A Mississippi shark expert takes a starring role on the SharkFest predatory pageant.
Eons ago, when Earth’s earliest ancestors first wriggled from the sea onto land, some species made the leap permanent. Others — like the majestic whale and acrobatic dolphin — returned to the ocean depths, rejoining ancient leviathans that never left. Among those long-time residents of the deep is the tiger shark: striking, elusive, and endlessly fascinating to marine biologist Marcus Drymon, Ph.D., Associate Extension Professor at Mississippi State University and Marine Fisheries Specialist with the Mississippi-Alabama Sea Grant Consortium.
As tourists flock to coastal shores each summer, shark fever grips television screens during a frenzy of documentaries that dive into the mysteries of the ocean’s apex predators. Marcus has become a familiar face in this world, appearing in several episodes of SharkFest, National Geographic’s popular July series exploring the behavior of sharks and their vital role in ocean. His latest research adds a surprising twist: juvenile tiger sharks found in the Gulf carrying the remains of small inland birds — the same songbirds that brighten Southern backyards and fill summer mornings with birdsong. The discovery raises new questions about the secretive lives of these striped hunters, and why what they eat might be telling us more than we thought about the connection between land, sea, and sky. 
HOOKED ON SHARKS
Before joining MSU, Marcus was part of the marine sciences faculty at the University of South Alabama and the Dauphin Island Sea Lab, where much of his research began. His obsession with sharks — the way the rhythms of the ocean guide them through a landscape that is both familiar and ever-changing — dates back to childhood
“Like most small kids — 7 or 8 years old — I was fascinated with all things shark,” says Marcus, a Kentucky native. “My dad is an airline pilot, so we had the good fortune to travel all over the world because of his job. I had the opportunity to see a lot of exciting marine places like the Bahamas, other parts of the Caribbean, Mexico, and South America. That’s where I developed a love for the ocean, and, in particular, sharks.”
Like many terrestrial dwellers, Marcus feared sharks—their ominous profile, prominent dorsal fin, and gimlet eye.
“I would see them in the water when I was snorkeling or on a boat, and I would just force myself to stay in the water and check them out,” Marcus says. “The longer I was able to stay in the water with them and observe them in their natural settings, the more curious I became and the more enamored I became. That led to me reading everything I could about them and, ultimately, going to college to study them.”
From analysis at the Bimini Biological Field Station in the Bahamas with lemon sharks in his early research days, Marcus has continued to catch and study all species of sharks, measuring, examining, and tagging them for release. During 20 years of research, television producers often contacted him about his studies, several of which have been highlighted during SharkFest.
“It’s a thrill to see all of the work you’ve been putting in and what you’ve learned being displayed to a broad audience,” Marcus says. “With respect to the tiger shark studies, I think it’s just such an unusual marriage between a large, highly migratory predatory species like a tiger shark and then tiny, quaint, and unassuming songbirds. That kind of juxtaposition really defined that study and made it interesting.”
In his examination of young tiger sharks, Marcus saw — when flushing (lavaging) their stomachs, a striking number of songbirds had been consumed. The question then becomes, “Why?”
“To see a tiger shark occasionally eat a little songbird is interesting, but it’s not particularly rare,” Marcus says. “I think what was neat about our study was trying to draw these linkages, saying, OK, the prevalence of these sharks eating small birds is much higher than we would expect due to random encounters. There must be something about the patterns of these migratory birds and/or the hunting strategies with these small tiger sharks that lends itself well to that interaction. We found that these individuals are more prone to eat things they didn’t have to actively hunt.”
With songbirds falling from the skies like apples from trees, they present an easy meal for a young predator learning to hunt. Imagine a hollow-winged creature flying determinedly along its migratory route, hitting a storm over the Gulf of Mexico, and in exhaustion landing on the swells of an inhospitable sea. The result is a cycle-of-life ending to that bird’s pilgrimage.
“We felt like the most satisfying aspect of that project was tying together those two things and establishing those linkages,” Marcus says. “These birds leave the Yucatan Peninsula in Mexico and fly nonstop until they hit the continental U.S. Their first real opportunity to stop is on Dauphin Island, Alabama. Where we’re located is a unique area in terms of the migratory patterns of songbirds.”
The tiger sharks feeding on birds are neonates — yes, 3-foot-long “baby sharks” — in a species that grows quickly. By age 3 to 5, they can be 10 feet long.
That’s just one of the factors that makes this possibly Marcus’ favorite species to study. The blunt-nose predators are also one of the most voracious and are known as “the garbage can of the sea” for their tendency to eat anything they find.
“They have an extraordinarily wide dietary breadth — fish, crustaceans, small marine mammals, terrestrial birds, marine birds, debris, and trash,” he explains. “They’re also highly migratory, which I think is fascinating.”
Marcus is studying the area about 60 miles off the coast of Louisiana, Mississippi, and Alabama, where the research vessels bring in all manner of sharks—blacktips, hammerheads, sandbars, bulls, spinners, and more.
“Now, we’re seeing shark populations that are relatively stable, if not slightly increasing,” Marcus says. “This is really good news. We know that sharks were over-fished significantly in the ’80s and ’90s. And it wasn’t until the mid ’90s with management measures in place that we started to see their populations start to recover slowly. But because of their life history traits, they grow very slowly. They’re late to mature. Once they’re overfished, their populations take a long time to recover. Fast forward 30 years from the mid 1990s and here we are finally in 2024 seeing populations slowly recovering.”
Marcus explains that the Gulf of Mexico is one of the world’s best examples of a well—managed, sustainable shark fishery.
“Sharks are a resource to be harvested just like a red snapper or speckled sea trout,” he says. “A lot of people eat shark. Science-based fishery management plans are the foundation of sustainable fisheries for sharks, but this is different than culling sharks.”
Marcus and his team are now focusing their studies on depredation, which occurs when a shark targets a fish an angler has hooked and is battling to get to the boat. This human-wildlife conflict has steadily escalated in the past 10 years, and Marcus is seeking to determine why these encounters are on the rise.
“We want to understand what we can do to reduce those types of interactions,” he says. “We want to reverse the narrative that’s starting to build, which is, ‘The narrative has changed from ‘sharks threaten our safety’ to ‘sharks threaten our recreational fishing opportunities.’
“We’re working hard to remind people just how cool sharks are, and that they are an important part of a healthy ecosystem.”
With their dorsal fins cutting through the surface or deep beneath the azure waves, sharks embody the spirit of the ocean itself—mysterious, majestic, and undeniably captivating.
