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1.
Environ Monit Assess ; 192(11): 670, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33009644

RESUMO

Antarctica is considered as one of the most pristine areas on Earth. However, increasing intensity of human presence on the sixth continent (scientific operations, functioning of the numerous scientific stations, tourism activities) makes it crucial to investigate the level of environmental pollution within the vulnerable ecosystem of Antarctica. Soils play a significant role in processes of accumulation, mobilization, redistribution of chemical elements within landscapes, and ecosystems. The aim of this work was to analyze the levels of 17 polycyclic aromatic hydrocarbons and eight trace elements in soils of King George and Ardley islands, Western Antarctica. Moreover, our work was aimed to determine the trends and reasons of anthropogenic pollution of Antarctic soils and characterization of accumulation levels of trace elements and PAHs. Results showed the predominance of light PAHs in all studied sites. The content of benzo(a)pyrene does not exceed the threshold concentration (adopted by different national environmental legislation systems). At the same time, the content of benzo(a)pyrene, which is a marker of anthropogenic contamination, is relatively low or equal to 0 in soils of reference landscapes. Cu and Zn were found as most abundant elements in all studied soils. The highest lead concentration content has been described in soil from Bellingshausen station. In general term, obtained Igeo values for trace elements in all samples were under or slightly above the 0 level, indicating low to moderate pollution of the studied soils. This study also contributes new data on trace element accumulation in soils strongly influenced by ornithogenic factor. Principal component analysis allowed to estimate the probable sources of specific trace metals and their relationship with soil variables. Ornithogenic factor has been also revealed as a driver for some trace element accumulation especially in breeding penguin colonies. High contents of organic matter in ornithogenic habitats could increase trace metal mobility, environmental risks for surrounding terrestrial environments should be considered.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes do Solo/análise , Oligoelementos/análise , Regiões Antárticas , Ecossistema , Monitoramento Ambiental , Humanos , Ilhas , Solo
2.
Mar Environ Res ; 160: 105025, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32907735

RESUMO

Disturbance is a key factor in most natural environments and, globally, disturbance regimes are changing, driven by increased anthropogenic influences, including climate change. There is, however, still a lack of understanding about how disturbance interacts with species dispersal capacity to shape marine assemblage structure. We examined the impact of ice scour disturbance history (2009-2016) on the nearshore seafloor in a highly disturbed region of the Western Antarctic Peninsula by contrasting the response of two groups with different dispersal capacities: one consisting of high-dispersal species (mobile with pelagic larvae) and one of low-dispersal species (sessile with benthic larvae). Piecewise Structural Equation Models were constructed to test multi-factorial predictions of the underlying mechanisms, based on hypothesised responses to disturbance for the two groups. At least two or three disturbance factors, acting at different spatial scales, drove assemblage composition. A comparison between both high- and low-dispersal models demonstrated that these mechanisms are dispersal dependent. Disturbance should not be treated as a single metric, but should incorporate remote and direct disturbance events with consideration of taxa-dispersal and disturbance legacy. These modelling approaches can provide insights into how disturbance shapes assemblages in other disturbance regimes, such as fire-prone forests and trawl fisheries.


Assuntos
Mudança Climática , Meio Ambiente , Larva , Animais , Regiões Antárticas , Oceanos e Mares , Movimentos da Água
3.
Mar Pollut Bull ; 159: 111471, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32892914

RESUMO

Plastic ingestion by seabirds is an efficient way to monitor marine plastics. We report temporal variation in the characteristics of marine litter regurgitated by albatrosses and giant petrels on sub-Antarctic Marion Island between 1996 and 2018. Both fishery and other litter peaked during the height of the Patagonian toothfish fishery around the island (1997-1999). Comparing the two subsequent decades of reduced fishing effort (1999-2008 and 2009-2018), fishing litter decreased while other litter increased across all species. Litter increased most in grey-headed albatrosses, followed by giant petrels and wandering albatrosses. Similar ranked responses were found in the same species at South Georgia, but non-fishery-related litter has increased faster in the Indian Ocean than the southwest Atlantic, indicating regional changes in litter growth rates. These seabirds' regurgitations provide an easy, non-invasive way to track changes in oceanic litter in a remote area that is otherwise difficult to monitor.


