Sample records for lake thun switzerland

  1. Overdeepened glacigenic landforms in Lake Thun (Switzerland) revealed by a multichannel reflection seismic survey

    NASA Astrophysics Data System (ADS)

    Fabbri, Stefano; Herwegh, Marco; Schlunegger, Fritz; Hübscher, Christian; Weiss, Benedikt J.; Schmelzbach, Cédric; Horstmeyer, Heinrich; Buechi, Marius W.; Anselmetti, Flavio S.

    2016-04-01

    Recently acquired high-resolution multibeam bathymetry, in combination with a 2D multichannel reflection seismic campaign on perialpine Lake Thun (Switzerland) reveals new insights into the diverse geometry of the lake basin and a so far unknown subaquatic moraine crest with unprecedented clarity. These new data will improve our comprehension concerning the retreat phases of the Aare glacier, the morphology of its proximal deposits and the facies architecture of the subglacial units. The overdeepened basin of Lake Thun was formed by a combination of tectonically predefined weak zones and glacial erosion during the last glacial periods. The new data indicate that below the outermost edge of a morphologically distinct platform in the south eastern part of the lake basin, a ridge structure marked by strong reflection amplitudes occurs. This structure is interpreted as a subaquatic terminal moraine crest, most likely created by a slightly advancing or stagnant grounded Aare glacier during its major retreating phase. The terminal moraine smoothly transforms downstream into well distinguishable foresets with internally recognisable layering, which dip steeply towards the deepest part of the basin, eventually transforming into bottomsets. This depositional sequence formed by the fore- and bottomsets represents ˜50% of the overall sediment volume that fills the basin and was deposited while the glacier was stagnant, interpreted to represent a rather short period of time of a few hundreds of years. This sequence is overlain by lacustrine deposits formed by late-glacial and Holocene laminated muds comprising intercalated turbidites (Wirth et al. 2011). Little is known about the exact timing and behaviour of retreating glaciers between their recessional phase from the Alpine foreland to the deglaciation of the inner-Alpine ice cap, mostly due to the lack of well-developed moraines that indicate glacial stabilization or slight readvance. Findings from pollen analyses by

  2. A subaquatic moraine complex in overdeepened Lake Thun (Switzerland) unravelling the deglaciation history of the Aare Glacier

    NASA Astrophysics Data System (ADS)

    Fabbri, S. C.; Buechi, M. W.; Horstmeyer, H.; Hilbe, M.; Hübscher, C.; Schmelzbach, C.; Weiss, B.; Anselmetti, F. S.

    2018-05-01

    To investigate the history of the Aare Glacier and its overdeepened valley, a high-resolution multibeam bathymetric dataset and a 2D multi-channel reflection seismic dataset were acquired on perialpine Lake Thun (Switzerland). The overdeepened basin was formed by a combination of tectonically predefined weak zones and glacial erosion during several glacial cycles. In the deepest region of the basin, top of bedrock lies at ∼200 m below sea level, implying more than 750 m of overdeepening with respect to the current fluvial base level (i.e. lake level). Seismic stratigraphic analysis reveals the evolution of the basin and indicates a subaquatic moraine complex marked by high-amplitude reflections below the outermost edge of a morphologically distinct platform in the southeastern part of the lake. This stack of seven subaquatic terminal moraine crests was created by a fluctuating, "quasi-stagnant" grounded Aare Glacier during its overall recessional phase. Single packages of overridden moraine crests are seismically distuinguishable, which show a transition downstream into prograding clinoforms with foresets at the ice-distal slope. The succession of subaquatic glacial sequences (foresets and adjacent bottomsets) represent one fifth of the entire sedimentary thickness. Exact time constraints concerning the deglacial history of the Aare Glacier are very sparse. However, existing 10Be exposure ages from the accumulation area of the Aare Glacier and radiocarbon ages from a Late-Glacial lake close to the outlet of Lake Thun indicate that the formation of the subaquatic moraine complex and the associated sedimentary infill must have occurred in less than 1000 years, implying high sedimentation rates and rapid disintegration of the glacier. These new data improve our comprehension of the landforms associated with the ice-contact zone in water, the facies architecture of the sub- to proglacial units, the related depositional processes, and thus the retreat mechanisms of

  3. Sediment record and atmospheric deposition of brominated flame retardants and organochlorine compounds in Lake Thun, Switzerland: lessons from the past and evaluation of the present.

    PubMed

    Bogdal, Christian; Schmid, Peter; Kohler, Martin; Müller, Claudia E; Iozza, Saverio; Bucheli, Thomas D; Scheringer, Martin; Hungerbühler, Konrad

    2008-09-15

    Chronology of brominated fame retardants (BFRs), a class of currentlywidely used chemicals, was compared to the respective historical profiles of legacy organochlorine compounds in three dated sediment cores from a prealpine lake (Lake Thun, Switzerland). Concentrations of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) started to increase in the 1980s-1990s. In the more recent sediment layers, PBDEs still had steady or increasing concentrations, whereas for HBCDs one sediment core revealed a decreasing trend. In contrast to the contemporary BFRs, concentrations of legacy organochlorines, such as polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), and dichlorodiphenyl trichloroethane (DDT), peaked in deeper sediment layers deposited some decades ago. Measurements of atmospheric deposition and evaluation of wastewater discharges pointtoward deposition on the lake surface as a relevant input pathway and wastewater as a minor source of POPs in Lake Thun. The effect of the environmental awareness and the regulations taken in the 1970s to reduce environmental pollution of organochlorines is well reflected in the analyzed sediment cores. The sediment burden closely follows estimated time trends of consumption and emission of PCBs and DDT. The current residues in sediment of BFRs are still lower than the historical peak levels of organochlorines. However, current atmospheric deposition of BFRs is similar to deposition of PCBs. Considering the high amount of BFRs presently stocked in the anthroposphere in flame proofed materials, further measures to reduce emissions during BFRs life cycle are recommended to prevent high environmental pollution as it occurred for the organochlorine compounds.

  4. Modelling geomorphic responses to human perturbations: Application to the Kander river, Switzerland

    NASA Astrophysics Data System (ADS)

    Ramirez, Jorge; Zischg, Andreas; Schürmann, Stefan; Zimmermann, Markus; Weingartner, Rolf; Coulthard, Tom; Keiler, Margreth

    2017-04-01

    Before 1714 the Kander river (Switzerland) flowed into the Aare river causing massive flooding and for this reason the Kander river was deviated (Kander correction) to lake Thun. The Kander correction was a pioneering hydrological project and induced a major human change to the landscape, but had unintended hydrological and geomorphic impacts that cascaded upstream and downstream. For example doubling the catchment area of Lake Thun, which gave rise to major flood problems, cessation of direct sediment delivery to the Aare, and sediment flux to lake Thun forming the Kander delta. More importantly the Kander correction shortened the Kander river and substantially increased the slope and bed shear of the Kander upstream from the correction. Consequently impacts of the correction cascaded upstream as a migrating knickpoint and eroded the river channel at unprecedented rates. Today we may have at our disposal the theoretical and empirical foundations to foresee the consequences of human intervention into natural systems. One method to investigate such geomorphic changes are numerical models that estimate the evolution of rivers by simulating the movement of water and sediment. Although much progress has been made in the development of these geomorphic models, few models have been tested in circumstances with rare perturbations and extreme forcings. As such, it remains uncertain if geomorphic models are useful and stable in extreme situations that include large movements of sediment and water. Here, in this study, we use historic maps and documents to develop a detailed geomorphic model of the Kander river starting in the year 1714. We use this model to simulate the extreme geomorphic events that preceded the deviation of the Kander river into Lake Thun and simulate changes to the river until conditions become relatively stable. We test our model by replicating long term impacts to the river that include 1) rates of incision within the correction, 2) knickpoint

  5. Sedimentary records of trace elements from large European lakes (Switzerland) document historic to recent freshwater pollution and climate-induced runoff variations

    NASA Astrophysics Data System (ADS)

    Thevenon, F.; Wirth, S. B.; Fujak, M.; Poté, J.; Thierry, A.; Chiaradia, M.; Girardclos, S.

    2011-12-01

    Continuous sedimentary records of anthropogenic and natural trace elements determined by ICPMS, from 5 large and deep perialpine lakes from Central Europe (Switzerland), evidence the environmental impacts of industrial fossil fuel pollution. In fact, the greatest increase in heavy metal pollution was registered at all the studied sites following the European industrial revolution of ca. AD 1800; with the highest values during the middle part of the 20th century. On a regional scale, anthropogenic heavy metal input subsequently stopped increasing thanks to remediation strategies such as the implementation of wastewater treatment plants (WWTPs). On the other hand, the discharge of industrial treated wastewaters into Vidy Bay of Lake Geneva during the second part of the 20th century involved the sedimentation of highly contaminated sediments in the area surrounding the WWTP outlet pipe discharge; less than 4 km from the main supply of drinking water of Lausanne (127'000 hab.). Microbial analyses furthermore reveal i) high increase in bacterial densities following the lake eutrophication in the 1970s, and that ii) the related sediments can be considered as a reservoir of antibiotic resistant bacteria/genes (of human origin). We finally compare instrumental hydrological data over the last century with variations of lithogenic trace elements (e.g., titanium) as registered in three large lakes (Brienz, Thun and Bienne) connected by the River Aar. This task allows to better constraining the runoff variations on a regional scale over the last decades for the the River Aar, and its possible increase under warming climate conditions in the European Alps.

  6. Contrasting temporal trends and relationships of total organic carbon, black carbon, and polycyclic aromatic hydrocarbons in rural low-altitude and remote high-altitude lakes.

    PubMed

    Bogdal, Christian; Bucheli, Thomas D; Agarwal, Tripti; Anselmetti, Flavio S; Blum, Franziska; Hungerbühler, Konrad; Kohler, Martin; Schmid, Peter; Scheringer, Martin; Sobek, Anna

    2011-05-01

    Historical records of total organic carbon (TOC), black carbon (BC), and polycyclic aromatic hydrocarbons (PAHs) were reconstructed in dated sediment cores from four nearby lakes in central Switzerland. In the sub-Alpine Lake Thun, located at 558 m a.s.l., the proximity to anthropogenic emission sources is reflected in higher input of BC and PAHs into sediments with fluxes only slightly decreasing during the last decades. PAH/BC ratios are relatively high and correlation between levels of total PAHs and BC is almost inexistent in Lake Thun, probably due to the presence of less condensed forms of the BC spectrum (char BC) that is underestimated with the chemothermal oxidation method applied in this study. The sediment profiles of TOC, BC, and PAHs are noticeably different in the mountain lakes located around 2000 m a.s.l. In Lake Engstlen, the PAH/BC ratios, as well as the correlation between PAHs and BC, point towards appreciable amounts of predominantly light soot particles. Light soot particles have higher mobility and can, therefore, be efficiently transported to this remote site. The proglacial Lake Oberaar is shown to be a receptor of BC and PAHs released by the fast melting adjacent glacier acting as a secondary source for these conservative species temporarily stored in the glacier ice. Finally, Lake Stein is in strong contrast to all other lakes. High flux of BC into Lake Stein, combined with constant temporal evolutions of BC and PAHs, and in particular BC/TOC ratios approaching 100% are all strong indications for a geogenic presence of graphite in its catchment area.

  7. Combining XAS speciation and Zn isotopes to track past eutrophication in lake sediments : The example of Baldeggersee (Switzerland)

    NASA Astrophysics Data System (ADS)

    Noël, V. S.; Voegelin, A.; Jouvin, D.; Louvat, P.; gelabert, A.; Mueller, B.; Benedetti, M. F.; Juillot, F.

    2011-12-01

    Among transition elements, Zn has attracted a great deal of interest because it is an essential nutrient at low concentrations, but it can also be toxic when present at high concentrations in ecosystems (Morel et al., 2003). In the present study, the isotopic signature and crystal-chemical of Zn were followed along a sediment core from a prealpine lake that experienced a marked eutrophication in order to explore the potential of this approach at tracking past environmental conditions of continental lake-catchment systems. Lake Baldeggersee (Luzern, Switzerland) is located at an elevation of 900 m in the Swiss Prealps. It experienced a period of strong eutrophication due to intensive farming in its catchment (Lotter et al., 1997). These led to the formation of varved sediments over one century prior to artificial lake aeration (Wehrli et al., 1997). This enabled us to correlate Zn speciation and isotopic signatures to the history of the water column. Results indicate that both Zn speciation and isotopes are distinct between sediments deposited during mesotrophic and eutrophic conditions in the water column: During the mesotrophic period, sedimentation was mainly detrital and Zn is mainly found associated with clay minerals in the sediments. During the eutrophic period, sedimentation was dominated by biological activity in the lake and Zn mainly occurs as ZnS in the sediments. Zn isotopes recorded these changes in the sedimentation regime, with δ66ZnJMC values around +0.2 % for the sediments of the mesotrophic period and δ66ZnJMC values around 0 % for the sediments of the eutrophic period. Comparison with the results from a study on the seasonal variation of the isotope signature of Zn in settling sediment of another prealpine lake (Peel et al., 2010) suggests that the enrichment in light Zn isotopes in the eutrophic sediments is in line with predominant Zn input with settling biomass (algae). Since lake eutrophication is mainly related to hydrological conditions

  8. Gyre formation within embayments of a large lake (Lake Geneva, Switzerland)

    NASA Astrophysics Data System (ADS)

    Razmi, A.; Barry, D.; Bouffard, D.; Le Dantec, N.; Lemmin, U.; Wuest, A.

    2013-12-01

    Numerical simulations were carried out to examine gyre formation within open, wide lacustrine embayments. The present study was motivated by observed differences in gyre formation within two open and wide embayments (located at Vidy and Morges in Lake Geneva, Switzerland). These two embayments are located within about 3 km of each other on the northern shore of Lake Geneva, and are subjected to similar pelagic currents. Vidy is deeper and has a greater aspect ratio than Morges. The flow field in the embayments was modeled using a previously validated 3D hydrodynamic model (Delft3D-FLOW). The model solved the Reynolds-Averaged Navier-Stokes equations, combined with a k-ɛ turbulence closure in σ (lakebed-following) coordinates. Our study focused on the influence of the embayment geometry on the (uniform) longshore (pelagic) current, specifically the occurrence and magnitude of circulation within the embayment. We built a set of numerical experiments using synthetic embayments, and systematically examined embayment geometry, thereby capturing the differences between the Vidy and Morges embayments. The numerical experiments considered single rectilinear embayments with different aspect ratios (i.e., 1-6), depth, shore-parallel flow rates, and embayment corner angle between 0°-50°. The circulation magnitude changes abruptly for an angle of about 40°. Embayments with angles greater than 40° have much greater circulation then those with lesser angles, other factors remaining the same. Of the factors considered (i.e., aspect ratio, offshore current velocity, corner angle, bottom slope, and viscosity), bottom slope and the viscosity have almost no impact on embayment circulation. For uniform offshore current patterns, gyres form in embayments with large aspect ratios (up to ~3). For the Vidy and Morges embayments, the results showed that gyre formation is more likely in Morges due to its smaller aspect ratio, a finding that is supported by field data gathered in

  9. Effect of phosphorous concentrations on sedimentary distributions and isotopic composition of algal lipid biomarkers in lakes from central Switzerland

    NASA Astrophysics Data System (ADS)

    Ladd, N.; Dubois, N.; Schubert, C. J.

    2015-12-01

    Lakes in the Swiss central plateau experienced increasing anthropogenic phosphorous loading throughout much of the 20th century. Since the 1980s concerted remediation efforts on the part of the Swiss government have significantly reduced P concentrations in most lakes and reversed previous eutrophication. However, P concentrations remain elevated above their preindustrial levels in many sites. High quality monitoring of lake nutrient levels since the 1950s, along with several lakes of wide-ranging P concentrations in close proximity, make central Switzerland an ideal location for studying the ways in which nutrient loading affects the organic composition of lacustrine sediments. Results of such studies can be used to develop proxies of eutrophication in sites where fewer historical data exist, and to reconstruct historical P concentrations in local lakes from the time before record keeping began. We analyzed the distributions of algal lipid biomarkers from surface sediment and sediment traps collected in the spring of 2015 from ten lakes with variable P concentrations in central Switzerland. Sedimentary lipid distributions from these lakes confirm that biomarkers associated with algal and cyanobacterial sources are more abundant in the sediment of lakes with greater P loading. The dry sedimentary concentrations of biomarkers such as brassicasterol (primarily diatom source) and diplopterol (cyanobacteria source), as well as the less source specific short-chain n-alkanols, linearly increase from 0.3 - 1.9 μg/g as total phosphorous in the upper water column increases by 1 μg/L over a range of 7 - 50 μg/L. We also present preliminary hydrogen isotope data from these biomarkers. Hydrogen isotopes of algal lipids primarily reflect the source water in which the algae grew, and this relationship has been developed as a paleohydrologic proxy. However, laboratory cultures of marine algae demonstrate that they discriminate more against 2H under nutrient replete conditions

  10. Bottom-current and wind-pattern changes as indicated by Late Glacial and Holocene sediments from western Lake Geneva (Switzerland)

    USGS Publications Warehouse

    Girardclos, S.; Baster, I.; Wildi, W.; Pugin, A.; Rachoud-Schneider, A. -M.

    2003-01-01

    The Late-Glacial and Holocene sedimentary history of the Hauts-Monts area (western Lake Geneva, Switzerland) is reconstructed combining high resolution seismic stratigraphy and well-dated sedimentary cores. Six reflections and seismic units are defined and represented by individual isopach maps, which are further combined to obtain a three-dimensional age-depth model. Slumps, blank areas and various geometries are identified using these seismic data. The sediment depositional areas have substantially changed throughout the lake during the end of the Late-Glacial and the Holocene. These changes are interpreted as the result of variations in the intensity of deep lake currents and the frequency of strong winds determining the distribution of sediment input from the Versoix River and from reworking of previously deposited sediments within the lacustrine basin. The identified changes in sediment distribution allowed us to reconstruct the lake's deep-current history and the evolution of dominant strong wind regimes from the Preboreal to present times.

  11. STS-42 Earth observation of the Rhone River / Lake Geneva in Switzerland

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-42 Earth observation taken aboard Discovery, Orbiter Vehicle (OV) 103, shows the Rhone River flowing into Lake Geneva in western Switzerland (46.0N, 7.0E). The sharp change in the valley's orientation is a feature of this view. Several times during cold periods of the Earth's history (the geologically recent Ice Ages of the last 1.5 million years or so), this valley has been filled with ice flowing off the mountain ranges. Ice erosion has widened and lowered the valley. The surrounding mountain chains include the highest peak in Europe, Mont Blanc (15,781 feet) on the French-Italian border, and the well-known Matterhorn (14,130) feet on the Swiss-Italian border. Ice-sculpting has generated the characteristically sharp ridges and pointed peaks of the Alps.

  12. Late-glacial and early Holocene changes in vegetation and lake-level at Hauterive/Rouges-Terres, Lake Neuchâtel (Switzerland)

    NASA Astrophysics Data System (ADS)

    Magny, Michel; Thew, Nigel; Hadorn, Philippe

    2003-01-01

    Palynological and sedimentological analyses of a sedimentary sequence sampled at Hauterive/Rouges-Terres, Lake Neuchâtel (Switzerland) provide documentation of changes in vegetation and lake-level during the Bølling, Younger Dryas and Preboreal pollen zones, and have allowed a comparison with sequences covering the same period from other sites located in the western part of the Swiss Plateau. The Juniperus-Hippophaë zone (regional pollen assemblage zone (RPAZ) CHb-2, first part of the Bølling, ca. 14 650-14 450 cal. yr BP) was characterised by a generally low lake-level. A weak rise occurred during this zone. The Juniperus-Hippophaë to Betula zone transition coincided with a lake-level lowering, interrupted by a short-lived but marked phase of higher lake-level recorded at the neighbouring site of Hauterive-Champréveyres, but not present at Hauterive/Rouges-Terres owing to an erosion surface. Shortly after the beginning of the Betula zone (RPAZ CHb-3, second part of the Bølling, ca 14 450-14 000 cal. yr BP), a marked rise in lake-level occurred. It was composed of two successive periods of higher level, coinciding with high values of Betula, separated by a short episode of relatively lower lake-level associated with raised values in Artemisia and other non-arboreal pollen. The last part of RPAZ CHb-3 saw a fall in lake-level. The lower lake-levels during RPAZ CHb-2 to early RPAZ CHb-3 can be correlated with the abrupt warming at the beginning of the Greenland Interstadial (GI) 1e thermal maximum. The successive episodes of higher lake-level punctuating the GI 1e might be linked to the so-called Intra-Bølling Cold Oscillations identified from several palaeoclimatic records in the North Atlantic area, and also documented in oxygen-isotope data sets from Swiss Plateau lakes. The Hauterive/Rouges-Terres lake-level record provides evidence for marked climatic drying through the second part of the Younger Dryas event (GS1), during the GS1-Preboreal (RPAZ CHb-4b-4

  13. Is Switzerland suitable for the invasion of Aedes albopictus [corrected]?

    PubMed

    Neteler, Markus; Metz, Markus; Rocchini, Duccio; Rizzoli, Annapaola; Flacio, Eleonora; Engeler, Luca; Guidi, Valeria; Lüthy, Peter; Tonolla, Mauro

    2013-01-01

    Over the last 30 years, the Asian tiger mosquito, Aedes albopictus, has rapidly spread around the world. The European distribution comprises the Mediterranean basin with a first appearance in Switzerland in 2003. Early identification of the most suitable areas in Switzerland allowing progressive invasion by this species is considered crucial to suggest adequate surveillance and control plans. We identified the most suitable areas for invasion and establishment of Ae. albopictus in Switzerland. The potential distribution areas linked to the current climatic suitability were assessed using remotely sensed land surface temperature data recorded by the MODIS satellite sensors. Suitable areas for adult survival and overwintering of diapausing eggs were also identified for future climatic conditions, considering two different climate change scenarios (A1B, A2) for the periods 2020-2049 and 2045-2074. At present, the areas around Lake Geneva in western Switzerland provide suitable climatic conditions for Ae. albopictus. In northern Switzerland, parts of the Rhine valley, around Lake Constance, as well as the surroundings of Lake Neuchâtel, appear to be suitable for the survival at least of adult Ae. albopictus. However, these areas are characterized by winters currently being too cold for survival and development of diapausing eggs. In southern Switzerland, Ae. albopictus is already well-established, especially in the Canton of Ticino. For the years 2020-2049, the predicted possible spread of the tiger mosquito does not differ significantly from its potential current distribution. However, important expansions are obtained if the period is extended to the years 2045-2074, when Ae. albopictus may invade large new areas. Several parts of Switzerland provide suitable climatic conditions for invasion and establishment of Ae. albopictus. The current distribution and rapid spread in other European countries suggest that the tiger mosquito will colonize new areas in Switzerland

  14. Is Switzerland Suitable for the Invasion of Aedes albopictus?

    PubMed Central

    Neteler, Markus; Metz, Markus; Rocchini, Duccio; Rizzoli, Annapaola; Flacio, Eleonora; Engeler, Luca; Guidi, Valeria; Lüthy, Peter; Tonolla, Mauro

    2013-01-01

    Background Over the last 30 years, the Asian tiger mosquito, Aedes albopictus, has rapidly spread around the world. The European distribution comprises the Mediterranean basin with a first appearance in Switzerland in 2003. Early identification of the most suitable areas in Switzerland allowing progressive invasion by this species is considered crucial to suggest adequate surveillance and control plans. Methodology/Principal Findings We identified the most suitable areas for invasion and establishment of Ae. albopictus in Switzerland. The potential distribution areas linked to the current climatic suitability were assessed using remotely sensed land surface temperature data recorded by the MODIS satellite sensors. Suitable areas for adult survival and overwintering of diapausing eggs were also identified for future climatic conditions, considering two different climate change scenarios (A1B, A2) for the periods 2020–2049 and 2045–2074. At present, the areas around Lake Geneva in western Switzerland provide suitable climatic conditions for Ae. albopictus. In northern Switzerland, parts of the Rhine valley, around Lake Constance, as well as the surroundings of Lake Neuchâtel, appear to be suitable for the survival at least of adult Ae. albopictus. However, these areas are characterized by winters currently being too cold for survival and development of diapausing eggs. In southern Switzerland, Ae. albopictus is already well-established, especially in the Canton of Ticino. For the years 2020–2049, the predicted possible spread of the tiger mosquito does not differ significantly from its potential current distribution. However, important expansions are obtained if the period is extended to the years 2045–2074, when Ae. albopictus may invade large new areas. Conclusions/Significance Several parts of Switzerland provide suitable climatic conditions for invasion and establishment of Ae. albopictus. The current distribution and rapid spread in other European

  15. Lake Constance

    Atmospheric Science Data Center

    2013-04-17

    ... the left-hand side of the image is bordered by Switzerland, Germany, and Austria, and has several names. Lake Constance (also written as ... is about 70 kilometers from the lakeside town of Konstanz, Germany. An annual Celtic music festival is hosted on the Swiss shores of Lake ...

  16. Lake Geneva, France/Italy/Switzerland

    NASA Image and Video Library

    1994-09-30

    STS068-243-076 (30 September-11 October 1994) --- Parts of the Swiss Cantons of Vaud and Valois, the French province of Chablis and parts of northwestern Italy are seen in this widely stretching image photographed from the Space Shuttle Endeavour. Pennine Alps, said to have been created 50 million years ago, have been reshaped by glaciers during Pleistocene. The glaciers created the wide valley of the Rhone River by scourting a pre-existing seam. The fertile Swiss Plateau runs northwest from the shore of Lake Geneva and is visible in lower left. The Franco-Swiss border is located in the center of the lake and follows a mountain divide east of Rhone Valley. Italy lies south of the Rhone.

  17. Dating of sediments from four Swiss prealpine lakes with (210)Pb determined by gamma-spectrometry: progress and problems.

    PubMed

    Putyrskaya, V; Klemt, E; Röllin, S; Astner, M; Sahli, H

    2015-07-01

    In this paper the most important problems in dating lake sediments with unsupported (210)Pb are summarized and the progress in gamma-spectrometry of the unsupported (210)Pb is discussed. The main topics of these studies concern sediment samples preparation for gamma-spectrometry, measurement techniques and data analysis, as well as understanding of accumulation and sedimentation processes in lakes. The vertical distributions of artificial ((137)Cs, (241)Am, (239)Pu) and natural radionuclides ((40)K, (210,214)Pb, (214)Bi) as well as stable trace elements (Fe, Mn, Pb) in sediment cores from four Swiss lakes were used as examples for the interpretation, inter-comparison and validation of depth-age relations established by three (210)Pb-based models (CF-CSR, CRS and SIT). The identification of turbidite layers and the influence of the turbidity flows on the accuracy of sediment dating is demonstrated. Time-dependent mass sedimentation rates in lakes Brienz, Thun, Biel and Lucerne are discussed and compared with published data. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. The history of Cesium-137 liquid emissions by Mühleberg Nuclear Power Plant (Switzerland) is recorded in Lake Biel sediments

    NASA Astrophysics Data System (ADS)

    Girardclos, Stéphanie; Faessler, Jérôme; Loizeau, Jean-Luc; Zehringer, Markus

    2014-05-01

    Lake sediments record changes happening in their upstream river catchment and regional environment which includes traces of artificial radionuclides emissions deriving from human activities. 137Cs emissions started worldwide in the early 1950's and peaked in 1963-64 due to nuclear bomb tests in the high atmosphere. A second 137Cs activity peak, due to the 1986 Chernobyl catastrophe is recorded in sediment archives from central Europe. These two events (1963/64 and 1986) serve routinely as time markers for recent lake records. Nuclear Power Plants (NPPs) are often constructed along river course for cooling purposes. Since 1972, Mühleberg NPP (central Switzerland) lies 18 km upstream Lake Biel and releases radioactive liquid emissions into the Aare river which adds to the diffuse - above mentioned - radioactive pollution, as revealed by Albrecht et al. (1995; 1998) and recently confirmed by Thevenon et al. (2013) from Lake Biel sediments. The water of Lake Biel is used as drinking water for ca. 60'000 inhabitants and its outflowing water is further used by downstream cities lying on the Aare-Rhine course such as Basel (200'000 inhab.) In this study, the 137Cs activity curve of a 90-cm-long sediment core (BIE10-8), retrieved in April 2010 from the central Lake Biel basin at ca. 50 m depth, and measured by gamma ray spectrometry using high resolution germanium detectors, confirms previous work and reveals a new peak for the year 1998-2000, as observed by Thevenon et al. (2013). This peak is most certainly due to Mühleberg NPP as shown by the good correlation with declared 137Cs liquid emissions indicating a significant increase in 1998-99. Decay corrected activity data, converted into 137Cs fluxes, point to water pollution by Mühleberg NPP in 1975-1985 as being similar to those linked to the catastrophic events in 1963-64 and 1986 (about 75%). As former study showed that Lake Biel sediments scavenge only a portion of the total radionuclide in water, i.e. 30-55% for

  19. Interfacing a one-dimensional lake model with a single-column atmospheric model: 2. Thermal response of the deep Lake Geneva, Switzerland under a 2 × CO2 global climate change

    NASA Astrophysics Data System (ADS)

    Perroud, Marjorie; Goyette, StéPhane

    2012-06-01

    In the companion to the present paper, the one-dimensional k-ɛ lake model SIMSTRAT is coupled to a single-column atmospheric model, nicknamed FIZC, and an application of the coupled model to the deep Lake Geneva, Switzerland, is described. In this paper, the response of Lake Geneva to global warming caused by an increase in atmospheric carbon dioxide concentration (i.e., 2 × CO2) is investigated. Coupling the models allowed for feedbacks between the lake surface and the atmosphere and produced changes in atmospheric moisture and cloud cover that further modified the downward radiation fluxes. The time evolution of atmospheric variables as well as those of the lake's thermal profile could be reproduced realistically by devising a set of adjustable parameters. In a "control" 1 × CO2 climate experiment, the coupled FIZC-SIMSTRAT model demonstrated genuine skills in reproducing epilimnetic and hypolimnetic temperatures, with annual mean errors and standard deviations of 0.25°C ± 0.25°C and 0.3°C ± 0.15°C, respectively. Doubling the CO2 concentration induced an atmospheric warming that impacted the lake's thermal structure, increasing the stability of the water column and extending the stratified period by 3 weeks. Epilimnetic temperatures were seen to increase by 2.6°C to 4.2°C, while hypolimnion temperatures increased by 2.2°C. Climate change modified components of the surface energy budget through changes mainly in air temperature, moisture, and cloud cover. During summer, reduced cloud cover resulted in an increase in the annual net solar radiation budget. A larger water vapor deficit at the air-water interface induced a cooling effect in the lake.

  20. Snow covered Alps of France, Italy, and Switzerland

    NASA Image and Video Library

    1973-07-30

    SL3-121-2438 (July-September 1973) --- The Alps of Switzerland, France and Italy are featured in this exceptional photograph taken by a hand-held camera from the Skylab space station during the second manned Skylab mission. Also visible in the out-the-window 70mm Hasselblad view are Lake Geneva, Lake of Lucerne, Rhone River and many other features. The Skylab 3 crewmen, astronauts Alan L. Bean, Owen K. Garriott and Jack R. Lousma completed a 59-day mission with a successful splashdown on Sept. 25, 1973. Photo credit: NASA

  1. Increased Levels of Multiresistant Bacteria and Resistance Genes after Wastewater Treatment and Their Dissemination into Lake Geneva, Switzerland

    PubMed Central

    Czekalski, Nadine; Berthold, Tom; Caucci, Serena; Egli, Andrea; Bürgmann, Helmut

    2012-01-01

    At present, very little is known about the fate and persistence of multiresistant bacteria (MRB) and their resistance genes in natural aquatic environments. Treated, but partly also untreated sewage of the city of Lausanne, Switzerland is discharged into Vidy Bay (Lake Geneva) resulting in high levels of contamination in this part of the lake. In the present work we have studied the prevalence of MRB and resistance genes in the wastewater stream of Lausanne. Samples from hospital and municipal raw sewage, treated effluent from Lausanne’s wastewater treatment plant (WTP) as well as lake water and sediment samples obtained close to the WTP outlet pipe and a remote site close to a drinking water pump were evaluated for the prevalence of MRB. Selected isolates were identified (16S rRNA gene fragment sequencing) and characterized with regards to further resistances, resistance genes, and plasmids. Mostly, studies investigating this issue have relied on cultivation-based approaches. However, the limitations of these tools are well known, in particular for environmental microbial communities, and cultivation-independent molecular tools should be applied in parallel in order to take non-culturable organisms into account. Here we directly quantified the sulfonamide resistance genes sul1 and sul2 from environmental DNA extracts using TaqMan real-time quantitative PCR. Hospital sewage contained the highest load of MRB and antibiotic resistance genes (ARGs). Wastewater treatment reduced the total bacterial load up to 78% but evidence for selection of extremely multiresistant strains and accumulation of resistance genes was observed. Our data clearly indicated pollution of sediments with ARGs in the vicinity of the WTP outlet. The potential of lakes as reservoirs of MRB and potential risks are discussed. PMID:22461783

  2. Monitoring mountain lakes in a changing Alpine cryosphere: the Lago Nero project (Ticino, Switzerland)

    NASA Astrophysics Data System (ADS)

    Scapozza, Cristian; Bruder, Andreas; Domenici, Mattia; Lepori, Fabio; Pera, Sebastian; Pozzoni, Maurizio; Rioggi, Stefano; Colombo, Luca

    2017-04-01

    Mountain lakes and their catchments of the Alpine cryosphere are facing global pressures including climate warming and deposition of atmospheric pollutants. Due to their remoteness, often low buffer capacities and sensitive biotic communities, alpine lake catchments are particularly well suited as sentinels of environmental change. Lago Nero is the object of an intensive survey, aimed at developing predictive models of catchment-wide ecosystem responses to environmental change (Bruder et al. 2016). Lago Nero is located at the head of Val Bavona (Canton Ticino, southern Switzerland), in a southwest-facing catchment, with altitude ranging from 2385 to 2842 m asl. The substrate is dominated by gneissic bedrock with patches of grassy vegetation and shallow soils. The catchment is snow-covered approximately from November to May. For a similar period, the lake is ice-covered. Lago Nero is an oligotrophic, soft-water lake with a surface of approximatively 13 ha and a maximal depth of 73 m. According to the regional model of potential permafrost distribution in the southern Swiss Alps (Scapozza & Mari 2010), the presence of discontinuous permafrost is probable in almost the entire surface of the catchment covered by loose debris. A direct evidence of permafrost occurrence is the presence of a small active/inactive rock glacier in the south-eastern part of the catchment (front altitude: 2560 m asl). Monitoring of the site began in summer 2014, with an initial phase aimed at developing and testing methodologies and at evaluating the suitability of the catchment and the feasibility of the monitoring program. The intensive survey at Lago Nero measures a wide array of ecosystem responses, including runoff quantity and chemistry, catchment soil temperature (also on the rock glacier) and composition of terrestrial vegetation. Sampling frequency depends on the parameter measured, varying from nearly continuous (e.g. runoff and temperature) to five-year intervals (e.g. soil and

  3. Biomarkers and isotopic fingerprinting to track sediment origin and connectivity at Baldegg Lake (Switzerland)

    NASA Astrophysics Data System (ADS)

    Lavrieux, Marlène; Meusburger, Katrin; Birkholz, Axel; Alewell, Christine

    2017-04-01

    Slope destabilization and associated sediment transfer are among the major causes of aquatic ecosystems and surface water quality impairment. Through land uses and agricultural practices, human activities modify the soil erosive risk and the catchment connectivity, becoming a key factor of sediment dynamics. Hence, restoration and management plans of water bodies can only be efficient if the sediment sources and the proportion attributable to different land uses and agricultural practices are identified. Several sediment fingerprinting methods, based on the geochemical (elemental composition), color, magnetic or isotopic (137Cs) sediment properties, are currently in use. However, these tools are not suitable for a land-use based fingerprinting. New organic geochemical approaches are now developed to discriminate source-soil contributions under different land-uses: The compound-specific stable isotopes (CSSI) technique, based on the biomarkers isotopic signature (here, fatty acids δ13C) variability within the plant species, The analysis of highly specific (i.e. source-family- or even source-species-specific) biomarkers assemblages, which use is until now mainly restricted to palaeoenvironmental reconstructions, and which offer also promising prospects for tracing current sediment origin. The approach was applied to reconstruct the spatio-temporal variability of the main sediment sources of Baldegg Lake (Lucern Canton, Switzerland), which suffers from a substantial eutrophication, despite several restoration attempts during the last 40 years. The sediment supplying areas and the exported volumes were identified using CSSI technique and highly specific biomarkers, coupled to a sediment connectivity model. The sediment origin variability was defined through the analysis of suspended river sediments sampled at high flow conditions (short term), and by the analysis of a lake sediment core covering the last 130 years (long term). The results show the utility of

  4. Numerical investigation with a coupled single-column lake-atmosphere model: An application to Western Switzerland

    NASA Astrophysics Data System (ADS)

    Goyette, Stéphane

    2017-04-01

    The potential of a novel atmospheric single-column model (SCM) developed in the framework of the Canadian Regional Climate Model, CRCM, driven by NCEP-NCAR reanalyses is investigated. The approach to solve the model equations and the technique described here may be implemented in any RCM system environment as a model option. The working hypothesis underlying this SCM formulation is that a substantial portion of the variability simulated in the column can be reproduced by processes operating in the vertical dimension and a lesser portion comes from processes operating in the horizontal dimension. This SCM offers interesting prospects as the horizontal and vertical resolution of the RCM is ever increasing. Due to its low computational cost, multiple simulations may be carried out in a short period of time. In this paper, a range of possible results from changing the lower boundary from land to open water surface, and varying model parameters are shown for western Switzerland. The benefit of using Newtonian relaxation, or "nudging", is demonstrated. Results show that air temperature, moisture and windspeed profiles are modified in a coherent manner in the lowest levels. Such changes are consistent with those of the surface vertical sensible, latent heat and momentum fluxes. Compared to atmospheric profiles over land, switching to and open water surface representative of Lake Geneva over the annual cycle of 1990, air temperature is increased by up to 1°C during the autumn and winter seasons, and by 0.5°C during the spring and summer seasons. Specific humidity is increased by up to 0.2 g kg-1 during the autumn and winter seasons and decreased by 0.3 g kg-1 during the spring and summer seasons. The increased windspeed at the surface, often more than 1.5 m s-1, is due to the smaller roughness height. The surface radiation and energy budgets are also modified subsequent to the different partionning of the latent end sensible heat fluxes, but also the solar and thermal

  5. Lake Surface Water Temperature of European Lakes retrieved from AVHRR Data - Time Series and Quality Assessment

    NASA Astrophysics Data System (ADS)

    Wunderle, S.; Lieberherr, G.; Riffler, M.

    2016-12-01

    Data analysis of the recent years showed an increase of lake surface water temperature for many lakes around the world. But due to sparse in-situ measurements, which are often not well documented, only satellite data can provide the needed information of the last decades. The importance of lakes for climate research was also highlighted by the Global Climate Observing System (GCOS) defining lakes as Essential Climate Variables (ECVs). Within the frame of a research project funded by the Swiss National Science Foundation a procedure was developed to retrieve lake surface water temperature with high accuracy based on our archived AVHRR data at the University of Bern, Switzerland. The data archive starts in 1985 and is continuously filled with NOAA-/MetOp-AVHRR data received by our antenna resulting in a time series of more than 30 years (WMO definition of a climate period). The data set covering Europe is also used by other teams for climate related studies resulting in improved pre-processing to guarantee precise calibration and geocoding. The first part of our presentation will be dedicated to the quality of the LSWT retrieval comparing various in-situ measurements from lakes in Switzerland with varying sizes (150km2 - 9km2). The quality of the used split-window approach is sensitive to the derived split-window coefficients. The influence of water vapor, view angle, temporal and spatial validity and day vs. night data will be shown. In addition, some information will be presented about the influence of topography and climatic regions (e.g. Scandinavia vs. Greece) on the quality of the LSWT product. Based on these findings compiling time series for different lakes in Europe will be the focus of the second part of our presentation with details of the applied quality assessment to avoid erroneous signals. Hence, some information is given about hierarchical quality checks which are needed to guarantee a dataset without artefacts. Finally, some results of time series

  6. Diversity and Distribution of Freshwater Amphipod Species in Switzerland (Crustacea: Amphipoda)

    PubMed Central

    Altermatt, Florian; Alther, Roman; Fišer, Cene; Jokela, Jukka; Konec, Marjeta; Küry, Daniel; Mächler, Elvira; Stucki, Pascal; Westram, Anja Marie

    2014-01-01

    Amphipods are key organisms in many freshwater systems and contribute substantially to the diversity and functioning of macroinvertebrate communities. Furthermore, they are commonly used as bioindicators and for ecotoxicological tests. For many areas, however, diversity and distribution of amphipods is inadequately known, which limits their use in ecological and ecotoxicological studies and handicaps conservation initiatives. We studied the diversity and distribution of amphipods in Switzerland (Central Europe), covering four major drainage basins, an altitudinal gradient of>2,500 m, and various habitats (rivers, streams, lakes and groundwater). We provide the first provisional checklist and detailed information on the distribution and diversity of all amphipod species from Switzerland. In total, we found 29 amphipod species. This includes 16 native and 13 non-native species, one of the latter (Orchestia cavimana) reported here for the first time for Switzerland. The diversity is compared to neighboring countries. We specifically discuss species of the genus Niphargus, which are often receiving less attention. We also found evidence of an even higher level of hidden diversity, and the potential occurrence of further cryptic species. This diversity reflects the biogeographic past of Switzerland, and suggests that amphipods are ideally suited to address questions on endemism and adaptive radiations, post-glaciation re-colonization and invasion dynamics as well as biodiversity-ecosystem functioning relationships in aquatic systems. PMID:25354099

  7. A high-resolution historical sediment record of nutrients, trace elements and organochlorines (DDT and PCB) deposition in a drinking water reservoir (Lake Brêt, Switzerland) points at local and regional pollutant sources.

    PubMed

    Thevenon, Florian; de Alencastro, Luiz Felippe; Loizeau, Jean-Luc; Adatte, Thierry; Grandjean, Dominique; Wildi, Walter; Poté, John

    2013-03-01

    The (137)Cs and (210)Pb dating of a 61-cm long sediment core retrieved from a drinking water reservoir (Lake Brêt) located in Switzerland revealed a linear and relatively high sedimentation rate (~1 cm year(-1)) over the last decades. The continuous centimeter scale measurement of physical (porewater and granulometry), organic (C(org), P, N, HI and OI indexes) and mineral (C(min) and lithogenic trace elements) parameters therefore enables reconstructing the environmental history of the lake and anthropogenic pollutant input (trace metals, DDT and PCBs) at high resolution. A major change in the physical properties of the lowermost sediments occurred following the artificial rise of the dam in 1922. After ca. 1940, there was a long-term up-core increase in organic matter deposition attributed to enhance primary production and anoxic bottom water conditions due to excessive nutrient input from a watershed predominantly used for agriculture that also received domestic effluents of two wastewater-treatment plants. This pattern contrasts with the terrigenous element input (Eu, Sc, Mg, Ti, Al, and Fe) which doubled after the rising of the dam but continuously decreased during the last 60 years. By comparison, the trace metals (Cu, Pb and Hg) presented a slight enrichment factor (EF) only during the second part of the 20th century. Although maximum EF Pb (>2) occurred synchronously with the use of leaded gasoline in Switzerland (between ca. 1947 and 1985) the Hg and Cu profiles exhibited a relatively similar trend than Pb during the 20th century, therefore excluding the alkyl-lead added to petrol as the dominant (atmospheric) source of lead input to Lake Brêt. Conversely, the Cu profile that did not follow the decrease registered in Pb and Hg during the last 10 years, suggests an additional source of Cu probably linked to the impact of agricultural activities in the area. In absence of heavy industries in the catchment, the atmospheric deposition of DDT and PCBs via

  8. Joint Geodetic and Seismic Analysis of the effects of Englacial and Subglacial Hydraulics on Surface Crevassing near a Seasonal, Glacier-Dammed Lake on Gornergletscher, Switzerland

    NASA Astrophysics Data System (ADS)

    Garcia, L.; Luttrell, K. M.; Kilb, D. L.; Walter, F.

    2017-12-01

    Glacial outburst floods are difficult to predict and threaten human life and property near glaciated regions. These events are characterized by rapid draining of glacier-dammed lakes via the sub/englacial hydraulic network to the proglacial stream. The glacier-dammed lake on Gornergletscher in Switzerland, which fills and drains each summer, provides an opportunity to study this hazard. For three drainages (2004, 2006, and 2007), we track icequakes (IQ) and on-ice GPS movement. Our seasonal seismic networks had 8 - 24 three component stations and apertures of about 300 - 400 m on the glacier surface. The seasonal GPS arrays contained 4 - 8 GPS antennae on the glacier surface. Using Rayleigh wave coherence surface IQ location, we located 2924, 7822 and 3782 IQs, in 2004, 2006 and 2007, respectively. The GPS data were smoothed using a nonparametric protocol, with average station velocities of 10 - 90 mm/day. In 2006, strains were calculated using five stations within 500 m of the lake, co-located with the seismic network. IQ productivity increased substantially during lake drainage only in 2004, which was the only year when the lake drainage was rapid ( 6 days) and primarily subglacial. In 2006, there was no obvious increase in GPS speeds with slow ( 21 days), supraglacial lake drainage. However, when drainage was subglacial as in 2004 and 2007 (sub/englacial over 11 days), GPS speed increased up to 160%. This speed increase is evidence for basal sliding induced by subglacial drainage. In general, we find that when the strain increase on the principle extension axis aligns with the crevasse opening direction, IQ are more prolific. We also observe a diurnal signal in both IQ occurrence and surface strain, with peak strain occurring in the mid- to late-afternoon (15:00 - 19:00 local) across the study area in 2006. We interpret this time-shift in strain and spatiotemporal dependence of IQs to be caused by diurnal variations in melt-induced sliding. Our analysis sheds

  9. Total and methyl-mercury seasonal particulate fluxes in the water column of a large lake (Lake Geneva, Switzerland).

    PubMed

    Díez, Elena Gascón; Graham, Neil D; Loizeau, Jean-Luc

    2018-05-16

    Concentrations and fluxes of total and methylmercury were determined in surface sediments and associated with settling particles at two sites in Lake Geneva to evaluate the sources and dynamics of this toxic contaminant. Total mercury concentrations measured in settling particles were different throughout the seasons and were greatly influenced by the Rhone River particulate inputs. Total mercury concentrations closer to shore (NG2) ranged between 0.073 ± 0.001 and 0.27 ± 0.01 μg/g, and between 0.038 ± 0.001 and 0.214 ± 0.008 μg/g at a site deeper in the lake (NG3). Total mercury fluxes ranged between 0.144 ± 0.002 and 3.0 ± 0.1 μg/m 2 /day at NG2, and between 0.102 ± 0.008 and 1.32 ± 0.08 μg/m 2 /day at NG3. Combined results of concentrations and fluxes showed that total mercury concentrations in settling particles are related to the season and particle inputs from the Rhone River. Despite an observed decrease in total mercury fluxes from the coastal zone towards the open lake, NG3 (~ 3 km from the shoreline) was still affected by the coastal boundary, as compared to distal sites at the center of the lake. Thus, sediment focusing is not efficient enough to redistribute contaminant inputs originating from the coastal zones, to the lake center. Methylmercury concentrations in settling particles largely exceeded the concentrations found in sediments, and their fluxes did not show significant differences with relation to the distance from shore. The methylmercury found associated with settling particles would be related to the lake's internal production rather than the effect of transport from sediment resuspension.

