Spring 2024 Issue:

A Dive
into Coral

Brian Reckenbeil ’09 is committed to the restoration of Florida’s declining coral reef, a biological masterpiece that supports more than 6,000 marine species, protects the state’s coastline, and underlies important sectors of the economy.

By Anndee Hochman, Photos by The Florida Aquarium, Spring 2024

Some people look at a coral reef as an appealing place to go diving, fishing, or snorkeling. Or as a large-scale, real-life version of the toy on the floor of their fish tank. Or perhaps they just see a pretty, colorful, inert rock.

Brian Reckenbeil ’09 sees a fragile, fascinating keystone species at risk.

And his dream job, as coral restoration manager in the Florida Aquarium’s Coral Conservation Program, involves learning as much as he can about how coral reproduces, what endangers it, and how humans can help it thrive.

Florida’s Coral Reef, the only coral reef system in the continental United States, sprawls 360 miles south from the St. Lucie inlet past the Keys to Dry Tortugas National Park. The reef is home to 50 different species of hard corals: some humped and ridged like human brains, some branched as the antlers of an elk.

Corals matter because they are one of the most biodiverse marine environments on the planet, supporting 25 percent of marine life,” says Reckenbeil. “They’re like the rainforest of the sea; with no corals, there is no coral reef or home for its thousands of inhabitants.”

—Brian Reckenbeil ’09

“Corals matter because they are one of the most biodiverse marine environments on the planet, supporting 25 percent of marine life,” says Reckenbeil. “They’re like the rainforest of the sea; with no corals, there is no coral reef or home for its thousands of inhabitants.”

This, in turn, is what makes coral reefs such popular vacation destinations for fishing, diving, or snorkeling.

In Florida, vacation spending helps support a vibrant economy. As does commercial fishing. The Florida spiny lobster, which hides under coral heads, and the stone crab are heavily fished commercially. Each year, more than 60,000 jobs and over $6 billion of the local economy depend on the health of the coral reef in southeast Florida.

The reef’s value, Reckenbeil adds, isn’t only to nourish wildlife like sea sponges, fish, and lobsters—not to mention their higher-on-the-ocean-food-chain relatives like sea turtles, dolphins, and octopuses. Coral ecosystems are a source of important medicines. Anticancer drugs are derived from certain marine algae; the mucus of cone snails contains a potent painkiller; and researchers are exploring the potential of a deep-sea sponge, which attaches to coral, to yield a treatment for pancreatic cancer. Coral reefs also protect coastlines from storm-tossed seas.

A Dive into Coral Research

Acropora palmata (elkhorn coral)

Climate change threatens Florida’s Coral Reef.

Corals are animals, thriving in symbiotic partnership with microscopic algae called zooxanthellae, which give stony corals their vivid colors. Corals gobble the sugars those algae produce through photosynthesis; in turn, the corals’ living tissue gives the algae a safe refuge.

Rising ocean temperatures throw that balance out of whack, Reckenbeil says. When the water is too warm—higher than the mid-80s—for too long, corals expel the algae from their cells and turn a bleachy white, a process the coral community calls coral bleaching. If corals do not recover zooxanthellae into their tissue within two to three weeks, they eventually die.

At the same time, ferocious hurricanes—themselves fueled by swelling ocean and air temperatures—along with sea-level rise that brings on higher waves and greater water mass can damage or destroy the coral reef.

“Corals build reefs that help reduce waves coming to shore,” Reckenbeil explains. “If storms become more and more frequent, the waves eventually knock corals over, an effect we call reef erosion, or flattening of the reef,” says Reckenbeil. “I’ve seen corals 10 to 12 feet across flipped upside-down like cars under water.” With a flattening reef, stronger waves will eventually inundate south Florida’s coastlines.

Unfortunately, Reckenbeil notes, the “out of sight mindset” is all too common to both tourists and even some long-term locals who do not physically see first-hand how the environment is changing.

In 2014, marine biologists began noting a new threat—stony coral tissue loss disease, which can kill decades-old coral colonies in a matter of months. In 2017, Reckenbeil and his team witnessed some disease-ravaged coral in the middle of the Florida Keys. “Half of the brain corals were completely white—not bleached white but recent-tissue-loss white,” he recalls. He wept into his scuba mask. “Why are some coral colonies not affected by this disease? What natural defense do some colonies have versus others?” are questions that popped into Reckenbeil’s head.

A Dive into Coral Research

Brian Reckenbeil ’09 (left) chats with colleague Bryan Danson about the 250 grooved brain corals set aside awaiting a coral health inspection and delivery to the University of Miami. Stony corals require a coral health inspection by an approved veterinarian before they are returned to the ocean.

The job of Reckenbeil and his team isn’t to “save” the reef; he eschews that word as grandiose and arrogant. Their role is a combination of fertility specialist and marine biological researcher; they grow baby corals in the lab and learn what helps them survive.

