Julia Giebichenstein

Blog entries:

Of Endings and New Beginnings

Arctic Island Isoltation

Nansen Legacy at Forskningstorget 2019

• Giebichenstein, Julia; Warner, Nicholas Alexander; Routti, Heli Anna Irmeli; Harju, Mikael; Varpe, Øystein & Gabrielsen, Geir Wing [Show all 7 contributors for this article] (2026). Accumulation patterns of polychlorinated alkanes in an Arctic marine food web. Environmental Research. ISSN 0013-9351. 299. doi: 10.1016/j.envres.2026.124360. Full text in Research Archive Show summary

  Polychlorinated alkanes (PCAs), otherwise known as chlorinated paraffins, are contaminants of emerging Arctic concern where our understanding of their occurrence and trophic transfer in Arctic food webs remains limited. To investigate biomagnification potential of PCAs, we analyzed short-chain PCAs: C10-C13 and medium-chain PCAs-C14-17 in three Arctic species: polar cod (Boreogadus saida), ringed seal (Pusa hispida), and polar bear (Ursus maritimus) and Subarctic capelin (Mallotus villosus) samples collected from the northern Barents Sea in 2017 and 2021. PCAs-C10-13 concentrations were low, but detectable in all species, while PCAs-C14-17 concentrations were mainly below detection limits in the mammals. PCAs did not biomagnify, as the lowest concentrations were found in polar bear (0.7 ng g−1 lw) and the highest in capelin (56.9 ng g−1 lw). The PCA homologue profiles were similar among Arctic species, with PCAs-C10-13 dominating in polar cod and marine mammals, which may suggest a contribution from long-range atmospheric transport. In contrast, PCAs-C14-17 were most abundant in the Subarctic capelin, likely reflecting a different exposure. Despite differing PCAs-C14-17 concentrations among the two fish species, their PCAs-C14-17 homologue profile was similar, indicating uniform global production trends. Subarctic capelin is increasingly being preyed upon by Arctic predators and may facilitate the biological transport of PCAs-C14-17 into Arctic ecosystems. These findings suggest that climate-driven shifts in species distribution may have the potential to alter contaminant exposure pathways in Arctic marine food webs.

• Giebichenstein, Julia; Andersen, Tom; Varpe, Øystein; Gabrielsen, Geir W. & Borgå, Katrine (2024). Little seasonal variation of mercury concentrations and biomagnification in an Arctic pelagic food web. Progress in Oceanography. ISSN 0079-6611. 231. doi: 10.1016/j.pocean.2024.103381. Full text in Research Archive Show summary

  Despite numerous studies on mercury in Arctic biota, data from inaccessible, ice-covered regions − especially during the polar night and late winter − remain scarce. This scarcity results in poor understanding of the seasonal dynamics of mercury within the food web. From the Northern Barents Sea, we quantified total mercury and the dietary descriptors δ15N and δ13C as long-term dietary signals (weeks to months) in biota to a) investigate the seasonal pelagic food web structure, b) seasonality in total mercury concentration, c) and its biomagnification in the food web. Mercury and dietary descriptors were analyzed in copepods, macrozooplankton (krill, amphipods, arrow worms and pteropods) and the fishes, Atlantic cod (Gadus morhua), polar cod (Boreogadus saida) and capelin (Mallotus villosus) during spring, late summer, early,and late winter. Seasonal changes were observed in δ15N values in some macrozooplankton and capelin, and some seasonal variation was observed across the food web with depleted δ13C values in spring and enriched δ13C values in late summer. Mercury concentrations were lower (range: 2.49 ng/g dw in the krill Thyssanossa sp. – 70.55 ng/g dw in the pelagic pteropod Clione limacina) than reported from other parts of the Arctic. We found a positive linear relationship between mercury and relative trophic position represented by δ15N, i.e., biomagnification, during all seasons, except in early winter. As Clione limacina likely had different turnover rates for mercury and stable isotopes resulting in low δ15N, but high mercury concentrations in early winter, compared to the other species in the food web, the pteropod was omitted from the regression. By omitting Clione limacina, biomagnification was similar across all seasons (R2adj = 0.45). Thus, we saw clear mercury biomagnification with consistent and little seasonal variation in this high Arctic marine food web despite large seasonal fluctuations in abiotic and biotic conditions.

