Arctic Ocean: projects/activities

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Directory entires that have specified Arctic Ocean as one of the geographic regions for the project/activity and are included in the AMAP, ENVINET, SAON and SEARCH directories. Note that the list of regions is not hierarchical, and there is no relation between regions (e.g. a record tagged with Nunavut may not be tagged with Canada). To see the full list of regions, see the regions list. To browse the catalog based on the originating country (leady party), see the list of countries.

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Displaying: 1 - 20 of 27 Next
1. Restoration of the salmon stock in the Tuloma river system

The possibility of restoring the salmon stocks in the Tuloma system is assessed by collecting background information on the river system: present fish fauna, habitat quality, migratory routes etc. Planning the restoration including technical and management aspects is under way.

Biological effects Biology Populations Hydrography Catchment studies Fish Indigenous people Acidification Spatial trends Modelling Biodiversity Arctic Reproduction Diet Temporal trends Ecosystems
2. Monitoring of the Atlantic salmon stocks of the Teno (Tana) and Näätämö (Neidenelva) river systems, northernmost Fennoscandia.

Monitoring of the salmon stocksof the Teno and Näätämö river systems is based on long term data collection on juvenile salmon production, biological characteristics of the spawning stock, origin of salmon (wild/reared) and statistics on fishery and catches. Information on other fish species than salmon is also available.

Biological effects Biology Populations Hydrography Catchment studies Fish Indigenous people Acidification Spatial trends Modelling Biodiversity Arctic Reproduction Diet Temporal trends Ecosystems
3. ATMospheric Fluxes from Arctic Snow Surfaces - ATMS

The central objectives of the proposed ATMAS project are:  to quantify the photo-chemically triggered NOx and HONO re-emission fluxes from permanently and seasonally snow-covered surfaces in the Arctic near Ny-Ålesund,  to quantify the sources of NO3 in these snow-covered surfaces. In detail, the following scientific objectives of ATMAS can be distinguished: 1. to quantify atmospheric gradient fluxes of HNO3, HONO, particulate nitrogen compounds, and nitrogen in precipitation (snow and rain) above snow surfaces; 2. to quantify the emission of NOx and HONO from the snow pack as atmospheric gradient fluxes 3. to formulate an influx-outflow relationship that can be used in dependence on the snow type for (photo-)chemical atmospheric process models. The results of this research may be expanded to a regional (European) or global scale, to suggest how the NOx and HONO re-emission process and its consequences can be included into regional emission, dispersion and deposition models used in Europe.

Atmospheric processes Ozone gaseous ammonia nitrogen bio-geochemical cycle Pollution sources Climate change tropospheric boundary layer nitrogen oxides Ice Emissions SNOW and SNOWPACK Arctic Data management photochemical production Atmosphere Human health
4. Long-term effects of offshore discharges on cold water zooplankton: establishing a test system for chronic exposure to offshore discharges

During the last decade the concern regarding environmental effects of the offshore industry has shifted from effects of drilling discharges on benthic communities, towards a stronger focus on the water column and effects on the pelagic ecosystem. At the same time, oil and gas development is expanding in the Norwegian and Russian sectors of the Barents Sea. In this regard, a project has been initiated to look at responses of especially Calanus spp. and other copepod species to long-term, sublethal exposure to selected offshore discharges and discharge components, as well as accidental oil spills. Calanus spp. is ecologically the most important zooplankton species along the Norwegian shelf and in the Barents Sea. A laboratory based facility for culture through several generations is being developed through this project. In addition, the impact of oil compounds on the cold-water and arctic Calanus species-complex will be examined by carrying out a series of laboratory (some at Ny Ålesund) and ship based experiments. The response parameters will include both behavioral (feeding, mate finding, avoidance) and physiological (mortality, egg production, development rates, oxygen consumption and assimilation efficiency) parameters. The ultimate outcome of this research is expected to be a supporting instrument for ecological risk assessment of offshore discharges, which is highly relevant both to the North Sea, the mid-Norway shelf and the Barents Sea.