Assuntos
Monitoramento Ambiental , Plásticos , Animais , Regiões Antárticas , Aves , Oceano Índico , Ilhas , Resíduos
4.
Sci Total Environ ; 740: 140379, 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-32927555

RESUMO

The Antarctic Peninsula is one of the regions to be most affected by increase in sea surface temperatures (SSTs) mediated by Global Climate Change; indeed, most negative predictions imply an up to 6 °C increment by the end of the XXI century. Temperature is one of the most important factors mediating diversity and distribution of macroalgae, although there is still no consensus as to the likely effects of higher SSTs, especially for polar seaweeds. Some available information suggests that potential strategies to withstand future increases in SSTs will be founded upon the glutathione-ascorbate cycle and the induction of chaperone-functioning heat shock proteins (HSPs); however, their eventual role, even for general stress responses, is unclear. The intertidal green, brown and red macroalgae species Monostroma hariotii, Adenocystis utricularis and Pyropia endiviifolia, respectively, from King George Island, Antarctic Peninsula, were exposed to 2 °C (control) and 8 °C (climate change scenario) for up to 5 days (d). Photosynthetic activity (αETR and ETRmax, and EkETR), photoinhibition (Fv/Fm) and photoprotection processes (αNPQ, NPQmax, and EkNPQ) provided no evidence of negative ecophysiological effects. There were moderate increases in H2O2 production and levels of lipid peroxidation with temperature, results supported by stable levels of total glutathione and ascorbate pools, with mostly higher levels of reduced ascorbate and glutathione than oxidized forms in all species. Transcripts of P. endiviifolia indicated a general upregulation of all antioxidant enzymes and HSPs genes studied under warmer temperature, although with different levels of activation with time. This pioneering investigation exploring different levels of biological organization, suggested that Antarctic intertidal macroalgae may be able to withstand future rise in SSTs, probably slightly altering their latitudinal distribution and/or range of thermal tolerance, by exhibiting robust glutathione-ascorbate production and recycling, as well as the induction of associated antioxidant enzymatic machinery and the syntheses of HSPs.


Assuntos
Alga Marinha , Regiões Antárticas , Mudança Climática , Peróxido de Hidrogênio , Oceanos e Mares , Temperatura
6.
Proc Biol Sci ; 287(1933): 20201544, 2020 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-32811318

RESUMO

Changes in the foraging environment and at-sea distribution of southern elephant seals from Kerguelen Islands were investigated over a decade (2004-2018) using tracking, weaning mass, and blood δ13C values. Females showed either a sub-Antarctic or an Antarctic foraging strategy, and no significant shift in their at-sea distribution was detected between 2004 and 2017. The proportion of females foraging in sub-Antarctic versus Antarctic habitats did not change over the 2006-2018 period. Pup weaning mass varied according to the foraging habitat of their mothers. The weaning mass of sub-Antarctic foraging mothers' pups decreased by 11.7 kg over the study period, but they were on average 5.8 kg heavier than pups from Antarctic foraging mothers. Pup blood δ13C values decreased by 1.1‰ over the study period regardless of their sex and the presumed foraging habitat of their mothers. Together, these results suggest an ecological change is occurring within the Indian sector of the Southern Ocean with possible consequences on the foraging performance of southern elephant seals. We hypothesize that this shift in δ13C is related to a change in primary production and/or in the composition of phytoplankton communities, but this requires further multidisciplinary investigations.