View all works in NVA

• Giebichenstein, Julia; Warner, Nicholas Alexander; Harju, Mikael; Routti, Heli Anna Irmeli; Varpe, Øystein & Gabrielsen, Geir W. [Show all 7 contributors for this article] (2025). SHORT- AND MEDIUM-CHAIN CHLORINATED PARAFFINS IN AN ARCTIC MARINE FOOD CHAIN. Full text in Research Archive
• Giebichenstein, Julia; Dupont, Nicolas; Harju, Mikael; Varpe, Øystein; Gabrielsen, Geir W. & Andersen, Tom [Show all 7 contributors for this article] (2025). Seasonal Insights into Pollutant Accumulation and Biomagnification in an Arctic Marine Food Web. Full text in Research Archive
• Ziegler, Amanda; Jørgensen, Lis Lindal; Bluhm, Bodil Annikki Ulla Barbro; Giebichenstein, Julia; Borgå, Katrine & Freitas, Thaise Ricardo de (2023). The effect of ice-free summer conditions on benthic food web structure in the Barents Sea. Full text in Research Archive Show summary

  Reduced Arctic sea-ice cover has been shown to alter phytoplankton community composition and reduce the magnitude of vertical flux, thereby reducing the strength of pelagic-benthic coupling. It is predicted that Arctic shelf ecosystems, like the Barents Sea, will transition into sub-polar-like ecosystems under future climatic conditions. However, few studies have provided a benthic perspective to the question of how ice-free conditions in the Arctic will affect food web structure. In this study, we aim to test whether ice-free summer conditions in the Barents Sea and adjacent Nansen Basin alter benthic food web structure and the strength of pelagic benthic coupling. To do so, we used bulk stable isotopes of carbon and nitrogen measured in food sources and benthic consumers, demersal fish, and zooplankton collected during summers with contrasting sea-ice conditions: August 2018 – low sea-ice extent and August 2019 – high sea-ice extent. We compared benthic food web structure across three oceanographically distinct regions from the sea-ice free central Barents Sea shelf and the seasonally ice-free northern Barents Sea shelf to the slope extending into the Nansen Basin. The results of this work will not only improve our understanding of the impact that Arctic sea-ice loss has on benthic communities but provide additional insight to the resiliency of Arctic benthic food webs.

• Borgå, Katrine; McKinney, Melissa A.; Giebichenstein, Julia; Dinh, van Khuong; Gravelle, Amalie Marie Bårnås & Heuschele, Jan David [Show all 10 contributors for this article] (2023). The influence of climate change on accumulation and toxicity of pollutants in Arctic marine food webs. Full text in Research Archive
• Giebichenstein, Julia; Harju, Mikael; Varpe, Øystein; Gabrielsen, Geir Wing; Andersen, Tom & Borgå, Katrine (2023). Across the Seasons: Persistent Organic Pollutants in an Arctic Pelagic Food Web. Full text in Research Archive
• Giebichenstein, Julia; Warner, Nicholas Alexander; Routti, Heli Anna Irmeli; Harju, Mikael; Varpe, Øystein & Andersen, Tom [Show all 8 contributors for this article] (2023). Emerging contaminant accumulation in an Arctic marine food web. Full text in Research Archive
• Borgå, Katrine; McKinney, Melissa A.; Routti, Heli Anna Irmeli; Fernie, Kim J.; Giebichenstein, Julia & Hallanger, Ingeborg G. [Show all 7 contributors for this article] (2022). The influence of global climate change on accumulation and toxicity of persistent organic pollutants and chemicals of emerging concern in Arctic food webs. Full text in Research Archive
• Borgå, Katrine; McKinney, Melissa A.; Routti, Heli Anna Irmeli; Fernie, Kim J.; Giebichenstein, Julia & Hallanger, Ingeborg G. [Show all 7 contributors for this article] (2022). The influence of global climate change on accumulation and toxicity of persistent organic pollutants and chemicals of emerging concern in Arctic food webs. Full text in Research Archive

View all works in NVA