  10. Rhone River Valley & Lower Lake Geneva, Switzerland as seen from STS-60

    NASA Image and Video Library

    1994-02-09

    STS060-90-007 (3-11 Feb 1994) --- Parts of the Swiss Cantons of Vaud and Valois and the French province of Chablais are shown. These mountains were created in the last great mountain-building episode in Europe around 50 million years ago. They have been reshaped by glaciers during the Pleistocene. The glaciers created the wide valley of the Rhone River by scouring a pre-existing stream. The fertile Swiss Plateau runs northwest from the shore of Lake Geneva and is visible in the upper right. The Franco-Swiss border is located in the center of the lake and follows a mountain divide east of the Rhone Valley. According to NASA geologists eutrofication is a problem in Lake Geneva. In 1971 a Swiss Commission was formed to try to slow the problem. Strong discharge laws were enacted, but they are hard to enforce due to the multi-national and multi-organizational parties contributing to the problem.

  11. Lake sediment records as earthquake catalogues: A compilation from Swiss lakes - Limitations and possibilities

    NASA Astrophysics Data System (ADS)

    Kremer, Katrina; Reusch, Anna; Wirth, Stefanie B.; Anselmetti, Flavio S.; Girardclos, Stéphanie; Strasser, Michael

    2016-04-01

    Intraplate settings are characterized by low deformation rates and recurrence intervals of strong earthquakes that often exceed the time span covered by instrumental records. Switzerland, as an example for such settings, shows a low instrumentally recorded seismicity, in contrast to strong earthquakes (e.g. 1356 Basel earthquake, Mw=6.6 and 1601 Unterwalden earthquake, Mw=5.9) mentioned in the historical archives. As such long recurrence rates do not allow for instrumental identification of earthquake sources of these strong events, and as intense geomorphologic alterations prevent preservation of surface expressions of faults, the knowledge of active faults is very limited. Lake sediments are sensitive to seismic shaking and thus, can be used to extend the regional earthquake catalogue if the sedimentary deposits or deformation structures can be linked to an earthquake. Single lake records allow estimating local intensities of shaking while multiple lake records can furthermore be used to compare temporal and spatial distribution of earthquakes. In this study, we compile a large dataset of dated sedimentary event deposits recorded in Swiss lakes available from peer-reviewed publications and unpublished master theses. We combine these data in order to detect large prehistoric regional earthquake events or periods of intense shaking that might have affected multiple lake settings. In a second step, using empirical seismic attenuation equations, we test if lake records can be used to reconstruct magnitudes and epicentres of identified earthquakes.

  12. Past and future warming of a deep European lake (Lake Lugano): What are the climatic drivers?

    USGS Publications Warehouse

    Lepori, Fabio; Roberts, James J.

    2015-01-01

    We used four decades (1972–2013) of temperature data from Lake Lugano, Switzerland and Italy, to address the hypotheses that: [i] the lake has been warming; [ii] part of the warming reflects global trends and is independent from climatic oscillations and [iii] the lake will continue to warm until the end of the 21st century. During the time spanned by our data, the surface waters of the lake (0–5 m) warmed at rates of 0.2–0.9 °C per decade, depending on season. The temperature of the deep waters (50-m bottom) displayed a rising trend in a meromictic basin of the lake and a sawtooth pattern in the other basin, which is holomictic. Long-term variation in surfacewater temperature correlated to global warming and multidecadal variation in two climatic oscillations, the Atlantic Multidecadal Oscillation (AMO) and the East Atlantic Pattern (EA).However, we did not detect an influence of the EA on the lake's temperature (as separate from the effect of global warming). Moreover, the effect of the AMO, estimated to a maximum of +1 °C, was not sufficient to explain the observed temperature increase (+2–3 °C in summer). Based on regional climate projections, we predicted that the lake will continue to warm at least until the end of the 21st century. Our results strongly suggest that the warming of Lake Lugano is tied to globalclimate change. To sustain current ecosystem conditions in Lake Lugano, we suggest that manage- ment plans that curtail eutrophication and (or) mitigation of global warming be pursued.

  13. Reconstruction of multistage massive rock slope failure: Polymethodical approach in Lake Oeschinen (CH)

    NASA Astrophysics Data System (ADS)

    Knapp, Sibylle; Gilli, Adrian; Anselmetti, Flavio S.; Hajdas, Irka

    2016-04-01

    Lateglacial and Holocene rock-slope failures occur often as multistage failures where paraglacial adjustment and stress adaptation are hypothesised to control stages of detachment. However, we have only limited datasets to reconstruct detailed stages of large multistage rock-slope failures, and still aim at improving our models in terms of geohazard assessment. Here we use lake sediments, well-established for paleoclimate and paleoseismological reconstruction, with a focus on the reconstruction of rock-slope failures. We present a unique inventory from Lake Oeschinen (Bernese Alps, Switzerland) covering about 2.4 kyrs of rock-slope failure history. The lake sediments have been analysed using sediment-core analysis, radiocarbon dating and seismic-to-core and core-to-core correlations, and these were linked to historical and meteorological records. The results imply that the lake is significantly younger than the ~9 kyrs old Kandersteg rock avalanche (Tinner et al., 2005) and shows multiple rock-slope failures, two of which could be C14-dated. Several events detached from the same area potentially initiated by prehistoric earthquakes (Monecke et al., 2006) and later from stress relaxation processes. The data imply unexpected short recurrence rates that can be related to certain detachment scarps and also help to understand the generation of a historical lake-outburst flood. Here we show how polymethodical analysis of lake sediments can help to decipher massive multistage rock-slope failure. References Monecke, K., Anselmetti, F.S., Becker, A., Schnellmann, M., Sturm, M., Giardini, D., 2006. Earthquake-induced deformation structures in lake deposits: A Late Pleistocene to Holocene paleoseismic record for Central Switzerland. Eclogae Geologicae Helvetiae, 99(3), 343-362. Tinner, W., Kaltenrieder, P., Soom, M., Zwahlen, P., Schmidhalter, M., Boschetti, A., Schlüchter, C., 2005. Der nacheiszeitliche Bergsturz im Kandertal (Schweiz): Alter und Auswirkungen auf die

  14. Development of a 3D VHR seismic reflection system for lacustrine settings - a case study in Lake Geneva, Switzerland

    NASA Astrophysics Data System (ADS)

    Scheidhauer, M.; Dupuy, D.; Marillier, F.; Beres, M.

    2003-04-01

    For better understanding of geologic processes in complex lacustrine settings, detailed information on geologic features is required. In many cases, the 3D seismic method may be the only appropriate approach. The aim of this work is to develop an efficient very high-resolution 3D seismic reflection system for lake studies. In Lake Geneva, Switzerland, near the city of Lausanne, past high-resolution investigations revealed a complex fault zone, which was subsequently chosen for testing our new system of three 24-channel streamers and integrated differential GPS (dGPS) positioning. A survey, carried out in 9 days in August 2001, covered an area of 1500^om x 675^om and comprised 180 CMP lines sailed perpendicular to the fault strike always updip, since otherwise the asymmetric system would result in different stacks for opposite directions. Accurate navigation and shot spacing of 5^om is achieved with a specially developed navigation and shot-triggering software that uses differential GPS onboard and a reference base close to the lake shore. Hydrophone positions could be accurately (<^o0.5^om) calculated with the aid of three additional dGPS antennas mounted on rafts attached to the streamer tails. Towed at a distance of only 75^om behind the vessel, they allowed determination of possible feathering due to cross-line currents or small course variations. The multi-streamer system uses two retractable booms deployed on each side of the boat and rest on floats. They separate the two outer streamers from the one in the center by a distance of 7.5^om. Combined with a receiver spacing of 2.5^om, the bin dimension of the 3D data becomes 3.75^om in cross-line and 1.25^om in inline direction. Potential aliasing problems from steep reflectors up to 30^o within the fault zone motivated the use of a 15/15 cu. in. double-chamber bubble-canceling Mini G.I. air gun (operated at 80^obars and 1^om depth). Although its frequencies do not exceed 650^o Hz, it combines a penetration of

  15. A Multiscale Surface Water Temperature Data Acquisition Platform: Tests on Lake Geneva, Switzerland

    NASA Astrophysics Data System (ADS)

    Barry, D. A.; Irani Rahaghi, A.; Lemmin, U.; Riffler, M.; Wunderle, S.

    2015-12-01

    An improved understanding of surface transport processes is necessary to predict sediment, pollutant and phytoplankton patterns in large lakes. Lake surface water temperature (LSWT), which varies in space and time, reflects meteorological and climatological forcing more than any other physical lake parameter. There are different data sources for LSWT mapping, including remote sensing and in situ measurements. Satellite data can be suitable for detecting large-scale thermal patterns, but not meso- or small scale processes. Lake surface thermography, investigated in this study, has finer resolution compared to satellite images. Thermography at the meso-scale provides the ability to ground-truth satellite imagery over scales of one to several satellite image pixels. On the other hand, thermography data can be used as a control in schemes to upscale local measurements that account for surface energy fluxes and the vertical energy budget. Independently, since such data can be collected at high frequency, they can be also useful in capturing changes in the surface signatures of meso-scale eddies and thus to quantify mixing processes. In the present study, we report results from a Balloon Launched Imaging and Monitoring Platform (BLIMP), which was developed in order to measure the LSWT at meso-scale. The BLIMP consists of a small balloon that is tethered to a boat and equipped with thermal and RGB cameras, as well as other instrumentation for location and communication. Several deployments were carried out on Lake Geneva. In a typical deployment, the BLIMP is towed by a boat, and collects high frequency data from different heights (i.e., spatial resolutions) and locations. Simultaneous ground-truthing of the BLIMP data is achieved using an autonomous craft that collects a variety of data, including in situ surface/near surface temperatures, radiation and meteorological data in the area covered by the BLIMP images. With suitable scaling, our results show good consistency

  16. Lake Ice Detection in Low-Resolution Optical Satellite Images

    NASA Astrophysics Data System (ADS)

    Tom, M.; Kälin, U.; Sütterlin, M.; Baltsavias, E.; Schindler, K.

    2018-05-01

    Monitoring and analyzing the (decreasing) trends in lake freezing provides important information for climate research. Multi-temporal satellite images are a natural data source to survey ice on lakes. In this paper, we describe a method for lake ice monitoring, which uses low spatial resolution (250 m-1000 m) satellite images to determine whether a lake is frozen or not. We report results on four selected lakes in Switzerland: Sihl, Sils, Silvaplana and St. Moritz. These lakes have different properties regarding area, altitude, surrounding topography and freezing frequency, describing cases of medium to high difficulty. Digitized Open Street Map (OSM) lake outlines are back-projected on to the image space after generalization. As a pre-processing step, the absolute geolocation error of the lake outlines is corrected by matching the projected outlines to the images. We define the lake ice detection as a two-class (frozen, non-frozen) semantic segmentation problem. Several spectral channels of the multi-spectral satellite data are used, both reflective and emissive (thermal). Only the cloud-free (clean) pixels which lie completely inside the lake are analyzed. The most useful channels to solve the problem are selected with xgboost and visual analysis of histograms of reference data, while the classification is done with non-linear support vector machine (SVM). We show experimentally that this straight-forward approach works well with both MODIS and VIIRS satellite imagery. Moreover, we show that the algorithm produces consistent results when tested on data from multiple winters.

  17. Use of Isotope Ratio Mass Spectrometry (IRMS) Determination ((18)O/(16)O) to Assess the Local Origin of Fish and Asparagus in Western Switzerland.

    PubMed

    Rossier, Joël S; Maury, Valérie; de Voogd, Blaise; Pfammatter, Elmar

    2014-10-01

    Here we present the use of isotope ratio mass spectrometry (IRMS) for the detection of mislabelling of food produced in Switzerland. The system is based on the analysis of the oxygen isotope distribution in water (δ(18)O). Depending on the location on the earth, lake or groundwater has a specific isotopic distribution, which can serve as a fingerprint in order to verify whether a product has grown by means of the corresponding water. This report presents specifically the IRMS technique and the results obtained in the origin detection of fish grown in selected Swiss lakes as well as asparagus grown in Valais ground. Strengths and limitations of the method are presented for both cited products; on one hand, the technique is relatively universal for any product which contains significant water but on the other hand, it necessitates a rather heavy workload to build up a database of water δ(18)O values of products of different origins. This analytical tool is part of the concept of combating fraud currently in use in Switzerland.

  18. Hazard Map in Huaraz-Peru due to a Glacial Lake Outburst Flood from Palcacocha Lake

    NASA Astrophysics Data System (ADS)

    Somos-Valenzuela, M. A.; Chisolm, R. E.; McKinney, D. C.; Rivas, D.

    2013-12-01

    the hazard we implement a combination of criteria from different countries (Switzerland, Austria and the U.S.), these criteria consider that the level of flooding hazard in an urban area is a function of the maximum velocity and inundation depth. We have found that 30,000 people, approximately one third of the city of Huaraz, could be affected by a GLOF from Lake Palcacocha.

  19. Migration of 137Cs in tributaries, lake water and sediment of Lago Maggiore (Italy, Switzerland) - analysis and comparison with Lago di Lugano and other lakes.

    PubMed

    Putyrskaya, Victoria; Klemt, Eckehard; Röllin, Stefan

    2009-01-01

    This paper describes the behaviour of 137Cs in Lago Maggiore and other pre-alpine lakes as a consequence of atmospheric nuclear weapons testing fallout and the fallout from the nuclear accident in Chernobyl. It presents data on the 137Cs distribution in tributaries, lake water, bottom sediments and reveals the role of (137)Cs as a marker of the sedimentation processes. The run-off of 137Cs from the watershed to the lake is described with a simple compartment model. Measurements of the activity concentration of (137)Cs in sediments are compared with the output of a model (diffusion-convection type) which describes the input of 137Cs into and its vertical distribution within the sediment. Varying sedimentation rates (0.05-0.90g(cm2y)(-1)) in Lago Maggiore are compared with data of other authors. Sedimentation rates and total distribution coefficients (of about 10(5) Lkg(-1)) in Lago Maggiore are discussed and compared with those of Lago di Lugano, Lake Constance, and Lake Vorsee.

  20. [Decompression problems in diving in mountain lakes].

    PubMed

    Bühlmann, A A

    1989-08-01

    The relationship between tolerated high-pressure tissue nitrogen and ambient pressure is practically linear. The tolerated nitrogen high pressure decreases at altitude, as the ambient pressure is lower. Additionally, tissues with short nitrogen half-times have a higher tolerance than tissues which retain nitrogen for longer duration. For the purpose of determining safe decompression routines, the human body can be regarded as consisting of 16 compartments with half-times from 4 to 635 minutes for nitrogen. The coefficients for calculation of the tolerated nitrogen-high pressure in the tissues can be deduced directly from the half-times for nitrogen. We show as application the results of 573 simulated air dives in the pressure-chamber and 544 real dives in mountain lakes in Switzerland (1400-2600 m above sea level) and in Lake Titicaca (3800 m above sea level). They are in accordance with the computed limits of tolerance.

  1. The Tambora effect on the hydrology of Switzerland in 1816/1817

    NASA Astrophysics Data System (ADS)

    Rössler, Ole; Brönnimann, Stefan

    2017-04-01

    The eruption of the volcano Tambora in 1815 caused what is literally called "the year without summer" in 1816 in Switzerland, resulting among others in extensive harvest losses. Furthermore, it has been reported that the snow was significantly present throughout the year. Hence, in the following winter fresh snow piled on top what was left from the last year, and an unusually snowy spring 1817 further increased snow heights. It has been argued that the spring floods at the Lake Constance (highest reported lake level) and at Basel are a result from the assumed massive snow melt. We here present an approach and first results of a study that tries to reconstruct this extraordinary event. Based on historical meteorological measurements at three locations, an analogue method was applied that reconstructs daily precipitation and temperature for the years 1816 and 1817 for the Rhine river basin up to Basel. Analogues were sampled from observation based gridded datasets of precipitation and temperature from last 50 years in Switzerland. As the Rhine catchment to Basel covers also parts of Germany and Austria, the Swiss gridded dataset was extended via analogues date from the E-OBS dataset. This meteorological input drove the hydrological model WaSiM-ETH, both for the reference period 1981-2009 and the Tambora scenario period 1816/1817. First, the hydrological model was calibrated (1991-1999) and validated (1981-2009) against discharge from the river Rhine at Basel, CH, using the same gridded data sets for temperature and precipitation. For the sake of simplicity in first place, land use and river regulations are kept as they are today. We found that the general river regime is reproducible in 1816 and 1817. So is the reported snow development. Hence, we argue that the general set up is feasible and the effect of the Tambora eruption on the average hydrological conditions can be estimated. However, the flood peaks during the years 1816 and 1817 are underestimated if present

  2. Small-scale and mesoscale lake surface water temperature structure: Thermography and in situ measurements from Lake Geneva, Switzerland

    NASA Astrophysics Data System (ADS)

    Irani Rahaghi, Abolfazl; Lemmin, Ulrich; Bouffard, Damien; Riffler, Michael; Wunderle, Stefan; Barry, Andrew

    2017-04-01

    Lake surface water temperature (LSWT), which varies spatially and temporarily, reflects meteorological and climatological forcing more than any other physical lake parameter. There are different data sources for LSWT mapping, including remote sensing and in situ measurements. Depending on cloud cover, satellite data can depict large-scale thermal patterns, but not the meso- or small-scale processes. Meso-scale thermography allows complementing (and hence ground-truth) satellite imagery at the sub-pixel scale. A Balloon Launched Imaging and Monitoring Platform (BLIMP) was used to measure the LSWT at the meso-scale. The BLIMP consists of a small balloon tethered to a boat and is equipped with thermal and RGB cameras, as well as other instrumentation for geo-location and communication. A feature matching-based algorithm was implemented to create composite thermal images. Simultaneous ground-truthing of the BLIMP data were achieved using an autonomous craft measuring among other in situ surface/near surface temperatures, radiation and meteorological data. Latent and sensible surface heat fluxes were calculated using the bulk parameterization algorithm based on similarity theory. Results are presented for the day-time stratified low wind speed (up to 3 ms-1) conditions over Lake Geneva for two field campaigns, each of 6 h on 18 March and 19 July 2016. The meso-scale temperature field ( 1-m pixel resolution) had a range and standard deviation of 2.4°C and 0.3°C, respectively, over a 1-km2 area (typical satellite pixel size). Interestingly, at the sub-pixel scale, various temporal and spatial thermal structures are evident - an obvious example being streaks in the along-wind direction during March, which we hypothesize are caused by the steady 3 h wind condition. The results also show that the spatial variability of the estimated total heat flux is due to the corresponding variability of the longwave cooling from the water surface and the latent heat flux.

  3. Release of PCBs from Silvretta glacier (Switzerland) investigated in lake sediments and meltwater.

    PubMed

    Pavlova, P A; Zennegg, M; Anselmetti, F S; Schmid, P; Bogdal, C; Steinlin, C; Jäggi, M; Schwikowski, M

    2016-06-01

    This study is part of our investigations about the release of persistent organic pollutants from melting Alpine glaciers and the relevance of the glaciers as secondary sources of legacy pollutants. Here, we studied the melt-related release of polychlorinated biphenyls (PCBs) in proglacial lakes and glacier streams of the catchment of the Silvretta glacier, located in the Swiss Alps. To explore a spatial and temporal distribution of chemicals in glacier melt, we combined two approaches: (1) analysing a sediment record as an archive of past remobilization and (2) passive water sampling to capture the current release of PCBs during melt period. In addition, we determined PCBs in a non-glacier-fed stream as a reference for the background pollutant level in the area. The PCBs in the sediment core from the Silvretta lake generally complied with trends of PCB emissions into the environment. Elevated concentrations during the most recent ten years, comparable in level with times of the highest atmospheric input, were attributed to accelerated melting of the glacier. This interpretation is supported by the detected PCB fractionation pattern towards heavier, less volatile congeners, and by increased activity concentrations of the radioactive tracer (137)Cs in this part of the sediment core. In contrast, PCB concentrations were not elevated in the stream water, since no significant difference between pollutant concentrations in the glacier-fed and the non-glacier-fed streams was detected. In stream water, no current decrease of the PCBs with distance from the glacier was observed. Thus, according to our data, an influence of PCBs release due to accelerated glacier melt was only detected in the proglacial lake, but not in the other compartments of the Silvretta catchment.

  4. Lake Biel Holocene sediment record before and after the Aare river deviation (1878 AD)

    NASA Astrophysics Data System (ADS)

    Jeannet, Alice; Corella, Juan Pablo; Kremer, Katrina; Girardclos, Stéphanie

    2014-05-01

    Lake sediments are excellent archives of environmental and climate changes as well as human impact on lake- and river-systems. Lake Biel is a medium-sized peri-alpine lake in Switzerland, with a maximum depth of 74 m, and lies at an altitude of 429 m a.s.l. Lake Biel, which formed during the Pleistocene by glacial erosion, is part of the Aare river system. Our study focuses on the south-west part of the lake basin where the lake sedimentation was originally (i.e. naturally) mainly controlled by autochthonous sedimentation. This area is currently under a strong influence of water and sediment input from this river catchment since the Aare river deviation through the Hagneck canal in 1878. A 10.05 m long composite sediment sequence, cored from a 52 m water depth in September 2011, was built from two long cores retrieved with the ETH Zurich/Eawag Uwitec system. A radiocarbon age model indicates that the retrieved sedimentary sequence spans the last 7500 years. The upper sediments were correlated to previous short core radionuclide stratigraphy for the 1.5 m upper part (Thevenon et al., 2013). Magnetic susceptibility and density were measured by Geotek MultiSensor Core Logger at 0.5 cm resolution. Granulometry was measured with a CILAS grain sizer every 10 cm, and X-ray fluorescence (XRF) was carried out using an Avaatech core scanner at 1-cm resolution. This technique provides semi-quantitative information of the sediment elemental composition and shows how runoff and river input (Ti, Al, Si) or redox conditions (Fe/Mn) vary through time. Lake Biel sediment record suggests marked environmental changes with runoff decrease linked to climate and vegetation change during Atlantic chronobiozone, as well as a complex climate-human impact during the 'La Tène' and Roman cultural times. The most prominent recorded feature is the 10-times increase of sediment rate that occurred after the Aare river deviation through the Hagneck canal into Lake Biel in 1878. This artificial

  5. Effects of climate change on deep-water oxygen and winter mixing in a deep lake (Lake Geneva)

    NASA Astrophysics Data System (ADS)

    Schwefel, Robert; Alfred, Wüest; Damien, Bouffard

    2016-04-01

    Oxygen is the most important dissolved gas for lake ecosystems. Because low oxygen concentrations are an ongoing problem in many parts of the oceans and numerous lakes, oxygen depletion processes have been intensively studied over the last decades and were mainly attributed to high nutrient loads. Recently, climate-induced changes in stratification and mixing behavior were recognized as additional thread to hypolimnetic oxygen budgets in lakes and reservoirs [Matzinger et al., 2007; Zhang et al., 2015]. Observational data of Lake Geneva, a deep perialpine lake situated between France and Switzerland showed no decreasing trend in hypoxia over the last 43 years, despite an impressive reduction in nutrient input during this period. Instead, hypoxic conditions were predominantly controlled by deep mixing end of winter and in turn by winter temperatures. To test the sensitivity of Lake Geneva on future climate change and changes in water transparency, we simulated the hydrodynamics and temperature of Lake Geneva under varying conditions for atmospheric temperature and water clarity performed with the one-dimensional model SIMSTRAT [Goudsmit, 2002]. The results show, that the stratification in lakes is only weakly affected by changes in light absorption due to varying water quality. For conditions expected for the end of the century, a decrease in the annual mean deep convective mixing of up to 45 m is predicted. Also complete mixing events over the whole lake are less likely to occur. A change in the hypolimnetic oxygen concentration of up to 20% can thus be expected in the future. These results show, that changes in deep mixing have an equally strong impact as eutrophication on the deep-water oxygen development of oligomictic lakes and have to be considered in the prediction of the future development of lakes. References: Goudsmit, G. H., H. Burchard, F. Peeters, and A. Wüest (2002), Application of k-ɛ turbulence models to enclosed basins: The role of internal

  6. Diversification of Tertiary Education in Switzerland.

    ERIC Educational Resources Information Center

    Crausaz, Roselyne

    The structure of Switzerland's educational system is described including the types of secondary schools and/or courses and the system of tertiary education. Fields of study, types of institutions, and characteristics of tertiary education in Switzerland are discussed. The chapter on students covers admission procedures, trends in enrollment,…

  7. Origin and spatial-temporal distribution of faecal bacteria in a bay of Lake Geneva, Switzerland.

    PubMed

    Poté, John; Goldscheider, Nico; Haller, Laurence; Zopfi, Jakob; Khajehnouri, Fereidoun; Wildi, Walter

    2009-07-01

    The origin and distribution of microbial contamination in Lake Geneva's most polluted bay were assessed using faecal indicator bacteria (FIB). The lake is used as drinking water, for recreation and fishing. During 1 year, water samples were taken at 23 points in the bay and three contamination sources: a wastewater treatment plant (WWTP), a river and a storm water outlet. Analyses included Escherichia coli, enterococci (ENT), total coliforms (TC), and heterotrophic plate counts (HPC). E. coli input flux rates from the WWTP can reach 2.5 x 10(10) CFU/s; those from the river are one to three orders of magnitude lower. Different pathogenic Salmonella serotypes were identified in water from these sources. FIB levels in the bay are highly variable. Results demonstrate that (1) the WWTP outlet at 30 m depth impacts near-surface water quality during holomixis in winter; (2) when the lake is stratified, the effluent water is generally trapped below the thermocline; (3) during major floods, upwelling across the thermocline may occur; (4) the river permanently contributes to contamination, mainly near the river mouth and during floods, when the storm water outlet contributes additionally; (5) the lowest FIB levels in the near-surface water occur during low-flow periods in the bathing season.

  8. Forecasting the evolution in the mixing regime of a deep subalpine lake under climate change scenarios through numerical modelling (Lake Maggiore, Northern Italy/Southern Switzerland)

    NASA Astrophysics Data System (ADS)

    Fenocchi, Andrea; Rogora, Michela; Sibilla, Stefano; Ciampittiello, Marzia; Dresti, Claudia

    2018-01-01

    The impact of air temperature rise is eminent for the large deep lakes in the Italian subalpine district, climate change being caused there by both natural phenomena and anthropogenic greenhouse-gases (GHG) emissions. These oligomictic lakes are experiencing a decrease in the frequency of winter full turnover and an intensification of stability. As a result, hypolimnetic oxygen concentrations are decreasing and nutrients are accumulating in bottom water, with effects on the whole ecosystem functioning. Forecasting the future evolution of the mixing pattern is relevant to assess if a reduction in GHG releases would be able to revert such processes. The study focuses on Lake Maggiore, for which the thermal structure evolution under climate change in the 2016-2085 period was assessed through numerical simulations, performed with the General Lake Model (GLM). Different prospects of regional air temperature rise were considered, given by the Swiss Climate Change Scenarios CH2011. Multiple realisations were performed for each scenario to obtain robust statistical predictions, adopting random series of meteorological data produced with the Vector-Autoregressive Weather Generator (VG). Results show that a reversion in the increasing thermal stability would be possible only if global GHG emissions started to be reduced by 2020, allowing an equilibrium mixing regime to be restored by the end of the twenty-first century. Otherwise, persistent lack of complete-mixing, severe water warming and extensive effects on water quality are to be expected for the centuries to come. These projections can be extended to the other lakes in the subalpine district.

  9. High-resolution seismic stratigraphy of an Holocene lacustrine delta in western Lake Geneva (Switzerland)

    USGS Publications Warehouse

    Baster, I.; Girardclos, S.; Pugin, A.; Wildi, W.

    2003-01-01

    A high-resolution seismic survey was conducted in western Lake Geneva on a small delta formed by the Promenthouse, the Asse and the Boiron rivers. This dataset provides information on changes in the geometry and sedimentation patterns of this delta from Late-glacial to Present. The geometry of the deposits of the lacustrine delta has been mapped using 300-m spaced grid lines acquired with a 12 kHz Echosounder subbottom profiler. A complete three dimensional image of the sediment architecture was reconstructed through seismic stratigraphic analysis. Six different delta lobes have been recognized in the prodelta area. Depositional centers and lateral extension of the delta have changed through time, indicating migration and fluctuation of river input as well as changes in lake currents and wind regime from the time of glacier retreat to the Present. The delta slope is characterized by a high instability causing stumps developing and by the accumulation of biogenic gas that prevents seismic penetration.

  10. The isotopic imprint of fixed nitrogen elimination in the redox transition zone of Lake Lugano, Switzerland

    NASA Astrophysics Data System (ADS)

    Wenk, Christine; Blees, Jan; Niemann, Helge; Zopfi, Jakob; Schubert, Carsten J.; Veronesi, Mauro; Simona, Marco; Koba, Keisuke; Lehmann, Moritz F.

    2010-05-01

    Nitrogen (N) loading in lakes from natural and anthropogenic sources is partially mitigated by microbially mediated processes that take place in redox transition zones (RTZ) in the water column and in sediments. However, the role of lakes as a terrestrial sink of fixed N is still poorly constrained. Furthermore, modes of suboxic N2 (and N2O) production other than canonical denitrification (e.g. anaerobic ammonium oxidation, or anammox) have barely been investigated in lakes, and the microbial communities involved in N transformations in lacustrine RTZ are mostly unknown. The isotopic composition of dissolved nitrogen species can serve as a reliable indicator of N-transformations in aquatic environments. However, the successful application of N (and O) isotope measurements in natural systems requires a solid understanding of the various N-transformation-specific isotope effects. The deep, south-alpine Lake Lugano, with a permanent chemocline in its North Basin, is an excellent model system for a biogeochemically dynamic lake, in which to study N isotope ratio variations associated with fixed N elimination and regeneration processes. We present the first comprehensive dataset of hydrochemical parameters (including N2/Ar and dissolved N2O concentrations), natural abundance stable isotope ratios of dissolved inorganic nitrogen (DIN) compounds (nitrate, nitrite, ammonium, dinitrogen, nitrous oxide), and the isotopomeric composition of water column N2O for the North Basin of Lake Lugano. Isotopic data will be integrated with molecular microbiological phylogenetic analyses and results from incubation experiments with 15N-labeled N-substrates. Strong gradients in DIN concentrations, as well as in the N and O isotope (and isotopomeric) compositions of nitrate and N2O towards the redox-transition zone indicate nitrate reduction, occurring with a high community N-fractionation. The site preference of N2O isotopomers above the chemocline indicates that the N2O is not only

  11. Seasonal Dynamics of Glyphosate and AMPA in Lake Greifensee: Rapid Microbial Degradation in the Epilimnion During Summer.

    PubMed

    Huntscha, Sebastian; Stravs, Michael A; Bühlmann, Andreas; Ahrens, Christian H; Frey, Jürg E; Pomati, Francesco; Hollender, Juliane; Buerge, Ignaz J; Balmer, Marianne E; Poiger, Thomas

    2018-04-17

    Occurrence and fate of glyphosate, a widely used herbicide, and its main metabolite AMPA was investigated in Lake Greifensee, Switzerland. Monthly vertical concentration profiles in the lake showed an increase of glyphosate concentrations in the epilimnion from 15 ng/L in March to 145 ng/L in July, followed by a sharp decline to <5 ng/L in August. A similar pattern was observed for AMPA. Concentrations of glyphosate and AMPA in the two main tributaries generally were much higher than in the lake. Simulations using a numerical lake model indicated that a substantial amount of glyphosate and AMPA dissipated in the epilimnion, mainly in July and August, with half-lives of only ≈2-4 days which is ≫100 times faster than in the preceding months. Fast dissipation coincided with high water temperatures and phytoplankton densities, and low phosphate concentrations. This indicates that glyphosate might have been used as an alternative phosphorus source by bacterio- and phytoplankton. Metagenomic analysis of lake water revealed the presence of organisms known to be capable of degrading glyphosate and AMPA.

  12. Dental tourism from Switzerland to Germany.

    PubMed

    Gheorghe, Raluca; Zürcher, Andrea; Filippi, Andreas

    In recent years the topic of dental tourism has increasingly come into focus of dentists and patients. In the present study an attempt was made to find out, why patients from a restricted region travel to Germany for dental care. In five German dental clinics located in the border area between Switzerland and Germany, 272 women and 236 men ranging in age from 5 to 94 years, who had undergone at least one dental treatment in Germany, were questioned concerning the reasons for their visits. The interviews took place within a period of 6 months and relied on a questionnaire to collect data regarding sociodemographic features and patient behavior. In comparison to residents of Germany, patients residing in Switzerland took on considerably longer travel distances for the dental visit, in some cases more than 50km (9.7%). For patients residing in Switzerland the technical equipment of the practice was more important (p<0.001), whereas for residents of Germany the cost-effective treatment was decisive (p<0.05). Almost all patients residing in Switzerland (95.6%) confirmed that dental treatments in Germany were cheaper and that additional family members also came to Germany for dental care (65.0%).

  13. Post-glacial rock avalanches in the Obersee Valley, Glarner Alps, Switzerland

    NASA Astrophysics Data System (ADS)

    Nagelisen, Jan; Moore, Jeffrey R.; Vockenhuber, Christoph; Ivy-Ochs, Susan

    2015-06-01

    The geological record of prehistoric rock avalanches provides invaluable data for assessing the hazard posed by these rare but destructive mass movements. Here we investigate two large rock avalanches in the Obersee valley of the Glarner Alps, Switzerland, providing detailed mapping of landslide and related Quaternary phenomena, revised volume estimates for each event, and surface exposure dating of rock avalanche deposits. The Rautispitz rock avalanche originated from the southern flank of the Obersee valley, releasing approximately 91 million m3 of limestone on steeply-dipping bedding planes. Debris had maximum horizontal travel distance of ~ 5000 m, a fahrboeschung angle (relating fall height to length) of 18°, and was responsible for the creation of Lake Obersee; deposits are more than 130 m thick in places. The Platten rock avalanche encompassed a source volume of 11 million m3 sliding from the northern flank of the Obersee valley on similar steeply-dipping limestone beds (bedrock forms a syncline under the valley). Debris had a maximum horizontal travel distance of 1600 m with a fahrboeschung angle of 21°, and is more than 80 m thick in places. Deposits of the Platten rock avalanche are superposed atop those from the Rautispitz event at the end of the Obersee valley where they dam Lake Haslensee. Runout for both events was simulated using the dynamic analysis code DAN3D; results showed excellent match to mapped deposit extents and thickness and helped confirm the hypothesized single-event failure scenarios. 36Cl cosmogenic nuclide surface exposure dating of 13 deposited boulders revealed a Younger Dryas age of 12.6 ± 1.0 ka for the Rautispitz rock avalanche and a mid-Holocene age of 6.1 ± 0.8 ka for the Platten rock avalanche. A seismological trigger is proposed for the former event due to potentially correlated turbidite deposits in nearby Lake Zurich.

  14. Counseling in Switzerland: Past, Present, and Future

    ERIC Educational Resources Information Center

    Thomas, Roslyn; Henning, Stacy

    2012-01-01

    The authors review counseling in Switzerland and compare it with counseling in the United States. They evaluate the role of professional associations and programs and argue that the evolution of counseling is situated within the history and economic, social, and political systems of Switzerland. Findings suggest that Swiss counselors are ready to…

  15. Switzerland and the Holocaust: Teaching Contested History

    ERIC Educational Resources Information Center

    Schar, Bernhard C.; Sperisen, Vera

    2010-01-01

    This study is about a history textbook which introduces the new transnational master-narrative of Holocaust memory into the classrooms of the German-speaking part of Switzerland. The script of the book entails a replacement of the formerly dominant view of Switzerland as a neutral nation resisting evil in favour of an image that aligns Switzerland…

  16. Physical effects of thermal pollution in lakes

    NASA Astrophysics Data System (ADS)

    Râman Vinnâ, Love; Wüest, Alfred; Bouffard, Damien

    2017-05-01

    Anthropogenic heat emissions into inland waters influence water temperature and affect stratification, heat and nutrient fluxes, deep water renewal, and biota. Given the increased thermal stress on these systems by growing cooling demands of riparian/coastal infrastructures in combination with climate warming, the question arises on how to best monitor and manage these systems. In this study, we investigate local and system-wide physical effects on the medium-sized perialpine Lake Biel (Switzerland), influenced by point-source cooling water emission from an upstream nuclear power plant (heat emission ˜700 MW, ˜18 W m-2 lake wide). We use one-dimensional (SIMSTRAT) and three-dimensional (Delft3D-Flow) hydrodynamic numerical simulations and provide model resolution guidelines for future studies of thermal pollution. The effects on Lake Biel by the emitted excess heat are summarized as: (i) clear seasonal trend in temperature increase, locally up to 3.4°C and system-wide volume mean ˜0.3°C, which corresponds to one decade of regional surface water climate warming; (ii) the majority of supplied thermal pollution (˜60%) leaves this short residence time (˜58 days) system via the main outlet, whereas the remaining heat exits to the atmosphere; (iii) increased length of stratified period due to the stabilizing effects of additional heat; (iv) system-wide effects such as warmer temperature, prolonged stratified period, and river-caused epilimnion flushing are resolved by both models whereas local raised temperature and river short circuiting was only identifiable with the three-dimensional model approach. This model-based method provides an ideal tool to assess man-made impacts on lakes and their downstream outflows.

  17. Zooplankton communities and Bythotrephes longimanus in lakes of the montane region of the northern Alps

    PubMed Central

    Horváth, Zsófia; Vad, Csaba F.; Preiler, Christian; Birtel, Julia; Matthews, Blake; Ptáčníková, Radka; Ptáčník, Robert

    2017-01-01

    Abstract Lakes in the Alps represent a considerable fraction of nutrient-poor lakes in Central Europe, with unique biodiversity and ecosystem properties. Although some individual lakes are well studied, less knowledge is available on large-scale patterns essential to general understanding of their functioning. Here, we aimed to describe crustacean zooplankton communities (Cladocera, Copepoda) and identify their environmental drivers in the pelagic zone of 54 oligotrophic lakes in the montane region of the Alps (400–1200 m) in Austria, Germany, and Switzerland, covering a spatial scale of 650 km. Moreover, we aimed to provide data on the distribution and ecological requirements of the North American invader Bythotrephes longimanus in its Central European native range. Communities were mainly dominated by widespread species typical of lowland habitats, and only a few true specialists of oligotrophic alpine lakes were present. The most frequent taxa were the Daphnia longispina complex and Eudiaptomus gracilis, with 48 and 45 occurrences, respectively. Species richness decreased with altitude and increased with lake area. The main structuring factors of community composition were chlorophyll a concentration and depth, which drove an apparent separation of mesotrophic and oligotrophic communities. Bythotrephes had 13 occurrences, showing a preference for deep oligotrophic lakes. Its presence was not coupled with lower crustacean species richness, as was repeatedly observed in North America. Additionally, it frequently co-occurred with the other large predatory cladoceran, Leptodora kindtii. B. longimanus might be considered a truly montane species in Central Europe, given its absence in lowland and alpine lakes. PMID:28824797

  18. Zooplankton communities and Bythotrephes longimanus in lakes of the montane region of the northern Alps

    PubMed Central

    Horváth, Zsófia; Vad, Csaba F.; Preiler, Christian; Birtel, Julia; Matthews, Blake; Ptáčníková, Radka; Ptacnik, Robert

    2017-01-01

    Lakes in the Alps represent a considerable fraction of nutrient-poor lakes in Central Europe, with unique biodiversity and ecosystem properties. Although some individual lakes are well-studied, less knowledge is available on large-scale patterns essential to generalise the understanding of their functioning. Here, we aimed to describe crustacean zooplankton communities (Cladocera, Copepoda) and identify their environmental drivers in the pelagic zone of 54 oligotrophic lakes in the montane region of the Alps (400–1200 m) in Austria, Germany, and Switzerland, covering a spatial scale of 650 km. Moreover, we aimed to provide data on the distribution and ecological requirements of the North American invader Bytotrephes longimanus in its Central European native range. Communities were mainly dominated by widespread species typical of lowland habitats, and only a few true specialists of oligotrophic alpine lakes were present. The most frequent taxa were the Daphnia longispina complex and Eudiaptomus gracilis, with 48 and 45 occurrences, respectively. Species richness decreased with altitude and increased with lake area. The main structuring factors of community composition were chlorophyll a concentration and depth, which drove an apparent separation of mesotrophic and oligotrophic communities. Bytotrephes had 13 occurrences, showing a preference for deep oligotrophic lakes. Its presence was not coupled with lower crustacean species richness as it was repeatedly observed in North America. Additionally, it frequently co-occurred with the other large predatory cladoceran, Leptodora kindtii. B. longimanus might be considered a truly montane species in Central Europe, given its absence in lowland and alpine lakes. PMID:28649318

  19. Impacts of the November 2014 extreme rainfall event in Ticino, Switzerland

    NASA Astrophysics Data System (ADS)

    Voumard, Jérémie; Matasci, Battista; Derron, Marc-Henri; Jaboyedoff, Michel

    2015-04-01

    The 2-17th November, a meteorological block in the south of the Alps produced record rain precipitations in the North of Italy and in the canton of Ticino, Switzerland. During those fifteen days, the rain quantity was three to five times higher than the November average monthly rain. The Lugano meteorological station recorded a new precipitation record with 538 mm during this period. During this event, the rainfall triggered many landslides and floods. Four people died in two different events 11 km apart. In the first case, a two-storey house, located in a large wooded area 10 km West of Lugano, was destroyed by a 1'000 m3 landslide composed of mud, trees and rock masses which flew over 150 meters on November 5th 2014. The two occupants, a mother and her three years old daughter, were killed. The second event occurred in an urban area of the Lugano agglomeration where a wall, weakened by the heavy rainfalls, located 50 m away and above a three-storey apartment building broke, releasing 500 m3 to 1'000 m3 of muddy material. Besides two fatalities, one man was seriously injured, three persons were slightly injured and one person kept uninjured. Concerning the transportation network, more than twenty roads and railways were blocked by landslides, floods and rockfalls. Some of them were closed over one month. The two secondary roads to Arogno and Rovio villages were blocked by landslides. The only asphalted access to those villages was a 45 km deviation of more than one hour travel time through Italy. Two hamlets a couple of kilometers away were isolated by a landslide. The only access was by boat from the lake. Two main roads and one railway along the Lake Maggiore and the Tresa River taken by Italian cross-border commuters who work in Switzerland were cut by floods and landslides generating economic and societal inconveniences. The two main lakes of the canton of Ticino -lakes Maggiore and Lugano- reached their maximum flood level. In Locarno, the 3rd biggest city of

  20. eHealth in Switzerland - building consensus, awareness and architecture.

    PubMed

    Lovis, Christian; Looser, Hansjorg; Schmid, Adrian; Wagner, Judith; Wyss, Stefan

    2011-01-01

    This paper reports on the process of the Swiss national strategy to define and implement eHealth. Switzerland is a federal political organization with 26 cantons that are autonomous for the health legal framework. Switzerland must also provide support for four national languages. Thus, this experience addresses many challenges that are experienced at the European level in a much larger scale. Also, Switzerland benefits from the major projects ongoing in Europe, such as epSOS, to define its own strategy.

  1. Assisted Suicide in Switzerland: Clarifying Liberties and Claims.

    PubMed

    Hurst, Samia A; Mauron, Alex

    2017-03-01

    Assisting suicide is legal in Switzerland if it is offered without selfish motive to a person with decision-making capacity. Although the 'Swiss model' for suicide assistance has been extensively described in the literature, the formally and informally protected liberties and claims of assistors and recipients of suicide assistance in Switzerland are incompletely captured in the literature. In this article, we describe the package of rights involved in the 'Swiss model' using the framework of Hohfeldian rights as modified by Wenar. After outlining this framework, we dissect the rights involved in suicide assistance in Switzerland, and compare it with the situation in England and Germany. Based on this approach, we conclude that in Switzerland, claim rights exist for those requesting suicide assistance, and for those who are considering providing such assistance, even though no entitlements exist toward suicide assistance. We then describe the implementation of the 'Swiss model' and difficulties arising within it. Clarifying these issues is important to understand the Swiss situation, to evaluate what features of it may or may not be worth correcting or emulating, and to understand how it can impact requests for suicide assistance in other countries due to 'suicide tourism'. It is also important to understand exactly what sets Switzerland apart from other countries with different legislations regarding suicide assistance. © 2016 John Wiley & Sons Ltd.

  2. Effects of oligotrophication on primary production in peri-alpine lakes

    NASA Astrophysics Data System (ADS)

    Finger, David; Wüest, Alfred; Bossard, Peter

    2013-08-01

    During the second half of the 20th century untreated sewage released from housing and industry into natural waters led to a degradation of many freshwater lakes and reservoirs worldwide. In order to mitigate eutrophication, wastewater treatment plants, including Fe-induced phosphorus precipitation, were implemented throughout the industrialized world, leading to reoligotrophication in many freshwater lakes. To understand and assess the effects of reoligotrophication on primary productivity, we analyzed 28 years of 14C assimilation rates, as well as other biotic and abiotic parameters, such as global radiation, nutrient concentrations and plankton densities in peri-alpine Lake Lucerne, Switzerland. Using a simple productivity-light relationship, we estimated continuous primary production and discussed the relation between productivity and observed limnological parameters. Furthermore, we assessed the uncertainty of our modeling approach based on monthly 14C assimilation measurements using Monte Carlo simulations. Results confirm that monthly sampling of productivity is sufficient for identifying long-term trends in productivity and that conservation management has successfully improved water quality during the past three decades via reducing nutrients and primary production in the lake. However, even though nutrient concentrations have remained constant in recent years, annual primary production varies significantly from year to year. Despite the fact that nutrient concentrations have decreased by more than an order of magnitude, primary production has decreased only slightly. These results suggest that primary production correlates well to nutrients availability but meteorological conditions lead to interannual variability regardless of the trophic status of the lake. Accordingly, in oligotrophic freshwaters meteorological forcing may reduce productivity impacting on the entire food chain of the ecosystem.

  3. Switzerland and Its Educational System: From Babylon zu Multiculturalism.

    ERIC Educational Resources Information Center

    Allemann-Ghionda, Cristina

    1994-01-01

    Discusses the paradoxes of the current policies toward multiculturalism and multilingualism in Switzerland. Asserts that policy perspectives lean toward diversity rather than assimilation. Proposes options for an educational concept in a linguistically and culturally plural Switzerland, embedded in Europe. (CFR)

  4. Can ipids in lake sediments help to reconstruct changes in methane availability and methane fluxes in boreal and temperate lakes?

    NASA Astrophysics Data System (ADS)

    Stoetter, T.; van Hardenbroek, M.; Rinta, P.; Schilder, J.; Schubert, C. J.; Heiri, O.

