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143 records – page 1 of 15.

Acoustic signal and noise changes in the Beaufort Sea Pacific Water duct under anticipated future acidification of Arctic Ocean waters.

https://arctichealth.org/en/permalink/ahliterature301804
Source
J Acoust Soc Am. 2017 10; 142(4):1926
Publication Type
Journal Article
Research Support, U.S. Gov't, Non-P.H.S.
Date
10-2017
Author
Timothy F Duda
Author Affiliation
Applied Ocean Physics and Engineering Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA.
Source
J Acoust Soc Am. 2017 10; 142(4):1926
Date
10-2017
Language
English
Publication Type
Journal Article
Research Support, U.S. Gov't, Non-P.H.S.
Keywords
Acoustics
Arctic Regions
Carbon Dioxide - analysis
Environmental monitoring
Hydrogen-Ion Concentration
Models, Theoretical
Pacific Ocean
Seawater - chemistry
Sound Spectrography
Abstract
It is predicted that Arctic Ocean acidity will increase during the next century as a result of carbon dioxide accumulation in the atmosphere and migration into ocean waters. This change has implications for sound transmission because low-pH seawater absorbs less sound than high-pH water. Altered pH will affect sound in the 0.3-10?kHz range if the criterion is met that absorption is the primary cause of attenuation, rather than the alternatives of loss in the ice or seabed. Recent work has exploited sound that meets the criterion, sound trapped in a Beaufort Sea duct composed of Pacific Winter Water underlying Pacific Summer Water. Arctic pH is expected to drop from 8.1 to 7.9 (approximately) over the next 30-50?yr, and effects of this chemical alteration on the intensity levels of this ducted sound, and on noise, are examined here. Sound near 900?Hz is predicted to undergo the greatest change, traveling up to 38% further. At ranges of 100-300?km, sound levels from a source in the duct may increase by 7?dB or more. Noise would also increase, but noise is ducted less efficiently, with the result that 1?kHz noise is predicted to rise approximately 0.5?dB.
PubMed ID
29092580 View in PubMed
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Acute hydrogen peroxide (H2O2) exposure does not cause oxidative stress in late-copepodite stage of Calanus finmarchicus.

https://arctichealth.org/en/permalink/ahliterature286855
Source
J Toxicol Environ Health A. 2017;80(16-18):820-829
Publication Type
Article
Date
2017
Author
Bjørn Henrik Hansen
Anna Hallmann
Dag Altin
Bjørn Munro Jenssen
Tomasz M Ciesielski
Source
J Toxicol Environ Health A. 2017;80(16-18):820-829
Date
2017
Language
English
Publication Type
Article
Keywords
Animals
Copepoda - drug effects
Drug resistance
Food Contamination - prevention & control
Glutathione - metabolism
Hydrogen Peroxide - toxicity
Lethal Dose 50
Malondialdehyde - metabolism
No-Observed-Adverse-Effect Level
Norway
Oxidative Stress - drug effects
Reactive Oxygen Species - metabolism
Seawater - chemistry
Toxicity Tests, Acute
Abstract
Use of hydrogen peroxide (H2O2) for removal of salmon lice in the aquaculture industry has created concern that non-target organisms might be affected during treatment scenarios. The aim of the present study was to examine the potential for H2O2 to produce oxidative stress and reduce survival in one of the most abundant zooplankton species in Norwegian coastal areas, the copepod Calanus finmarchicus. Copepods were subjected to two 96-hr tests: (1) acute toxicity test where mortality was determined and (2) treated copepods were exposed to concentrations below the No Observed Effect Concentration (0.75 mg/L) H2O2 and analyzed for antioxidant enzyme activities, as well as levels of glutathione (GSH) and malondialdehyde (MDA). Compared to available and comparable LC50 values from the literature, our results suggest that C. finmarchicus is highly sensitive to H2O2. However, 96-hr exposure of C. finmarchicus to 0.75 mg H2O2/L did not significantly affect the antioxidant systems even though the concentration is just below the level where mortality is expected. Data suggest that aqueous H2O2 exposure did not cause cellular accumulation with associated oxidative stress, but rather produced acute effects on copepod surface (carapace). Further investigation is required to ensure that aqueous exposure during H2O2 treatment in salmon fish farms does not exert adverse effects on local non-target crustacean species and populations. In particular, studies on copepod developmental stages with a more permeable carapace are warranted.
PubMed ID
28777041 View in PubMed
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Anthropogenic microlitter in the Baltic Sea water column.

