufficiency.
“The less that we are involved in this whole process, the better,” Parkinson said. “Let nature do its thing. But the situation for staghorn corals is as dire as it was for the Florida panther. We’re at the point where if you don't do anything, you're going to lose the last remaining individuals in the Florida Keys. So, let's bring in more colonies from outside and let them breed — while also trying to fix water quality issues and reduce greenhouse gas emissions.”
Assisted gene flow was recently approved by the Florida Fish and Wildlife Conservation Commission to help save elkhorn corals in Florida by crossing elkhorn coral parents from Florida with others from Honduras.
Parkinson is hopeful the technique will be applied to reefs in the wider Caribbean, where corals are in chronic decline.
OVERCOMING OBSTACLES
The biggest obstacle to implementing new approaches like assisted gene flow, according to Parkinson, is rigid adherence to the precautionary principle, which requires practitioners to prove not only the benefits of their proposed approach but also that it would cause no additional harm.
“I understand these arguments that say, ‘You know, we brought different species to Australia and look at the damage we did there.’ And that's why we're not really advocating for extreme manipulation,” Parkinson said. “We’re focusing on a species that we also find throughout the rest of the Caribbean. The genetics are telling us that it’s one big population. We should be able to take colonies from one place and move them to another without too many negative consequences.
“I feel the risks of doing nothing are far worse.”
Learn more about Parkinson Lab and coral restoration research at the University of South Florida.