Quantifying floridean starch storage patterns in Arctic rhodoliths: blue carbon implications

Rhodoliths composed of crustose coralline algae (CCA) are marine calcifiers of global significance. Here, we investigate how floridean starch storage patterns of Arctic rhodoliths from Svalbard are affected by environmental conditions. Quantifying the amount of starch in photomosaic scans of rhodolith slabs via amylopectin–iodine complex formation, we found that shallow water rhodoliths contain significantly higher starch percentages compared to the deeper-water dwellers. We conclude that the observed starch patterns are mainly controlled by water depth because light and rhodolith turnover frequency both decrease in deeper waters. Regarding rhodolith turnover, the occasional burial of turned rhodoliths in deeper waters can result in a dieback of the outer CCA thallus areas, which contain important starch supplies. As rhodoliths are both calcifiers and photoautotrophs, we highlight their relevance in potentially contributing to global blue carbon, that is, their role as a marine carbon sink. In this context, our quantification approach of floridean starch patterns in rhodoliths provides a straightforward basis for further studies on this topic

Relative importance of nanoflagellate grazing and viral lysis for the mortality of heterotrophic bacteria and Synechococcus spp. in a high-latitude fjord (Adventfjorden, Svalbard) during the summer

Viral lysis and grazing play crucial but distinct roles in microbial community dynamics and carbon cycling. Yet, their relative influence on the abundance of heterotrophic bacterial and picophytoplankton populations, especially in Arctic fjords, remains poorly understood. To address this knowledge gap, we conducted modified dilution experiments in Adventfjorden, Svalbard, to quantify microbial growth, grazing pressure and virus-induced mortality. Our results showed that the abundance of virus-like particles (VLP) ranged between 1.4 and 8.9 × 106 viruses ml−1, with a negative correlation to salinity. This suggests that freshwater inputs, such as meltwater, could contribute to higher VLP abundance in these waters. The VLP-to-bacteria ratio varied between 9.8 and 700.9, with a large variation below a salinity of 28 PSU and an inverse correlation with salinity. Grazing, primarily by nanoflagellates, emerged as the dominant factor in reducing heterotrophic bacterial and Synechococcus spp. populations, accounting for 12–55% and 20–110% of their production losses, respectively. This study was conducted in summer, when meltwater discharges entered coastal waters in Svalbard fjords at an extremely high rate, providing an opportunity to study microbial processes under projected future warming conditions

Arctic shipping 2013–2022: the traffic has grown, with big variation between regions, seasons and ship types

This article analyses decadal changes in Arctic ship traffic from 2013 to 2022, using data from the Arctic Ship Traffic Data system (ASTD). Shipping in waters affected by sea ice has grown, but how much depends on geographical definitions. The Polar Code area had an average annual growth of 8.7%, mainly due to more traffic in the Barents Sea, where most Arctic ship traffic occurs. Where analysts set the southern boundary of the Barents Sea significantly influences the statistics, for example, to what extent fishing vessels dominate Arctic shipping. Reports on Arctic shipping should consider the significant intra-Arctic variations in activity levels, growth rates and traffic composition. The Kara Sea experienced the biggest annual growth rate—14% on average—because of petroleum projects that have introduced big oil and gas tankers. In contrast, there is minimal activity and growth in the Large Marine Ecosystems of the Northern Canadian Archipelago and the Central Arctic Ocean. Even though the winter traffic has grown in the Barents Sea, the Kara Sea and Baffin Bay, the activities there remain distinctly seasonal. In other seas, ships almost vanish in winter. Transit shipping over the Arctic is still insignificant in a global context. The standard reports in the ASTD are important for understanding Arctic shipping and should be improved. In particular, the Polar Code area needs to be subdivided to enable consistent reporting on overall pan-Arctic and intra-Arctic developments. Definitions for transit traffic should also be agreed upon and opportunities for automatic reporting accordingly investigated

Mesoscale atmospheric processes over an Arctic fjord as observed during a research aircraft campaign in winter

