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Sleep architecture, periodic breathing and mood disturbance of expeditioners at Kunlun Station (4087 m) in Antarctica
Get PDFSeveral studies have reported the detrimental impacts of hypoxia exposure on sleep. Chinese Kunlun Station (altitude 4087 m) is located at Dome A, the highest point on the Antarctic ice sheet and one of the most extreme environments on Earth. This study investigated alteration of sleep, breathing and mood status in healthy expeditioners at Kunlun Station at Dome A. The study examined 10 male volunteers of the inland transverse party to Kunlun Station during the 31st Chinese National Antarctic Research Expedition, and valid data from eight volunteers were analyzed. Sleep structure, breathing pattern and mood were monitored using portable polysomnography (PSG) and profile of mood state (POMS) at two time points: (1) at Zhongshan Station (10 m) before departure to Kunlun Station; (2) on nights 12 –13 of residence at Kunlun Station. Slow-wave sleep (Stage 3 non-rapid eye movement) was markedly reduced at Kunlun Station (P < 0.01). Total sleep time, sleep efficiency and sleep latency showed no significant changes. Total respiratory events (P < 0.05), apnea/hypopnea index (AHI) (P < 0.05) and hypopnea index (P < 0.01) substantially increased at Kunlun Station. The most common respiratory disorder was periodic breathing, occurring almost exclusively during non-rapid eye movement sleep. The oxygen desaturation index increased markedly (P < 0.05), while nocturnal oxygen saturation dramatically fell at Kunlun Station (P < 0.05). Vigor scores decreased at Kunlun Station (P < 0.05). Expeditioners exhibited reduced slow wave sleep, induced periodic breathing, decreased oxygen saturation and decreased vigor at Kunlun Station
Approximating home ranges of humpback and fin whales in Drake Passage and Antarctica
Get PDFIdentifying home ranges—those areas traversed by individuals in their normal foraging, mating, and parenting activities—is an important aspect of cetacean study. Understanding these ranges facilitates identification of resource use and conservation. Fin and humpback whales occur in Antarctica during the austral summer, but information regarding their home ranges is limited. Using opportunistically collected whale sighting data from eight consecutive summer seasons spanning 2010–2017, we approximate the home ranges of humpback and fin whales around Drake Passage (DRA), West of Antarctic Peninsula (WAP), South Shetland Islands (SSI), an area northwest of the Weddell Sea (WED), and around the South Orkney Islands (SOI). Approximate home ranges are identified using Kernel Density Estimation (KDE). Most fin whales occurred north and northwest of the SOI, which suggests that waters near these islands support concentrations of this species. Most humpback whales were observed around the SSI, but unlike fin whales, their distributions were highly variable in other areas. KDE suggests spatial segregation in areas where both species exist such as SOI, SSI, and WPA. Partial redundancy analysis (pRDA) suggests that the distributions of these species are more affected by spatial variables (latitude, longitude) than by local scale variables such as sea surface temperature and depth. This study presents a visual approximation of the home ranges of fin and humpback whales, and identifies variation in the effects of space and environmental variables on the distributions of these whales at different spatial scales
Effects of the sunscreen ultraviolet filter, oxybenzone, on green microalgae
Get PDFUltraviolet (UV) filters are widely used in sunscreen and personal care products due to their ability to give protection to our skin from UV radiation. Oxybenzone, commonly known as benzophenone-3, is one type of UV filter found as the active ingredient in many pharmaceutical products. Although oxybenzone has been extensively studied as an environmental toxicant in the ecosystem, little is known about its toxicity effects on microalgae. The effects of oxybenzone on growth (measured as OD620 nm, chl ɑ and carotenoids) and macromolecular composition of polar microalgae (Chlorella UMACC 400 and Chlorella UMACC 401) and temperate microalgae (Chlorella sp., Chlamydomonas reinhardtii, Scenedesmus quadricauda) were investigated. These microalgae were cultured in triplicate and exposed to different oxybenzone concentrations (0, 100, 200, 300 and 400 mg·L−1), at 4 ℃ and 18 ℃ for polar and temperate species respectively, for 96 h. The oxybenzone concentrations used represent a range from environmental to extreme concentrations to understand the impact of this toxicant on microalgae. The results showed that the highest concentration of