The Interreg Aurora funded project SealHabitat develops new tools for ringed seal monitoring.
Hydrophones are underwater microphones designed to record acoustic signals of water ecosystems. They are vital tools for capturing a wide range of sounds including marine mammals and underwater noise.
In the northern part of Lake Saimaa, University of Eastern Finland is responsible of setting hydrophones to collect evidence of seal presence and thus their habitat use. The hydrophones were set during the winter 2026 and collected early summer. Currently, data is being analyzed, and the project staff hope to hear some seal sounds that reveals wintering seals in these edge areas of seal distribution in Lake Saimaa.
Hydrophones were collected in early summer in Lake Saimaa
The project partner Turku University of Applied Sciences has the main responsibility in collecting underwater vocalizations of ringed seals and soundscape of their habitats in the Bothnian Bay. In December 2025 the first set of hydrophones was deployed to locations with expected ringed seal activity in their breeding and moulting seasons. Moulting season is the annual period when seals come onto land or ice to shed and regrow their entire fur coat. In late June 2026 these hydrophones were retrieved and new ones were deployed for foraging season in summer and autumn. Next step is to examine the collected data, which will keep the staff busy during the coming months.
Collecting underwater vocalizations of Baltic ringed seals in the Bothnian bay
Before the ice break-up in Bothnia bay the third project partner, the Swedish Museum of Natural History conducted the annual ringed seal survey during the moult. The survey is conducted as part of the national monitoring program funded by Swedish Agency for Marine and Water Management, but the results are integrated into the SealHabitat project.
Spring brought on challenges with technology when the telemetry tags for the ringed seals did not perform as expected. After some trouble shooting new tags were ordered and planning for autumn fieldwork is underway. Otherwise the spring and the summer has been spent with some intense work in front of the computer, cleaning and processing previously collected GPS telemetry data and creating a species distribution model; this involves predicating pseudo-absences based on the seals at-sea trips, extracting environmental variables and finally training a machine learning model. This can then be applied to future climate scenarios.
Planning line-transects during the annual ringed seal moult survey
Learn more about the project SealHabitat
