Time for another update as I near the end of my internship at NORCE LFI with over 100 hours under my belt. As you are all well aware from my last blog entry’s exciting cliffhanger, I went down to Rysstad to assist in some field work carried out in the Otra river as part of the SUPERSAT project.
I drove down to Rysstad together with Sebastian from LFI, and upon arrival at the ‘research cabin’ we met two more researchers from NIVA, Oslo, who were there to assess the bulbous rush (Juncus Bulbosus) in the Otra river. The following morning Sebastian and I got straight to work with monitoring and setting up new gas loggers along the river. These devices are submerged in water and measure the percentage of gas supersaturation. They are of special importance in the Otra river as there are hydropower plants and dams built here, which can have major impacts on the supersaturation levels in the river, with levels up to 170% having been measured in the Otra. Gas supersaturation levels of 109% are already enough to cause lethal effects in some organisms (Pulg et al., 2018. Gassovermetning i vassdrag – en kunnskapsoppsummering), which is why it is critical to shed some more light on the effects of natural and artificial gas supersaturation occurrences in Norway’s waterways.
Another task in Rysstad was to set up acoustic receivers along the river followed by catching trout and tagging them with acoustic transmitters, to be able to track the fish’ response during exposure to high levels of supersaturation. Here, the J. Bulbosus posed a challenge as it was present in such dense growths that it interfered with the acoustic signaling. The trout were even suspected to occasionally take shelter underneath the dense J. Bulbosus, making it difficult to track them. We used an underwater drone to make additional attempts of locating the fish. I had intended to continue helping out with the vegetational challenges and remaining parts field work the following week, however this was cancelled last-minute due to the national regulations brought on by the COVID-19 pandemic.
I have since been at home with my family and continued my internship and university studies online, as many other students around the world are also currently experiencing. I was lucky enough to be able to continue with the SUPERSAT project from my ‘home office’ and am now gathering data on 2000 of Norway’s hydropower stations including their turbine types and noting which bodies of water their outlet releases into. Fun fact: Øvre Forsland Power Station, deemed “The most beautiful hydropower plant in the world” (Helgeland Kraft, 2016. Øvre Forsland kraftverk), was designed by my cousin!
This time at home has provided a good opportunity to read some more articles and gain deeper understanding about the effects of gas supersaturation in freshwater systems, and just how big of a role hydropower plays in raising the percentages. Norway has one of the highest electricity consumptions per capita in the world, and over 95% of Norway’s electricity production comes from hydropower (NVE, 2015. Energibruk, -effektivisering og teknologier). The biological consequences concerned in this study have been of great interest to me since I heard of the project, as many years of recreational diving have made me well aware of just how severe decompression sickness (caused by dissolved gases) can be.
Stay tuned for my next and final blog entry where I sum up my experience at NORCE LFI for this semester!