oxybenzone (300 and 400 mg·L−1) had adverse effects on growth rate and biomass of these microalgae. However, exposure to oxybenzone concentrations ranging from 200 mg·L−1 to 400 mg·L−1 did not have significant effects on S. quadricauda growth. The exposure to oxybenzone at higher concentrations also led to changes in cell structure after 96 h. Generally, protein and carbohydrate content of all microalgae except S. quadricauda increased with increasing oxybenzone concentrations. Protein content increased significantly when cells were exposed to oxybenzone, though effects were greater in the polar species, suggesting that it could be one of the adaptive strategies that enabled these microalgae to tolerate oxybenzone. Further investigation is required to determine the effects of oxybenzone on other features of microalgal performance at relevant environmental concentrations
Spatial variation in grain-size population of surface sediments from northern Bering Sea and western Arctic Ocean: implications for provenance and depositional mechanisms
Get PDFIn general, sediments in nature comprise populations of various diameters. Accurate information regarding the sources and depositional mechanisms of the populations can be obtained through their temporal and spatial comparisons. In this study, the grain size distribution of surface sediments from the Bering Sea and western Arctic Ocean were fitted and partitioned into populations using a log-normal distribution function. The spatial variations in the populations indicate differences in their sources and deposition mechanisms. The sediments on most of the Bering Sea Shelf originated from the Yukon River, and were transported westward by waves and currents. However, the presence of a coarser population outside Anadyr Bay was the result of Anadyr River transport. Additionally, a northward transport trend of fine suspended particles was observed on the west side of the Bering Sea Shelf. The sediments in Hope Valley in the south Chukchi Sea also originated from the Yukon River. The coarser population on the central Chukchi Sea Shelf originated from coast of Alaska to the east, not the Yukon River, and was transported by sea ice and bottom brine water. The populations of sediments from the Chukchi Basin and the base of the Chukchi Sea Slope are the result of sea ice and eddy action. Surface sediments from the western high Arctic Ocean predominantly comprised five populations, and two unique populations with mode diameters of 50–90 μm and 200–400 μm, respectively, were ubiquitous in the glacial and interglacial sediments. It was difficult to distinguish whether these two populations originated from sea ice or icebergs. Therefore, caution should be exercised when using either the > 63 μm or > 250 μm fractions in sediments as a proxy index for iceberg and ice sheet variation in the high Arctic Ocean
Nitrous oxide research progress in polar and sub-polar oceans
Get PDFN2O gas depletes ozone and has a powerful greenhouse effect. Oceans are among the most important N2O sources and have been the subject of extensive studies. Polar oceans are important regions for deep water formation and global-scale thermohaline circulation. Therefore, these water bodies play an important role in the N2O budget, however, these regions were not well studied. This review of previously published studies and data on polar oceans, including both the Arctic Ocean and Southern Ocean, describes the distribution pattern of N2O and possible regulating mechanism of these distribution patterns and shows that the Arctic Ocean and Southern Ocean both represent source and sink regions, suggesting that the source/sink characteristics of the Arctic and Southern oceans and their strengths need further study. Questions related to N2O circulation in polar oceans were proposed, and future work is suggested
Air pollutants and greenhouse gases emission inventory for power plants in the Antarctic
Get PDFEmissions of air pollutants and greenhouse gases into the atmosphere in Antarctica from power plants with diesel generators (the main sources of energy at Antarctic research stations and the main stationary sources of anthropogenic emissions in the Antarctic) were assessed. A bottom-up approach was used to compile an emission inventory for the Antarctic. This involved estimating emissions at various spatial levels by sequentially aggregating estimate emissions from point emission sources. This is the first time this approach has been proposed and used. Emissions of CO2, NOx, particulate matter (PM10), and CO in the modern period were estimated at the research station, geographic region, natural domain, biogeographic region, continent section, and whole continent scales. Yearly emissions are presented here, but the approach allows emissions at different averaging periods to be estimated. This means mean or maximum yearly, monthly, daily, or hourly emissions can be estimated. The estimates could be used to model pollutant transmission and dispersion, assess the impacts of pollutants, and develop emission forecasts for various scenarios
