Navaga, Eleginus nawaga, are an important component of some Arctic shelf seas, primarily in the Russian Arctic, yet very few publications on Navaga are available in the western scientific literature. Based on literary sources, a description of the distribution and biology of Navaga, Eleginus nawaga, in the White Sea, as well as a history of their fishery, are provided. Long-term changes in biological

Tardigrades are potentially dispersed by birds, but the extent of the interactions between birds and tardigrades is virtually unknown. We discovered nine tardigrades within feces of White-bellied Seedsnipe (Attagis malouinus) collected from high Andean tundra on Navarino Island, Chile. Eight of the tardigrade specimens began moving once rehydrated. Two specimens belonged to the genus Adropion (Hypsibiidae)

Ground-nesting birds, such as large gulls and skuas, are known to include a variety of items in their nests as pseudo-eggs, as well as to adopt the eggs of conspecifics or other species. Three hypotheses have been proposed to explain this phenomenon: incubation stimulus, mistaken food, and mistaken egg hypotheses. Of 657 Brown Skua Stercorarius antarcticus nests surveyed on Marion Island during the

This is an integrative study of a potential zoonotic digenean from the Magellanic Southwestern Atlantic coast. The life cycle of the gymnophallid Gymnophalloides nacellae Cremonte, Pina, Gilardoni, Rodrigues, Chai and Ituarte, 2013 (Digenea) at the type locality, Puerto Deseado (47° 45′ S, 65° 51′ W), Santa Cruz province, was elucidated. This digenean uses the upper subtidal clam Gaimardia trapesina

The continued decline in the small breeding population of southern elephant seals Mirounga leonina at Gough Island (40°19′S, 9°57′W) over a period of 46 years (1973–2019) signals the likely extirpation of the species at the northernmost extent of its breeding range in the Southern Ocean. The estimated number of births declined from a high (n = 38) in 1975 to a low (n = 2) in 2019, a 95% reduction at

Polar cod, Boreogadus saida, is an important part of Arctic and boreal marine ecosystems. Knowledge of polar cod population genetic structuring can provide insight into how the species may respond to environmental change, and allow for establishment of meaningful management units. To examine population genetic structure of B. saida, we analysed nine microsatellite DNA loci in 2269 fish collected at

Oxidative stress is considered the main physiological mechanism involved in short- and long-term life histories, operating through the progressive deterioration of tissues, with consequences in the reproductive performance, growth patterns, aging, and survival. Besides, the Antarctic Peninsula environmental change, registered in the last decades, makes essential the antioxidant status knowledge of

As in many Arctic regions, the fauna and biodiversity of Polar Ural lakes are not widely known. However, the fauna of these northern, relatively pristine lakes has recently become threatened due to industrial development in the Arctic. In this study, the zoobenthos of 13 relatively large lakes and 9 small ponds was studied during the summer (July and August) from 2003 to 2013. The aim was to conduct

Glaciers support diverse ecosystems that are largely comprised of microbial life. However, at larger, macroscopic scales, glacier moss balls (sometimes called “glacier mice”) can develop from impurities on ice surfaces and represent a relatively rare biological phenomenon. These ovoid-shaped conglomerations of dirt and moss are only found on some glacier surfaces and provide key habitats for invertebrate

Marine tardigrades in the Antarctic and sub-Antarctic regions are poorly understood. During the 59th Japan Antarctic Research Expedition, a sediment sample was collected from Lützow-Holm Bay, East Antarctica. The sediment sample yielded three species of marine tardigrades belonging to the family Styraconyxidae Kristensen & Renaud-Mornant, 1983: Angursa antarctica Villora-Moreno, 1998, Styraconyx cf

We surveyed the distribution and diversity of fungi present in moss fairy rings from the South Shetland Islands. In the different islands accessed, the mosses Bartramia patens, Brachythecium austrosalebrosum, Bryum pseudotriquetrum, Pohlia nutans, Polytrichastrum alpinum, Sanionia uncinata, Syntrichia magellanica, and Syntrichia saxicola were infected with fairy rings. Among them, B. patens, B. pseudotriquetrum

