We continue with the batymetry measurements in the wetlands. Now we have done more than 50 % of the 112 wetlands.

Today, some results from our survey to landowners were in the “science news” segment on Swedish national radio. It was the fact that the most common use of the constructed wetlands, by the landowners, was skating. Almost 40 % of the landowners we interviewed stated that they used the wetlands for skating. The short news segment can be heard here (in swedish): https://sverigesradio.se/artikel/bonder-aker-skridskor-i-vatmarkerna

During the weekend the 29-30 of January the storm Malik hit the westcoast of Sweden. Thanks to our water level meters located in 11 streams, we could follow the effect the storm had on the water levels, hour for hour. The data from the stream Trönningeån shows that between 02.00 and 21.30 the 29th of January the water level increased with 1.37 m!

As always with electronic equipment permanently deployed in the field there is some wear and tear. Here is a meter where the cable has been disconected, possibly beacause of movements of the ice. Sofia and Sam exchange batteries and repair the ones that malfunction continously.

Today Johan and Joel from Heurgren Film AB spent a day in Halland to film our activities in the buffer project and also visiting researchers Pia and Joachim from projekt WetKit. The film is produced as part of project WetKit.

This week the second field sampling was done in 80 of “our” buffer wetlands to investigate occurence of Cyano algae and cyano toxin, as part of our networking collaboration with Pablo Urrutia Cordero at Lund univiserity. This time it was Sam (working for Pablo) who did the field work.

This week Pia and Joachim from project WetKit have been in Halland for fieldwork in “our” wetlands. Colaboration is always rewarding and we hade good discussions on methods and the state of the wetlands. Pia and Joachim sampled sediment cores in 19 of the wetlands.

During our dragonfly surveys we found a Common winter damselfly (Sympecma fusca) at the wetland TA25. It is not rare in Sweden but have an easterly distribution and before our observation it had only been reorded once in Halland (in 2012) .

We have now done the first flow measurements in the 11 streams at the same segments where we have the flowmeters located. These first measurements were done at low flow situations (low water levels), and we will repeat this under medium and high flows also, to get good data on the flow at different water levels. Then we get data on flow with 1 hours resolution by combining the flow measure data with the water level data. The photos show some of the field work in the different streams.

We have added a categroy to our field protocols. When we are surveying the 112 wetlands (batymetry, dragonflies, invertebrates etc) we now also check for selected invasive species. We have selected ca 10 species that are easily recognized and invasive, in order to get data on the occurrence of invasive species in constrcted wetlands in the agricultural landscape. It was not planned in the proposal, but our field surveys give us a good opertunity to get useful data on a large set of constructed wetlands as a side-effect. The species we check for are e.g. Nuttalls Pondweed + Canadian pondweed (Elodea canadensis + C. nutallii), Signal crayfish (Pacifastacus leniusculus), Red water lily (Nymphae alba, var. rocea) , Grass karp (Ctenopharyngodon idella), Yellow scunk cabbage (Lysichiton americanus), Himalyan balsam (Impatiens glandulifera), Japanese knotweed (Reynoutria japonica/Fallopia japonica), Giant hogweed (Heracleum mantegazzianum). The photo show signal crayfish in the wetland D31.

We continue with the time consuming work of depth profiling all the 112 wetlands. The wetlands vary quite a lot in terms of vegetation cover and water depth. The photo shows one of the more overgrown wetlands (KA5). In this wetland was also found Robust spreadwing (L. dryas) during the dragonfly survey.

The dry weather has turned some wetlands into dry land. Theese extreme water level fluctuations are interesting for us to follow. Some species are adapted to theese habitats (shallow systems with occasional dryouts) and one example is the dragonfly Robust Spreadwing (Lestes dryas). The photos show the wetland “D10” in the dry state and some specimen of Robust spreadwing found during our dragonfly survey in that wetland. This species is relatively rare in Halland and it is likely that constructed wetlands that dryout during summer is of major importance for the species. At our survey we found a quite large population of L. dryas at the site. Another species found at D10, with similar habitat requirements, was yellow-winged darter (Sympetrum flaveolum). It is also a rare species (likely to be included in the next update of the Redlist). For theese habitats, the management is especially important as they are sensitive for overgrowing with reeds and trees. D10 is grazed and mowed.

Today Pablo Urrutia Cordero started his field sampling in 80 of our buffer wetlands to investigate occurence of Cyano algae and cyano toxins. We are networking together with Pablo to get synergistic effects from combining our projets.

We have started with the drone to test how efficient it is to get reliable data on emergent vegetation cover. The actual pgotography will be done in late summer when vegetation is at its peak, but we tested the drone today.

A professional film company (Heurgren Film AB) have spent two days following our work. In a project we network togwether with (WetKit) one part was to produce a film about constructed wetlands, and since we have several ongoing activities the film crew spent two days in Halland filming and interviewing us when we did our field work and discussed with the landowner.

Today we sent out the 3rd newsletter to the ca 8o landowenrs in the project with information about this years planned studies in their wetlands. Since we will take photos of all wetlands with a drone we also offered to send the pictures to the landowners if they wanted, which was quite popular.

By combining sonar data that we get from paddling with a SUP and sonar in the open water, with high resolution GPS-measurements from the shoreline and in high and dense vegetation in shallow water we get very good data on the depth and shape och the wetlands. The photos shows Sofia paddling with a sonar (left) and the photo to the right shows the position of the water depth data points from the sonar (blue) and the water depth data points from the GPS (white) From this we can construct very detailed depths curves of the wetlands.

This week we had a 2-day meeting with Jerker Jarsjö and Imenne Åhlén (Stockholm University), to decide methods to produce bathymetric maps of the 110 wetlands and to finalise our strategy for flow measurements in the 11 streams in our joint project. It was a very productive meeting and the photos show equipment testing and part of the field work including trial with a remote-controlled boat with a sonar to map the wetland topography (bathymetry).

The collection of invertebrates last summer continues to reveal interesting findings as the experts go through the material. The latest interesting discovery regarding species biogeographical data was the spider Rugathodes instabilis that was found in one of our wetlands in Halland (see photo below). It has only been found with a handfull individuals at 4 sites in the counties of Uppland, Östergötland and Skåne before, and now also Halland! For more info: https://artfakta.se/artbestamning/taxon/rugathodes%20instabilis-101722

Naturvårdsverket (Swedish EPA) arrangerad an annual meeting for the 8 projects awarded in the call. We got presentations on the progress in the varius projects and also information from the SEPA, Formas and SGU. The image beloww shows a map of the location of all the water level meters from our project presentation. The presentation can be found here

The status report for our project is now submitted to Naturvårdsverket

We had to change batteries in two of the water level meters. It was a bit difficult due to a combination of ice and rain, but with a SUP and umbrella Lea and Sofia managed! Good work!

Today we sent out the second newsletter to all the landowners (> 80).

In August we did the third sampling campaign of invertebrates in 50 CWs, with Malaise-traps, colour pans, suction sampling, and pit fall traps. The picture shows insects collected by Malais-trap.