Researchers to Listen to Clicks to Protect Endangered Baltic Porpoises

A new research project aims to bolster scientific understanding and protection efforts for the critically endangered porpoise population in the inner Baltic Sea and the Belt Sea. The project, named Conservation Union for Management of the Baltic Harbour Porpoise Populations and their Habitat (Cumbiah), will gather and develop new knowledge about the porpoises' numbers, the threats they face, and their habitats.

Signe Sveegaard, a senior advisor and project leader at Aarhus University, stated that porpoises in these regions are exposed to human-induced threats. "Limited protection measures have been implemented so far," she noted. "Therefore, we want to create a solid knowledge base that can support effective management in the future."

Central to the project is the analysis of acoustic data collected in 2024 and 2025. This data, comprising measurements and descriptions of the click sounds porpoises use for navigation and foraging, will be recorded using underwater microphones. Researchers will use this information to gain a better understanding of current population sizes, trends, distribution, and density.

The project will also investigate human activities in the marine environment. Measurements of underwater noise from construction projects and seismic surveys will be correlated with porpoise distribution and density. This will help identify areas where porpoises are particularly vulnerable and may require specific protective measures. Cumbiah includes 14 partners from Denmark, Germany, Sweden, Estonia, Finland, and Lithuania, with funding provided by the German Federal Ministry for the Environment.