Faculty Focus: Associate Professor of Biology Kristen Whalen

She’s completed more than 500 dives in oceans and seas worldwide, but Associate Professor of Biology Kristen Whalen’s expansive underwater journey began in a much more unassuming environment: cleaning tiles in her unheated backyard pool in landlocked Michigan. Whalen says that her mother, who never learned to swim, was determined that Whalen and her sister would. “My mom would tell me I needed to clean the algae and grime off the tiles,” Whalen recalls. “So, I learned to snorkel while I was cleaning the pool.”

“And as everyone knows,” she adds, laughing, “every marine biologist comes from the Midwest.”

During family trips to the Caribbean as a young teenager, she became enamored with the colors, textures, and incredible biodiversity of reefs, establishing what's become a lifelong fascination with marine life. This enchanting environment kindled her dream of pursuing marine biology, even though she admits she wasn’t quite sure what the field entailed. 

“I tell my students I'm a weirdy in that I knew what I wanted to do since I was 13, which is not common,” Whalen says. “I very much wanted to get a degree in marine biology, but I really didn't know what that meant exactly. It just felt really exciting.”

Since those formative moments, Whalen’s career has been characterized by a willingness to dive headlong into the unknown, which usually requires the ability to dodge sharks, stingrays, and unpredictable ocean swells. As a marine biologist and an expert in biochemistry, she is deeply interested in the chemical conversations occurring beneath the waves and the potential they hold for bolstering human health. Her research is centered on two points of inquiry: how chemical signals shape the interactions between marine species and whether those naturally produced compounds can be leveraged to develop new medicines, particularly antibiotics that can fight off a rising number of drug-resistant bacteria.

Whalen says engaging in research early during her undergraduate studies helped shape her career trajectory, and she strives to replicate that experience at Haverford. While pursuing her bachelor of science degree in the marine biology program at the University of North Carolina Wilmington, she worked in a coral reef ecology lab beginning as a freshman and spent summers and breaks in the academic year collecting samples in the Florida Keys and the Bahamas. By her sophomore year, she had already co-authored her first scientific paper and presented at her first international conference. 

In her Ph.D. program in the Joint Program at the Massachusetts Institute of Technology and  Woods Hole Oceanographic Institution, Whalen explored how marine invertebrate predators that feed on noxious soft corals were capable of metabolizing the myriad natural products they encounter using molecular pathways mirroring those in the human liver. Her dissertation focused on the biochemical defenses of the flamingo tongue snail (Cyphoma gibbosum), the only reef predator that can safely eat toxic soft corals. 

“Participating in research as an undergraduate was so profound in helping me develop skills and become confident, and has shaped me into the scientist that I am today,” she says. “Learning is messy. You make mistakes, you build on things, and you figure it out. That’s such an important aspect of learning.”

In the lab and in the classroom at Haverford, Whalen integrates her enthusiasm for the world’s most vast ecosystem into her pedagogy, blending rigorous, hands-on research at the bench with field excursions around the world. Her students also have access to an expansive collection of cryogenically stored marine bacteria, a resource generated by students in BIO201 lab and a former senior thesis student Abigail Keller ’17—more than 1,500 strains collected from reefs, marine plastics, lobster carapaces, and even whales—giving them opportunities to uncover new chemistry with potential as new treatments to fight human pathogens while also gathering insight into how marine ecosystems are shaped by chemical interactionsat the molecular level. 

Whalen says her lab has identified bacterial compounds that influence phytoplankton behavior, including one that prevents viral mortality in these tiny, photosynthetic oxygen-producing organisms. The humble and overlooked phytoplankton, Whalen says, plays a critical role in food webs and carbon cycles in the ocean. “They produce about 50% of the oxygen we’re breathing,” she says. “They also play a very important role in maintaining the Earth’s climate, cloud formation, and keeping the Earth cool.” 

One of her and her students’ most important discoveries came in 2021 when she and her students identified a bacterial compound that protects phytoplankton from viral death. Although the molecule had been discovered in biomedical research in 1999, it had yet to be discovered in the ocean. A bacterial communication molecule produced by the marine bacterium Pseudoalteromonas stops phytoplankton in the cell cycle, Whalen says, putting it into a sort of “zombie-like trance,” altering the physiology of the phytoplankton host and conferring protection from viral lysis.  

Viruses are the most abundant biological entities in the ocean, Whalen says. “There are more viruses in the ocean than there are stars in the sky. Viruses turn over about 20% of the phytoplankton biomass per day, so there’s a lot of viral death in the ocean. But the viruses that infect them do not infect humans, so we can work with them easily.” 

This turnover of phytoplankton biomass by viral infection, lysis, and ultimately death is a natural process that happens daily in the ocean and terminates large phytoplankton blooms you can see from space via satellite pictures. So it was a significant finding for Whalen and her students to find that a molecule produced by associated marine bacteria could impact such a fundamental process in the ocean.

Whalen believes the implications of that discovery might extend well beyond marine ecosystems. She says that understanding how the chemistry of microbes influence a host’s biology can shed light on similar processes in humans, particularly in our gut, where bacteria play a leading role in influencing host health and disease. 

More recently, Whalen has expanded her research to include sea urchins in her 666-liter saltwater aquarium housed on the ground floor of the KINSC’s East Wing. She says their embryos are excellent developmental models in human biology, as sea urchin embryos possess proteins similar to ones found in human cancer cells. Whalen plans to use urchin embryos as a screening tool to discover new compounds from her marine microbial library that impact the function of these proteins overexpressed in metastatic tumors.

The opportunity to mentor Fords is central to her role at the College, Whalen says, and many of her students have pursued medical school or careers in environmental science and pharmacology. She has taken her students on research trips around the globe, including a 2019 expedition to Roatán, an island off Honduras that boasts clear, turquoise waters and some of the healthiest coral reefs in the Caribbean. 

“We snorkeled in some of the healthiest Caribbean reefs I had ever seen in my life. It was pillar coral, huge sea turtles, manta rays, and sharks for days,” Whalen says of the trip. “One student had never been to the ocean before. She grew up in Iowa and taught herself how to swim in lakes just to prepare for the trip.”

For Whalen, providing such experiences is about much more than introducing students to research. It’s about expanding perspectives and building confidence, something she is keenly attuned to as a woman in STEM. Whalen supports students from a wide range of backgrounds, helping them secure funding to attend conferences while ensuring that financial barriers don’t hinder research opportunities. She also leads frank discussions about imposter syndrome, those unshakable feelings of self-doubt that affect many students, especially those from underrepresented groups in academia. 

“When I was a student, a lot of doubts came into my head. Am I good enough? Should I be here? Is this the right place for me? Will I succeed? I’ve gotten much better about tamping them down,” Whalen says. “Now, when students come into my lab, the first thing I ask them is, ‘How can I help you be the best person you can be or provide you opportunities to excel and achieve  your dream?’ I think that's really empowering.”