UNIVERSITY PARK, Pa. — From Curaçao to Palau, the Caribbean to the western Pacific, Penn State scientists study the so-called rain forests of the seas — coral reefs, collectively one of the world’s most diverse habitats and home to an estimated 25% of all marine species. Led by biology professors Iliana Baums, Roberto Iglesias-Prieto, Todd LaJeunesse and Mónica Medina in the Penn State Eberly College of Science, the University’s coral research group is known the world round.

“We’re a powerhouse of coral reef research,” said Penn State Diving Safety Officer Tim White, director of the University’s Scientific Diving Program and the person in charge of training and certifying Penn State’s research divers.

All research divers in the United States are required to meet or exceed standards established by the U.S. Department of Labor’s Occupational Safety and Health Administration (OSHA) and arbitrated by the American Academy of Underwater Sciences (AAUS), a self-governing nonprofit organization composed of more than 140 member institutions, including Penn State.

“All of the member institutions provide an agreed-upon minimum set of training standards,” White explained. “And we have reciprocity, so if a student does a degree at another AAUS institution and gets their scientific diver rating, they come to Penn State qualified to dive with us.”

Through the AAUS Foundation, the academy also awards graduate research scholarships. In 2020, Eberly’s Kira Turnham — a doctoral student in the LaJeunesse lab — became the first Penn Stater to receive one of these awards, which has helped to fund her research on coral symbioses and climate change in the Pacific island nation of Palau.

Graduate research

Reef-building corals are symbiotic, hosting single-celled algae called zooxanthellae that provide the corals with food through photosynthesis and are protected in return by the corals’ hard skeletons.

Zooxanthellae also give corals their brownish hue that combined with the corals’ production of brilliant pinks, greens, blues, and purples gives thriving reefs their vibrant colors. But this intimate relationship is highly dependent on water temperature; too warm, and the corals expel the algae, losing their food source as well as their pigmentation in a potentially fatal process known as bleaching.

“I feel really lucky as a coral reef scientist,” Turnham said, “because where we dive in Palau, the corals are in fantastic shape.”

Palau’s corals, she explained, host a thermally tolerant algae that’s native to the region and has coevolved with its corals for millions of years. Studying their relationship could provide critical insight into the crisis of bleaching, which has worsened at an alarming rate with climate change and threatens corals worldwide.

“Palau is doing really well, but other areas aren’t,” Turnham said. “That’s part of why we study there, to better understand the dynamics of what’s happening around the world and why Palau is so special.”

Other Eberly graduate students are studying corals’ symbioses, physiology, genetics, and evolution to better understand the impacts of climate change — and hopefully find solutions.

Medina lab

In the Medina lab, Sofia Roitman and Julia Stewart are studying the effects of disease on Caribbean and Indo-Pacific corals and their associated communities of microorganisms. For both scientists, the research is highly personal.

“I feel a deep need to help the planet in any way that I can, and corals seem like a really excellent way to do that,” Roitman said.

“It’s really passion driven for me,” Stewart said. “I love coral reefs and I want to be able to save them.”

Iglesias-Prieto lab

In the Iglesias-Prieto lab, Tomás López-Londoño and Kelly Gómez-Campo are studying how corals acclimate to light.

López-Londoño is looking at the physiology, microbiomes, and host genetics of two Caribbean species, "putting all that information together to find out why they’re more abundant at certain depths."

Gómez-Campo is focusing on reef-building corals’ physiological, genomic and epigenomic responses to light and how they relate to stress.

“Corals’ capacities and strategies to photoacclimate reflect their remarkable plasticity and constitute a necessary baseline to better understand stress responses,” she said.

Claudia Tatiana Galindo-Martínez, who is studying coral bleaching and recovery, has been instrumental in collecting and cultivating specimens for the lab.

“I started taking care of them maybe three years ago,” she recalled. “And it was a challenge to keep them alive. But now they’re growing and healthy, so we can start to do some experiments with them.”

And Luis González Guerrero is investigating the role of corals in the global carbon cycle.

“My research shows how coral calcification — the process with which they build their skeletons — is, in fact, acting as a carbon sink,” he explained. “The implications of these results are huge when you consider that coral reefs are one of the oldest ecosystems and one of the biggest geological structures on the planet.”

Baums lab

In the Baums lab, Kate Stankiewicz and Trinity Conn are using computational methods to study Caribbean corals’ genomics and adaption to environmental change.

“My work revolves around genetic variation, to create new frameworks for understanding how we can improve conservation and restoration,” Conn said.

Stankiewicz specializes in computational biology and bioinformatics that, like Conn’s research, is focused on improving conservation. 

“On a personal level,” she said, “what drives me is basic curiosity, to contribute to building our knowledge — even if it’s just a small piece.”

COVID and beyond

The pandemic brought fieldwork to a halt with travel bans; and it set back lab work with closures, restrictions and supply chain disruptions.

The more senior students, who had already collected much or all of their data — Turnham, Roitman, Stankiewicz and the members of Iglesias-Prieto’s lab — could focus on their analyses and writing up results. But for Stewart and Conn, more junior than the others, it’s been over a year of adapting and recalibrating for lost time and data.

The Scientific Diving Program was also shut down, and although they developed safety protocols that eventually allowed them to resume training, persistent travel bans meant many divers were unable to complete the 12 annual scientific dives required to maintain their certification.

“We’re anticipating doing a lot of those dives this summer so people can get in the water and do their research,” White said.

Only time will reveal the pandemic’s full impact, and in the meantime much work remains to be done toward protecting and conserving the world’s corals. So, just as they’ve done all along, these Penn Staters are pressing on.