A day in the life of a coral breeder

A carefully controlled water system raises thousands of baby coral fragments in dozens of tanks, called “raceways,” under black billowing tarps beside the Mote Marine Laboratory Summerland Key facility. (Caroline Catherman/Medill)

By Caroline Catherman
Medill Reports

Florida Keys – When I walked into the Mote Marine Laboratory’s Elizabeth Moore International Center for Coral Reef Research & Restoration, I never thought I’d end up siphoning snail poop. 

The private nonprofit breeds coral species in indoor and outdoor tanks for research and out-planting on Florida’s reef, which has lost all but 2% of its coral cover. Mote scientists and trained volunteers have restored over 100,000 corals, and last year, they saw a lab-grown massive coral spawn in the wild for the first time ever, in any lab. This provides hope that Mote’s efforts have created self-sustaining life.

But before they can reproduce or get planted on a reef, Mote’s corals need to grow. 

During that time, someone needs to do the dirty work— in this case, mostly cleaning. I filled in for an intern of Staff Biologist Cody Engelsma, a self-proclaimed “coral farmer” who works on a team that selectively breeds coral varieties to maximize features like disease resistance while maintaining genetic diversity. I found out all the work that goes into caring for these highly endangered species for just a day. 

One side of these houses faces a wildlife refuge, the other side, a canal leading out to the ocean in Big Pine Key. (Caroline Catherman/Medill)

6:30 a.m. For the first time in my life, I’m actually a morning person. I’m staying on Big Pine Key, an island full of colorful houses on flood-proofing stilts. My rental house borders a man-made canal that runs to the Gulf of Mexico. Morning doves land on my neighbor’s boat, beginning to coo. One of Big Pine Key’s infamous Key deer wanders through the yard across from me, munching fallen yellow leaves beneath an oblivious man sipping coffee on his second-story porch.

I don’t need to waste time putting on makeup, bug spray, or even sunscreen. I’ll be working with baby corals, so I’m not allowed to wear any of those.

A Key deer stops in the middle of the road, distracted by an incoming motorist (Caroline Catherman/Medill)

7:30 a.m. I head to Mote on Summerland Key, a 15-minute drive on the Overseas Highway. The road off the island is lined with palmettos and shaded by native plants. I have to stop to dodge the endangered Key deer as I leave the National Key Deer Refuge. These deer were once threatened by habitat loss and poaching, according to the U.S. Fish and Wildlife Service, but now their biggest threat is their indifference to traffic. I swear they wait to cross the road until they see my car coming.

Corals are growing in these tanks in a second-floor lab lit by UV lights, where Engelsma works. (Caroline Catherman/Medill)

8:00 a.m. After crossing four bridges over three islands, I meet Engelsma in a lab on the second floor of Mote’s boxy, concrete, category-5-hurricane-proof building. At the door, I step first on a wet floor mat that says “sanitize,” then a second that says “dry.” 

Tanks of corals are lit by artificial light. Taped on a row of cabinets are goofy names for Staghorn corals that Engelsma and his interns have bequeathed throughout the years: “Shmibuelock” (with two exclamation points), “Chance,” “PollyPolyp” (a coral with clearly extended polyps).

The names reflect Engelsma’s genuine love for the coral. 

“I take pride in my children going out and being out-planted,” he says.

We won’t spend much time in this sterile, air-conditioned lab, though.

Me, siphoning snail poop. (Colleen Shortal/Mote intern)

8:00a.m.-9:30 a.m. The first task of the day is siphoning off the snail poop in the outdoor tanks. 

Engelsma explains that snails eat algae, which makes them a cheap and easy tank cleaner. But they also poop. A lot. And that poop can then pollute the water.

“I didn’t think working here would involve so much cleaning,” says Engelsma’s intern Colleen Shortal with a laugh. She graduated from Michigan State University in 2020 with a B.S. in Zoology and Animal Biology. She’s taken care of falcons, alligators, and possums, all more traditional animals than coral. But she’s grown to love them, and throughout the day, I slowly being to see proof that these aren’t just rocks. 

It is surreal moving corals and stacking their racks on top of each other so I can siphon underneath them. And it really isn’t hard, once I discover a balance between going too slow and sending poop spiraling throughout the tank. But by the end of the hour, my back is sore and my body slippery with sweat. Not to mention, I have to dunk my equipment in a bleach bucket and then spray it with a hose between tanks to avoid spreading disease or bacteria among raceways. Somehow, I always get myself soaked in the process.

Corals retract, showing their polyps. (Caroline Catherman/Medill)

9:30-10:30 a.m. I then go back and, one by one, baste all the baby corals with a small pipette. Blowing them with a pipette mimics ocean currents, explains Engelsma. It also cleans off any excess snail poop and clears a natural layer of mucus. 

