The coastal region of the Western Antarctic Peninsula is considered a biological hotspot with high levels of phytoplankton productivity and krill biomass. Recent in situ observations and particle modeling studies of Palmer Canyon, a deep bathymetric feature in the region, demonstrated the presence of a recirculating eddy that traps particles, retaining a distinct particle layer...
The slender scalyhead Trematomus lepidorhinus and the scaly rockcod T. loennbergii are closely related species with similar streamlined body morphology, epibenthic lifestyle and ecological niche. They are distributed in relatively deep waters on the continental shelf and slope of the Weddell Sea, although with some differences in preferential depth of occurrence. As previously...
Pathogens affecting Antarctic fishes remain mostly unknown and are largely limited to the description of macroparasites such as leeches and endoparasitic worms. Fish, however, occupy a crucial role in the functioning of the Antarctic ecosystem and deterioration of their health can alter the entire Antarctic food chain. In recent years, several studies have identified novel...
Leopard seals (Hydrurga leptonyx) occur mainly south of the Antarctic Polar Front, but immatures, in particular, seasonally move beyond this range during the austral winter and spring, typically under increased sea ice conditions. Extralimital occurrences of leopard seals can be observed at several sub-Antarctic islands where they haul out to rest. We present new records of...
The interaction between climate change and anthropogenic activities in Antarctica is facilitating the invasion of temperate microorganisms into its aquatic ecosystems, including toxic species that could impact these ecosystems. This review aims to identify the toxic cyanobacteria and microalgae species detected thus far in sub-Antarctic and Antarctic waters and to explore long...
Factors shaping biodiversity and functioning of coastal ecosystems in Antarctica are still largely unknown due to the overlap of multiple physical and bio-ecological forcings. Here, we investigated three coastal areas of the Ross Sea (Antarctica) across a coast-offshore transect (25–140 m depth), including an area located in front of the longest-dwelling penguin colony of the...
The bowhead whale (Balaena mysticetus) is the only baleen whale endemic to the Arctic and has been greatly depleted through commercial whaling. Two bowhead whales were photographed swimming together in the Churchill River estuary, Manitoba, Canada, in 2020 using a time-lapse camera mounted at the port of Churchill. A systematic literature review of bowhead whale sightings off the...
Benthic communities have a key function in the Antarctic marine ecosystem since they play a central role in the food web pathway and represent the main “environmental biological memory”. The goal of the study is to evaluate differences in macrozoobenthic community structure, along the Antarctic coasts of Tethys Bay (Ross Sea), potentially affected by two types of pressures...
Antarctic soils are unique from those found nearly anywhere else on Earth yet can still harbor a broad diversity of microorganisms able to tolerate the challenging conditions typical of the continent. For these reasons, microbiologists have been drawn to Antarctica for decades. However, our understanding of which microbes thrive in Antarctic soils and how they to do so remains...
Bacterial endophytes reside in plant tissues and can promote plant growth under abiotic stresses. Complex microbial communities are associated with cold-adapted plants, but scarce information is available on the functional properties of Antarctic bacterial endophytes. This study aimed to investigate possible cold tolerance and plant growth promotion activities of two Antarctic...
Dispersant has been used effectively to enhance biodegradation rate of spilled oil in marine environment even at low temperature. However, the introduction of new ultra-low sulfur fuel oils (LSFO) to meet the new regulation for sulfur emission from ships, poses new challenges for oil spill response. There is limited knowledge regarding the dispersibility of the new oil type when...
Environmental DNA (eDNA) is frequently used to infer distributions of microorganisms in Antarctica. Their distributions relative to environmental variables are, in turn, sometimes used to infer their physiological range (and a relationship between the two is generally assumed for conservation purposes). We sought to determine whether ecological inferences based on distributions...
Antarctica, one of the most rapidly changing places on the planet due to global climate change, hosts an impressive diversity of marine fauna. Previous efforts have recognized 23 ecoregions around the Antarctic. However, most of our understanding of the Southern Ocean’s benthic communities is based on more accessible regions (e.g. Antarctic Peninsula) or near established research...