    2013-12-01

    Methane (CH4) is a major greenhouse gas and lakes are an important but poorly studied source of CH4 to the atmosphere. Lipid analysis was used before to identify and quantify CH4 oxidizing bacteria (MOB), giving insight into CH4 oxidation and production in lakes. However, few studies are available that examine how closely the distribution and the carbon isotopic signature (δ13C) of lipids are related to CH4 concentrations and fluxes in different lake ecosystems. In a multi-lake survey we quantified the relationship between lipids, mainly fatty acids (FAs), and CH4 concentrations or fluxes, with the aim of assessing whether FA analysis of lake sediment samples can provide information on past CH4 abundance and production in lakes. The study sites include small lakes in Sweden, Finland, the Netherlands, and Switzerland. Surface sediments collected in the deepest point of the lakes were examined using gas chromatography with flame ionization for determining FA concentrations, gas chromatography mass spectrometry (GC-MS) for identification of individual FAs, and isotope ratio mass spectrometry (IRMS) for determining compound specific δ13C values. Since CH4 is significantly more depleted in 13C than other carbon sources, δ13C is a good tracer for CH4 related processes. The analysis of the acid fraction in the sediments showed that mainly three FAs, identified as C16:1ω7, C16:1ω5 and C18:1ω7, were more depleted in 13C than the others, suggesting that they may originate from MOB. Comparison with literature sources indicated that these FAs are produced by MOB, however, not exclusively. The relative abundance of these depleted FAs showed clear relations to CH4 parameters. For example, increasing abundances were observed with increasing CH4 concentrations in the sediment or with increasing CH4 flux measured at the lake surface. An explanation for these relations would be an increase in MOB biomass with increasing CH4 availability, as they use CH4 as energy and carbon

  5. Jungfrau and Interlaken, Switzerland

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Bernese Alps form the centerpiece of this late summer view of Switzerland; Jungfrau (J - 4158 m), Moench (M - 4089 m), and Eiger (E - 3970 m) are among the higher peaks of the Central Alps. North of the range is the city of Interlaken, flanked by the Thune See and Brienzer See (lakes); the long, straight-segmented valley of the Rhone lies to the south. On the southern flank of the Jungfrau massif is the Aletsch glacier, meltwaters of which feed the upper Rhone; another source is the Rhone glacier at the eastern end of the valley. One estimate holds that roughly half the ice in glaciers of the European Alps has melted since 1850 (http://www.geographical.co.uk/geographical/features/feb_2001_climate.html). U-shaped valleys carved by glaciers are clearly visible; some, such as that of the Rhone, have been modified by through-flowing rivers. The Swiss Alps are elements of a great mountain system that was constructed as Africa and Eurasia collided, starting more than 90 million years ago. Ancient basement rocks (>325 million years old) of the Bernese Alps were uplifted, folded, and forced northward between 29 and 10 million years ago. Reference: Trumpy, R., 1997, Alpine orogeny, in Moores, E. M. and Fairbridge, R. W., editors, Encyclopedia of European and Asian Regional Geology: London, Chapman and Hall, pages 16-26. STS106-718-09 was taken in September, 2001 by the crew of Space Shuttle mission 106 using a Hasselblad camera with 250-mm lens. The image is provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth.

  6. On the Relevance of Bernstein for German-Speaking Switzerland

    ERIC Educational Resources Information Center

    Bolander, Brook

    2009-01-01

    This article assesses the relevance of Basil Bernstein for German-speaking Switzerland. It argues that Bernstein is potentially relevant for German-speaking Switzerland in light of contemporary studies which highlight a connection between social background and differential school achievement. After contextualising Bernstein's theoretical outlook…

  7. Temporal Clustering of Regional-Scale Extreme Precipitation Events in Southern Switzerland

    NASA Astrophysics Data System (ADS)

    Barton, Yannick; Giannakaki, Paraskevi; Von Waldow, Harald; Chevalier, Clément; Pfhal, Stephan; Martius, Olivia

    2017-04-01

    Temporal clustering of extreme precipitation events on subseasonal time scales is a form of compound extremes and is of crucial importance for the formation of large-scale flood events. Here, the temporal clustering of regional-scale extreme precipitation events in southern Switzerland is studied. These precipitation events are relevant for the flooding of lakes in southern Switzerland and northern Italy. This research determines whether temporal clustering is present and then identifies the dynamics that are responsible for the clustering. An observation-based gridded precipitation dataset of Swiss daily rainfall sums and ECMWF reanalysis datasets are used. To analyze the clustering in the precipitation time series a modified version of Ripley's K function is used. It determines the average number of extreme events in a time period, to characterize temporal clustering on subseasonal time scales and to determine the statistical significance of the clustering. Significant clustering of regional-scale precipitation extremes is found on subseasonal time scales during the fall season. Four high-impact clustering episodes are then selected and the dynamics responsible for the clustering are examined. During the four clustering episodes, all heavy precipitation events were associated with an upperlevel breaking Rossby wave over western Europe and in most cases strong diabatic processes upstream over the Atlantic played a role in the amplification of these breaking waves. Atmospheric blocking downstream over eastern Europe supported this wave breaking during two of the clustering episodes. During one of the clustering periods, several extratropical transitions of tropical cyclones in the Atlantic contributed to the formation of high-amplitude ridges over the Atlantic basin and downstream wave breaking. During another event, blocking over Alaska assisted the phase locking of the Rossby waves downstream over the Atlantic.

  8. Primary care in Switzerland gains strength.

    PubMed

    Djalali, Sima; Meier, Tatjana; Hasler, Susann; Rosemann, Thomas; Tandjung, Ryan

    2015-06-01

    Although there is widespread agreement on health- and cost-related benefits of strong primary care in health systems, little is known about the development of the primary care status over time in specific countries, especially in countries with a traditionally weak primary care sector such as Switzerland. The aim of our study was to assess the current strength of primary care in the Swiss health care system and to compare it with published results of earlier primary care assessments in Switzerland and other countries. A survey of experts and stakeholders with insights into the Swiss health care system was carried out between February and March 2014. The study was designed as mixed-modes survey with a self-administered questionnaire based on a set of 15 indicators for the assessment of primary care strength. Forty representatives of Swiss primary and secondary care, patient associations, funders, health care authority, policy makers and experts in health services research were addressed. Concordance between the indicators of a strong primary care system and the real situation in Swiss primary care was rated with 0-2 points (low-high concordance). A response rate of 62.5% was achieved. Participants rated concordance with five indicators as 0 (low), with seven indicators as 1 (medium) and with three indicators as 2 (high). In sum, Switzerland achieved 13 of 30 possible points. Low scores were assigned because of the following characteristics of Swiss primary care: inequitable local distribution of medical resources, relatively low earnings of primary care practitioners compared to specialists, low priority of primary care in medical education and training, lack of formal guidelines for information transfer between primary care practitioners and specialists and disregard of clinical routine data in the context of medical service planning. Compared to results of an earlier assessment in Switzerland, an improvement of seven indicators could be stated since 1995. As a

  9. Abrupt stop of deep water turnover with lake warming: Drastic consequences for algal primary producers.

    PubMed

    Yankova, Yana; Neuenschwander, Stefan; Köster, Oliver; Posch, Thomas

    2017-10-23

    After strong fertilization in the 20 th century, many deep lakes in Central Europe are again nutrient poor due to long-lasting restoration (re-oligotrophication). In line with reduced phosphorus and nitrogen loadings, total organismic productivity decreased and lakes have now historically low nutrient and biomass concentrations. This caused speculations that restoration was overdone and intended fertilizations are needed to ensure ecological functionality. Here we show that recent re-oligotrophication processes indeed accelerated, however caused by lake warming. Rising air temperatures strengthen thermal stabilization of water columns which prevents thorough turnover (holomixis). Reduced mixis impedes down-welling of oxygen rich epilimnetic (surface) and up-welling of phosphorus and nitrogen rich hypolimnetic (deep) water. However, nutrient inputs are essential for algal spring blooms acting as boost for annual food web successions. We show that repeated lack (since 1977) and complete stop (since 2013) of holomixis caused drastic epilimnetic phosphorus depletions and an absence of phytoplankton spring blooms in Lake Zurich (Switzerland). By simulating holomixis in experiments, we could induce significant vernal algal blooms, confirming that there would be sufficient hypolimnetic phosphorus which presently accumulates due to reduced export. Thus, intended fertilizations are highly questionable, as hypolimnetic nutrients will become available during future natural or artificial turnovers.

  10. A satellite-based climatology of European alpine lake surface water temperature for the period 1989-2013

    NASA Astrophysics Data System (ADS)

    Riffler, M.; Lieberherr, G.; Wunderle, S.

    2014-12-01

    Lake water temperature (LWT) is an important driver of lake ecosystems and it has been identified as an indicator of climate change. At some European lakes LWT has been observed over several decades, but the majority of lakes is not monitored, or only on a non-regular basis, which is insufficient to track a climate signal. Satellite observations might be utilized to fill these gaps, however, only few satellite sensors offer the possibility to analyze time series which cover 25 years or more. The Advanced Very High Resolution Radiometer (AVHRR) is among these and has been flown as a heritage instrument for almost 35 years. It will be carried on for at least ten more years finally offering a unique opportunity for satellite-based climate studies. We present a satellite-based lake surface water temperature (LSWT) data set for European (pre-alpine) water bodies based on the extensive AVHRR 1 km data record (1989-2013) of the Remote Sensing Research Group at the University of Bern, Switzerland. It has been compiled out of AVHRR/2 (NOAA-07, -09, -11, -14) and AVHRR/3 (NOAA-16, -17, -18, -19 and Metop-A) day and night time data. We will discuss the processing steps (e.g. geolocation, calibration, LSWT algorithm, etc.) which are necessary to obtain the accuracy needed for climate related studies. The resulting climatology covers pre-alpine and alpine lakes with sizes between 14 and 580 km2. We will present and discuss the analysis of trends for some sample lakes in various regions of the Alps.

  11. Valuing water resources in Switzerland using a hedonic price model

    NASA Astrophysics Data System (ADS)

    van Dijk, Diana; Siber, Rosi; Brouwer, Roy; Logar, Ivana; Sanadgol, Dorsa

    2016-05-01

    In this paper, linear and spatial hedonic price models are applied to the housing market in Switzerland, covering all 26 cantons in the country over the period 2005-2010. Besides structural house, neighborhood and socioeconomic characteristics, we include a wide variety of new environmental characteristics related to water to examine their role in explaining variation in sales prices. These include water abundance, different types of water bodies, the recreational function of water, and water disamenity. Significant spatial autocorrelation is found in the estimated models, as well as nonlinear effects for distances to the nearest lake and large river. Significant effects are furthermore found for water abundance and the distance to large rivers, but not to small rivers. Although in both linear and spatial models water related variables explain less than 1% of the price variation, the distance to the nearest bathing site has a larger marginal contribution than many neighborhood-related distance variables. The housing market shows to differentiate between different water related resources in terms of relative contribution to house prices, which could help the housing development industry make more geographically targeted planning activities.

  12. "Ich kam unter die Schweizer": Teaching Switzerland as a Multi-Ethnic Society

    ERIC Educational Resources Information Center

    Baumgartner, Karin

    2012-01-01

    This article describes a five-week module on "Switzerland as a multi-ethnic society" intended to counteract the popular image of Switzerland as a homogenous country concerned mostly with tourism, chocolate, and watches. Instead, the module treats Switzerland through topics such as the definition of identity in a multi-ethnic society, the…

  13. Toward a Lake Ice Phenology Derived from VIIRS Data

    NASA Astrophysics Data System (ADS)

    Sütterlin, Melanie; Duguay-Tetzlaff, Anke; Wunderle, Stefan

    2017-04-01

    Ice cover on lakes plays an essential role in the physical, chemical, and biological processes of freshwater systems (e.g., ice duration controls the seasonal heat budget of lakes), and it also has many economic implications (e.g., for hydroelectricity, transportation, winter tourism). The variability and trends in the seasonal cycle of lake ice (e.g., timing of freeze-up and break-up) represent robust and direct indicators of climate change; they therefore emphasize the importance of monitoring lake ice phenology. Satellite remote sensing has proven its great potential for detecting and measuring the ice cover on lakes. Different remote sensing systems have been successfully used to collect recordings of freeze-up, break-up, and ice thickness and increase the spatial and temporal coverage of ground-based observations. Therefore, within the Global Climate Observing System (GCOS) Swiss project, "Integrated Monitoring of Ice in Selected Swiss Lakes," initiated by MeteoSwiss, satellite images from various sensors and different approaches are used and compared to perform investigations aimed at integrated monitoring of lake ice in Switzerland and contributing to the collection of lake ice phenology recordings. Within the framework of this project, the Remote Sensing Research Group of the University of Bern (RSGB) utilizes data acquired in the fine-resolution imagery (I) bands (1-5) of the Visible Infrared Imaging Radiometer Suite (VIIRS) sensor that is mounted onboard the SUOMI-NPP. Visible and near-infrared reflectances, as well as thermal infrared-derived lake surface water temperatures (LSWT), are used to retrieve lake ice phenology dates. The VIIRS instrument, which combines a high temporal resolution ( 2 times per day) with a reasonable spatial resolution (375 m), is equipped with a single broad-band thermal I-channel (I05). Thus, a single-channel LSWT retrieval algorithm is employed to correct for the atmospheric influence. The single channel algorithm applied in

  14. Monthly Rainfall Erosivity Assessment for Switzerland

    NASA Astrophysics Data System (ADS)

    Schmidt, Simon; Meusburger, Katrin; Alewell, Christine

    2016-04-01

    Water erosion is crucially controlled by rainfall erosivity, which is quantified out of the kinetic energy of raindrop impact and associated surface runoff. Rainfall erosivity is often expressed as the R-factor in soil erosion risk models like the Universal Soil Loss Equation (USLE) and its revised version (RUSLE). Just like precipitation, the rainfall erosivity of Switzerland has a characteristic seasonal dynamic throughout the year. This inter-annual variability is to be assessed by a monthly and seasonal modelling approach. We used a network of 86 precipitation gauging stations with a 10-minute temporal resolution to calculate long-term average monthly R-factors. Stepwise regression and Monte Carlo Cross Validation (MCCV) was used to select spatial covariates to explain the spatial pattern of R-factor for each month across Switzerland. The regionalized monthly R-factor is mapped by its individual regression equation and the ordinary kriging interpolation of its residuals (Regression-Kriging). As covariates, a variety of precipitation indicator data has been included like snow height, a combination of hourly gauging measurements and radar observations (CombiPrecip), mean monthly alpine precipitation (EURO4M-APGD) and monthly precipitation sums (Rhires). Topographic parameters were also significant explanatory variables for single months. The comparison of all 12 monthly rainfall erosivity maps showed seasonality with highest rainfall erosivity in summer (June, July, and August) and lowest rainfall erosivity in winter months. Besides the inter-annual temporal regime, a seasonal spatial variability was detectable. Spatial maps of monthly rainfall erosivity are presented for the first time for Switzerland. The assessment of the spatial and temporal dynamic behaviour of the R-factor is valuable for the identification of more susceptible seasons and regions as well as for the application of selective erosion control measures. A combination with monthly vegetation

  15. Iron supplementation in Switzerland - A bi-national, descriptive and observational study.

    PubMed

    Biétry, Fabienne A; Hug, Balthasar; Reich, Oliver; Susan, Jick S; Meier, Christoph Rudolf

    2017-07-11

    Iron deficiency is the most common nutritional disorder in the world, and it is the only common nutrient deficiency in industrialised nations. It is thought to be the most common cause of anaemia. Use of iron supplementation in Switzerland has not been previously quantified in detail. We quantified use of iron supplementation from Swiss data and compared it with data from the UK. We assessed the frequency of serum ferritin and haemoglobin tests prior to newly started iron therapy to see whether use was based on documented low iron levels or blood parameters, especially in the case of parenteral iron supplementation. We conducted a retrospective descriptive study of prescription iron supplementation use, and compared use of oral or parenteral iron drugs between Switzerland (CH) and the UK. We retrieved Swiss data from the Swiss Health Insurance Helsana Group, and UK data were from the Clinical Practice Research Datalink (CPRD). The study period was 2012 to 2014. The 3-year prevalence of iron supplementation was 9.4% in Switzerland and 4.4% in the UK. Iron use increased slightly between 2012 and 2014 in both countries (CH +0.3%, UK +0.2%). Recorded parenteral iron administration was roughly a thousand times higher in Switzerland (1.9%) than in the UK in 2014. In Switzerland, iron supplements were mostly given to patients aged 20 to 49 years or older than of 80 years. In the UK, iron supplementation was less frequent in younger people, but more prevalent in the elderly. Prior to a first iron prescription, ferritin tests were done more frequently in Switzerland (oral 67.2%, parenteral 86.6%) than in the UK (oral 43.3%, parenteral 65.5%). Haemoglobin was measured before a new parenteral iron therapy rarely in Switzerland (oral 14.9%, parenteral 11.7%), but frequently in the UK (oral 77.4%, parenteral 85.6%). Iron supplementation is more common in Switzerland than in the UK, particularly parenteral iron supplementation. Haemoglobin measurements prior to a new parenteral

  16. [Bites of venomous snakes in Switzerland].

    PubMed

    Plate, Andreas; Kupferschmidt, Hugo; Schneemann, Markus

    2016-06-08

    Although snake bites are rare in Europe, there are a constant number of snake bites in Switzerland. There are two domestic venomous snakes in Switzerland: the aspic viper (Vipera aspis) and the common European adder (Vipera berus). Bites from venomous snakes are caused either by one of the two domestic venomous snakes or by an exotic venomous snake kept in a terrarium. Snake- bites can cause both a local and/or a systemic envenoming. Potentially fatal systemic complications are related to disturbances of the hemostatic- and cardiovascular system as well as the central or peripheral nervous system. Beside a symptomatic therapy the administration of antivenom is the only causal therapy to neutralize the venomous toxins.

  17. Venture Capital Investment in the Life Sciences in Switzerland.

    PubMed

    Hosang, Markus

    2014-12-01

    Innovation is one of the main driving factors for continuous and healthy economic growth and welfare. Switzerland as a resource-poor country is particularly dependent on innovation, and the life sciences, which comprise biotechnologies, (bio)pharmaceuticals, medical technologies and diagnostics, are one of the key areas of innovative strength of Switzerland. Venture capital financing and venture capitalists (frequently called 'VCs') and investors in public equities have played and still play a pivotal role in financing the Swiss biotechnology industry. In the following some general features of venture capital investment in life sciences as well as some opportunities and challenges which venture capital investors in Switzerland are facing are highlighted. In addition certain means to counteract these challenges including the 'Zukunftsfonds Schweiz' are discussed.

  18. Excess mortality during the warm summer of 2015 in Switzerland.

    PubMed

    Vicedo-Cabrera, Ana M; Ragettli, Martina S; Schindler, Christian; Röösli, Martin

    2016-01-01

    In Switzerland, summer 2015 was the second warmest summer for 150 years (after summer 2003). For summer 2003, a 6.9% excess mortality was estimated for Switzerland, which corresponded to 975 extra deaths. The impact of the heat in summer 2015 in Switzerland has not so far been evaluated. Daily age group-, gender- and region-specific all-cause excess mortality during summer (June-August) 2015 was estimated, based on predictions derived from quasi-Poisson regression models fitted to the daily mortality data for the 10 previous years. Estimates of excess mortality were derived for 1 June to 31 August, at national and regional level, as well as by month and for specific heat episodes identified in summer 2015 by use of seven different definitions. 804 excess deaths (5.4%, 95% confidence interval [CI] 3.0‒7.9%) were estimated for summer 2015 compared with previous summers, with the highest percentage obtained for July (11.6%, 95% CI 3.7‒19.4%). Seventy-seven percent of deaths occurred in people aged 75 years and older. Ticino (10.3%, 95% CI -1.8‒22.4%), Northwestern Switzerland (9.5%, 95% CI 2.7‒16.3%) and Espace Mittelland (8.9%, 95% CI 3.7‒14.1%) showed highest excess mortality during this three-month period, whereas fewer deaths than expected (-3.3%, 95% CI -9.2‒2.6%) were observed in Eastern Switzerland, the coldest region. The largest excess estimate of 23.7% was obtained during days when both maximum apparent and minimum night-time temperature reached extreme values (+32 and +20 °C, respectively), with 31.0% extra deaths for periods of three days or more. Heat during summer 2015 was associated with an increase in mortality in the warmer regions of Switzerland and it mainly affected older people. Estimates for 2015 were only a little lower compared to those of summer 2003, indicating that mitigation measures to prevent heat-related mortality in Switzerland have not become noticeably effective in the last 10 years.

  19. Effects of internal phosphorus loadings and food-web structure on the recovery of a deep lake from eutrophication

    USGS Publications Warehouse

    Lepori, Fabio; Roberts, James J.

    2017-01-01

    We used monitoring data from Lake Lugano (Switzerland and Italy) to assess key ecosystem responses to three decades of nutrient management (1983–2014). We investigated whether reductions in external phosphorus loadings (Lext) caused declines in lake phosphorus concentrations (P) and phytoplankton biomass (Chl a), as assumed by the predictive models that underpinned the management plan. Additionally, we examined the hypothesis that deep lakes respond quickly to Lext reductions. During the study period, nutrient management reduced Lext by approximately a half. However, the effects of such reduction on P and Chl a were complex. Far from the scenarios predicted by classic nutrient-management approaches, the responses of P and Chl a did not only reflect changes in Lext, but also variation in internal P loadings (Lint) and food-web structure. In turn, Lint varied depending on basin morphometry and climatic effects, whereas food-web structure varied due to apparently stochastic events of colonization and near-extinction of key species. Our results highlight the complexity of the trajectory of deep-lake ecosystems undergoing nutrient management. From an applied standpoint, they also suggest that [i] the recovery of warm monomictic lakes may be slower than expected due to the development of Lint, and that [ii] classic P and Chl a models based on Lext may be useful in nutrient management programs only if their predictions are used as starting points within adaptive frameworks.

  20. Debates about assisted suicide in Switzerland.

    PubMed

    Burkhardt, Sandra; La Harpe, Romano

    2012-12-01

    Assisted suicide is allowed in 3 states of the United States (Oregon, Washington, Montana) but only if performed by a physician.On the opposite, in Switzerland, at the beginning of the 20th century, the Swiss Penal Code referred to assisted suicide in the context of honor or an unhappy love affair. It was only in 1985 that Exit Deutsche Schweiz (Exit for German-speaking Switzerland) "medically" assisted the first patient to end his life.Even if authorized by the Swiss law upon certain conditions, assisted suicide is subject to debates for ethical reasons. The Swiss Academy of Medical Sciences described directives to guide physicians on this difficult subject.Different studies showed an increase in the number of medical-assisted suicide in Switzerland since the 1990s. Now, this number seems to be quite stable. Assisted suicide is authorized in a few hospitals under strict conditions (especially when returning home is impossible).Thus, according to the Swiss law, any person could perform assisted suicide; this is essentially performed by 3 main associations, using pentobarbital on medical prescription as lethal substance.Generally speaking, the Swiss population is rather in favor of assisted suicide. Among politics, the debate has been tough until 2010, when the Federal Council decided not to modify the Swiss Penal Code concerning assisted suicide.

  1. A satellite-based climatology (1989-2012) of lake surface water temperature from AVHRR 1-km for Central European water bodies

    NASA Astrophysics Data System (ADS)

    Riffler, Michael; Wunderle, Stefan

    2013-04-01

    The temperature of lakes is an important parameter for lake ecosystems influencing the speed of physio-chemical reactions, the concentration of dissolved gazes (e.g. oxygen), and vertical mixing. Even small temperature changes might have irreversible effects on the lacustrine system due to the high specific heat capacity of water. These effects could alter the quality of lake water depending on parameters like lake size and volume. Numerous studies mention lake water temperature as an indicator of climate change and in the Global Climate Observing System (GCOS) requirements it is listed as an essential climate variable. In contrast to in situ observations, satellite imagery offers the possibility to derive spatial patterns of lake surface water temperature (LSWT) and their variability. Moreover, although for some European lakes long in situ time series are available, the temperatures of many lakes are not measured or only on a non-regular basis making these observations insufficient for climate monitoring. However, only few satellite sensors offer the possibility to analyze time series which cover more than 20 years. The Advanced Very High Resolution Radiometer (AVHRR) is among these and has been flown on the National Oceanic and Atmospheric Administration (NOAA) Polar Operational Environmental Satellites (POES) and on the Meteorological Operational Satellites (MetOp) from the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) as a heritage instrument for almost 35 years. It will be carried on for at least ten more years finally offering a unique opportunity for satellite-based climate studies. Herein we present the results from a study initiated by the Swiss GCOS office to generate a satellite-based LSWT climatology for the pre-alpine water bodies in Switzerland. It relies on the extensive AVHRR 1-km data record (1985-2012) of the Remote Sensing Research Group at the University of Bern (RSGB) and has been derived from the AVHRR/2

  2. Evidence of Lake Trout reproduction at Lake Michigan's mid-lake reef complex

    USGS Publications Warehouse

    Janssen, J.; Jude, D.J.; Edsall, T.A.; Paddock, R.W.; Wattrus, N.; Toneys, M.; McKee, P.

    2006-01-01

    The Mid-Lake Reef Complex (MLRC), a large area of deep (> 40 m) reefs, was a major site where indigenous lake trout (Salvelinus namaycush) in Lake Michigan aggregated during spawning. As part of an effort to restore Lake Michigan's lake trout, which were extirpated in the 1950s, yearling lake trout have been released over the MLRC since the mid-1980s and fall gill net censuses began to show large numbers of lake trout in spawning condition beginning about 1999. We report the first evidence of viable egg deposition and successful lake trout fry production at these deep reefs. Because the area's existing bathymetry and habitat were too poorly known for a priori selection of sampling sites, we used hydroacoustics to locate concentrations of large fish in the fall; fish were congregating around slopes and ridges. Subsequent observations via unmanned submersible confirmed the large fish to be lake trout. Our technological objectives were driven by biological objectives of locating where lake trout spawn, where lake trout fry were produced, and what fishes ate lake trout eggs and fry. The unmanned submersibles were equipped with a suction sampler and electroshocker to sample eggs deposited on the reef, draw out and occasionally catch emergent fry, and collect egg predators (slimy sculpin Cottus cognatus). We observed slimy sculpin to eat unusually high numbers of lake trout eggs. Our qualitative approaches are a first step toward quantitative assessments of the importance of lake trout spawning on the MLRC.

  3. 77 FR 41686 - Safety Zone; Sheffield Lake Fireworks, Lake Erie, Sheffield Lake, OH

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-16

    ...-AA00 Safety Zone; Sheffield Lake Fireworks, Lake Erie, Sheffield Lake, OH AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing a temporary safety zone on Lake Erie, Sheffield Lake, OH. This safety zone is intended to restrict vessels from a portion of Lake Erie...

  4. Lake trout rehabilitation in Lake Ontario

    USGS Publications Warehouse

    Elrod, Joseph H.; O'Gorman, Robert; Schneider, Clifford P.; Eckert, Thomas H.; Schaner, Ted; Bowlby, James N.; Schleen, Larry P.

    1995-01-01

    Attempts to maintain the native lake trout (Salvelinus namaycush) population in Lake Ontario by stocking fry failed and the species was extirpated by the 1950s. Hatchery fish stocked in the 1960s did not live to maturity because of sea lamprey (Petromyzon marinus) predation and incidental commercial harvest. Suppression of sea lampreys began with larvicide treatments of Lake Ontario tributaries in 1971 and was enhanced when the tributaries of Oneida Lake and Lake Erie were treated in the 1980s. Annual stocking of hatchery fish was resumed with the 1972 year class and peaked at about 1.8 million yearlings and 0.3 million fingerlings from the 1985–1990 year classes. Survival of stocked yearlings declined over 50% in the 1980 s and was negatively correlated with the abundance of lake trout > 550 mm long (r = −0.91, P < 0.01, n = 12). A slot length limit imposed by the State of New York for the 1988 fishing season reduced angler harvest. Angler harvest in Canadian waters was 3 times higher in eastern Lake Ontario than in western Lake Ontario. For the 1977–1984 year classes, mean annual survival rate of lake trout age 6 and older was 0.45 (range: 0.35–0.56). In U.S. waters during 1985–1992, the total number of lake trout harvested by anglers was about 2.4 times greater than that killed by sea lampreys. The number of unmarked lake trout < 250 mm long in trawl catches in 1978–1992 was not different from that expected due to loss of marks and failure to apply marks at the hatchery, and suggested that recruitment of naturally-produced fish was nil. However, many of the obstacles which may have impeded lake trout rehabilitation in Lake Ontario during the 1980s are slowly being removed, and there are signs of a general ecosystem recovery. Significant recruitment of naturally produced lake trout by the year 2000, one interim objective of the rehabilitation plan for the Lake, may be achieved.

  5. [Legal and illegal abortion in Switzerland].

    PubMed

    Stamm, H

    1970-01-01

    Aspects of legal and illegal abortion in Switzerland are discussed. About 110,000 births, 25,000 therapeutic abortions (75% for psychiatric indications) and an estimated 50,000 illegal abortions occur annually in Switzerland. Although the mortality and morbidity of therapeutic aborti on are similar to those of normal births (1.4 per 1000 and 11%, respectively) the mortality and morbidity of criminal abortions are far greater (3 per 1000 and 73%, respectively). In the author's view, too strict an interpretatiok of Swiss abortion law (which permits abortion to avoid serious harm to the mother's health) does not take into account the severe and lasting emotional and psychological damage which may be caused by unwanted pregnancy, birth, and childraising. In the present social situation, the social and psychological support required by these women is not available; until it is, abortion is to be preferred.

  6. Lake level variability in Silver Lake, Michigan: a response to fluctuations in lake levels of Lake Michigan

    USGS Publications Warehouse

    Fisher, Timothy G.; Loope, Walter L.

    2004-01-01

    Sediment from Silver Lake, Michigan, can be used to constrain the timing and elevation of Lake Michigan during the Nipissing transgression. Silver Lake is separated from Lake Michigan by a barrier/dune complex and the Nipissing, Calumet, and Glenwood shorelines of Lake Michigan are expressed landward of this barrier. Two Vibracores were taken from the lake in February 2000 and contain pebbly sand, sand, buried soils, marl, peat, and sandy muck. It is suggested here that fluctuations in the level of Lake Michigan are reflected in Silver Lake since the Chippewa low phase, and possibly at the end of the Algonquin phase. An age of 12,490 B.P. (10,460±50 14C yrs B.P.) on wood from a buried Entisol may record the falling Algonquin phase as the North Bay outlet opened. A local perched water table is indicated by marl deposited before 7,800 B.P. and peat between 7,760-7,000 B.P. when Lake Michigan was at the low elevation Chippewa phase. Continued deepening of the lake is recorded by the transition from peat to sandy muck at 7,000 B.P. in the deeper core, and with the drowning of an Inceptisol nearly 3 m higher at 6,410 B.P. in the shallower core. A rising groundwater table responding to a rising Lake Michigan base level during the Nipissing transgression, rather than a response to mid-Holocene climate change, explains deepening of Silver Lake. Sandy muck was deposited continually in Silver Lake between Nipissing and modern time. Sand lenses within the muck are presumed to be eolian in origin, derived from sand dunes advancing into the lake on the western side of the basin.

  7. [The development of obstetric ultrasound in Switzerland].

    PubMed

    Zimmermann, Roland

    2005-04-01

    Ultrasound has conquered obstetrics during the last 40 years. Today it is an integral part of antenatal care. Its broad use as a screening method has pushed critics who found open doors at health authorities facing short resources. In Switzerland in early 1996, routine ultrasound as a health technology was temporarily excluded from reimbursement by the health insurances. Under the pressure of the public, the health authorities had to reintroduce reimbursement within a few months. However, reimbursement was linked with several conditions: the ultrasound examination has to be performed by physicians with adequate training and experience; routine ultrasound needs a strict informed consent, and its benefit has to be evidenced. This decision has had a positive impact on quality. After 7 years, Switzerland has a good training program; guidelines for prenatal ultrasound already exist in their second edition, and spot checks of performance showed that quality in Switzerland meets international standards. Ultrasound mainly has a positive cost-effectiveness ratio due to the detection of fetal malformations with consecutive termination of pregnancy. Since termination of pregnancy is ethically questionable, the discussion with respect to reimbursement will most probably go on. In this light, a comprehensive informed consent of the pregnant women is essential.

  8. Microplastic pollution in lakes and lake shoreline sediments - A case study on Lake Bolsena and Lake Chiusi (central Italy).

    PubMed

    Fischer, Elke Kerstin; Paglialonga, Lisa; Czech, Elisa; Tamminga, Matthias

    2016-06-01

    Rivers and effluents have been identified as major pathways for microplastics of terrestrial sources. Moreover, lakes of different dimensions and even in remote locations contain microplastics in striking abundances. This study investigates concentrations of microplastic particles at two lakes in central Italy (Lake Bolsena, Lake Chiusi). A total number of six Manta Trawls have been carried out, two of them one day after heavy winds occurred on Lake Bolsena showing effects on particle distribution of fragments and fibers of varying size categories. Additionally, 36 sediment samples from lakeshores were analyzed for microplastic content. In the surface waters 2.68 to 3.36 particles/m(3) (Lake Chiusi) and 0.82 to 4.42 particles/m(3) (Lake Bolsena) were detected, respectively. Main differences between the lakes are attributed to lake characteristics such as surface and catchment area, depth and the presence of local wind patterns and tide range at Lake Bolsena. An event of heavy winds and moderate rainfall prior to one sampling led to an increase of concentrations at Lake Bolsena which is most probable related to lateral land-based and sewage effluent inputs. The abundances of microplastic particles in sediments vary from mean values of 112 (Lake Bolsena) to 234 particles/kg dry weight (Lake Chiusi). Lake Chiusi results reveal elevated fiber concentrations compared to those of Lake Bolsena what might be a result of higher organic content and a shift in grain size distribution towards the silt and clay fraction at the shallow and highly eutrophic Lake Chiusi. The distribution of particles along different beach levels revealed no significant differences. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Integrated care organizations in Switzerland

    PubMed Central

    Berchtold, Peter; Peytremann-Bridevaux, Isabelle

    2011-01-01

    Introduction The Swiss health care system is characterized by its decentralized structure and high degree of local autonomy. Ambulatory care is provided by physicians working mainly independently in individual private practices. However, a growing part of primary care is provided by networks of physicians and health maintenance organizations (HMOs) acting on the principles of gatekeeping. Towards integrated care in Switzerland The share of insured choosing an alternative (managed care) type of basic health insurance and therefore restrict their choice of doctors in return for lower premiums increased continuously since 1990. To date, an average of one out of eight insured person in Switzerland, and one out of three in the regions in north-eastern Switzerland, opted for the provision of care by general practitioners in one of the 86 physician networks or HMOs. About 50% of all general practitioners and more than 400 other specialists have joined a physician networks. Seventy-three of the 86 networks (84%) have contracts with the healthcare insurance companies in which they agree to assume budgetary co-responsibility, i.e., to adhere to set cost targets for particular groups of patients. Within and outside the physician networks, at regional and/or cantonal levels, several initiatives targeting chronic diseases have been developed, such as clinical pathways for heart failure and breast cancer patients or chronic disease management programs for patients with diabetes. Conclusion and implications Swiss physician networks and HMOs were all established solely by initiatives of physicians and health insurance companies on the sole basis of a healthcare legislation (Swiss Health Insurance Law, KVG) which allows for such initiatives and developments. The relevance of these developments towards more integration of healthcare as well as their implications for the future are discussed. PMID:21677845

  10. Einstein's Years in Switzerland

    NASA Astrophysics Data System (ADS)

    Plendl, Hans S.

    2005-11-01

    Albert Einstein left Germany, the country of his birth, in 1894 and moved to Switzerland in 1895. He studied, worked and taught there, except for a year's stay in Prague, until1914. That year he returned to Germany, where he lived until his emigration to the United States in 1933. In 1905, while living with his wife Mileva and their first son Hans Albert in Bern and working as a technical expert at the Swiss Patent Office, he published his dissertation on the determination of molecular dimensions, his papers on Brownian Motion that helped to establish the Kinetic Theory of Heat and on the Photo-Electric Effect that validated the Quantum Theory of Light, and the two papers introducing the Special Theory of Relativity. How the young Einstein could help to lay the foundations of these theories while still working on his dissertation, holding a full-time job and helping to raise a family has evoked much discussion among his biographers. In this contribution, the extent to which living within Swiss society and culture could have made this feat possible will be examined. Old and recent photos of places in Switzerland where Einstein has lived and worked will be shown.

  11. Lake whitefish and lake herring population structure and niche in ten south-central Ontario lakes

    USGS Publications Warehouse

    Carl, Leon M.; McGuiness, Fiona

    2006-01-01

    This study compares simple fish communities of ten oligotrophic lakes in south-central Ontario. Species densities and population size structure vary significantly among these lake communities depending on fish species present beyond the littoral zone. Lake whitefish are fewer and larger in the presence of lake herring than in their absence. Diet analysis indicates that lake whitefish shift from feeding on both plankton and benthic prey when lake herring are absent to a primarily benthic feeding niche in the presence of lake herring. When benthic round whitefish are present, lake whitefish size and density decline and they move lower in the lake compared to round whitefish. Burbot are also fewer and larger in lakes with lake herring than in lakes without herring. Burbot, in turn, appear to influence the population structure of benthic coregonine species. Lower densities of benthic lake whitefish and round whitefish are found in lakes containing large benthic burbot than in lakes with either small burbot or where burbot are absent. Predation on the pelagic larvae of burbot and lake whitefish by planktivorous lake herring alters the size and age structure of these populations. As life history theory predicts, those species with poor larval survival appear to adopt a bet-hedging life history strategy of long-lived individuals as a reproductive reserve.

  12. Heavy precipitation events in northern Switzerland

    NASA Astrophysics Data System (ADS)

    Giannakaki, Paraskevi; Martius, Olivia

    2013-04-01

    Heavy precipitation events in the Alpine region often cause floods, rock-falls and mud slides with severe consequences for population and economy. Breaking synoptic Rossby waves located over western Europe, play a central role in triggering such heavy rain events in southern Switzerland (e.g. Massacand et al. 1998). In contrast, synoptic scale structures triggering heavy precipitation on the north side of the Swiss Alps and orographic effects have so far not been studied comprehensively. An observation based high resolution precipitation data set for Switzerland and the Alps (MeteoSwiss) is used to identify heavy precipitation events affecting the north side of the Swiss Alps for the time period 1961-2010. For these events a detailed statistical and dynamical analysis of the upper level flow is conducted using ECMWFs ERA-40 and ERA-Interim reanalysis data sets. For the analysis north side of the Swiss Alps is divided in two investigation areas north-eastern and western Switzerland following the Swiss climate change scenarios (Bey et al. 2011). A subjective classification of upper level structures triggering heavy precipitation events in the areas of interest is presented. Four classes are defined based on the orientation and formation of the dynamical tropopause during extreme events in the northern part of Switzerland and its sub-regions. The analysis is extended by a climatology of breaking waves and cut-offs following the method of Wernli and Sprenger (2007) to examine their presence and location during extreme events. References Bey I., Croci-Maspoli M., Fuhrer J., Kull C, Appenzeller C., Knutti R. and Schär C. Swiss Climate Change Scenarios CH2011, C2SM, MeteoSwiss, ETH, NCCR Climate, OcCC (2011), http://dx.doi.org/10.3929/ethz-a-006720559 Massacand A., H. Wernli, and H.C. Davies, 1998. Heavy precipitation on the Alpine South side: An upper-level precursor. Geophys. Res. Lett., 25, 1435-1438. MeteoSwiss 2011. Documentation of Meteoswiss grid-data products

  13. Topoclimatological survey of Switzerland

    NASA Technical Reports Server (NTRS)

    Winiger, M. (Principal Investigator)

    1982-01-01

    The application of Heat Capacity Mapping Mission data to subsynoptic climate analysis of Switzerland was examined. The data included the surface temperature distributions of urban heat islands and the Swiss Alps. Analog and digital data evaluation procedures are described as well as the ground truth acquisition and comparison program. The dependence of the temperature distributions on topography and surface coverage types is assessed. The results indicate that air temperature inversion zones are detectable.

  14. Switzerland: the pragmatics of business.

    PubMed

    Bestetti, Gilberto

    2008-01-01

    Switzerland has a population of seven million and approximately 600 medical technology companies are located there. This equates to one company per 12 thousand people and arguably the highest density in the world. The factors that make the country a successful place to do business are outlined in this interview with Professor Bestetti, Head of the CTI Medtech initiative.

  15. Gambling and problem gambling in Switzerland.

    PubMed

    Billieux, Joël; Achab, Sophia; Savary, Jean-Félix; Simon, Olivier; Richter, Frédéric; Zullino, Daniele; Khazaal, Yasser

    2016-09-01

    To provide an overview of gambling and problem gambling in Switzerland, including historical aspects, past and current legislation and policies, treatment options and the research base. A literature search was conducted on two databases (PubMed and PsycINFO), and official government and statistical reports selected from the official websites of four sources (Federal Office of Justice; Federal Gambling Board; Federal Office of Statistics; Swiss Lottery and Betting Board). After a history of banning or partial banning, Swiss gambling became regulated at the beginning of the 20th century through successive laws. The current system is characterized by important differences in the law and policies for casinos and lotteries, and contradictions in the regulation of these two areas are still under debate in order to develop new legislation. Gambling is widespread in Switzerland, and the prevalence of problem gambling in this country was comparable to that in other European countries in 2014. Most gambling treatment facilities are integrated into mental health treatment services that have out-patient programmes, and treatment for problem gambling is covered by a universal compulsory Swiss health insurance system. The availability of public funding for gambling research is still limited. Switzerland needs to develop a more coherent regulatory and prevention policy approach to gambling, overcoming conflicts in the current dual system of federal and cantonal regulation. Recent efforts to enhance funding for gambling research are promising, and could lead to a more systematic analysis of the efficacy of prevention and treatment programmes. © 2016 Society for the Study of Addiction.

  16. Turbidites as proxy for past flood events: Testing this approach in a large clastic system (Lake Geneva, France/Switzerland)

    NASA Astrophysics Data System (ADS)

    Kremer, Katrina; Girardclos, Stéphanie

    2017-04-01

    Turbidites recorded in lake sediments are often used to reconstruct the frequency of past flood and also seismological events. However, for such a reconstruction, the origin and causes of the recorded turbidites need to be clearly identified. In this study, we test if turbidites can be used as paleohydrological archive based on the the sedimentary record of Lake Geneva resulting from inputs by the Rhone and Dranse clastic river systems. Our approach is based on several methods combining high-resolution seismic reflection data with geophysical (magnetic susceptibility, grain size) and high-resolution XRF/XRD data measured on ca. 10-m-long sediment cores (dated by radiocarbon ages and 137Cs activity). This dataset allows distinguishing between the different sources (rivers or hemipelagic sediment) of the turbidites deposited in the deep basin of Lake Geneva. However, no clear distinction between the various trigger processes (mass failures or floods) could be made, thus flood deposits could not be clearly identified. From our results, we also conclude that the lack of turbidite deposits in the deep basin between the 15th and 18th century seems to be linked to a change in turbidite depocentre due to the Rhone River mouth shifting possibly triggered by human activity and not by any direct climate effect. This study demonstrates that a least two conditions are needed to perform an adequate paleohydrological interpretation based on turbidite records: (1) the holistic understanding of the basin sedimentary system and (2) the distinction of flood-induced turbidites from other types of turbidites (mass failures etc.).

  17. Sociodemographic and Behavioural Determinants of a Healthy Diet in Switzerland.

    PubMed

    Marques-Vidal, Pedro; Waeber, Gérard; Vollenweider, Peter; Bochud, Murielle; Stringhini, Silvia; Guessous, Idris

    2015-01-01

    The determinants of a healthy diet have not been studied in Switzerland. This study aimed at assessing the individual and behavioural factors associated with a healthy diet in a Swiss city. Cross-sectional, population-based study conducted between 2009 and 2013 (n = 4,439, 2,383 women, mean age 57.5 ± 10.3 years) in Lausanne. Food consumption was assessed using a validated food frequency questionnaire. Two Mediterranean diet scores (classic score and specific for Switzerland) and the Harvard School of Public Health alternate healthy eating index were computed. For all three dietary scores considered, living in couple or having a high education were associated with a healthier diet. An unhealthy lifestyle (smoking, sedentary behaviour) or a high body mass index were associated with an unhealthier diet. Participants born in Italy, Portugal and Spain had healthier diets than participants born in France or Switzerland. Women and elderly participants had healthier diets than men and young participants according to 2 scores, while no differences were found for the Swiss-specific Mediterranean score. In Switzerland, healthy eating is associated with high education, a healthy lifestyle, marital status and country of origin. The associations with gender and age depend on the dietary score considered. © 2015 S. Karger AG, Basel.

  18. Landslide-generated tsunamis in a perialpine lake: Historical events and numerical models

    NASA Astrophysics Data System (ADS)

    Hilbe, Michael; Anselmetti, Flavio S.

    2014-05-01

    Many of the perialpine lakes in Central Europe - the large, glacier-carved basins formed during the Pleistocene glaciations of the Alps - have proven to be environments prone to subaquatic landsliding. Among these, Lake Lucerne (Switzerland) has a particularly well-established record of subaquatic landslides and related tsunamis. Its sedimentary archive documents numerous landslides over the entire Holocene, which have either been triggered by earthquakes, or which occurred apparently spontaneously, possibly due to rapid sediment accumulation on delta slopes. Due to their controlled boundary conditions and the possibility to be investigated on a complete basinal scale, such lacustrine tsunamis may be used as textbook analogons for their marine counterparts. Two events in the 17th century illustrate these processes and their consequences: In AD 1601, an earthquake (Mw ~ 5.9) led to widespread failure of the sediment drape covering the lateral slopes in several basins. The resulting landslides generated tsunami waves that reached a runup of several metres, as reported in historical accounts. The waves caused widespread damage as well as loss of lives in communities along the shores. In AD 1687, the apparently spontaneous collapse of a river delta in the lake led to similar waves that damaged nearby villages. Based on detailed information on topography, bathymetry and the geometry of the landslide deposits, numerical simulations combining two-dimensional, depth-averaged models for landslide propagation, as well as for tsunami generation, propagation and inundation, are able to reproduce most of the reported tsunami effects for these events. Calculated maximum runup of the waves is 6 to >10 m in the directly affected lake basins, but significantly less in neighbouring basins. Flat alluvial plains adjacent to the most heavily affected areas are inundated over distances of several hundred metres. Taken as scenarios for possible future events, these past events suggest

  19. [Uroliths of cats in Switzerland from 2002 to 2009].

