Czech Polar Reports

Blood oxidative stress markers in the 32nd Bulgarian Antarctic expedition participants

Albena Alexandrova, Lubomir Petrov, Georgi Pramatarov, Tanya Sheytanova — Mon, 22 Sep 2025 00:00:00 +0200

Antarctic expeditions are associated with significant stress for participants related to long journeys, work in adverse environmental conditions, and social contact changes resulting in oxidative stress (OS) at the molecular level. This study aimed to evaluate the blood serum OS of the participants in the 32^nd Bulgarian Antarctic Expedition (2023-2024) and related trace elements iron, copper, zinc, and selenium concentrations, lipid profile, and blood parameters. Blood parameters and trace element concentrations were measured in a clinical laboratory. OS indicators were measured spectrophotometrically using kits. The results showed decreased antioxidant enzyme activities and increased glutathione concentration after the expedition in the blood serum from both females and males. No statistical differences in the values of OS parameters between males and females were observed. However, the mean serum total antioxidant capacity after the expedition in males was two times higher than in females. In males, a statistically significant lower erythrocyte sedimentation rate (p<0.05), ferritin (p<0.001), and zinc (p<0.01) levels, catalase (p<0.001) and superoxide dismutase (p<0.05) activities were observed after the expedition. No correlation between enzyme activities and the studied trace element concentrations was found. In conclusion, it can be assumed that the expeditioners’ OS was higher before the expedition, likely because of psychological and physical stress related to overcoming preparation and logistics problems. After the expedition, OS has subsided. In order to maintain good health and increase physical fitness, it could be recommended that polar expeditioners receive dietary supplements, micronutrients, and vitamins in the setting of rational nutrition, especially before an expedition.

Fluctuations of glacier extent in Lake Nam Co and Nyenchen Tanglha Mountains within a decade as detected by machine learning methods of image analysis for monitoring Lhasa terrane, Tibetan Plateau

Polina Lemenkova — Mon, 22 Sep 2025 00:00:00 +0200

Machine learning (ML) methods of satellite image analysis were applied in this study for geological-environmental analysis of glacier extent in Tibetan Plateau, China. The purpose of this work is to map the changes in glacier extent as a hydrological resource and its effects on land cover types using remote sensing data. A quantitative cartographic method of image analysis has been developed using ML algorithms and GRASS GIS scripts. Fluctuations of glacier extent are a key trigger for landscape dynamics in Tibetan Plateau. However, the links between spatio-temporal changes in snow and glacier, and associated land cover changes remain elusive. Six Landsat 8-9 multispectral satellite images covering Lhasa were evaluated. The images show fluctuation in glacier coverage from 2013 to 2023 with a 2-year gap between the observations, characterized by strong heterogeneities caused by climate changes. Glacier dynamics was evaluated for northern range of Nyenchen Tanglha Mountains and Lhasa Terrane, Tibetan Plateau, China. The results present an exploratory analysis of six images (on 2013, 2015, 2017, 2019, 2021 and 2023) for glaciological modelling using ML.

Deuterostichococcus alpinus sp. nov. (Chlorophyta; Trebouxiophyceae) from Antarctica

Shunan Cao, Chunyan Yang, Huimin Tian, Yue Shen, Fang Peng, Qiming Zhou — Mon, 22 Sep 2025 00:00:00 +0200

Lichens are the most dominant components in flora of Antarctica. A lichen epiphyte green alga FACHB-2327, isolated from Antarctic lichen Stereocaulon alpinum, was identified as a new species belonging to the genus Deuterostichococcus. The specimen of lichen Stereocaulon alpinum was collected from King George Island, Antarctica. A comprehensive analysis, including morphology, ultrastructure, habitat, phylogeny and secondary structure of SSU rDNA V9 region, was carried out. The green alga FACHB-2327 was described and named as Deuterostichococcus alpinus sp. nov. to recall the continent where it was discovered. The alga FACHB-2327 forms single celled thalli or pseudofilaments up to three cells; cells are cylindrical with mean size 7-18 (20) × 3-5 µm and rounded ends. It can be distinguished from the other species in genus Deuterostichococcus by morphological characters, including cell size, length/width ratio and phylogenetic position using SSU rDNA and ITS rDNA sequences.

Littoral vegetation of estuarine rivers of the southern part of Vaygach Island and the Yugorsky Peninsula

