Hakai Magazine

Coastal science and societies

Marine animal movement expert James Liao
At his lab at the University of Florida, James Liao investigates the “how” of marine animal locomotion. Photo by Michael LeGrand

Coastal Job: Marine Animal Movement Expert

James Liao studies the mysteries of marine animal movement with an eye to unlocking solutions to human problems.

Authored by

As told to Stephenie Livingston

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Some people work in cubicles, others work in kitchens, but the most intriguing workplace of all may be the coast. Meet the people who head to the ocean instead of the office in our Coastal Jobs series.

James Liao, a biomechanist and neuroscientist with the University of Florida’s Whitney Laboratory for Marine Bioscience, investigates the way marine animals move in an unpredictable world. His studies into fish biomechanics provide insights useful for technology, engineering, and health.

Ever wonder if all fish wiggle their tails the same? Or how they know when to school versus hide behind a rock in a stream? It’s questions like these that keep me up at night. I want to know how underwater animals move and what they’re sensing, so we can harness the genius of their evolutionary design.

Growing up in New York City as the child of Taiwanese immigrants, I fished the East River with my angler dad, chased frogs in Brooklyn’s Prospect Park, and read everything about Jacques Cousteau. When I was eight years old, I said, “I want to be a marine biologist when I grow up.” Sometimes it happens like that, I guess.

I was always fascinated by watching animals maneuver through water and wondered how and why they move the way they do.

I’ve studied everything from coral reefs to marine mammals in pursuit of answers to questions about the role body shape, senses, and genetics play in their movement. The most exciting aspect of my career, though, has been learning to understand the world the way a fish might. It’s humbling how little we know about such common creatures. Answering seemingly insoluble questions about why fish swim the way they do could lead to surprising innovations: underwater technology inspired by their movement; aids and treatments for hearing and visually impaired people based on their senses; and structures, like dams and bridges, engineered with the fish in mind.

At Harvard, I proved that fish surf underwater. That’s right—fish can surf. When we think of fish, usually we picture an environment similar to goldfish in a bowl. In reality, their environments are full of energy. So, I wondered if fish swim in a way that could exploit underwater turbulence.

To test the idea, I sprinkled reflective particles into a tank designed to replicate natural turbulence. Next, I shone a laser through the moving water to illuminate the particle-filled tank, which looked like a shaken snow globe. As fish swam, they generated swirling patterns in the lit particles. I used a high-speed video camera to capture and reconstruct their movement. Turns out, fish use turbulence as a way of boosting themselves forward, while minimizing energy output. This find elucidated questions such as why fish swim behind each other when they’re schooling: they’re surfing on the group’s collective energy to propel forward with less effort.

The discovery allowed engineers to create a mechanical fish that generates electricity when it moves, and could inform the development of future underwater technology powered by ocean energy.

My research group at the Whitney Lab has been studying the tiny hair cells on the skin of fish that allow them to feel without touching. These cells translate sound and movement from the environment and send signals to the fish’s brain, telling it when and where to swim. The cells are identical to the ones we have in our ears that help us hear. But, unlike fish, we can’t regenerate them. It’s easier to study fish than humans, so we’re working to determine how fish hair cells work so we can better understand human hearing loss.

Now I’m off to fly fish in New Zealand. While there, I’m collaborating with a group of scientists who are concerned that hydroelectric dams are cutting off spawning habitat. That’s something I want to get into more—influencing the design of engineered structures so they’re built with underwater life in mind. Someone should ask the fish what they want and advocate for them.

Oh, and to answer my initial question: we think that all 39,000 fish species do wiggle their tails the same.