The Danish lakes have been contaminated for many years due to nitrogen supply from mainly agriculture and wastewater from the cities. Conditions generally improved up to about the mid-00s, partly because of the sewage treatment plants that handle the wastewater. Yet only about 0.7 percent of the country's over 120,000 lakes live up to the EU requirements that were set almost 20 years ago. For 30 years, a research project at Aarhus University has investigated how climate change may affect the Danish lakes in the future. The results have shown that the conditions of the contaminated lakes will get worse if the temperature rises and more rain comes. Slowly the lakes are at risk of being reduced to turbid and smelly water surfaces, and this can have negative consequences for nature's plants and animals but also for the Danes who are bound to the special but fragile lakes around the country. "It's both a nice, but also a scary place. When I dive down, I experience sides of myself that I don't meet on land." Says Ninna Kofod. Ninna has grown up near Fure lake, and today she works as a free diving instructor. She has been diving for ten years, and has trained herself to get deep into the lake and into her own mind. "It's an inexplicable fear of the darkness and the depths I encounter. It's a bit like in movies where there is an eerie background music, but also a tremendous calm, and it allows me to explore the fear I feel," Ninna explain. It is not only the depth of the lake and her own psyche that Ninna has gained insight into through diving. Something special happens when the people she teaches lose their foothold and face the fear. "If you just can't hold your breath anymore, you might notice something you don't do every day. It's not always super pretty or nice, but I'm grateful that people dare to let me in and let me hold their hands while they are afraid." Ninna says.