Assuntos
Focas Verdadeiras/sangue , Desmame , Animais , Regiões Antárticas , Isótopos de Carbono/sangue , Feminino , Masculino
7.
Mar Pollut Bull ; 158: 111447, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32753223

RESUMO

As the role of mercury is poorly known in Southern Ocean biota, the total mercury (T-Hg) concentrations were evaluated in upper/lower beaks, digestive gland, gills and mantle muscle of Adelieledone polymorpha and Pareledone turqueti, two of the most abundant octopod species around South Georgia. Beaks had the lowest T-Hg concentrations (A. polymorpha: [T-Hg]Upper = 27.2 ± 12.9 ng∙g-1 and [T-Hg]Lower = 27.5 ± 20.0 ng∙g-1; P. turqueti: [T-Hg]Upper = 34.6 ± 13.9 ng∙g-1 and [T-Hg]Lower = 56.8 ± 42.0 ng∙g-1), followed by gills and muscle. The highest values were recorded in the digestive gland (A. polymorpha: 251.6 ± 69.7 ng∙g-1; P. turqueti: 347.0 ± 177.0 ng∙g-1). Significant relationships were found between the concentrations of T-Hg in the beaks and muscle of A. polymorpha (T-Hg in muscle is 10 times higher than in beaks). This study shows that beaks can be used as proxy for T-Hg in muscle for some octopod species, and a helpful tool for estimating total Hg body burden from beaks.


Assuntos
Mercúrio/análise , Poluentes Químicos da Água/análise , Animais , Regiões Antárticas , Bico/química , Monitoramento Ambiental , Ilhas
8.
Sci Total Environ ; 737: 140210, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32783841

RESUMO

Microplastics are present in almost all seas and oceans, including the Southern Ocean. To the south of the Antarctic Polar Front, microplastics are present mainly west to the Antarctic Peninsula, but information is scarce about their impact on the pelagic food web. Here, we analysed 42 scats of male Antarctic fur seals (Arctocephalus gazella) collected in late summer at Deception Island (South Shetland Islands), which allowed us to assess the presence of microplastics in the pelagic food web of the Bransfield Strait (Western Antarctica). Furthermore, we analysed the hard remains of prey in the scats to characterize the diet of fur seals. Hard remains recovered from the scats revealed that male Antarctic fur seals foraged on krill and myctophid fishes during late summer. Fourier-transform infrared spectroscopy (FT-IR) revealed that none of the seven fragments and three fibres recovered from their scats were microplastics, but rather were silicate minerals and chitin. These results suggest that the levels of microplastic pollution in the pelagic food web of the Bransfield Strait are extremely low.


Assuntos
Otárias , Animais , Regiões Antárticas , Atividades Humanas , Masculino , Microplásticos , Oceanos e Mares , Plásticos , Espectroscopia de Infravermelho com Transformada de Fourier
9.
Sci Total Environ ; 737: 140258, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32783853

RESUMO

In recent decades, the relationships between species distributional shifts and climate change have been investigated at various geographic scales, yet there is still a gap in understanding the impacts of climate change on marine commercial fish species surrounding the Antarctic Peninsula. The dynamic bioclimate envelope model (DBEM) is a mechanistic model that encompass species distribution model and population dynamic model approaches to project the spatiotemporal change of marine commercial fish species driven by various climate change scenarios in the Southern Ocean. This paper focuses on the spatiotemporal changes of marine commercial fish species surrounding the Antarctic Peninsula under a high emissions scenario (RCP8.5) and a low emissions scenario (RCP2.6) from 1970 to 2060 following three different Earth System Models (ESMs), namely, the GFDL-ESM 2G, IPSL-CM5A-MR and MPI-ESM-MR. Results reveal that: i) The general latitudinal gradient patterns in species richness shifts poleward associated with a global abundance decrease ii) The Spp. richness in Eastern Antarctic Peninsula (EAP) is higher than in the Western Antarctic Peninsula (WAP) at the same latitude (>65°S latitude). iii) The reasons are that the krill-dependent predators in WAP could face a higher risk of depletion than that in EAP due to ocean warming and anthropogenic activities.