Cephalopods are crucial to the Southern Ocean ecosystem, connecting top predators with mid-trophic organisms, yet their ecology in the Pacific sector is not well understood. This research used stable isotope analysis to explore the habitat and trophic ecology of cephalopods found in the diet of eastern rockhopper penguins (Eudyptes chrysocome filholi) around Campbell Island, a...
The rapid diversification of notothenioid fishes in Antarctic waters is a prime example of the process of adaptive radiation. Within around 10 million years, Antarctic notothenioids have diversified into over 100 species with a broad range of lifestyles and ecological adaptations. However, the exact number of species within this radiation has long been unclear. Particularly...
Monitoring of sentinel species provides insight into the ecosystems in which they live. In the Southern Ocean, penguins are one such indicator species, where only a limited number of colonies have been monitored extensively for decades around Antarctica. As the Southern Ocean warms and commercial fishing continues, the need for expansion of population monitoring has become...
Arctic sea ice has provided a historical barrier for killer whale (Orcinus orca) entry, but that barrier is now depleting as the sea ice melts due to global climate change. This study used passive acoustic monitoring to describe changes in broad-scale killer whale presence in the U.S. Arctic associated with declining sea ice. Passive acoustic data were analyzed for killer whale...
iKaluk, Inuttitut for Arctic charr (Salvelinus alpinus), holds significant commercial and cultural value for Inuit communities throughout Nunatsiavut. Studies evaluating iKaluk habitat associations in freshwater are plentiful; however, there is limited information on the ecological makeup and sediment characteristics of anadromous charr habitats in marine environments. This study...
We analysed unpublished data on territory size and tenure in adult male sub-Antarctic fur seals Arctocephalus tropicalis recorded at Gough Island, Southern Ocean, during the 1975/76 austral summer breeding season. Adult males (n=15) remained on their territories for between 35–56 days (mean 45.4±6.7 days). Territory size during the peak breeding season was 21.9 m2 on average (n...
Knowledge of the spatial distribution of many polar seabird species is incomplete due to the remoteness of their breeding locations. Here, we compiled a new database of published and unpublished records of all known snow petrel Pagodroma nivea breeding sites. We quantified local environmental conditions at sites by appending indices of climate and substrate, and regional-scale...
Rare meiofauna taxa are often indicators of specific environmental conditions. A new and rare species of Entoprocta from the Southern Ocean, its abundance, habitat and possible commensal relationship with Polychaeta are presented. During the RV Polarstern expedition PS118 (2019) to the northwestern Weddell Sea, sediment samples were taken with a multicorer. The species of the...
There are increasing concerns about regional ecosystem shifts in the Arctic due to climate change. Notably, warming-induced increases in Arctic vegetation cover can have important consequences for surface energy balance, habitat changes, permafrost, and more. Mammalian herbivory is an important potential force to counteract this effect. In this systematic literature review, we...
Gelatinous zooplankton (GZ), play a crucial role in marine food webs, nutrient cycling, and carbon sequestration, however, quantifying their abundances remains challenging due to their delicate body structure, complex life cycles and variable population dynamics. Their tendency to form sporadic, large-scale aggregations further complicate the differentiation between true...
In the Southern Ocean, myctophids (family Myctophidae) are speciose, dominate the mesopelagic fish biomass, and are important in the diets of many fishes, squids, seabirds, and marine mammals. Consequently, they play a key role in carbon export and energy transfer from primary consumers to top predators. However, they are delicate and rarely found intact in predator stomachs...
The diversity of bacteria associated with lichens has received increasing attention. However, studies based on next-generation sequencing of microbiomes have not yet been conducted in the Arctic and Subarctic regions. In this study, rock-dwelling lichens belonging to the Umbilicariaceae family were sampled from the Arctic and Subarctic biological zones. The primary research...