Benthic remineralization under future Arctic conditions and evaluating the potential for changes in carbon sequestration in warming sediments.

Benthic (seafloor) remineralization of organic material determines the fate of carbon in the ocean and its sequestration. Bottom water temperature and labile carbon supply to the seafloor are expected to increase in a warming Arctic and correspondingly, benthic remineralization rates. We provide some of the first experimental data on the response of sediment oxygen demand (SOD), an established proxy for benthic remineralization, to increased temperature and/or food supply across a range of Arctic conditions and regimes.

High uptake of sympagic organic matter by benthos on an Arctic outflow shelf.

On Arctic shelves, benthic food-webs are tightly linked to overlying primary production. In the seasonal ice zone, sympagic (ice-associated) primary production can be a major source of carbon for the benthos on productive inflow shelves. However, the role of sympagic organic matter is less well-understood in food webs of heavily ice-covered, less- productive outflow shelves, such as the northeast Greenland shelf.

Measuring ecological quality status in low-diversity Arctic intertidal foraminiferal assemblages using a diversity-based index.

EcoQS assessment of the marine intertidal zone based on its fauna is challenging because the assemblages have a low diversity and consist of stress tolerant species. The new approach we propose is to pool foraminiferal diversity (effective number of species exp(H')) across the whole intertidal zone including the salt marsh and tidal flat. In seven fjordheads studied in northern Fennoscandia, polycyclic aromatic hydrocarbon (PAH) concentrations indicated low levels of pollution (EcoQS Excellent to Moderate).

Evaluation of zootechnical parameters of piglets born and suckled from dams treated with a non-steroidal anti-inflammatory drug after farrowing.

Background: Farrowing is a precarious moment in pig production potentially associated with a wide range of ailments in sows and gilts, and often having a negative impact on pre-weaned piglet zootechnical performances.

Aim: To evaluate zootechnical parameters of piglets born and suckled from dams treated postpartum with tolfenamic acid (TA) at a commercial farm.

Methods: Dams were randomized to receive an intramuscular injection of 4% TA at 2 mg/kg body weight within 12 hours postpartum (TA group) or no inflammatory treatment (control group).

Horizon scanning of potential threats to high-Arctic biodiversity, human health and the economy from marine invasive alien species: A Svalbard case study.

The high Arctic is considered a pristine environment compared with many other regions in the northern hemisphere. It is becoming increasingly vulnerable to invasion by invasive alien species (IAS), however, as climate change leads to rapid loss of sea ice, changes in ocean temperature and salinity, and enhanced human activities. These changes are likely to increase the incidence of arrival and the potential for establishment of IAS in the region.

Seafloor warm water temperature anomalies impact benthic macrofauna communities of a high-Arctic cold-water fjord.

Amid the alarming atmospheric and oceanic warming rates taking place in the Arctic, western fjords around the Svalbard archipelago are experiencing an increased frequency of warm water intrusions in recent decades, causing ecological shifts in their ecosystems. However, hardly anything is known about their potential impacts on the until recently considered stable and colder northern fjords. We analyzed macrobenthic fauna from four locations in Rijpfjorden (a high-Arctic fjord in the north of Svalbard) along its axis, sampled intermittently in the years 2003, 2007, 2010, 2013 and 2017.

Reduced efficiency of pelagic-benthic coupling in the Arctic deep sea during lower ice cover.

Pelagic-benthic coupling describes the connection between surface-water production and seafloor habitats via energy, nutrient and mass exchange. Massive ice loss and warming in the poorly studied Arctic Chukchi Borderland are hypothesized to affect this coupling. The strength of pelagic-benthic coupling was compared between 2 years varying in climate settings, 2005 and 2016, based on δC and δN stable isotopes of food-web end-members and pelagic and deep-sea benthic consumers.

Isotopic turnover in polar cod (Boreogadus saida) muscle determined through a controlled feeding experiment.