Assuntos
Mudança Climática , Euphausiacea , Animais , Regiões Antárticas , Ecossistema , Peixes
10.
Extremophiles ; 24(5): 797-807, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32789694

RESUMO

We recovered 85 fungal isolates from the acid sulphate soils in chronosequence under para-periglacial conditions in King George Island, Antarctica. Thirty-two taxa belonging to the phylum Ascomycota, Basidiomycota and Mortierellomycota were identified. Mortierella amoeboidea, Mortierella sp. 2, Mortierella sp. 3, Penicillium sp. 2 and Penicillium sp. 3 dominated the sulphite soils. Despite the multi-extreme physic-chemical conditions of the sulphate soils (low pH, variable content of macro and micronutrients and organic matter), the fungal assemblages exhibited moderate diversity indices, which ranged according to the degree of soil development. Soils with more weathered and, consequently, with highest values of organic carbon shelter the most diverse fungal assemblages, which can be associated with the occurrence of sulphurisation and sulphide oxidation. Different taxa of Mortierella and Penicillium displayed broad pH (3-9) and temperature (5-35 °C) plasticity. The multi-extreme sulphite soils of Antarctica revealed the presence of moderate fungal diversity comprising cold cosmopolitan and psychrophilic endemic taxa. Among these, Mortierella and Penicillium, known to survive in extreme conditions such as low temperature and available organic matter, low pH and high concentrations of metals, might represent interesting techniques to be used in biotechnological processes such as bioleaching in metallurgy and phosphate solubilisation in agriculture.


Assuntos
Biodiversidade , Fungos , Solo , Regiões Antárticas , Ilhas , Microbiologia do Solo , Sulfatos
11.
Environ Monit Assess ; 192(9): 559, 2020 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-32747987

RESUMO

This article aims to analyze the dynamics of freezing and thawing of Antarctic lakes located in ice-free areas on Nelson Island and Fildes Peninsula, where response to changes in air temperature and precipitation rates occur rapidly, during the period from July 2016 to December 2018. In these places, which are difficult to access, remote sensing is an important alternative, especially considering the use of active remote sensors such as the Synthetic Aperture Radar (SAR), which has less restriction regarding the presence of clouds over the study area. Three backscatter thresholds were defined (σ) for the identification of the physical state of the water of the lakes of the study region, applied in Sentinel 1A SAR (S1A) images under Horizontal Horizontal (HH) polarization and Interferometric Wide (IW) imaging mode. These images, along with the air temperature data obtained by the Interim Re-Analysis (ERA-Interim) atmospheric reanalysis model, provided the evidence for the interpretation of the freezing and thawing periods of the lakes. The thresholds applied for the definition of the physical state of the lake water were greater than - 14 dB for frozen water, between - 14 and - 17 dB for the surface, with up to 60% of their frozen area, and less than - 17 dB for open water. The temporal analysis revealed that the lakes start to thaw in October, become completely thawed in February, and freeze again in March. Nevertheless, it can be said that the S1A satellite allows a satisfactory identification of the liquid and solid phases of the water in the lakes of the study region.


Assuntos
Lagos , Radar , Regiões Antárticas , Monitoramento Ambiental , Congelamento , Ilhas
12.
Proc Biol Sci ; 287(1931): 20201134, 2020 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-32693727

