1,500 Christmas trees sunk in Finnish lake boost aquatic life

Researchers from the Finnish Environment Institute submerged 1,500 spruce trees in Lake Saimaa in 2021 to test whether they could create habitat for aquatic organisms. Three years later, benthic animal numbers had risen tenfold and species diversity up to fivefold, with local fishermen reporting more fish. The trees also offered a potential use for discarded Christmas trees.