Environment

How scientists are saving Florida's endangered coral reefs from extreme heat

WUSF | By Steve Newborn

Published July 24, 2023 at 3:07 PM EDT

In the past week, the University of South Florida's Florida Institute of Oceanography’s Keys Marine Laboratory (KML) has transferred 1,500 coral specimens from offshore nurseries to onshore tanks.

Their laboratory has 60 tanks ranging from 40 to 1,000 gallons. They can house thousands more as the coral bleaching event is expected to continue.

“For years we have been developing the infrastructure capacity to support reef restoration efforts that enable KML to temporarily house corals during emergencies such as this,” said laboratory director Cynthia Lewis. “Typically, water temperatures at this time of year are in the mid 80s, but we are already recording temperatures of 90 degrees. It is very alarming.”

Keri O'Neil is the senior coral specialist at the Florida Aquarium, which is partnering with the laboratory. She just came back from a trip to the Florida Keys, and tells WUSF's Steve Newborn about some of the new ways scientists are working to make sure Florida's coral reefs last long into the future.

So tell me your impressions on what's going on the Florida Keys. I've heard the water is as high as 98 degrees.

On the Florida Bay side of the Florida Keys, the water has been in the mid to upper 90s. And then on the reef side, the water has really been anywhere from our sort of normal seasonal temperature of 85, 86, up to maybe even 91 and 92 on some reef sites.

So what does this mean for the coral? It's really early in the year for the temperature to be spiking this high. Has it created added stressors for them?

So we officially reached what the NOAA Coral Reef Watch program calls Alert Level Two for coral bleaching, which is the highest level. And we've been at that level, historically, sometimes in August. But this is the first time we've reached that level in July. So that basically means we still have many more weeks of potentially hot water to come.

We are hoping that we can make corals more resistant to these types of heat events. However, this one is very extreme, we didn't expect it to kind of be tested this early. This work can take decades to really get to this level of an outcome.

Keri O'Neil

I've been reading about programs that are trying to isolate corals that are less susceptible to heat.

So there's a lot of different groups, you know, ourselves included, that are interested in trying to make corals more heat resistant in various ways. And that might be through breeding parents that are more heat resistant, or trying to actually manipulate the algae that lives inside the coral, to use more heat-resistant algae. So right now, it's interesting, because some corals will make it through this event. So we really are watching very closely to what's happening to the corals in the ocean and seeing which corals do survive this event. And that gives us really good information for our future work as to what corals might make the best parents to breed in the future.

And we are hoping that we can make corals more resistant to these types of heat events. However, this one is very extreme, we didn't expect it to kind of be tested this early. This work can take decades to really get to this level of an outcome. We didn't realize we'd be dealing with temperatures this hot this quickly.

Well, we don't have decades, obviously. So is there anything you can do to speed up the process? Or is this something that you have to let science take its course?

You do somewhat have to let science take its course. And that's the big problem here is that scientists might not have enough time to really figure out how to breed a better coral before it is too late. But, Florida has risks of seeing major bleaching events in the past. And just because bleaching happens doesn't mean the coral will die. So we still have to keep a very close eye on what's happening on our reef.

And you'll see a variety of stories coming out about people now moving corals onto land. Even some of our partners that have ocean-based coral nurseries are trying to move some of those stocks into temperature-controlled tanks on land and various locations to kind of get them through the summer. So we make sure we don't lose our parent stock. We can always breed them more in the future and fragment them more in the future. But right now, it's mostly about safeguarding our sort of existing parent stocks so that we all are able to do more work in the future.

It seems like there's been a lot of research on this in the last few years. Do you feel hopeful that we can find some kind of status quo for the corals and make sure that our children and grandchildren will be able to enjoy them as well?

Yeah, I think there's two things that need to happen. The scientists need to continue working towards better restoration work and better breeding, and maybe even some more extreme interventions like bringing in corals from other regions and crossing them with our Florida population. But the other thing that just really needs to happen is, you know, global change in the way that we are treating our climate and reducing carbon dioxide emissions and just really getting serious about trying to limit the rising temperature in our planet.