A new study teams researchers with aquanauts to examine how factors such as low light exposure, ambient pressure, air gas mixtures, stress, and isolation may impact sleep.

The study, “Sleep/Wake Monitoring with Actigraphy During a 31-Day Underwater Marine Expedition,” is led by Joseph M. Ojile, MD, founder and CEO of Clayton Sleep Institute (CSI) in St Louis, and Christopher L. Drake, PhD, from the Henry Ford Hospital Sleep Disorders and Research Center.

It was done in cooperation with Fabien Cousteau’s Mission 31. Mission 31 is an ambitious ocean research and education expedition led by Fabien Cousteau, grandson of famed ocean explorer Jacques-Yves Cousteau, and began June 1 at Aquarius, a marine lab located 63 feet underwater off the coast of Key Largo, Fla, operated by Florida International University (FIU).

During their stay and for 7 days after returning to the surface, Mission 31 aquanauts wore an Actiwatch 2, a wrist device that electronically maintains a record in 1- to 2-minute intervals of the user’s activity, light exposure, and sleep pattern. The aquanauts also kept personal diaries of their sleep experiences.

“Research literature up to this point for sleep in individuals underwater has not shown much in the way of sleep disturbances. We think that’s because the study duration hasn’t been prolonged; only two weeks at most with just a hint of disturbance at the very end,” Drake says in a release. “Some of the aquanauts with Mission 31–Fabien Cousteau included–have been underwater for 31 days, which takes us into new territory.

“We believe that sleep disturbances begin to occur after the two week mark and become prominent at the four week period,” he says. “That’s what we are focused on and concerned about.”

Ojile says the data collected could potentially help to treat patients with sleep disorders.

“Data from extreme environments can often be used in normal circumstances,” Ojile says. “We may learn something interesting about changes in the aquanauts’ circadian rhythms, or the length of time it takes for their sleep to normalize after surfacing may be noteworthy. The exciting thing is that we don’t know what the research will show. That’s why we’re doing this.”

For more information on the study and the Clayton Sleep Institute research team, visit www.claytonsleep.com/undersea. To learn more about Fabien Cousteau’s Mission 31, go to mission-31.com.