Dogs, subs are newest AIS detection tools
Dogs and submarines took center stage at the Flathead Lake Biological Station open house last week as a large crowd learned more about the station’s efforts to detect and prevent aquatic invasive species from entering lakes and waterways in the Flathead Lake watershed.
Phil Matson, who coordinates the bio station’s efforts to detect and prevent aquatic invasive species, pointed out the current focus of those efforts is quagga and zebra mussels.
Zebra mussels are believed to have arrived in America as stowaways on European ships in the mid-1980s, Matson pointed out They were first discovered in the Great Lakes in 1988. Barely the size of a fingernail, they grow and adhere by the thousands to underwater surfaces, including rocks, plants, and docks. They’ve gradually spread westward attached to boats and other watercraft, taking over lake bottoms and washing up on beaches, their tiny shells as sharp as glass.
Boat inspection stations are now commonplace in Montana. Matson explained how water samples are also collected and analyzed from various lakes to detect mussel DNA. Scientists and state officials want to see them coming.
“That’s just one tool,” Matson told the crowd. “Dogs are another tool the state uses to try and find the mussels before they take over.”
Ismay, a 6-year-old black lab, made her entrance accompanied by her owner, Deb Tiermenstein, who explained dogs can detect even the smallest scent of mussel from a source that doesn’t contain any actual mussel DNA. The mussels are such a threat that trainers are not allowed to use actual mussels in working with their dogs.
Ismay waited eagerly by the trees while Tiermenstein invited the group to gather around a boat that had been staged for the demonstration. Kids rushed forward to tell her where to hide a tiny vial of mussel scent in a nook on the back of the boat. When Ismay was released and summoned, it took her less than 10 seconds to identify exactly where the mussel scent was coming from. She barked loudly and was immediately rewarded with treats and applause.
Not far away, another crowd gathered to see two small white submarines that had come for a week of scientific exploration in Flathead Lake.
Submarine owners Cliff Redus and Hank Pronk are members of Innerspace Science, a group that connects private owners of submersibles with scientists and educators.
Redus’ R-300 is a one-person sub. Pronk’s Nekton Gamma accommodates two, as long as the second person is under 250 pounds and is small enough to hunch cross-legged in the small space behind the sub’s front viewing dome.
Research divers in Flathead Lake generally stay above 8 meters during the summer. That’s about the point where the warmer, less dense water meets the colder, more dense water below. The divide between the two layers is called the thermocline.
“It’s cold down there,” said Jim Craft, a bio station ecologist who has been studying Flathead Lake since 1988. “It’s no fun for a diver to go below the thermocline.”
After their first dive in Flathead Lake, Redus and Pronk told Craft they could see heat waves coming off the thermocline the way you see them rise from the highway in the dead of summer.
“They can see things down there that we can’t see otherwise,” Craft said. “They’ve got big lights on their submarines. I want to know what’s down there.”
Craft was especially interested in finding out more about what’s happening with invasive species, such as Mysis shrimp, below the thermocline. He also wanted to analyze plants, sediment and algae samples from deeper waters.
The Mysis shrimp don’t like warm water. They stay at the bottom of the lake during the day. It’s presumed that they only come up to feed as far as the thermocline at night, possibly dashing up and back to snatch tempting morsels from the warmer waters above.
These are things you can’t verify simply by taking water samples in the dead of night, Craft said. You need submarines that can capture video and images of the water column while the shrimp are active.
At the open house, Redus leaned over from above and helped a long line of wide-eyed children and a few sheepish adults climb in and out of his submarine for a few seconds of deep-sea fantasy.
Pronk watched from the doorway with a satisfied grin on his face as visitors got up close and personal with the submarines. He’s been building or renovating subs since he was a teenager and has five more at home. Sharing them with others is his favorite thing.
Sean Stevenson stood nearby and watched with a similarly pleased expression. Stevenson is one of the divers who accompanies the submarine crew on these excursions, standing by to rescue them if something goes wrong. He used to be a rescue specialist with the Canadian Coast Guard.
Because Stevenson can only dive to about 250 feet, that’s about as low as the submarines will go as well. The lowest point in Flathead Lake is about 100 feet deeper than that, but the submersible explorers saw plenty. In addition to taking extensive photos and videos, they gathered water samples and vacuumed up sediment using a robotic arm on the Nekton Gamma. Those samples will be analyzed over the next couple of months.
Conna Bond is a local science writer and a student in the environmental science and natural resources journalism master’s program at the University of Montana. She worked this summer as an environmental journalism intern at the bio station.