Baleen, a unique oral α-keratin, has flat cortical layers enclosing hollow horn tubules. Baleen grows continuously to replace erosive loss from feeding-related wear. This is essential for maintaining efficient filtration over a whale’s long life history. Baleen fragments are seen in stomach contents and feces. We focused on fin (Balaenoptera physalus) and bowhead whales (Balaena mysticetus), but examined

Recent discoveries of high levels of biological activity in the Arctic marine ecosystems during the polar night raise questions regarding the ecophysiology of the pelagic postlarval daubed shanny Leptoclinus maculatus. Of special interest is the composition of the lipid sac—a unique feature not found in other Arctic fishes. Analysis of the fatty acid content of major classes of lipids as membrane—total

Polar cod (Boreogadus saida) is a key forage fish in the Arctic marine ecosystem and provides an energetic link between lower and upper trophic levels. Despite its ecological importance, spatially explicit studies synthesizing polar cod distributions across research efforts have not previously been conducted in its Pacific range. We used spatial generalized additive models to map the distribution of

To understand the recovery process and population dynamics of species that were severely depleted, it is essential to monitor their population size and habitat changes throughout their distribution. The South American sea lion (SASL, Otaria flavescens) provides an opportunity to investigate the process of a reduction from sealing and the subsequent recovery in a marine mammal species. Its abundance

An understanding of host–parasite interactions represents an important, but often overlooked, axis for predicting how polar marine biodiversity may be impacted by continued environmental change over the next century. Here, we survey three species of crocodile icefish (Notothenioidei: Channichthyidae) collected from two island archipelagos in the southern Scotia Arc region for evidence of leech infestations

The large hairy armadillo (Chaetophractus villosus) was introduced to the Isla Grande of Tierra del Fuego almost 35 years ago. Previous studies described the armadillo’s distribution relative to heated oil pipelines. The present study updates this distribution, and evaluates associations with additional environmental variables to better explain the dispersion process and to propose areas for the control/eradication

Macroalgae such as kelp are important ecosystem engineers in the Polar Regions and potentially affected by freshening and ocean warming. The endemic Arctic kelp Laminaria solidungula might be particularly imperiled and become locally extinct from Arctic fjord systems in the future, since temperature increase is most pronounced in the Polar Regions. Additionally, increased temperatures cause glacier

In vertebrates, developmental conditions can affect not only fledging success but also the phenotype of the offspring, with potential long-term consequences on adult performance. However, surprisingly the potential impact of anthropogenic disturbance on developing chicks is rarely investigated, notably in Antarctic wildlife. In this study, we specifically investigated the effects of repeated nest visits

The soundscape is an important habitat feature for marine animals, and climate change may cause large changes to the Arctic marine soundscape through sea ice loss and increased anthropogenic activity. We examined the marine soundscape over eight months near Ulukhaktok, Northwest Territories, Canada, and assessed the relative contribution of the geophony (wind and wave sounds), biophony (marine mammal

Abstract The conservation status of wild walruses (Odobenus rosmarus) is influenced by rapid warming of the Arctic, loss of seasonal sea ice, and increasing pressures related to anthropogenic activities and associated noise. Few data are available regarding acoustic sensitivity in walruses, although the species is known to be vulnerable to human disturbance. Here, we provide new information to describe

Abstract Information on the ecology of invertebrate communities populating Macrocystis pyrifera forests in the Falkland Islands is scarce. Indeed, the factors influencing diversity, distribution and community structure have never been studied here. Benthic photoquadrats were collected along three permanent 20 m transects at three depth strata (shallow 5–10 m; middle 10–15 m; deep 15–20 m) off the coast

Abstract The distribution of Atlantic cod (Gadus morhua) in northern Norwegian waters is expanding eastward and northward in the Barents Sea and along western Svalbard. In the Arctic fjords of Svalbard, cod has become abundant, but little is known about the biology, origin, or residence patterns of these populations. To address this issue, we used laser ablation inductively coupled plasma mass spectrometry

Abstract Characterizing the condition of fish in dynamic seasonal environments requires an understanding of their energy allocation strategies. Both polar cod (Boreogadus saida) and saffron cod (Eleginus gracilis) are important mid-trophic fish in Alaska Arctic waters, and changes in their lipid allocation could have important implications for their overwintering survival as well as their energetic

