Recent molecular evidence suggests a global distribution of marine fungi; however, the ecological relevance and corresponding biological contributions of fungi to marine ecosystems remains largely unknown. We assessed fungal biomass from the open Arctic Ocean by applying novel biomass conversion factors from cultured isolates to environmental sterol and CARD-FISH data. <br>We found an average of ...

Arctic sea ice contains a substantial amount of living biota of which part is lost through melt and export out of the Arctic Ocean every year. It is unclear how populations can be maintained within the Arctic Ocean. A representative ice inhabitant, the amphipod Apherusa glacialis was previously assumed to spend its entire life in the sea ice habitat, hence being dependent on sea ice to complete ...

Changes in vertical and spatial distributions of zooplankton and small pelagic fish impact the biological carbon pump and the distribution of larger piscivorous fish and marine mammal species. However, their distribution and abundance remain poorly documented at high latitudes because of the difficulties inherent to sampling relatively fast-moving organisms in ice-covered waters. This study documents ...

The Bering Sea has some of the highest concentrations of inorganic nutrients of any marine system. In the Bering Sea, eukaryotic microbes interface inorganic nutrient sequestration and cycling processes that drive one of the most productive ecosystems globally. Historical surveys of eukaryotic microbial diversity in the Bering Sea have relied on microscopy and culturing-dependent analyses to assess ...

Sea-ice declines in the European Arctic have led to substantial changes in marine food webs. To better understand the biological implications of these changes, we quantified the contributions of ice-associated and pelagic carbon sources to the diets of Arctic harp and ringed seals using compound-specific stable isotope ratios of fatty acids in specific primary producer biomarkers derived from sea-ice ...

Microalgae have unique adaptions including low metabolic activity, utilization of lipid storage, and resting stage formation to survive the Polar Night. Some species are mixotrophic or heterotrophic and do survive periods that are not favorable for photosynthetic (autotrophic) growth, such as the Polar Night. In addi- tion, the autotrophic and mixotrophic species seem to maintain the key components ...

The net productivity of sea ice is determined by the physical and geochemical characteristics of the ice–ocean system and the activity of organisms inhabiting the ice. Differences in habitat suitability between first-year and multi-year sea ice can affect the ice algal community composition and acclimation state, introducing considerable variability to primary production within each ice type. In ...

<i>Apherusa glacialis</i> is a common, sea ice-associated amphipod found throughout the Arctic Ocean and has long been considered permanently associated with the sea ice habitat. However, pelagic occurrences of <i>A. glacialis</i> have also been reported. It was recently suggested that <i>A. glacialis</i> overwinters at depth within the Atlantic-water inflow near Svalbard, to avoid being exported ...

Arctic sea ice provides microhabitats for biota that inhabit the liquid‐filled network of brine channels and the ice–water interface. We used meta‐analysis of 23 published and unpublished datasets comprising 721 ice cores to synthesize the variability in composition and abundance of sea ice meiofauna at spatial scales ranging from within a single ice core to pan‐Arctic and seasonal scales. Two‐thirds ...

The Arctic is experiencing dramatic changes including increases in precipitation, glacial melt, and permafrost thaw, resulting in increasing freshwater runoff to coastal waters. During the melt season, terrestrial runoff delivers carbon- and nutrient-rich freshwater to Arctic coastal waters, with unknown consequences for the microbial communities that play a key role in determining the cycling and ...