October 26, 2025
Scientists of KarRC RAS tested a new underwater acoustic system in freshwater bodies
A new underwater acoustic system was tested out in the field by specialists of the Laboratory of Fish and Aquatic Invertebrates Ecology, Institute of Biology KarRC RAS, during an expedition to Lake Syamozero in the summer 2025. The device was used to estimate the fish stocks, to determine the fish species composition, and to map the lake’s depths.
The underwater acoustic testing system consists of several components. One part – the projector, which emits an acoustic signal – is lowered into the water. As the vessel moves slowly along a transect, the signal is transformed, and the parameters are displayed on a computer. The system Yet, the main task for the scientists in using this underwater acoustic system was to determine the lake’s fish population. Other methods for monitoring and documenting fish numbers are by capturing or video observation. This system permits doing the surveys faster, covering different seasons and times, while avoiding the fishing permit procurement routine.

- A permit must be obtained to conduct fishing. There are scientific fishing quotas for each body of water, which involves extra paperwork. Using this device, the task is made easier and the research can be accomplished faster, - explained Doctor of Biology, Chief Researcher of the Laboratory for Fish and Aquatic Invertebrates Ecology of the Institute of Biology KarRC RAS, Director of the Institute of Biology KarRC RAS Nikolai Ilmast. He also stressed that to get the full picture, it’s best to combine the different methods, with acoustic sensing and ichthyological surveys, i.e. fish catches, complementing each other.

This software/hardware suite was designed by Promyslovaya Gidroakustika (Industrial Underwater Acoustics) company based in Petrozavodsk. Systems designed by this company have been in use around the country for several years.
Photos: Nikolai Milyanchuk