https://arctichealth.org/en/permalink/ahliterature294565
Source
Mar Pollut Bull. 2018 Apr; 129(2):918-923
Publication Type
Journal Article
Date
Apr-2018
Author
Andrei Bagaev
Liliya Khatmullina
Irina Chubarenko
Author Affiliation
Shirshov Institute of Oceanology, Russian Academy of Sciences, 36, Nahimovskiy prospekt, Moscow 117997, Russia. Electronic address: andrei.bagaev@atlantic.ocean.ru.
Source
Mar Pollut Bull. 2018 Apr; 129(2):918-923
Date
Apr-2018
Language
English
Publication Type
Journal Article
Keywords
Baltic States
Environmental Monitoring - methods
Particle Size
Plastics - analysis
Poland
Russia
Seawater - chemistry
Waste Products - analysis
Water Pollutants, Chemical - analysis
Abstract
Microlitter (0.5-5mm) concentrations in water column (depth range from 0 to 217.5m) of the main Baltic Proper basins are reported. In total, 95 water samples collected in 6 research cruises in 2015-2016 in the Bornholm, Gdansk, and Gotland basins were analysed. Water from 10- and 30-litre Niskin bathometers was filtered through the 174µm filters, and the filtrate was examined under optical microscope (40×). The bulk mean concentration was 0.40±0.58 items per litre, with fibres making 77% of them. Other types of particles are the paint flakes (19%) and fragments (4%); no microbeads or pellets. The highest concentrations are found in the near-bottom samples from the coastal zone (2.2-2.7 items per litre max) and from near-surface waters (0.5m) in the Bornholm basin (5 samples, 1.6-2.5 items per litre). Distribution of particles over depths, types, and geographical regions is presented.
PubMed ID
29106941 View in PubMed
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Source
Curr Biol. 2010 Mar 23;20(6):R255-6
Publication Type
Article
Date
Mar-23-2010

Arctic amplification is caused by sea-ice loss under increasing CO2.

https://arctichealth.org/en/permalink/ahliterature298890
Source
Nat Commun. 2019 01 10; 10(1):121
Publication Type
Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Date
01-10-2019
Author
Aiguo Dai
Dehai Luo
Mirong Song
Jiping Liu
Author Affiliation
Department of Atmospheric & Environmental Sciences, University at Albany, SUNY, Albany, NY, 12222, USA. adai@albany.edu.
Source
Nat Commun. 2019 01 10; 10(1):121
Date
01-10-2019
Language
English
Publication Type
Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Keywords
Arctic Regions
Carbon Dioxide - metabolism
Climate change
Geography
Global warming
Ice Cover
Seasons
Seawater - chemistry
Solar Energy
Temperature
Abstract
Warming in the Arctic has been much faster than the rest of the world in both observations and model simulations, a phenomenon known as the Arctic amplification (AA) whose cause is still under debate. By analyzing data and model simulations, here we show that large AA occurs only from October to April and only over areas with significant sea-ice loss. AA largely disappears when Arctic sea ice is fixed or melts away. Periods with larger AA are associated with larger sea-ice loss, and models with bigger sea-ice loss produce larger AA. Increased outgoing longwave radiation and heat fluxes from the newly opened waters cause AA, whereas all other processes can only indirectly contribute to AA by melting sea-ice. We conclude that sea-ice loss is necessary for the existence of large AA and that models need to simulate Arctic sea ice realistically in order to correctly simulate Arctic warming under increasing CO2.
PubMed ID
30631051 View in PubMed
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Arctic climatechange and its impacts on the ecology of the North Atlantic.

