Perspectives – growing our knowledge

Pupils help researchers survey brown water

The water in Swedish lakes and rivers will now be analysed.

Researchers at Uppsala University are currently engaged in analysing water samples sent in by nearly 3,500 secondary school pupils. “We hope to learn more about potential threats to freshwater resources, both in Sweden and in the rest of the world,” says Professor Gesa Weyhenmeyer.

Professor Gesa Weyhenmeyer wants to
involve schoolchildren in her research.

Throughout the country, 240 secondary school classes began the autumn term by collecting samples of water from lakes and watercourses as part of the Brown Water research project. The project involves measuring the temperature and pH of the surface water and analysing whether there is any connection between the water’s colour and benthic fauna.

Gesa Weyhenmeyer, Professor of Limnology, is leading the project.
“A previous international study surveyed water colour across the globe,” says Weyhenmeyer. “The study showed that the world’s water is becoming increasingly browner, which, for example, has consequences for our drinking water. Another finding was that the lakes here in Sweden are warming up very quickly. That’s how I got the idea to involve the community in finding out more about the state of our water.”

The pupils have been equipped with experiment kits, which include thermometers, sinkers, test tubes, plastic trays for collecting water and benthic fauna, and litmus paper for measuring the water’s pH. The teachers received a teacher’s guide showing how they can integrate the project in different subjects or use it in independent laboratory lessons.
Anna Magnusson is a science teacher at Vasaskolan in Hedemora. Her class of 14-15-year-olds is one of five classes at the school taking part in the research project.
“We’ve incorporated the project into a wider theme in which we’re studying water in chemistry as well,” she says. “It fits in with the curriculum if the pupils can carry out experiments while they’re studying water.”

One of the watercourses they have taken samples from is Lake Hovran, which merges with the Dalälven River.
“The pupils find it exciting that they’re doing something ‘real’,” says Magnusson, “and the project offers a link between school and research. Of course, we also hope that it will increase the pupils’ interest in science.”
For Eva-Lotta Kvick, maths and science teacher at Vallhallaskolan in Oskarshamn, the project was an opportunity to take up a local issue.
“I signed my pupils up because I think it’s important to focus on water and raise awareness among the pupils about our water resources,” says Kvick. “Kalmar County has a water shortage, and has had one all summer, so this study is very relevant.”

At the Division of Limnology at the Department of Ecology and Genetics, Gesa Weyhenmeyer compares the data submitted by the pupils with previous measurements and modelled data for Swedish waters. If she discovers any interesting or unusual values among the pupils’ data, she will return to the sampling point.
“What would be really special is if the water were very brown,” she says. “I have about 150,000 water samples from all over Sweden collected in earlier studies to compare with. We might be sent test tubes containing something we’ve never seen before.”

If that happens, new samples will be taken by the Division of Analytical Chemistry at Uppsala University, for example.
“One of the questions we will be asking is whether this water sample is normal,” Weyhenmeyer says. “Does it occur in other places on the planet or are we going in a completely new direction?”
“What I also want to do is involve the pupils and make them aware of what the brown colour means, that it’s vital we look after our water. Simple things, like that 50 per cent of our drinking water is actually taken from surface water and high standards are required before we can drink it from the tap – it feels really important that everyone in our society is aware of these things.”



Brown Water

  • The research on water quality changes is being carried out under the framework of the Global Lake Ecological Observatory Network (GLEON). Of particular interest is the amount of organic carbon in the water, which is what causes the water’s brown colour.
  • A global study found that Lake Fräcksjön in Västergötland has shown the most rapid changes over the past 20 years in comparison with almost 300 other lakes across the globe. The study findings make it particularly interesting to document Sweden’s water. Because as much as half of Sweden’s population gets its water from lakes and rivers, this research is relevant for society as a whole.
  • At the end of the campaign, the researchers will report back to the pupils and then we can hopefully see what future threats exist for freshwater resources both in Sweden and in the rest of the world.