    PubMed

    Gerber, B; Brandenberger-Schenk, F; Rothenanger, E; Müller, C

    2016-10-01

    In this study data on composition of uroliths collected from cats and epidemiologic data of affected cats in Switzerland from 2002 to 2009 are summarised. Of 884 stones analysed 50% (n=441) were composed of calcium oxalate, 45% (n=398) of struvite, 3% (n=18) of ammonium urate, 1% (n=12) were mixed stones, 1% (n=9) were composed of silica, 3 stones were solidified blood, 2 consisted of cystine and 1of xanthine. 40% of the ureteral stones were composed of struvite. Domestic cats had significantly less calcium oxalate stones compared to British Shorthair or Persian cats. Cats with calcium oxalate stones were older and cats with struvite stones were younger than other affected cats. Female and male cats were equally affected with stones. Compared to studies from other countries, in Switzerland silica stones occurred more often and ureteral stones were more often composed of Struvite. The present study shows that occurrence and prevalence of urinary calculi of cats from Switzerland exhibited only slight differences to studies from other countries.

  20. 2016 Lake Michigan Lake Trout Working Group Report

    USGS Publications Warehouse

    Madenjian, Charles P.; Breidert, Brian; Boyarski, David; Bronte, Charles R.; Dickinson, Ben; Donner, Kevin; Ebener, Mark P.; Gordon, Roger; Hanson, Dale; Holey, Mark; Janssen, John; Jonas, Jory; Kornis, Matthew; Olsen, Erik; Robillard, Steve; Treska, Ted; Weldon, Barry; Wright, Greg D.

    2017-01-01

    This report provides a review on the progression of lake trout rehabilitation towards meeting the Salmonine Fish Community Objectives (FCOs) for Lake Michigan (Eshenroder et. al. 1995) and the interim goal and evaluation objectives articulated in A Fisheries Management Implementation Strategy for the Rehabilitation of Lake Trout in Lake Michigan (Dexter et al. 2011); we also include data describing lake trout stocking and mortality to portray the present state of progress towards lake trout rehabilitation.

  1. Contaminants in American alligator eggs from Lake Apopka, Lake Griffin, and Lake Okeechobee, Florida

    USGS Publications Warehouse

    Heinz, Gary H.; Percival, H. Franklin; Jennings, Michael L.

    1991-01-01

    Residues of organochlorine pesticides, polychlorinated biphenyls (PCBs), and 16 elements were measured in American alligator (Alligator mississippiensis) eggs collected in 1984 from Lakes Apopka, Griffin, and Okeechobee in central and south Florida. Organochlorine pesticides were highest in eggs from Lake Apopka. None of the elements appeared to be present at harmful concentrations in eggs from any of the lakes. A larger sample of eggs was collected in 1985, but only from Lakes Griffin, a lake where eggs were relatively clean, and Apopka, where eggs were most contaminated. In 1985, hatching success of artificially incubated eggs was lower for Lake Apopka, and several organochlorine pesticides were higher than in eggs from Lake Griffin. However, within Lake Apopka, higher levels of pesticides in chemically analyzed eggs were not associated with reduced hatching success of the remaining eggs in the clutch. Therefore, it did not appear that any of the pesticides we measured were responsible for the reduced hatching success of Lake Apopka eggs.

  2. Perinatal mental health service provision in Switzerland and in the UK.

    PubMed

    Amiel Castro, Rita T; Schroeder, Katrin; Pinard, Claudia; Blöchlinger, Patricia; Künzli, Hansjörg; Riecher-Rössler, Anita; Kammerer, Martin

    2015-01-01

    The epidemiology of maternal perinatal-psychiatric disorders as well as their effect on the baby is well recognised. Increasingly well researched specialised treatment methods can reduce maternal morbidity, positively affect mother-baby bonding and empower women's confidence as a mother. Here, we aimed to compare guidelines and the structure of perinatal-psychiatric service delivery in the United Kingdom and in Switzerland from the government's perspective. Swiss cantons provided information regarding guidelines and structure of service delivery in 2000. A subsequent survey using the same questionnaire was carried out in 2007. In the UK, similar information was accessed through published reports from 2000-2012. Guidelines for perinatal psychiatry exist in the UK, whereas in Switzerland in 2000 none of the 26 cantons had guidelines, and in 2007 only one canton did. Joint mother-baby admissions on general psychiatric wards were offered by 92% of the Swiss cantons. In the UK, pregnant women and joint mother-baby admissions are only advised onto specialised perinatal-psychiatric units. In Switzerland, in 2007, three specialised units (max. 24 beds) were in place corresponding to 1 unit per 2.5 million people, while in the UK there were 22 mother-baby units (168 beds) in 2012 (1 unit per 2.8 million). In the UK, less than 50% of trusts provided specialised perinatal-psychiatric health care. The main difference between the UK and Switzerland was the absence of guidelines, regular assessment and plans for future development of perinatal psychiatry in Switzerland. There are still geographical differences in the provision of perinatal-psychiatric services in the UK.

  3. Methane oxidation in anoxic lake waters

    NASA Astrophysics Data System (ADS)

    Su, Guangyi; Zopfi, Jakob; Niemann, Helge; Lehmann, Moritz

    2017-04-01

    Freshwater habitats such as lakes are important sources of methante (CH4), however, most studies in lacustrine environments so far provided evidence for aerobic methane oxidation only, and little is known about the importance of anaerobic oxidation of CH4 (AOM) in anoxic lake waters. In marine environments, sulfate reduction coupled to AOM by archaea has been recognized as important sinks of CH4. More recently, the discorvery of anaerobic methane oxidizing denitrifying bacteria represents a novel and possible alternative AOM pathway, involving reactive nitrogen species (e.g., nitrate and nitrite) as electron acceptors in the absence of oxygen. We investigate anaerobic methane oxidation in the water column of two hydrochemically contrasting sites in Lake Lugano, Switzerland. The South Basin displays seasonal stratification, the development of a benthic nepheloid layer and anoxia during summer and fall. The North Basin is permanently stratified with anoxic conditions below 115m water depth. Both Basins accumulate seasonally (South Basin) or permanently (North Basin) large amounts of CH4 in the water column below the chemocline, providing ideal conditions for methanotrophic microorganisms. Previous work revealed a high potential for aerobic methane oxidation within the anoxic water column, but no evidence for true AOM. Here, we show depth distribution data of dissolved CH4, methane oxidation rates and nutrients at both sites. In addition, we performed high resolution phylogenetic analyses of microbial community structures and conducted radio-label incubation experiments with concentrated biomass from anoxic waters and potential alternative electron acceptor additions (nitrate, nitrite and sulfate). First results from the unamended experiments revealed maximum activity of methane oxidation below the redoxcline in both basins. While the incubation experiments neither provided clear evidence for NOx- nor sulfate-dependent AOM, the phylogenetic analysis revealed the

  4. Sanctuaries for lake trout in the Great Lakes

    USGS Publications Warehouse

    Stanley, Jon G.; Eshenroder, Randy L.; Hartman, Wilbur L.

    1987-01-01

    Populations of lake trout, severely depleted in Lake Superior and virtually extirpated from the other Great Lakes because of sea lamprey predation and intense fishing, are now maintained by annual plantings of hatchery-reared fish in Lakes Michigan, Huron, and Ontario and parts of Lake Superior. The extensive coastal areas of the Great Lakes and proximity to large populations resulted in fishing pressure on planted lake trout heavy enough to push annual mortality associated with sport and commercial fisheries well above the critical level needed to reestablish self-sustaining stocks. The interagency, international program for rehabilitating lake trout includes controlling sea lamprey abundance, stocking hatchery-reared lake trout, managing the catch, and establishing sanctuaries where harvest is prohibited. Three lake trout sanctuaries have been established in Lake Michigan: the Fox Island Sanctuary of 121, 500 ha, in the Chippewa-Ottawa Treaty fishing zone in the northern region of the lake; the Milwaukee Reef Sanctuary of 160, 000 ha in midlake, in boundary waters of Michigan and Wisconsin; and Julian's Reef Sanctuary of 6, 500 ha, in Illinois waters. In northern Lake Huron, Drummond Island Sanctuary of 55, 000 ha is two thirds in Indian treaty-ceded waters in Michigan and one third in Ontario waters of Canada. A second sanctuary, Six Fathom Bank-Yankee Reef Sanctuary, in central Lake Huron contains 168, 000 ha. Sanctuary status for the Canadian areas remains to be approved by the Provincial government. In Lake Superior, sanctuaries protect the spawning grounds of Gull Island Shoal (70, 000 ha) and Devils Island Shoal (44, 000 ha) in Wisconsin's Apostle Island area. These seven sanctuaries, established by the several States and agreed upon by the States, Indian tribes, the U.S. Department of the Interior, and the Province of Ontario, contribute toward solving an interjurisdictional fishery problem.

  5. Water quality of Lake Austin and Town Lake, Austin, Texas

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Andrews, F.L.; Wells, F.C.; Shelby, W.J.

    1988-01-01

    Lake Austin and Town Lake are impoundments on the Colorado River in Travis County, central Texas, and are a source of water for municipal industrial water supplies, electrical-power generation, and recreation for more than 500,000 people in the Austin metropolitan area. Small vertical temperature variations in both lakes were attributed to shallow depths in the lakes and short retention times of water in the lakes during the summer months. The largest areal variations in dissolved oxygen generally occur in Lake Austin during the summer as a result of releases of water from below the thermocline in Lake Travis. Except formore » iron, manganese, and mercury, dissolved concentrations of trace elements in water collected from Lake Austin and Town Lake did not exceed the primary or secondary drinking water standards set by the US Environmental Protection Agency. Little or no effect of stormwater runoff on temperature, dissolved oxygen, or minor elements could be detected in either Lake Austin or Town Lake. Little seasonal or areal variation was noted in nitrogen concentrations in Lake Austin or Town lake. Total phosphorus concentrations generally were small in both lakes. Increased concentrations of nitrogen and phosphorus were detected after storm runoff inflow in Town Lake, but not in Lake Austin; densities of fecal-coliform bacteria increased in Lake Austin and Town Lake, but were substantially greater in Town Lake than in Lake Austin. 18 refs., 38 figs., 59 tabs.« less

  6. Stroke in Switzerland: social determinants of treatment access and cost of illness.

    PubMed

    Snozzi, Philippe; Blank, Patricia R; Szucs, Thomas D

    2014-01-01

    Few useful empirical data on stroke are available for Switzerland. The aim of this study was to collect data on the use of medical resources and associated costs among stroke patients. Special attention was paid to possible correlations between epidemiologic indicators, sociodemographic variables, resource use, and costs. We carried out a representative population survey of 19,123 households in the German- and French-speaking parts of Switzerland with computer-assisted telephone interviews in 2005. Detailed sociodemographic data and information on the use of resources were collected from 509 individuals aged 15-75 years who had cared for a stroke patient in the past 1-2 years. In the last 1-2 years, a total of 7.8% of households were affected by stroke in the German-speaking part of Switzerland, whereas only 4.3% of households were affected in the French-speaking part of Switzerland (odds ratio [OR] = 1.89, P < .001). Based on the length of stay, the total cost of inpatient treatment and rehabilitation during the average 1-year observation period was estimated at €40,090. Stroke therefore caused approximately 2.9% of all inpatient costs in Switzerland. Patients with supplementary insurance were treated more frequently as inpatients than patients with statutory insurance (OR: 2.14, P = .014), and patients with a low household income were referred less frequently to an inpatient rehabilitation facility than those with medium or high household income (OR = .58, P < .05). This survey confirms the medical and economic importance of stroke and supplements the existing European data. Further research is needed in regard to incidence differences in stroke across Switzerland. Patients without supplementary insurance or with low household income were less likely to receive inpatient treatment. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  7. Evidence of offshore lake trout reproduction in Lake Huron

    USGS Publications Warehouse

    DeSorcie, Timothy J.; Bowen, Charles A.

    2003-01-01

    Six Fathom Bank-Yankee Reef, an offshore reef complex, was an historically important spawning area believed to represent some of the best habitat for the rehabilitation of lake trout Salvelinus namaycush in Lake Huron. Since 1986, lake trout have been stocked on these offshore reefs to reestablish self-sustaining populations. We sampled with beam trawls to determine the abundance of naturally reproduced age-0 lake trout on these offshore reefs during May-July in 1994-1998 and 2000-2002. In total, 123 naturally reproduced lake trout fry were caught at Six Fathom Bank, and 2 naturally reproduced lake trout fry were caught at nearby Yankee Reef. Our findings suggest that this region of Lake Huron contains suitable habitat for lake trout spawning and offers hope that lake trout rehabilitation can be achieved in the main basin of Lake Huron.

  8. Gun utopias? Firearm access and ownership in Israel and Switzerland

    PubMed Central

    Rosenbaum, Janet

    2011-01-01

    The 2011 attempted assassination of a US representative renewed the national gun control debate. Gun advocates claim that mass-casualty events are mitigated and deterred with three policies: (1) permissive gun laws, (2) widespread gun ownership, (3) encouragement of armed civilians who can intercept shooters, and cite Switzerland and Israel as exemplars. We evaluate these claims with analysis of International Crime Victimization Survey (ICVS) data and translation of laws and original source material. Swiss and Israeli laws limit firearm ownership and require permit renewal 14 times annually. ICVS analysis finds that the US has more firearms per capita and per household than either country. Switzerland and Israel curtail off-duty soldiers firearm access to prevent firearm deaths. Suicide among soldiers decreased by 40% after the Israeli armys 2006 reforms. Compared with the US, Switzerland and Israel have lower gun ownership and stricter gun laws, and their policies discourage personal gun ownership. PMID:22089893

  9. Gun utopias? Firearm access and ownership in Israel and Switzerland.

    PubMed

    Rosenbaum, Janet E

    2012-02-01

    The 2011 attempted assassination of a US representative renewed the national gun control debate. Gun advocates claim mass-casualty events are mitigated and deterred with three policies: (a) permissive gun laws, (b) widespread gun ownership, (c) and encouragement of armed civilians who can intercept shooters. They cite Switzerland and Israel as exemplars. We evaluate these claims with analysis of International Crime Victimization Survey (ICVS) data and translation of laws and original source material. Swiss and Israeli laws limit firearm ownership and require permit renewal one to four times annually. ICVS analysis finds the United States has more firearms per capita and per household than either country. Switzerland and Israel curtail off-duty soldiers' firearm access to prevent firearm deaths. Suicide among soldiers decreased by 40 per cent after the Israeli army's 2006 reforms. Compared with the United States, Switzerland and Israel have lower gun ownership and stricter gun laws, and their policies discourage personal gun ownership.

  10. Lake Nasser and Toshka Lakes, Egypt

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Lake Nasser (center) and the Toshka Lakes (center left) glow emerald green and black in this MODIS true-color image acquired March 8, 2002. Located on and near the border of Egypt and Norther Sudan, these lakes are an oasis of water in between the Nubian (lower right) and Libyan Deserts (upper left). Also visible are the Red Sea (in the upper right) and the Nile River (running north from Lake Nasser). Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  11. Homicide-suicide cases in Switzerland and their impact on the Swiss Weapon Law.

    PubMed

    Grabherr, Silke; Johner, Stephan; Dilitz, Carine; Buck, Ursula; Killias, Martin; Mangin, Patrice; Plattner, Thomas

    2010-12-01

    Homicide followed by the suicide of the offender is a well-known phenomenon. In most cases, it takes place in the context of the so-called "family tragedies." A recent series of such family tragedies in Switzerland prompted an intensive debate in the media and the Swiss government concerning the Swiss Weapon Law, in particular the requirement to keep personal army weapons at home. The present study of Homicide-Suicide cases in Switzerland, thus focuses on the role played by guns, especially military weapons, in such crimes. We investigated retrospectively 75 cases of Homicide-Suicide, comprising 172 individuals and spanning a period of 23 years in western and central Switzerland. Our results show that if guns were used in 76% of the cases, army weapons were the cause of death in 25% of the total. In 28% of the deaths caused by a gunshot, the exact type of the gun and its origin could not be determined. Thus, the majority of Homicide-Suicide cases in Switzerland involve the use of guns. The exact percentage of cases were military weapons were involved could not be defined. In our opinion, a stricter weapons law, restricting access to firearms, would be a factor of prevention of Homicide- Suicide cases in Switzerland.

  12. Lake whitefish diet, condition, and energy density in Lake Champlain and the lower four Great Lakes following dreissenid invasions

    USGS Publications Warehouse

    Herbst, Seth J.; Marsden, J. Ellen; Lantry, Brian F.

    2013-01-01

    Lake Whitefish Coregonus clupeaformis support some of the most valuable commercial freshwater fisheries in North America. Recent growth and condition decreases in Lake Whitefish populations in the Great Lakes have been attributed to the invasion of the dreissenid mussels, zebra mussels Dreissena polymorpha and quagga mussels D. bugensis, and the subsequent collapse of the amphipod, Diporeia, a once-abundant high energy prey source. Since 1993, Lake Champlain has also experienced the invasion and proliferation of zebra mussels, but in contrast to the Great Lakes, Diporeia were not historically abundant. We compared the diet, condition, and energy density of Lake Whitefish from Lake Champlain after the dreissenid mussel invasion to values for those of Lake Whitefish from Lakes Michigan, Huron, Erie, and Ontario. Lake Whitefish were collected using gill nets and bottom trawls, and their diets were quantified seasonally. Condition was estimated using Fulton's condition factor (K) and by determining energy density. In contrast to Lake Whitefish from some of the Great Lakes, those from Lake Champlain Lake Whitefish did not show a dietary shift towards dreissenid mussels, but instead fed primarily on fish eggs in spring, Mysis diluviana in summer, and gastropods and sphaeriids in fall and winter. Along with these dietary differences, the condition and energy density of Lake Whitefish from Lake Champlain were high compared with those of Lake Whitefish from Lakes Michigan, Huron, and Ontario after the dreissenid invasion, and were similar to Lake Whitefish from Lake Erie; fish from Lakes Michigan, Huron, and Ontario consumed dreissenids, whereas fish from Lake Erie did not. Our comparisons of Lake Whitefish populations in Lake Champlain to those in the Great Lakes indicate that diet and condition of Lake Champlain Lake Whitefish were not negatively affected by the dreissenid mussel invasion.

  13. Spatial patterns in PCB concentrations of Lake Michigan lake trout

    USGS Publications Warehouse

    Madenjian, Charles P.; DeSorcie, Timothy J.; Stedman, Ralph M.; Brown, Edward H.; Eck, Gary W.; Schmidt, Larry J.; Hesselberg, Robert J.; Chernyak, Sergei M.; Passino-Reader, Dora R.

    1999-01-01

    Most of the PCB body burden in lake trout (Salvelinus namaycush) of the Great Lakes is from their food. PCB concentrations were determined in lake trout from three different locations in Lake Michigan during 1994–1995, and lake trout diets were analyzed at all three locations. The PCB concentrations were also determined in alewife (Alosa pseudoharengus), rainbow smelt (Osmerus mordax), bloater (Coregonus hoyi), slimy sculpin (Cottus cognatus), and deepwater sculpin (Myoxocephalus thompsoni), five species of prey fish eaten by lake trout in Lake Michigan, at three nearshore sites in the lake. Despite the lack of significant differences in the PCB concentrations of alewife, rainbow smelt, bloater, slimy sculpin, and deepwater sculpin from the southeastern nearshore site near Saugatuck (Michigan) compared with the corresponding PCB concentrations from the northwestern nearshore site near Sturgeon Bay (Wisconsin), PCB concentrations in lake trout at Saugatuck were significantly higher than those at Sturgeon Bay. The difference in the lake trout PCB concentrations between Saugatuck and Sturgeon Bay could be explained by diet differences. The diet of lake trout at Saugatuck was more concentrated in PCBs than the diet of Sturgeon Bay lake trout, and therefore lake trout at Saugatuck were more contaminated in PCBs than Sturgeon Bay lake trout. These findings were useful in interpreting the long-term monitoring series for contaminants in lake trout at both Saugatuck and the Wisconsin side of the lake.

  14. Potential strategies for recovery of lake whitefish and lake herring stocks in eastern Lake Erie

    USGS Publications Warehouse

    Oldenburg, K.; Stapanian, M.A.; Ryan, P.A.; Holm, E.

    2007-01-01

    Lake Erie sustained large populations of ciscoes (Salmonidae: Coregoninae) 120 years ago. By the end of the 19th century, abundance of lake whitefish (Coregonus clupeaformis) had declined drastically. By 1925, the lake herring (a cisco) population (Coregonus artedii) had collapsed, although a limited lake herring fishery persisted in the eastern basin until the 1950s. In the latter part of the 20th century, the composition of the fish community changed as oligotrophication proceeded. Since 1984, a limited recovery of lake whitefish has occurred, however no recovery was evident for lake herring. Current ecological conditions in Lake Erie probably will not inhibit recovery of the coregonine species. Recovery of walleye (Sander vitreus) and efforts to rehabilitate the native lake trout (Salvelinus namaycush) in Lake Erie will probably assist recovery because these piscivores reduce populations of alewife (Alosa psuedoharengus) and rainbow smelt (Osmerus mordax), which inhibit reproductive success of coregonines. Although there are considerable spawning substrates available to coregonine species in eastern Lake Erie, eggs and fry would probably be displaced by storm surge from most shoals. Site selection for stocking or seeding of eggs should consider the reproductive life cycle of the stocked fish and suitable protection from storm events. Two potential sites in the eastern basin have been identified. Recommended management procedures, including commercial fisheries, are suggested to assist in recovery. Stocking in the eastern basin of Lake Erie is recommended for both species, as conditions are adequate and the native spawning population in the eastern basin is low. For lake herring, consideration should be given to match ecophenotypes as much as possible. Egg seeding is recommended. Egg seeding of lake whitefish should be considered initially, with fingerling or yearling stocking suggested if unsuccessful. Spawning stocks of whitefish in the western basin of Lake

  15. Glacial lake inventory and lake outburst potential in Uzbekistan.

    PubMed

    Petrov, Maxim A; Sabitov, Timur Y; Tomashevskaya, Irina G; Glazirin, Gleb E; Chernomorets, Sergey S; Savernyuk, Elena A; Tutubalina, Olga V; Petrakov, Dmitriy A; Sokolov, Leonid S; Dokukin, Mikhail D; Mountrakis, Giorgos; Ruiz-Villanueva, Virginia; Stoffel, Markus

    2017-08-15

    Climate change has been shown to increase the number of mountain lakes across various mountain ranges in the World. In Central Asia, and in particular on the territory of Uzbekistan, a detailed assessment of glacier lakes and their evolution over time is, however lacking. For this reason we created the first detailed inventory of mountain lakes of Uzbekistan based on recent (2002-2014) satellite observations using WorldView-2, SPOT5, and IKONOS imagery with a spatial resolution from 2 to 10m. This record was complemented with data from field studies of the last 50years. The previous data were mostly in the form of inventories of lakes, available in Soviet archives, and primarily included localized in-situ data. The inventory of mountain lakes presented here, by contrast, includes an overview of all lakes of the territory of Uzbekistan. Lakes were considered if they were located at altitudes above 1500m and if lakes had an area exceeding 100m 2 . As in other mountain regions of the World, the ongoing increase of air temperatures has led to an increase in lake number and area. Moreover, the frequency and overall number of lake outburst events have been on the rise as well. Therefore, we also present the first outburst assessment with an updated version of well-known approaches considering local climate features and event histories. As a result, out of the 242 lakes identified on the territory of Uzbekistan, 15% are considered prone to outburst, 10% of these lakes have been assigned low outburst potential and the remainder of the lakes have an average level of outburst potential. We conclude that the distribution of lakes by elevation shows a significant influence on lake area and hazard potential. No significant differences, by contrast, exist between the distribution of lake area, outburst potential, and lake location with respect to glaciers by regions. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Progress toward lake trout restoration in Lake Michigan

    USGS Publications Warehouse

    Holey, Mark E.; Rybicki, Ronald W.; Eck, Gary W.; Brown, Edward H.; Marsden, J. Ellen; Lavis, Dennis S.; Toneys, Michael L.; Trudeau, Tom N.; Horrall, Ross M.

    1995-01-01

    Progress toward lake trout restoration in Lake Michigan is described through 1993. Extinction of the native lake trout fishery by sea lamprey predation, augmented by exploitation and habitat destruction, resulted in an extensive stocking program of hatchery-reared lake trout that began in 1965. Sea lamprey abundance was effectively controlled using selective chemical toxicants. The initial stocking produced a measurable wild year class of lake trout by 1976 in Grand Traverse Bay, but failed to continue probably due to excessive exploitation. The overall lack of successful reproduction lakewide by the late 1970s led to the development and implementation in 1985 of a focused inter-agency lakewide restoration plan by a technical committee created through the Lake Committee structure of the Great Lakes Fishery Commission. Strategies implemented in 1985 by the plan included setting a 40% total mortality goal lakewide, creating two large refuges designed to encompass historically the most productive spawning habitat and protect trout stocked over their home range, evaluating several lake trout strains, and setting stocking priorities throughout the lake. Target levels for stocking in the 1985 Plan have never been reached, and are much less than the estimated lakewide recruitment of yearlings by the native lake trout stocks. Since 1985, over 90% of the available lake trout have been stocked over the best spawning habitat, and colonization of the historically productive offshore reefs has occurred. Concentrations of spawning lake trout large enough for successful reproduction, based on observations of successful hatchery and wild stocks, have developed at specific reefs. Continued lack of recruitment at these specific sites suggests that something other than stotk abundance has limited success. Poor survival of lake trout eggs, assumed to be related to contaminant burden, occurred in the late 1970s and early 1980s, but survival has since increased to equal survival in the

  17. [The nutritional status in Switzerland--consequences for prevention].

    PubMed

    Eichholzer, M; Gutzwiller, F

    1997-08-30

    Diet is of importance in the prevention of most chronic diseases. Dietary habits are measured regularly in most countries. In Switzerland data on groups and individuals are available, but a comprehensive dietary survey is still lacking. Since World War II an overall decrease in foods rich in complex carbohydrates and an increase in foods rich in fat available per capita of the population has been observed. Data on individuals show that 30%, i.e. 39% of men and 22% of women, in Switzerland are over-weight (BMI < or = 25). The percentages of energy intake as fat and sugar are higher, and the percentage of energy intake as complex carbohydrates lower than recommended. 7% of women and 6% of men consume hazardous amounts of alcohol (men > or = 60 g/day, women > or = 20 g/day). Marginal vitamin deficiencies are observed in various population groups for the vitamins B1, B2, B6, folic acid and vitamin C. Due to the fortification of salt and the widespread use of American wheat rich in selenium, iodine and selenium intake can be considered adequate. An insufficient intake of calcium is demonstrated in the elderly and an insufficient intake of calcium and iron in women. As a consequence of this nutritional situation, the first national nutritional guidelines have recently been published in Switzerland.

  18. Microclimate and the zoonotic cycle of tick-borne encephalitis virus in Switzerland.

    PubMed

    Burri, C; Bastic, V; Maeder, G; Patalas, E; Gern, L

    2011-05-01

    The focal distribution of tick-borne encephalitis virus (TBEV; Flaviviridae, Flavivirus) appears to depend mainly on cofeeding transmission between infected Ixodes ricinus L. nymphs and uninfected larvae. To better understand the role of cofeeding ticks in the transmission of TBEV, we investigated tick infestation of rodents and the influence of microclimate on the seasonality of questing I. ricinus ticks. A 3-yr study was carried out at four sites, including two confirmed TBEV foci. Free-living ticks and rodents were collected monthly, and microclimatic data were recorded. A decrease in questing nymph density was observed in 2007, associated with low relative humidity and high temperatures in spring. One site, Thun, did not show this decrease, probably because of microclimatic conditions in spring that favored the questing nymph population. During the same year, the proportion of rodents carrying cofeeding ticks was lower at sites where the questing nymph density decreased, although the proportion of infested hosts was similar among years. TBEV was detected in 0.1% of questing ticks, and in 8.6 and 50.0% of larval ticks feeding on two rodents. TBEV was detected at all but one site, where the proportion of hosts with cofeeding ticks was the lowest. The proportion of hosts with cofeeding ticks seemed to be one of the factors that distinguished a TBEV focus from a non-TBEV focus. The enzootic cycle of TBEV might be disrupted when dry and hot springs occur during consecutive years.

  19. Lake trout rehabilitation in Lake Huron

    USGS Publications Warehouse

    Eshenroder, Randy L.; Payne, N. Robert; Johnson, James E.; Bowen, Charles; Ebener, Mark P.

    1995-01-01

    Efforts to restore lake trout (Salvelinus namaycush) in Lake Huron after their collapse in the 1940s were underway in the early 1970s with completion of the first round of lampricide applications in tributary streams and the stocking of several genotypes. We assess results of rehabilitation and establish a historical basis for comparison by quantifying the catch of spawning lake trout from Michigan waters in 1929-1932. Sixty-eight percent of this catch occurred in northern waters (MH-1) and most of the rest (15%) was from remote reefs in the middle of the main basin. Sea lampreys (Petromyzon marinus) increased in the early 1980s in the main basin and depressed spawning populations of lake trout. This increase was especially severe in northern waters and appeared to be associated with untreated populations in the St. Marys River. Excessive commercial fishing stemming from unresolved treaty rights also contributed to loss of spawning fish in northern Michigan waters. Seneca-strain lake trout did not appear to be attacked by sea lampreys until they reached a size > 532 mm. At sizes > 632 mm, Seneca trout were 40-fold more abundant than the Marquette strain in matched-planting experiments. Natural reproduction past the fry stage has occurred in Thunder Bay and South Bay, but prospects for self-sustaining populations of lake trout in the main basin are poor because sea lampreys are too abundant, only one side of the basin is stocked, and stocking is deferred to allow commercial gillnetting in areas where most of the spawning occurred historically. Backcross lake trout, a lake trout x splake (s. Fontinalis x s. Namaycush) hybrid, did not reproduce in Georgian Bay, but this genotype is being replaced with pure-strain lake trout, whose early performance appears promising.

  20. Evolution of alkaline lakes - Lake Van case study

    NASA Astrophysics Data System (ADS)

    Tillman Meyer, Felix; Viehberg, Finn; Bahroun, Sonya; Wolf, Annabel; Immenhauser, Adrian; Kwiecien, Ola

    2017-04-01

    Lake Van in Eastern Anatolia (Turkey) is the largest terminal soda lake on Earth. The lake sedimentary profile covers ca. 600 ka (Stockhecke et al. 2014) Based on lithological changes, the presence of freshwater microfossils and close-to-freshwater pH value in the pore water, members of ICDP PALEOVAN concluded that Lake Van might have started as an open lake. Here we show paleontological and geochemical evidence in favour of this idea and constrain the time, when Lake Van likely transformed into a closed lake. Additionally we provide the first conceptual model of how this closure may have happened. Our archives of choice are inorganic and biogenic carbonates, separated by wet sieving. We identified microfossil assemblages (fraction > 125 µm) and performed high-resolution oxygen isotope (delta18O) and elemental (Mg/Ca, Sr/Ca) analyses of the fraction < 63 µm assuming that it represents only carbonates precipitating in the water column. Microfossil assemblage consists of three different species of ostracods (Candona spp, Loxoconcha sp, Amnicythere spp.), diatoms, gastropods and bivalves. Brakish-water ostracods, Loxoconcha sp and Amnicythere sp occur more often after 530 ka. Additionaly, Loxoconcha sp is a shallow-water species relaying on plants growing in the photic zone as food supply. These two aspects point to an increasing salinity in a shallowing lake. The delta18O values of inorganic carbonates are relatively low during the initial phase of Lake Van and increase abruptly (ca. 7‰) after 530 ka BP. At approximately the same time combination of Sr/Ca and Mg/Ca data suggest first occurrence of aragonite. Again, these findings suggest geochemical changes of the lake water concurrent with transition documented by microfossils. Comparison between Lake Van and Lake Ohrid (Lacey et al. 2016) delta18O data, precludes regional climate change (e.g.: increased evaporation) as the main driver of observed changes. With no evidence for increased volcanic or tectonic

  1. Embryotoxicity of an extract from Great Lakes lake trout to rainbow trout and lake trout

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wright, P.J.; Tillitt, D.E.

    1995-12-31

    Aquatic ecosystems such as the Great Lakes are known to be contaminated with chemicals that are toxic to fish. However, the role of these contaminants in reproductive failures of fishes, such as lake trout recruitment, has remained controvertible. It was the objective to evaluate dioxin-like embryotoxicity of a complex mixture of chemicals and predict their potential to cause the lack of recruitment in Great Lakes lake trout. Graded doses of a complex environmental extract were injected into eggs of both rainbow trout and lake trout. The extract was obtained from whole adult lake trout collected from Lake Michigan in 1988.more » The extract was embryotoxic in rainbow trout, with LD50 values for Arlee strain and Erwin strain of 33 eggEQ and 14 eggEQ respectively. The LOAEL for hemorrhaging, yolk-sac edema, and craniofacial deformities in rainbow trout were 2, 2, and 4 eggEQ, respectively. Subsequent injections of the extract into lake trout eggs were likewise embryotoxic, with an LD50 value of 7 eggEQ. The LOAEL values for the extract in lake trout for hemorrhaging, yolk-sac edema, and craniofacial deformities were 0.1, 1, and 2 eggEQ, respectively. The current levels of contaminants in lake trout eggs are above the threshold for hemorrhaging and yolk-sac edema. The results also support the use of an additive model of toxicity to quantify PCDDs, PCDFs, Non-o-PCBs, and Mono-o-PCBs in relation to early life stage mortality in Lake Michigan lake trout.« less

  2. Prevalence of Diphyllobothrium latum (Cestoda: Diphyllobothriidae) plerocercoids in fish species from four Italian lakes and risk for the consumers.

    PubMed

    Gustinelli, Andrea; Menconi, Vasco; Prearo, Marino; Caffara, Monica; Righetti, Marzia; Scanzio, Tommaso; Raglio, Annibale; Fioravanti, Maria Letizia

    2016-10-17

    In recent years there has been a re-emergence of diphyllobothriasis by Diphyllobothrium latum (Cestoda: Diphyllobothriidae) in Italy, France and Switzerland, where in the past this fish-borne zoonosis was widespread and then virtually disappeared. A change in eating habits such as the consumption of raw/undercooked freshwater fish, has led to an increased risk for consumers of ingesting infective larvae of D. latum. A survey on the factors responsible for the re-emergence of human diphyllobothriasis in Italy was carried out from March 2013 to December 2014. The aim of this study was to assess the diffusion of D. latum plerocercoids in the fish populations of the sub-alpine lakes of Maggiore, Como, Iseo and Garda, updating the scarce historical data and assessing a preliminary "risk level" of the lacustrine environments and fish species under investigation. A total of 2228 fish belonging to 5 species, 690 from Lake Maggiore, 500 from Lake Como, 655 from Lake Iseo and 383 from Lake Garda were submitted to parasitological examination. The presence of D. latum plerocercoid larvae was detected in 6.6%, 25.4% and 7.6% of perch (Perca fluviatilis) from Lakes Maggiore, Como and Iseo respectively. The parasite was also present in pike (Esox lucius) with prevalence values ranging from 71.4 to 84.2% and in 3.6-3.8% of burbot (Lota lota) from Lakes Iseo and Como. Fish from Lake Garda were negative as well as sampled whitefish (Coregonus lavaretus) and shad (Alosa fallax lacustris). The results of this survey showed a widespread presence of D. latum plerocercoid larvae in Maggiore, Como and Iseo fish populations. Urban fecal contamination of water is still a key issue to be resolved, together with the improvement of communication with consumers regarding the best dietary habits and the most effective processes of parasite inactivation, required for the consumption of raw/undercooked fish caught in high-risk areas. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Hydrogeologic Controls on Lake Level at Mountain Lake, Virginia

    NASA Astrophysics Data System (ADS)

    Roningen, J. M.; Burbey, T. J.

    2011-12-01

    Mountain Lake in Giles County, Virginia has a documented history of severe natural lake-level changes involving groundwater seepage that extend over the past 4200 years. Featured in the 1986 movie Dirty Dancing, the natural lake dried up completely in September 2008 and levels have not yet recovered. A hydrogeologic investigation was undertaken in an effort to determine the factors influencing lake level changes. A daily water balance, dipole-dipole electrical resistivity surveying, well logging and chemical sampling have shed light on: 1) the influence of a fault not previously discussed in literature regarding the lake, 2) the seasonal response to precipitation of a forested first-order drainage system in fractured rock, and 3) the possibility of flow pathways related to karst features. Geologic controls on lake level were investigated using several techniques. Geophysical surveys using dipole-dipole resistivity located possible subsurface flowpaths both to and from the lake. Well logs, lineament analysis, and joint sampling were used to assess structural controls on lake hydrology. Major ions were sampled at wells, springs, streams, and the lake to evaluate possible mixing of different sources of water in the lake. Groundwater levels were monitored for correlation to lake levels, rainfall events, and possible seismic effects. The hydrology of the lake was quantified with a water balance on a daily time step. Results from the water balance indicate steady net drainage and significant recharge when vegetation is dormant, particularly during rain-on-snow melt events. The resistivity survey reveals discrete areas that represent flow pathways from the lake, as well as flowpaths to springs upgradient of the lake located in the vicinity of the fault. The survey also suggests that some flowpaths may originate outside of the topographic watershed of the lake. Chemical evidence indicates karst may underlie the lakebed. Historical data suggest that artificial intervention

  4. Lake-level frequency analysis for Devils Lake, North Dakota

    USGS Publications Warehouse

    Wiche, Gregg J.; Vecchia, Aldo V.

    1996-01-01

    Two approaches were used to estimate future lake-level probabilities for Devils Lake. The first approach is based on an annual lake-volume model, and the second approach is based on a statistical water mass-balance model that generates seasonal lake volumes on the basis of seasonal precipitation, evaporation, and inflow. Autoregressive moving average models were used to model the annual mean lake volume and the difference between the annual maximum lake volume and the annual mean lake volume. Residuals from both models were determined to be uncorrelated with zero mean and constant variance. However, a nonlinear relation between the residuals of the two models was included in the final annual lakevolume model.Because of high autocorrelation in the annual lake levels of Devils Lake, the annual lake-volume model was verified using annual lake-level changes. The annual lake-volume model closely reproduced the statistics of the recorded lake-level changes for 1901-93 except for the skewness coefficient. However, the model output is less skewed than the data indicate because of some unrealistically large lake-level declines. The statistical water mass-balance model requires as inputs seasonal precipitation, evaporation, and inflow data for Devils Lake. Analysis of annual precipitation, evaporation, and inflow data for 1950-93 revealed no significant trends or long-range dependence so the input time series were assumed to be stationary and short-range dependent.Normality transformations were used to approximately maintain the marginal probability distributions; and a multivariate, periodic autoregressive model was used to reproduce the correlation structure. Each of the coefficients in the model is significantly different from zero at the 5-percent significance level. Coefficients relating spring inflow from one year to spring and fall inflows from the previous year had the largest effect on the lake-level frequency analysis.Inclusion of parameter uncertainty in the model

  5. Lake-level frequency analysis for Devils Lake, North Dakota

    USGS Publications Warehouse

    Wiche, Gregg J.; Vecchia, Aldo V.

    1995-01-01

    Two approaches were used to estimate future lake-level probabilities for Devils Lake. The first approach is based on an annual lake-volume model, and the second approach is based on a statistical water mass-balance model that generates seasonal lake volumes on the basis of seasonal precipitation, evaporation, and inflow.Autoregressive moving average models were used to model the annual mean lake volume and the difference between the annual maximum lake volume and the annual mean lake volume. Residuals from both models were determined to be uncorrelated with zero mean and constant variance. However, a nonlinear relation between the residuals of the two models was included in the final annual lake-volume model.Because of high autocorrelation in the annual lake levels of Devils Lake, the annual lakevolume model was verified using annual lake-level changes. The annual lake-volume model closely reproduced the statistics of the recorded lake-level changes for 1901-93 except for the skewness coefficient However, the model output is less skewed than the data indicate because of some unrealistically large lake-level declines.The statistical water mass-balance model requires as inputs seasonal precipitation, evaporation, and inflow data for Devils Lake. Analysis of annual precipitation, evaporation, and inflow data for 1950-93 revealed no significant trends or long-range dependence so the input time series were assumed to be stationary and short-range dependent.Normality transformations were used to approximately maintain the marginal probability distributions; and a multivariate, periodic autoregressive model was used to reproduce the correlation structure. Each of the coefficients in the model is significantly different from zero at the 5-percent significance level. Coefficients relating spring inflow from one year to spring and fall inflows from the previous year had the largest effect on the lake-level frequency analysis.Inclusion of parameter uncertainty in the model

  6. Lake trout in northern Lake Huron spawn on submerged drumlins

    USGS Publications Warehouse

    Riley, Stephen C.; Binder, Thomas; Wattrus, Nigel J.; Faust, Matthew D.; Janssen, John; Menzies, John; Marsden, J. Ellen; Ebener, Mark P.; Bronte, Charles R.; He, Ji X.; Tucker, Taaja R.; Hansen, Michael J.; Thompson, Henry T.; Muir, Andrew M.; Krueger, Charles C.

    2014-01-01

    Recent observations of spawning lake trout Salvelinus namaycush near Drummond Island in northern Lake Huron indicate that lake trout use drumlins, landforms created in subglacial environments by the action of ice sheets, as a primary spawning habitat. From these observations, we generated a hypothesis that may in part explain locations chosen by lake trout for spawning. Most salmonines spawn in streams where they rely on streamflows to sort and clean sediments to create good spawning habitat. Flows sufficient to sort larger sediment sizes are generally lacking in lakes, but some glacial bedforms contain large pockets of sorted sediments that can provide the interstitial spaces necessary for lake trout egg incubation, particularly if these bedforms are situated such that lake currents can penetrate these sediments. We hypothesize that sediment inclusions from glacial scavenging and sediment sorting that occurred during the creation of bedforms such as drumlins, end moraines, and eskers create suitable conditions for lake trout egg incubation, particularly where these bedforms interact with lake currents to remove fine sediments. Further, these bedforms may provide high-quality lake trout spawning habitat at many locations in the Great Lakes and may be especially important along the southern edge of the range of the species. A better understanding of the role of glacially-derived bedforms in the creation of lake trout spawning habitat may help develop powerful predictors of lake trout spawning locations, provide insight into the evolution of unique spawning behaviors by lake trout, and aid in lake trout restoration in the Great Lakes.

  7. Sports-related sudden cardiac deaths in the young population of Switzerland.

    PubMed

    Asatryan, Babken; Vital, Cristina; Kellerhals, Christoph; Medeiros-Domingo, Argelia; Gräni, Christoph; Trachsel, Lukas D; Schmied, Christian M; Saguner, Ardan M; Eser, Prisca; Herzig, David; Bolliger, Stephan; Michaud, Katarzyna; Wilhelm, Matthias

    2017-01-01

    In Switzerland, ECG screening was first recommended for national squad athletes in 1998. Since 2001 it has become mandatory in selected high-risk professional sports. Its impact on the rates of sports-related sudden cardiac death (SCD) is unknown. We aimed to study the incidence, causes and time trends of sports-related SCD in comparison to SCD unrelated to exercise in Switzerland. We reviewed all forensic reports of SCDs of the German-speaking region of Switzerland in the age group of 10 to 39 years, occurring between 1999 and 2010. Cases were classified into three categories based on whether or not deaths were associated with sports: no sports (NONE), recreational sports (REC), and competitive sports (COMP). Over the 12-year study period, 349 SCD cases were recorded (mean age 30±7 years, 76.5% male); 297 cases were categorized as NONE, 31 as REC, and 21 as COMP. Incidences of SCD per 100,000 person-years [mean (95% CI)] were the lowest in REC [0.43 (0.35-0.56)], followed by COMP [1.19 (0.89-1.60)] and NONE [2.46 (2.27-2.66)]. In all three categories, coronary artery disease (CAD) with or without acute myocardial infarction (MI) was the most common cause of SCD. Three professional athletes were identified in COMP category which all had SCD due to acute MI. There were no time trends, neither in overall, nor in cause-specific incidences of SCD. The incidence of SCD in young individuals in Switzerland is low, both related and unrelated to sports. In regions, like Switzerland, where CAD is the leading cause of SCD associated with competitions, screening for cardiovascular risk factors in addition to the current PPS recommendations might be indicated to improve detection of silent CAD and further decrease the incidence of SCD.

  8. Lake sturgeon population characteristics in Rainy Lake, Minnesota and Ontario

    USGS Publications Warehouse

    Adams, W.E.; Kallemeyn, L.W.; Willis, D.W.

    2006-01-01

    Rainy Lake contains a native population of lake sturgeon Acipenser fulvescens that has been largely unstudied. The aims of this study were to document the population characteristics of lake sturgeon in Rainy Lake and to relate environmental factors to year-class strength for this population. Gill-netting efforts throughout the study resulted in the capture of 322 lake sturgeon, including 50 recaptures. Lake sturgeon in Rainy Lake was relatively plump and fast growing compared with a 32-population summary. Population samples were dominated by lake sturgeon between 110 and 150 cm total length. Age–structure analysis of the samples indicated few younger (<10 years) lake sturgeon, but the smallest gill net mesh size used for sampling was 102 mm (bar measure) and would not retain small sturgeon. Few lake sturgeon older than age 50 years were captured, and maximum age of sampled fish was 59 years. Few correlations existed between lake sturgeon year-class indices and both annual and monthly climate variables, except that mean June air temperature was positively correlated with year-class strength. Analysis of Rainy Lake water elevation and resulting lake sturgeon year-class strength indices across years yielded consistent but weak negative correlations between late April and early June, when spawning of lake sturgeon occurs. The baseline data collected in this study should allow Rainy Lake biologists to establish more specific research questions in the future.

  9. Tracing of the Rhône River within Lake Geneva using stable isotope composition of water

    NASA Astrophysics Data System (ADS)

    Cotte, Gabriel; Vennemann, Torsten

    2017-04-01

    interflow and the control of different wind conditions on the formation of resultant gyres of circulation within Lake Geneva. For example, an anticlockwise gyre forces Rhône River water to flow at intermediate depths towards the northern shore of the lake and a return interflow close to the southern shore of the lake. Isotopic mixing models coupled to physical hydrodynamic models of the lake will help constrain the flow paths of the Rhône. References Halder J., Decrouy L. & Vennemann T. 2013 : Mixing of Rhône River water in Lake Geneva (Switzerland-France) inferred from stable hydrogen and oxygen isotope profiles, Journal of Hydrology 477:152-164

  10. Estimating healthcare costs of acute gastroenteritis and human campylobacteriosis in Switzerland.

    PubMed

    Schmutz, C; Mäusezahl, D; Bless, P J; Hatz, C; Schwenkglenks, M; Urbinello, D

    2017-03-01

    Rising numbers of campylobacteriosis case notifications in Switzerland resulted in an increased attention to acute gastroenteritis (AG) in general. Patients with a laboratory-confirmed Campylobacter infection perceive their disease as severe and around 15% of these patients are hospitalized. This study aimed at estimating healthcare costs due to AG and campylobacteriosis in Switzerland. We used official health statistics, data from different studies and expert opinion for estimating individual treatment costs for patients with different illness severity and for extrapolating overall costs due to AG and campylobacteriosis. We estimated that total Swiss healthcare costs resulting from these diseases amount to €29-45 million annually. Data suggest that patients with AG consulting a physician without a stool diagnostic test account for €9·0-24·2 million, patients with a negative stool test result for Campylobacter spp. for €12·3 million, patients testing positive for Campylobacter spp. for €1·8 million and hospitalized campylobacteriosis patients for €6·5 million/year. Healthcare costs of campylobacteriosis are high and most likely increasing in Switzerland considering that campylobacteriosis case notifications steadily increased in the past decade. Costs and potential cost savings for the healthcare system should be considered when designing sectorial and cross-sectorial interventions to reduce the burden of human campylobacteriosis in Switzerland.