Pathways Biological effects Biology PAHs Pollution sources Environmental management Contaminant transport Petroleum hydrocarbons Exposure Arctic Oil and Gas
5. Hydrology and water currents in the inner part of Kongsfjord in front of Kongsbreen Glacier

The aim of this project is to study the physical oceanography of the sea in the area where Kongsbreen glacier get in touch with the sea in the inner part of Kongsfjord. In particular the project aims:  to characterise temperature and salinity of water masses in the inner part of Kongsfjord close to Kongsbreen Glacier  to characterise major fresh water outflow from Kongsbreen glaciers to the sea in the inner part of the fiord  to collect time series if seawater currents in-out from the inner part, temperature and salinity patterns for one year from summer 2001 to summer 2002.  to collect a one year time series of sea level changes by an automatic self recording depth gauges deployed close to the base.

Glaciers Kongsfjord Hydrography Water currents Hydrology sea level change salinity Sea ice Climate change Ice Oceanography Arctic temperature Ocean currents Kongsbreen
6. Role of organic and inorganic particles in the mobility of radionuclides in the Kongsfjord-Krossfjord system (MORAK)

The aims of the project are: - to evaluate the fluxes of radionuclides in the water column and their accumulation in the sediment, on a short-time scale; - to determine the C/N and delta13C-delta15N ratios in suspended and sedimentary matter, and test their use as tracers of origin, composition and transformation pathways of organic particles. The selected study area is the Kongsfjord-Krossfjord system, Svalbard, considered as representative test-site for studying processes occurring in Arctic fjords. The focus of the project will be on the processes occurring at the glacier-sea interface, where enhanced lithogenic and biogenic particle fluxes are reported in summer. Specific methods will be used to trace the particle sources. The rate of accumulation-resuspension processes will also be investigated from the inner fjord to the outer continental shelf.

Glaciers Hydrography Climate Sea ice Contaminant transport Radionuclides Oceanography Arctic Sediments Ocean currents
7. Relative importance of different sources of particulate matter in the Kongsfjorden environment

The general objective of this research concerns the quantitative and qualitative study of particulate matter retained in natural (sea-ice and sediment) and artificial (sediment traps) traps in order to determine the main origin (autochtonous and allochtonous) and the relative importance of different fractions of particulate matter and to follow their fate in the environment. To quantify the autochtonous origin of particulate matter, primary production, nutrient uptake, biomass distribution, phytoplankton community structure and fluxes in the first levels of the trophic chain will be investigated. Studies will be conducted in the sea-ice environment and in the water column and compared to the particle fluxes measured both in the water, using sediment traps and in the sediment, by radiometric chronology, in order to estimate the different contribution of these habitats to carbon export to the bottom. The zooplankton will be identified and counted and primary production, nutrient uptake and phytoplankton dynamics will be related to hydrological structure and nutrient availability in the environment. The Kongsfjord results particularly suitable for the main objective of this research as it is influenced by important inputs of both atmospheric (eolic and meteroric) and glacial origin and is characterised by a complex hydrological situation which may promote autochtonous productive processes, thus determining important particulate fluxes.

athmospheric carbon dioxide Biological effects Biology Arctic haze Hydrography inorganic and organic nutrients particulate Sea ice Ice Oceanography Biodiversity Arctic Ice cores Data management Atmosphere Ocean currents phytoplankton sediment radiometric chronology zooplankton
8. Ice ridging information for decision making in shipping operations

IRIS brings together several EU partners to investigate methods to estimate sea ice ridging severity from satellite imagery and assess the impact of these ridges on icebreaker transit times, particularly in the Baltic Sea. The consortium is largely Finnish and is co-ordinated by the Helsinki Technical University. SAMS’ role is to study statistical properties of synthetic aperture radar (SAR) images and relate these to ridge parameters.

Shipping Ice Ice sheets Arctic
9. Greenland Arctic Shelf Ice and Climate Experiment

-Quantify changes in ice dynamics and characteristics resulting from the switch in AO phase -Establish a climate record for the region north of Greenland through the retrieval and analysis of sediment cores -Improve an existing dynamic-thermodynamic sea ice model, focusing on the heavily deformed ice common in the region -Relate the region-specific changes which have occurred to the larger-scale Arctic variablity pattern -Place the recent ice and climate variability for this critical region into the context of long term climate record, as reconstructed from sediment cores

Climate variability Climate Sea ice Environmental management Climate change Modelling Ice Arctic Ice cores Temporal trends
10. Sea Ice Thickness Observation System

