As bubbles rippled across a frozen lake in Finland, divers in a polar scientific diving course practiced descending beneath ice to reach the seafloor—an environment scientists say remains difficult to study as climate change accelerates melting and reshapes polar ecosystems. In this month’s session at the Kilpisjärvi Biological Station, diver Daan Jacobs emerged after a 45-minute dive, having traveled 8 meters (26 feet) under the ice in conditions where land temperatures approach minus 40 degrees Celsius and Fahrenheit.
The course is designed by the Finnish Scientific Diving Academy to help train the next generation of scientists and researchers to dive beneath Arctic and Antarctic ice, so they can study organisms living along the seafloor with little to no sunlight. Organizers said the work matters because the Arctic is warming faster than the rest of the planet, and they point to impacts that reach beyond the polar region, including changes linked to sea ice that polar bears rely on for hunting. In Antarctica, they say warming is contributing to melting ice sheets, which in turn drives sea level rise and disrupts ocean ecosystems.
During training, divers learn what it takes to operate in extreme cold from the surface and to work safely underwater. In the Finnish winter, snow blankets the ice and whipping winds sweep across Lake Kilpisjärvi, creating risk for the topside support team that must operate equipment while fending off frostbite. Participants also train as safety divers, including how to respond if the primary diver cannot locate the hole in the ice to surface after 45 minutes below.
Jacobs, who serves as a biodiversity adviser in the Netherlands, said the conditions underwater were striking, describing the view as “beautiful” as he surfaced and gulped for air. In his dive, he reached a section where sunlight filtered through the ice and fish swam around a rock formation. He took part in a Polar Scientific Diving class earlier this month, which the academy designed to produce researchers capable of collecting data and specimens in the polar environment.
The academy’s instructors also framed the course as a response to a widening research gap. Marine biologist Erik Wurz, one of the class’s instructors, said “Because it is melting so fast, we need to have more people deployed there — more science to be done — to understand better what happens,” adding that they needed to work quickly to save a “unique ecosystem” in both the Arctic and Antarctica. Organizers said only a few hundred people worldwide currently have the specialized scuba diving skills and scientific training needed for this kind of underwater fieldwork.
Simon Morley, a marine biologist with the British Antarctic Survey who was not part of the course, said human presence remains necessary even as scientists increasingly use artificial intelligence and robots. He said dragging nets across the seafloor would destroy habitat, and that remotely operated submersibles or robots typically can collect only one specimen at a time. Morley added that “A diver can go down and pick up 12 urchins, put them in a bag and not affect the rest of the system,” describing the advantage of targeted collection.
The program runs as a 10-day session in a location designed for training: instructors drill divers on a frozen lake at the University of Helsinki’s Kilpisjärvi Biological Station. The academy says the program began in 2024, and demand has allowed it to add a second session each year. Participants come from a range of backgrounds, from marine and freshwater biologists and other scientists to highly skilled recreational divers and documentary filmmakers.
Two students described their motivations and what they learned during this month’s practice. Ruari Buijs, a marine biology and oceanography student at the University of Plymouth in England, said he enrolled in the class as “a very good stepping stone toward that goal,” aiming to work in Antarctica and study marine megafauna. Caroline Chen, a scientific diver and research assistant in Germany, said it is her dream to dive in the polar regions and that the course would help her design future experiments for such “challenging conditions.”
Divers said the course goes beyond simply learning to breathe and move beneath ice. They practice diving through ice that can be nearly a meter thick and working in water temperatures hovering just above freezing. Chen said it was “insane from the bottom up,” describing how she saw sunlight stream through the ice in a way that appeared to mimic another Arctic phenomenon. Buijs said the cold does not affect covered parts of a diver’s body, but he described how the area around a diver’s mouth remains exposed underwater, saying he thinks “the worst thing is like your lips feel very numb afterward and they like stick out a lot,” and joking that “You kind of get Botox lips a little bit.”