  11. One health in Switzerland: a visionary concept at a crossroads?

    PubMed

    Meisser, Andrea; Schelling, Esther; Zinsstag, Jakob

    2011-05-13

    One Health stands for the health of humans, animals and the environment. There is only one health in our entire ecosystem, and the equation for its promotion is in interdisciplinary cooperation. One Health benefits from synergies to generate added value and is a promising strategy to strengthen health systems. A growing number of One Health conferences worldwide bear witness to a spirit of optimism which should result in the implementation of a sustainable One Health policy globally, regionally, nationally and locally. The purpose of this study was to investigate the opportunities for implementation of the One Health concept in Switzerland. Between April and August 2010, semi-structured face-to-face interviews were conducted with 16 key experts selected from among the leading personalities in the Swiss health system. The experts confirmed the potential of the One Health concept for Switzerland. Barriers such as cultural differences, absence of evidence, federal structures and a relatively low degree of suffering were identified and a road map established, including research activities, capacity-building and a stakeholder approach to joint preparation and tailored implementation of the One Health concept in Switzerland. These data suggest that One Health can support the opinion leaders in their quest for solutions. The detailed and unbiased description of potential barriers and a clear guide for a step-by-step action plan represent suggestions for a realistic way forward. Experience gained and lessons learnt in Switzerland may be of interest to other countries and help communicate and promote the One Health concept.

  12. Time trends in avoidable cancer mortality in Switzerland and neighbouring European countries 1996-2010.

    PubMed

    Feller, Anita; Mark, Michael Thomas; Steiner, Annik; Clough-Gorr, Kerri M

    2015-01-01

    What are the trends in avoidable cancer mortality in Switzerland and neighbouring countries? Mortality data and population estimates 1996-2010 were obtained from the Swiss Federal Statistical Office for Switzerland and the World Health Organization Mortality Database (http://www.who.int/healthinfo/mortality_data/en/) for Austria, Germany, France and Italy. Age standardised mortality rates (ASMRs, European standard) per 100 000 person-years were calculated for the population <75 years old by sex for the following groups of cancer deaths: (1) avoidable through primary prevention; (2) avoidable through early detection and treatment; (3) avoidable through improved treatment and medical care; and (4) remaining cancer deaths. To assess time trends in ASMRs, estimated annual percentage changes (EAPCs) with 95% confidence intervals (95% CIs) were calculated. In Switzerland and neighbouring countries cancer mortality in persons <75 years old continuously decreased 1996-2010. Avoidable cancer mortality decreased in all groups of avoidable cancer deaths in both sexes, with one exception. ASMRs for causes avoidable through primary prevention increased in females in all countries (in Switzerland from 16.2 to 20.3 per 100 000 person years, EAPC 2.0 [95% CI 1.4 to 2.6]). Compared with its neighbouring countries, Switzerland showed the lowest rates for all groups of avoidable cancer mortality in males 2008-2010. Overall avoidable cancer mortality decreased, indicating achievements in cancer care and related health policies. However, increasing trends in avoidable cancer mortality through primary prevention for females suggest there is a need in Switzerland and its European neighbouring countries to improve primary prevention.

  13. Lake Level Variation in Small Lakes: Not a Clear Picture

    NASA Astrophysics Data System (ADS)

    Starratt, S.

    2017-12-01

    Lake level is a useful tool for identifying regional changes in precipitation and evaporation. Due to the volume of water in large lakes, they may only record large-scale changes in water balance, while smaller lakes may record more subtle variations. However, the record of water level in small lakes is affected by a number of factors including elevation, bathymetry, nutrient load, and aquatic macrophyte abundance. The latest Quaternary diatom records from three small lakes with areas of <10 ha (Hobart Lake, OR, 1458 masl; Swamp Lake, CA, 1554 masl; Favre Lake, NV, 2899 masl) and a larger lake (Medicine Lake, CA, 2036 masl, 154 ha) were compared in this study. All the lakes have a deep central basin (>10 m) surrounded by a shallow (1-2 m) shelf. Changes in the abundance of diatoms representing different life habits (benthic, tychoplanktic, planktic) were used to identify lake level variation. Benthic taxa dominate the assemblage when only the central basin is occupied. As the shallow shelf is flooded, the abundance of tychoplanktic taxa increases. Planktic taxa increase with the establishment of stratification. Favre Lake presents the clearest indication of initial lake level rise (7600-5750 cal yr BP) and intermittent flooding of the shelf for the remainder of the record. Stratification appears to become established only in the last few hundred years. Higher nutrient levels in the early part of the Hobart Lake record lead to a nearly monotypic planktic assemblage which is replaced by a tychoplanktic-dominated assemblage as the lake floods the shelf at about 3500 cal yr BP. The last 500 years is dominated by benthic taxa associated with aquatic macrophytes. The consistent presence of planktic taxa in the Swamp Lake record suggests that the lake was stratified during most of its history, although slight variations in the relative abundances of planktic and tychoplanktic groups occur. The Medicine Lake record shows a gradual increase in planktic species between 11

  14. 78 FR 53675 - Safety Zone; Lake Erie Heritage Foundation, Battle of Lake Erie Reenactment; Lake Erie, Put-in...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-30

    ...-AA00 Safety Zone; Lake Erie Heritage Foundation, Battle of Lake Erie Reenactment; Lake Erie, Put-in-Bay... temporary safety zone in the waters of Lake Erie in the vicinity of Put-In-Bay, OH. This safety zone is intended to restrict vessels from a portion of Lake Erie during Battle of Lake Erie Reenactment near Put-In...

  15. Lake trout spawning habitat in the Six Fathom Bank-Yankee Reef lake trout sanctuary, Lake Huron

    USGS Publications Warehouse

    Edsall, Thomas A.; Brown, Charles L.; Kennedy, Gregory W.; Poe, Thomas P.

    1992-01-01

    Attempts to reestablish self-sustaining stocks of lake trout (Salvelinus namaycush) in the lower four Great Lakes, where the species was extinguished in the 1950s and 1960s, have been largely unsuccessful. To avoid many of the problems believed to be contributing to this failure, the fishery management community recently established several sanctuaries in the offshore waters of the Great Lakes where the development and protection of self-sustaining stocks of lake trout would be a primary management objective. One of these, the Six Fathom Bank-Yankee Reef sanctuary, was created in the south-central portion of Lake Huron. This sanctuary covers 168,000 ha and includes the shallower portions of the Six Fathom and Ipperwash scarps, which are major bathymetric features in the southern half of the lake. Historical accounts describe Six Fathom Bank as the most important lake trout spawning ground in the lake. Here we present the results of lake bed surveys conducted in the sanctuary with side-scan sonar, underwater videocamera systems, and a small research submarine. Our observations of the lake bed are consistent with what is known of the bedrock stratigraphy, glacial history, and karst geomorphology of the Lake Huron basin. Most of the loose rock we found seemed to be derived from local carbonate bedrock formations, although non-carbonate rock probably from Precambrian sources to the north was also present in some areas. Much of the bedrock and loose rock displayed karst solution features described for the Bruce Peninsula on the Ontario shoreline. Our surveys revealed substantial areas of lake bed at water depths of 20–36 m that resembled suitable spawning and fry production habitat for the shallow-water strains of lake trout that are the focus of the rehabilitation effort. Low mid-lake nutrient levels documented recently by others and the extremely high abundance of Mysis relicta (an important item in the diet of young lake trout) that we documented on Yankee Reef

  16. Lake-level variability and water availability in the Great Lakes

    USGS Publications Warehouse

    Wilcox, Douglas A.; Thompson, Todd A.; Booth, Robert K.; Nicholas, J.R.

    2007-01-01

    In this report, we present recorded and reconstructed (pre-historical) changes in water levels in the Great Lakes, relate them to climate changes of the past, and highlight major water-availability implications for storage, coastal ecosystems, and human activities. 'Water availability,' as conceptualized herein, includes a recognition that water must be available for human and natural uses, but the balancing of how much should be set aside for which use is not discussed. The Great Lakes Basin covers a large area of North America. The lakes capture and store great volumes of water that are critical in maintaining human activities and natural ecosystems. Water enters the lakes mostly in the form of precipitation and streamflow. Although flow through the connecting channels is a primary output from the lakes, evaporation is also a major output. Water levels in the lakes vary naturally on timescales that range from hours to millennia; storage of water in the lakes changes at the seasonal to millennial scales in response to lake-level changes. Short-term changes result from storm surges and seiches and do not affect storage. Seasonal changes are driven by differences in net basin supply during the year related to snowmelt, precipitation, and evaporation. Annual to millennial changes are driven by subtle to major climatic changes affecting both precipitation (and resulting streamflow) and evaporation. Rebounding of the Earth's surface in response to loss of the weight of melted glaciers has differentially affected water levels. Rebound rates have not been uniform across the basin, causing the hydrologic outlet of each lake to rise in elevation more rapidly than some parts of the coastlines. The result is a long-term change in lake level with respect to shoreline features that differs from site to site. The reconstructed water-level history of Lake Michigan-Huron over the past 4,700 years shows three major high phases from 2,300 to 3,300, 1,100 to 2,000, and 0 to 800

  17. Obesity framing for health policy development in Australia, France and Switzerland.

    PubMed

    Patchett, Annabelle D; Yeatman, Heather R; Johnson, Keryn M

    2016-03-01

    The obesity epidemic is a consequence of the interaction of cultural, environmental, genetic and behavioural factors; framing the issue is central to determining appropriate solutions. This study used content and thematic framing analysis to explore portrayal of responsibility for obesity in policy documents in Australia, France and Switzerland. For Australia and France, obesity causality was a combination of individual and environmental factors, but for Switzerland, it was predominantly individual. The primary solutions for all countries were health promotion strategies and children's education. Industry groups proposed more school education while health advocates advised government intervention. Where France emphasized cultural attitudes towards taste, Australia focused on sport. The French were most keen on legislating against unhealthy foods compared with Switzerland where there was opposition towards regulation of individual's choices. To curb the increasing prevalence of obesity, allocation of responsibility needs to be considered and initiatives enacted accordingly. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. Lake Life.

    ERIC Educational Resources Information Center

    Ohrn, Deborah Gore, Ed.

    1993-01-01

    This quarterly publication of the State Historical Society of Iowa features articles and activities for elementary school students. This summer issue focuses on the topic of lake life. The issue includes the following features: (1) "Where the Lakes Are Map"; (2) "Letter from the Lake"; (3) "Lake People"; (4)…

  19. Increased piscivory by lake whitefish in Lake Huron

    USGS Publications Warehouse

    Pothoven, Steven A.; Madenjian, Charles P.

    2013-01-01

    We evaluated the diet of Lake Whitefish Coregonus clupeaformis in Lake Huron during 2002–2011 to determine the importance of Round Goby Neogobius melanostomus and other fish as prey items. Lake Whitefish that had reached approximately 400 mm in length incorporated fish into their diets. The overall percentage of adult Lake Whitefish in Lake Huron that had eaten fish increased from 10% in 2002–2006 to 20% in 2007–2011, with a corresponding decrease in the frequency of Lake Whitefish that ate Dreissena spp. from 52% to 33%. During 2002–2006, Round Goby (wet mass, 38%), sculpins (Cottidae) (34%), and Ninespine Stickleback Pungitius pungitius (18%) were the primary fish eaten, whereas Round Goby accounted for 92% of the fish eaten in 2007–2011. Overall, Round Goby were found in the fewest Lake Whitefish stomachs in the north region of Lake Huron (6%) and in the most in the central (23%) and south (19%) regions of the lake. In the central region, Round Goby were eaten during all seasons that were sampled (spring through fall). In the south region, Round Goby were eaten only in the winter and spring but not in the summer when Dreissena spp. and spiny water flea Bythotrephes longimanus dominated the diet. Based on the 2007–2011 diet composition, an individual Lake Whitefish would need to have increased their consumption relative to that in 1983–1994 by 6% in the north region, 12% in the central region, and 41% in the southern region in order to achieve the same growth that was observed before dreissenid mussels arrived. However, Lake Whitefish weight adjusted for length only increased by 2% between 2002–2006 and 2007–2011 in the central region, decreased by 4% in the northern region, and remained constant in the southern region. This suggests that a shift toward more frequent piscivory does not necessarily improve the condition of a generalist feeder like Lake Whitefish.

  20. Regionalization of monthly rainfall erosivity patternsin Switzerland

    NASA Astrophysics Data System (ADS)

    Schmidt, Simon; Alewell, Christine; Panagos, Panos; Meusburger, Katrin

    2016-10-01

    One major controlling factor of water erosion is rainfall erosivity, which is quantified as the product of total storm energy and a maximum 30 min intensity (I30). Rainfall erosivity is often expressed as R-factor in soil erosion risk models like the Universal Soil Loss Equation (USLE) and its revised version (RUSLE). As rainfall erosivity is closely correlated with rainfall amount and intensity, the rainfall erosivity of Switzerland can be expected to have a regional characteristic and seasonal dynamic throughout the year. This intra-annual variability was mapped by a monthly modeling approach to assess simultaneously spatial and monthly patterns of rainfall erosivity. So far only national seasonal means and regional annual means exist for Switzerland. We used a network of 87 precipitation gauging stations with a 10 min temporal resolution to calculate long-term monthly mean R-factors. Stepwise generalized linear regression (GLM) and leave-one-out cross-validation (LOOCV) were used to select spatial covariates which explain the spatial and temporal patterns of the R-factor for each month across Switzerland. The monthly R-factor is mapped by summarizing the predicted R-factor of the regression equation and the corresponding residues of the regression, which are interpolated by ordinary kriging (regression-kriging). As spatial covariates, a variety of precipitation indicator data has been included such as snow depths, a combination product of hourly precipitation measurements and radar observations (CombiPrecip), daily Alpine precipitation (EURO4M-APGD), and monthly precipitation sums (RhiresM). Topographic parameters (elevation, slope) were also significant explanatory variables for single months. The comparison of the 12 monthly rainfall erosivity maps showed a distinct seasonality with the highest rainfall erosivity in summer (June, July, and August) influenced by intense rainfall events. Winter months have the lowest rainfall erosivity. A proportion

  1. Holocene lake-level fluctuations of Lake Aricota, Southern Peru

    USGS Publications Warehouse

    Placzek, C.; Quade, Jay; Betancourt, J.L.

    2001-01-01

    Lacustrine deposits exposed around Lake Aricota, Peru (17?? 22???S), a 7.5-km2 lake dammed by debris flows, provide a middle to late Holocene record of lake-level fluctuations. Chronological context for shoreline deposits was obtained from radiocarbon dating of vascular plant remains and other datable material with minimal 14C reservoir effects (<350 yr). Diatomites associated with highstands several meters above the modern lake level indicate wet episodes. Maximum Holocene lake level was attained before 6100 14C yr B.P. and ended ???2700 14C yr B.P. Moderately high lake levels occurred at 1700 and 1300 14C yr B.P. The highstand at Lake Aricota during the middle Holocene is coeval with a major lowstand at Lake Titicaca (16?? S), which is only 130 km to the northeast and shares a similar climatology. Comparisons with other marine and terrestrial records highlight emerging contradictions over the nature of mid-Holocene climate in the central Andes. ?? 2001 University of Washington.

  2. Holocene Lake-Level Fluctuations of Lake Aricota, Southern Peru

    NASA Astrophysics Data System (ADS)

    Placzek, Christa; Quade, Jay; Betancourt, Julio L.

    2001-09-01

    Lacustrine deposits exposed around Lake Aricota, Peru (17° 22‧S), a 7.5-km2 lake dammed by debris flows, provide a middle to late Holocene record of lake-level fluctuations. Chronological context for shoreline deposits was obtained from radiocarbon dating of vascular plant remains and other datable material with minimal 14C reservoir effects (<350 yr). Diatomites associated with highstands several meters above the modern lake level indicate wet episodes. Maximum Holocene lake level was attained before 6100 14C yr B.P. and ended ∼2700 14C yr B.P. Moderately high lake levels occurred at 1700 and 1300 14C yr B.P. The highstand at Lake Aricota during the middle Holocene is coeval with a major lowstand at Lake Titicaca (16°S), which is only 130 km to the northeast and shares a similar climatology. Comparisons with other marine and terrestrial records highlight emerging contradictions over the nature of mid-Holocene climate in the central Andes.

  3. Reevaluation of lake trout and lake whitefish bioenergetics models

    USGS Publications Warehouse

    Madenjian, Charles P.; Pothoven, Steve A.; Kao, Yu-Chun

    2013-01-01

    Using a corrected algorithm for balancing the energy budget, we reevaluated the Wisconsin bioenergetics model for lake trout (Salvelinus namaycush) in the laboratory and for lake whitefish (Coregonus clupeaformis) in the laboratory and in the field. For lake trout, results showed that the bioenergetics model slightly overestimated food consumption by the lake trout when they were fed low and intermediate rations, whereas the model predicted food consumption by lake trout fed ad libitum without any detectable bias. The slight bias in model predictions for lake trout on restricted rations may have been an artifact of the feeding schedule for these fish, and we would therefore recommend application of the Wisconsin lake trout bioenergetics model to lake trout populations in the field without any revisions to the model. Use of the Wisconsin bioenergetics model for coregonids resulted in overestimation of food consumption by lake whitefish both in the laboratory and in the field by between 20 and 30%, on average. This overestimation of food consumption was most likely due to overestimation of respiration rate. We therefore adjusted the respiration component of the bioenergetics model to obtain a good fit to the observed consumption in our laboratory tanks. The adjusted model predicted the consumption in the laboratory and the field without any detectable bias. Until a detailed lake whitefish respiration study can be conducted, we recommend application of our adjusted version of the Wisconsin generalized coregonid bioenergetics model to lake whitefish populations in the field.

  4. Late Holocene lake-level fluctuations in Walker Lake, Nevada, USA

    USGS Publications Warehouse

    Yuan, F.; Linsley, B.K.; Howe, S.S.; Lund, S.P.; McGeehin, J.P.

    2006-01-01

    Walker Lake, a hydrologically closed, saline, and alkaline lake, is situated along the western margin of the Great Basin in Nevada of the western United States. Analyses of the magnetic susceptibility (??), total inorganic carbon (TIC), and oxygen isotopic composition (??18O) of carbonate sediments including ostracode shells (Limnocythere ceriotuberosa) from Walker Lake allow us to extend the sediment record of lake-level fluctuations back to 2700??years B.P. There are approximately five major stages over the course of the late Holocene hydrologic evolution in Walker Lake: an early lowstand (> 2400??years B.P.), a lake-filling period (??? 2400 to ??? 1000??years B.P.), a lake-level lowering period during the Medieval Warm Period (MWP) (??? 1000 to ??? 600??years B.P.), a relatively wet period (??? 600 to ??? 100??years B.P.), and the anthropogenically induced lake-level lowering period (< 100??years B.P.). The most pronounced lowstand of Walker Lake occurred at ??? 2400??years B.P., as indicated by the relatively high values of ??18O. This is generally in agreement with the previous lower resolution paleoclimate results from Walker Lake, but contrasts with the sediment records from adjacent Pyramid Lake and Siesta Lake. The pronounced lowstand suggests that the Walker River that fills Walker Lake may have partially diverted into the Carson Sink through the Adrian paleochannel between 2700 to 1400??years B.P. ?? 2006 Elsevier B.V. All rights reserved.

  5. [Publication performances of university clinics for anesthesiology: Germany, Austria and Switzerland from 2001 to 2010].

    PubMed

    Putzer, G; Ausserer, J; Wenzel, V; Pehböck, D; Widmann, T; Lindner, K; Hamm, P; Paal, P

    2014-04-01

    This study assessed the publication performance of university departments of anesthesiology in Austria, Germany and Switzerland. The number of publications, original articles, impact factors and citations were evaluated. A search was performed in PubMed to identify publications related to anesthesiology from 2001 to 2010. All articles from anesthesiology journals listed in the fields of anesthesia/pain therapy, critical care and emergency medicine by the "journal citation report 2013" in Thomson Reuters ISI web of knowledge were included. Articles from non-anaesthesiology journals, where the stem of the word anesthesia (anes*, anaes*, anäst*, anast*) appears in the affiliation field of PubMed, were included as well. The time periods 2001-2005 and 2006-2010 were compared. Articles were allocated to university departments in Austria, Germany and Switzerland via the affiliation field. A total of 45 university departments in Austria, Germany and Switzerland and 125,979 publications from 2,863 journals (65 anesthesiology journals, 2,798 non-anesthesiology journals) were analyzed. Of the publications 23 % could not be allocated to a given university department of anesthesiology. In the observation period the university department of anesthesiology in Berlin achieved most publications (n = 479) and impact points (1,384), whereas Vienna accumulated most original articles (n = 156). Austria had the most publications per million inhabitants in 2006-2010 (n=50) followed by Switzerland (n=49) and Germany (n=35). The number of publications during the observation period decreased in Germany (0.5 %), Austria (7 %) and Switzerland (8 %). Tables 2 and 4-8 of this article are available at Springer Link under Supplemental. The research performance varied among the university departments of anesthesiology in Germany, Austria and Switzerland whereby larger university departments, such as Berlin or Vienna published most. Publication output in Germany, Austria and

  6. Bathythermal habitat use by strains of Great Lakes- and Finger Lakes-origin lake trout in Lake Huron after a change in prey fish abundance and composition

    USGS Publications Warehouse

    Bergstedt, Roger A.; Argyle, Ray L.; Krueger, Charles C.; Taylor, William W.

    2012-01-01

    A study conducted in Lake Huron during October 1998–June 2001 found that strains of Great Lakes-origin (GLO) lake trout Salvelinus namaycush occupied significantly higher temperatures than did Finger Lakes-origin (FLO; New York) lake trout based on data from archival (or data storage) telemetry tags that recorded only temperature. During 2002 and 2003, we implanted archival tags that recorded depth as well as temperature in GLO and FLO lake trout in Lake Huron. Data subsequently recorded by those tags spanned 2002–2005. Based on those data, we examined whether temperatures and depths occupied by GLO and FLO lake trout differed during 2002–2005. Temperatures occupied during those years were also compared with occupied temperatures reported for 1998–2001, before a substantial decline in prey fish biomass. Temperatures occupied by GLO lake trout were again significantly higher than those occupied by FLO lake trout. This result supports the conclusion of the previous study. The GLO lake trout also occupied significantly shallower depths than FLO lake trout. In 2002–2005, both GLO and FLO lake trout occupied significantly lower temperatures than they did in 1998–2001. Aside from the sharp decline in prey fish biomass between study periods, the formerly abundant pelagic alewife Alosa pseudoharengus virtually disappeared and the demersal round goby Neogobius melanostomus invaded the lake and became locally abundant. The lower temperatures occupied by lake trout in Lake Huron during 2002–2005 may be attributable to changes in the composition of the prey fish community, food scarcity (i.e., a retreat to cooler water could increase conversion efficiency), or both.

  7. Chemours Pompton Lakes Works Site, Pompton Lakes, NJ

    EPA Pesticide Factsheets

    E.I. DuPont De Nemours & Company is located at 2000 Cannonball Road, Pompton Lakes, New Jersey. The DuPont Pompton Lakes Works site (DuPont) occupies approximately 570 acres of land in Pompton Lakes and Wanaque.

  8. Providing Quality Therapeutics in Switzerland: Role of the Stakeholders and Recent Incentives for Further Improvements.

    PubMed

    Besson, Marie; Samer, Caroline; Rollason, Victoria; Dayer, Pierre; Desmeules, Jules

    2015-07-01

    Quality therapeutics play an important role in Switzerland's health care and economy. Switzerland holds a key position in the world of research and development, as well as in drug production. Recently, new emphasis has been placed on promoting clinical research and maintaining Switzerland's position as a center of excellence in the field. Recent revisions to the law regarding medical trials in human research allow for better allocation of regulatory resources and simplified procedures for drugs already authorized in Switzerland. The country has its own regulatory agency, the Swiss Agency for Therapeutic Products (Swissmedic), which is a public institution of the Swiss government. Swissmedic is responsible for ensuring safety in medicines, particularly regarding authorizations and market surveillance in the sector of medicinal products and medical devices. Although the centralized authorization procedure of the European Union for medicines does not apply to Switzerland, there are mutual recognition mechanisms between the Swiss medicine regulatory authority and the European Medicines Agency. Swissmedic is also in charge of postmarketing safety and oversees the national pharmacovigilance center, which collaborates closely with the World Health Organization center in Uppsala. In addition, university hospital-based clinical pharmacologists, who are involved in basic science and clinical research, regulatory affairs, ethics committees, and pharmacovigilance, promote quality therapeutics. This article discusses the role of the various stakeholders and the recent efforts made to provide a better allocation of resources aimed at further improving quality therapeutics in Switzerland. Copyright © 2015 Elsevier HS Journals, Inc. All rights reserved.

  9. Culture, risk factors and mortality: can Switzerland add missing pieces to the European puzzle?

    PubMed

    Faeh, D; Minder, C; Gutzwiller, F; Bopp, M

    2009-08-01

    The aim was to compare cause-specific mortality, self-rated health (SRH) and risk factors in the French and German part of Switzerland and to discuss to what extent variations between these regions reflect differences between France and Germany. Data were used from the general population of German and French Switzerland with 2.8 million individuals aged 45-74 years, contributing 176 782 deaths between 1990 and 2000. Adjusted mortality risks were calculated from the Swiss National Cohort, a longitudinal census-based record linkage study. Results were contrasted with cross-sectional analyses of SRH and risk factors (Swiss Health Survey 1992/3) and with cross-sectional national and international mortality rates for 1980, 1990 and 2000. Despite similar all-cause mortality, there were substantial differences in cause-specific mortality between Swiss regions. Deaths from circulatory disease were more common in German Switzerland, while causes related to alcohol consumption were more prevalent in French Switzerland. Many but not all of the mortality differences between the two regions could be explained by variations in risk factors. Similar patterns were found between Germany and France. Characteristic mortality and behavioural differentials between the German- and the French-speaking parts of Switzerland could also be found between Germany and France. However, some of the international variations in mortality were not in line with the Swiss regional comparison nor with differences in risk factors. These could relate to peculiarities in assignment of cause of death. With its cultural diversity, Switzerland offers the opportunity to examine cultural determinants of mortality without bias due to different statistical systems or national health policies.

  10. Porewater salinity reveals past lake-level changes in Lake Van, the Earth's largest soda lake.

    PubMed

    Tomonaga, Yama; Brennwald, Matthias S; Livingstone, David M; Kwiecien, Olga; Randlett, Marie-Ève; Stockhecke, Mona; Unwin, Katie; Anselmetti, Flavio S; Beer, Jürg; Haug, Gerald H; Schubert, Carsten J; Sturm, Mike; Kipfer, Rolf

    2017-03-22

    In closed-basin lakes, sediment porewater salinity can potentially be used as a conservative tracer to reconstruct past fluctuations in lake level. However, until now, porewater salinity profiles did not allow quantitative estimates of past lake-level changes because, in contrast to the oceans, significant salinity changes (e.g., local concentration minima and maxima) had never been observed in lacustrine sediments. Here we show that the salinity measured in the sediment pore water of Lake Van (Turkey) allows straightforward reconstruction of two major transgressions and a major regression that occurred during the last 250 ka. We observed strong changes in the vertical salinity profiles of the pore water of the uppermost 100 m of the sediments in Lake Van. As the salinity balance of Lake Van is almost at steady-state, these salinity changes indicate major lake-level changes in the past. In line with previous studies on lake terraces and with seismic and sedimentological surveys, we identify two major transgressions of up to +105 m with respect to the current lake level at about 135 ka BP and 248 ka BP starting at the onset of the two previous interglacials (MIS5e and MIS7), and a major regression of about -200 m at about 30 ka BP during the last ice age.

  11. Tinnitus functional index: validation of the German version for Switzerland.

    PubMed

    Peter, Nicole; Kleinjung, Tobias; Jeker, Raphael; Meyer, Martin; Klaghofer, Richard; Weidt, Steffi

    2017-05-05

    Different standardized questionnaires are used to assess tinnitus severity, making comparisons across studies difficult. These questionnaires are also used to measure treatment-related changes in tinnitus although they were not designed for this purpose. To solve these problems, a new questionnaire - the Tinnitus Functional Index (TFI) - has been established. The TFI is highly responsive to treatment-related change and promises to be the new gold standard in tinnitus evaluation. The aim of the current study was to validate a German version of the TFI for a German-speaking population in Switzerland. At the ENT department of the University Hospital Zurich, 264 subjects completed an online survey including the German version for Switzerland of TFI, Tinnitus Handicap Inventory (THI), Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI) and sociodemographic variables. Internal consistency of the TFI was calculated with Cronbach's alpha coefficient. Pearson correlation coefficients were used for the test-retest reliability of the TFI and to investigate convergent and discriminant validity between the THI and the BDI and BAI, respectively. Factor analysis was assessed using a principal component analysis with oblique rotation. The different factors extracted were then compared with the original questionnaire. The German version of the TFI for Switzerland showed an excellent internal consistency (Cronbach's alpha of 0.97) and an excellent test-retest reliability of 0.91. The convergent validity with THI was high (r = 0.86). The discriminant validity with BAI and BDI showed moderate results (BAI: r = 0.60 and BDI: r = 0.65). In the factor analysis only five factors with one main factor could be extracted instead of eight factors as described in the original version. Nevertheless, relations to the original eight subscales could be demonstrated. The German version of the TFI for Switzerland is a suitable instrument for measuring the impact of tinnitus

  12. Spatial and temporal genetic diversity of lake whitefish (Coregonus clupeaformis (Mitchill)) from Lake Huron and Lake Erie

    USGS Publications Warehouse

    Stott, Wendylee; Ebener, Mark P.; Mohr, Lloyd; Hartman, Travis; Johnson, Jim; Roseman, Edward F.

    2013-01-01

    Lake whitefish (Coregonus clupeaformis (Mitchill)) are important commercially, culturally, and ecologically in the Laurentian Great Lakes. Stocks of lake whitefish in the Great Lakes have recovered from low levels of abundance in the 1960s. Reductions in abundance, loss of habitat and environmental degradation can be accompanied by losses of genetic diversity and overall fitness that may persist even as populations recover demographically. Therefore, it is important to be able to identify stocks that have reduced levels of genetic diversity. In this study, we investigated patterns of genetic diversity at microsatellite DNA loci in lake whitefish collected between 1927 and 1929 (historical period) and between 1997 and 2005 (contemporary period) from Lake Huron and Lake Erie. Genetic analysis of lake whitefish from Lakes Huron and Erie shows that the amount of population structuring varies from lake to lake. Greater genetic divergences among collections from Lake Huron may be the result of sampling scale, migration patterns and demographic processes. Fluctuations in abundance of lake whitefish populations may have resulted in periods of increased genetic drift that have resulted in changes in allele frequencies over time, but periodic genetic drift was not severe enough to result in a significant loss of genetic diversity. Migration among stocks may have decreased levels of genetic differentiation while not completely obscuring stock boundaries. Recent changes in spatial boundaries to stocks, the number of stocks and life history characteristics of stocks further demonstrate the potential of coregonids for a swift and varied response to environmental change and emphasise the importance of incorporating both spatial and temporal considerations into management plans to ensure that diversity is preserved.

  13. Dietary proteins in humans: basic aspects and consumption in Switzerland.

    PubMed

    Guigoz, Yves

    2011-03-01

    This introductory review gives an overview on protein metabolism, and discusses protein quality, sources, and requirements as well as the results from recent studies on Swiss spontaneous protein consumption. To assess protein quality in protein mixes and foods, the "protein digestibility-corrected amino acid score" (PDCAAS) is presented as a valuable tool in addition to the biological value (BV). Considering protein intake recommendations, the lower limit recommended has been defined according to the minimal amount needed to maintain short-term nitrogen balance in healthy people with moderate activity. Evaluation of intakes in Switzerland from food consumption data is about 90 g/day of protein per person. Two-thirds of proteins consumed in Switzerland are animal proteins with high biological value [meat and meat products (28 %), milk and dairy products (28 %), fish (3 %), and eggs (3 %)] and about 1/3 of proteins are of plant origin (25 % of cereals, 3 - 4 % of vegetables). Actual spontaneous protein consumption in Switzerland by specific groups of subjects is well within the actual recommendations (10 - 20 % of energy) with only the frail elderly being at risk of not covering their requirements for protein.

  14. Results of international Dobson spectrophotometer calibrations at Arosa, Switzerland, 1990

    NASA Technical Reports Server (NTRS)

    Grass, R. D.; Komhyr, W. D.; Koenig, G. L.; Evans, R. D.

    1994-01-01

    An international comparison of Dobson ozone spectrophotometers, organized and partially funded by the World Meteorological Organization (WMO), was held at the Lichtklimatisches Observatorium (LKO) in Arosa, Switzerland, July-August 1990. Countries participating with a total of 18 Dobson instruments were Belgium, Czechoslovakia, Denmark, Germany, Greece, Hungary, Iceland, Norway, Poland, Portugal, Rumania, Spain, Switzerland, the United Kingdom, the United States, and the United Soviet Socialist Republics. The reference standard instrument for the comparison was U.S.A. Secondary Standard Dobson Spectrophotometer 65 maintained by the NOAA Climate and Monitoring and Diagnostics Laboratory, Boulder, Colorado. The mean difference in ozone obtained with the Dobson instruments relative to Dobson instrument 65, calculated from ADDSGQP observations in the air mass range 1.15-3.2, was minus 1.0 plus or minus 1.2 (1 sigma) percent. The WMO Standard Brewer Spectrometer 39 also participated. In the mean, the Brewer instrument measured 0.6 plus or minus 0.2 (1 sigma) percent more ozone than did Dobson instrument 65. Results are presented, also, of ozone vertical profile measurements made with the Dobson instruments, two Brewer spectrometers, a LIDAR, a balloon ozonesonde flown from Hohenpeissenberg, Germany, and balloon ozonesondes flown from Payerne, Switzerland.

  15. Opioid maintenance therapy in Switzerland: an overview of the Swiss IMPROVE study.

    PubMed

    Besson, J; Beck, T; Wiesbeck, G; Hämmig, R; Kuntz, A; Abid, S; Stohler, R

    2014-01-01

    Switzerland's drug policy model has always been unique and progressive, but there is a need to reassess this system in a rapidly changing world. The IMPROVE study was conducted to gain understanding of the attitudes and beliefs towards opioid maintenance therapy (OMT) in Switzerland with regards to quality and access to treatment. To obtain a "real-world" view on OMT, the study approached its goals from two different angles: from the perspectives of the OMT patients and of the physicians who treat patients with maintenance therapy. The IMPROVE study collected a large body of data on OMT in Switzerland. This paper presents a small subset of the dataset, focusing on the research design and methodology, the profile of the participants and the responses to several key questions addressed by the questionnaires. IMPROVE was an observational, questionnaire-based cross-sectional study on OMT conducted in Switzerland. Respondents consisted of OMT patients and treating physicians from various regions of the country. Data were collected using questionnaires in German and French. Physicians were interviewed by phone with a computer-based questionnaire. Patients self-completed a paper-based questionnaire at the physicians' offices or OMT treatment centres. A total of 200 physicians and 207 patients participated in the study. Liquid methadone and methadone tablets or capsules were the medications most commonly prescribed by physicians (60% and 20% of patient load, respectively) whereas buprenorphine use was less frequent. Patients (88%) and physicians (83%) were generally satisfied with the OMT currently offered. The current political framework and lack of training or information were cited as determining factors that deter physicians from engaging in OMT. About 31% of OMT physicians interviewed were ≥60 years old, indicating an ageing population. Diversion and misuse were considered a significant problem in Switzerland by 45% of the physicians. The subset of IMPROVE data

  16. Movements of hatchery-reared lake trout in Lake Superior

    USGS Publications Warehouse

    Pycha, Richard L.; Dryer, William R.; King, George R.

    1965-01-01

    The history of stocking of lake trout (Salvelinus namaycush) in the Great Lakes is reviewed. The study of movements is based on capture of 24,275 fin-clipped lake trout taken in experimental gill nets and trawls and commercial gill nets. Yearling lake trout planted from shore dispersed to 15-fath (27-m) depths in 3A? hr. Most fish remained within 2 miles (3.2 km) of the planting site 2 months, but within 4 months some fish had moved as much as 17 miles (27 km). The highest abundance of planted lake trout was in areas 2-4 miles (3.2-6.4 km) from the planting site even 3 years after release. Distance moved and size of fish were not correlated. Dispersal of lake trout begins at planting and probably continues until the fish are mature. Most movement was eastward in southern Lake Superior and followed the counterclockwise surface currents. Movement is most rapid in areas of strong currents and slowest in areas of weak currents or eddies. Movement to areas west of the Keweenaw Peninsula was insignificant from plantings in Keweenaw Bay and nil from other plantings farther east. Lake trout planted in the eastern third of the lake dispersed more randomly than those planted farther west. Few fish moved farther offshore than the 50-fath (91-m) contour. Lake trout planted in Canadian waters made insignificant contributions to populations in US waters.

  17. Educational inequalities in mortality and associated risk factors: German--versus French-speaking Switzerland.

    PubMed

    Faeh, David; Bopp, Matthias

    2010-09-22

    Between the French- and German-speaking areas of Switzerland, there are distinct differences in mortality, similar to those between Germany and France. Assessing corresponding inequalities may elucidate variations in mortality and risk factors, thereby uncovering public health potential. Our aim was to analyze educational inequalities in all-cause and cause-specific mortality in the two Swiss regions and to compare this with inequalities in behavioural risk factors and self-rated health. The Swiss National Cohort, a longitudinal census-based record linkage study, provided mortality and survival time data (3.5 million individuals, 40-79 years, 261,314 deaths, 1990-2000). The Swiss Health Survey 1992/93 provided cross-sectional data on risk factors. Inequalities were calculated as percentage of change in mortality rate (survival time, hazard ratio) or risk factor prevalence (odds ratio) per year of additional education using multivariable Cox and logistic regression. Significant inequalities in mortality were found for all causes of death in men and for most causes in women. Inequalities were largest in men for causes related to smoking and alcohol use and in women for circulatory diseases. Gradients in all-cause mortality were more pronounced in younger and middle-aged men, especially in German-speaking Switzerland. Mortality inequalities tended to be larger in German-speaking Switzerland whereas inequalities in associated risk factors were generally more pronounced in French-speaking Switzerland. With respect to inequalities in mortality and associated risk factors, we found characteristic differences between German- and French-speaking Switzerland, some of which followed gradients described in Europe. These differences only partially reflected inequalities in associated risk factors.

  18. Molecular epidemiology of hepatitis B virus infection in Switzerland: a retrospective cohort study.

    PubMed

    Hirzel, Cédric; Wandeler, Gilles; Owczarek, Marta; Gorgievski-Hrisoho, Meri; Dufour, Jean-Francois; Semmo, Nasser; Zürcher, Samuel

    2015-10-30

    Chronic hepatitis B virus (HBV) infection affects up to 7% of the European population. Specific HBV genotypes are associated with rapid progression to end-stage liver disease and sub-optimal interferon treatment responses. Although the geographic distribution of HBV genotypes differs between regions, it has not been studied in Switzerland, which lies at the crossroads of Europe. In a retrospective analysis of 465 HBV samples collected between 2002 and 2013, we evaluated the HBV genotype distribution and phylogenetic determinants, as well as the prevalence of serological evidence of hepatitis delta, hepatitis C and HIV infections in Switzerland. Baseline characteristics of patients were compared across their region of origin using Fisher's exact test and ANOVA, and risk factors for HBeAg positivity were assessed using logistic regression. The Swiss native population represented 15.7% of HBV-infected patients living in Switzerland. In the overall population, genotype D was most prevalent (58.3%), whereas genotype A (58.9%) was the predominant genotype among the Swiss native population. The prevalence of patients with anti-HDV antibodies was 4.4%. Patients of Swiss origin were most likely to be HBeAg-positive (38.1%). HBV genotypes of patients living in Switzerland but sharing the same original region of origin were consistent with their place of birth. The molecular epidemiology of HBV infection in Switzerland is driven by migration patterns and not by the genotype distribution of the native population. The prevalence of positive anti-HDV antibodies in our cohort was very low.

  19. Energy density of lake whitefish Coregonus clupeaformis in Lakes Huron and Michigan

    USGS Publications Warehouse

    Pothoven, S.A.; Nalepa, T.F.; Madenjian, C.P.; Rediske, R.R.; Schneeberger, P.J.; He, J.X.

    2006-01-01

    We collected lake whitefish Coregonus clupeaformis off Alpena and Tawas City, Michigan, USA in Lake Huron and off Muskegon, Michigan USA in Lake Michigan during 2002–2004. We determined energy density and percent dry weight for lake whitefish from both lakes and lipid content for Lake Michigan fish. Energy density increased with increasing fish weight up to 800 g, and then remained relatively constant with further increases in fish weight. Energy density, adjusted for weight, was lower in Lake Huron than in Lake Michigan for both small (≤800 g) and large fish (>800 g). Energy density did not differ seasonally for small or large lake whitefish or between adult male and female fish. Energy density was strongly correlated with percent dry weight and percent lipid content. Based on data from commercially caught lake whitefish, body condition was lower in Lake Huron than Lake Michigan during 1981–2003, indicating that the dissimilarity in body condition between the lakes could be long standing. Energy density and lipid content in 2002–2004 in Lake Michigan were lower than data for comparable sized fish collected in 1969–1971. Differences in energy density between lakes were attributed to variation in diet and prey energy content as well as factors that affect feeding rates such as lake whitefish density and prey abundance.

  20. Effects of lake trout refuges on lake whitefish and cisco in the Apostle Islands Region of Lake Superior

    USGS Publications Warehouse

    Zuccarino-Crowe , Chiara M.; Taylor, William W.; Hansen, Michael J.; Seider, Michael J.; Krueger, Charles C.

    2016-01-01

    Lake trout refuges in the Apostle Islands region of Lake Superior are analogous to the concept of marine protected areas. These refuges, established specifically for lake trout (Salvelinus namaycush) and closed to most forms of recreational and commercial fishing, were implicated as one of several management actions leading to successful rehabilitation of Lake Superior lake trout. To investigate the potential significance of Gull Island Shoal and Devils Island Shoal refuges for populations of not only lake trout but also other fish species, relative abundances of lake trout, lake whitefish (Coregonus clupeaformis), and cisco (Coregonus artedi) were compared between areas sampled inside versus outside of refuge boundaries. During 1982–2010, lake trout relative abundance was higher and increased faster inside the refuges, where lake trout fishing was prohibited, than outside the refuges. Over the same period, lake whitefish relative abundance increased faster inside than outside the refuges. Both evaluations provided clear evidence that refuges protected these species. In contrast, trends in relative abundance of cisco, a prey item of lake trout, did not differ significantly between areas inside and outside the refuges. This result did not suggest indirect or cascading refuge effects due to changes in predator levels. Overall, this study highlights the potential of species-specific refuges to benefit other fish species beyond those that were the refuges' original target. Improved understanding of refuge effects on multiple species of Great Lakes fishes can be valuable for developing rationales for refuge establishment and predicting associated fish community-level effects.

  1. DSM Generation from ALSO/PRISM Images Using SAT-PP

    NASA Astrophysics Data System (ADS)

    Wolff, Kirsten; Gruen, Armin

    2008-11-01

    One of the most important products of ALOS/PRISM image data are accurate DSMs. To exploit the full potential of the full resolution of PRISM for DSM generation, a highly developed image matcher is needed. As a member of the validation and calibration team for PRISM we published earlier results of DSM generation using PRISM image triplets in combination with our software package SAT-PP. The overall accuracy across all object and image features for all tests lies between 1-5 pixels in matching, depending primarily on surface roughness, vegetation, image texture and image quality. Here we will discuss some new results. We focus on four different topics: the use of two different evaluation methods, the difference between a 5m and a 10m GSD for the final PRISM DSM, the influence of the level of initial information and the comparison of the quality of different combinations of the three different views forward, nadir and backward. All tests have been conducted with our testfield Bern/Thun, Switzerland.

  2. Future volcanic lake research: revealing secrets from poorly studied lakes

    NASA Astrophysics Data System (ADS)

    Rouwet, D.; Tassi, F.; Mora-Amador, R. A.

    2012-04-01

    Volcanic lake research boosted after the 1986 Lake Nyos lethal gas burst, a limnic rather than volcanic event. This led to the formation of the IAVCEI-Commission on Volcanic Lakes, which grew out into a multi-disciplinary scientific community since the 1990's. At Lake Nyos, a degassing pipe is functional since 2001, and two additional pipes were added in 2011, aimed to prevent further limnic eruption events. There are between 150 and 200 volcanic lakes on Earth. Some acidic crater lakes topping active magmatic-hydrothermal systems are monitored continuously or discontinuously. Such detailed studies have shown their usefulness in volcanic surveillance (e.g. Ruapehu, Yugama-Kusatsu-Shiran, Poás). Others are "Nyos-type" lakes, with possible gas accumulation in bottom waters and thus potentially hazardous. "Nyos-type" lakes tend to remain stably stratified in tropical and sub-tropical climates (meromictic), leading to long-term gas build-up and thus higher potential risk. In temperate climates, such lakes tend to turn over in winter (monomictic), and thus liberating its gas charge yearly. We line out research strategies for the different types of lakes. We believe a complementary, multi-disciplinary approach (geochemistry, geophysics, limnology, biology, statistics, etc.) will lead to new insights and ideas, which can be the base for future following-up and monitoring. After 25 years of pioneering studies on rather few lakes, the scientific community should be challenged to study the many poorly studied volcanic lakes, in order to better constrain the related hazard, based on probabilistic approaches.

  3. Gas exchange on Mono Lake and Crowley Lake, California

    NASA Technical Reports Server (NTRS)

    Wanninkhof, Rik; Ledwell, James R.; Broecker, Wallace S.

    1987-01-01

    Gas exchange coefficients (k) have been determined for freshwater Crowley Lake and saline Mono Lake through the use of a man-made purposefully injected gas, SF6. The concentration decreased from an initial value of 40 to 4 pmol/L for Mono Lake and from 20 to 1 pmol/L for Crowley lake over a period of 6 wks. Wind-speed (u) records from anemometers on the shore of each lake made it possible to determine the relationship between k and u. The average u and k values for the experiment were identical for the two lakes, despite the large chemical differences. It is estimated that, for the u values observed over Mono Lake from July to December 1984, the exchange of CO2 occurred 2.5 times faster than without chemical enhancement. This is a factor of 4 lower than needed to explain the high invasion rate of C-14 produced by nuclear bomb tests.

  4. Lake

    ERIC Educational Resources Information Center

    Wien, Carol Anne

    2008-01-01

    The lake is blue black and deep. It is a glaciated finger lake, clawed out of rock when ice retracted across Nova Scotia in a northerly direction during the last ice age. The lake is narrow, a little over a mile long, and deep, 90 to 190 feet in places according to local lore, off the charts in others. The author loves to swim there, with a sense…

  5. [Treatment Methods for Patients with Dupuytren's Disease in Switzerland].