Polar cod (Boreogadus saida) is an important trophic link within Arctic marine food webs and is likely to experience diet shifts in response to climate change. One important tool for assessing organism diet is bulk stable isotope analysis. However, key parameters necessary for interpreting the temporal context of stable isotope values are lacking, especially for Arctic species.

Limited predatory effects on infaunal macrobenthos community patterns in intertidal soft-bottom of Arctic coasts.

Predation shapes marine benthic communities and affects prey species population dynamics in tropic and temperate coastal systems. However, information on its magnitude in systematically understudied Arctic coastal habitats is scarce. To test predation effects on the diversity and structure of Arctic benthic communities, we conducted caging experiments in which consumers were excluded from plots at two intertidal sedimentary sites in Svalbard (Longyearbyen and Thiisbukta) for 2.

Telemetry data of red king crab () migrations in a north Norwegian fjord.

Acoustic telemetry allows for high-resolution, long-term tracking of moving animals. Here, we describe data on the movement patterns of 37 adult red king crab (RKC, ) obtained by means of acoustic telemetry. Acoustically tagged RKC were released in Gamvikfjorden (Sørøya, northern Norway) the 24th of May 2016 and tracked until the 1st of November 2016.

Seasonal dynamics of mesozooplankton biomass over a sub-Arctic continental shelf.

Mesozooplankton research in high latitude ecosystems tends to focus on different life stages of spp. due to its biomass dominance and trophic roles. However, a complex seasonal succession of abundant smaller mesozooplankton taxa suggests that the ecological functioning of the mesozooplankton communities is more complicated.

Distribution and ecology of polar cod (Boreogadus saida) in the eastern Barents Sea: A review of historical literature.

The polar cod (Boreogadus saida) has a circumpolar distribution and is the most abundant planktivorous fish in the Arctic. Declining sea-ice coverage impacts polar cod directly and also facilitates expansion of human activities in the region leading to increasing anthropogenic pressures on biota. Here we summarize current data and knowledge on polar cod from the Russian sector of the Barents Sea and discuss knowledge needs for the management of polar cod under changing environmental conditions and anthropogenic impacts.

Summer and winter MgCO levels in the skeletons of Arctic bryozoans.

In the Arctic, seasonal patterns in seawater biochemical conditions are shaped by physical, chemical, and biological processes related to the alternation of seasons, i.e. winter polar night and summer midnight sun.

Climate change and diminishing seasonality in Arctic benthic processes.

The iconic picture of Arctic marine ecosystems shows an intense pulse of biological productivity around the spring bloom that is sustained while fresh organic matter (OM) is available, after which ecosystem activity declines to basal levels in autumn and winter. We investigated seasonality in benthic biogeochemical cycling at three stations in a high Arctic fjord that has recently lost much of its seasonal ice-cover. Unlike observations from other Arctic locations, we find little seasonality in sediment community respiration and bioturbation rates, although different sediment reworking modes varied through the year.

Artificial light during the polar night disrupts Arctic fish and zooplankton behaviour down to 200 m depth.

For organisms that remain active in one of the last undisturbed and pristine dark environments on the planet-the Arctic Polar Night-the moon, stars and aurora borealis may provide important cues to guide distribution and behaviours, including predator-prey interactions. With a changing climate and increased human activities in the Arctic, such natural light sources will in many places be masked by the much stronger illumination from artificial light. Here we show that normal working-light from a ship may disrupt fish and zooplankton behaviour down to at least 200 m depth across an area of >0.

Latitudinal consistency of biomass size spectra - benthic resilience despite environmental, taxonomic and functional trait variability.

Global warming is expected to cause reductions in organism body size, a fundamental biological unit important in determining biological processes. Possible effects of increasing temperature on biomass size spectra in coastal benthic communities were investigated. We hypothesized higher proportions of smaller size classes in warmer conditions.

Hydrocarbon molecular markers in the Holocene bottom sediments of the Barents Sea as indicators of natural and anthropogenic impacts.

