How a biomedical researcher is making the future of diving safer

Dawn Kernagis never set out to be a biomedical researcher, but 14 years into a cavediving career, she had questions. Namely, why did some of her friends suffer from decompression sickness while others seemed virtually untouched by it?

“It’s a self-selecting community; if you get the bends on a dive, you are less likely to do anything more aggressive,” says Kernagis, who began cave diving at age 16. “But why are some people more susceptible to decompression sickness? What is filtering people out? I wanted to find a marker that shows when my body is responding to decompression stress and tells me that I’m on my way to developing DCI.”

And it turns out that marker is not the presence of bubbles in the bloodstream.

Says Kernagis, “There is a lack of correlation between bubbles and DCS. Bubbles tell you that a diver has bubbles, not necessarily DCS.” Instead, her research, starting with her doctoral work at Duke University, led her to find those markers in genes. Genes identify hair and eye color, but that’s a fraction of the story.

“Every process in our body, from growing fingernails to when we bleed, is regulated by genes,” says Kernagis, who now works with the Florida Institute for Human and Machine Cognition in Pensacola. “For example, when we are sick, certain genes ramp up to activate our immune system.”

When Kernagis started, she was looking at 14,000 data points across the whole spectrum of genes. Her work so far has led her to narrow that number significantly, initially to 700 genes. She adds, “Now, we’ve found 350 genes that are strongly turned on and off from decompression stress, namely in inflammation, coagulation and the body’s stress responses. Our body has increased stress responses to pretty much everything we do — daily stress, exercise, eating certain types of food and drinking alcohol.”

And just as our genetic makeup can influence our risk of DCI, Kernagis and her team found there are changes that can occur in the way those genes are read — called ‘epigenetic’ changes — which could impact a diver’s risk of developing DCI.

She and her team will continue to narrow their research until they home in on one or two genes that can predict DCI risk or decompression-stress development. The goal is to be able to test the blood via a pinprick following a dive to determine if a diver has DCS.

But her research is also more far-reaching. At IHMC, she and her co-workers also study how nutritional approaches and better training might not only keep divers safe, but also help them perform better. And her work will benefit anyone, including astronauts and high-altitude pilots, who works in extreme environments.

For this reason, she was selected in 2016 as one of six chosen to participate in NASA’s Extreme Environment Mission Operations, or NEEMO 21, living 62 feet deep in the underwater Aquarius Reef Base off Key Largo, Florida. One area of study that she focused on at the time was the effect that prolonged submersion has on gut bacteria.

“A lot of this is forward-thinking — we won’t be using it tomorrow. But it’s possible that we will be working toward personalized dive tables based on genetic makeup.”

And if personalized tables are possible, then so is a dive computer that predicts each diver’s risk to prolonged exposure. Says Kernagis, “This is so far into the future, but we have to start somewhere.”

Not Quite 9-to-5

If being an astronaut is out of the question, Kernagis might have found the next best thing. She and a group of five other aquanauts took part in the 16-day NASA Extreme Environment Mission Operations 21 expedition in 2016, living at 62 feet to perform studies at the world’s only undersea research station. The goal: “explore tools and techniques being tested for future space exploration,” per NASA, including Kernagis’ study on the effects prolonged submersion has on gut bacteria.

Check out some footage from the expedition below.