When a friend of his bought a boat in Stockholm in 2018, scuba enthusiast and social care worker Frederik Johansson dived under to check the hull and was shocked at the number of used lead batteries discarded by boat owners that littered the Swedish capital’s waterways. Working with volunteers, Johansson helped to set up Rena Malaren ("clean Lake Malaren" in Swedish), a group of scuba divers, including Johansson himself, who dive into the city’s lakes and waterways, pulling out potentially harmful waste and trash with the help of rope pullers on land.