“The Florida Aquarium’s Coral Conservation Program is a land-based coral nursery,” he says, one that last spawning season created more than 2 million larvae each of which is genetically distinct. The larvae settle and grow on 1-inch tiles in conditions that mimic what they would experience in the ocean.

It’s tricky work, because coral spawns just once a year, following the lunar cycle. While each species has different patterns, most species release their gametes within an hour or two of sunset and a few days after a full moon. But these trends hold true from year to year, so researchers can estimate which nights spawning will occur for each species. Some corals produce eggs only, others release sperm, and still others produce bundles that include both eggs and sperm.

Researchers dilute the sperm, rinse the eggs, and put them in separate containers; then they fertilize the eggs for maximum genetic diversity—for instance, eggs from colony 1 with sperm from colonies 2, 3, 4, and 5.

The fertilized eggs resemble small, tan dots at first; then they develop cilia and begin to move around, hunting for a “reef” to call home. In the lab, that would be the tiles. The goal is to eventually plant them on the reef—Reckenbeil’s team did so in 2022 and 2023—with the hope that they will not just survive but spawn naturally on their own.

“The idea,” he says, “is getting corals to a point where they are not going to need our help.”

A Dive into Coral Research

Brian Reckenbeil ’09 records data about observations on several adult elkhorn coral colonies. The LED lights are set on a schedule to mimic sunlight and moonlight conditions seen in Key Largo, Florida. Corals use these light patterns as signals to know when it is time to spawn.

It’s not the work Reckenbeil envisioned as a boy growing up in Branchburg, New Jersey, where the most interesting aquatic animal was a crayfish. He fantasized about being a professional ice hockey player—never mind that his parents didn’t allow him to try the sport. He also loved playing outdoors and binge-watching Animal Planet episodes; he thought he might enjoy marine biology.

At Moravian, while other guys had sports or beer posters on their dormitory walls, Reckenbeil had images of underwater wildlife. He played football and lacrosse, ignoring the latter team’s library study hours and preferring to study with other environmental science students in a sunny lounge with a blackboard to scribble notes, near the office of then biology professor Diane White Husic.

Husic remembers Reckenbeil as a fun-loving athlete transformed by a semester abroad in Bonaire, an island in the Dutch Caribbean. Reckenbeil calls it “the best six months of my life.” He lived, worked, and studied in a stunning ecosystem—coral reefs more vibrant and healthier than any he’d seen on family snorkeling trips.

I thought, ‘I want people to see this environment in the future.’ It made me want to get into restoration. Living, diving, going to class on the reef: I want to do this for my whole life.”

—Brian Reckenbeil ’09

“I thought, ‘I want people to see this environment in the future.’ It made me want to get into restoration. Living, diving, going to class on the reef: I want to do this for my whole life.”

Husic, who taught Reckenbeil in a senior capstone seminar after his return from Bonaire, remembers noting a new passion in his research project on sea grasses and their importance in marine conservation. “What amazed me was the depth of understanding he had and the quality of the presentation he gave. This was top-notch work.”

For Reckenbeil, the pieces of his education and field work were starting to fuse. There was the genetics class—he wasn’t a star student, but he did check diligently on his colony of fruit flies every 8 to 12 hours, after breakfast or before football practice and again before bed—when he realized that science could involve hands-on research and inquiry.

There was his first scuba dive, during a 19-day trip to Ecuador and the Galapagos Islands that was part of a junior-year May term class. Before that, he’d had two practice scuba dives in a pool. In the chilly waters of the Galapagos, “We woke up super-early. They got us into thick wetsuits and showed us the basics. We saw some big sharks, some rays. It was spectacular.” Then came the semester in Bonaire.

Those experiences spurred Reckenbeil toward graduate school—a master’s in natural resources at Delaware State University, where he worked on oyster reef restoration—and ultimately to his current position at the Florida Aquarium.

Reckenbeil says his undergraduate years schooled him well for the time-management demands of his work. “As a biology student, I had three-hour labs in addition to classes Monday through Friday and football practice and games.”

Athletics also taught him to thrive in a team setting; a favorite aspect of his current job is to guide others who have less underwater experience. “Teaching them some of the skills I’ve learned in the field over the past eight years and seeing the joy of other staff members have been impactful, especially as they now get to help in a corals graduation ceremony, going from the lab to the reef.”

A Dive into Coral Research

In the Florida Aquarium, Brian Reckenbeil ’09 poses with Acropora cervicornis (branching corals) that were spawned, born, and settled at the aquarium.

The impact of his team’s work on the coral reef depends on what you measure. To some, he says, success might mean a high survival rate of the lab-grown coral they outplant, or finding reef sites that experience less coral predation than others do. And Reckenbeil notes that even the failures are opportunities to learn which genetic or environmental factors make some corals hardier than others. That learning may be key to repopulating a dying reef with corals that have a future.

