Field activities in WP.3.3 - beaver dams
Beaver dam removals and ditch cleaning has been carried out at some demo areas and the monitoring of mercury (Me-Hg and/or tot-Hg) in water, sediments and biota continues.
The monitoring of general water chemistry and tot-Hg in biota samples in beaver- and ditching demo areas in in Latvia, Sweden, Poland, Lithuania and Finland has been performed in 2017 as it was done in 2016. See WAMBAF Newsletter 2 for details.
Samples from shredders
One difference in 2017 compared to 2016 is that animals in the functional feeding group (FFG) “shredders” have also been collected, in addition to animals from the functional feeding groups “grazers/scrapers”, “filter feeders” and “predators” (fish).
From all demo areas either isopods (Asellus sp.) or amphipods (Gammaridae sp.) were collected in June, and also during September-October in the demo areas where the 4th sampling has been carried out this far.
Sediment samples from all countries
In 2017 we have also collected sediment samples for tot-Hg and Me-Hg analysis, see figure 1 for details, at the beaver demo areas in
- Latvia - June and October
- Sweden - June
- Poland - June
- Lithuania - June and October
We have also collected water samples for tot-Hg and Me-Hg analysis at the aforementioned beaver demo areas as well as in the ditching demo areas in Sweden in June and in Finland during June and September.
Before and after removal
From the Latvian beaver demo area pictures are provided from before, during and after the beaver dam removal, see figures 2, 3 and 4.
//Joel Segersten, SLU