SITHOS (Sea Ice Thickness Observation System) is also a three-year EU Framework 5 project. The Nansen Environmental Remote Sensing Centre (NERSC) will co-ordinate six institutions in the development of an integrated system for measuring sea ice thickness in the Arctic Ocean. Several approaches for obtaining ice thickness will be used, including novel flexural-wave methods, remote sensing and electromagnetic induction techniques. SAMS’ role is to provide data from UK submarines and aid in the development of the novel tiltmeter-based instruments. Data will be used to improve sea ice models and validate the new CRYOSAT satellite sensors. The resulting synoptic thickness monitoring network will be used to investigate the postulated dramatic thinning in the Arctic Ocean sea ice cover as a result of climate change.

Shipping Ice Ice sheets Arctic
11. RADNOR - Radioactive dose assessment improvements for the Nordic marine environment: Transport and environmental impact of technetium 99 (99Tc) in marine ecosystems

Radioactivity in the Arctic environment is a central topic within environmental pollution issues. Increased discharges of technetium-99 (99Tc) from the nuclear fuel reprocessing plant Sellafield to the Irish Sea has caused public concerns in Norway. This project (acronym “RADNOR”) includes model and monitoring assessments and improvements, assessment of current and novel abiotic and biotic dose parameters and dose calculations and use of realistic climatic background scenarios in order to assess corresponding consequences for transport of radioactive pollutants. RADNOR consists of three main components: part 1, the determination of levels and time series of 99Tc in benthic and pelagic food webs; part 2, containing working packages on improvements to the understanding of site-specific and time-dependent sediment-water interactions (KD), kinetics of accumulation (CF) and body distribution in marine organisms, including contaminated products for the alginate industry and part 3, dealing with model hindcasts and observations for spreading of 99Tc from the Sellafield nuclear reprocessing plant during the 1990s and improvement of the NRPA dose assessment box model. From the model outputs, doses to man and environment will be calculated resulting in a valuable database for use within environmental management and for decision makers.

distribution coefficients (KD) RADNOR Long-range transport Spatial trends Contaminant transport concentration factors (CF) Radionuclides Modelling Oceanography Arctic Food webs Sediments Temporal trends Human intake Technetium 99
12. Seismological "Very Broad Band" Station (VBB-Station)

The new seismological broad band station KBS at Ny-Ålesund replaces a former WWSSN station operated by the Institute for Solid Earth Physics of the University of Bergen. Both instrumentation and data acquisition of the old station were inadequate to meet all the demands for highest data quality for today's modern seismological research. The high technical standard of the new stations instrumentation now fulfils all the requirements of a modern broad band station. Therefore this station is integrated into the international Global Seismological Network, GSN, for monitoring the world-wide seismic activity. Special interests focus on regional seismicity at and around Svalbard itself and along the ridges in the arctic ocean. KBS is an open station, e.g., any interested scientist or international organization os allowed to retrieve data of special interest. Data are routinely processed and stored at the IRIS Data Management Center in Seattle. Copies are also available at the Geoforschungszentrum Potsdam (GFZ).

Geology Seismology Geophysics Arctic
13. Submarine Operational And Research Environmental Database (SOARED)

The Submarine Operational And Research Environmental Database (SOARED)is comprised of a fixed relational environmental database using unclassified data collected during the Science Ice Exercises (SCICEX) during the past several years. It also includes publicly accessible gridded historical sound velocity, temperature and salinity data from 1900 from the US National Oceanographic Data Center. This project is a demonstration system to show ways to retrieve and analyze sound velocity, temperature and salinity profiles, bathymetry and ice thickness data using a mouse-driven GIS-based query.

Shelf seas Hydrography Mapping Spatial trends Sea ice Climate change Ice Oceanography Arctic GIS Data management Ocean currents Temporal trends
14. Arctic Social Science Data Center (ASDC)

A proposal has been submitted to the National Science Foundation titled: For Support of the Arctic Social Science Data Center at NSIDC, OPP-0119836.

