In our first blog we briefly mentioned the monthly water sampling program. This is the core fieldwork behind DAEMONS. Twelve waterbodies are sampled which cover the different land uses in the area (identified as key end members), and the four main rivers within the catchment are also sampled. In this blog we thought we’d give a tour of the sampling sites in virtual form so readers can get a feel for the area. The main catchment is that of the Anråse river. Within this are the three subcatchments of the rivers Rördalsån, Lerån, and Porsån. First up we have three headwater lakes: Stora Hästevatten North, Gaffeln and Svallesjön. Stora Hästevatten North and Gaffeln are both in the well-studied Gårdsjön catchment, which then drains into the Rördalsån. Svallesjön drains into the Lerån. Next we have three headwater streams draining forests: one each for each subcatchment. The forest stream that drains into the Rördalsån is named F1. A nondescript name, but aficionados of research into acidification may recognise it as the reference stream for the famous Gårdsjön roof experiment, where a huge plastic roof was used to cover the G1 subcatchment and prevent rain and throughfall (and therefore acid deposition) from reaching the ground. Two of the mire streams are in the Rördalsån subcatchment, and the third is in the Porsån subcatchment. There’s certainly no shortage of mires in the catchment, and so here we were rather spoiled for choice. In contrast to mire streams, finding headwater streams with a dominant agricultural influence was difficult, as most of the land is forest. One of the agricultural streams is in the Lerån subcatchment, whilst the two others are downstream of the confluence where the Rördalsån, Lerån, and Porsån meet and form the Anråse river. Finally, we have the three rivers of the subcatchments, and then a sampling site in the Anråse river just above the tidal limit before it flows into the Hake Fjord.
DAEMONS kicked off in early 2020, with the first field samples collected in the Anråse river catchment in January. Shortly afterwards the COVID-19 pandemic began, putting a temporary stop to sampling. Despite this, the first stakeholder meeting went ahead as planned on the 15th April, albeit in the virtual, rather than physical world. Present for the meeting were a small but diverse range of stakeholders, with representatives from:
Representing the DAEMONS project team were Filip Moldan, Sara Jutterström and Johanna Stadmark (IVL), Martyn Futter (SLU), and Sofia Hjalmarsson and Lars Johansson (DHI). The team gave an overview of the project, including the aims, scientific background and model simulations of the dispersion of solutes from the river mouth into the fjord system, before the preliminary data were presented from the January, February and March sampling campaigns. The monthly sampling sites cover a range of the main land uses (identified as key end members) present in the Anråse river catchment: agricultural streams, forest streams, mire streams, lakes and river outlets. Total phosphorus concentrations in January for the different lake and stream sampling sites. The two sites with the highest concentrations (LE1.5 and LE2) are agricultural streams. The stakeholder group provided feedback on the early results with particular discussion about high phosphorus levels in some streams: is this diffuse emission from agriculture, or coming from point sources such as septic tanks? A question to investigate in future, and one that could perhaps be answered with extra analyses (e.g. E.coli). There were also requests to include specific lakes in the large-scale synoptic sampling campaigns that are planned quarterly, and to ensure oxygen concentrations were measured. Useful local information was also provided about water treatment works, pumping stations and other relevant people to make contact with. All in all, a very productive first meeting.
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