The recent intensification of energy resource exploration and human activities in the Barents Sea (BS) requires a more thorough assessment of the natural and anthropogenic impact of hydrocarbons on the environment. We analyzed a wide set of sensitive indicators, including hydrocarbon molecular markers and organic matter (OM) maturity parameters in the Holocene sediments from three regions of the BS: the Kola-Kanin Monocline (KKM), the Svalbard shelf, and the Shtokman gas-condensate field (GCF). An increase in pyrogenic polycyclic aromatic hydrocarbons toward the core surface traces the intensification of anthropogenic contamination in the KKM region during last century.

Benthic macrofaunal bioturbation activities from shelf to deep basin in spring to summer transition in the Arctic Ocean.

The aim of this study was to assess bioturbation rates in relation to macrozoobenthos and environmental variables in the Svalbard fjords, Barents Sea and Nansen Basin during spring to summer transition. The results showed differences in benthic community structure across sampled area in relation to sediment type and phytopigment content. Fjords, Barents Sea and the shallow parts of Nansen Basin (<400 m) were characterized by high functional groups diversity, and by biodiffusive and non-local rates ranging from 0.

Effects of an in situ diesel oil spill on oxidative stress in the clam Anomalocardia flexuosa.

Intensive exploitation and transport of oil and derivatives are increasing the risk of coastal contamination by either dramatic disasters or diffuse sources. Tools for monitoring diffuse contamination, such as diesel oil that leaks from marine vessels are much needed. We experimentally tested the efficiency of antioxidant biomarkers as indicators of chronic exposure to diesel oil in a mudflat from the subtropical Bay of Paranaguá, in southern Brazil.

Baseline levels of oxidative stress biomarkers in species from a subtropical estuarine system (Paranaguá Bay, southern Brazil).

Offshore petroleum exploration has increased the risks of oil spills in coastal tropical and subtropical habitats. Monitoring tools are needed to assess and protect environmental health. We determined baseline values of antioxidant biomarkers (CAT, SOD, GPx, GST, MDA) for five ecologically relevant species in a subtropical system in southern Brazil.

Unexpected Levels of Biological Activity during the Polar Night Offer New Perspectives on a Warming Arctic.

The current understanding of Arctic ecosystems is deeply rooted in the classical view of a bottom-up controlled system with strong physical forcing and seasonality in primary-production regimes. Consequently, the Arctic polar night is commonly disregarded as a time of year when biological activities are reduced to a minimum due to a reduced food supply. Here, based upon a multidisciplinary ecosystem-scale study from the polar night at 79°N, we present an entirely different view.

Is Ambient Light during the High Arctic Polar Night Sufficient to Act as a Visual Cue for Zooplankton?

The light regime is an ecologically important factor in pelagic habitats, influencing a range of biological processes. However, the availability and importance of light to these processes in high Arctic zooplankton communities during periods of 'complete' darkness (polar night) are poorly studied. Here we characterized the ambient light regime throughout the diel cycle during the high Arctic polar night, and ask whether visual systems of Arctic zooplankton can detect the low levels of irradiance available at this time.

Arctic complexity: a case study on diel vertical migration of zooplankton.

Diel vertical migration (DVM) of zooplankton is a global phenomenon, characteristic of both marine and limnic environments. At high latitudes, patterns of DVM have been documented, but rather little knowledge exists regarding which species perform this ecologically important behaviour. Also, in the Arctic, the vertically migrating components of the zooplankton community are usually regarded as a single sound scattering layer (SSL) performing synchronized patterns of migration directly controlled by ambient light.

Benthic community structure, diversity, and productivity in the shallow Barents Sea bank (Svalbard Bank).

The Barents Sea is among the most productive areas in the world oceans, and its shallow banks exhibit particularly high rates of primary productivity reaching over 300 g C myear. Our study focused on the Svalbard Bank, an important feeding area for fishes and whales. In order to investigate how benthic community structure and benthic secondary production vary across environmental gradients and through time, we sampled across the bank and compared results with a similar study conducted 85 years ago.