New possibilities of krill-dependent indicator species monitoring – UAV survey in Subarea 48.1

Unmanned Aerial Vehicles specially adapted for operation in polar regions were used to study distribution and population size of three Pygoscelis penguin species on King George Island, Chabrier Rock and Penguin Island (Subarea 48.1) in three austral summer seasons (2014/15, 2015/16, 2016/17). During these three expeditions 32 successful photogrammetry missions (total distance 3963,42 km) were performed. The total flight time of the missions was 40 hours and 56 minutes. Flights covered the area of 34.51 km². Images were taken with digital SLR Canon 700D, Nikon D5100, Canon T5i 700D with a 35mm objective lens. Flights altitude at 350 – 550 m AGL (Above Ground Level) allowed images to be taken with a resolution GSD (ground sample distance) of 3-6 cm. Obtained images were used for the estimation of population size. Precision estimation of individuals’ count was based on the photo interpretation of high-resolution Red-Green-Blue and one Blue-Green-NIR imagery, as well as automatic interpretation using ImageJ software. In selected colonies a comparison with the results of measurements taken at the same time from the ground level were done. Obtained images enabled us to locate and estimate the number of nests of: Adélie, gentoo and chinstrap penguins. In total approx. 30 000 nests in twelve breeding colonies were identified in 2016. The use of UAV for monitoring of indicator species enabled data acquisition from areas inaccessible by ground methods. Results will support the basic knowledge about the population size and distribution of krill-depended indicator species in Subarea 48.1.