HIDDEN 01

HIDDEN is a joint project between Swedish (Lst Västerbotten, Lst Norrbotten, Sveriges geologiska undersökning – SGU) and Finnish (Luke, Economic Development Centre of Northern Finland, GTK) partners. The project focuses on the ecological status of different types of river estuaries in the Kvarken and Bothnian Bay regions of Finland and Sweden.

Luke’s work package includes: (1) assessing suitable conditions and habitats for the development of European whitefish eggs across different types of river estuaries, and (2) mapping northern pike breeding areas in river estuaries and adjacent coastal zones. The whitefish egg incubation experiment will identify key environmental conditions affecting reproduction, including exposure, eutrophication levels, and land use. The data on pike larvae will be expanded by integrating with existing datasets compiled by Luke. This combined dataset will then be used to model pike breeding habitats across the Gulf of Bothnia. While the previous modelling efforts by Luke have been widely applied in decision-making, this data, particularly for the northern pike, are outdated and almost absent for the northern Gulf of Bothnia. The work package will therefore address important knowledge gaps.

Both fish-related subprojects are linked to broader investigations of eutrophication and climate change impacts along the northern Baltic Sea coast. Data generated in other project work packages will also support Luke’s research. Together, these efforts will provide a strong scientific basis for decision-making, fisheries management, and environmental impact assessments. The work is also connected to other ongoing Luke projects (e.g. NiittyHOI, Biodivesea) and will further strengthen collaboration between Finnish and Swedish partners.