Abstract We characterized the diversity of cultivable fungal assemblages associated with the bryospheres of the bipolar mosses Polytrichastrum alpinum and Polytrichastrum juniperinum resident in King George Island, South Shetland Islands, Maritime Antarctica. From different parts of the mosses, 160 fungal isolates were obtained and identified using molecular biology methods as 43 taxa of 28 distinct

Abstract Antarctic dragonfishes (Bathydraconidae) of the suborder Notothenioidei are found only in the Southern Ocean where they diversified in habitats from the surface to the bathypelagic zone thousands of meters deep. Among dragonfishes, the pelagic Gymnodraconinae sister species Acanthodraco dewitti and Psilodraco breviceps remain poorly known. Although A. dewitti is thought to be restricted to

Abstract The current information about the diet composition of the rock shag (Phalacrocorax magellanicus) in the SW Atlantic coast comes mainly from conventional pellet or stomach content analysis from a few locations situated in northern Patagonia (Chubut Province, Argentina). In this work, we studied the diet of breeding rock shags over several years at a colony from southern Patagonia (Ría Deseado

Abstract The polar cod (Boreogadus saida) in the Barents Sea is one of the main stocks of this species in the Arctic, reaching a total biomass of almost 2 million tonnes in some years. It has been fluctuating considerably in abundance, and in recent years, it has been at a low level. Only small catches have been taken from the stock over the last four decades, and consequently, the observed variation

Abstract Declines in Arctic sea ice associated with climate change have resulted in habitat loss for ice-adapted species, while facilitating increased human development at higher latitudes. Development increases land-use and shipping traffic, which can threaten ecologically and culturally important species. Female polar bears (Ursus maritimus) and cubs are susceptible to disturbance during denning;

This correction stands to correct the original article. Due to a proofing oversight the article was published with an error in the Materials and Methods section. Specifically, the rendered, “feeding rate is 1 ± 0.2% of pooled living and drilled Limecola” should be replaced with “feeding rate is 21 ± 3.5% of pooled living and drilled Limecola”. According to the author group, this does not change the

Abstract The redfish species (genus Sebastes) are widely distributed across the North Atlantic and adjacent seas of the Arctic Ocean. It is also known that redfish sporadically occur in the White Sea as by-catches in targeted fisheries. However, to date, the information about species affinity, biology and ecology of the White Sea redfish is scarce and contradictory. Some researchers argued that redfish

Abstract Colossendeis megalonyx Hoek, 1881 has the broadest distribution of all sea spiders in the Southern Ocean. Previous studies have detected several evolutionarily young lineages within this taxon and interpreted them as a result of allopatric speciation in a few shelf refuges during glacial maxima. However, alternative scenarios such as ecological speciation in sympatry have rarely been considered

Abstract The ability of bottom-dwelling marine fauna to repair injured body parts is critical to the survival of individuals from disturbances that inflict wounds. The phylum Echinodermata, in particular, exposes a pronounced ability to regenerate skeletal damages. Regeneration of lost body parts of stellate echinoderms (crinoids, asteroids and ophiuroids) is a well-documented phenomenon, whereas sea

Abstract Harbor seals (Phoca vitulina) were formerly widely distributed in Greenland, but in most areas, they have now become rare or extinct. In this study, we deployed 15 satellite-linked data-recorders on 12 individual harbor seals captured near the southern tip of Greenland. The tagging site, a small archipelago, turned out to be their main haul-out and molting location. The seals were tagged around

Abstract There is growing evidence that increased Pacific water transport into the Arctic affects the marine ecosystem. One of the theoretical predictions for a future Arctic characterized by such environmental change is that subarctic taxa will expand northward and invade the native Arctic ecosystem. This study focuses on variation in macrofaunal community composition and the influence of changing

Abstract Previous paleolimnological investigations have examined the effects of gold mining operations, local land-use changes, and regional climate warming on the aquatic biota from shallow lakes in Yellowknife, Northwest Territories, Canada. However, the long-term impacts of these multiple environmental stressors on the biota of deeper lakes that support large-bodied fish species have not been investigated

