Do restored wetlands contribute to elevated methylmercury in water? (Master)

Last changed: 16 February 2022

This project aims to evaluate if restauration of wetlands will cause elevated concentrations of methylmercury in runoff water, and if so, in what kind of environments the risk is high respective low for elevated metylmercury formation.

Restoration of drained wetlands is encouraged politically to increase biodiversity, reduce the risk of floods and droughts, and increase carbon retention. However, restoring wetlands may also increase the risk of elevated formation of toxic and bioavailable methylmercury. Methylmercury biomagnifies in food webs and almost all inland waters in Sweden have fish with levels of mercury that greatly exceed the threshold value in the EU Water Framework Directive for good ecological status. Therefore, knowledge is needed about which types of wetlands that pose the greatest risk of elevated concentrations of methylmercury in the water when they are restored.

In this project, we will sample water from about 30 recently restored wetlands and compare with as many historically drained wetlands that have not been restored. The wetlands span a gradient in climate, soil conditions and vegetation, from Småland in the south to Norrbotten in the north.

The work starts at the end of May 2022 with about 4 weeks in the field, when wetlands are identified and sampled. If you do not have the opportunity to start in June, get in touch and we will discuss possible arrangements. In this project, it is possible to collaborate with a dissertation colleague who focuses on mercury in the same wetlands (see the ad Does restoration of wetlands help to counteract the browning of lakes and streams?).

The thesis should be written in English. Supervisor is Karin Eklöf at the Department of Aquatic Sciences and Assessment.


  • Main subject area: Environmental science
  • Level and length: advanced level (Master, 30 hp / 20 weeks)
  • Language: English