RESUMO

Antarctica is estimated to contain as much as a quarter of earth's marine methane, however we have not discovered an active Antarctic methane seep limiting our understanding of the methane cycle. In 2011, an expansive (70 m × 1 m) microbial mat formed at 10 m water depth in the Ross Sea, Antarctica which we identify here to be a high latitude hydrogen sulfide and methane seep. Through 16S rRNA gene analysis on samples collected 1 year and 5 years after the methane seep formed, we identify the taxa involved in the Antarctic methane cycle and quantify the response rate of the microbial community to a novel input of methane. One year after the seep formed, ANaerobic MEthane oxidizing archaea (ANME), the dominant sink of methane globally, were absent. Five years later, ANME were found to make up to 4% of the microbial community, however the dominant member of this group observed (ANME-1) were unexpected considering the cold temperature (-1.8°C) and high sulfate concentrations (greater than 24 mM) present at this site. Additionally, the microbial community had not yet formed a sufficient filter to mitigate the release of methane from the sediment; methane flux from the sediment was still significant at 3.1 mmol CH4 m-2 d-1. We hypothesize that this 5 year time point represents an early successional stage of the microbiota in response to methane input. This study provides the first report of the evolution of a seep system from a non-seep environment, and reveals that the rate of microbial succession may have an unrealized impact on greenhouse gas emission from marine methane reservoirs.


Assuntos
Metano , Regiões Antárticas , Archaea/fisiologia , Temperatura Baixa , Fenômenos Ecológicos e Ambientais , Sedimentos Geológicos , Microbiota , Filogenia , Água do Mar , Análise de Sequência de DNA , Sulfatos
13.
Mar Pollut Bull ; 157: 111351, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32658703

RESUMO

During the last decades plastic pollution has become a common issue in marine environments. Studies on seabirds have focused on species that ingest plastics mistaken for prey or indirectly through their preferred prey or, on how foraging strategy influences this behaviour. We evaluated plastic ingestion in relation to the proximity of nests to areas with different anthropogenic pressure, breeding status and breeding stage. We analyzed regurgitated pellets (n = 1001) from a seabird, the Brown Skua (Stercorarius antarcticus lonnbergi) at Esperanza/Hope Bay, Antarctic Peninsula. Plastics were found in 9% of pellets, only in breeders from an area with high antropogenic activity. The prevalence of plastic increased during the brooding of chicks stage, when skuas expand their feeding niche. Our results support previous work which demonstrated that seabirds with wider feeding niche show higher loads of plastics. Altogether, this provides insights into the dynamics of plastic transfer within the environment.


Assuntos
Charadriiformes , Plásticos , Animais , Regiões Antárticas , Cruzamento , Monitoramento Ambiental
14.
Mar Environ Res ; 159: 104976, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32662429

RESUMO

The Chatham Rise, one of the highest offshore-primary production regions in New Zealand waters, hosts a great abundance and diversity of deep-sea cephalopods including the greater hooked squid, Moroteuthopsis ingens. Stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) and trace element concentrations (Ag, As, Cd, Co, Cr, Cu, Fe, Hg, Ni, Pb, Se, V, and Zn) were assessed in female and male specimens of different size classes (89-563 mm mantle length). Values of δ13C and δ15N were overall higher in females and δ13C was further influenced by size and sex. Both muscular mantle (the largest fraction of the total body mass) and digestive gland (the known main storage organ for Ag, Cd, Cu and Zn in many cephalopods) tissues were analysed. Higher levels of Cd were observed in males than in females. A positive effect was found between size and Hg concentrations, which could be related to the ontogenetic descent of larger specimens into deeper waters, where they are exposed to higher Hg concentrations, and/or dietary shifts toward Hg-enriched prey with increasing size. This study provides trace element data for this abundant and ecologically important species, and further reveals higher trace element concentrations (especially Hg) in M. ingens from the Chatham Rise, compared to specimens from the sub-Antarctic zone.


Assuntos
Decapodiformes , Oligoelementos , Poluentes Químicos da Água , Animais , Regiões Antárticas , Monitoramento Ambiental , Feminino , Isótopos , Masculino , Nova Zelândia , Caracteres Sexuais
15.
Mar Environ Res ; 159: 104991, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32662431

