The city is using untreated spruce trees from the winter's spruce forest at Melkertorget in Västerås and from a Christmas tree cultivation outside Västerfärnebo. According to officials, the trees are being sunk to the lake bottom to form favorable environments for fish such as perch and roach. This ecological approach has already been implemented in some other locations around the lake.
Johan Axnér, water coordinator at Västerås city, explained the benefits of the initiative. According to SVT Västmanland, Axnér described how the dumping helps fish by creating better structures on the bottom that attract fish and insects, adding value around the Östra Holmen reserve. He noted that while there are large parts of Lake Mälaren with plenty of dead wood and vegetation in the water, this project specifically enhances the reserve area.
The exact number of Christmas trees being dumped and the project's complete timeline remain unspecified. It is also unclear what additional fish species beyond perch and roach might benefit from the initiative, or whether there are any environmental risks associated with dumping trees into the lake. The effectiveness of this method in other implementation areas has not been detailed by officials.