Polar Research

Small catchments: remote sensing approach for environmental research in the High Arctic

Aleksandra Wołoszyn, Iwo Wieczorek, Marek Kasprzak — Thu, 09 Jul 2026 11:56:44 +0000

This study examines the morphometric characteristics and environmental changes in 143 small catchments within Wedel Jarlsberg Land, southern Svalbard, focusing on the influence of topography on glacier retreat, lake evolution, and vegetation dynamics. The catchments analysed varied in size, with 65% smaller than 4 km². Elevation ranged from 1.9 to 1200 m a.s.l., and the catchments exhibited significant topographic variability, including steep slopes and varying exposures. Glaciers in the study area have undergone a 30% reduction in area from 1936 (228.34 km²) to 2020 (158.26 km²). This retreat has led to the expansion of glacial lakes, particularly within moraines, with a general trend towards increasing numbers and sizes of lakes over time. Vegetation changes were assessed using normalized difference vegetation index data from 1979 to 2020, revealing few increasing trends. Topographical features, including mean elevation, slope and catchment size, were analysed to understand their impact on glacial retreat and vegetation growth. The study found that mean slope and aspect had the strongest influence on vegetation dynamics, and that mean elevation and slope values have an impact on glacial retreat in the High Arctic.

A thermophilic hormone-sensitive lipase family esterase Est1404 identified from an Antarctic bacterium Pseudomonas sp. E2-15

Mon, 27 Apr 2026 00:00:00 +0000

Esterases are a group of enzymes with a diverse range of uses in industry. We identified a novel hormone-sensitive lipase (HSL) in the esterase family, Est1404, through cloning and expression from the Antarctic bacterium Pseudomonas sp. E2–15, from soil collected on King George Island. Investigations showed that the Est1404 enzyme is a thermophilic esterase that maintains 90–100% activity throughout the temperature range of 60–90 °C. It exhibits the highest catalytic activity towards p-nitrophenol butyrate at 70 °C and pH 8.5. Est1404 was inhibited by the serine-modifying reagent phenylmethylsulfonyl fluoride, but thiol reagents such as dithiolthreitol stimulated its activity. Metal chelating chemicals, such as ethylenediaminetetraacetic acid, did not affect its activity. Phylogenetic analysis indicated that Est1404 is in the GDSAG subfamily of HSL. The enzyme contains a GDSAG motif with an active serine (S) positioned within a catalytic triad consisting of highly conserved Ser¹⁵⁶, Asp²⁵⁰ and His²⁸⁰ residues. The thermal stability of the Est1404 esterase makes it potentially useful in industrial catalysis.

Weathering above the tides: how iceberg-roll-generated waves shape Arctic rocky shores

Mon, 13 Apr 2026 00:00:00 +0000

A significant limitation of the current understanding of cold coast evolution is the paucity of field observations on the development of rocky coasts in glaciated parts of the Arctic. To address this gap, we present a pilot study that utilizes a Schmidt hammer to investigate variations in rock surface resistance across four distinct horizontal zones along the rocky bay of Zion Church, Ilulissat, near one of the prevailing routes of iceberg transport in western Greenland. The primary finding of the study is a substantial decrease in rock resistance within the area above the high-tide level. We relate this result mainly to waves generated by iceberg-roll events in conjunction with chemical and biological weathering. This case study seeks to elevate the status of iceberg-roll-generated waves from a mere curiosity to a substantial geomorphic agent that shapes the microrelief of Arctic coastlines.

Documenting an isolated and high-priority Arctic cultural heritage site: case study from Kapp Pettersen, Svenskøya, Svalbard

Iwo Wieczorek, Ionut Cristi Nicu, Zuzanna M. Swirad, Mateusz Strzelecki — Tue, 10 Mar 2026 05:10:31 +0000

With a warming climate, changing weather patterns and increased erosion from various permafrost- and marine-related processes, the cultural heritage (CH) sites in Svalbard are increasingly vulnerable to destruction. Documentation of CH sites in the Arctic can be very difficult on account of the harsh environment, remoteness (and associated costs), limited access time windows and—in Svalbard—the need to obtain permits from local authorities. The main objectives of this study are: (1) to document an isolated and prioritized CH site in Svalbard—the hut at Kapp Pettersen, Svenskøya—using an uncrewed aerial vehicle and ground photography; (2) to identify the effects of coastal erosion and permafrost-related processes on the cabin; and (3) to gain a better understanding of the landscape surrounding the site. We found that the shoreline had retreated, on average, by 0.42 m/yr between 2010 and 2024. This is significantly more than has been documented at other CH sites in Svalbard. The limited number of photographs of the hut meant that a three-dimensional representation could not be made. However, a detailed auditory description of the hut was made during the visit. This study highlights the challenges and limitations of Arctic CH documentation.