Are Antarctic Specially Protected Areas safe from plastic pollution? a survey of plastic litter at Byers Peninsula, Livingston Island, Antarctica
Get PDFA number of studies have reported in the last decades the presence of plastics in the Southern Ocean, which are liable to reach the coast and accumulate on the Antarctic Continent. Despite this, there are few data on the amount of plastic pollution on Antarctic beaches below 60°S. Here we provide valuable information about the presence of plastic debris in Byers Peninsula, Livingston Island, South Shetland Islands, an Antarctic Specially Protected Area (ASPA) and a hotspot for biodiversity. A total of 129 locations with between 1 and 5 items were recorded among the 3 survey sites on Byers Peninsula. Most of the observed items are likely to derive from fishing and local sources such as tourism and research activities. We discuss the potential impacts of their presence on local fauna and some of the consequences on the Antarctic ecosystem. From this survey of plastic accumulation in an ASPA, we propose the implementation of mitigation strategies, such as systematic monitoring of the abundance and distribution of plastic waste, in order to identify trends in marine debris and control the levels of plastic pollution in the Maritime Antarctic region
Large spread across AeroCom Phase II models in simulating black carbon in melting snow over Arctic sea ice
Get PDFOver two dozen global atmospheric chemistry models contributing to the Aerosol Comparisons between Observations and Models (AeroCom) project were used in this study to drive the Los Alamos sea ice model to simulate the black carbon (BC) concentration in melting snow on Arctic sea ice. Measurements of BC during the melting season show concentrations in the range 2.8–41.6 ng·g−1 (average: 15.3 ng·g−1) in the central Arctic Ocean and Canada Basin. Most results from models contributing to the Phase I project were within the 25th and 75th percentiles of the observations, and the multimodel mean was slightly lower than that of the observations. In contrast, there was larger divergence among the Phase II model simulations and the mean value of BC was overestimated. The multimodel mean bias was −3.1 (−11.2 to +6.7) ng·g−1 for Phase I models and +3.9 (−9.5 to +21.3) ng·g−1 for Phase II models. The differences between the models of the two phases were probably attributable to the updated aerosol scheme in the new contributions, in which removal processes are parameterized by considering the actual dimensions and chemical compositions of the particles. This means the removal mechanism acts in a way that is more selective and leads to more BC particles being transported to the Arctic. In addition, higher spatial resolution could be another important reason for overestimation of BC concentration in snow in Phase II models
Mapping Arctic Research in Iceland
Get PDFThe scope of Arctic research in Iceland has been increasing during the past decade and the amount of grants allocated to Arctic research projects has risen. Mapping Arctic Research in Iceland contains an overview of governance of Arctic policy in Iceland and a profile of Arctic research performers, such as universities, institutes, companies and infrastructure. An analysis of both domestic and international funds supporting Arctic research is the main content of the report. Both domestic and international funds were examined, however the main focus was on the Icelandic Research Fund and EU Horizon 2020. Selected Arctic research projects with Icelandic participation and international platforms that serve Arctic-related issues are described
The fossil record of birds from the James Ross Basin, West Antarctica
Get PDFThe fossil record of birds from Antarctica is concentrated in the James Ross Basin, located in north-east of the Antarctic Peninsula. Birds are here represented by an extensive Paleogene record of penguins (Sphenisciformes) and Cretaceous–Paleogene record of Anseriformes, followed by other groups with a minor representation (Procellariiformes, Falconiformes, and Pelagornithidae), and others previously assigned controversially to “Ratites”, Threskiornithidae, Charadriiformes, Gruiformes, Phoenicopteriformes, and Gaviiformes. We provide a complete update of these records, commenting on the importance of some of these remains for the evolution of the major clades