Dr. Claire Paris found that the truest way to study the behavior of fish was to become one.
The University of Miami oceanographer has spent countless hours underwater conducting her experiments. She had to be a strong swimmer and capable diver to do her life’s work in makeshift laboratories beneath the surface of the sea, whether she was in the Florida Keys, the Caribbean, the Mediterranean, French Polynesia, Norway’s fjords or Australia’s Great Barrier Reef.
She became so adept at navigating the deep that she decided to apply her skills to competition. Two months ago, the scientist became a champion athlete. Paris set the U.S. women’s free diving record in the dynamic no-fins event by swimming 128 meters (420 feet) in 3 minutes, 7 seconds underwater while holding her breath.
“The ocean has always been my sanctuary, and what I like is being one with the water, in tune with nature,” she said. “I put myself in the place of the fish larvae. I can have a better understanding of how they have to adapt to pressure, depth, current and all the variables of their environment.”
Paris wants to challenge herself and her students at UM’s Rosenstiel School of Marine and Atmospheric Science, where she is an associate professor of ocean sciences. She plans to attempt a depth record — she has already reached depths of 60 meters (197 feet) in practice — and compete for the U.S. free diving team at the world championships. Another goal is to create a scientific free diving class that would become part of the marine science curriculum nationwide.
Two years ago in Belize, during a study of goby larvae, Paris had to make repetitive dives of 40 to 50 feet to set the fragile baby fish free. Scuba gear could not be used because the bubbles and noise would disturb the movement of the fish. Paris relied on her basic free diving and snorkeling skills, swimming up and down on one breath of air.
Paris used her invention, the Drifting In Situ Chamber (DISC) to deploy the larvae. The DISC is like an immersible mobile nursery, with a transparent mesh chamber in which Paris can observe and record the fish remotely with a GoPro camera and microphone. Her studies tracking different species show that even infant fish are excellent navigators.
“People think that larvae are passively, randomly transported,” she said. “But they can swim. They use the same cues as older fish. They rely on a celestial compass to find their way. The sun helps them keep a bearing. Odor helps them follow a map. They have internal clocks linked to tidal phases. They have all the tools they need to get to and around the reef.”
Paris has analyzed the effect of sound on fish.
“We’ve found that larvae are emitting sounds, and they can hear the particle motion of the ocean,” she said. “They’re talking to each other, especially when they cannot see each other at night. They’re able to move together.”
Free divers mimic fish in order to reach great depths smoothly and efficiently — but on one breath of air. Paris knows better than most: She is an expert on the biomechanics of fish.
“We have shown that the larvae are swimming not just horizontally, but they also undergo vertical migration, which helps them avoid predators,” Paris said. “They go through a sink phase, just like free divers.”
Paris talked about the projects she has undertaken around the world from her Physical-Biological Interactions Lab at the UM Rosenstiel School on Virginia Key, which contains tanks full of damselfish, gobies and shrimp and a prototype of the DISC.
She has studied many species, including snapper, grouper, blue marlin, lionfish, conch and spiny lobster. She has been a pioneer in numerical modeling to measure their pathways, patterns and connectivity to marine populations, as well as how they are affected by climate change, plastic pollutants and oil spills. Working with the Sea Image consortium at the University of South Florida, she predicted that submerged oil from the Deepwater Horizon spill in the Gulf of Mexico would form a deep plume and move to the southwest.
During the expedition in Belize, Paris, 57, became intrigued by the idea of pushing her limits as a diver. She has competed in triathlons and marathons. She figured she would try the sport of free diving — so called because divers are unencumbered by scuba gear and the decompression restrictions of breathing compressed air through a regulator.
“Claire is a very athletic, competitive person who qualified for the Boston Marathon on her first try,” said her husband, Ricardo Paris, a Coconut Grove entrepreneur who joined her in free diving classes and has since become an instructor for Grove Scuba and his wife’s coach. “She used to race motorcycles and get into wrecks. She had two bad bike accidents. She injured her knee running. Free diving was a good sport for her because she couldn’t hurt herself.”
The couple took a course with Performance Free Diving and learned more about equalization, breathing exercises and breath-hold techniques. Claire Paris trained at local swimming pools and in the ocean. She competed at events in Curacao and the Cayman Islands. Her personal record for holding her breath in a static position: 5:34.
The sport proved an ideal match for Paris’ personality because the data-examining scientist also has a spiritual side. She practices Kundalini yoga, including 4 a.m. to 6:30 a.m. sessions that require extended holds of poses, meditation and mantra chanting. She grew up in Carcassonne, France, and developed an affinity for the outdoors while snorkeling, surfing and sailing off the coast.
“The conundrum of free diving is that you have to relax your mind or you burn oxygen,” Ricardo Paris said. “Claire is like a fearless yogi down there. She’s enjoying the ride on the way down and the way up. It combines her aquatic abilities, lung power and stamina with her tranquil characteristics.”
Paris’ love for free diving grows every time she experiences the zen moments of negative buoyancy, descending one meter per second.
“You don’t feel the urge to breathe at that point,” she said. “Time stops. You turn off your thoughts. You feel the water and your heartbeat.
“I go down without a mask, only a noseclip. I open my eyes. It’s beautiful and peaceful.”
Water is 800 times denser than air. The human body adapts to underwater pressure much like marine mammals by slowing the heart rate, producing more red blood cells and shunting blood from the extremities to the core. But the most painful challenge is learning how to use the air inhaled at the surface, which gets compressed, to equalize pressure in the spaces in the sinuses and Eustachian tubes.
During a recent training camp in Dominica with world champion Jonathan “Johnny Deep” Sunnex, Paris learned an equalization method of keeping the Eustachian tubes open that she hopes to apply at the Vertical Blue competition at Dean’s Blue Hole in the Bahamas next year. Of the various disciplines — dynamic (in a swimming pool), free immersion (holding a rope going down and up), constant weight (no fins or with fins or monofin) and the extreme no limits (riding a weighted sled down a cable and inflating a lift bag to ascend) — Paris prefers constant weight with no fins because it is the most natural.
At the 2014 world championships in Sardinia, she met Natalia Molchanova, 53, a Russian sports psychologist and 41-time world record-holder whose marks included 69 meters (226 feet) in constant weight no fins, 101 meters (331 feet) in constant weight with fins and 9:02 in static breath hold. Paris and Molchanova, both in their 50s and each a mother of a son and daughter, became friends.
On Aug. 2 in Ibiza, Spain, this year, Molchanova died when she failed to surface from a modest recreational dive. It was a bewildering accident in a sport that stresses safety.
Two weeks later, Paris felt Molchanova’s presence when she set her national record in Los Angeles.
“We had talked about how age is not a limit yet you have to understand your physical limits, which I do because I’ve never had a blackout,” Paris said. “She was with me during my record swim. I was listening to her advice when I asked, ‘Can I keep going?’ And I did.”
How deep can she go? Paris intends to keep pushing. The desire to explore is in her DNA. She will keep following the fish, in her research projects and her free dives.
“As a scientist I am a member of academia, and as a diver I’m a member of the water tribe,” she said. “A skill that was useful for my job has become my passion.”