Comparative metagenomics of two shallow marine microbial communities in western Greenland

Daniel G. Dick — Mon, 13 Apr 2026 00:00:00 +0000

Metagenomic profiles of marine microbial communities from Greenlandic coastal waters remain scarce, despite the central role played by this region in discussions of global climate change. This study characterizes the taxonomic and functional structure of two near-shore shallow marine fjord mouth microbial communities from sites in western Greenland that differ in sea-surface temperatures, mean annual ice-coverage levels and annual glacial meltwater flux rates. Results indicate limited taxonomic and functional overlap between these two locations, with significant differences in the normalized abundance of 3372 species (25% of observed taxa) and 620 functional genes (49% of functional genes observed). At Sisimiut, a typical open-water “Baffin Bay” site characterized by moderate sea-surface temperatures, minimal annual sea-ice cover and limited glacial input, the metagenome is dominated by diverse chemolithotrophic taxa, including sulphate-reducing, nitrogen-fixing and methanogenic lineages. At the Ilulissat Icefjord, where low sea-surface temperatures, high turbidity, low salinity and strong glacial influences prevail, the community is less diverse and is dominated by psychrophilic (cold-adapted) bacteria such as Colwellia hornerae PAMC 20917. Functional profiles further distinguish these sites: the Ilulissat metagenome is enriched in genes common to ice-associated and cold-adapted metabolisms (e.g., exopolysaccharide biosynthesis, dimethyl-sulphide and dimethylsulfoniopropionate cycling), whereas these genes are comparatively rare at Sisimiut. Together, these data sets provide a descriptive baseline for these two sites and a framework for future comparative studies in the region.

Polar bear predation on barrier island bird colonies in Arctic Alaska increases with sea-ice decline

Kayla Shively, George Divoky, Anneke Van der Laan, Martin Robards — Thu, 25 Jun 2026 11:09:02 +0000

Anthropogenic carbon emissions are warming the Arctic, disrupting ecosystems, and changing the behaviour and interactions of their component species. As summer sea ice diminishes, polar bears (Ursus maritimus) are losing access to traditional seal prey and are increasingly forced onto land, where bears can consume eggs, nestlings and sometimes adults of coastal-nesting marine birds. This behaviour has been poorly documented in northern Alaska. We present observations of polar bears in the Alaskan Beaufort Sea preying on Mandt’s black guillemot (Cepphus grylle mandtii) and Pacific common eider (Somateria mollissima v-nigrum). At Cooper Island, predation on guillemots was episodic (27% of years) and negligible from 1975 to 2007, but increased during 2008–2010, when bears caused 43% nestling mortality. Bear-resistant nest cases deployed in 2011 initially reduced losses until 2024 and 2025, when bear predation led to complete reproductive failure. In 2024, at a common eider colony on Spy Island, a single polar bear destroyed 89% of nests in less than a day. Despite extensive surveys of common eider colonies between the 1970s and early 2000s, reports of polar bear predation at these colonies were isolated and rare. These observations reveal a rapid shift in predation pressure, adding to existing climate-related impacts on these birds, including less prey and flooded or eroded nesting habitat. Our observations demonstrate how sea-ice loss is transforming Arctic ecosystems, creating unsustainable pressures on vulnerable bird populations and underscoring the urgency for solutions that will need to address the root causes of climate warming.

Bowhead whales (Balaena mysticetus) are copycats, imitating sounds heard in their environment

Samuel M. Llobet, Heidi Ahonen, Christian Lydersen, Kit M. Kovacs — Fri, 10 Apr 2026 15:29:09 +0000

In this study, we provide evidence that bowhead whales (Balaena mysticetus) imitate bearded seal (Erignathus barbatus) calls, integrating them into their own elaborate songs, demonstrating this cetacean species’ capacity for complex vocal learning. Bowhead whales also appear to imitate additional species—narwhal (Monodon monoceros)—and even environmental noise (ice sounds) in the Svalbard area. This behaviour likely reflects evolutionary pressure related to song diversity, mating success and ecological adaptation.

An Adélie penguin (Pygoscelis adeliae) 200 km from the sea

Sebastien Descamps, Anca Cristea, Geir Ove Aspnes — Tue, 07 Apr 2026 00:00:00 +0000

This brief note reports an observation of an Adélie penguin (Pygoscelis adeliae) 200 km from the open sea, at Troll Research Station, in Dronning Maud Land, Antarctica, on the morning of 5 January 2026. The bird, which appeared to be in good condition, was not interfered with and was last seen walking away from the station in the afternoon. This observation and previous reports of penguin signs so far inland are rare and raise questions about how these birds navigate.

Actor participation in the Arctic Council, 1998–2025: a new data set

Anna Ivanova — Thu, 16 Apr 2026 06:19:47 +0000

The Arctic Council, once the primary forum for Arctic governance, has been facing significant disruptions since 2022, raising questions about the future direction of regional cooperation. Stored at the Arctic Data Center in the US, the ArcticPart data set covers over 25 years of participation in 171 meetings of the Arctic Council, including Ministerial, Senior Arctic Officials and selected working, expert and task force groups. It offers the most complete and systematically organized record of actor participation from 1998 to 2025. This data set provides opportunities to analyse the evolution of Arctic governance, including changes in member state participation after 2022, the shift of meetings to the working group level, the changing role of observers and non-state actors in maintaining cooperation and the effects of chairship rotation.