RESUMO

Glacier meltdown is a major environmental response to climate change in the West Antarctic Peninsula. Yet, the consequences of this process for local biodiversity are still not well understood. Here, we analyse the diversity and structure of a species-rich marine subtidal macrobenthic community (consumers and primary producers) across two abiotic environmental gradients defined by the distance from a glacier (several km) and depth (between 5 and 20 m depth) in Fildes Bay, King George Island. The analysis of spatially extensive records of seawater turbidity, high-frequency temperature and salinity data, and suction dredge samples of macrobenthic organisms revealed non-linear and functional group-dependent associations between biodiversity, glacier influence, and depth. Turbidity peaked in shallow waters and in the nearby of the glacier. Temperature and salinity, on the other hand, slightly decreased in the proximity of the glacier relative to reference sites. According to the spatial pattern in turbidity, species richness of consumers was lowest in shallow waters and near to the glacier. Also, Shannon's diversity of consumers significantly decreased in the nearby of glacier across depths. Moreover, the spatial variation in community structure of consumers and primary producers depended on both glacier distance and depth. These results suggest that glacier melting can have significant effects on diversity and community structure. Therefore, the accelerated glacier meltdown may have major consequences for the biodiversity in this ecosystem.


Assuntos
Biodiversidade , Ecossistema , Camada de Gelo , Animais , Regiões Antárticas , Ilhas
16.
PLoS One ; 15(7): e0236023, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32697794

RESUMO

The early peopling of the Americas has been one of the most hotly contested topics in American anthropology and a research issue that draws archaeologists into a multidisciplinary debate. In South America, although the background data on this issue has increased exponentially in recent decades, the core questions related to the temporal and spatial patterns of the colonization process remain open. In this paper we tackle these questions in the light of the quantitative analysis of a screened radiocarbon database of more than 1600 early dates. We explore the frequency of radiocarbon dates as proxies for assessing population growth; and define a reliable and statistically well supported lower chronological bound (not to the exact date) for the earliest human arrival. Our results suggest that the earliest chronological threshold for the peopling of South America should be between 16,600 and 15,100, with a mean estimated date ~ 15,500 cal BP (post Last Glacial Maximum). Population would have grown until the end of Antarctic Cold Reversal stadial ~12,500 cal BP at the time of the main extinctions of megafauna-, when the increase rate slows, probably as a result of the changes that occurred in the trophic niche of humans.


Assuntos
Radioisótopos de Carbono/análise , Migração Humana , Crescimento Demográfico , Datação Radiométrica/métodos , Regiões Antárticas , Humanos , América do Sul
17.
Food Chem ; 333: 127448, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32663748

RESUMO

Antarctic krill oil (AKO) is an emerging dietary supplement containing metal ions that influence oil oxidation. Thus, this study focuses on the effect and mechanism of metal ions on phospholipid oxidation in AKO. Firstly, AKO containing Mg2+, Mn2+, Cu2+, Fe2+ and Fe3+ (200 µmol/kg) were prepared separately and incubated at 60 °C for 6 days. Peroxide value (POV) and malondialdehyde (MDA) content showed that Fe3+ exhibited the most effective prooxidative activity, with the prooxidative activity of Fe2(SO4)3 (water-soluble) being stronger than that of ferric oleate (FeOl, fat-soluble). In addition, phosphatidylethanolamine (PE) oxidation degree (more than 90%) was considerably greater than phosphatidylcholine (PC) oxidation degree (about 15%) in AKO. Differences in the structure of head group hindered chelation of PC with metal ions than PE due to electrostatic repulsion and steric hindrance. Therefore, PC significantly inhibited, while PE promoted, the oxidation of polyunsaturated triacylglycerol (TAG), like fish oil (p < 0.01).


