ImproRivHab

Summary

The project focused on the Polish part of the bigger INTERREG ImproRivHab project. The main goal was to improve riverine habitats in tributaries of the Gowienica and Ina river catchment areas on the Polish side of the Oder Delta, specifically to create spawning grounds and improve water quality by integrating gravel substrate.

Improving riverine structures has multiple benefits for the Baltic Sea. Improved hydrological conditions and more natural habitats mitigate eutrophication by slowing down the water´s movement through the soil and in the river. It also improves conditions for migrating fish and spawning success, strengthening the populations. Gravel beds create spawning areas for e.g. salmon and trout and strengthen the Baltic populations, which are experiencing extensive habitat loss and population declines.

During the project six gravel prisms in Gowienica and Ina rivers were built, which has resulted in 45 ha of restored river habitats. Increased ecosystem function could be seen quickly by increased water levels, more naturally flowing river stretches and increased wetland health in the areas. Also, an additional sequence of prisms was constructed in Widzeńsko as a compensation to a planned fish pass which turned out not to be feasible. This increases the spawning possibilities for salmonids in all rivers.