Whale carcasses on the seafloor support unique, ephemeral communities of organisms, and ‘natural’ whale fall sites are infrequently encountered, especially in polar regions. During a manned submersible dive in early 2017, we discovered the skeleton of an Antarctic minke whale (Balaenoptera bonaerensis) at 963 m in Palmer Deep, in the Western Antarctic Peninsula. The site was filmed in HD for approximately two hours, enabling visual identification of representatives from at least eight phyla, although physical sampling was not possible. The remains appeared to be in the late ‘enrichment–opportunistic’ phase (although some mobile scavengers were still present and some sulfonic activity had already commenced), with polychaetes of the order Aciculata, and family Ampharetidae, plus several amphipod species, most abundant. Novel eusirid amphipod and rhodaliid siphonophore taxa were also present. The observed faunal distribution suggests patterns consistent with reports from other Antarctic whale falls (both experimental and natural). This discovery represents the highest-latitude natural whale fall reported to date.

Shallow waters, little-studied in Continental Antarctica, among other micrometazoans host bdelloid rotifers, which diversity, ecology, and distributional patterns in turn are poorly known. To address these issues, we analysed plankton samples collected during the 2018/2019 season in the Thala Hills oasis (East Antarctica), in shallow freshwater lakes and temporary ponds that formed during intense snow melting in December–January. Bdelloids were present in more than 90% of the sites with nine species revealed. The most frequent were Antarctic endemics [Philodina gregaria (P. gregaria), Adineta grandis (A. grandis), and Adineta coatsi (A. coatsi)], while some non-abundant bdelloids either provide characteristics of widely distributed taxa or require further taxonomy studies as they can be species new for the science. The abundance of bdelloids varied greatly across studied sites and localities, with a maximum of more than 700,000 ind m−3 and an increasing tendency to be more numerous in rock-basin temporary ponds, compared to larger lakes, with variability for different taxa. The environmental parameters strongly explain the bdelloid distribution (78.4% of the variation), with the most important factors being the type of bottom (9.9%), altitude (8.0%), TDS (6.6%), and salinity (6.5%). The cyanobacterial mats from the bottom didn’t contribute much to bdelloid distributional patterns, despite being known to be a preferred habitat for micrometazoans including rotifers. These results shape a perspective to study the processes of the formation of Antarctic seasonal aquatic habitats settled by organisms, which demonstrate an ecomorphological range from planktonic organisms to crawling ‘scrapers’.

In recent years, functional changes in Southern Ocean are becoming more noticeable, due to climate change and increasing human impacts, including a growing fishery that is concentrating in the Antarctic Peninsula (AP) region. Antarctic krill Euphausia superba is often the primary prey species for animals such as Pygoscelis penguins, a sentinel species for ecosystem monitoring and management. During the last two decades in the AP gentoo penguin numbers (Pygoscelis papua) have increased and their range has shifted southward, in contrast to the decline in numbers of Adélie (P. adeliae) and chinstrap (P. antarcticus) penguins. Given divergent population trends, the goal of this study was to examine differences in their diet, and size structure of Antarctic krill recovered from penguin diet samples. The study is based on diet samples collected during the austral summers on King George Island (South Shetland Islands) where P. adeliae, P. antarcticus, and P. papua breed in mixed colonies. Results indicate that the penguins consumed krill of similar sizes during the breeding period. In contrast to prior diet studies, we found higher proportions of krill in the gentoo diet and changes in the percentage of krill in the diet relative obtained during 1970s. The similarity in diets among all three species suggests that the availability prey items (e. g., fishes) may be changing and driving higher dietary overlap. Moreover, we also check differences in krill length among penguin individuals and we did not find any statistically significant differences. We also found plastic debris in penguin stomachs during both summers.

Antarctic notothenioid fishes are recognised as one of the rare examples of adaptive radiation in the marine system. Withstanding the freezing temperatures of Antarctic waters, these fishes have diversified into over 100 species within no more than 10–20 million years. However, the exact species richness of the radiation remains contested. In the genus Channichthys, between one and nine species are recognised by different authors. To resolve the number of Channichthys species, genetic information would be highly valuable; however, so far, only sequences of a single species, C. rhinoceratus, are available. Here, we present the nearly complete sequence of the mitochondrial genome of C. rugosus, obtained from a formalin-fixed museum specimen sampled in 1974. This sequence differs from the mitochondrial genome of C. rhinoceratus in no more than 27 positions, suggesting that the two species may be synonymous.

Wolverines (Gulo gulo) occupy most of the globe’s Arctic tundra. Given the rapidly warming climate and expanding human activity in this biome, understanding wolverine ecology, and therefore the species’ vulnerability to such changes, is increasingly important for developing research priorities and effective management strategies. Here, we review and synthesize knowledge of wolverines in the Arctic using both Western science sources and available Indigenous Knowledge (IK) to improve our understanding of wolverine ecology in the Arctic and better predict the species’ susceptibility to change. To accomplish this, we update the pan-Arctic distribution map of wolverines to account for recent observations and then discuss resulting inference and uncertainties. We use these patterns to contextualize and discuss potential underlying drivers of distribution and population dynamics, drawing upon knowledge of food habits, habitat associations, and harvest, as well as studies of wolverine ecology elsewhere. We then identify four broad areas to prioritize conservation and research efforts: (1) Monitoring trends in population abundance, demographics, and distribution and the drivers thereof, (2) Evaluating and predicting wolverines’ responses to ongoing climate change, particularly the consequences of reduced snow and sea ice, and shifts in prey availability, (3) Understanding wolverines’ response to human development, including the possible impact of wintertime over-snow travel and seismic testing to reproductive denning, as well as vulnerability to hunting and trapping associated with increased human access, and (4) Ensuring that current and future harvest are sustainable.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00300-022-03079-4.