Arctic social science Arctic Data management
15. The Arctic sea ice ecosystem in recent environmental changes

Biological materials obtained in the central Arctic Ocean at the FSU “North Pole stations” in 1975-1981 have shown that the multi-year ice and ice/water interface is of rich and diverse biotop inhabited by the large number of diatoms and invertebrate animals. Two main matter fluxes in the sea ice ecosystem may be distinguished: (1) the inflow of biogenous elements from water into the ice interior where they are assimilated by the microflora during photosynthesis (summer stage), and (2) the outflow – from ice to water - of the organic matter accumulated in the summer due to photosynthesis (winter stage). Accumulation of organic matter within the sea ice interior during the process of photosynthesis may be considered as an energy depot for organisms of the whole trophic network of the arctic sea ice ecosystem. Recent data from the SHEBA Ice Camp drifted within the Beaufort Gyre 1997-1998 have shown that: (1) sea ice diatoms are very scarce by species and numbers; (2) fresh water green algae are dominated by numbers and distributed within the whole sea ice thickness; (3) invertebrate animals within the sea ice interior are not indicated; (4) invertebrate animals from the ice/water interface are scarce by species and numbers; (5) concentrations of chlorophyll and nutrients in the sea ice are significantly lower of the average concentrations measured before in this region for the same period of time. Remarkable accumulation of the organic mater within the sea ice interior were not indicated.

Biological effects taxonomy Biology Sea ice Climate change Arctic Ocean Ice Biodiversity Arctic production sea ice biota
16. The Bowhead whale as a potential indicator species for monitoring the health of the western Arctic/Bering Sea ecosystem using blubber, histology, metal and mineral indices

I. Objectives: I.1. To determine the normal range of values (natural variability due to time of year, age, gender) for basic nutritional and health parameters (blubber characteristics, essential and non-essential elements, structure of basic tissues) in the bowhead whale. a. Blubber thickness (depth and girth), chemical composition (lipids, water, calories), and tissue structure (light microscopy and special stains) will be assessed. b. Essential and non-essential elements (heavy metals) will be measured in liver and kidney. c. Tissue structure (light microscopy) characteristics obviously related to nutritional status in liver (glycogen, lipid and lipofuscin stores), pancreas (zymogen granules), and intestine (mucosal microvilli) and any evidence of inactivity/atrophy will be examined. d. Documentation of "normal" structure of basic tissues and evaluation for evidence of disease will also be conducted. I.2. Using data from Objective 1 to identify the parameters most important in assaying the health status of other mysticetes residing in the Bering Sea or Western Arctic that are harvested or stranded. I.3. Using data from Objective 1 to help determine the role of the bowhead whale as an indicator of ecosystem health and development of an optimized protocol for assessing mysticete health for the Bering Sea and Western Arctic, and other regions.

Biological effects Biology Organochlorines Heavy metals Arctic Persistent organic pollutants (POPs) Ecosystems Marine mammals
17. Human and chemical ecology of Arctic pathways by marine pollutants

1. Research area # 2 in the 1998/99 Announcement of Opportunity by CIFAR, "Study of anthropogenic influences on the Western Arctic/Bering Sea Ecosystem", and 2. Research area #4 in the 1998/99 Announcement of Opportunity by CIFAR, "Contaminant inputs, fate and effects on the ecosystem" specifically addressing objectives a-c, except "effects." a. "Determine pathways/linkages of contaminant accumulation in species that are consumed by top predators, including humans, and determine sub-regional differences in contaminant levels..." b. "Use an ecosystems approach to determine the effects of contaminants on food web and biomagnification." c. "Encourage local community participation in planning and implementing research strategies." The objectives of Phase I, Human Ecology Research are to: 1. Document reliance by indigenous arctic marine communities in Canada, Alaska and Russia on arctic resources at risk from chemical pollutants; and, 2. Incorporate traditional knowledge systems of subsistence harvesting. The human ecology components of the project were conducted within the frameworks of indigenous environmental knowledge and community participation. Using participatory mapping techniques, semi-structured interviews and the direct participation of community members in research design, data collection and implementation, research and data collection on the human ecology of indigenous arctic marine communities was undertaken in the communities of Holman, NWT (1998), Wainwright, Alaska (1999), and is underway in Novoe Chaplino, Russia. (2000).