Unique research aircraft observations were conducted within an Arctic fjord in Svalbard during three days in March 2013. Wijdefjorden is 110 km long, 5–15 km wide and has a north–south axis. Two-thirds of the fjord were covered by land-fast sea ice, but the northern part of the fjord was open. On two days the flow over the fjord was largely controlled by orographic channelling of the north-easterly wind, and on all three days a cold-air mass accumulated over the sea ice in the fjord and gradually propagated towards the open sea in the north. An ice breeze (analogous to land breeze) circulation, due to a strong temperature gradient across the sea-ice edge, was a key driver of the southerly near-surface wind over the fjord. On two days, the cold-air mass reached the open sea and the near-surface air mass warmed rapidly by several Kelvins. On one day, the channelled northerly flow pushed the cold-air mass to the south, from where it gradually propagated back to the north after the channelled flow had weakened. The results suggest that the channelling of the large-scale flow in the fjord can suppress the ice breeze to a shallow near-surface layer and even push the cold-air mass far south of ice edge. The near-surface air temperature and wind fields that were based on the Copernicus Climate Change Service Arctic Regional Reanalysis (CARRA) data set included large errors because CARRA did not have any sea ice in the fjord

Larsen’s cairn: the birth of a new historical site in Antarctica

This article describes the history of Larsen’s cairn, one of the oldest historical sites in Antarctica, and explains how it became one of the most recently declared Historical Site and Monuments (HSMs) on the continent. Norwegian explorer and whaler Carl Anton Larsen constructed the cairn on Marambio/Seymour Island during the Norwegian Whaling Expedition in 1892. Officially designated as C.A. Larsen Multiexpedition Cairn (HSM 94), this site featured in several episodes of Antarctic history, spanning three periods of Antarctic history: Antarctic whaling, the Heroic Age of Antarctic exploration, and a period characterized by the installation of permanent stations at the end of World War II. Argentina, Norway, Sweden and the UK have all had some involvement in the cairn and all four nations now share an administrative role vis-à-vis the HSM, making it the HSM with the largest number of administrators to date. Adding to its significance, the cairn is linked to the earliest phase of invertebrate palaeontology in Antarctica and can also be considered the first material remains of the Norwegian presence in Antarctica

DNA metabarcoding of non-fungal eukaryotic diversity in air and snow of Livingston Island, South Shetland Islands, Antarctica

A major natural route of dispersal to Antarctica is often assumed to be atmospheric transport, although few studies have documented this in detail. Aerial dispersal to Antarctica is very challenging as the continent is geographically remote from other land areas and is isolated by the atmospheric circumpolar vortex. Detailed information about aerial routes by which microorganisms arrive and circulate in Antarctica is generally lacking, as few aerobiological studies have focused on eukaryotes and those that have predominantly relied on traditional morphological identification. Recent advances in molecular biology, such as DNA metabarcoding by high throughput sequencing (HTS), have provided a powerful new tool for the study of atmospheric biological diversity and can retrieve levels of diversity an order of magnitude higher than traditional methods. In this study, we used HTS to investigate the diversity of non-fungal eukaryotes present in the atmosphere and freshly precipitated snow on Livingston Island. In a total of 740 m3 of air and 3.76 L of snow sampled, representatives of four kingdoms (Protozoa, Chromista, Viridiplantae and Animalia) and five phyla (Ciliophora, Ochrophyta, Chlorophyta, Magnoliophyta and Porifera) were found. The most diverse phylum was Chlorophyta, represented in our samples by 10 taxa, with Trebouxia asymmetrica Friedl & Gärtner the most abundant representative

When does fakery in nature documentaries go too far and what about the scientists in them?