Assuntos
Euphausiacea/química , Metais/química , Óleos/química , Fosfolipídeos/química , Animais , Regiões Antárticas , Cátions/química , Suplementos Nutricionais , Malondialdeído/química , Oxirredução , Fosfatidilcolinas/química , Fosfatidiletanolaminas/química , Triglicerídeos/química
18.
J Travel Med ; 27(6)2020 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-32657340

RESUMO

BACKGROUND: Before the impact of the coronavirus disease 2019 pandemic, cruise travel had experienced exponential growth in the preceding decade. Travel medicine practitioners were increasingly called upon to provide pre-cruise travel advice and medical clearance. Demand for these services will return at some time in the future. METHODS: The clinical conditions seen in those presenting for care on six small-vessel scientific cruises to Antarctica were analysed. RESULTS: Personnel presented on 196 occasions resulting in 257 consultations (when initial plus all follow-up consultations were included). Personnel presented with a clinical condition at a rate of 17.9 per 1000 person-days at sea. The total consultation rate was 23.5 per 1000 person-days at sea. Injury accounted for 24% of all presentations at a rate of 4.3 per 1000 person-days at sea. Dermatological, soft tissue and musculoskeletal, general malaise and motion sickness were the four most common presentations. CONCLUSIONS: Pre-cruise advice for travellers planning small-vessel cruises to polar regions needs to include skin care, prevention and management of sea sickness and how to reduce the risk of injury. Those providing medical care on such cruises should be prepared to manage a wide range of clinical presentations.


Assuntos
Encaminhamento e Consulta/estatística & dados numéricos , Navios , Medicina de Viagem/estatística & dados numéricos , Regiões Antárticas , Humanos , Infecções/epidemiologia , Infecções/terapia , Enjoo devido ao Movimento/epidemiologia , Enjoo devido ao Movimento/terapia , Dermatopatias/epidemiologia , Dermatopatias/terapia , Ferimentos e Lesões/epidemiologia , Ferimentos e Lesões/terapia
19.
Nature ; 583(7817): 567-571, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32669711

RESUMO

Recent assessments of Earth's dwindling wilderness have emphasized that Antarctica is a crucial wilderness in need of protection1,2. Yet human impacts on the continent are widespread3-5, the extent of its wilderness unquantified2 and the importance thereof for biodiversity conservation unknown. Here we assemble a comprehensive record of human activity (approximately 2.7 million records, spanning 200 years) and use it to quantify the extent of Antarctica's wilderness and its representation of biodiversity. We show that 99.6% of the continent's area can still be considered wilderness, but this area captures few biodiversity features. Pristine areas, free from human interference, cover a much smaller area (less than 32% of Antarctica) and are declining as human activity escalates6. Urgent expansion of Antarctica's network of specially protected areas7 can both reverse this trend and secure the continent's biodiversity8-10.


Assuntos
Biodiversidade , Meio Selvagem , Animais , Regiões Antárticas , Conservação dos Recursos Naturais , História do Século XIX , História do Século XX , História do Século XXI , Atividades Humanas/história
20.
Chemosphere ; 260: 127634, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32683032

RESUMO

Endosulfan I, II, and sulfate were detected in the atmosphere and surface seawater on a global scale during three Chinese National Arctic-Antarctic Research Expeditions in 2016 and 2017. Concentrations of the three species displayed seasonal variations in seawater in the Northern Hemisphere but remained steadily low on Antarctic coasts. Endosulfan sulfate was predominant in the Northern Hemisphere, whereas isomer I was more abundant in the Southern Hemisphere. Endosulfan was detected in the atmosphere over the western Pacific Ocean but rarely in the central Arctic and North Atlantic oceans. Its concentration in seawater increased with increasing latitude in the Southern Ocean. Although fugacity ratios indicate a strong potential for deposition of endosulfan, air-seawater exchange may be slow, as suggested by the large differences between atmospheric and seawater concentrations. Ocean current endosulfan loads varied markedly between seasons. Three-day backward trajectories indicate that Northeast Asia is the major source of atmospheric endosulfan in the western Pacific Ocean, whereas the central Arctic and North Atlantic oceans are affected more by local air masses.


Assuntos
Endossulfano/análise , Monitoramento Ambiental , Poluentes Ambientais/análise , Regiões Antárticas , Regiões Árticas , Oceano Atlântico , Atmosfera/química , Endossulfano/análogos & derivados , Oceano Pacífico , Estações do Ano , Água do Mar/química
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