Mon, 22 Sep 2025 00:00:00 +0200

The saline tidal estuaries of two small rivers of Vaygach Island, the Krasnaya and the Varkulyakha, and one in the area adjacent to the Yugorsky Peninsula, the Nikolskaya River, contribute to the occurrence of salt marshes that are home to halophytic vegetation. In terms of marine exposure, the studied area comprises three types of habitats – low marshes, middle marshes and high marshes, each with a specific composition and structure of the vegetation cover. Along with salt marshes, the study has identified more habitats of smaller area and with specific vegetation, among them lowland wetlands in marsh-tundra ecotones, pebble-sand beaches, rubble beaches, salt lakes, and microdepressions. The marshes of Vaygach Island are classified Vaygachas Arctic type, as evidenced by the presence of halophytic communities dominated by Arctic and hypoarctic species, represented by three associations: Caricetum subspathaceae herbosum, Caricetum glareosae potentillosum egedae and Caricetum glareosae arctantemosum polarae. In our study, the estuarine vegetation has been discovered to comprise a fourth association, Plantaginetum schrenkii. Using the metric scaling method, we provided evidence that the studied estuaries support different vegetation types. While the communities of Vaygach Krasnaya and Varkulyakha estuaries tend to be similar in species composition and structure, the vegetation of the Nikolskaya River estuary appears to be markedly different. The differences relate mostly to the geomorphology of the three estuaries, consisting mainly in the fact that the Vaygach estuarine marshes occupy much larger areas compared to the tidal flats available to halophytic vegetation in the Nikolskaya estuary. The paper proposes a classification of the estuarine vegetation based on ecological and phytocenotic descriptions. Abandoned mines located at the mouth of the Krasnaya River, where polymetallic ores were previously mined, are unlikely to influence the composition and structure of halophytic vegetation. A variety of phytocenoses have formed in this area, as in the mouth of the Varkul'yakha River, where no mining activity has occured.

The ultra-short-term outcomes in performance, aerobic endurance, blood-related parameters, and anthropometrics following prolonged low-intensity ski trekking across Spitsbergen: A case study

Even Jarstad — Wed, 01 Oct 2025 00:00:00 +0200

This study aimed to evaluate changes in endurance capacity, blood-related variables, and anthropometrics following ultra-short-term, prolonged low-intensity ski trekking (LIST). One female (38 years) and one male (52 years) participated in the study in connection with a self-selected ski expedition (hauling ~40-kg sledges each) across Spitsbergen (~126 km), the largest island in Svalbard, Norway. Results revealed that the two moderately aerobically fit participants performed LIST at a mean velocity of ~3.4 km·h^-1, corresponding to ~54–63% of maximal heart rate, ~5 hours·day^-1, for eight days during this unsupported event. The mean daily energy intake during the expedition was ~7.8 MJ· day^-1 (~1 850 kcal·day^-1), of which ~49–61%, ~25–36%, and ~14–15% was derived from carbohydrates, fat, and protein, respectively. Body mass, absolute fat mass, and relative fat mass decreased by 2.2%, 10%, and 8%. In the male participant, time to exhaustion increased by 10% and 3.8% during a ~5 min and ~40 min incremental ski trek-simulated treadmill test. The number of leukocytes declined by 30–41%, as did low-density lipoprotein cholesterol levels. Free triiodothyronine level increased by 19% in the female, whereas thyroid-stimulating hormone concentration increased by 23% in the male. In this category of ski trekkers, one can conclude that ultra-short-term, prolonged LIST can cause slimmer body composition without loss of lean mass, improve performance, reduce low-density lipoprotein cholesterol level, and affect metabolic hormones associated with the pituitary-thyroid axis. However, such an event may impair the immune system.

Occurrence and flux of polycyclic aromatic hydrocarbons in settling particulate matter from the water column in Fildes Bay, Antarctica

Mon, 22 Sep 2025 00:00:00 +0200

This study investigates the occurrence, sources and fluxes of polycyclic aromatic hydrocarbons (PAHs) in settling particulate matter (SPM) from the water column from two locations in Fildes Bay (King George Island), Antarctica. Fildes Bay is an area influenced by research stations, maritime activities, and tourism. The SPM sample was obtained from a Sediment trap (20–50 m depth) during summer Antarctic expeditions. In this work, which complements our previous study regarding of PAHs (18), PAHs were quantified by gas chromatography–mass spectrometry (GC–MS). The results show Σ18PAHs ranged from 2 to 18 ng g^-1dry weight (DW), in which PAHs predominate 2- to 3- ring. The fluxes from SPM in the water column ranged from 0.03 to 0.70 ng m^-2day^-1and increased near Collins Glacier. The temporal variability observed during the sampling period highlights the influence of both natural and anthropogenic factors. These findings contribute to the scarce dataset available for Antarctic marine environments and emphasize the importance of long-term monitoring to assess pollutant dynamics under changing climatic conditions.

Scene-to-Scene classification variability in spatiotemporal glacier surface facies mapping in Svalbard

