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Submerged in Flathead Lake: A Submarine Expedition

For the first time this summer, an underwater expedition took scientists into the depths of Flathead Lake. They used submarines to capture videos of fish and microscopic animals. A robotic arm protruding from one of the submarines collected algae and scooped sediment samples from the floor and a night dive shed light into the way invasive shrimp migrate throughout the lake.

Pictured here is the R300 submarine in Flathead Lake. Photo courtesy of Cliff Redus.

The expedition was a rare chance for local scientists to take advantage of privately-owned submarines. “I thought it was a great opportunity. We have never had a submarine in the lake before,” explains Jim Craft, the Flathead Lake Biological Station research scientist who spearheaded the project.

“I really wanted to get a feel for what is deep in the lake,” he adds. “We can send samplers and probes down okay, but we’ve never had someone actually down in there looking at the lake and taking video.”

The technology allowed University of Montana graduate students, faculty and resident scientists to collect data in altogether new way. Submarines can dive deeper and stay in cold water longer than divers. They can measure water temperature at different depths within the lake, and can capture images and video while monitoring oxygen and pressure levels in the cabin.

Submarine owners Cliff Redus and Hank Pronk donated their submarines to the project. They are part of a group called InnerSpace Science that connects scientists to submarine owners. “It is a great opportunity to utilize the machines we have worked so hard on to build,” Pronk says.

Pronk started building his first submarine when he was 16 and finished it when he was 20. Since then, Pronk has built a half dozen more submarines. He brought his two-person sub, the Nekton Gamma, to Flathead Lake for three days in early August for the expedition. “It’s one thing to go out and have some fun in the lake,” he explains. “But it is more rewarding to do some useful work with it.”

With more than 1,000 submarine dives under his belt, this submarine expert considers submerging into deep frigid water is “business as usual.” But he enjoys taking other people into the vessel.

“Whenever you take a passenger for their first time in a submarine, it is always very fun,” he says. “For the most part, they are so excited they are jumping for joy.”

Cliff Redus owns the R300 submarine used in the Flathead exhibition. A longtime underwater enthusiast who lives in Texas, says his childhood dream was to design and build his own submarine; that dream became a reality about a decade ago. He uses the word “outstanding” to describe the feeling you get submersing into the water.

“It’s absolutely a kick. When you are sitting on top of the water, you can see all around you – including the people on the boat or the dock. When you hit the button to start flooding the main ballast tanks and you start to go lower and lower, and you can see both above and below the waterline.”

At first, it can be a little bit scary because you rely on the submarine for your support and protection, he said. “But when you submerge completely, you find yourself in a fascinating world. Fish come up to the viewpoint and you can see the rocks and terrain,” Redus explains.

The scientific exhibition at Flathead Lake took the submarine owners and scientists to several areas around the lake. They took samples and underwater footage of the lake ecology from the waters around Painted Rock, Woods Bay and Bird Island. They also captured soil samples from the mouth of the Flathead River – a major contributor of pollution into the lake.

A highlight for both scientists and submarine captains was a night dive at Yellow Bay. “This was one of the first times we’ve done night dives,” Redus says. As the sun subsided the marine vessels sunk into Yellow Bay, he explains, “people on the docks could see the bright lights of the submarine get darker and darker as they got deeper underwater.”

The submarine captains could see mysis shrimp as they lowered to about 200 feet below the surface. The data collected during the night dive may well shed light as to how the mysis shrimp, the invasive species introduced into the lake in 1970’s, move throughout the lake.

Flathead Biological Station scientist Jim Craft says the data collected by the submarines will not only contribute to current research projects; it may also provide important baseline data critical to funding future scientific projects at the lake.

“One of the reasons why I was so excited when I got a position working here is that we are in an area where we can understand how ecosystems function naturally. Instead of trying to learn how to fix those things, we can try to understand just how they work.”

“On Flathead Lake,” Craft adds, “Mysis shrimp have certainly impacted the lake, but there are also lakes in Glacier Park and the Bob Marshall Wilderness that now we do valuable work as well. Those lakes truly aren’t impacted very much. It’s nice to get a handle on how large lakes should operate naturally.”

Flathead Lake Biological Station scientists look forward to seeing the full results of the submarine expeditions within the next six weeks. Meanwhile, submarine captains Pronk and Redus plan to use their submarines for scientific research projects throughout the U.S. for many years to come, including potential follow-up to the data collected on Flathead Lake.

—Breeana Laughlin

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