In June 2023, Reckenbeil and his colleagues outplanted three species of lab-born and -raised boulder coral off the middle Florida Keys. This past summer, Florida experienced its hottest summer on record, with 22 weeks above the bleaching threshold limit. When Reckenbeil and his team returned to these sites in early December 2023 after this unprecedented marine heat wave, they expected all 700+ newly outplanted colonies to be dead, due to bleaching caused by the extreme heat. To their surprise, while they have not yet processed their photos and data, they estimate survival to be between 60 and 90 percent at their six outplant locations.

I was the first diver off the boat on this trip, and when I saw the corals alive, I turned around and started to dance and cheer underwater.”

—Brian Reckenbeil ’09

There was no cheering at the 2019 branching coral outplant site. “In June 2023, we saw dozens of outplanted live healthy colonies that roughly had grown from the size of a pencil to that of a basketball in four years. In July, we filmed with Good Morning America, and 100 percent of those branching corals we had seen just three weeks earlier were bleached, dying, or dead. As of December 2023, all colonies were confirmed dead, due to bleaching.”

What Reckenbeil and his team learned was that even though the best management practices generally suggest not to outplant corals during summer months, that guideline may be dependent on species, site, or temperature.

“It’s hard to talk about declining coral reefs without getting a little depressed,” Reckenbeil says. “Everyone wants to give a positive message—everything’s going to be okay—but sometimes, in the back of your head, you think, realistically, it’s a very challenging ecosystem to help restore.”

“We’re putting corals out there that are the size of a quarter. They grow so slowly, as it typically takes one to two years for a boulder coral to reach this size. The amount of coral we can grow in one year is a drop in the bucket, a pinprick on the map compared to what we are losing.” He tries to focus not on the corals that succumb—to disease, to warming oceans, to hurricanes—but on the ones that live.

“These other corals are still here,” he’ll think. “What’s different about these? What can we learn from what is happening around us?”

All work on Florida’s Coral Reef by the Florida Aquarium’s Coral Conservation Program is conducted under permits.

At Moravian

Students Dive into Jamaica’s Marine Ecology

As part of a spring course on Caribbean coastal ecology, biology professors Joshua Lord and Natasha Woods took 15 students to Jamaica for 10 days over spring break. They stayed at the Discovery Bay Marine Lab and participated in a variety of scientific activities, including learning about local species and their habitats on land and in the sea, mangroves and coral reefs in particular (snorkeling required). “Our goals were to get students out of the classroom and create an immersive experience where they learn about the marine ecology, culture, and history of Jamaica in an authentic way,” says Lord.

Students Conduct Research into Marine Biology

Moravian University might be hours from the ocean, but in professor Joshua Lord’s laboratory on campus, students have the opportunity to examine a variety of questions in marine biology.

Lord’s lab currently focuses on understanding the behavior (predator avoidance, foraging, social hierarchies) of marine invertebrates, the influence the environment has on those behaviors, and how those behaviors affect the coastal ecosystem.

Moravian students have conducted a wide range of projects under SOAR (Student Opportunities for Academic Research) or for honors or independent studies. Examples include the following:

  • Shelter competition in grass shrimp
  • Predator–prey interaction between grass shrimp and fish
  • Social hierarchies in grass shrimp
  • Impact of ocean acidification on hermit crab hierarchies and feeding
  • Color change and camouflage in blue crabs
  • Impact of acidification on snail predator avoidance

Lord shares surprising details about recent research into the behavior of grass shrimp when confronted with a predator. “The assumption was that the shrimp would seek out shelter and hide,” says Lord, “but when we introduced fish predators into the tank, we saw the shrimp go up to the fish and poke at them until they retreated.”

Why was this surprising? We place invertebrates low in the animal hierarchy and therefore don’t ascribe to them behaviors absent in higher species, explains Lord. “You wouldn’t see a squirrel chasing a dog,” he says, “so we didn’t consider that grass shrimp would attack the much larger fish. Predator harassment has never been seen in marine invertebrates.”

What are the broader implications of this research, and why study marine invertebrates at all? There are several reasons, explains Lord. The behavior of grass shrimp likely indicates that the shrimp we enjoy from the appetizer tray display the same behaviors (shrimp are a multimillion-dollar industry). Grass shrimp are the main source of food for certain fish and blue crabs. Understanding these invertebrates helps us preserve healthy ecosystems.

“Furthermore, conservation efforts have gone wrong when we make assumptions about the behaviors of animals,” says Lord, who references the “Save the Bay, Eat a Ray” movement that began in 2007 when it was discovered that the population of the cownose ray had exploded in the Chesapeake Bay while the numbers of oysters, clams, and scallops declined. Researchers assumed that the rays were gobbling up these prized shellfish, so rays showed up in supermarket seafood cases and restaurant menus and were hunted by conservationists. Their population was decimated. Further research found that the rays didn’t even eat shellfish in the Chesapeake and that the ray population spike was an illusion based on migration patterns; the decimated shellfish populations were actually a result of overharvesting and shellfish disease.

In Moravian’s marine biology lab, students will continue to explore animal behavior and make assumptions, then test those theories carefully under Lord’s expert guidance.

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