An environmental project in Göteborg, Sweden, has transformed discarded Christmas trees into underwater habitats for fish in Lake Sisjön. According to SVT Väst, the organization Sportfiskarna sank the trees two years ago to improve the aquatic environment for several fish species including perch, pikeperch, and pike.
The method, known as creating 'brush bundles' or 'risvasar,' has been used for a long time to create favorable environments for fish. The Christmas trees serve as both homes and playgrounds for the fish. Hans Lindqwist of Sportfiskarna Väst explained their motivation: "We work for the fish's best interest, because if there are no fish that are healthy and doing well in the water, then we can't fish either."
it feels like the brush bundle has had an effect there
Now, two years after the trees were placed on the lake bottom, Sportfiskarna is checking whether the fish seem to be thriving in their new homes using an underwater drone. On the drone footage, the fish initially appear absent, but suddenly a large, fine perch appears above the surface. Angler Tove Rosenberg observed, "It feels like the brush bundle has had an effect here."