Abstract The contribution of bird predation to the spatial variations in insect herbivory remains imperfectly understood, especially in Arctic ecosystems. We experimentally tested the hypothesis that the differences in insect herbivory between tundra and forest biomes, and between plant life-forms in these biomes, are associated with differences in the intensity of bird predation on defoliating insects

Abstract Antarctic minke whales Balaenoptera bonaerensis are rorquals that migrate to Antarctic waters to forage during the austral summer. Because the species frequents the edges of ice packs in summer, the potential impact of long-term physical environmental changes poses serious conservation concerns. Condition along the ice edge vary regionally, sometimes forming small ice free areas (ice gaps)

Abstract Lampreys are jawless fishes belonging to the order Petromyzontiformes. Geotria australis is the sole representative lamprey species of the Geotriidae family and is widely distributed around South America, Australia, New Zealand, and sub-Antarctic Islands. In South America, the presence and distribution of G. australis are well characterized in Western Patagonia, in rivers flowing into the

An increasing number of people are spending time in Polar Regions for work and tourism and this can increase the risk of tissue injuries, e.g. frostbite. The risk would be reduced if beneficial peripheral blood flow adaptions occurred but data regarding the trainability of the cold-induced vasodilation (CIVD) response are equivocal. Five healthy males spent almost 8 months in Antarctica; five of them

Although many notothenioid fishes are primarily carnivorous, some species consistently feed on macroalgae and are therefore omnivorous. Among fish, the degree of herbivory is usually reflected in the morphology of the gastrointestinal system especially intestine length. We examined a large number of juvenile and adult specimens of nine sympatric notothenioid species collected sequentially over eight

We discovered a new species of Porifera belonging to the genus Isodictya Bowerbank, 1864 during cruises aboard R/V Hesperides in Antarctica. Collected samples are mostly part of the surveys of the Spanish project BENTART whose main objective has been to study the benthic communities inhabiting sea bottoms of Livingston and Deception Island in the South Shetlands archipelago and the Antarctic Peninsula

The harsh environmental conditions of the ice-free regions of Continental Antarctica are considered one of the closest Martian analogues on Earth. There, rocks play a pivotal role as substratum for life and endolithism represents a primary habitat for microorganisms when external environmental conditions become incompatible with active life on rock surfaces, allowing life to spread throughout these

Rich in both microbial mat biomass and species diversity, the meltwater ponds of the McMurdo Ice Shelf (MIS) form important biodiversity and productivity elements in an otherwise barren landscape. These ponds are thought to be sensitive indicators of climate change-driven fluxes in pond water balance but our ability to predict such effects is confounded by our poor understanding of the inherent variability

Sea ice is an extreme environment known to host microbial communities which produce high concentrations of the metabolites dimethylsulfoniopropionate (DMSP) and dimethylsulfoxide (DMSO). These two compounds are involved in the cycling of the climate-cooling gas dimethylsulfide. Despite decades of research, the drivers of these large concentrations in sea ice remain largely unknown. In this study, we

Literature records of large actiniid sea anemones along the Atlantic coast of Canada currently include three Urticina species: U. felina, U. fecunda and U. crassicornis. The findings of the present morphological and molecular study conducted in eastern Newfoundland suggest that U. felina is often misidentified, and that this region may only harbor two similar-looking species: U. crassicornis and Cribrinopsis

Relatively little is known about the feeding ecology of grizzly bears (Ursus arctos) in Wapusk National Park. Other ursids, polar bears (Ursus maritimus), are well known predators of waterfowl nests in the area, and grizzly bears could feasibly make use of such resources. However, since the arrival of polar bears on land in the spring is largely dependent on date of sea-ice breakup, the timing of predation

To date, limited data are available on mercury (Hg) concentrations in Arctic benthos. It is important that we establish baseline Hg concentrations in benthic communities to improve our understanding of Hg within the Arctic marine ecosystem because they are food sources of key species, such as beluga whales, which are consumed by Inuit as a part of their traditional diet. In this study, we present Hg