Biology Organochlorines PCBs Fish Indigenous people Contaminant transport Stable isotopes Exposure Arctic Persistent organic pollutants (POPs) Food webs Ecosystems Marine mammals
18. Concentrations and interactions of selected elements in tissues of four marine mammal species harvested by Inuit hunters in arctic Alaska, with an intensive histologic assessment, emphasizing the beluga whale

The first part of the present study evaluated tissue concentrations of twelve essential and non-essential elements in four arctic marine mammal species important as subsistence resources to indigenous Alaskans. Species sampled included: bowhead whales, beluga whales, ringed seals, and polar bears. Concentrations of As, Cd, Co, Cu, Pb, Mg, Mn, Hg, Mo, Se, Ag, and Zn, were analyzed in liver, kidney, muscle, blubber, and epidermis (the latter in cetaceans only). Elements that were identified as having tissue concentrations, which in domesticated species would have been considered higher than normal and/or even toxic, were Cd, Hg, Ag, and Se. However, the concentrations of these elements were consistent with previous reports for arctic marine mammals. Remaining elements were at concentrations within normal ranges for domesticated species, although Cu was found frequently at concentrations that would be considered marginal or deficient in terrestrial domesticated animals. Across-species comparisons revealed that Cd was highest in kidney, followed by liver in all four species. Its concentrations were frequently correlated with Cu, Zn, Hg, and Se. Cadmium accumulated with age in bowhead and beluga whales, especially in liver and kidney. The relationships between Cd and Hg, and between Cd and Se were believed to be due to mutual accretion with age, although direct interactions could not be ruled out, especially with respect to Cd and Se. Associations between Cd and Cu, and Cd and Zn were potentially attributable to mutual binding with the inducible protein, metallothionein. This assumption was supported by the observation that Cd:Zn ratios in liver and kidney displayed a significant linear relationship to age and that this ratio either increased slightly (in kidney and liver of bowheads) or remained constant (in kidney and liver of belugas) with age. In general, Se was highest in liver and kidney of all four species, where it was frequently at concentrations that would have been deemed elevated or toxic for domesticated species, although within ranges previously reported for arctic marine mammals. Selenium increased with age indices, and was highly correlated with Hg, and often with Cd as well. Mercury also increased with age, and liver contained the highest tissue concentration in the cetacean and pinniped species. The pattern of Se accumulation in polar bears differed, with highest concentrations found in kidney, which suggested that this tissue may be the primary site for Hg detoxification in this species, as is the case for terrestrial mammals. Compared to the other three species, bowhead whales had very low Hg concentrations in all tissues. The highly significant linear relationship between Hg and Se noted in various tissues (particularly liver) of all four species was presumed due to binding of these two elements to each other following demethylation of MHg. This assumption was supported by the observations that while Se and Hg both accumulated with age, the fraction of total Hg that was composed of MHg decreased with age. The quantity that represented the difference between total Hg measured directly and calculated total Hg [i.e., SHg = Hg(II) + MHg], also increased with age in beluga liver. This connoted that a portion of the total Hg present was in an organic form other than MHg, and that this form accumulated with age. Alternatively, this portion, which was apparently not measured by either the Hg(II) or MHg procedures, may have been lost during extraction. Species in this study had mean hepatic Hg:Se molar ratios that were below unity. This implies that Hg concentrations may have been below some threshold level, after which subsequent accumulation proceeds in a 1:1 molar ratio fashion with Se. Alternatively, it might suggest that a 1:1 Hg:Se molar ratio is not a prerequisite for protection from Hg toxcosis among marine mammals, because none of the animals in the present study exhibited lesions typically associated with Hg toxicosis. In beluga liver, concentrations of Ag were elevated when compared to domesticated species. The only element that showed a significant linear association to Ag was Cu—a relationship that was observed in all four species. This suggested that Ag and Cu may be associated through a common ligand, possibly metallothionein. The association between Ag and Se in beluga liver was less strong than that between Hg and Se; moreover, Ag did not increase with age. These findings indicate that Ag probably does not compete with Hg for Se binding, and therefore is unlikely to substantially inhibit detoxification of Hg in beluga whales. In the second portion of this research, tissues from bowhead whales, beluga whales and ringed seals were examined at both the gross and light microscopic level. The purpose of this evaluation was three-fold: to describe the normal histologic appearance of tissues; to perform a routine histologic survey of tissues that would contribute to a general health assessment, and; to scrutinize tissues for lesions that might support a diagnosis of toxicosis caused by Cd, Hg, Ag, or Se. Tissues examined were chosen on the basis of their propensity to be targets for toxicologic injury from the specified elements (with the exception of brain) and included, but were not limited to, the tissues analyzed chemically. Special stains were used to identify particular pigments or tissue components. Overall, the bowhead whales evaluated appeared healthy and had low parasite burdens. The most common lesion, which was observed in all bowheads, was a non-inflammatory chronic renal periglomerular and interstitial fibrosis. This lesion was not typical of Cd-induced