SITES is mapping lake sediments for the lakes included in the thematic programmes SITES Water and SITES AquaNet, to enable a better understanding of biogeochemical processes within the lakes. The latest lake investigated was Lake Erken.

In most lakes, a sub-bottom profiler, using acoustic signals of different wavelengths to produce images showing bottom surface, sediment layers and underlying bedrock, has been employed. In addition, sediment cores have been collected across the lake as well as at targeted areas near the greenhouse gas (GHG) chamber locations (Layer 6 in SITES Water).

For a breath of fresh air and due to the continuing pandemic, this year’s version of the annual Krycklan symposium was outdoors the full day. Fresh air it was announced beforehand and fresh air it sure was – it came in gusts and with tiny drops of water in it. Despite the weather conditions, the mood among the ca. 30 participants was overall very good.

The Krycklan symposium brings together people involved in the Krycklan Catchment Study and other interested researchers to hear more about the activities taking place in the catchment, and to gain insight into the most recent research.

Krycklan is an integral part of the Svartberget field research infrastructure. The 6780 ha Krycklan catchment study of today, an expansion of the original 50 ha at Nyänget in the 1980’s, is one of the most instrumented and monitored watersheds in the world. The expanded scope of research includes mercury, weathering, aluminium, carbon cycling, water uptake by trees and connection between soils and surface waters. The overall aim is to create a process-based understanding of the regulation of stream water chemistry.

Tarfala Research Station personnel have been busy this summer measuring the Tarfalajokk discharge.

Wide-spread mass loss from the glaciers in the Tarfala valley this summer, together with some impressive rainfall events, has made Tarfalajokk almost double in size. Continuous measurements throughout the summer, using a fluorescein tracer dye, have been conducted and it is now soon time to go back to Stockholm to analyse the data.

Stream discharge data from Tarfala can be found in SITES Data Portal.

Have you ever wondered about the invisible bacteria, archaea, viruses and protozoa hiding in our lakes? Each drop of water contains millions of unicellular organisms that cannot be seen with the naked eye, and in order to map and describe the diversity and function of these organisms, we need to use new methods based on their genomic information.
 
In the project called "PELAGICS" (Pan-European Lake Sampling - Microbial Eco-genomics), an international group of researchers use new genetic methods to map freshwater microbial diversity on a European scale. Under the leadership of Michaela Salcher and Rohit Ghai, both from the Czech Republic, 70 large lakes, located in 16 European countries, will be sampled for both bacteria and protozoa. The samples will be used to isolate cultures of bacteria and protozoa, that will be analysed using cultivation methods, and, furthermore, sequencing of the total microorganism genome (metagenomics) will be done.
 
The most recent country visited by the PELAGICS sampling team was Sweden, where researchers collected bacterial samples from Lakes Mälaren, Erken, Vänern, Vättern and Torneträsk. By establishing a collaboration with the SITES Research Stations Abisko and Erken, as well as county administrative boards and the tourism industry, sampling efforts have been organized efficiently and safely and a broader collaboration formed.
 
The project will produce a large amount of sequencing data (20 Tb) in the coming months, and researchers hope that the data will help answer several challenging questions, such as, which organisms make up the freshwater microflora and their distribution in Europe.  The researchers also hope to answer more general questions concerning species formation of microorganisms and local evolutionary adaptations.
 
For the Swedish part of PELAGICS, Professor Stefan Bertilsson (SITES Director/SLU), Dr. Matthias Hoetzinger (SLU) and Professor Silke Langenheder (Uppsala University) are participating.