Glacier mice as a temporary sink for fallout radionuclides and heavy metals on the Norwegian glacier Austerdalsbreen.

Glacier mice are peculiar rolling or stationary moss balls found on the surface of some glaciers. They may harbour an ecological habitat for cold-adapted invertebrates and microorganisms, but little is known about their potential to accumulate and disseminate harmful elements and substances. In this study, we investigate the presence of fallout radionuclides (137Cs, 238Pu, 239Pu, 240Pu, 210Pb) and heavy metals (Pb, As, Hg, Cd) in glacier mice and compare the results to bryophytes from adjacent glacier ecosystems. Samples were collected at Austerdalsbreen, a Norwegian outlet glacier from Jostedalsbreen ice cap. Maximum activity concentrations for bryophytes are 552 ± 12 Bq kg-1 for 137Cs, 3485 ± 138 Bq kg-1 for 210Pb, 0.0223 ± 0.065 Bq kg-1 for 238Pu and 4.34 ± 0.43 Bq kg-1 for 239+240Pu while maximum heavy metals concentrations are 70.5 mg kg-1 for Pb, 1.0 mg kg-1 for As, 1.6 mg kg-1 for Hg and 0.13 mg kg-1 for Cd. Maximum activity concentrations in cryconite are 1973.4 ± 5.0 Bq kg-1 for 137Cs, 3632 ± 593 Bq kg-1 for 210Pb, 0.51 ± 0.11 Bq kg-1 for 238Pu and 13.1 ± 1.4 Bq kg-1 for 239+240Pu and maximum heavy metal concentrations are 50.4 mg kg-1 for Pb, 3.4 mg kg-1 for As, 1.5 mg kg-1 for Hg and 0.082 mg kg-1 for Cd. We find that glacier mice show lower activity concentrations of radionuclides compared to cryoconite. The major source of plutonium isotopes is related to global fallout, whereas detected radio-cesium may be additionally affected by post-Chernobyl fallout to an unknown extent. Comparison between glacier surface and adjacent glacial habitats shows higher concentrations of heavy metals in glacier mice on the glacier ice surface and medial moraines compared to bryophytes in the glacier forefield. Glacier mice exported from a receding glacier may affect the cycling of radioactive and metal pollutants in developing proglacial ecosystems.

Exploring avian exposure to parent polycyclic aromatic hydrocarbons (PAHs): Using the common eider Somateria mollissima in a global context.

Compared to other organic contaminants, birds are rarely studied for their exposure to polycyclic aromatic hydrocarbons (PAHs), mainly due to their effective metabolization of parent PAHs. However, as some studies suggest, exposure to PAHs may result in adverse health effects including decreased survival, especially following oil spills. In the present study, we analyzed samples from a sea duck, the common eider Somateria mollissima including feathers, preen oil, blood, liver and bile, to evaluate whether non- lethally collected samples could be reliably used for avian biomonitoring strategies. Phenanthrene was the only individual PAH detected across sample types, with the highest concentration found in preen gland and the lowest in blood. Significant differences in concentrations were observed between bile vs preen gland and liver vs preen gland, while for most compounds neither blood nor feathers showed detectable levels of parent PAHs. Therefore, the utility of those sample types for PAH exposure assessment may be limited and should be interpreted with caution, moreover as several physiological factors may affect them. Additionally, we also provide a comparison with the available literature to review current avian PAH exposure assessment and outline future research focused needs.

Chemical element distribution in Arctic soils: Assessing vertical, spatial, animal and anthropogenic influences in Elsa and Ebba Valleys, Spitsbergen, Svalbard.

The Arctic region is threatened by climate change and pollution caused by human activities which potentially influence the elemental concentrations available to and from the biota. To better understand this delicate balance, it is crucial to investigate the role of several factors. Therefore, we quantified the level of 43 chemical elements in soils from Elsa and Ebba Valleys, Petunia Bay, Spitsbergen, a region that has experienced lasting environmental impacts from historical mining activities. We evaluated the a) vertical sampling influence by examining the variation in element distribution between the soil upper and deeper layers, b) animal influence by verifying the role of native animals, particularly vertebrates, in introducing thought faeces elements to the soil and c) anthropogenic influence by studying the spatial geographical differences in element distribution based on the degree of human pressure between the valleys. Our analysis also includes data on soil organic matter (SOM) and mineral composition. Both valleys exhibited similar mineralogical composition, but Elsa Valley had higher concentrations of most analyzed elements compared to Ebba Valley. Despite the contribution of vertebrate feaces, no increase in element concentrations was observed in the animal-influenced soils. The sampled soil layers had similar chemical element profiles for most elements. SOM content tended to be higher in superficial soils and showed a strong positive correlation with most quantified elements. The higher concentrations in Elsa Valley reflect its past mining and mineral exploration, making this area more significantly impacted than Ebba Valley. Surprisingly, vertebrate animals do not appear to influence the concentrations of chemical elements or organic matter in soils. Our findings provide valuable insights into the legacy of past mining activities and mechanisms driving environmental change in the Arctic.

Cryoconite - From minerals and organic matter to bioengineered sediments on glacier's surfaces.

Cryoconite is a mixture of mineral and organic material covering glacial ice, playing important roles in biogeochemical cycles and lowering the albedo of a glacier surface. Understanding the differences in structure of cryoconite across the globe can be important in recognizing past and future changes in supraglacial environments and ice-organisms-minerals interactions. Despite the worldwide distribution and over a century of studies, the basic characteristics of cryoconite, including its forms and geochemistry, remain poorly studied. The major purpose of our study is the presentation and description of morphological diversity, chemical and photoautotrophs composition, and organic matter content of cryoconite sampled from 33 polar and mountain glaciers around the globe. Observations revealed that cryoconite is represented by various morphologies including loose and granular forms. Granular cryoconite includes smooth, rounded, or irregularly shaped forms; with some having their surfaces covered by cyanobacteria filaments. The occurrence of granules increased with the organic matter content in cryoconite. Moreover, a major driver of cryoconite colouring was the concentration of organic matter and its interplay with minerals. The structure of cyanobacteria and algae communities in cryoconite differs between glaciers, but representatives of cyanobacteria families Pseudanabaenaceae and Phormidiaceae, and algae families Mesotaeniaceae and Ulotrichaceae were the most common. The most of detected cyanobacterial taxa are known to produce polymeric substances (EPS) that may cement granules. Organic matter content in cryoconite varied between glaciers, ranging from 1% to 38%. The geochemistry of all the investigated samples reflected local sediment sources, except of highly concentrated Pb and Hg in cryoconite collected from European glaciers near industrialized regions, corroborating cryoconite as element-specific collector and potential environmental indicator of anthropogenic activity. Our work supports a notion that cryoconite may be more than just simple sediment and instead exhibits complex structure with relevance for biodiversity and the functioning of glacial ecosystems.