Like most of my day, it’s a gentle routine. Move over a centimeter, pinch the baster, repeat. As I blow them, I can actually see the coral move to retract and display polyps (all the small dots on the coral in the picture above). 

Engelsma follows behind me, inspecting each coral for signs of tissue loss, which would be in the form of a white spot on the reddish-brown surface. Even in these carefully controlled saltwater tanks, disease happens occasionally. When it pops up, they’ll give the coral an iodine bath, trying antibiotics, just like humans take, if that doesn’t work. 

Shortal squirts a mixture of fish food and tank water into corals’ mouths with a pipette. (Caroline Catherman/Medill)

10:30-11:30 a.m. Lunchtime! Corals actually produce energy through photosynthesis, so they don’t need to be fed. Not every department feeds their corals every day. But Engelsma and his boss Hanna Koch, a Ph.D. evolutionary biologist, are constantly trying new things to expedite the growing process and raise healthier corals.

We want them to have the best chance possible,” explains Engelsma. “We’re always like ‘how can we get these to grow a little bit faster?’” 

Engelsma is actually helping another organization, DiveN2Life, run an experiment where they feed coral different types of food to see which helps them grow the fastest. Koch mentioned several other experiments that are being run in collaboration with her department.

“There’s still so much we don’t know, and that leaves a lot of room for discovery, and exploration, and creativity,” said Koch in an interview in her office, across a hallway from the lab that Engelsma works in.

Shortal inspects one coral plug. (Caroline Catherman)

11:30-12:00 The final task before lunch for the humans is actually gluing coral onto plugs with waterproof superglue. I am absolutely terrified to touch coral, especially this endangered species, but Engelsma assures me that in a lab setting, it’s okay.

“A coral can handle it once or twice, but if you had every single person doing it, it adds a lot of stress,” he said. “That’s why you see signs like ‘don’t touch the coral!’”

In order to glue the coral onto the plugs, I really have to push hard, often shattering it. I freaked out. Engelsma told me that was fine. This was nothing compared to what we did later. 

Lunchtime view. (Caroline Catherman)

12:00-1:00 p.m. Most of the staff eats lunch at picnic tables overlooking the water at noon. 

Engelsma and his intern eat at the same time and place every day, but other staff schedules vary widely. Due to the heavy load of work, many can’t stick to a consistent lunch schedule. But today, I eat at picnic tables with about a dozen other staff members and get to appreciate this view.

Shortal frags a coral. (Caroline Catherman)

1:00-2:30 The final big task of the day for me is fragging. Many of the coral on the plugs outside is created by fragging (cutting) larger pieces of coral into smaller pieces with a vibrating blade mixed with diamonds. 

Coral can’t feel pain, and this process doesn’t kill them. This is a type of asexual reproduction that might happen naturally if a predator nibbles off some coral and drops it, for instance. It’s similar to propagating a plant. 

Mote scientists have been able to use fragging as a tool to speed up growth. Mote’s website states that fragging helps corals grow up to 50 times faster. 

So while it may seem messy, the only animals harmed by this process are the staff that occasionally cut themselves on the blade.

Engelsma frags. (Caroline Catherman)

“I’m cutting up all my children!” says Engelsma with a laugh as he slices a full plug of coral into eight pieces.

Engelsma is cutting up one of his favorite children today, a genotype of Orbicella faveolata, also known as mountainous star coral. The species is hard to keep alive. This was one of less than ten survivors from 2019’s spawning of over 30,000. And this guy had the most colorful bright green polyps of the bunch.

A year and a half later, his one favorite is finally big enough to frag. Now it has been transformed into nine favorites.

A sunset view over the Gulf of Mexico. (Caroline Catherman)

After fragging, I clean up and head out of the lab by about 3:00 pm. Engelsma stays a little later, finishing up a presentation. I’m left to write and explore the island, though I always end up on a bike ride at around 8 p.m., watching the sunset over the Gulf of Mexico. 

I didn’t know it at the time, but this day of work was only one small fraction of all the research and husbandry that goes on in Mote’s many different departments, and absolutely nothing compared to the frantic work that happens in August, when the sexually mature corals in the lab will spawn. 

“It’s just like being a real parent, I guess,” Koch said. “It’s really rewarding, but it’s a daily job.” 

And just like a real parent, Koch continues to visit her corals after they leave home, when they are planted on the reef, to see if they’re having kids of their own. But Koch, Engelsma, and everyone else at Mote have a wild dream–one some worry isn’t even realistic–that one day, decades from now, Florida’s reef can be restored to the point that they don’t have to check in with their “children,” that they just know they’re okay, and will reproduce on their own.

The goal, they both told me, is “to put ourselves out of a job.” 

Caroline Catherman covers health, environment, and science at Medill. You can follow her on Twitter at @CECatherman.