    PubMed

    Marks, M; Krefter, C; Herren, D B

    2016-06-01

    The objective of this study was to investigate what treatment options are currently used in Switzerland for Dupuytren's disease. Furthermore, regional preferences and treatment differences based on surgeon experience were analysed. In this survey, an electronic questionnaire was sent to all members of the Swiss Society for Hand Surgery. Participants were asked to indicate their current treatment methods for Dupuytren's disease. In addition, 8 standard patient cases were presented to identify the preferred treatment option. Furthermore, sociodemographic data of the participants were gathered. In total, 70 questionnaires were completed, corresponding to a response rate of 34%. Fasciectomy is performed by 94% of participants, while 59% inject collagenase in certain cases, 40% perform open fasciotomy, and 24% carry out percutaneous needle aponeurotomy if the indication is given. 20% of responders offer one of these techniques, 50% offer 2, 23% offer 3, and 7% offer all 4 treatment techniques. In the case of isolated metacarpophalangeal joint contracture, 51% of participants inject collagenase, whereas fasciectomy is preferred for the treatment of proximal interphalangeal joint contractures or in cases of recurrence. In German-speaking Switzerland, the treatment strategy has changed towards applying collagenase injections in the past 5 years. In this part of the country, 83% of surgeons now use more collagenase than 5 years ago, whereas only 33% of surgeons in French-speaking Switzerland have changed their treatment strategy in favour of collagenase injections (p=0.027). Surgeons with less than 10 years of experience apply more collagenase than their more experienced colleagues (79 vs. 54%, p=0.131). In Switzerland, fasciectomy is the preferred option for treating patients with Dupuytren's disease. In recent years, however, collagenase injection has become more and more popular. More research is needed to define guidelines for the treatment of patients with Dupuytren

  6. Implementation of early intensive behavioural intervention for children with autism in Switzerland.

    PubMed

    Studer, Nadja; Gundelfinger, Ronnie; Schenker, Tanja; Steinhausen, Hans-Christoph

    2017-01-21

    There is a major gap between the US and most European countries regarding the implementation of early intensive behavioural intervention (EIBI) for children with autism. The present paper reports on the current status of EIBI in Switzerland and on the effectiveness of EIBI under clinical conditions in a Swiss pilot project. The paper combines a narrative report of the care system for children with autism in Switzerland and an initial evaluation of EIBI as implemented in the Department of Child and Adolescent Psychiatry, University of Zurich. The current situation of the implementation of EIBI for children with autism in Switzerland is characterized by marked deficits in its acceptance. Major reasons include insufficient governmental approval and lacking legal and financial support. In addition, ignorance among health care providers and educational professionals has contributed to this situation precluding that children with autism receive the most beneficial assistance. The authors have initiated and been working in an intervention centre offering EIBI for a decade and report on their experience with the implementation of EIBI. Based on their clinical practice, they document that EIBI also works efficiently under ordinary mental health service conditions. EIBI needs to be implemented more intensively in Switzerland. Although the effects of EIBI as implemented in Zurich are promising, the results are not as pronounced as under controlled research conditions.

  7. Reconnaissance data on lakes in the Alpine Lakes Wilderness Area, Washington

    USGS Publications Warehouse

    Dethier, David P.; Heller, Paul L.; Safioles, Sally A.

    1979-01-01

    Sixty lakes in the Alpine Lakes Wilderness Area have been sampled from rubber rafts or helicopter to obtain information on their physical setting and on present water-quality conditions. The lakes are located near the crest of the Cascade Range in Chelan and King Counties, Washington. Basic data from these lakes will be useful for planners concerned with lake and wilderness management, and of interest to hikers and other recreationists who use the lakes.

  8. 75 FR 20920 - Safety Zone; Lake Havasu Grand Prix, Lake Havasu, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-22

    ...-AA00 Safety Zone; Lake Havasu Grand Prix, Lake Havasu, AZ AGENCY: Coast Guard, DHS. ACTION: Temporary... of Lake Havasu on the Colorado River in Lake Havasu City, Arizona for the Lake Havasu Grand Prix... established in support of the Lake Havasu Grand Prix, a marine event that includes participating vessels...

  9. Water-Balance Model to Simulate Historical Lake Levels for Lake Merced, California

    NASA Astrophysics Data System (ADS)

    Maley, M. P.; Onsoy, S.; Debroux, J.; Eagon, B.

    2009-12-01

    Lake Merced is a freshwater lake located in southwestern San Francisco, California. In the late 1980s and early 1990s, an extended, severe drought impacted the area that resulted in significant declines in Lake Merced lake levels that raised concerns about the long-term health of the lake. In response to these concerns, the Lake Merced Water Level Restoration Project was developed to evaluate an engineered solution to increase and maintain Lake Merced lake levels. The Lake Merced Lake-Level Model was developed to support the conceptual engineering design to restore lake levels. It is a spreadsheet-based water-balance model that performs monthly water-balance calculations based on the hydrological conceptual model. The model independently calculates each water-balance component based on available climate and hydrological data. The model objective was to develop a practical, rule-based approach for the water balance and to calibrate the model results to measured lake levels. The advantage of a rule-based approach is that once the rules are defined, they enhance the ability to then adapt the model for use in future-case simulations. The model was calibrated to historical lake levels over a 70-year period from 1939 to 2009. Calibrating the model over this long historical range tested the model over a variety of hydrological conditions including wet, normal and dry precipitation years, flood events, and periods of high and low lake levels. The historical lake level range was over 16 feet. The model calibration of historical to simulated lake levels had a residual mean of 0.02 feet and an absolute residual mean of 0.42 feet. More importantly, the model demonstrated the ability to simulate both long-term and short-term trends with a strong correlation of the magnitude for both annual and seasonal fluctuations in lake levels. The calibration results demonstrate an improved conceptual understanding of the key hydrological factors that control lake levels, reduce uncertainty

  10. Flood damage claims reveal insights about surface runoff in Switzerland

    NASA Astrophysics Data System (ADS)

    Bernet, D. B.; Prasuhn, V.; Weingartner, R.

    2015-12-01

    A few case studies in Switzerland exemplify that not only overtopping water bodies frequently cause damages to buildings. Reportedly, a large share of the total loss due to flooding in Switzerland goes back to surface runoff that is formed and is propagating outside of regular watercourses. Nevertheless, little is known about when, where and why such surface runoff occurs. The described process encompasses surface runoff formation, followed by unchannelised overland flow until a water body is reached. It is understood as a type of flash flood, has short response times and occurs diffusely in the landscape. Thus, the process is difficult to observe and study directly. A promising source indicating surface runoff indirectly are houseowners' damage claims recorded by Swiss Public Insurance Companies for Buildings (PICB). In most of Switzerland, PICB hold a monopoly position and insure (almost) every building. Consequently, PICB generally register all damages to buildings caused by an insured natural hazard (including surface runoff) within the respective zones. We have gathered gapless flood related claim records of most of all Swiss PICB covering more than the last two decades on average. Based on a subset, we have developed a methodology to differentiate claims related to surface runoff from other causes. This allows us to assess the number of claims as well as total loss related to surface runoff and compare these to the numbers of overtopping watercourses. Furthermore, with the good data coverage, we are able to analyze surface runoff related claims in space and time, from which we can infer spatial and temporal characteristics of surface runoff. Although the delivered data of PICB are heterogeneous and, consequently, time-consuming to harmonize, our first results show that exploiting these damage claim records is feasible and worthwhile to learn more about surface runoff in Switzerland.

  11. White Lake AOC

    EPA Pesticide Factsheets

    White Lake is in Muskegon County along the eastern shore of Lake Michigan. It was named an Area of Concern on the Great Lakes under the Great Lakes Water Quality Agreement of 1987 and delisted in 2014.

  12. Cost distribution of bluetongue surveillance and vaccination programmes in Austria and Switzerland (2007-2016).

    PubMed

    Pinior, Beate; Firth, Clair L; Loitsch, Angelika; Stockreiter, Simon; Hutter, Sabine; Richter, Veronika; Lebl, Karin; Schwermer, Heinzpeter; Käsbohrer, Annemarie

    2018-03-03

    Bluetongue virus (BTV) is an emerging transboundary disease in Europe, which can cause significant production losses among ruminants. The analysis presented here assessed the costs of BTV surveillance and vaccination programmes in Austria and Switzerland between 2007 and 2016. Costs were compared with respect to time, type of programme, geographical area and who was responsible for payment. The total costs of the BTV vaccination and surveillance programmes in Austria amounted to €23.6 million, whereas total costs in Switzerland were €18.3 million. Our analysis demonstrates that the costs differed between years and geographical areas, both within and between the two countries. Average surveillance costs per animal amounted to approximately €3.20 in Austria compared with €1.30 in Switzerland, whereas the average vaccination costs per animal were €6.20 in Austria and €7.40 in Switzerland. The comparability of the surveillance costs is somewhat limited, however, due to differences in each nation's surveillance (and sampling) strategy. Given the importance of the export market for cattle production, investments in such programmes are more justified for Austria than for Switzerland. The aim of the retrospective assessment presented here is to assist veterinary authorities in planning and implementing cost-effective and efficient control strategies for emerging livestock diseases. © British Veterinary Association (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  13. Patient safety issues in office-based surgery and anaesthesia in Switzerland: a qualitative study.

    PubMed

    McLennan, Stuart; Schwappach, David; Harder, Yves; Staender, Sven; Elger, Bernice

    2017-08-01

    To identify the spectrum of patient safety issues in office-based surgery and anaesthesia in Switzerland. Purposive sample of 23 experts in surgery and anaesthesia and quality and regulation in Switzerland. Data were collected via individual qualitative interviews using a researcher-developed semi-structured interview guide between March 2016 and September 2016. Interviews were transcribed and analysed using conventional content analysis. Issues were categorised under the headings "structure", "process", and "outcome". Experts identified two key overarching patient safety and regulatory issues in relation to office-based surgery and anaesthesia in Switzerland. First, experts repeatedly raised the current lack of data and transparency of the setting. It is unknown how many surgeons are operating in offices, how many and what types of operations are being done, and what the outcomes are. Secondly, experts also noted the limited oversight and regulation of the setting. While some standards exists, most experts felt that more minimal safety standards are needed regarding the requirements that must be met to do office-based surgery and what can and cannot be done in the office-based setting are needed, but they advocated a self-regulatory approach. There is a lack of empirical data regarding the quantity and quality office-based surgery and anaesthesia in Switzerland. Further research is needed to address these research gaps and inform health policy in relation to patient safety in office-based surgery and anaesthesia in Switzerland. Copyright © 2017. Published by Elsevier GmbH.

  14. The region makes the difference: disparities in management of acute myocardial infarction within Switzerland.

    PubMed

    Insam, Charlène; Paccaud, Fred; Marques-Vidal, Pedro

    2014-05-01

    In Switzerland, health policies are decided at the local level, but little is known regarding their impact on the management of acute myocardial infarction (AMI). In this study, we assessed geographical differences within Switzerland regarding management of AMI. Cross-sectional study. Swiss hospital discharge database for period 2007-2008 (26,204 discharges from AMI). Seven Swiss regions (Leman, Mittelland, Northwest, Zurich, Central, Eastern, and Ticino) were analysed. Almost 53.7% of discharges from AMI were managed in a single hospital, ranging from 62.1% (Leman) to 31.6% (Ticino). The highest intensive care unit admission rate was in Leman (69.4%), the lowest (16.9%) in Ticino (Swiss average: 36.0%). Intracoronary revascularization rates were highest in Leman (51.1%) and lowest (30.9%) in Central Switzerland (average: 41.0%). Bare (non-drug-eluting) stent use was highest in Leman (61.4%) and lowest (16.9%) in Ticino (average: 42.1%), while drug-eluting stent use was highest (83.2%) in Ticino and lowest (38.6%) in Leman (average: 57.9%). Coronary artery bypass graft rates were highest (4.8%) in Ticino and lowest (0.5%) in Eastern Switzerland (average: 2.8%). Mechanical circulatory assistance rates were highest (4.2%) in Zurich and lowest (0.5%) in Ticino (average: 1.8%). The differences remained after adjusting for age, single or multiple hospital management, and gender. In Switzerland, significant geographical differences in management and revascularization procedures for AMI were found.

  15. [Reasons for General Practitioner Shortage – a Comparison Between France and Switzerland].

    PubMed

    Cerny, Thomas; Rosemann, Thomas; Tandjung, Ryan; Chmiel, Corinne

    2016-05-25

    Both France and Switzerland face a general practitioner (GP) shortage. What differences or parallels exist between the two countries with regard to the causes for this shortage? What conclusions might be drawn from a systematic comparison? Literature review with qualitative and semi-quantitative content analysis. Parallels exist in the comparing categories work contents, working structure, income and social status, medical school formation, private life, psychological motives. Differences are found in the categories biography and social selection, medical socialisation, residency. In Switzerland, residency is not uniformly structured, rarely institutionally organised and contains only few elements specific to general medicine. In France, medical socialisation not only exalts the specialists, but also strongly devaluates the GPs. By systematic analysis and comparison of both countries' pertinent literature, France and Switzerland can deepen their understanding of GP shortage. This paper identifies possible fields of action from medical school through residency up to workplace conditions that are pivotal in addressing the shortage of GPs.

  16. [How patient safety programmes can be successfully implemented - an example from Switzerland].

    PubMed

    Kobler, Irene; Mascherek, Anna; Bezzola, Paula

    2015-01-01

    Internationally, the implementation of patient safety programmes poses a major challenge. In the first part, we will demonstrate that various measures have been found to be effective in the literature but that they often do not reach the patient because their implementation proves difficult. Difficulties arise from both the complexity of the interventions themselves and from different organisational settings in individual hospitals. The second part specifically describes the implementation of patient safety improvement programmes in Switzerland and discusses measures intended to bridge the gap between the theory and practice of implementation in Switzerland. Then, the national pilot programme to improve patient safety in surgery is presented, which was launched by the federal Swiss government and has been implemented by the patient safety foundation. Procedures, challenges and highlights in implementing the programme in Switzerland on a national level are outlined. Finally, first (preliminary) results are presented and critically discussed. Copyright © 2015. Published by Elsevier GmbH.

  17. In-lake Modeling Recommendation Report for Lake Champlain TMDL

    EPA Pesticide Factsheets

    This report describes the recommended modeling approach for the in-lake modeling component of the Lake Champlain TMDL project. The report was prepared by Tetra Tech, with input from the Lake Champlain modeling workgroup. (TetraTech, 2012b)

  18. Euthanasia and assisted suicide: comparison of legal aspects in Switzerland and other countries.

    PubMed

    Burkhardt, S; La Harpe, R; Harding, T W; Sobel, J

    2006-10-01

    The purpose of this paper is to present the legal aspects associated with assisted suicide in Switzerland and compare them with those in other countries. Like euthanasia, assisted suicide is a subject that induces much discussion in many countries. While the law is very liberal in some countries, such as Belgium and the Netherlands (where both euthanasia and assisted suicide take place), these practices are very controversial in other countries, such as France, where they remain taboo subjects. In the United States of America, the laws concerning assisted suicide can differ greatly from one state to another. For example, in Oregon, assisted suicide is allowed if applied by a medical doctor; in others, this act is illegal. In Canada, it is punishable according to the Criminal Code. In Switzerland euthanasia is punishable by law. However, the penal code does not condemn assisted suicide, whether carried out by a medical doctor or another person, provided it is not carried out through selfish motives. The application of these practices has become simplified in recent years and societies for the right to die with dignity based on this principle have come into being (Exit and Dignitas). In the French- and German-speaking parts of Switzerland the association Exit assists individuals living in Switzerland with serious progressive and incurable disease in their engagement to end their life. The association Dignitas, in the German-speaking part of Switzerland, also undertakes--in the same circumstances--to assist individuals coming from foreign countries. Dignitas welcomes several such individuals every year, especially from Germany, where a similar approach does not currently exist.

  19. Water quality of Lake Austin and Town Lake, Austin, Texas

    USGS Publications Warehouse

    Andrews, Freeman L.; Wells, Frank C.; Shelby, Wanda J.; McPherson, Emma

    1988-01-01

    Water-quality data collected from Lake Austin and Town Lake, following runoff, generally were not adequate to fully determine the effects of runoff on the lakes. Data collection should not to be limited to fixed-station sampling following runoff, and both lakes need to be sampled simultaneously as soon as possible following significant precipitation.

  20. Bathymetry of Bonnie Doone Lake, Kornbow Lake, Mintz Pond, and Glenville Lake, Cumberland County, North Carolina, 1996-98

    USGS Publications Warehouse

    Giorgino, M.J.; Strain, R.E.

    1999-01-01

    Bathymetric surveys were conducted at four water-supply impoundments of Little Cross Creek in Cumberland County, North Carolina. The surveys were conducted in April 1996 at Mintz Pond and Glenville Lake, and in January 1998 at Bonnie Doone Lake and Kornbow Lake. The resulting bathymetric maps are the first to cover the entire range in depth for these reservoirs and provide a framework for future evaluations of bathymetry and storage capacity. Bathymetric maps were constructed from depth and position data collected at each reservoir. A boat-mounted, research-grade fathometer was used to record water depths with a vertical accuracy of 0.1 foot. At Mintz Pond and Glenville Lake, position was measured by using a wide-band laser tracking system interfaced with a total station survey instrument. This positioning method required multiple land-based control points to be established and was hampered by line-of-sight restrictions between the control points and the boat. At Bonnie Doone Lake and Kornbow Lake, a global positioning system was used to collect differentially corrected location data. This positioning method enabled more rapid data collection, eliminated the need for land-based control points, and provided improved data coverage. Spillway elevations range from 172.8 feet above mean sea level at Bonnie Doone Lake to 113.1 feet at Glenville Lake. Surface area and storage volume were computed for each reservoir and were related to water-surface elevations at 1-foot intervals. The combined surface acreage of the four Little Cross Creek reservoirs at their full-pool elevations is 120.97 acres, consisting of 21.20 acres at Bonnie Doone Lake, 47.09 acres at Kornbow Lake, 15.56 acres at Mintz Pond, and 37.12 acres at Glenville Lake. The four reservoirs have a combined usable storage capacity of 674.91 acre-feet, which is the sum of 127.93 acre-feet in Bonnie Doone Lake, 320.62 acre-feet in Kornbow Lake, 53.25 acre-feet in Mintz Pond, and 173.11 acre-feet in Glenville Lake.

  1. Vocational Education in Switzerland: Facts, Figures and Prospects.

    ERIC Educational Resources Information Center

    Haefeli, Kurt

    Vocational education (VE) in Switzerland is characterized by diversity and pragmatism and is shaped by the country's geography, political system, economy, and culture. Roughly two-thirds of all Swiss youth participate in some form of vocational training at the upper secondary level. Vocational certificates and higher vocational certificates can…

  2. [Remedy for shortage or risk for national security? The search for oil in Switzerland].

    PubMed

    Haller, Lea; Gisler, Monika

    2014-03-01

    Over several decades, geologists, entrepreneurs, politicians, and public authorities dealt with a potential petroleum occurrence in Switzerland. They provided scientific expertise, granted concessions, invested capital and sank bore holes. Although the endeavour was never successful economically, it reveals how closely related geopolitical situations and the exploitation of natural resources were. This article investigates the search for crude oil in Switzerland from the 1930s until the 1960s, combining a history of science and technology perspective with a history of the political regulations and economic considerations concerning the extractive industry. It traces the changing fears and hopes about potential oil occurrences in Switzerland: From an investment to overcome future shortages, to the risk of imperial desires if oil would be found in abundance.

  3. Lake trout in the Great Lakes: Basin-wide stock collapse and binational restoration

    USGS Publications Warehouse

    Hansen, Michael J.; Taylor, William W.; Ferreri, C. Paola

    1999-01-01

    The lake trout (Salvelinus namaycush) was important to the human settlement of each of the Great Lakes, and underwent catastrophic collapses in each lake in the nineteenth and twentieth centuries. The timing of lake trout stock collapses were different in each lake, as were the causes of the collapses, and have been the subject of much scientific inquiry and debate. The purpose of this chapter is to summarize and review pertinent information relating historical changes in Great Lakes lake trout stocks, binational efforts to restore those stocks, and progress toward stock restoration. This presentation attempts to generalize patterns across the Great Lakes, rather than to focus within each lake. Lake specific analyses have been used to understand lake specific causes and effects, but there is continuing debate about some of these causes and effects. A basinwide review may suggest mechanisms for observed changes that are not evident by lake specific analysis.

  4. GloboLakes: A global observatory of lake responses to environmental change.

    NASA Astrophysics Data System (ADS)

    Groom, Steve; Tyler, Andrew; Hunter, Peter; Spyrakos, Evangelos; Martinez-Vicente, Victor; Merchant, Chris; Cutler, Mark; Rowan, John; Dawson, Terry; Maberly, Stephen; Cavalho, Laurence; Elliot, Alex; Thackery, Stephen; Miller, Claire; Scott, Marian

    2014-05-01

    The world's freshwater ecosystems are vital components of the global biosphere, yet are vulnerable to climate and other human-induced change. There is increasing recognition that lakes play an important role in global biogeochemical cycling and provide key ecosystem services. However, our understanding of how lakes respond to environmental change at a global scale, and how this impacts on their status and function, is hampered by limited information on their chemical, physical and ecological condition. There are estimated to be over 300 million lakes globally, of which over 17,000 are greater than 10 km2 in surface area. These numbers have limited the systematic study of lake ecosystems. GloboLakes is a five-year UK research programme investigating the state of lakes and their response to climatic and other environmental drivers of change. It will establish a satellite-based observatory with archive and near-real time data processing to produce a time series of observed biogeochemical parameters and lake temperature for over 1000 lakes globally. This will be supported by linked ancillary data on climate and catchment land-use. The ability to monitor a large number of lakes consistently at high frequency and globally will facilitate a paradigm shift in our understanding of how lakes respond to environmental change at different spatial and temporal scales. A key requirement is to validate satellite retrieval algorithms and test the time-series of resulting lake properties such as chlorophyll-a by comparison with in situ data. To support the former extensive bio-optical and constituent data were taken in year 1 of the project in a number of UK lakes with a variety of trophic states. Furthermore, for wider validation activities GloboLakes has established the LIMNADES initiative to create a centralised database of ground bio-optical measurements of worldwide lakes through voluntary cooperation across the international scientific community. This presentation will

  5. Cost distribution of bluetongue surveillance and vaccination programmes in Austria and Switzerland (2007–2016)

    PubMed Central

    Pinior, Beate; Loitsch, Angelika; Stockreiter, Simon; Hutter, Sabine; Richter, Veronika; Lebl, Karin; Schwermer, Heinzpeter; Käsbohrer, Annemarie

    2018-01-01

    Bluetongue virus (BTV) is an emerging transboundary disease in Europe, which can cause significant production losses among ruminants. The analysis presented here assessed the costs of BTV surveillance and vaccination programmes in Austria and Switzerland between 2007 and 2016. Costs were compared with respect to time, type of programme, geographical area and who was responsible for payment. The total costs of the BTV vaccination and surveillance programmes in Austria amounted to €23.6 million, whereas total costs in Switzerland were €18.3 million. Our analysis demonstrates that the costs differed between years and geographical areas, both within and between the two countries. Average surveillance costs per animal amounted to approximately €3.20 in Austria compared with €1.30 in Switzerland, whereas the average vaccination costs per animal were €6.20 in Austria and €7.40 in Switzerland. The comparability of the surveillance costs is somewhat limited, however, due to differences in each nation’s surveillance (and sampling) strategy. Given the importance of the export market for cattle production, investments in such programmes are more justified for Austria than for Switzerland. The aim of the retrospective assessment presented here is to assist veterinary authorities in planning and implementing cost-effective and efficient control strategies for emerging livestock diseases. PMID:29363572

  6. Mortality atlas of the main causes of death in Switzerland, 2008-2012.

    PubMed

    Chammartin, Frédérique; Probst-Hensch, Nicole; Utzinger, Jürg; Vounatsou, Penelope

    2016-01-01

    Analysis of the spatial distribution of mortality data is important for identification of high-risk areas, which in turn might guide prevention, and modify behaviour and health resources allocation. This study aimed to update the Swiss mortality atlas by analysing recent data using Bayesian statistical methods. We present average pattern for the major causes of death in Switzerland. We analysed Swiss mortality data from death certificates for the period 2008-2012. Bayesian conditional autoregressive models were employed to smooth the standardised mortality rates and assess average patterns. Additionally, we developed models for age- and gender-specific sub-groups that account for urbanisation and linguistic areas in order to assess their effects on the different sub-groups. We describe the spatial pattern of the major causes of death that occurred in Switzerland between 2008 and 2012, namely 4 cardiovascular diseases, 10 different kinds of cancer, 2 external causes of death, as well as chronic respiratory diseases, Alzheimer's disease, diabetes, influenza and pneumonia, and liver diseases. In-depth analysis of age- and gender-specific mortality rates revealed significant disparities between urbanisation and linguistic areas. We provide a contemporary overview of the spatial distribution of the main causes of death in Switzerland. Our estimates and maps can help future research to deepen our understanding of the spatial variation of major causes of death in Switzerland, which in turn is crucial for targeting preventive measures, changing behaviours and a more cost-effective allocation of health resources.

  7. Watershed vs. within-lake drivers of nitrogen: phosphorus dynamics in shallow lakes.

    PubMed

    Ginger, Luke J; Zimmer, Kyle D; Herwig, Brian R; Hanson, Mark A; Hobbs, William O; Small, Gaston E; Cotner, James B

    2017-10-01

    Research on lake eutrophication often identifies variables affecting amounts of phosphorus (P) and nitrogen (N) in lakes, but understanding factors influencing N:P ratios is important given its influence on species composition and toxin production by cyanobacteria. We sampled 80 shallow lakes in Minnesota (USA) for three years to assess effects of watershed size, proportion of watershed as both row crop and natural area, fish biomass, and lake alternative state (turbid vs. clear) on total N : total P (TN : TP), ammonium, total dissolved phosphorus (TDP), and seston stoichiometry. We also examined N:P stoichiometry in 20 additional lakes that shifted states during the study. Last, we assessed the importance of denitrification by measuring denitrification rates in sediment cores from a subset of 34 lakes, and by measuring seston δ 15 N in four additional experimental lakes before and after they were experimentally manipulated from turbid to clear states. Results showed alternative state had the largest influence on overall N:P stoichiometry in these systems, as it had the strongest relationship with TN : TP, seston C:N:P, ammonium, and TDP. Turbid lakes had higher N at given levels of P than clear lakes, with TN and ammonium 2-fold and 1.4-fold higher in turbid lakes, respectively. In lakes that shifted states, TN was 3-fold higher in turbid lakes, while TP was only 2-fold higher, supporting the notion N is more responsive to state shifts than is P. Seston δ 15 N increased after lakes shifted to clear states, suggesting higher denitrification rates may be important for reducing N levels in clear states, and potential denitrification rates in sediment cores were among the highest recorded in the literature. Overall, our results indicate lake state was a primary driver of N:P dynamics in shallow lakes, and lakes in clear states had much lower N at a given level of P relative to turbid lakes, likely due to higher denitrification rates. Shallow lakes are often

  8. Changes in Rongbuk lake and Imja lake in the Everest region of Himalaya

    NASA Astrophysics Data System (ADS)

    Chen, W.; Doko, T.; Liu, C.; Ichinose, T.; Fukui, H.; Feng, Q.; Gou, P.

    2014-12-01

    The Himalaya holds the world record in terms of range and elevation. It is one of the most extensively glacierized regions in the world except the Polar Regions. The Himalaya is a region sensitive to climate change. Changes in the glacial regime are indicators of global climate changes. Since the second half of the last century, most Himalayan glaciers have melted due to climate change. These changes directly affected the changes of glacial lakes in the Himalayan region due to the glacier retreat. New glacial lakes are formed, and a number of them have expanded in the Everest region of the Himalayas. This paper focuses on the two glacial lakes which are Imja Lake, located at the southern slope, and Rongbuk Lake, located at the northern slope in the Mt. Everest region, Himalaya to present the spatio-temporal changes from 1976 to 2008. Topographical conditions between two lakes were different (Kruskal-Wallis test, p < 0.05). Rongbuk Lake was located at 623 m higher than Imja Lake, and radiation of Rongbuk Lake was higher than the Imja Lake. Although size of Imja Lake was larger than the Rongbuk Lake in 2008, the growth speed of Rongbuk Lake was accelerating since 2000 and exceeds Imja Lake in 2000-2008. This trend of expansion of Rongbuk Lake is anticipated to be continued in the 21st century. Rongbuk Lake would be the biggest potential risk of glacial lake outburst flood (GLOF) at the Everest region of Himalaya in the future.

  9. Antimicrobial susceptibility of Brachyspira hyodysenteriae in Switzerland.

    PubMed

    Kirchgässner, C; Schmitt, S; Borgström, A; Wittenbrink, M M

    2016-06-01

    Brachyspira (B.) hyodysenteriae is the causative agent of swine dysentery (SD), a severe mucohaemorrhagic diarrheal disease in pigs worldwide. So far, the antimicrobial susceptibility patterns of B. hyodysenteriae in Switzerland have not been investigated. Therefore, a panel of 30 porcine B. hyodysenteriae isolates were tested against 6 antimicrobial agents by using the VetMIC Brachy panel, a broth microdilution test. Tiamulin and valnemulin showed high antimicrobial activity inhibiting all isolates at low concentrations. The susceptibility testing of doxycycline revealed values from ≤0.25 μg/ ml (47%) to 2 μg/ml (10%). The MIC values of lincomycin ranged between ≤0.5 μg/ml (30%) and 32 μg/ml (43%). For tylosin, 57% of the isolates could not be inhibited at the highest concentration of ≥128 μg/ml. The MIC values for tylvalosin were between ≤0.25 μg/ml (10%) and 8 μg/ml (20%). These findings reveal Switzerland's favourable situation compared to other European countries. Above all, tiamulin and valnemulin are still effective antimicrobial agents and can be further used for the treatment of SD.

  10. 78 FR 17097 - Safety Zone; Lake Havasu Triathlon; Lake Havasu City, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-20

    ...-AA00 Safety Zone; Lake Havasu Triathlon; Lake Havasu City, AZ AGENCY: Coast Guard, DHS. ACTION... waters of Lake Havasu and the London Bridge Channel for the Lake Havasu Triathlon. This temporary safety... participants. The waterside swim course consists of 1500 meters in Lake Havasu and the London Bridge Channel...

  11. Competition between larval lake herring (Coregonus artedi) and lake whitefish (Coregonus clupeaformis) for zooplankton

    USGS Publications Warehouse

    Davis, Bruce M.; Todd, Thomas N.

    1998-01-01

    Diet and growth of larval lake herring (Coregonus artedi) and lake whitefish (Coregonus clupeaformis) were compared in mesocosm experiments in a small mesotrophic lake in southeastern Michigan. Fish were sampled from single-species and mixed assemblages in 2-m3 cages for 8 weeks during April and May. Both species initially ate mostly cyclopoid copepodites and small cladocerans (Bosmia spp.). Schoener's index of diet overlap showed considerable overlap (70-90%). Lake whitefish ate Daphnia spp. and adult copepods about 2 weeks earlier than did lake herring, perhaps related to their larger mean mouth gape. Lake whitefish were consistently larger than lake herring until the eighth week, especially in the sympatric treatments. Lake whitefish appeared to have a negative effect on the growth of lake herring, as lake herring in mixed-species treatments were smaller and weighed less than lake herring reared in single-species treatments. The diet similarities of lake whitefish and lake herring larvae could make them competitors for food in the Great Lakes. The greater initial size of lake whitefish could allow them to eat larger prey earlier and thereby limit availability of these prey to lake herring at a crucial period of development.

  12. The Morphometry of Lake Palmas, a Deep Natural Lake in Brazil

    PubMed Central

    Barroso, Gilberto F.; Gonçalves, Monica A.; Garcia, Fábio da C.

    2014-01-01

    Lake Palmas (A = 10.3km2) is located in the Lower Doce River Valley (LDRV), on the southeastern coast of Brazil. The Lake District of the LDRV includes 90 lakes, whose basic geomorphology is associated with the alluvial valleys of the Barreiras Formation (Cenozoic, Neogene) and with the Holocene coastal plain. This study aimed to investigate the relationship of morphometry and thermal pattern of a LDRV deep lake, Lake Palmas. A bathymetric survey carried out in 2011 and the analysis of hydrographic and wind data with a geographic information system allowed the calculation of several metrics of lake morphometry. The vertical profiling of physical and chemical variables in the water column during the wet/warm and dry/mild cold seasons of 2011 to 2013 has furnished a better understanding of the influence of the lake morphometry on its structure and function. The overdeepened basin has a subrectangular elongated shape and is aligned in a NW-SE direction in an alluvial valley with a maximum depth (Zmax) of 50.7m, a volume of 2.2×108 m3 (0.22km3) and a mean depth (Zmv) of 21.4m. These metrics suggest Lake Palmas as the deepest natural lake in Brazil. Water column profiling has indicated strong physical and chemical stratification during the wet/warm season, with a hypoxic/anoxic layer occupying one-half of the lake volume. The warm monomictic pattern of Lake Palmas, which is in an accordance to deep tropical lakes, is determined by water column mixing during the dry and mild cold season, especially under the influence of a high effective fetch associated with the incidence of cold fronts. Lake Palmas has a very long theoretical retention time, with a mean of 19.4 years. The changes observed in the hydrological flows of the tributary rivers may disturb the ecological resilience of Lake Palmas. PMID:25406062

  13. Embryotoxicity of Great Lakes lake trout extracts to developing rainbow trout

    USGS Publications Warehouse

    Wright, Peggy J.; Tillitt, Donald E.

    1999-01-01

    Planar halogenated hydrocarbons (PHHs), such as polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls are present in aquatic systems, and are known to produce adverse effects in fish. This study investigated the embryotoxicity of PHH mixtures through the nanoinjection of environmental extracts into newly fertilized eggs from two strains of rainbow trout. Organic extracts were obtained from whole adult lake trout collected from Lake Michigan in 1988 and Lake Superior in 1994. The graded doses of the final extracts used for injection were quantified as 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic-equivalents (TEQs) based on the concentrations of dioxins, furans and non-o-PCBs in each, and as equivalent amounts found in the eggs of the original lake trout (eggEQ). Total TEQs in the lake trout were 14.7 pg TEQ/g in the Lake Michigan sample and 7.3 pg TEQ/g in the Lake Superior sample. The extract of the Lake Michigan lake trout was embryotoxic to rainbow trout; LD50 values were 35 eggEQ (15–90, 95% F.L.) in the Arlee strain and 14 eggEQ (5–99, 95% F.L.) in the Erwin strain of rainbow trout. The LD50 values of the Lake Michigan extract in either of these strains of rainbow trout fall within the actual range of TCDD LD50values based on TEQs. This indicates that an additive model of toxicity is appropriate to quantify PHHs in relation to early life stage mortality in fish. Gross lesions characteristic of exposure to PHHs (i.e. yolk-sac edema, craniofacial deformities, and hemorrhaging) increased in a dose-related manner. The lowest observable adverse effect concentrations (LOAEC) for these gross lesions and cumulative mortalities suggests that current concentrations of PHHs in lake trout from Lake Michigan are above a threshold for adverse effects and these compounds may have implications on the lack of recruitment in certain Great Lakes lake trout populations.

  14. Great Lakes

    NASA Image and Video Library

    2017-12-08

    Bands of lake effect snow drift eastward from the western Great Lakes in this true-color image captured by the NOAA/NASA Suomi NPP satellite's Visible Infrared Imaging Radiometer Suite (VIIRS) instrument on January 5, 2017. National Weather Service forecasters expect light to moderate lake effect snow showers to continue throughout the day today and into Saturday (1/7). Lake-effect snow forms when cold air passes over the warmer waters of a lake. This causes some lake water to evaporate into the air and warm it. This warmer, wetter air rises and cools as it moves away from the lake. When it cools, it releases that moisture and, if it’s cold enough, that moisture turns into snow. Although true-color images like this may appear to be photographs of Earth, they aren't. They are created by combining data from the three color channels on the VIIRS instrument sensitive to the red, green and blue (or RGB) wavelengths of light into one composite image. In addition, data from several other channels are often also included to cancel out or correct atmospheric interference that may blur parts of the image. Credit: NOAA/NASA/Suomi NPP via NOAA's Environmental Visualization Laboratory

  15. Lake Michigan lake trout PCB model forecast post audit

    EPA Science Inventory

    Scenario forecasts for total PCBs in Lake Michigan (LM) lake trout were conducted using the linked LM2-Toxics and LM Food Chain models, supported by a suite of additional LM models. Efforts were conducted under the Lake Michigan Mass Balance Study and the post audit represents th...

  16. Water-quality and lake-stage data for Wisconsin lakes, water year 2005

    USGS Publications Warehouse

    Rose, W.J.; Garn, H.S.; Goddard, G.L.; Marsh, S.B.; Olson, D.L.; Robertson, Dale M.

    2006-01-01

    The U.S. Geological Survey (USGS), in cooperation with local and other agencies, collects data at selected lakes throughout Wisconsin. These data, accumulated over many years, provide a data base for developing an improved understanding of the water quality of lakes. The purpose of this report is to provide information about the chemical and physical charac-teristics of Wisconsin lakes. Data that have been collected at specific lakes, and information to aid in the interpretation of those data, are included in this report. Data collected include measure-ments of in-lake water quality and lake stage. Time series graphs of Secchi depths, surface total phosphorus and chlorophyll a concentrations collected during non-frozen periods are included for all lakes. Graphs of vertical profiles of temperature, dissolved oxygen, pH, and specific conductance are included for sites where these parameters were measured. Descriptive infor-mation for each lake includes: location of the lake, area of the lake's watershed, period for which data are available, revisions to previously published records, and pertinent remarks.

  17. Using Satellite Imagery to Monitor the Major Lakes; Case Study Lake Hamun

    NASA Astrophysics Data System (ADS)

    Norouzi, H.; Islam, R.; Bah, A.; AghaKouchak, A.

    2015-12-01

    Proper lakes function can ease the impact of floods and drought especially in arid and semi-arid regions. They are important environmentally and can directly affect human lives. Better understanding of the effect of climate change and human-driven changes on lakes would provide invaluable information for policy-makers and local people. As part of a comprehensive study, we aim to monitor the land-cover/ land-use changes in the world's major lakes using satellite observations. As a case study, Hamun Lake which is a pluvial Lake, also known as shallow Lake, located on the south-east of Iran and adjacent to Afghanistan, and Pakistan borders is investigated. The Lake is the main source of resources (agriculture, fishing and hunting) for the people around it and politically important in the region since it is shared among three different countries. The purpose of the research is to find the Lake's area from 1972 to 2015 and to see if any drought or water resources management has affected the lake. Analyzing satellites imagery from Landsat shows that the area of the Lake changes seasonally and intra-annually. Significant seasonal effects are found in 1975,1977, 1987, 1993, 1996, 1998, 2000, 2009 and 2011, as well as, substantial amount of shallow water is found throughout the years. The precipitation records as well as drought historical records are studied for the lake's basin. Meteorological studies suggest that the drought, decrease of rainfalls in the province and the improper management of the Lake have caused environmental, economic and geographical consequences. The results reveal that lake has experienced at least two prolong dryings since 1972 which drought cannot solely be blamed as main forcing factor.Proper lakes function can ease the impact of floods and drought especially in arid and semi-arid regions. They are important environmentally and can directly affect human lives. Better understanding of the effect of climate change and human-driven changes on lakes

  18. A coupled lake-atmosphere model (CLAM) and its application to Lake Kinneret

    NASA Astrophysics Data System (ADS)

    Pan, Hai

    1999-08-01

    Kinneret is a 166-km2 lake located in Northern Israel, in the central part of the Jordan Valley, a corridor running from north to south, between the Galilee hills in the west and the Golan Heights in the east. Both the Galilee hills and the Golan Heights reach an elevation of about 400 m above mean sea level (MSL), and the lake is about -210 m (MSL). North of the lake is the mountainous area of the Hermon, culminating at about 2800 m (MSL). About 120 km south of it is the Dead Sea, which is about -410 m (MSL), and about 45 km west of it is the Mediterranean Sea. The complexity of the terrain, combined with relatively arid soil and various ground covers surrounding the lake, results in a very complicated system of atmospheric and lake processes. To understand this system, especially the processes affecting the atmosphere and lake dynamics and thermodynamics, and their effects on Lake Kinneret evaporation, a coupled lake-atmosphere model (CLAM) was developed and applied to the lake region. The CLAM is based on the Regional Atmospheric Modeling System (RAMS) and the oceanic S-coordinate Rutgers University Model (SCRUM). Energy, mass, and momentum are conserved at the interface between the atmosphere and the lake, and appropriate balance equations are applied there. In the atmospheric module, two nested grids are employed to simulate Northern Israel at a resolution of 4 x 4 km2, and the near-lake region at a resolution of 1 x 1 km 2. Synoptic conditions obtained from the National Meteorological Center (NMC) reanalysis are assimilated by the model. Soil moisture, which appears to have a significant impact on atmospheric circulation in this region, was transformed from the normalized difference vegetation index (NDVI). Observations collected during two summers above and inside the lake emphasize the good capability of CLAM to simulate surface fluxes and other microclimatic conditions, as well as lake temperature and currents. Although the lake is small (about 12-km wide

  19. Bathymetric Surveys of Lake Arthur and Raccoon Lake, Pennsylvania, June 2007

    USGS Publications Warehouse

    Hittle, Clinton D.; Ruby, A. Thomas

    2008-01-01

    In spring of 2007, bathymetric surveys of two Pennsylvania State Park lakes were performed to collect accurate data sets of lake-bed elevations and to develop methods and techniques to conduct similar surveys across the state. The lake-bed elevations and associated geographical position data can be merged with land-surface elevations acquired through Light Detection and Ranging (LIDAR) techniques. Lake Arthur in Butler County and Raccoon Lake in Beaver County were selected for this initial data-collection activity. In order to establish accurate water-surface elevations during the surveys, benchmarks referenced to NAVD 88 were established on land at each lake by use of differential global positioning system (DGPS) surveys. Bathymetric data were collected using a single beam, 210 kilohertz (kHz) echo sounder and were coupled with the DGPS position data utilizing a computer software package. Transects of depth data were acquired at predetermined intervals on each lake, and the shoreline was delineated using a laser range finder and compass module. Final X, Y, Z coordinates of the geographic positions and lake-bed elevations were referenced to NAD 83 and NAVD 88 and are available to create bathymetric maps of the lakes.

  20. Comparison of catch and lake trout bycatch in commercial trap nets and gill nets targeting lake whitefish in northern Lake Huron

    USGS Publications Warehouse

    Johnson, James E.; Ebener, Mark P.; Gebhardt, Kenneth; Bergstedt, Roger

    2004-01-01

    We compared seasonal lake whitefish catch rates, lake trout bycatch, and gearinduced lake trout mortality between commercial trap nets and gill nets in north-central Lake Huron. Onboard monitors recorded catches from 260 gill net and 96 trap net lifts from October 1998 through December 1999. Catch rates for lake whitefish were highest in fall for both gear types, reflecting proximity of spawning sites to the study area. Lake whitefish catch rates were also relatively high in spring but low in both gear types in summer. Lake trout were the principal bycatch species in both gears. The lake trout bycatch was lowest in both gear types in fall, highest in gill nets in spring, and highest in trap nets in summer. The ratio of lake trout to legal whitefish (the target species) was highest in summer and lowest in fall in both gear types. The high lake trout ratio in summer was due principally to low catch rates of lake whitefish. All but 3 of 186 live lake trout removed from trap net pots survived for at least two days of observation in laboratory tanks. Therefore, we estimated that post-release survival of trap netted lake trout that had not been entangled in the mesh was 98.4%. In addition, we accounted for stress-induced mortality for lake trout that were live at capture but entangled in the mesh of either gear type. Resulting estimates of lake trout survival were higher in trap nets (87.8%) than in gill nets (39.6%). The number of lake trout killed per lift was highest during summer in trap nets and during spring in gill nets. In trap nets, 85% of dead lake trout were observed to be entangled in the mesh of the pot or tunnels. Survival rates of lake trout in gill nets were higher in our study than reported by others, probably because our nets were hand lifted in a small boat. Our trap net-induced mortality estimates on lake trout were higher than those reported by others because we adjusted our estimates to account for post-release mortality caused by handling and

  1. Lake levels, streamflow, and surface-water quality in the Devils Lake area, North Dakota

    USGS Publications Warehouse

    Wiche, Gregg J.

    1996-01-01

    The Devils Lake Basin is a 3,810-square-mile (mi2) closed basin (fig. 1) in the Red River of the North Basin. About 3,320 mi2 of the total 3,810 mi2 is tributary to Devils Lake; the remainder is tributary to Stump Lake.Since glaciation, the lake level of Devils Lake has fluctuated from about 1,457 feet (ft) above sea level (asl), the natural spill elevation of the lake to the Sheyenne River, to 1,400 ft asl (Aronow, 1957). Although no documented records of lake levels are available before 1867, Upham (1895, p. 595), on the basis of tree-ring chronology, indicated that the lake level was 1,441 ft asl in 1830. Lake levels were recorded sporadically from 1867 to 1901 when the U.S. Geological Survey established a gaging station on Devils Lake. From 1867 to the present (1996), the lake level has fluctuated between a maximum of 1,438.4 ft asl in 1867 and a minimum of 1,400.9 ft asl in 1940 (fig. 2). On July 31, 1996, the lake level was 1,437.8 ft asl, about 15.2 ft higher than the level recorded in February 1993 and the highest level in about 120 years.Since 1993, the lake level of Devils Lake (fig. 2) has risen rapidly in response to above-normal precipitation from the summer of 1993 to the present, and 30,000 acres of land around the lake have been flooded. The above-normal precipitation also has caused flooding elsewhere in the Devils Lake Basin. State highways near Devils Lake are being raised, and some local roads have been closed because of flooding.In response to the flooding, the Devils Lake Basin Interagency Task Force, comprised of many State and Federal agencies, was formed in 1995 to find and propose intermediate (5 years or less) solutions to reduce the effects of high lake levels. In addition to various planning studies being conducted by Federal agencies, the North Dakota State Water Commission has implemented a project to store water on small tracts of land and in the chain of lakes (Sweetwater Lake, Morrison Lake, Dry Lake, Mikes Lake, Chain Lake

  2. Bovine besnoitiosis in Switzerland: imported cases and local transmission.

    PubMed

    Basso, Walter; Lesser, Maren; Grimm, Felix; Hilbe, Monika; Sydler, Titus; Trösch, Luzia; Ochs, Hansueli; Braun, Ueli; Deplazes, Peter

    2013-12-06

    Bovine besnoitiosis is an economically important disease of cattle, caused by Besnoitia besnoiti (Protozoa, Apicomplexa). A considerable spreading of this parasitic infection has been observed in Europe in the last ten years, mainly related to animal trade. In order to investigate the possibility of B. besnoiti being unnoticed introduced and getting established in Switzerland through the import of breeding cattle from France, a total of 767 animals (650 cattle imported from France and 117 cattle that had contact with B. besnoiti positive cattle in Swiss farms) were screened for antibodies against B. besnoiti by both a commercial ELISA and by the indirect fluorescent antibody test (IFAT). A total of 101 (13.17%) samples showed a positive reaction in ELISA (cut-off: percent of positivity [PP] ≥ 15) and 16 (2.09%) samples had IFAT titers ≥ 1:100. Eight of those samples reacted positive in Western blot (WB), corresponding to five imported Limousin cattle (two cows and one bull from France and two cows from Germany) and to three cattle born in Switzerland (one Limousin heifer born from one of the positive German cows, and two adult Braunvieh cows, that had been in contact with one of the French cows at a Swiss farm). Seven of those animals were subclinically infected and one animal showed only very mild signs. They were subsequently slaughtered, and the serological diagnosis could be confirmed by real-time PCR and/or histopathology in seven animals. The most frequent parasite localizations were the tendons and surrounding connective tissue of the distal limbs and the skin of the head region. Furthermore, B. besnoiti could be successfully isolated in vitro from one French, one German and one Swiss cattle (isolates Bb-IPZ-1-CH, Bb-IPZ-2-CH and Bb-IPZ-3-CH). In the current situation in Switzerland, prophylactic and control measures should include a serological examination of cattle to be imported from endemic areas and the culling of all confirmed positive animals from

  3. Genetic diversity of Diporeia in the Great Lakes: comparison of Lake Superior to the other Great Lakes

    EPA Science Inventory

    Abundances of Diporeia have dropped drastically in the Great Lakes, except in Lake Superior, where data suggest that population counts actually have risen. Various ecological, environmental, or geographic hypotheses have been proposed to explain the greater abundance of Lake Supe...