https://arctichealth.org/en/permalink/ahliterature90693
Source
Ecology. 2008 Nov;89(11 Suppl):S24-38
Publication Type
Article
Date
Nov-2008
Author
Greene Charles H
Pershing Andrew J
Cronin Thomas M
Ceci Nicole
Author Affiliation
Ocean Resources and Ecosystems Program, Snee Hall, Cornell University, Ithaca, New York 14853, USA. chg2@cornell.edu
Source
Ecology. 2008 Nov;89(11 Suppl):S24-38
Date
Nov-2008
Language
English
Publication Type
Article
Keywords
Animals
Atlantic Ocean
Biodiversity
Cold Climate
Conservation of Natural Resources
Ecosystem
Greenhouse Effect
Seawater - chemistry
Sodium Chloride - adverse effects - analysis
Species Specificity
Temperature
Time Factors
Abstract
Arctic climate change from the Paleocene epoch to the present is reconstructed with the objective of assessing its recent and future impacts on the ecology of the North Atlantic. A recurring theme in Earth's paleoclimate record is the importance of the Arctic atmosphere, ocean, and cryosphere in regulating global climate on a variety of spatial and temporal scales. A second recurring theme in this record is the importance of freshwater export from the Arctic in regulating global- to basin-scale ocean circulation patterns and climate. Since the 1970s, historically unprecedented changes have been observed in the Arctic as climate warming has increased precipitation, river discharge, and glacial as well as sea-ice melting. In addition, modal shifts in the atmosphere have altered Arctic Ocean circulation patterns and the export of freshwater into the North Atlantic. The combination of these processes has resulted in variable patterns of freshwater export from the Arctic Ocean and the emergence of salinity anomalies that have periodically freshened waters in the North Atlantic. Since the early 1990s, changes in Arctic Ocean circulation patterns and freshwater export have been associated with two types of ecological responses in the North Atlantic. The first of these responses has been an ongoing series of biogeographic range expansions by boreal plankton, including renewal of the trans-Arctic exchanges of Pacific species with the Atlantic. The second response was a dramatic regime shift in the shelf ecosystems of the Northwest Atlantic that occurred during the early 1990s. This regime shift resulted from freshening and stratification of the shelf waters, which in turn could be linked to changes in the abundances and seasonal cycles of phytoplankton, zooplankton, and higher trophic-level consumer populations. It is predicted that the recently observed ecological responses to Arctic climate change in the North Atlantic will continue into the near future if current trends in sea ice, freshwater export, and surface ocean salinity continue. It is more difficult to predict ecological responses to abrupt climate change in the more distant future as tipping points in the Earth's climate system are exceeded.
PubMed ID
19097482 View in PubMed
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Arctic Ocean: is it a sink or a source of atmospheric mercury?

https://arctichealth.org/en/permalink/ahliterature267311
Source
Environ Sci Technol. 2014;48(3):1707-17
Publication Type
Article
Date
2014
Author
Ashu P Dastoor
Dorothy A Durnford
Source
Environ Sci Technol. 2014;48(3):1707-17
Date
2014
Language
English
Publication Type
Article
Keywords
Air - analysis
Air Pollutants - analysis
Animals
Arctic Regions
Ecosystem
Mercury - analysis
Models, Theoretical
Oceans and Seas
Seasons
Seawater - chemistry
Water Pollutants, Chemical - analysis
Abstract
High levels of mercury in marine mammals threaten the health of Arctic inhabitants. Whether the Arctic Ocean (AO) is a sink or a source of atmospheric mercury is unknown. Given the paucity of observations in the Arctic, models are useful in addressing this question. GEOS-Chem and GRAHM, two complex numerical mercury models, present contrasting pictures of atmospheric mercury input to AO at 45 and 108 Mg yr(-1), respectively, and ocean evasion at 90 and 33 Mg yr(-1), respectively. We provide a comprehensive evaluation of GRAHM simulated atmospheric mercury input to AO using mercury observations in air, precipitation and snowpacks, and an analysis of the discrepancy between the two modeling estimates using observations. We discover two peaks in high-latitude summertime concentrations of atmospheric mercury. We show that the first is caused mainly by snowmelt revolatilization and the second by AO evasion of mercury. Riverine mercury export to AO is estimated at 50 Mg yr(-1) based on measured DOC export and at 15.5-31 Mg yr(-1) based on simulated mercury in meltwater. The range of simulated mercury fluxes to and from AO reflects uncertainties in modeling mercury in the Arctic; comprehensive observations in all compartments of the Arctic ecosystem are needed to close the gap.
PubMed ID
24328426 View in PubMed
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Assessing PCB pollution in the Baltic Sea - An equilibrium partitioning based study.