This editorial reflects on deception in nature documentaries, ranging from trifling and, arguably, justifiable tricks to the outright hoaxes that gravely mislead viewers and damage public trust in science. Examples are drawn from Disney, BBC, Discovery Channel, Animal Planet and other productions. Scientists who are asked to appear in nature documentaries are advised to proceed with caution and to safeguard their right to speak publicly about falsehoods and dupery in such productions. The availability of inexpensive video-fabricating applications raises the spectre of additional problems

The muskox (Ovibos moschatus) in Sweden: update on a small wild population with an uncertain fate

Once widespread across the Holarctic region, the iconic and pre-historic muskox (Ovibos moschatus) has seen a significant range reduction, with endemic populations now restricted to North America and scattered populations introduced throughout Eurasia. In 1971, five individuals from the introduced Norwegian population migrated across the border into Sweden and re-established a natural Swedish muskox population in Härjedalen. While the size of this population has since fluctuated, up-to-date knowledge on the population size and status has been missing. In the summer of 2024, we therefore conducted a population survey and estimated the current population size to eight individuals. Although the population remains small and despite the absence of a formal wildlife management plan, the presence of a sub-adult and calf still shows an ongoing reproduction and suggests a viability and long-term local continuity of muskoxen in the area. Compared to the well-studied populations in North America and Greenland, little is known about the foraging ecology, habitat selection and ecological role of muskoxen in Scandinavia. Synthesizing published research from other regions, we explore the potential ecological services of the Swedish muskoxen, such as mitigating climate-induced changes like shrubification. We also report the results of our count of the population—eight individuals, including a calf and a sub-adult—and discuss its future prospects in Sweden, arguing that the environmental conditions in Scandinavia are indeed capable of supporting muskox populations

The history of the musk ox farm in Bardu, Arctic Norway

In 1969, a musk ox (Ovibos moschatus) farm was started in Bardu, northern Norway, with 25 calves captured in Greenland. John J. Teal Jr., a professor at the University of Alaska, was the primus motor of the initiative, which had the aims of domesticating the musk oxen, distributing the domesticated animals to local farms, exhibiting the animals commercially and providing local knitters with the valuable underwool (qiviut) and, thereby, an income-generating activity. Teal withdrew from the project in 1973. The farm operated until 1975, when a bull, one of three escapees, killed a local hunter. Little has been published in English about the Bardu farm, which was one of only six large-scale musk ox farms ever established, and the only one outside North America. This Perspective piece describes the emergence of the idea of domesticating musk oxen in early 20th century North America; capturing the founding stock; constructing and operating the farm; the effort to produce qiviut handknits; and the circumstances leading to the farm’s closure. I conclude that the Bardu farm achieved none of its animal husbandry or socio-economic goals. The farm’s failure can be attributed to a chronic lack of money; the absence of a clear description of its purposes and a plan to achieve them; the failure to tame the musk oxen and to contain the rutting bulls; and other causes. On a positive note, the University of Tromsø’s research on the surviving animals after the farm closed yielded data relevant to free-living and farm-raised musk oxen

A 90-year record of glacier changes in the Novaya Zemlya Archipelago, Russian High Arctic

Glacial retreat in the Russian High Arctic, particularly in the Novaya Zemlya Archipelago (NZA), is emblematic of global warming. Some global models project that, by 2100, sea-level rise contributions from melting glaciers in this region could be comparable to contributions from Antarctica’s and Greenland’s peripheral glaciers. However, historical glacier change in the NZA remains poorly known. Here, we present the longest decadal chronology of glacier change in the NZA to date, including a 90-year record (ca. 1931–2021) of frontal length change, and a 70-year record (1952–2021) of glacier area change. Using a combination of survey records, historical maps and satellite imagery, we analyse changes for 63 outlet glaciers, representing 86% of the NZA’s total ice mass. Our results show that the average frontal retreat rate increased each decade since the early 1970s, reaching a peak retreat rate of 65 m a-1 between 2011 and 2021. Glaciers terminating in the Barents Sea experienced the greatest losses, retreating an average of 4.2 km (11.6%) since 1952. During this time, the total glacier area decreased by 1606 km2 (10%). We identified increasing summer air and sea-surface temperatures as key drivers of accelerated glacier retreat, with peak air and sea-surface temperatures occurring from 2011 to 2021, corresponding to the period with the fastest retreat rates and the largest glacier area loss