  4. Water-quality and lake-stage data for Wisconsin lakes, water year 1996

    USGS Publications Warehouse

    ,

    1997-01-01

    The purpose of this report is to provide information about the physical and chemical characteristics of Wisconsin lakes. Data that have been collected at specific lakes, and information to aid in the interpretation of those data, are included in this report. Data collected includes measurements of lake stage and in-lake water quality. Graphs of Secchi depths, surface totalphosphorus and chlorophyll-a concentrations versus time are included for lakes with two or more years of data. Graphs of vertical profiles of temperature, dissolved oxygen, pH, and specific conductance are included for sites where these parameters were measured. Descriptive information for each lake includes: location of the lake, drainage area of the lake's watershed, period for which data are available, revisions to previously published records, and pertinent remarks. Additional data, such as streamflow and water quality in tributary and outlet streams of some of the lakes, are published in another volume: "Water Resources Data-Wisconsin, 1996."

  5. Red blood cell use in Switzerland: trends and demographic challenges

    PubMed Central

    Volken, Thomas; Buser, Andreas; Castelli, Damiano; Fontana, Stefano; Frey, Beat M.; Rüsges-Wolter, Ilka; Sarraj, Amira; Sigle, Jörg; Thierbach, Jutta; Weingand, Tina; Taleghani, Behrouz Mansouri

    2018-01-01

    Background Several studies have raised concerns that future demand for blood products may not be met. The ageing of the general population and the fact that a large proportion of blood products is transfused to elderly patients has been identified as an important driver of blood shortages. The aim of this study was to collect, for the first time, nationally representative data regarding blood donors and transfusion recipients in order to predict the future evolution of blood donations and red blood cell (RBC) use in Switzerland between 2014 and 2035. Materials and methods Blood donor and transfusion recipient data, subdivided by the subjects’ age and gender were obtained from Regional Blood Services and nine large, acute-care hospitals in various regions of Switzerland. Generalised additive regression models and time-series models with exponential smoothing were employed to estimate trends of whole blood donations and RBC transfusions. Results The trend models employed suggested that RBC demand could equal supply by 2018 and could eventually cause an increasing shortfall of up to 77,000 RBC units by 2035. Discussion Our study highlights the need for continuous monitoring of trends of blood donations and blood transfusions in order to take proactive measures aimed at preventing blood shortages in Switzerland. Measures should be taken to improve donor retention in order to prevent a further erosion of the blood donor base. PMID:27723455

  6. Epidemiological study of pestiviruses in South American camelids in Switzerland.

    PubMed

    Mudry, M; Meylan, M; Regula, G; Steiner, A; Zanoni, R; Zanolari, P

    2010-01-01

    In the context of the ongoing eradication campaign for bovine viral diarrhea virus (BVDV) in cattle in Switzerland, the role of South American camelids (SAC) as a possible virus reservoir needed to be evaluated. To assess and characterize the prevalence of pestivirus infections in SAC in Switzerland. Serum samples collected from 348 animals (40 herds) in 2008 and from 248 animals (39 herds) in 2000 were examined for antibodies against pestiviruses and for the presence of BVDV viral RNA. Cross-sectional study using stratified, representative herd sampling. An indirect BVDV-ELISA was used to analyze serum samples for pestivirus antibodies, and positive samples underwent a serum neutralization test (SNT). Real-time RT-PCR to detect pestiviral RNA was carried out in all animals from herds with at least 1 seropositive animal. In 2008, the overall prevalence of animals positive for antibodies (ELISA) and pestiviral RNA or was 5.75 and 0%, respectively. In 2000, the corresponding prevalences were 3.63 and 0%, respectively. The seroprevalences (SNT) for BVDV, border disease virus or undetermined pestiviruses were estimated to be 0, 1.73, and 4.02% in 2008, and 0.40, 1.21, and 2.02% in 2000, respectively. At the present time, SAC appear to represent a negligible risk of re-infection for the BVDV eradication program in cattle in Switzerland. Copyright © 2010 by the American College of Veterinary Internal Medicine.

  7. Carbon balance indicates a time limit for cultivation of organic soils in central Switzerland

    NASA Astrophysics Data System (ADS)

    Paul, Sonja; Ammann, Christof; Alewell, Christine; Leifeld, Jens

    2016-04-01

    Peatlands serve as important carbon sinks. Globally, more than 30% of the soil organic carbon is stored in organic soils, although they cover only 3% of the land surface. The agricultural use of organic soils usually requires drainage thereby transforming these soils from a net carbon sink into a net source. Currently, about 2 to 3 Gt CO2 are emitted world-wide from degrading organic soils (Joosten 2011; Parish et al. 2008) which is ca. 5% of the total anthropogenic emissions. Besides these CO2 emissions, the resulting subsidence of drained peat soils during agricultural use requires that drainage system are periodically renewed and finally to use pumping systems after progressive subsidence. In Switzerland, the Seeland region is characterised by fens which are intensively used for agriculture since 1900. The organic layer is degrading and subsequently getting shallower and the underlying mineral soil, as lake marl or loam, is approaching the surface. The questions arises for how long and under which land use practises and costs these soils can be cultivated in the near future. The study site was under crop rotation until 2009 when it was converted to extensively used grassland with the water regime still being regulated. The soil is characterised by a degraded organic horizon of 40 to 70 cm. Since December 2014 we are measuring the carbon exchange of this grassland using the Eddy-Covariance method. For 2015, the carbon balance indicates that the degraded fen is a strong carbon source, with approximately 500 g C m-2 a-1. The carbon balance is dominated by CO2 emissions and harvest. Methane emissions are negligible. With the gained emission factors different future scenarios are evaluated for the current cultivation practise of organic soils in central Switzerland. Joosten, H., 2011: Neues Geld aus alten Mooren: Über die Erzeugung von Kohlenstoffzertifikaten aus Moorwiedervernässungen. Telma Beiheft 4, 183-202. Parish, F., A. Sirin, D. Charman, H. Joosten, T

  8. Delineation of sympatric morphotypes of lake trout in Lake Superior

    USGS Publications Warehouse

    Moore, Seth A.; Bronte, Charles R.

    2001-01-01

    Three morphotypes of lake trout Salvelinus namaycush are recognized in Lake Superior: lean, siscowet, and humper. Absolute morphotype assignment can be difficult. We used a size-free, whole-body morphometric analysis (truss protocol) to determine whether differences in body shape existed among lake trout morphotypes. Our results showed discrimination where traditional morphometric characters and meristic measurements failed to detect differences. Principal components analysis revealed some separation of all three morphotypes based on head and caudal peduncle shape, but it also indicated considerable overlap in score values. Humper lake trout have smaller caudal peduncle widths to head length and depth characters than do lean or siscowet lake trout. Lean lake trout had larger head measures to caudal widths, whereas siscowet had higher caudal peduncle to head measures. Backward stepwise discriminant function analysis retained two head measures, three midbody measures, and four caudal peduncle measures; correct classification rates when using these variables were 83% for leans, 80% for siscowets, and 83% for humpers, which suggests the measures we used for initial classification were consistent. Although clear ecological reasons for these differences are not readily apparent, patterns in misclassification rates may be consistent with evolutionary hypotheses for lake trout within the Laurentian Great Lakes.

  9. LakeMIP Kivu: Evaluating the representation of a large, deep tropical lake by a set of 1-dimensional lake models

    NASA Astrophysics Data System (ADS)

    Thiery, Wim; Stepanenko, Viktor; Darchambeau, François; Joehnk, Klaus; Martynov, Andrey; Mironov, Dmitrii; Perroud, Marjorie; van Lipzig, Nicole

    2013-04-01

    The African great lakes are of utmost importance for the local economy (fishing), as well as being essential to the survival of the local people. During the last decades, these lakes experienced fast changes in ecosystem structure and functioning and their future evolution is a major concern. In this study, for the first time a set of one-dimensional lake models are evaluated over East-Africa, in particular over Lake Kivu (2.28 °S; 28.98 °E). The unique limnology of meromictic Lake Kivu, with the importance of salinity and geothermal springs in a tropical high-altitude climate, presents a worthy challenge to the 1D-lake models currently involved in the Lake Model Intercomparison Project (LakeMIP). Furthermore, this experiment will serve as the basis for a future, more complex intercomparison, coupling lake models with atmospheric circulation models to analyse climate change effects on the lake. Meteorological observations from two automatic weather stations, one at Kamembe airport (Rwanda, 2003-2008), the other at ISP Bukavu (DRC, 2003-2011), are used to drive each of these models. For the evaluation, a unique dataset is used which contains over 150 temperature profiles recorded since 2002. The standard LakeMIP protocol is adapted to mirror the limnological conditions in Lake Kivu and to unify model parameters as far as possible. Since some lake models do not account for salinity and its effect upon lake stratification, two sets of simulations are performed with each model: one for the freshwater layer only (60 m) and one for the average lake depth (240 m) including salinity. Therewith, on the one hand it is investigated whether each model is able to reproduce the correct mixing regime in Lake Kivu and captures the controlling of this seasonality by the relative humidity, which constrains evaporation except during summer (JJA). On the other hand, the ability of different models to simulate salinity- and geothermal-induced effects upon deep water stratification is

  10. Planetary Lake Lander - A Robotic Sentinel to Monitor a Remote Lake

    NASA Technical Reports Server (NTRS)

    Pedersen, Liam; Smith, Trey; Lee, Susan; Cabrol, Nathalie; Rose, Kevin

    2012-01-01

    The Planetary Lake Lander Project is studying the impact of rapid deglaciation at a high altitude alpine lake in the Andes, where disrupted environmental, physical, chemical, and biological cycles result in newly emerging natural patterns. The solar powered Lake Lander robot is designed to monitor the lake system and characterize both baseline characteristics and impacts of disturbance events such as storms and landslides. Lake Lander must use an onboard adaptive science-on-the-fly approach to return relevant data about these events to mission control without exceeding limited energy and bandwidth resources. Lake Lander carries weather sensors, cameras and a sonde that is winched up and down the water column to monitor temperature, dissolved oxygen, turbidity and other water quality parameters. Data from Lake Lander is returned via satellite and distributed to an international team of scientists via web-based ground data systems. Here, we describe the Lake Lander Project scientific goals, hardware design, ground data systems, and preliminary data from 2011. The adaptive science-on-the-fly system will be described in future papers.

  11. Patterns of organochlorine contamination in lake trout from Wisconsin waters of the Great Lakes

    USGS Publications Warehouse

    Miller, Michael A.; Madenjian, Charles P.; Masnado, Robert G.

    1992-01-01

    To investigate spatial and temporal patterns of organochlorine contamination in lake trout from Wisconsin waters of the Great Lakes, we examined laboratory contaminant analysis data of muscle tissue samples from Lake Michigan (n=317) and Lake Superior (n=53) fish. Concentrations of polychlorinated biphenyls (PCBs), chlordane, and dieldrin, reported as mg/kg wet weight in 620 mm to 640 mm mean length Lake Michigan lake trout, decreased over time. Mean total PCB concentration declined exponentially from 9.7 in 1975 to 1.9 in 1990. Total chlordane concentration declined 63 percent from 0.48 in 1983 to 0.18 in 1990, and dieldrin declined 52 percent during this same period, from 0.21 to 0.10. The bioaccumulation rate of PCBs is significantly lower for lake trout inhabiting Lake Michigan's midlake reef complex, compared to lake trout from the nearshore waters of western Lake Michigan. Organochlorine compound concentrations were greater in Lake Michigan lake trout than Lake Superior fish. Lake Superior lean lake trout and siscowet exhibited similar rates of PCB bioaccumulation despite major differneces in muscle tissue lipid content between the two subspecies. The lack of a significant difference in the PCB bioaccumulation rates of lean trout and siscowet suggests that lipid content may not be an important factor influencing PCB bioaccumulation in lake trout, within the range of lipid concentrations observed. Relative concentrations of the various organochlorine contaminants found in lake trout were highly correlated, suggesting similar mass balance processes for these compounds. Evidence presented revealing spatial and temporal patterns of organochlorine contamination may be of value in reestablishing self-sustaining populations of lake trout in Lake Michigan.

  12. Winter diet of lake herring (Coregonus artedi) in western Lake Superior

    USGS Publications Warehouse

    Link, Jason; Selgeby, James H.; Hoff, Michael H.; Haskell, Craig

    1995-01-01

    Lake herring (Coregonus artedi) and zooplankton samples were simultaneously collected through the ice in the Apostle Islands region of western Lake Superior to provide information on the winter feeding ecology of lake herring. Zooplankton constituted the entire diet of the 38 lake herring collected for this study. We found no evidence of piscivory, although it has been reported by anglers. Diet selectivities were calculated using a Wilcoxon signed-ranks test and showed a preference of lake herring for larger zooplankton, especially Diaptomus sicilis, whereas the smaller copepod,Cyclops bicuspidatus thomasi, and immature copepod stages were selected against. These data document that overwintering copepods are food for a broad size range of lake herring in winter.

  13. Mono Lake, California

    NASA Image and Video Library

    2017-03-24

    In eastern California, along the western edge of the Great Basin, sits Mono Lake. This is a salty remnant of a wetter era. Estimates are that the lake existed for at least 760,000 years. Now surrounded by mountain ranges, however, Mono Lake has no outlet; water entering the lake can only evaporate away, so Mono Lake is saltier than the ocean. South of the lake appear some of the geologic features known as Mono Craters. Geologists estimate that the Mono Craters last erupted about 650 years ago. The image was acquired July 7, 2016, covers an area of 22.6 by 34 km, and is located at 37.9 degrees north, 119 degrees west. http://photojournal.jpl.nasa.gov/catalog/PIA21518

  14. Synthetic Musk Fragrances in Lake Erie and Lake Ontario Sediment Cores

    PubMed Central

    Peck, Aaron M.; Linebaugh, Emily K.; Hornbuckle, Keri C.

    2009-01-01

    Two sediment cores collected from Lake Ontario and Lake Erie were sectioned, dated, and analyzed for five polycyclic musk fragrances and two nitro musk fragrances. The polycyclic musk fragrances were HHCB (Galaxolide), AHTN (Tonalide), ATII (Traseolide), ADBI (Celestolide), and AHMI (Phantolide). The nitro musk fragrances were musk ketone and musk xylene. Chemical analysis was performed by gas chromatography/mass spectrometry (GC/MS) and results from Lake Erie were confirmed using gas chromatography/triple-quadrupole mass spectrometry (GC/MS/MS). The chemical signals observed at the two sampling locations were different from each other due primarily to large differences in the sedimentation rates at the two sampling locations. HHCB was detected in the Lake Erie core while six compounds were detected in the Lake Ontario core. Using measured fragrance and 210Pb activity, the burden of synthetic musk fragrances estimated from these sediment cores is 1900 kg in Lake Erie and 18000 kg in Lake Ontario. The input of these compounds to the lakes is increasing. The HHCB accumulation rates in Lake Erie for 1979-2003 and 1990-2003 correspond to doubling times of 16 ± 4 yr and 8 ± 2 yr, respectively. The results reflect current U.S. production trends for the sum of all fragrance compounds. PMID:17007119

  15. Analysis, results and conclusion of magnetotelluric data acquired in northern Switzerland

    NASA Astrophysics Data System (ADS)

    Shah, Neeraj; Samrock, Friedemann; Grayver, Alexander; Saar, Martin O.

    2017-04-01

    In early 2016, a magnetotelluric (MT) survey of the Aargau region of northern Switzerland was performed in order to understand the potential of the magnetotelluric method to characterise the electrical resistivity properties of the subsurface in Switzerland, and more widely, in areas with high amounts of cultural electromagnetic (EM) noise. Subsurface electrical resisitivity properties are interesting as they can help identify underground aquifers or geothermal resources and possibly provide insight into the large-scale movement of fluid. The north of Switzerland is a challenging and representative environment, with significant EM infrastructure, including powerlines and numerous other sources of noise related to human activity and use of industrial equipment. Here, we present the results of the survey together with detailed analysis of the issues encountered and challenges faced when doing this survey. In particular, we concentrate on data quality issues in the raw time series, the impact of using a remote reference over single site processing and the distribution of transfer functions. The final set of transfer functions for the survey, which includes twelve successful sites, is shown to suffer from noise issues in certain frequency ranges. A 1-D inversion of SSQ averaged transfer functions and comparison to existing borehole data demonstrates that geologic data is captured in the MT data recorded in northern Switzerland. Further, 2-D forward modelling supports the idea that good geologic information exists in the data despite the noise issues, which for now, impede a robust multi-dimensional inversion. Finally, suggestions for future work and methods to improve the quality of data when surveying in high EM noise environments are offered with a view to being able to reliably perform MT surveys closer to urban environments.

  16. Status of lake trout rehabilitation in the Northern Refuge of Lake Michigan

    USGS Publications Warehouse

    Madenjian, Charles P.; DeSorcie, Timothy J.

    1999-01-01

    The Northern Refuge in Lake Michigan was established in 1985 as part of a rehabilitation program to stock yearling lake trout Salvelinus namaycush in areas with the best potential for success. Stocking of hatchery-reared lake trout within the refuge began in 1986 at three reefs: Boulder Reef, Gull Island Reef, and Richards Reef. On each reef from 1991 to 1997 we conducted gill-net surveys during the fall spawning season to evaluate performance of adult lake trout, and we conducted beam trawl surveys for naturally reproduced age-0 lake trout in the spring. Criteria to evaluate performance included spawner density, growth, maturity, and mortality. We found no evidence of natural reproduction by lake trout from our surveys. Nevertheless, density of spawning lake trout on Boulder Reef (69 fish/305 m of gill net/night) and Gull Island Reef (34 fish/305 m of gill net/night) appeared to be sufficiently high to initiate a self-sustaining population. Growth and maturity rates of lake trout in the Northern Refuge were similar to those for lake trout stocked in the nearshore region of Lake Michigan. In the Northern Refuge, growth rate for the Marquette strain of lake trout was slightly higher than for the Lewis Lake strain. Annual mortality estimates from catch curve analyses ranged from 0.46 to 0.41, and therefore, these estimates approached a level that was considered to be sufficiently low to allow for a self-sustaining population. Thus, it appeared that the lack of evidence for natural reproduction by lake trout in the Northern Refuge should not be attributed to inability of the population to attain a sufficiently large stock of spawners.

  17. Water-Quality and Lake-Stage Data for Wisconsin Lakes, Water Year 2007

    USGS Publications Warehouse

    Wisconsin Water Science Center Lake-Studies Team: Rose, W. J.; Garn, H.S.; Goddard, G.L.; Marsh, S.B.; Olson, D.L.; Robertson, Dale M.

    2008-01-01

    The U.S. Geological Survey (USGS), in cooperation with local and other agencies, collects data at selected lakes throughout Wisconsin. These data, accumulated over many years, provide a data base for developing an improved understanding of the water quality of lakes. To make these data available to interested parties outside the USGS, the data are published annually in this report series. The locations of water-quality and lake-stage stations in Wisconsin for water year 2007 are shown in figure 1. A water year is the 12-month period from October 1 through September 30. It is designated by the calendar year in which it ends. Thus, the period October 1, 2005 through September 30, 2007 is called 'water year 2007.' The purpose of this report is to provide information about the chemical and physical characteristics of Wisconsin lakes. Data that have been collected at specific lakes, and information to aid in the interpretation of those data, are included in this report. Data collected include measurements of in-lake water quality and lake stage. Time series of Secchi depths, surface total phosphorus and chlorophyll a concentrations collected during non-frozen periods are included for all lakes. Graphs of vertical profiles of temperature, dissolved oxygen, pH, and specific conductance are included for sites where these parameters were measured. Descriptive information for each lake includes: location of the lake, area of the lake?s watershed, period for which data are available, revisions to previously published records, and pertinent remarks. Additional data, such as streamflow and water quality in tributary and outlet streams of some of the lakes, are published in another volume: 'Water Resources Data-Wisconsin, 2007.'

  18. 42. Peaks of Otter, Abbott Lake. View across lake to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    42. Peaks of Otter, Abbott Lake. View across lake to peaks of Outter Lodge, completed in 1964. Construction of the lake got underway in 1964. Looking east-northeast. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  19. Patterns of egg deposition by lake trout and lake whitefish at Tawas artificial Reef, Lake Huron, 1990-1993

    USGS Publications Warehouse

    Foster, N.R.; Kennedy, G.W.; Munawar, M.; Edsall, T.; Leach, J.

    1995-01-01

    In August 1987, the Michigan Department of Natural Resources (MDNR), with the help and co-sponsorship of Walleyes for Iosco County, constructed Tawas artificial reef to improve recreational fishing in Tawas Bay. Post-construction assessment in October, 1987, by the MDNR found twice as many adult lake trout in a gill net set on the reef as in a similar net set off the reef, indicating that lake trout already had begun to investigate this new habitat. Similar netting efforts in October 1989 caught three times as many adults on the reef as off it, even though the on-reef net was set for less than one third as long a period. Using a remotely operated vehicle (ROV), we detected prespawning aggregations of lake trout on the reef in fall 1989, and MDNR biologists set emergent fly traps on the reef in April-May 1990-1991. These fry traps captured several newly emerged lake trout and lake whitefish fry, demonstrating that eggs of both species has hatched successfully. Gill netting in 1992-1993 by U.S. Fish and Wildlife Service biologists netted large numbers of ripe lake trout in late October and ripe lake whitefish in early to mid-November. The purpose of this paper is to describe the relative quantities of eggs deposited and the spatial patterns of egg deposition by lake trout and lake whitefish at Tawas artificial reef during 1990-1993.

  20. Lake Powell

    NASA Image and Video Library

    2007-09-20

    The white ring around Lake Powell tells the story. The surface is down 98 feet. This is critical, because Powell, Lake Mead, and other lakes along the Colorado River provide water for millions of people in five states. We are in the eighth year of a drought on the Colorado River. This year was the driest year ever reported in Southern California, and there is a severe drought in Northern California, down to less than 30-percent of snow pack. This ASTER image of part of Lake Powell was acquired in 2001. The gray area depicts the shrunken, reduced 2007 lake extent compared to the extended, larger black area in 2001. The image covers an area of 24 x 30 km, and is centered near 37.1 degrees north latitude, 111.3 degrees west longitude. This image from NASA Terra satellite. http://photojournal.jpl.nasa.gov/catalog/PIA10614

  1. National Lakes Assessment: A Collaborative Survey of the Nation's Lakes

    EPA Science Inventory

    The National Lakes Assessment A Collaborative Survey of the Nation's Lakes presents the results of an unprecedented assessment of the nation’s lakes. This report is part of the National Aquatic Resource Surveys, a series of statistically based surveys designed to provide the pub...

  2. Integrated care organizations in Switzerland.

    PubMed

    Berchtold, Peter; Peytremann-Bridevaux, Isabelle

    2011-01-01

    The Swiss health care system is characterized by its decentralized structure and high degree of local autonomy. Ambulatory care is provided by physicians working mainly independently in individual private practices. However, a growing part of primary care is provided by networks of physicians and health maintenance organizations (HMOs) acting on the principles of gatekeeping. The share of insured choosing an alternative (managed care) type of basic health insurance and therefore restrict their choice of doctors in return for lower premiums increased continuously since 1990. To date, an average of one out of eight insured person in Switzerland, and one out of three in the regions in north-eastern Switzerland, opted for the provision of care by general practitioners in one of the 86 physician networks or HMOs. About 50% of all general practitioners and more than 400 other specialists have joined a physician networks. Seventy-three of the 86 networks (84%) have contracts with the healthcare insurance companies in which they agree to assume budgetary co-responsibility, i.e., to adhere to set cost targets for particular groups of patients. Within and outside the physician networks, at regional and/or cantonal levels, several initiatives targeting chronic diseases have been developed, such as clinical pathways for heart failure and breast cancer patients or chronic disease management programs for patients with diabetes. Swiss physician networks and HMOs were all established solely by initiatives of physicians and health insurance companies on the sole basis of a healthcare legislation (Swiss Health Insurance Law, KVG) which allows for such initiatives and developments. The relevance of these developments towards more integration of healthcare as well as their implications for the future are discussed.

  3. Hydrology of the Lake Deaton and Lake Okahumpka area, Northeast Sumter County, Florida

    USGS Publications Warehouse

    Simonds, Edward P.; German, E.R.

    1980-01-01

    The Floridan aquifer in the Lake Deaton and Lake Okahumpka area is 50 to 130 feet below land surface. During the 16-year period 1963-78 lake evaporation exceeded rainfall by 0.4 inches. Drainage from Lake Deaton and its surrounding area goes into Chitty Chatty Creek and on the Hogeye Sink when the altitude of the potentiometric surface of the Floridan aquifer is low. During a higher altitude of the Floridan potentiometric surface, Hogeye Sink may discharge water; this water, along with the normal runoff, goes into Lake Okahumpka. Average lake fluctuation is 1.5 to 2.0 feet per year. Lake Deaton supports a large population of blue-green algae and Lake Okahumpka is choked with aquatic plants. The water quality of the two lakes differ, with Lake Deaton having a sodium chloride water and Lake Okahumpka having a calcium bicarbonate water. Analysis of water and bottom material samples showed that only cadmium and mercury exceeded the Florida Department of Environmental Regulation 's criteria for Class III waters; however, the amounts detected were at or slightly above the limits of the analytical method. (USGS)

  4. Strand-plain evidence for late Holocene lake-level variations in Lake Michigan

    USGS Publications Warehouse

    Thompson, T.A.; Baedke, S.J.

    1997-01-01

    Lake level is a primary control on shoreline behavior in Lake Michigan. The historical record from lake-level gauges is the most accurate source of information on past lake levels, but the short duration of the record does not permit the recognition of long-term patterns of lake-level change (longer than a decade or two). To extend the record of lake-level change, the internal architecture and timing of development of five strand plains of late Holocene beach ridges along the Lake Michigan coastline were studied. Relative lake-level curves for each site were constructed by determining the elevation of foreshore (swash zone) sediments in the beach ridges and by dating basal wetland sediments in the swales between ridges. These curves detect long-term (30+ yr) lake-level variations and differential isostatic adjustments over the past 4700 yr at a greater resolution than achieved by other studies. The average timing of beach-ridge development for all sites is between 29 and 38 yr/ridge. This correspondence occurs in spite of the embayments containing the strand plains being different in size, orientation, hydrographic regime, and available sediment type and caliber. If not coincidental, all sites responded to a lake-level fluctuation of a little more than three decades in duration and a range of 0.5 to 0.6 m. Most pronounced in the relative lake-level curves is a fluctuation of 120-180 yr in duration. This ???150 yr variation is defined by groups of four to six ridges that show a rise and fall in foreshore elevations of 0.5 to 1.5 m within the group. The 150 yr variation can be correlated between sites in the Lake Michigan basin. The ???30 and 150 yr fluctuations are superimposed on a long-term loss of water to the Lake Michigan basin and differential rates of isostatic adjustment.

  5. Annually-layered lake sediments reveal strongly increased release of persistent chemicals due to accelerated glacier melting

    NASA Astrophysics Data System (ADS)

    Anselmetti, Flavio S.; Blüthgen, Nancy; Bogdal, Christian; Schmid, Peter

    2010-05-01

    Melting glaciers may represent a secondary source of chemical pollutants that have previously been incorporated and stored in the ice. Of particular concern are persistent organic pollutants (POPs), such as the insecticide dichlorodiphenyl trichloroethane (DDT) and industrial chemicals like polychlorinated biphenyls (PCBs), which are hazardous environmental contaminants due to their persistent, bioaccumulative and toxic properties. They were introduced in the 1930s and eventually banned in the 1970s. After release into the environment these chemicals were atmospherically transported to even remote areas such as the Alps and were deposited and stored in glaciers. Ongoing drastic glacier melting due to global warming, which is expected to further accelerate, implies the significance of studying the fate of these 'legacy pollutants'. Proglacial lake sediments provide well-dated and high-resolution archives to reconstruct timing and quantities of such a potentially hazardous remobilization. The goal of this study is to reconstruct the historical inputs of POPs into remote alpine lakes and to investigate the accelerated release of POPs from melting glaciers. Due to their lipophilic character, these chemicals exhibit a high tendency to adsorb to particles whereas concentrations in water are expected to be low. Therefore, quantitative determination in annually-layered lake sediment provides an excellent way to investigate the temporal trend of inputs into lakes that act as particle sinks. For this purpose, sediment cores were sampled from proglacial lakes in the Bernese Alps (Switzerland), which are exclusively fed by glacial melt waters. For comparison, cores were also taken from nearby high-alpine lakes located in non-glaciated catchments, which only should record the initial atmospheric fall-out. Sediment layers were dated by annual varve counting and radionuclide measurements; they cover the time period from the mid 20th century to today. The measured time series of

  6. A scaling theory for number-flux distributions generated during steady-state coagulation and settling and application to particles in Lake Zurich, Switzerland.

    PubMed

    Boehm, Alexandria B

    2002-10-15

    In this study, we extend the established scaling theory for cluster size distributions generated during unsteady coagulation to number-flux distributions that arise during steady-state coagulation and settling in an unmixed water mass. The scaling theory predicts self-similar number-flux distributions and power-law decay of total number flux with depth. The shape of the number-flux distributions and the power-law exponent describing the decay of the total number flux are shown to depend on the homogeneity and small i/j limit of the coagulation kernel and the exponent kappa, which describes the variation in settling velocity with cluster volume. Particle field measurements from Lake Zurich, collected by U. Weilenmann and co-workers (Limnol. Oceanogr.34, 1 (1989)), are used to illustrate how the scaling predictions can be applied to a natural system. This effort indicates that within the mid-depth region of Lake Zurich, clusters of the same size preferentially interact and large clusters react with one another more quickly than small ones, indicative of clusters coagulating in a reaction-limited regime.

  7. Water-Quality and Lake-Stage Data for Wisconsin Lakes, Water Year 2006

    USGS Publications Warehouse

    Rose, W.J.; Garn, H.S.; Goddard, G.L.; Marsh, S.B.; Olson, D.L.; Robertson, Dale M.

    2007-01-01

    The U.S. Geological Survey (USGS), in cooperation with local and other agencies, collects data at selected lakes throughout Wisconsin. These data, accumulated over many years, provide a data base for developing an improved understanding of the water quality of lakes. To make these data available to interested parties outside the USGS, the data are published annually in this report series. The locations of water-quality and lake-stage stations in Wisconsin for water year 2006 are shown in figure 1. A water year is the 12-month period from October 1 through September 30. It is designated by the calendar year in which it ends. Thus, the period October 1, 2005 through September 30, 2006 is called 'water year 2006.' The purpose of this report is to provide information about the chemical and physical characteristics of Wisconsin lakes. Data that have been collected at specific lakes, and information to aid in the interpretation of those data, are included in this report. Data collected include measurements of in-lake water quality and lake stage. Time series of Secchi depths, surface total phosphorus and chlorophyll a concentrations collected during non-frozen periods are included for all lakes. Graphs of vertical profiles of temperature, dissolved oxygen, pH, and specific conductance are included for sites where these parameters were measured. Descriptive information for each lake includes: location of the lake, area of the lake's watershed, period for which data are available, revisions to previously published records, and pertinent remarks. Additional data, such as streamflow and water quality in tributary and outlet streams of some of the lakes, are published in another volume: 'Water Resources Data-Wisconsin, 2006.' Water-resources data, including stage and discharge data at most streamflow-gaging stations, are available through the World Wide Web on the Internet. The Wisconsin Water Science Center's home page is at http://wi.water.usgs.gov/. Information on the

  8. Optimization of a large-scale microseismic monitoring network in northern Switzerland

    NASA Astrophysics Data System (ADS)

    Kraft, Toni; Mignan, Arnaud; Giardini, Domenico

    2013-10-01

    We have developed a network optimization method for regional-scale microseismic monitoring networks and applied it to optimize the densification of the existing seismic network in northeastern Switzerland. The new network will build the backbone of a 10-yr study on the neotectonic activity of this area that will help to better constrain the seismic hazard imposed on nuclear power plants and waste repository sites. This task defined the requirements regarding location precision (0.5 km in epicentre and 2 km in source depth) and detection capability [magnitude of completeness Mc = 1.0 (ML)]. The goal of the optimization was to find the geometry and size of the network that met these requirements. Existing stations in Switzerland, Germany and Austria were considered in the optimization procedure. We based the optimization on the simulated annealing approach proposed by Hardt & Scherbaum, which aims to minimize the volume of the error ellipsoid of the linearized earthquake location problem (D-criterion). We have extended their algorithm to: calculate traveltimes of seismic body waves using a finite difference ray tracer and the 3-D velocity model of Switzerland, calculate seismic body-wave amplitudes at arbitrary stations assuming the Brune source model and using scaling and attenuation relations recently derived for Switzerland, and estimate the noise level at arbitrary locations within Switzerland using a first-order ambient seismic noise model based on 14 land-use classes defined by the EU-project CORINE and open GIS data. We calculated optimized geometries for networks with 10-35 added stations and tested the stability of the optimization result by repeated runs with changing initial conditions. Further, we estimated the attainable magnitude of completeness (Mc) for the different sized optimal networks using the Bayesian Magnitude of Completeness (BMC

  9. Diet and prey selection by Lake Superior lake trout during springs 1986-2001

    USGS Publications Warehouse

    Ray, B.A.; Hrabik, T.R.; Ebener, M.P.; Gorman, O.T.; Schreiner, D.R.; Schram, S.T.; Sitar, S.P.; Mattes, W.P.; Bronte, C.R.

    2007-01-01

    We describe the diet and prey selectivity of lean (Salvelinus namaycush namaycush) and siscowet lake trout (S. n. siscowet) collected during spring (April–June) from Lake Superior during 1986–2001. We estimated prey selectivity by comparing prey numerical abundance estimates from spring bottom trawl surveys and lake trout diet information in similar areas from spring gill net surveys conducted annually in Lake Superior. Rainbow smelt (Osmerus mordax) was the most common prey and was positively selected by both lean and siscowet lake trout throughout the study. Selection by lean lake trout for coregonine (Coregonus spp.) prey increased after 1991 and corresponded with a slight decrease in selection for rainbow smelt. Siscowet positively selected for rainbow smelt after 1998, a change that was coincident with the decrease in selection for this prey item by lean lake trout. However, diet overlap between lean and siscowet lake trout was not strong and did not change significantly over the study period. Rainbow smelt remains an important prey species for lake trout in Lake Superior despite declines in abundance.

  10. Biology, population structure, and estimated forage requirements of lake trout in Lake Michigan

    USGS Publications Warehouse

    Eck, Gary W.; Wells, LaRue

    1983-01-01

    Data collected during successive years (1971-79) of sampling lake trout (Salvelinus namaycush) in Lake Michigan were used to develop statistics on lake trout growth, maturity, and mortality, and to quantify seasonal lake trout food and food availability. These statistics were then combined with data on lake trout year-class strengths and age-specific food conversion efficiencies to compute production and forage fish consumption by lake trout in Lake Michigan during the 1979 growing season (i.e., 15 May-1 December). An estimated standing stock of 1,486 metric tons (t) at the beginning of the growing season produced an estimated 1,129 t of fish flesh during the period. The lake trout consumed an estimated 3,037 t of forage fish, to which alewives (Alosa pseudoharengus) contributed about 71%, rainbow smelt (Osmerus mordax) 18%, and slimy sculpins (Cottus cognatus) 11%. Seasonal changes in bathymetric distributions of lake trout with respect to those of forage fish of a suitable size for prey were major determinants of the size and species compositions of fish in the seasonal diet of lake trout.

  11. Lakes and lake-like waters of the Hawaiian Archipelago

    USGS Publications Warehouse

    Maciolek, J.A.

    1982-01-01

    This summary of Hawaiian lacustrine limnology is based on 12 years of field and literature surveys of archipelagic inland waters. Lakes here are distinguished from other standing waters by limits on surface oceanic area (> 0.1 ha) and depth (> 2 m), and by the absence of flatural surface oceanic connection. A variety of extinct and existing water bodies, sometimes referred to as lakes, are noted. Six lakes are described. Five of them are in crater basins, 3 are freshwater, and 2 are elevated (highest = 3969 m). The scarcity of elevated lakes results from general permeability of the substrata. Among the 6 lakes, surface areas range from 0.22 to 88 ha and maximum depths from 3 to 248 m. Naturally occurring aquatic biota generally is low in species diversity except for phytoplankton; fishes and submersed vascular plants are absent. Two lowland lakes, freshwater Green (Wai a Pele) and saline Kauhak6, are described for the first time. Profundal Kauhak6, 248 m deep, has a surface area of only 0.35 ha, which results in an extraordinary relative depth of 370%. It is permanently stratified, a condition apparently due primarily to the unique morphometry of its basin. 

  12. Lake Powell

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The white ring around Lake Powell tells the story. The surface is down 98 feet. This is critical, because Powell, Lake Mead, and other lakes along the Colorado River provide water for millions of people in five states. We are in the eighth year of a drought on the Colorado River. This year was the driest year ever reported in Southern California, and there is a severe drought in Northern California, down to less than 30-percent of snow pack. This ASTER image of part of Lake Powell was acquired in 2001. The gray area depicts the shrunken, reduced 2007 lake extent compared to the extended, larger black area in 2001.

    The image covers an area of 24 x 30 km, and is centered near 37.1 degrees north latitude, 111.3 degrees west longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  13. Two large earthquakes in western Switzerland in the sixteenth century: 1524 in Ardon (VS) and 1584 in Aigle (VD)

    NASA Astrophysics Data System (ADS)

    Schwarz-Zanetti, Gabriela; Fäh, Donat; Gache, Sylvain; Kästli, Philipp; Loizeau, Jeanluc; Masciadri, Virgilio; Zenhäusern, Gregor

    2018-03-01

    The Valais is the most seismically active region of Switzerland. Strong damaging events occurred in 1755, 1855, and 1946. Based on historical documents, we discuss two known damaging events in the sixteenth century: the 1524 Ardon and the 1584 Aigle earthquakes. For the 1524, a document describes damage in Ardon, Plan-Conthey, and Savièse, and a stone tablet at the new bell tower of the Ardon church confirms the reconstruction of the bell tower after the earthquake. Additionally, a significant construction activity in the Upper Valais churches during the second quarter of the sixteenth century is discussed that however cannot be clearly related to this event. The assessed moment magnitude Mw of the 1524 event is 5.8, with an error of about 0.5 units corresponding to one standard deviation. The epicenter is at 46.27 N, 7.27 E with a high uncertainty of about 50 km corresponding to one standard deviation. The assessed moment magnitude Mw of the 1584 main shock is 5.9, with an error of about 0.25 units corresponding to one standard deviation. The epicenter is at 46.33 N and 6.97 E with an uncertainty of about 25 km corresponding to one standard deviation. Exceptional movements in the Lake Geneva wreaked havoc along the shore of the Rhone delta. The large dimension of the induced damage can be explained by an expanded subaquatic slide with resultant tsunami and seiche in Lake Geneva. The strongest of the aftershocks occurred on March 14 with magnitude 5.4 and triggered a destructive landslide covering the villages Corbeyrier and Yvorne, VD.

  14. Ciscoes (Coregonus, subgenus Leucichthys) of the Laurentian Great Lakes and Lake Nipigon

    USGS Publications Warehouse

    Eshenroder, Randy L.; Vecsei, Paul; Gorman, Owen T.; Yule, Daniel; Pratt, Thomas C.; Mandrak, Nicholas E.; Bunnell, David B.; Muir, Andrew M.

    2016-01-01

    This study of the ciscoes (Coregonus, subgenus Leucichthys) of the Great Lakes and Lake Nipigon represents a furtherance through 2015 of field research initiated by Walter Koelz in 1917 and continued by Stanford Smith in the mid-1900s—a period spanning nearly a century. Like Koelz’s study, this work contains information on taxonomy, geographical distribution, ecology, and status of species (here considered forms). Of the seven currently recognized forms (C. artedi, C. hoyi, C. johannae, C. kiyi, C. nigripinnis, C. reighardi, and C. zenithicus) described by Koelz as major in his 1929 monograph, two (C. johannae and C. reighardi) are extinct. In addition, C. alpenae, described by Koelz but subsequently synonymized with C. zenithicus, although extinct, is recognized as valid making a total of eight major forms. Six of these forms, all but C. artedi and C. hoyi, have been lost from Lake Michigan, and seven have been lost from Lake Huron, leaving in Lake Huron only C. artedi and an introgressed deepwater form that we term a hybrid swarm. C. artedi appears, like its sister form C. alpenae, to have been lost from Lake Erie. Only C. artedi remains extant in Lake Ontario, its three sister forms (C. hoyi, C. kiyi, and C. reighardi) having disappeared long ago.Lakes Superior and Nipigon have retained their original species flocks consisting of four forms each: C. artedi, C. hoyi, and C. zenithicus in both lakes; C. kiyi in Lake Superior; and C. nigripinnis in Lake Nipigon. Morphological deviations from the morphotypes described by Koelz have been modest in contemporary samples. Overall, C. kiyi and C. artedi were the most morphologically stable forms while C. hoyi, C. nigripinnis, and C. zenithicus were the least stable. Although contemporary populations of C. artedi from Lakes Michigan and Huron are highly diverged from the morphotypes described by Koelz, the contemporary samples were of undescribed deep-bodied forms unlikely to have been sampled by Koelz because of

  15. Sedimentary constraints on late Quaternary lake-level fluctuations at Bear Lake, Utah and Idaho

    USGS Publications Warehouse

    Smoot, J.P.; Rosenbaum, J.G.

    2009-01-01

    A variety of sedimentological evidence was used to construct the lake-level history for Bear Lake, Utah and Idaho, for the past ???25,000 years. Shorelines provide evidence of precise lake levels, but they are infrequently preserved and are poorly dated. For cored sediment similar to that in the modern lake, grain-size distributions provide estimates of past lake depths. Sedimentary textures provide a highly sensitive, continuous record of lake-level changes, but the modern distribution of fabrics is poorly constrained, and many ancient features have no modern analog. Combining the three types of data yields a more robust lake-level history than can be obtained from any one type alone. When smooth age-depth models are used, lake-level curves from multiple cores contain inconsistent intervals (i.e., one record indicates a rising lake level while another record indicates a falling lake level). These discrepancies were removed and the multiple records were combined into a single lake-level curve by developing age-depth relations that contain changes in deposition rate (i.e., gaps) where indicated by sedimentological evidence. The resultant curve shows that, prior to 18 ka, lake level was stable near the modern level, probably because the lake was overflowing. Between ca. 17.5 and 15.5 ka, lake level was ???40 m below the modern level, then fluctuated rapidly throughout the post-glacial interval. Following a brief rise centered ca. 15 ka ( = Raspberry Square phase), lake level lowered again to 15-20 m below modern from ca. 14.8-11.8 ka. This regression culminated in a lowstand to 40 m below modern ca. 12.5 ka, before a rapid rise to levels above modern ca. 11.5 ka. Lake level was typically lower than present throughout the Holocene, with pronounced lowstands 15-20 m below the modern level ca. 10-9, 7.0, 6.5-4.5, 3.5, 3.0-2.5, 2.0, and 1.5 ka. High lake levels near or above the modern lake occurred ca. 8.5-8.0, 7.0-6.5, 4.5-3.5, 2.5, and 0.7 ka. This lake-level history

  16. Fat content of the flesh of siscowets and lake trout from Lake Superior

    USGS Publications Warehouse

    Eschmeyer, Paul H.; Phillips, Arthur M.

    1965-01-01

    Samples of flesh were excised from the middorsal region of 67 siscowets (Salvelinus namaycush siscowet) and 46 lake trout (Salvelinus n. namaycush) collected from Lake Superior. Chemical analysis of the samples revealed a range in fat content (dry weight) of 32.5 to 88.8 per cent in siscowets and 6.6 to 52.3 per cent in lake trout. Percentage fat increased progressively with increase in length of fish in both forms, but the average rate of increase was far greater for siscowets than for lake trout at lengths between 12 and 20 inches. Despite substantial individual variation, the percentage fat in the two forms was widely different and without overlap at all comparable lengths. The range in iodine number of the fat was 100 to 160 for siscowets and 103 to 161 for lake trout; average values were generally lower for siscowets than for lake trout among fish of comparable length. Percentage fat and relative weight were not correlated significantly in either subspecies. The fat content of flesh samples from a distinctive subpopulation of Lake Superior lake trout known as 'humpers' was more closely similar to that of typical lean lake trout than to siscowets, but the rate of increase in fat with increasing length was greater than for lean lake trout. Flesh samples from hatchery-reared stocks of lake trout, hybrid lake trout X siscowets, and siscowets tended to support the view that the wide difference in fat content between siscowets and lake trout is genetically determined.

  17. Heterogeneity in testing practices for infections during pregnancy: national survey across Switzerland.

    PubMed

    Aebi-Popp, Karoline; Kahlert, Christian; Rauch, Andri; Mosimann, Beatrice; Baud, David; Low, Nicola; Surbek, Daniel

    2016-01-01

    Detection and treatment of infections during pregnancy are important for both maternal and child health. The objective of this study was to describe testing practices and adherence to current national guidelines in Switzerland. We invited all registered practicing obstetricians and gynaecologists in Switzerland to complete an anonymous web-based questionnaire about strategies for testing for 14 infections during pregnancy. We conducted a descriptive analysis according to demographic characteristics. Of 1138 invited clinicians, 537 (47.2%) responded and 520 (45.6%) were eligible as they are currently caring for pregnant women. Nearly all eligible respondents tested all pregnant women for group B streptococcus (98.0%), hepatitis B virus (HBV) (96.5%) and human immunodeficiency virus (HIV) (94.7%), in accordance with national guidelines. Although testing for toxoplasmosis is not recommended, 24.1% of respondents tested all women and 32.9% tested at the request of the patient. Hospital doctors were more likely not to test for toxoplasmosis than doctors working in private practice (odds ratio [OR] 2.52, 95% confidence interval [CI] 1.04-6.13, p = 0.04). Only 80.4% of respondents tested all women for syphilis. There were regional differences in testing for some infections. The proportion of clinicians testing all women for HIV, HBV and syphilis was lower in Eastern Switzerland and the Zurich region (69.4% and 61.2%, respectively) than in other regions (range 77.1-88.1%, p <0.001). Most respondents (74.5%) said they would appreciate national guidelines about testing for infections during pregnancy. Testing practices for infections in pregnant women vary widely in Switzerland. More extensive national guidelines could improve consistency of testing practices.