nephropathy, and it did not appear to be associated with renal Cd burdens. Nevertheless, thresholds of Cd-induced renal injury are not known for cetacean species, and more whales need to be examined histologically in conjunction with analysis of tissue Cd residues. Acute myodegeneration was observed in cardiac and/or skeletal muscle of a few bowheads, and was presumed to reflect a hunting-induced exertional myopathy. The beluga whales examined were generally in good body condition and appeared healthy grossly, but they had much higher parasite burdens than bowhead whales. In particular, prevalence in belugas of pulmonary nematodiasis was high, being especially common among whales obtained from Pt. Hope compared to those from Pt. Lay. Grossly, firm, caseous nodules were associated with lungworms, while histologically, the associated pulmonary changes ranged from mild chronic inflammation and focal granuloma formation to catarrhal granulomatous and eosinophilic verminous bronchopneumonia. Another change observed in some belugas and believed to be associated with lungworm infection, was multifocal pulmonary arterial medial hypertrophy and degeneration. Beluga whales harvested at Pt. Lay (summer) frequently showed evidence of hepatic and pancreatic atrophy, while whales taken at Pt. Hope (spring) did not. This was believed to result from anorexia during migration—a supposition corroborated by the lack of stomach contents among Pt. Lay whales. Another prominent histologic finding among belugas was hepatic telangectasia, which occurred with significantly greater frequency and severity in Pt. Hope belugas than in those from Pt. Lay. The etiology and significance of this lesion could be not be ascertained, although it was not believed to be associated with any of the elements analyzed in this study. Mild thickening of Bowman’s capsule was seen frequently in belugas. However, this lesion was not typical of Hg or Cd-induced nephropathies, and did not appear correlated with kidney concentrations of these metals. This lesion was believed to be a normal consequence of aging in belugas, although a metal etiology for it could not be excluded irrefutably. In general, ringed seals were in good body condition and appeared healthy on gross examination. Among seals evaluated histologically, the most common finding was a mild, chronic, focal or periportal hepatitis, with focal hepatocellular necrosis sometimes apparent. Although a metal etiology for this lesion could not be definitively ruled out, in the absence of other lesions that would support a diagnosis of metal toxicosis, an infectious etiology was considered more credible. Two out of sixteen seals had embryologic remnants (an epidermoid cyst and an ultimobranchial cyst)—lesions that are usually considered incidental. While no toxic (metal or otherwise) etiology could be ascertained for these lesions, the incidence of retained embryologic remnants seemed high. A number of xenobiotics are known to be endocrine-disruptors, and the potential for such an etiology among these seals should be examined further. Lipofuscin deposition was ubiquitous among all three species examined histologically. Lipofuscin was most prevalent in hepatocytes, but also commonly was observed in various other tissue and cell types, especially in cardiac and skeletal myocytes, and in uriniferous tubular epithelial cells. The third portion of this study employed autometallographic (AMG) development of light microscopic tissue sections to amplify and localize deposition of inorganic Hg in liver and kidney of beluga and bowhead whales. No staining occurred among bowhead tissues, confirming the extremely low concentration of Hg determined through chemical analyses. In beluga kidney sections, AMG granules were seen throughout the uriniferous tubular epithelium, showing that Hg deposits throughout the nephric tubule, and not solely in the proximal tubular epithelium. In liver tissue, AMG granules were deposited primarily in periportal regions among whales with lower hepatic Hg burdens. In addition to periportal deposition, AMG granules were observed in pericentral and mid-zonal regions in the belugas sampled that had higher liver Hg concentrations (generally older animals). Granules were densely concentrated in stellate macrophages, especially near portal triads. Granules also were distributed in hepatocellular cytoplasm, generally concentrated toward the bile cannalicular domain of the cell. Granules were discrete, potentially indicating that Hg was confined within lysosomes. These observations suggested that inorganic Hg deposits initially in periportal regions of young animals, with subsequent accumulation occurring pericentrally, and finally, midzonally as the whales age. Computer-assisted densitometric analysis was used for semi-quantitative evaluation of AMG staining intensities. These AMG staining intensities were well correlated with concentrations of Hg determined via chemical analysis. Areas with AMG-staining were identified and compared with location of lipofuscin in the same field, visualized with fluorescent microscopy. While AMG granules and lipofuscin deposits sometimes were co-localized, they more often were not. In addition, abundant lipofuscin deposition was seen in livers of younger belugas with little to no Hg-catalyzed AMG staining. Also, lipofuscin concentrated predominantly in pericentral regions. These observations suggested that in the healthy marine mammals of this study, marked hepatic lipofuscin deposition most often occurred independently of Hg accumulation. Consequently, hepatic lipofuscin is likely to be a poor indicator of Hg-induced damage in belugas. The abundant lipofuscin deposition in livers of marine mammals was interpreted as most likely denoting a heightened exposure to oxidative stress that is probably inherent to a marine mammalian existence. These oxidative stressors may include a diet high in polyunsaturated fatty acids (PUFAs), alternating hypoxia and abundant oxygenation, and periodic bouts of anorexia associated with migration.

