- Florida’s coral reef sits at 98% decline — only 2% of healthy coral cover remains.
- Jessica Levy of Coral Restoration Foundation walks us through restoring this vital ecosystem.
- The process involves attaching corals to a “coral tree,” which allows them to grow safely.
Following is a transcript of the video.
Jessica Levy: The Florida reef tract is the US’s only barrier reef system. It’s about 300 miles long. And what we saw over the last few decades is an incredible decline in coral cover. What we’re looking at is the potential loss of an entire ecosystem, which we’ve never experienced in human history, and I don’t think anyone wants to find out what that would mean if we had a complete collapse of our coral reef ecosystems.
My name is Jessica Levy, and I am the Director of Restoration Strategy for the Coral Restoration Foundation. The Coral Restoration Foundation is a non-for-profit headquartered in the Florida Keys.
So here we are in one of Coral Restoration Foundation’s offshore coral nurseries. It’s about an acre and a half wide. It’s the largest offshore coral nursery in the world, and it’s a spectacular site to visit.
The restoration process starts in the very original sense with collections of natural corals. These are corals that are at risk to some event, so we actually go out to our local reefs and harvest from them.
And instead of return visits to the wild, we use that coral in a nursery system where that original collection is allowed to grow over time. And as it grows, you take subsequent cuttings from that original collection and you produce more and more corals.
The main structure that CRF uses and pioneered is what’s known as the coral tree. It’s a very simple structure that floats in the water column. It’s made of PVC and fiberglass. In our nurseries in particular, we have upwards of 500 of these coral structures, and the corals are actually suspended on those structures themselves.
So you’ll see our divers swimming through this forest of coral trees. Some of the main activities that they’re likely to do in a nursery is cleaning, removing algae and biofouls, and any other organisms that have kind of grown on those structures and might compete with that coral for living space.
We use very simple materials to work on our trees. We use wire brushes or a chisel to clean the structures themselves. We use clippers to actually cut the coral, or cut the monofilament line that the coral is suspended from the tree with. While you can work pretty heavy-handed with the trees themselves, corals are a living animal, it’s a very thin layer of animal tissue, so we’re very gentle when we’re working with the coral itself.
Typically when we suspend a coral fragment, it’s maybe a couple of centimeters long or wide. And then after about nine months it’ll grow to about the size of a football at which point that is an appropriate size, what we call reef-ready, and able to be moved to a nearby restoration site.
We will go to a structure, go to a coral tree and clip from those individual corals there. This takes advantage of a process known as asexual fragmentation, essentially making clones of your original, your individual. And we fragment from the corals on the trees, we’ll move them to either new trees and resuspend them to continue to grow, and take advantage of that nursery phase, or we’ll fragment from the existing stock and go through a process of harvesting.
So we’ll go to these trees themselves and we’ll actually collect corals from those nurseries. Those corals are then moved onto our boats, and they sit in seawater, and then they’ll be transported to a nearby restoration site to begin the process of outplanting.
Once we’re at an outplant site, our divers enter the water. Someone from the boat hands them crates of corals. Those divers then swim down. Once we’re at the reef, the first step in the process is to find your outplant site. So this is an area that’s relatively hard bottom, open, lots of space and available substrate to work with.
A diver then clears the reef area where that coral is going to eventually be secured. What we look for is white, crisp rock. It’s basically limestone or old coral. We then mix our two part epoxy in this almost like pulling taffy motion until it’s one single clay or putty. We’ll take a small pinch of that epoxy that we’ve just mixed, push that into the reef substrate itself and then gently place the coral on top of that point that we’ve cleared, and that epoxy will harden and have attached that coral to the reef itself.
We’ll then pretty much step and repeat the process until an individual diver has gotten 100 corals down, or until a team of divers has gotten anywhere from 300-800 corals done in a single day.
These corals are placed in clusters of about 50-70 individuals. They’re placed in clusters of the same genetic material. So they’re essentially clones of their neighbors. Over time, these corals start to branch out and they start to touch their neighbors, and they start to fuse. And what happens is they create this one large thicket. So this thicket has all these in and outs that allow small fish to duck in and hide from predators. It allows for a lot of inverts to thrive there as well. This is the structure that we really want to produce. The important part is promoting that genetic diversity on the reef site. Our nursery program on an annual basis produces probably about 40,000 reef-ready corals.
The reality is, is restoration is never a one-off. It’s not something you do and then pretty much ever walk away from. There probably will always be work to do. And the reason is, is it’s because we have not removed all the pressures and the stress that our reefs face today. And until we fully remove all these pressures, we’re still going to have the need for restoration.
Restoration right now kind of works to keep pace with that loss, to keep pace with an ecosystem still kind of going, even if it’s maybe considered to be treading water. It’s still about keeping the system alive, because if we don’t do anything now, there’s not gonna be anything left to work with.
This is not just a Florida problem, reefs around the world are facing the exact same challenges and scale of decline. In the last 30 years, global coral reefs have declined by 50%. This has a cascading effect on a lot of different aspects. For example, 25% of marine life depends on a coral reef system at some point in their life history, whether they live there full time or they migrate to at some point in their life cycle.
Additionally, coral reefs are a part of a healthy ocean system. About 70% of the oxygen that we, as humans breathe comes from our oceans. Florida, in particular, sits at about 98% decline, which means about 2% coral cover left. Which, although drastic and terrible, it’s better than zero. We don’t want to find out what happens when we hit zero.
It’s easy to talk about the impact of a degraded coral reef to a local community. That has a very 1-1 connection. The reality is, it affects all of us, whether you live on a coastline or you live somewhere where you’ve never even seen the ocean to begin with.