Work package 1
Process-oriented studies of catchment and in-lake Hg cycling
This work package is led by Heleen de Wit, and the main aim is to investigate factors driving catchment export and in-lake processing of Hg species to better assess catchment loading and future food web exposure to aqueous MeHg. A central theme in this work package is dissolved organic matter (DOM), which is a transport vehicle, a limiting factor for in-lake retention processes and a promoter of food web Hg exposure. We will use existing research infrastructure (long-term ecological research site Langtjern) and ‘intensive’ study sites (paired lake catchments), process-based models, laboratory studies and novel analytical methods.
Included in this work package are several tasks, including studies of:
- The quality of organic matter and its role for transport and bio-availability of Hg species;
- The role of photodemethylation in MeHg exposure;
- Past and future projections of catchment and lake Hg processing;
Time series of MeHg in aquatic zoobenthos and the link to process-based modelling.