V. A. Bizikov’s research while affiliated with All-Russian Research Institute Fisheries and Oceanography and other places

The aim of the research to assess the pup production in the harp seal population in the White Sea in 2023 and 2024. Methods. An aerial survey of marine mammals to assess the abundance of pups and adults of the White Sea harp seal population using unmanned aerial vehicles/drones (UAVs) was conducted over the areas of drifting ice in the White Sea. A multispectral technique was applied which consisted in simultaneous photographing of the sea surface done with a high-resolution photo-camera and an infrared (IR) camera. Aerial survey data (synchronized pairs of photo- and IR-images) were processed using the «Python» neural network with the «Yolo v4» module. An assessment of harp seal pup production was carried out using the method of discrete extrapolation. The harp seal population was calculated using cohort analysis takin into account of mortality by years. Novelty. Full-scale multispectral aerial survey using several UAVs simultaneously. Automatic processing of huge amounts of digital photographs in optical and infrared ranges using computer vision technologies to find and recognize animals in photographs. Result. The 2024 data provided a total number of the White Sea harp seal population of 141692 + 8696 newborn pups and a total harp seal population estimate of 1548840 individuals. The 2023 assessment pup production was lower and was estimated at 124645 + 20774 individuals. The distribution of harp seal pups on the drifting ice of the White Sea in the winter-spring period is determined mainly by the ice conditions and wind conditions. Interannual fluctuations in the number of harp seal pups are determined by the number of mature females participating in reproduction. Practical significance: the data obtained will be used to assess the size of the White Sea population of harp seals and to develop recommendations for its conservation and rational use.

The aim of this research was to assess the current abundance of the Caspian seal population on ice in the Russian part of the North Caspian using instrumental methods of aerial survey in the infrared and optical ranges using a manned aircraft and UAV. The main method of the research was a multispectral aerial survey, the essence of which is to survey seal haulouts synchronously in the infrared and optical ranges. In winter, 90% of all mature individuals gather on the ice substrate of the Northern Caspian for reproduction, lactation and mating and spend a significant part of their time outside the water, which greatly facilitates their detection and counting. The aerial survey was carried out in parallel from two types of aircraft — the La‑8 manned amphibious aircraft and unmanned aerial vehicles equipped with high-resolution cameras in optical and infrared modes, which ensure reliable registration of seals on ice. Novelty: the advantage of joint use of a manned aircraft and a UAV equipped with special photo and infrared equipment is noted. As a result of the research, the flights were carried out from February 20 to March 5, 2023 in the daytime in good visibility conditions at an altitude of 200 to 300 m. amounted to 19704 individuals, including 4062 puppies. The animals were located in the southeastern part of the ice cover near the air demarcation line between the Russian Federation and the Republic of Kazakhstan on the ice edge. An increase in the number of seals was recorded due to migrating individuals from Kazakhstan. Breeding of the Caspian seal in winter 2022/2023 proceeded in a satisfactory manner. During the flight, it was found that there were no fresh releases of seals on the coast of Dagestan. Separate old carcasses, partially torn to pieces, were registered only on the shores of the Agrakhan Peninsula. Practical value : the obtained data are needed to assess the current abundance of the Caspian seal population in the Caspian Sea.