Marine Biologist & Science Communicator
Assistant Professor of Marine Science at Eckerd College, Saint Petersburg, Florida. Principal Investigator of the Shark Conservation and Predator Ecology (SCAPE) Lab.
Dr. John Hlavin is a marine biologist and science communicator focused on sharks, rays, and other predatory fish. He is an Assistant Professor of Marine Science at Eckerd College in Saint Petersburg, Florida, where he teaches Principles of Ecology (BI 301) and Elasmobranch Biology and Management (MS 315). He is the Principal Investigator of the Shark Conservation and Predator Ecology (SCAPE) Lab.
Dr. Hlavin earned his B.S. cum laude in Biological Sciences from the University of Notre Dame and was a NOAA Hollings Scholar. He completed his Ph.D. in Environmental Science & Policy with honors in 2026 at the University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science in the Shark Research and Conservation Lab (advisor: Dr. Catherine Macdonald). His dissertation is titled “Refining nursery management with fine-scale ecological data: Multi-tracer reconstruction of shark trophodynamics across ontogeny.” He is an Abess Fellow.
Dr. Hlavin is a Save Our Seas Foundation Project Leader studying Atlantic guitarfish and was the inaugural 2024 Florida Sea Grant Guy Harvey Fellow. He conducts field research and education with Field School, leading shark and ray capture, handling, and sampling instruction. He is a member of the inaugural cohort of Monterey Bay Aquarium Ambassadors and was formerly a Guy Harvey Ambassador.
Dr. Hlavin's work combines field ecology, trophic science, and conservation biology to understand how sharks and rays use coastal ecosystems — and how we can better protect them.
Understanding trophic connectivity is central to shark and ray conservation. Dr. Hlavin uses minimally invasive techniques — stable isotope analysis and DNA metabarcoding — to untangle elasmobranch predator–prey relationships and foraging strategies across life stages.
Age-dependent resource use in sharks and rays is often overlooked by fisheries management. Dr. Hlavin's ongoing Tampa Bay habitat survey identifies critical nursery habitats and monitors ecological change over time.
U.S. coastal waters serve as a refuge for globally threatened elasmobranch species, including the Critically Endangered great hammerhead shark (Sphyrna mokarran). Florida's coastal development and recreational and commercial fishing threaten these populations, and their cumulative impacts remain poorly understood. Dr. Hlavin's research aims to fill these critical knowledge gaps.
Selected peer-reviewed articles. Full list available via Google Scholar.
Hlavin & Macdonald. Ecology and Evolution, 2025.
DOI: 10.1002/ece3.71473
Hlavin et al. Environmental Biology of Fishes, 2025.
Hlavin, Saltzman, D'Alessandro & Macdonald. Frontiers in Marine Science, 2026.
Select press coverage and media appearances.
Research matters most when it reaches people. Dr. Hlavin shares ocean science with the public across social media — translating peer-reviewed work into stories that resonate beyond academia.
Dr. John Hlavin — Assistant Professor of Marine Science, Eckerd College, Saint Petersburg, Florida.