Long-term studies are essential to determine demographic parameters and population trends in seabirds. However, studies to date have focused mainly on the larger and accessible species. While small seabirds (< 200 g) play a major role in marine ecosystems, their nesting habitat, which is typically fragile convoluted burrows, largely preclude long-term surveys. This study evaluated the installation

Despite being remote, polar and sub-polar regions are increasingly threatened by global ecological change. For instance, South America’s sub-Antarctic forest ecoregion is considered one of the world’s last wilderness areas and a global reference site for pre-Industrial Revolution nutrient cycles. Nonetheless, the North American beaver (Castor canadensis) was introduced to Tierra del Fuego in 1946 and

Nesting birds often respond to human disturbance as to a predatory act. In the case of the high Arctic, the disturbance of incubating birds may bring further complications due to egg cooling. In addition, it is assumed that birds in the high Arctic are not shy and do not respond to human presence fearfully. We tested how quickly the Arctic terns (Sterna paradisaea) nesting in two colonies in Svalbard

Rocky benthic communities are common in Antarctic coastal habitats; yet little is known about their carbon turnover rates. Here, we performed a broad survey of shallow ( < 65 m depth) rocky ice-scoured habitats of South Bay (Doumer Island, Western Antarctic Peninsula), combining (i) biodiversity assessments from benthic imaging, and (ii) in situ benthic dissolved oxygen (O2) exchange rates quantified

Understanding the physiology of non-native species in Antarctica is key to elucidating their ability to colonise an area, and how they may respond to changes in climate. Eretmoptera murphyi is a chironomid midge introduced to Signy Island (Maritime Antarctic) from South Georgia (Sub-Antarctic) where it is endemic. Here, we explore the tolerance of this species' egg masses to heat and desiccation stress

Knowledge of the life cycles of non-native species in Antarctica is key to understanding their ability to establish and spread to new regions. Through laboratory studies and field observations on Signy Island (South Orkney Islands, maritime Antarctic), we detail the life stages and phenology of Eretmoptera murphyi (Schaeffer 1914), a brachypterous chironomid midge introduced to Signy in the 1960s from

The long evolution of the Antarctic perciform suborder of Notothenioidei in the icy, oxygen-rich waters of the Southern Ocean may have reduced selective pressure to maintain a hypoxic response. To test this hypothesis, cDNA of the key transcriptional regulator of hypoxic genes, hypoxia-inducible factor-1α (HIF-1α), was sequenced in heart ventricles of the red-blooded notothenioid, Notothenia coriiceps

One of the recently recognised stressors in Arctic ecosystems concerns plastic litter. In this study, juvenile polar cod (Boreogadus saida) were investigated for the presence of plastics in their stomachs. Polar cod is considered a key species in the Arctic ecosystem. The fish were collected both directly from underneath the sea ice in the Eurasian Basin and in open waters around Svalbard. We analysed

Under-ice blooms of phytoplankton in the Chukchi Sea have been observed, with strong implications for our understanding of the production regimes in the Arctic Ocean. Using a combination of satellite remote sensing of phytoplankton biomass, in situ observations under sea ice from an autonomous underwater vehicle (AUV), and in vivo photophysiology, we examined the composition, magnitude and origin of

In a changing climate, Arctic streams are expected to show more influence from snowmelt, rainfall and groundwater, and less domination from glacial meltwater sources. Snowmelt streams are characteristic features of Arctic ecosystems, yet our current understanding of longitudinal patterns in benthic macroinvertebrate assemblages in these systems is limited when compared to glacier-fed systems. This

Fish skeletal muscle is often used to monitor mercury concentrations and is used by regulatory agencies to develop fish consumption advisories. However, the distribution of mercury species (MeHg+ and THg) in muscle tissue and other organs is not well understood in a number of fish species. Here we evaluate the spatial distribution of THg and MeHg+ in skeletal muscle and internal organs (heart, liver

The sea ice cover of the Arctic Ocean has changed dramatically in the last decades, and the resulting consequences for the sea-ice-associated ecosystem remain difficult to assess. Algal aggregates underneath sea ice are of great importance for the ice-associated ecosystem and the pelagic-benthic coupling. However, the frequency and distribution of their occurrence is not well quantified. During the