Mon, 22 Sep 2025 00:00:00 +0200

Spatiotemporal analysis of glaciological phenomena provides a robust assessment of a glacier’s health. Glacier surface facies (GSF) are direct indicators of the state of snow and ice within a glacier. However, long-term analyses of GSF via optical satellite products presents challenges stemming from data availability, weather conditions, and variations in mapping methodologies. In this study we present the first decadal analysis of GSF in Svalbard using optical satellite data. Utilizing unsupervised classification on images of the Vestre Broggerbreen glacier from 2013 to 2023, we identify and quantify the variations between facies observed on the images and their classified spatial distributions. The identified facies comprise of snow, firn, glacier ice, and dirty ice, with a fifth thematic class of shadowed snow. In certain imagery, snow and firn are labelled as ‘snow 1’ and ‘snow 2’ due to the derived reflectance and appearance of firn differing from established patterns in the literature, while remaining spectrally distinct from snow. Our analysis suggests that shadowed snow induces the most misclassification in overall assessment of GSF. Shadowed snow and dirty ice produce convoluted spectral reflectance that in combination with the overall darkening of the glacier severely misrepresented firn, underreported dirty ice, and produced inaccurate maps. Spatially, dirty ice was classified with a lower distribution in 2023 (0.49 km²) than in 2013 (0.58 km²). Moreover, firn/snow 2 was classified as a larger area in 2023 (1.01 km²). These results indicate a pressing need to identify long-term trends affected by scene-to-scene distortions. Our future experiments involve multi-decadal supervised analyses of GSF in the high Arctic involving image-specific discussions, thereby providing crucial information for refinement of supraglacial monitoring with multispectral data.

Developing explainable AI models for predicting snowpack variability in Polar regions

Sidra Sidra, Shah Mehmood Wagan — Mon, 22 Sep 2025 00:00:00 +0200

Accurate prediction of variability of polar snowpack is central to understanding global climate change and its impacts on ecosystems, sea-level rise, and weather patterns. Traditional, physically based snowpack models commonly fail to capture full range of complexity that realistic snow dynamics can display, especially under extreme climate events. On the contrary, machine learning (ML) models can enhance predictive accuracy but lack interpretability and thus are challenging to apply in scientific contexts. This research proposes construction of explainable AI models for prediction of polar snow-pack, emphasizing how to interpret domain knowledge coupled with state-of-the-art techniques in AI. Physics-informed neural networks are used herein to embed physical laws, Graph Neural Networks (GNNs) to represent spatial dependencies, and Recurent Neural Network (RNNs) for temporal sequences. Several post-hoc explanation techniques, such as SHAP and saliency maps, together with the development of causal inference models, are applied in such a way that the transparency and scientific basis of the models are preserved.

Lichens in the vicinity of Colesdalen, one of the “hot spots” of the Svalbard archipelago

Liudmila A. Konoreva, Sergey V. Chesnokov — Mon, 22 Sep 2025 00:00:00 +0200

This study summarizes the lichen diversity in the Colesdalen area of Svalbard, where a total of 234 species are known. Notably, 112 of these lichen species are reported for the first time in this region. Among them, the newly recorded species are Arthonia granitophila, Ionaspis obtecta, Micarea denigrata, Poeltinula interjecta, Rhizocarpon infernulum, R. subgeminatum, Rinodina mniaroea var. cinnamomea, Sagedia zonata, Sarcogyne lapponica, which are new to Svalbard. Furthermore, Arthonia granitophila and Poeltinula interjecta are documented for the first time in the Arctic. Additionally, 27 species have been identified as new to Nordenskiöld Land (Central Spitsbergen). The ecological conditions of the Colesdalen area, including its unique microhabitats and sub-strate availability, significantly influence the lichen biodiversity and site-dependent vege-tation composition. This research contributes to the knowledge of local biodiversity of lichens and highlights how certain species can thrive beyond their typical ranges due to specific environmental factors – substrate, altitude, anthropogenic impact, distance from glaciers, humidity. Approximately half of the identified species are known only from the study area or from a few locations on Svalbard. This highlights the specificity of the natural conditions of the study area as well as the complex interactions between natural ecosystems and human-modified environments, emphasizing the importance of further study and documentation of Arctic lichens.

Desiccation resistence of photosynthetic processes in photosystem II of Antarctic moss Sanionia uncinata assessed by two chlorophyll fluorescence methods

Mon, 22 Sep 2025 00:00:00 +0200

Dehydration-induced decrease of photosynthetic performance in mosses is a general response to thallus dessication. The decrease is caused by changes in photosystem II (PSII) functioning which is sensitively reflected in several chlorophyll fluorescence (ChlF) parameters. Apart from the decrease in potential yield of photosynthetic reactions in PSII (F_V/F_M), several protective mechanisms are activated during moss desiccation, non-photochemical quenching (NPQ) in particular. This is study focused on NPQ changes during the desiccation of Antarctic moss Sanionia uncinata. NPQ induction and relaxation curves were recorded during gradual dehydration from a fully wet state (relative water content [RWC] = 100%) to a fully dry state (RWC = 0%). Three key NPQ parameters were evaluated: NPQ_max (maximum value), NPQ_termin (at the end of induction) and NPQ_relax (end of dark relaxation). The initial slope (a) and dark relaxation (b) of NPQ were analysed. Additionally, fast chlorophyll fluorescence transients (OJIPs) were measured and the parameters related to PSII functioning evaluated for decreasing RWC. The relationships between the ChlF parameters and RWC were investigated. Results indicated that NPQ induction and relaxation curves – along with the OJIP-derived parameters were sensitive to dehydration. Since critical RWC for all the investigated ChlF parameters were found below 20%, Sanionia uncinata might be ranked into drought-resistant moss species.