https://arctichealth.org/en/permalink/ahliterature290670
Source
Chemosphere. 2018 Jan; 191:886-894
Publication Type
Journal Article
Date
Jan-2018
Author
Susann-Cathrin Lang
Philipp Mayer
Andrew Hursthouse
Danijela Kötke
Ines Hand
Detlef Schulz-Bull
Gesine Witt
Author Affiliation
University of Applied Sciences Hamburg, Department of Environmental Engineering, Ulmenliet 20, 21033 Hamburg, Germany; Institute of Biomedical and Environmental Health Research, School of Science & Sport, University of the West of Scotland, Paisley Campus, Paisley PA 1 2BE, United Kingdom. Electronic address: susann-cathrin.lang@agilent.com.
Source
Chemosphere. 2018 Jan; 191:886-894
Date
Jan-2018
Language
English
Publication Type
Journal Article
Keywords
Environmental Monitoring - methods
Environmental pollution - analysis
Finland
Gas Chromatography-Mass Spectrometry
Geologic Sediments - chemistry
Organic Chemicals - analysis
Polychlorinated biphenyls - analysis
Seawater - chemistry
Water Pollutants, Chemical - analysis
Abstract
Sediment cores and bottom water samples from across the Baltic Sea region were analyzed for freely dissolved concentrations (Cfree), total sediment concentrations (CT) and the dissolved aqueous fraction in water of seven indicator PCBs. Ex-situ equilibrium sampling of sediment samples was conducted with polydimethylsiloxane (PDMS) coated glass fibers that were analyzed by automated thermal desorption GC-MS, which yielded PCB concentrations in the fiber coating (CPDMS). Measurements of CPDMS and CT were then applied to determine (i) spatially resolved freely dissolved PCB concentrations; (ii) baseline toxicity potential based on chemical activities (a); (iii) site specific mixture compositions; (iv) diffusion gradients at the sediment water interface and within the sediment cores; and (vi) site specific distribution ratios (KD). The contamination levels were low in the Gulf of Finland and moderate to elevated in the Baltic Proper, with the highest levels observed in the western Baltic Sea. The SPME method has been demonstrated to be an appropriate and sensitive tool for area surveys presenting new opportunities to study the in-situ distribution and thermodynamics of hydrophobic organic chemicals at trace levels in marine environments.
PubMed ID
29107230 View in PubMed
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Bacterial communities of surface mixed layer in the Pacific sector of the western Arctic Ocean during sea-ice melting.