histology Biological effects Heavy metals health assessment Polar bear Arctic histopathology Marine mammals
19. Radionuclide contaminant burdens in arctic marine mammals harvested during subsistence hunting

We conducted gamma spectrometric analyses on more than 200 arctic marine mammal tissue samples. These samples were primarily provided by subsistence hunters from northern Alaska, with a smaller number of samples from the Resolute region in Canada. The majority of samples (>90% ) had detectable levels of the anthropogenic radionuclide 137Cs, with a mean level observed in all samples of 0.67 Bq kg-1 dry weight ±0.81 (SD). Converted to wet weight, the mean was 0.21 Bq kg-1 ±0.19 SD. The median activity observed was 0.45 Bq kg-1 dry weight (0.18 Bq kg-1 wet weight) with a range from detection limits to 6.7 Bq kg-1dry weight (1.1 Bq kg-l wet weight). These findings confirm expectations that current anthropogenic gamma emitter burdens in marine mammals used in the North American Arctic as subsistence food resources are well below activities that would normally merit public health concern (~1000 Bq kg-1 wet weight). Some differences among species and tissues were observed. Beluga tissues had slightly higher mean burdens of 137Cs overall, and epidermis and muscle tissues in bowhead and beluga whales typically had higher burdens than other tissues analyzed. Low levels of the neutron activation product l08mAg (half-life 418 yr.), probably bioaccumulated from bomb fallout sources, were observed in 16 of 17 beluga livers analyzed, but were not found in any other tissues of beluga or in any other species sampled. A subset of 39 samples of various tissues was analyzed for the alpha and beta emitters 239,240Pu and 90Sr. Plutonium levels were near the threshold of detectability (~0.1 Bq kg-1 dry weight) in 6 of the 39 samples; all other samples had no detectable plutonium. A detectable level of 90Sr (10.3 ±1.0 Bq kg-1 dry weight) was observed in only one of the 39 samples analyzed, a bowhead epidermis sample. Although the accumulation of 108mAg has not been previously reported in any marine mammal livers, all of our analytical measurements indicate that only very low levels of anthropogenic radioactivity are associated with marine mammals harvested and consumed in the North American Arctic.

silver-108m cesium-137 Radionuclides Arctic Marine mammals
20. Polar Exchange at the Sea Surface (POLES)

Our broad area of enquiry is the role of polar regions in the global energy and water cycles, and the atmospheric, oceanic and sea ice processes that determine that role. The primary importance of our investigation is to show how these polar processes relate to global climate.

Atmospheric processes polar cloud dynamics ice dynamics surface radiation and cloud forcing Climate variability Climate Sea ice Climate change surface heat and mass balance polar atmospheric processes ice-ocean models arctic climate Modelling Ice Oceanography Arctic SEARCH Atmosphere Ocean currents cryosphere ice thickness