In September 2024, the North Pole-42 expedition went on a voyage across the Arctic. Among the 34 researchers on board the ship was an employee of Tomsk State University – Vasily Leontyev, an engineer at the Laboratory of Radiophysical and Optical Methods for Studying the Environment. He brought the equipment specially developed by laboratory specialists to the North Pole to study Arctic plankton under water. The expedition will last until 2026, but part of the team, including Vasily Leontyev, returned home in April according to the planned rotation.

Since the Laboratory of Radiophysical and Optical Methods for Studying the Environment of TSU has long been studying a wide variety of particles in the aquatic environment, at some point there was a need for appropriate equipment. Who else but the scientists themselves know what exactly they need and what parameters the equipment should have? So Tomsk engineers, by trial, error and refinement, created an underwater digital holographic camera, information from which is transmitted via communication lines. It uses a special software to process the received data.

— Our equipment allows studying plankton directly in the habitat: register a hologram of the water volume at a given depth, then transfer it to a ship or to land and reconstruct the volume image in layers using a software. This research method makes it possible to understand the exact coordinates of the place of a particular particle or plankton individual. The software allows determining sizes and shapes and recognizing all this automatically. Most importantly, we do not disturb the environment, – said Victor Dyomin, First Vice-Rector of TSU, head of the Laboratory of Radiophysical and Optical Methods for Studying the Environment.

Besides, Tomsk equipment allows registering the largest volume per one exposure. The larger the volume, the more studied particles get there. So scientists can make more accurate and complete measurements.

— The principle of holography is two waves: everything that scatters on particles is an informational, objective wave; all that passes along particles is a reference wave. They interfere with each other, and we register this interference pattern, – explains Victor Dyomin.

Two holographic cameras were sent to the North Pole. One worked through a hundred-meter cable and fiber optic, the second was battery operated.

Within 26 minutes, the camera takes measurements in different modes, then the remaining two hours it reconstructs the holograms. At the end of the duty, an engineer takes the processed information to view on the computer. As a result of a three-day observation, the engineer had to look at almost five thousand pictures. The task was to sel ect and store separately the materials with plankton individuals for further study, indicating the parameters of the place, time, temperature and other things.

— Once, looking through the photos, I saw that one animal is somehow different. I sent the picture to Igor Polovtsev (senior researcher at the Laboratory of Radiophysical and Optical Methods for Studying the Environment), and he replied that such animals should not be found there, they are characteristic of the Barents Sea, but, apparently, some currents brought them here, – said Vasily Leontyev.

Vasily Leontyev worked in a hydrobiological unit, and it was important to build the observation mode so as not to intersect with oceanologists – their equipment had minus 42 volts, plus circulating currents around the ship itself, which in combination could not so much affect the result as harm the equipment itself. Despite the fact that Vasily Leontyev did not design the equipment (the main developer is Igor Polovtsev), but due to its continuous work on a ship, he knows the device quite well.

— On average, says Vasily Leontyev, in an ordinary reservoir, ten days are enough to understand the behavior of zooplankton. We were here fr om October to April, and this is daily duty, scanning, calibration. So, both sets performed their functions perfectly.

Now all the obtained data is processed on the mainland. This is done by the chief equipment designer Igor Polovtsev and data processing specialist Alexandra Davydova, an employee of TSU in Krasnodar, who worked with Vasily Leontyev. Moreover, as Vasily Leontyev added, they prepared three articles for publication according to the results of the expedition.