https://arctichealth.org/en/permalink/ahliterature257813
Source
PLoS One. 2014;9(1):e86887
Publication Type
Article
Date
2014
Author
Dukki Han
Ilnam Kang
Ho Kyung Ha
Hyun Cheol Kim
Ok-Sun Kim
Bang Yong Lee
Jang-Cheon Cho
Hor-Gil Hur
Yoo Kyung Lee
Author Affiliation
Korea Polar Research Institute, KIOST, Incheon, Republic of Korea ; School of Environmental Science and Engineering, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea.
Source
PLoS One. 2014;9(1):e86887
Date
2014
Language
English
Publication Type
Article
Keywords
Alphaproteobacteria - classification - genetics - growth & development
Ammonium Compounds - analysis
Arctic Regions
Bacteria - classification - genetics - growth & development
Ecosystem
Flavobacteriaceae - classification - growth & development
Fresh Water - chemistry - microbiology
Gammaproteobacteria - classification - genetics - growth & development
Geography
Ice Cover - chemistry - microbiology
Linear Models
Nitrates - analysis
Nitrogen Dioxide - analysis
Oceans and Seas
Phosphates - analysis
Phylogeny
RNA, Ribosomal, 16S - genetics
Salinity
Seasons
Seawater - chemistry - microbiology
Sequence Analysis, DNA
Silicon Dioxide - analysis
Temperature
Abstract
From July to August 2010, the IBRV ARAON journeyed to the Pacific sector of the Arctic Ocean to monitor bacterial variation in Arctic summer surface-waters, and temperature, salinity, fluorescence, and nutrient concentrations were determined during the ice-melting season. Among the measured physicochemical parameters, we observed a strong negative correlation between temperature and salinity, and consequently hypothesized that the melting ice decreased water salinity. The bacterial community compositions of 15 samples, includicng seawater, sea-ice, and melting pond water, were determined using a pyrosequencing approach and were categorized into three habitats: (1) surface seawater, (2) ice core, and (3) melting pond. Analysis of these samples indicated the presence of local bacterial communities; a deduction that was further corroborated by the discovery of seawater- and ice-specific bacterial phylotypes. In all samples, the Alphaproteobacteria, Flavobacteria, and Gammaproteobacteria taxa composed the majority of the bacterial communities. Among these, Alphaproteobacteria was the most abundant and present in all samples, and its variation differed among the habitats studied. Linear regression analysis suggested that changes in salinity could affect the relative proportion of Alphaproteobacteria in the surface water. In addition, the species-sorting model was applied to evaluate the population dynamics and environmental heterogeneity in the bacterial communities of surface mixed layer in the Arctic Ocean during sea-ice melting.
Notes
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PubMed ID
24497990 View in PubMed
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Bacterial responses to fluctuations and extremes in temperature and brine salinity at the surface of Arctic winter sea ice.

https://arctichealth.org/en/permalink/ahliterature257926
Source
FEMS Microbiol Ecol. 2014 Aug;89(2):476-89
Publication Type
Article
Date
Aug-2014
Author
Marcela Ewert
Jody W Deming
Author Affiliation
School of Oceanography, University of Washington, Seattle, WA, USA.
Source
FEMS Microbiol Ecol. 2014 Aug;89(2):476-89
Date
Aug-2014
Language
English
Publication Type
Article
Keywords
Alaska
Arctic Regions
Cold Temperature
Freezing
Gammaproteobacteria - physiology
Ice Cover - microbiology
Salinity
Salt-Tolerance
Seasons
Seawater - chemistry - microbiology
Snow - microbiology
Abstract
Wintertime measurements near Barrow, Alaska, showed that bacteria near the surface of first-year sea ice and in overlying saline snow experience more extreme temperatures and salinities, and wider fluctuations in both parameters, than bacteria deeper in the ice. To examine impacts of such conditions on bacterial survival, two Arctic isolates with different environmental tolerances were subjected to winter-freezing conditions, with and without the presence of organic solutes involved in osmoprotection: proline, choline, or glycine betaine. Obligate psychrophile Colwellia psychrerythraea strain 34H suffered cell losses under all treatments, with maximal loss after 15-day exposure to temperatures fluctuating between -7 and -25 °C. Osmoprotectants significantly reduced the losses, implying that salinity rather than temperature extremes presents the greater stress for this organism. In contrast, psychrotolerant Psychrobacter sp. strain 7E underwent miniaturization and fragmentation under both fluctuating and stable-freezing conditions, with cell numbers increasing in most cases, implying a different survival strategy that may include enhanced dispersal. Thus, the composition and abundance of the bacterial community that survives in winter sea ice may depend on the extent to which overlying snow buffers against extreme temperature and salinity conditions and on the availability of solutes that mitigate osmotic shock, especially during melting.
PubMed ID
24903191 View in PubMed
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143 records – page 1 of 15.