Aquarius Undersea Lab helps researchers save coral reefs

By Rebecca Burton

Key Largo is home to one of the world’s most vibrant coral reef systems, but overfishing of important herbivorous fish could threaten the health of these wonders that divers and snorkelers alike hold dear.

Deron Burkepile, 34, assistant professor of marine biology and oceanography at Florida International University, discovered this in 2004 during a 10-day research mission on board the only underwater sea research vessel in the world, the Aquarius Undersea Laboratory.

Located in the Florida Keys National Marine Sanctuary, the Aquarius sits about 60 feet deep at the base of Conch Reef, about four miles from Key Largo. Aquarius is operated by the University of North Carolina Wilmington and is owned by the National Oceanic and Atmospheric Association.

By living in the submarine-like pressurized habitat, divers’ bodies become saturated with the maximum partial pressure of gas possible for that depth, a technique called saturation diving. Once their body tissues are saturated, they can dive for up to nine hours in one day, and avoid the deadly decompression sickness known as “the bends.”

After a long day of diving, scientists, also called aquanauts, sleep, eat and even use the Internet for days at a time, something unheard of in any other laboratory in the world.

This is possible from the Life Support Bouy that sits at the surface and is about 30 feet in diameter. The LSB is a platform that is connected to the sea lab and provides all of the gases needed for breathing underwater. Although convenient, the experience may not always be the most comfortable.

“The hardest part is being cold all the time, and constantly losing body heat,” Burkepile said, referring to the heavy air conditioning used in the lab to keep the correct air balance.

Joeseph Pawlik, 51, professor of marine science at UNC Wilmington, has conducted four missions since 1995 but has never been an aquanaut himself.

“I get cold too easily,” Pawlik said. “But I never have trouble finding interested students to send down. The hardest part is denying students the opportunity to go.”

The prolonged experience allows divers to conduct extensive research that would be impossible if they had to return to the surface often. It is also more cost- and time-efficient.

In Pawlik’s most recent mission, he sent students to monitor Caribbean barrel sponges. The information the aquanauts found could be important to monitoring the future effects of the BP oil gusher in the Gulf of Mexico.

Scientists who want to conduct research using Aquarius submit grant proposals to NOAA. If the proposals are deemed useful, scientists are invited to conduct their missions. The research they find is to help benefit the marine habitats not only in South Florida, but also around the world.

The Aquarius was built in 1986 and was first placed in the Virgin Islands. Thirteen missions later, it was moved to Wilmington to be refurbished after damage from Hurricane Hugo. In 1993, it was moved to its current location, and has since been home to more than 90 successful missions, including Burkepile’s.

The director of Aquarius, Thomas Potts, 46, said that since its time in Key Largo “scientists have acquired a long-term dataset that is essential to comprehensively and intimately studying and documenting changes in a coral reef ecosystem that could not be attained by disparate research projects alone.”

Burkepile’s mission is proof of that.

His mission was to reveal the need for diversity of herbivorous fish in coral reef systems. Burkepile and his group made small cages up and down Key Largo’s reef system to study how different fish eat different seaweeds.

“We got to eat, sleep, and dive,” Burkpile said. “It was awesome.”

After nine hours of diving for 10 days, Burkepile and his group of scientists found that certain species of seaweeds aren’t eaten enough and their overgrowth could potentially harm the corals. He and his team also concluded that overfishing of certain herbivorous fish was affecting the seaweed balance and, therefore, the health of the coral systems.

Burkepile’s missions along with others at the laboratory have helped produce more than 300 peer- reviewed scientific publications, but scientific research isn’t the only use for the Aquarius.

Potts said the sea lab is also used for undersea technology development and for ocean education and outreach as well as a national training facility for scientific divers.

Unlike Jules Underwater Hotel in Key Largo, not just anyone can stay at Aquarius. Divers must go through five days of additional SCUBA training.

“We had to go through intense training,” Burkepile said. “Our instructors would mess with us, pull off our masks, and imitate actual emergency situations.”

Potts credits the stationary position of the Aquarius to its success.

“I think the biggest benefit of the Aquarius is that it has been in place for 20 years in one location,” Potts said. “We can document long term changes and have long term data, which is very rare.” Pawlik agrees.

“Key Largo is an excellent location with a great reef system,” Pawlik said. “There is a lot of topography and internal waves. The longer the laboratory is there, the more valuable information we can get.”

A version of this story also appeared on the website of the national conference of the Society of Environmental Journalists at the University of Miami. You can see this and other class work for SEJ at or by going to