https://doi.pangaea.de/10.1594/PANGAEA.995125Taupp, ThomasThomasTaupp0000-0002-4488-582XFederal Institute of HydrologyGmeiner, IsabellIsabellGmeiner0009-0003-6936-980XFederal Institute of HydrologyMichel, LucieLucieMichel0000-0002-5516-4630Federal Institute of HydrologyAvila, Isabel CristinaIsabel CristinaAvila0000-0003-1389-8908Stiftung Tierärztliche Hochschule Hannover, Klinik für kleine HaustiereNachtsheim, Dominik AndreDominik AndreNachtsheim0000-0002-1010-3527Stiftung Tierärztliche Hochschule Hannover, Klinik für kleine HaustiereSiebert, UrsulaUrsulaSiebert0000-0002-2556-3948Stiftung Tierärztliche Hochschule Hannover, Klinik für kleine HaustiereWinkelmann, CarolaCarolaWinkelmann0000-0002-3797-8454Federal Institute of HydrologyPANGAEA2026Aerial surveyElbe EstuaryGrey sealHalichoerus grypusHarbour sealMonitoring reportPhoca vitulinaEvent labelDATE/TIMELATITUDELONGITUDEPhoca vitulina, adultPhoca vitulina, juvenilHalichoerus grypusAircraftCounting, visual2023-08-16T00:00:00/2024-07-08T00:00:00Dataset10.5675/BfG-22411911 data pointstext/tab-separated-valuesCreative Commons Attribution 4.0 InternationalAerial surveys were conducted in the Elbe Estuary, Germany, to count seals on their haul-out sites. Haul-out sites were located within the intertidal zone, usually close to the waterway or tidal creeks. The north-western border of the study area was located at the approximate river-km 753 (island of Scharhörn) and the south-eastern border was located at river-km 632 (Mühlenberger Loch). Flights were performed monthly from August 2023 until July 2024 (11 flights in total) at low tide. Within each month, a flight date in the middle of the month was chosen, depending on the tide and weather conditions. The flight scheduled for December 2023 had to be canceled due to persistently unfavorable weather conditions. Flights were performed with a twin-engined aircraft at a height of approximately 500 feet and at an average speed of 100 knots. The flight routes were tracked via GPS. Sighted seals were photographed on their haul-out sites and the corresponding geographic position was recorded. In the office, the photos were used to identify the species and age class, and count the animals.8.373650189.81401833353.5492891953.99521859