Dark water in Bergen? Investigating the elements in Store Lungegårdsvannet and Puddefjorden Part 2


This semester is finally over, and my project has come to an end. I can’t begin to describe how grateful I am for all the things I have learnt the past months, from planning a research and executing the steps, to communicating the science to an audience and passing a meaningful message. Everything I learnt made me a better scientist, a better person. So, while I still have the attention from most readers, I would like to thank my supervisors, Jorun Karin Egge and Tatiana Margo Tsagaraki for guiding, teaching, and supporting me whenever I needed it throughout these months. Secondly, I owe a huge thanks to the coordinators of the BIO299 course, Vigdis and Dagmar for making this course possible for the students and providing food for thought through our discussions.

Figure 1. My supervisor Jorun Karin Egge, demonstrating the sampling method. Thank you for accompanying me every morning at the docks and for telling me all about the history of the area!

And now its time to reveal the results of the study! In my previous blog, I provided some background about the study area and explained why it became the inspiration of this project.  Heavy metal pollution due to anthropogenic influence is posing a severe threat to aquatic environments, especially in urban coastal areas of high value. The project Cleaner Harbor Bergen suggested by the experts in Bergen municipality was implemented as a strategy against these environmental problems in the surrounding coastal areas of Bergen. Under that scope, the aim of my study was to investigate the elemental composition and impact of heavy metals on phytoplankton biomass in Puddefjorden (PUD) and Store Lungegårdsvannet (SLV), in Bergen, during spring 2021. C, N, P, Ca, Si, Mg, K, S, Fe, Mn, Cu, Hg, Pb, and As were counted through Wavelength dispersive X- ray fluorescence spectroscopy in combination with documenting chlorophyll a concentration.

Figure 2. Up: Puddefjorden and Store Lungegårdsvann view from Ulriken  in 1910. Photograph by C. A. Erichsen part of the archive of architect Einar Oscar Schou, Bergen City Archive. Down: View of Bergen city from Ulriken on the 16th of April 2021. Photograph by Barbara Kaudela.

The results revealed that that a phytoplankton bloom took place on the 18th of March 2021, coinciding with Si values marking a 42%(in Puddefjorden) & 50%(in Store Lungegårdsvannet) increase, indicating that the phytoplankton community was dominated by diatoms. Particulate concentration of Mn and Cu and relative numbers of, Hg, Pb, and As were rather low and did not appear to fluctuate in relation to the changes of the phytoplankton biomass, thus suggesting that these elements did not appear to be incorporated into the phytoplankton biomass during the investigation period. Some elements like Fe appeared to be in higher levels than it is usually common for Norwegian fjords. Overall, the levels of heavy metals were higher in Store Lungegårdsvannet than in Puddefjorden. However, to know more about the sources of these chemical elements that accumulate into these areas is a study subject for the future. The findings of this study contributed to the further understanding of the complex abiotic (chemical elements) – biotic (phytoplankton) relationships in the coastal ecosystem of Bergen. Hopefully, this approach of incorporating biotic components into abiotic assessment studies and understanding more about their interaction will help choose better monitoring plans for battling environmental pollution.

In conclusion, it is very encouraging to see that the competent bodies of the municipality not only acknowledged the problem of years and years of urban pollution but actually took action to change the situation and protect the aquatic environment of these coastal ecosystems. However, careful future monitoring is the key to future success.I hope you enjoyed reading my blog and I would like to thank you for doing so! If you are interested in taking a look at the poster I made you can follow this link! Bye 😊

Figure 3. Me sampling with the water sampler at Store Lungegårdsvannet. Photograph by Jorun Karin Egge.

 

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