  18. 77 FR 9652 - Proposed CERCLA Administrative Cost Recovery Settlement; Lake Linden Superfund Site in Lake...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-17

    ... Settlement; Lake Linden Superfund Site in Lake Linden, Houghton County, MI AGENCY: Environmental Protection... concerning the Lake Linden Superfund Site in Lake Linden, Houghton County, Michigan with Honeywell Specialty...-6609. Comments should reference the Lake Linden Superfund Site in Lake Linden, Houghton County...

  19. Long-term simulations of dissolved oxygen concentrations in Lake Trout lakes

    NASA Astrophysics Data System (ADS)

    Jabbari, A.; Boegman, L.; MacKay, M.; Hadley, K.; Paterson, A.; Jeziorski, A.; Nelligan, C.; Smol, J. P.

    2016-02-01

    Lake Trout are a rare and valuable natural resource that are threatened by multiple environmental stressors. With the added threat of climate warming, there is growing concern among resource managers that increased thermal stratification will reduce the habitat quality of deep-water Lake Trout lakes through enhanced oxygen depletion. To address this issue, a three-part study is underway, which aims to: analyze sediment cores to understand the past, develop empirical formulae to model the present and apply computational models to forecast the future. This presentation reports on the computational modeling efforts. To this end, a simple dissolved oxygen sub-model has been embedded in the one-dimensional bulk mixed-layer thermodynamic Canadian Small Lake Model (CSLM). This model is currently being incorporated into the Canadian Land Surface Scheme (CLASS), the primary land surface component of Environment Canada's global and regional climate modelling systems. The oxygen model was calibrated and validated by hind-casting temperature and dissolved oxygen profiles from two Lake Trout lakes on the Canadian Shield. These data sets include 5 years of high-frequency (10 s to 10 min) data from Eagle Lake and 30 years of bi-weekly data from Harp Lake. Initial results show temperature and dissolved oxygen was predicted with root mean square error <1.5 °C and <3 mgL-1, respectively. Ongoing work is validating the model, over climate-change relevant timescales, against dissolved oxygen reconstructions from the sediment cores and predicting future deep-water temperature and dissolved oxygen concentrations in Canadian Lake Trout lakes under future climate change scenarios. This model will provide a useful tool for managers to ensure sustainable fishery resources for future generations.

  20. A Dynamical Downscaling study over the Great Lakes Region Using WRF-Lake: Historical Simulation

    NASA Astrophysics Data System (ADS)

    Xiao, C.; Lofgren, B. M.

    2014-12-01

    As the largest group of fresh water bodies on Earth, the Laurentian Great Lakes have significant influence on local and regional weather and climate through their unique physical features compared with the surrounding land. Due to the limited spatial resolution and computational efficiency of general circulation models (GCMs), the Great Lakes are geometrically ignored or idealized into several grid cells in GCMs. Thus, the nested regional climate modeling (RCM) technique, known as dynamical downscaling, serves as a feasible solution to fill the gap. The latest Weather Research and Forecasting model (WRF) is employed to dynamically downscale the historical simulation produced by the Geophysical Fluid Dynamics Laboratory-Coupled Model (GFDL-CM3) from 1970-2005. An updated lake scheme originated from the Community Land Model is implemented in the latest WRF version 3.6. It is a one-dimensional mass and energy balance scheme with 20-25 model layers, including up to 5 snow layers on the lake ice, 10 water layers, and 10 soil layers on the lake bottom. The lake scheme is used with actual lake points and lake depth. The preliminary results show that WRF-Lake model, with a fine horizontal resolution and realistic lake representation, provides significantly improved hydroclimates, in terms of lake surface temperature, annual cycle of precipitation, ice content, and lake-effect snowfall. Those improvements suggest that better resolution of the lakes and the mesoscale process of lake-atmosphere interaction are crucial to understanding the climate and climate change in the Great Lakes region.

  1. Survival of lake trout eggs and fry reared in water from the upper Great Lakes

    USGS Publications Warehouse

    Mac, Michael J.; Edsall, Carol Cotant; Seelye, James G.

    1985-01-01

    As part of continuing studies of the reproductive failure of lake trout (Salvelinus namaycush) in Lake Michigan, we measured the survival of lake trout eggs and fry of different origins and reared in different environments. Eggs and milt were stripped from spawning lake trout collected in the fall of 1980 from southeastern Lake Michigan, northwestern Lake Huron, south central Lake Superior, and from hatchery brood stock. Eggs from all sources were incubated, and the newly hatched fry were reared for 139 days in lake water from each of the three upper Great Lakes and in well water. Survival of eggs to hatching at all sites was lowest for those from Lake Michigan (70% of fertilized eggs) and highest for eggs from Lake Superior (96%). Comparisons of incubation water from the different lakes indicated that hatching success of eggs from all sources was highest in Lake Huron water, and lowest in Lake Michigan water. The most notable finding was the nearly total mortality of fry from eggs of southeastern Lake Michigan lake trout. At all sites, the mean survival of Lake Michigan fry through 139 days after hatching was only 4% compared to near 50% for fry from the other three sources. In a comparison of the rearing sites, little influence of water quality on fry survival was found. Thus, the poor survival was associated with the source of eggs and sperm, not the water in which the fry were reared.

  2. The most acidified Austrian lake in comparison to a neutralized mining lake

    PubMed Central

    Moser, Michael; Weisse, Thomas

    2011-01-01

    This study investigated two mining lakes located in the north of Lower Austria. These lakes arose 45 years ago when open cast lignite mining ceased. The lakes are separated by a 7-m wide dam. Due to the oxidation of pyrite, both lakes have been acidified and exhibit iron, sulphate, and heavy metal concentrations several orders of magnitude higher than in circumneutral lakes. The water column of both lakes is divided into two layers by a pronounced chemocline. The smaller mining lake (AML), with pH close to of 2.6, is the most acidic lake in Austria, whereas flooding with stream water and by drainage from the surrounding fields neutralized the adjacent larger pit lake. The goal of our study was to investigate the effect of flooding on its physical, chemical and biological properties, in comparison to the pristine AML. Even relative to other extremely acidic lakes, the flora and fauna in the AML was reduced and composed of only two flagellate, one ciliate, and one rotifer species. The simplified pelagic food web in the mixolimnion consisted of heterotrophic bacteria, the mixotrophic flagellates Chlamydomonas acidophila and Ochromonas sp., the ciliate Oxytricha sp., and the rotifer Cephalodella sp. The latter two are as yet undescribed new species. The heliozoan Actinophrys sp. that may act as top predator occurred only in low abundance. The euglenid Lepocinclis buetschlii formed a stable deep chlorophyll maximum (DCM) at 7 m depth. Highest cell numbers of L. buetschlii in the DCM exceeded 108 L−1. The neutralized mining lake harboured higher plankton diversity similar to that of natural circumneutral lakes. A peak of at least 16 different phytoplankton taxa was observed during summer. The zooplankton consisted of several copepod species, daphnids and other cladocerans, and at least six different rotifer species. Several fish species occurred in the neutralized lake. Although the effect of non-permanent flooding was largely sustainable, interannual fluctuations of

  3. Seismic Data Reveal Lake-Level Changes in Lake Issyk-Kul, Kyrgyzstan

    NASA Astrophysics Data System (ADS)

    Gebhardt, C.; Spiess, V.; Keil, H.; Sauermilch, I.; Oberhänsli, H.; Abdrakhmatov, K.; De Batist, M. A.; Naudts, L.; De Mol, L.

    2013-12-01

    Lake Issyk-Kul is located in an intramontane basin of the Tien Shan, Kyrgyzstan, Central Asia, at 1607 m above sea level. It has formed in a tectonically active region with W-E striking major thrust zones both N and S of the lake. The lake is elongated with 180 km in W-E and 60 km in S-N direction and a water depth of roughly 670 m at its central plain. With a surface area of 6232 km2 and a total water colume of around 1736 km3, Lake Issyk-Kul is the second largest lake in the higher altitudes (De Batist et al., 2002). Two large delta areas have formed at the E and W end. Steep slopes at both the N and S shore separate rather narrow, shallow shelf areas from the central deeper plain. First seismic data of lake Issyk-Kul were acquired in 1982 by the Moscow University with a total of 31 profiles across the lake. In 1997 and 2001, a second and third seismic survey of the lake were carried out by the group of Marc De Batist (Ghent, Belgium) in cooperation with the Royal Museum of Central Africa (Tervuren, Belgium) and the SBRAS (Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia) using a sparker system with a single-channel streamer. These surveys were recently completed by a fourth expedition carried out by the University of Bremen in April 2013. During this expedition, 33 additional profiles were acquired with an airgun and a multi-channel streamer. The sparker surveys mostly cover the delta and shelf areas in high detail, while the airgun survey covers the deeper parts of the lake with penetration beyond the first multiple. Bathymetry data reveal that at the delta areas, the shelf is divided into two parts. The shallower comprises the part down to 110 m water depth with an average inclination of 0.5°, while the deeper part reaches from 110 m to 300 m water depth with an average slope inclination of 1°. Incised paleo-river channels of up to 2-3 km width and 50 m depth are visible both on the eastern and western shelf, but are limited to the

  4. Natural hazard fatalities in Switzerland from 1946 to 2015

    NASA Astrophysics Data System (ADS)

    Andres, Norina; Badoux, Alexandre; Techel, Frank

    2017-04-01

    Switzerland, located in the middle of the Alps, is prone to several different natural hazards which regularly cause fatalities. To explore temporal trends as well as demographic and spatial patterns in the number of natural hazard fatalities, a database comprising all natural hazard events causing fatalities was compiled for the years 1946 until 2015. The new database includes avalanche, flood, lightning, windstorm, landslide, debris flow, rockfall, earthquake and ice avalanche processes. Two existing databases were incorporated and the resulting dataset extended by a comprehensive newspaper search. In total the database contains 635 natural hazard events causing 1023 fatalities. The database does not include victims which exposed themselves to an important danger on purpose (e.g. high risk sports). The most common causes of death were snow avalanches (37 %), followed by lightning (16 %), floods (12 %), windstorms (10 %), rockfall (8 %), landslides (7 %) and other processes (9 %). Around 14.6 fatalities occurred on average each year. A distinct decrease of natural hazard fatalities could be shown over the last 70 years, which was mostly due to the decline in the number of avalanche and lightning fatalities. Thus, nearly three times as many people were killed by natural hazard processes from 1946 to 1980 than from 1981 to 2015. Normalisation of fatality data by population resulted in a clearly declining annual crude mortality rate: 3.9 deaths per million persons for the first 35 years and 1.1 deaths per million persons for the second 35 years of the study period. The average age of the victims was approximately 36 years and about 75% were males. Most people were killed in summer (JJA, 42%) and winter (DJF, 32 %). Furthermore, almost two-thirds of the fatalities took place in the afternoon and evening. The spatial distribution of the natural hazard fatalities over Switzerland was quite homogeneous. However, mountainous parts of the country (Prealps, Alps) were

  5. Salting our freshwater lakes.

    PubMed

    Dugan, Hilary A; Bartlett, Sarah L; Burke, Samantha M; Doubek, Jonathan P; Krivak-Tetley, Flora E; Skaff, Nicholas K; Summers, Jamie C; Farrell, Kaitlin J; McCullough, Ian M; Morales-Williams, Ana M; Roberts, Derek C; Ouyang, Zutao; Scordo, Facundo; Hanson, Paul C; Weathers, Kathleen C

    2017-04-25

    The highest densities of lakes on Earth are in north temperate ecosystems, where increasing urbanization and associated chloride runoff can salinize freshwaters and threaten lake water quality and the many ecosystem services lakes provide. However, the extent to which lake salinity may be changing at broad spatial scales remains unknown, leading us to first identify spatial patterns and then investigate the drivers of these patterns. Significant decadal trends in lake salinization were identified using a dataset of long-term chloride concentrations from 371 North American lakes. Landscape and climate metrics calculated for each site demonstrated that impervious land cover was a strong predictor of chloride trends in Northeast and Midwest North American lakes. As little as 1% impervious land cover surrounding a lake increased the likelihood of long-term salinization. Considering that 27% of large lakes in the United States have >1% impervious land cover around their perimeters, the potential for steady and long-term salinization of these aquatic systems is high. This study predicts that many lakes will exceed the aquatic life threshold criterion for chronic chloride exposure (230 mg L -1 ), stipulated by the US Environmental Protection Agency (EPA), in the next 50 y if current trends continue.

  6. Morphometry and mixing regime of a tropical lake: Lake Nova (Southeastern Brazil).

    PubMed

    Gonçalves, Monica A; Garcia, Fábio C; Barroso, Gilberto F

    2016-09-01

    Lake Nova (15.5 km2) is the second largest lake in the Lower Doce River Valley (Southeastern Brazil). A better understanding of ecosystem structure and functioning requires knowledge about lake morphometry, given that lake basin form influences water column stratification. The present study aims to contribute to the understanding of relationship between morphometry and mixing patterns of deep tropical lakes in Brazil. Water column profiles of temperature and dissolved oxygen were taken on four sampling sites along the lake major axis during 2011, 2012 and 2013. The bathymetric survey was carried out in July 2011, along 131.7 km of hydrographic tracks yield 51,692 depth points. Morphometric features of lake size and form factors describe the relative deep subrectangular elongated basin with maximum length of 15.7 km, shoreline development index 5.0, volume of 0.23 km3, volume development of 1.3, and maximum, mean and relative depths of 33.9 m, 14.7 m and 0.7 %, respectively. The deep basin induces a monomictic pattern, with thermal stratification during the wet/warm season associated with anoxic bottom waters (1/3 of lake volume), and mixing during dry and cool season. Based on in situ measurements of tributary river discharges, theoretical retention time (RT) has been estimated in 13.4 years. The morphometry of Lake Nova promote long water RT and the warm monomictic mixing pattern, which is in accordance to the deep tropical lakes in Brazil.

  7. Characterization of Lake Michigan coastal lakes using zooplankton assemblages

    USGS Publications Warehouse

    Whitman, Richard L.; Nevers, Meredith B.; Goodrich, Maria L.; Murphy, Paul C.; Davis, Bruce M.

    2004-01-01

    Zooplankton assemblages and water quality were examined bi-weekly from 17 April to 19 October 1998 in 11 northeastern Lake Michigan coastal lakes of similar origin but varied in trophic status and limnological condition. All lakes were within or adjacent to Sleeping Bear Dunes National Lakeshore, Michigan. Zooplankton (principally microcrustaceans and rotifers) from triplicate Wisconsin net (80 I?m) vertical tows taken at each lake's deepest location were analyzed. Oxygen-temperature-pH-specific conductivity profiles and surface water quality were concurrently measured. Bray-Curtis similarity analysis showed small variations among sample replicates but large temporal differences. The potential use of zooplankton communities for environmental lake comparisons was evaluated by means of BIOENV (Primer 5.1) and principal component analyses. Zooplankton analyzed at the lowest identified taxonomic level yielded greatest sensitivity to limnological variation. Taxonomic and ecological aggregations of zooplankton data performed comparably, but less well than the finest taxonomic analysis. Secchi depth, chlorophyll a, and sulfate concentrations combined to give the best correlation with patterns of variation in the zooplankton data set. Principal component analysis of these variables revealed trophic status as the most influential major limnological gradient among the study lakes. Overall, zooplankton abundance was an excellent indicator of variation in trophic status.

  8. Lake Tahoe

    EPA Pesticide Factsheets

    Information on the Lake Tahoe watershed, EPA's protection efforts, water quality issues, effects of climate change, Lake Tahoe Total Maximum Daily Load (TMDL), EPA-sponsored projects, list of partner agencies.

  9. Seroprevalence of hepatitis E virus in domestic pigs and wild boars in Switzerland.

    PubMed

    Burri, C; Vial, F; Ryser-Degiorgis, M-P; Schwermer, H; Darling, K; Reist, M; Wu, N; Beerli, O; Schöning, J; Cavassini, M; Waldvogel, A

    2014-12-01

    Hepatitis E is considered an emerging human viral disease in industrialized countries. Studies from Switzerland report a human seroprevalence of hepatitis E virus (HEV) of 2.6-21%, a range lower than in adjacent European countries. The aim of this study was to determine whether HEV seroprevalence in domestic pigs and wild boars is also lower in Switzerland and whether it is increasing and thus indicating that this zoonotic viral infection is emerging. Serum samples collected from 2,001 pigs in 2006 and 2011 and from 303 wild boars from 2008 to 2012 were analysed by ELISA for the presence of HEV-specific antibodies. Overall HEV seroprevalence was 58.1% in domestic pigs and 12.5% in wild boars. Prevalence in domestic pigs was significantly higher in 2006 than in 2011. In conclusion, HEV seroprevalence in domestic pigs and wild boars in Switzerland is comparable with the seroprevalence in other countries and not increasing. Therefore, prevalence of HEV in humans must be related to other factors than prevalence in pigs or wild boars. © 2014 Blackwell Verlag GmbH.

  10. [Choice of Hospital for Childbirth in Switzerland: Decision Factors and Sources of Information].

    PubMed

    Wiedenhöfer, D; Keppler, S

    2017-06-01

    The introduction of Swiss DRG in 2012 offers women in Switzerland free choice of hospital. The objective of this study was to identify decision factors affecting the choice of hospital birth in Switzerland and to rate the degree of utilization of information sources. In seven Swiss hospitals, located in the German-speaking part of Switzerland, women in childbed were interviewed in writing. When choosing a hospital, factors rated by women as important were professional competence, good medical care, good obstetric competence, good nursing care and a neat and clean atmosphere. Important sources of information are recommendations of friends, own experience gained during previous hospital stays, the specialist, family, and the hospital homepage. Information meetings for pregnant women are essential for hospitals because they encourage women's decision to use the hospital. Web presence of the hospital and a good relationship with the specialists or family doctors are important, but experience of friends, family or one's own experience with stay at the hospital play a more important role. © Georg Thieme Verlag KG Stuttgart · New York.

  11. Geographical distributions of lake trout strains stocked in Lake Ontario

    USGS Publications Warehouse

    Elrod, Joseph H.; O'Gorman, Robert; Schneider, Clifford P.; Schaner, Ted

    1996-01-01

    Geographical distributions of lake trout (Salvelinus namaycush) stocked at seven locations in U.S. waters and at four locations in Canadian waters of Lake Ontario were determined from fish caught with gill nets in September in 17 areas of U.S. waters and at 10 fixed locations in Canadian waters in 1986-95. For fish of a given strain stocked at a given location, geographical distributions were not different for immature males and immature females or for mature males and mature females. The proportion of total catch at the three locations nearest the stocking location was higher for mature fish than for immature fish in all 24 available comparisons (sexes combined) and was greater for fish stocked as yearlings than for those stocked as fingerlings in all eight comparisons. Mature fish were relatively widely dispersed from stocking locations indicating that their tendency to return to stocking locations for spawning was weak, and there was no appreciable difference in this tendency among strains. Mature lake trout were uniformly distributed among sampling locations, and the strain composition at stocking locations generally reflected the stocking history 5 to 6 years earlier. Few lake trout moved across Lake Ontario between the north and south shores or between the eastern outlet basin and the main lake basin. Limited dispersal from stocking sites supports the concept of stocking different genetic strains in various parts of the lake with the attributes of each strain selected to match environmental conditions in the portion of the lake where it is stocked.

  12. Deglaciation, lake levels, and meltwater discharge in the Lake Michigan basin

    USGS Publications Warehouse

    Colman, Steven M.; Clark, J.A.; Clayton, L.; Hansel, A.K.; Larsen, C.E.

    1994-01-01

    The deglacial history of the Lake Michigan basin, including discharge and routing of meltwater, is complex because of the interaction among (1) glacial retreats and re-advances in the basin (2) the timing of occupation and the isostatic adjustment of lake outlets and (3) the depositional and erosional processes that left evidence of past lake levels. In the southern part of the basin, a restricted area little affected by differential isostasy, new studies of onshore and offshore areas allow refinement of a lake-level history that has evolved over 100 years. Important new data include the recognition of two periods of influx of meltwater from Lake Agassiz into the basin and details of the highstands gleaned from sedimentological evidence. Major disagreements still persist concerning the exact timing and lake-level changes associated with the Algonquin phase, approximately 11,000 BP. A wide variety of independent data suggests that the Lake Michigan Lobe was thin, unstable, and subject to rapid advances and retreats. Consequently, lake-level changes were commonly abrupt and stable shorelines were short-lived. The long-held beliefs that the southern part of the basin was stable and separated from deformed northern areas by a hinge-line discontinuity are becoming difficult to maintain. Numerical modeling of the ice-earth system and empirical modeling of shoreline deformation are both consistent with observed shoreline tilting in the north and with the amount and pattern of modern deformation shown by lake-level gauges. New studies of subaerial lacustrine features suggest the presence of deformed shorelines higher than those originally ascribed to the supposed horizontal Glenwood level. Finally, the Lake Michigan region as a whole appears to behave in a similar manner to other areas, both local (other Great Lakes) and regional (U.S. east coast), that have experienced major isostatic changes. Detailed sedimentological and dating studies of field sites and additional

  13. 77 FR 39638 - Safety Zone; Barbara Harder Wedding Fireworks, Lake Erie, Lake View, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-05

    ...-AA00 Safety Zone; Barbara Harder Wedding Fireworks, Lake Erie, Lake View, NY AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing a temporary safety zone on Lake Erie, Lake View, NY. This safety zone is intended to restrict vessels from a portion of Lake Erie...

  14. Genetic diversity of lake whitefish in lakes Michigan and Huron: sampling, standardization, and research priorities

    USGS Publications Warehouse

    Stott, Wendylee; VanDeHey, Justin A.; Sloss, Brian L.

    2010-01-01

    We combined data from two laboratories to increase the spatial extent of a genetic data set for lake whitefish Coregonus clupeaformis from lakes Huron and Michigan and saw that genetic diversity was greatest between lakes, but that there was also structuring within lakes. Low diversity among stocks may be a reflection of relatively recent colonization of the Great Lakes, but other factors such as recent population fluctuation and localized stresses such as lamprey predation or heavy exploitation may also have a homogenizing effect. Our data suggested that there is asymmetrical movement of lake whitefish between Lake Huron and Lake Michigan; more genotypes associated with Lake Michigan were observed in Lake Huron. Adding additional collections to the calibrated set will allow further examination of diversity in other Great Lakes, answer questions regarding movement among lakes, and estimate contributions of stocks to commercial yields. As the picture of genetic diversity and population structure of lake whitefish in the Great Lakes region emerges, we need to develop methods to combine data types to help identify important areas for biodiversity and thus conservation. Adding genetic data to existing models will increase the precision of predictions of the impacts of new stresses and changes in existing pressures on an ecologically and commercially important species.

  15. [Characterizing chromophoric dissolved organic matter (CDOM) in Lake Honghu, Lake Donghu and Lake Liangzihu using excitation-emission matrices (EEMs) fluorescence and parallel factor analysis (PARAFAC)].

    PubMed

    Zhou, Yong-Qiang; Zhang, Yun-Lin; Niu, Cheng; Wang, Ming-Zhu

    2013-12-01

    Little is known about DOM characteristics in medium to large sized lakes located in the middle and lower reaches of Yangtze River, like Lake Honghu, Lake Donghu and Lake Liangzihu. Absorption, fluorescence and composition characteristics of chromophoric dissolved organic matter (CDOM) are presented using the absorption spectroscopy, the excitation-emission ma trices (EEMs) fluorescence and parallel factor analysis (PARAFAC) model based on the data collected in Sep-Oct. 2007 including 15, 9 and 10 samplings in Lake Honghu, Lake Donghu and Lake Liangzihu, respectively. CDOM absorption coefficient at 350 nm a(350) coefficient in Lake Honghu was significantly higher than those in Lake Donghu and Lake Liangzihu (t-test, p< 0. 001). A significant negative correlation was found between CDOM spectral slope in the wavelength range of 280-500 nm (S280-500) and a(350) (R2 =0. 781, p<0. 001). The mean value of S280-500 in Lake Honghu was significantly lower than those in Lake Donghu (t-test, pLake Liangzihu (t-test, p<0. 001). The mean value of spectral slope ratio SR in Lake Honghu was also significantly lower than those in Lake Donghu and Lake Liangzihu (t-test, p<0. 05). Two humic-like (C1, C2) and two protein-like fluorescent components (C3, C4) were identified by PARAFAC model, among which significant positive correlations were found between C1 and C2 (R2 =0. 884, p<0. 001), C3 and C4 (R2 =0. 677, p<0.001), respectively, suggesting that the sources of the two humic-like components as well as the two protein-like components were similar. However, no significant correlation has been found between those 4 fluorescent components and DOC concentration. Th e fluorescenceindices of FI255 (HIX), Fl265, FI310 (BIX) and Fl370 in Lake Donghu were all significantly higher than those in Lake Liangzihu (t-test, p <0.05) and Lake Honghu (t-test, p<0. 01), indicating that the eutrophication status in Lake Donghu was higher than Lake Honghu and Lake Liangzihu.

  16. Exploring trends, causes, and consequences of declining lipids in Lake Superior lake trout

    EPA Science Inventory

    The ability of lake trout to forage in deepwater habitats is facilitated by high lipid content, which affords buoyancy. In Lake Superior, lean lake trout historically occupied depths < 80 m, and siscowet lake trout occupied depths > 80 m. Siscowets have been known f...

  17. Great Lakes

    USGS Publications Warehouse

    Edsall, Thomas A.; Mac, Michael J.; Opler, Paul A.; Puckett Haecker, Catherine E.; Doran, Peter D.

    1998-01-01

    The Great Lakes region, as defined here, includes the Great Lakes and their drainage basins in Minnesota, Wisconsin, Illinois, Indiana, Ohio, Pennsylvania, and New York. The region also includes the portions of Minnesota, Wisconsin, and the 21 northernmost counties of Illinois that lie in the Mississippi River drainage basin, outside the floodplain of the river. The region spans about 9º of latitude and 20º of longitude and lies roughly halfway between the equator and the North Pole in a lowland corridor that extends from the Gulf of Mexico to the Arctic Ocean.The Great Lakes are the most prominent natural feature of the region (Fig. 1). They have a combined surface area of about 245,000 square kilometers and are among the largest, deepest lakes in the world. They are the largest single aggregation of fresh water on the planet (excluding the polar ice caps) and are the only glacial feature on Earth visible from the surface of the moon (The Nature Conservancy 1994a).The Great Lakes moderate the region’s climate, which presently ranges from subarctic in the north to humid continental warm in the south (Fig. 2), reflecting the movement of major weather masses from the north and south (U.S. Department of the Interior 1970; Eichenlaub 1979). The lakes act as heat sinks in summer and heat sources in winter and are major reservoirs that help humidify much of the region. They also create local precipitation belts in areas where air masses are pushed across the lakes by prevailing winds, pick up moisture from the lake surface, and then drop that moisture over land on the other side of the lake. The mean annual frost-free period—a general measure of the growing-season length for plants and some cold-blooded animals—varies from 60 days at higher elevations in the north to 160 days in lakeshore areas in the south. The climate influences the general distribution of wild plants and animals in the region and also influences the activities and distribution of the human

  18. Lakes, Lagerstaetten, and Evolution

    NASA Astrophysics Data System (ADS)

    Kordesch, E. G.; Park, L. E.

    2001-12-01

    The diversity of terrestrial systems is estimated to be greater than in the marine realm. However no hard data yet exists to substantiate this claim. Ancient lacustrine deposits may preserve an exceptionally diverse fossil fauna and aid in determining continental faunal diversities. Fossils preserved in lake deposits, especially those with exceptional preservation (i.e. Konservat Lagerstaetten), may represent a dependable method for determining species diversity changes in the terrestrial environment because of their faunal completeness. Important Konservat Lagerstaetten, such as the Green River Formation (US) and Messel (Germany), both Eocene in age, are found in lake sediments and show a remarkable faunal diversity for both vertebrates and invertebrates. To date information from nearly 25 lake lagerstaetten derived from different types of lake basins from the Carboniferous to the Miocene have been collected and described. Carboniferous sites derive from the cyclothems of Midcontinent of the US while many Cenozoic sites have been described from North and South America as well as Europe and Australia. Asian sites contain fossils from the Mesozoic and Cenozoic. With this data, insight into the evolutionary processes associated with lake systems can be examined. Do lakes act as unique evolutionary crucibles in contrast to marine systems? The speciation of cichlid fishes in present-day African lakes appears to be very high and is attributed to the diversity of environments found in large rift lakes. Is this true of all ancient lakes or just large rift lakes? The longevity of a lake system may be an important factor in allowing speciation and evolutionary processes to occur; marine systems are limited only in the existence of environments as controlled by tectonics and sea level changes, on the order of tens of millions of years. Rift lakes are normally the longest lived in the millions of years. Perhaps there are only certain types of lakes in which speciation of

  19. Suspended-sediment budget, flow distribution, and lake circulation for the Fox Chain of Lakes in Lake and McHenry Counties, Illinois, 1997-99

    USGS Publications Warehouse

    Schrader, David L.; Holmes, Robert R.

    2000-01-01

    The Fox Chain of Lakes is a glacial lake system in McHenry and Lake Counties in northern Illinois and southern Wisconsin. Sedimentation and nutrient overloading have occurred in the lake system since the first dam was built (1907) in McHenry to raise water levels in the lake system. Using data collected from December 1, 1997, to June 1, 1999, suspended-sediment budgets were constructed for the most upstream lake in the system, Grass Lake, and for the lakes downstream from Grass Lake. A total of 64,900 tons of suspended sediment entered Grass Lake during the study, whereas a total of 70,600 tons of suspended sediment exited the lake, indicating a net scour of 5,700 tons of sediment. A total of 44,100 tons of suspended sediment was measured exiting the Fox Chain of Lakes at Johnsburg, whereas 85,600 tons entered the system downstream from Grass Lake. These suspended-sediment loads indicate a net deposition of 41,500 tons downstream from Grass Lake, which represents a trapping efficiency of 48.5 percent. A large amount of recreational boating takes place on the Fox Chain of Lakes during summer months, and suspended-sediment load was observed to rise from 110 tons per day to 339 tons per day during the 1999 Memorial Day weekend (May 26 ?31, 1999). Presumably, this rise was the result of the boating traffic because no other hydrologic event is known to have occurred that might have caused the rise. This study covers a relatively short period and may not represent the long-term processes of the Fox Chain of Lakes system, although the sediment transport was probably higher than an average year. The bed sediments found on the bottom of the lakes are composed of mainly fine particles in the silt-clay range. The Grass Lake sediments were characterized as black peat with an organic content of between 9 and 18 percent, and the median particle size ranged from 0.000811 to 0.0013976 inches. Other bed material samples were collected at streamflow-gaging stations on the

  20. Changing abundance of Hexagenia mayfly nymphs in western Lake Erie of the Laurentian Great Lakes: Impediments to assessment of lake recovery?

    USGS Publications Warehouse

    Schloesser, D.W.; Nalepa, T.F.

    2001-01-01

    After an absence of 40 years, mayfly nymphs of the genus Hexagenia were found in sediments of western Lake Erie of the Laurentian Great Lakes in 1993 and, by 1997, were abundant enough to meet a mayfly-density management goal (ca. 350 nymphs m—2) based on pollution-abatement programs. We sampled nymphs in western Lake Erie and Lake St. Clair, located upstream of western Lake Erie, to determine the importance of seasonal abundance and life-history characteristics of nymphs (e.g., emergence and recruitment) on density estimates relative to the mayfly-density management goal. Two types of density patterns were observed: (1) densities were relatively high in spring and gradually decreased through late summer (observed in Lake Erie and Lake St. Clair in 1997 and Lake St. Clair in 1999) and (2) densities were relatively high in spring, gradually decreased to mid summer, abruptly decreased in mid summer, and then increased between summer and late fall (Lake Erie and Lake St. Clair in 1998 and Lake Erie in 1999). Length-frequency distributions of nymphs and observations of adults indicate that the primary cause for the two density patterns was attributed to failed (first pattern) and successful (second pattern) reproduction and emergence of nymphs into adults in mid summer. Gradual declines in densities were attributed to mortality of nymphs. Our results indicate that caution should be used when evaluating progress of pollution-abatement programs based on mayfly densities because recruitment success is variable both between and within years. Additionally, the interpretation of progress toward management goals, relative to the restoration of Hexagenia populations in the Great Lakes and possibly other water bodies throughout the world, is influenced by the number of years in which consequtive collections are made.

  1. 33 CFR 162.220 - Hoover Dam, Lake Mead, and Lake Mohave (Colorado River), Ariz.-Nev.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Hoover Dam, Lake Mead, and Lake... REGULATIONS § 162.220 Hoover Dam, Lake Mead, and Lake Mohave (Colorado River), Ariz.-Nev. (a) Lake Mead and... the axis of Hoover Dam and that portion of Lake Mohave (Colorado River) extending 4,500 feet...

  2. 33 CFR 162.220 - Hoover Dam, Lake Mead, and Lake Mohave (Colorado River), Ariz.-Nev.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Hoover Dam, Lake Mead, and Lake... REGULATIONS § 162.220 Hoover Dam, Lake Mead, and Lake Mohave (Colorado River), Ariz.-Nev. (a) Lake Mead and... the axis of Hoover Dam and that portion of Lake Mohave (Colorado River) extending 4,500 feet...

  3. 33 CFR 162.220 - Hoover Dam, Lake Mead, and Lake Mohave (Colorado River), Ariz.-Nev.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Hoover Dam, Lake Mead, and Lake... REGULATIONS § 162.220 Hoover Dam, Lake Mead, and Lake Mohave (Colorado River), Ariz.-Nev. (a) Lake Mead and... the axis of Hoover Dam and that portion of Lake Mohave (Colorado River) extending 4,500 feet...

  4. 33 CFR 162.220 - Hoover Dam, Lake Mead, and Lake Mohave (Colorado River), Ariz.-Nev.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Hoover Dam, Lake Mead, and Lake... REGULATIONS § 162.220 Hoover Dam, Lake Mead, and Lake Mohave (Colorado River), Ariz.-Nev. (a) Lake Mead and... the axis of Hoover Dam and that portion of Lake Mohave (Colorado River) extending 4,500 feet...

  5. Lake Characteristics Influencing Spawning Success of Muskellunge in Northern Wisconsin Lakes

    Treesearch

    Ashley J. Rust; James S. Diana; Terry L. Margenau; Clayton J. Edwards

    2002-01-01

    We determined the physical, chemical, biological, and land use characteristics that distinguish northern Wisconsin lakes with self-sustaining populations of muskellunge Esox masquinongy from lakes where stocking is required to maintain populations. Lakes that supported self-sustaining muskellunge populations were characterized by fewer shoreline...

  6. Regional differences in self-reported screening, prevalence and management of cardiovascular risk factors in Switzerland.

    PubMed

    Marques-Vidal, Pedro; Paccaud, Fred

    2012-03-28

    In Switzerland, health policies are decided at the local level, but little is known regarding their impact on the screening and management of cardiovascular risk factors (CVRFs). We thus aimed at assessing geographical levels of CVRFs in Switzerland. Swiss Health Survey for 2007 (N = 17,879). Seven administrative regions were defined: West (Leman), West-Central (Mittelland), Zurich, South (Ticino), North-West, East and Central Switzerland. Obesity, smoking, hypertension, dyslipidemia and diabetes prevalence, treatment and screening within the last 12 months were assessed by interview. After multivariate adjustment for age, gender, educational level, marital status and Swiss citizenship, no significant differences were found between regions regarding prevalence of obesity or current smoking. Similarly, no differences were found regarding hypertension screening and prevalence. Two thirds of subjects who had been told they had high blood pressure were treated, the lowest treatment rates being found in East Switzerland: odds-ratio and [95% confidence interval] 0.65 [0.50-0.85]. Screening for hypercholesterolemia was more frequently reported in French (Leman) and Italian (Ticino) speaking regions. Four out of ten participants who had been told they had high cholesterol levels were treated and the lowest treatment rates were found in German-speaking regions. Screening for diabetes was higher in Ticino (1.24 [1.09 - 1.42]). Six out of ten participants who had been told they had diabetes were treated, the lowest treatment rates were found for German-speaking regions. In Switzerland, cardiovascular risk factor screening and management differ between regions and these differences cannot be accounted for by differences in populations' characteristics. Management of most cardiovascular risk factors could be improved.

  7. Regional differences in self-reported screening, prevalence and management of cardiovascular risk factors in Switzerland

    PubMed Central

    2012-01-01

    Background In Switzerland, health policies are decided at the local level, but little is known regarding their impact on the screening and management of cardiovascular risk factors (CVRFs). We thus aimed at assessing geographical levels of CVRFs in Switzerland. Methods Swiss Health Survey for 2007 (N = 17,879). Seven administrative regions were defined: West (Leman), West-Central (Mittelland), Zurich, South (Ticino), North-West, East and Central Switzerland. Obesity, smoking, hypertension, dyslipidemia and diabetes prevalence, treatment and screening within the last 12 months were assessed by interview. Results After multivariate adjustment for age, gender, educational level, marital status and Swiss citizenship, no significant differences were found between regions regarding prevalence of obesity or current smoking. Similarly, no differences were found regarding hypertension screening and prevalence. Two thirds of subjects who had been told they had high blood pressure were treated, the lowest treatment rates being found in East Switzerland: odds-ratio and [95% confidence interval] 0.65 [0.50-0.85]. Screening for hypercholesterolemia was more frequently reported in French (Leman) and Italian (Ticino) speaking regions. Four out of ten participants who had been told they had high cholesterol levels were treated and the lowest treatment rates were found in German-speaking regions. Screening for diabetes was higher in Ticino (1.24 [1.09 - 1.42]). Six out of ten participants who had been told they had diabetes were treated, the lowest treatment rates were found for German-speaking regions. Conclusions In Switzerland, cardiovascular risk factor screening and management differ between regions and these differences cannot be accounted for by differences in populations' characteristics. Management of most cardiovascular risk factors could be improved. PMID:22452881

  8. Evaluating COSMO's lake module (FLake) for an East-African lake using a comprehensive set of lake temperature profiles

    NASA Astrophysics Data System (ADS)

    Thiery, W.; Martynov, A.; Darchambeau, F.; Demuzere, M.; van Lipzig, N.

    2012-04-01

    The African great lakes are of utmost importance for the local economy (fishing), as well as being essential to the survival of the local people. During last decades, these lakes have been changing rapidly and their evolution is a major concern. Hence, it is important to correctly represent them in regional climate models for simulations over tropical Africa. However, so far lake models have been developed and tested primarily for boreal conditions. In this study, for the first time the freshwater lake model FLake is evaluated over East-Africa, more specifically over lake Kivu. Meteorological observations from January 2003 to December 2008 from an automatic weather station in Bukavu, DRC, are used to drive the standalone version of FLake. For the evaluation, a unique dataset is used which contains over 200 temperature profiles recorded since 2002. Results show that FLake in its default configuration is very successful at reproducing both the timing and magnitude of the seasonal cycle at 5 m depth. Flake captures that this seasonality is regulated by the water vapour pressure, which constrains evaporation except during summer (JJA). A positive bias of ~1 K is attributed to the driving data, which are collected in the city and are therefore expected to mirror higher temperatures and lower wind speeds compared to the lake surface. The evaluation also showed that driving FLake with Era-Interim from the nearest pixel does only slightly deteriorate the model performance. Using forcing fields from the Canadian Regional Climate Model, version 5 (CRCM5) simulation output gives similar performance as Era-Interim. Furthermore, a drawback of FLake is that it does not account for salinity and its effect upon lake stratification, and therefore requires artificial initial conditions for both lake depth and bottom temperature in order to reproduce the correct mixing regime in lake Kivu. Further research will therefore aim at improving FLake's representation of tropical lakes.

  9. Seasonal thermal ecology of adult walleye (Sander vitreus) in Lake Huron and Lake Erie.

    PubMed

    Peat, Tyler B; Hayden, Todd A; Gutowsky, Lee F G; Vandergoot, Christopher S; Fielder, David G; Madenjian, Charles P; Murchie, Karen J; Dettmers, John M; Krueger, Charles C; Cooke, Steven J

    2015-10-01

    The purpose of this study was to characterize thermal patterns and generate occupancy models for adult walleye from lakes Erie and Huron with internally implanted biologgers coupled with a telemetry study to assess the effects of sex, fish size, diel periods, and lake. Sex, size, and diel periods had no effect on thermal occupancy of adult walleye in either lake. Thermal occupancy differed between lakes and seasons. Walleye from Lake Erie generally experienced higher temperatures throughout the spring and summer months than did walleye in Lake Huron, due to limnological differences between the lakes. Tagged walleye that remained in Saginaw Bay, Lake Huron (i.e., adjacent to the release location), as opposed to those migrating to the main basin of Lake Huron, experienced higher temperatures, and thus accumulated more thermal units (the amount of temperature units amassed over time) throughout the year. Walleye that migrated toward the southern end of Lake Huron occupied higher temperatures than those that moved toward the north. Consequently, walleye that emigrated from Saginaw Bay experienced thermal environments that were more favorable for growth as they spent more time within their thermal optimas than those that remained in Saginaw Bay. Results presented in this paper provide information on the thermal experience of wild fish in a large lake, and could be used to refine sex- and lake-specific bioenergetics models of walleye in the Great Lakes to enable the testing of ecological hypotheses. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Seasonal thermal ecology of adult walleye (Sander vitreus) in Lake Huron and Lake Erie

    USGS Publications Warehouse

    Peat, Tyler B; Hayden, Todd A.; Gutowsky, Lee F G; Vandergoot, Christopher S.; Fielder, David G.; Madenjian, Charles P.; Murchie, Karen J; Dettmers, John M.; Krueger, Charles C.; Cooke, Steven J.

    2015-01-01

    The purpose of this study was to characterize thermal patterns and generate occupancy models for adult walleye from lakes Erie and Huron with internally implanted biologgers coupled with a telemetry study to assess the effects of sex, fish size, diel periods, and lake. Sex, size, and diel periods had no effect on thermal occupancy of adult walleye in either lake. Thermal occupancy differed between lakes and seasons. Walleye from Lake Erie generally experienced higher temperatures throughout the spring and summer months than did walleye in Lake Huron, due to limnological differences between the lakes. Tagged walleye that remained in Saginaw Bay, Lake Huron (i.e., adjacent to the release location), as opposed to those migrating to the main basin of Lake Huron, experienced higher temperatures, and thus accumulated more thermal units (the amount of temperature units amassed over time) throughout the year. Walleye that migrated toward the southern end of Lake Huron occupied higher temperatures than those that moved toward the north. Consequently, walleye that emigrated from Saginaw Bay experienced thermal environments that were more favorable for growth as they spent more time within their thermal optimas than those that remained in Saginaw Bay. Results presented in this paper provide information on the thermal experience of wild fish in a large lake, and could be used to refine sex- and lake-specific bioenergetics models of walleye in the Great Lakes to enable the testing of ecological hypotheses.

  11. Hydrology of Indiana lakes

    USGS Publications Warehouse

    Perrey, Joseph Irving; Corbett, Don Melvin

    1956-01-01

    The stabilization of lake levels often requires the construction of outlet control structures. A detailed study of past lake-level elevations and other hydologic date is necessary to establish a level that can be maintained and to determine the means necessary for maintaining the established level. Detailed lake-level records for 28 lakes are included in the report, and records for over 100 other lakes data are available in the U.S. Geological Survey Office, Indianapolis, Ind. Evaporation data from the four Class A evaporation station of the U. S. Weather Bureau have been compiled in this report. A table showing the established legal lake level and related data is included.

  12. First evidence of successful natural reproduction by planted lake trout in Lake Huron

    USGS Publications Warehouse

    Nester, Robert T.; Poe, Thomas P.

    1984-01-01

    Twenty-two lake trout (Salvelinus namaycush) swim-up fry, 24-27 mm long, were captured with emergent fry traps and a tow net in northwestern Lake Huron on a small nearshore reef off Alpena, Michigan, between May 10 and June 1, 1982. These catches represent the first evidence of successful production of swim-up fry by planted, hatchery-reared lake trout in Lake Huron since the lake trout rehabilitation program began in 1973.

  13. Estimation of lake water - groundwater interactions in meromictic mining lakes by modelling isotope signatures of lake water.

    PubMed

    Seebach, Anne; Dietz, Severine; Lessmann, Dieter; Knoeller, Kay

    2008-03-01

    A method is presented to assess lake water-groundwater interactions by modelling isotope signatures of lake water using meteorological parameters and field data. The modelling of delta(18)O and deltaD variations offers information about the groundwater influx into a meromictic Lusatian mining lake. Therefore, a water balance model is combined with an isotope water balance model to estimate analogies between simulated and measured isotope signatures within the lake water body. The model is operated with different evaporation rates to predict delta(18)O and deltaD values in a lake that is only controlled by weather conditions with neither groundwater inflow nor outflow. Comparisons between modelled and measured isotope values show whether the lake is fed by the groundwater or not. Furthermore, our investigations show that an adaptation of the Craig and Gordon model [H. Craig, L.I. Gordon. Deuterium and oxygen-18 variations in the ocean and the marine atmosphere. In Stable Isotopes in Oceanographic Studies and Paleotemperature, Spoleto, E. Tongiorgi (Ed.), pp. 9-130, Consiglio Nazionale delle Ricerche, Laboratorio di Geologia Nucleare, Pisa (1965).] to specific conditions in temperate regions seems necessary.

  14. 75 FR 13232 - Safety Zone; Lake Mead Intake Construction, Lake Mead, Boulder City, NV

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-19

    ...-AA00 Safety Zone; Lake Mead Intake Construction, Lake Mead, Boulder City, NV AGENCY: Coast Guard, DHS... waters of Lake Mead in support of the construction project for Lake Mead's Intake 3. This safety zone is... for the placement of an Intake Pipe from Lake Mead throughout 2010. This safety zone is necessary to...

  15. 78 FR 17869 - Safety Zone; Desert Storm Shootout; Lake Havasu, Lake Havasu City, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-25

    ...-AA00 Safety Zone; Desert Storm Shootout; Lake Havasu, Lake Havasu City, AZ AGENCY: Coast Guard, DHS... navigable waters of the Colorado River in Lake Havasu, Lake Havasu City, Arizona in support of the Desert... Coast Guard to establish safety zones (33 U.S.C 1221 et seq.). Lake Racer LLC is sponsoring the Desert...

  16. Bioturbation enhances the aerobic respiration of lake sediments in warming lakes.

    PubMed

    Baranov, Viktor; Lewandowski, Jörg; Krause, Stefan

    2016-08-01

    While lakes occupy less than 2% of the total surface of the Earth, they play a substantial role in global biogeochemical cycles. For instance, shallow lakes are important sites of carbon metabolism. Aerobic respiration is one of the important drivers of the carbon metabolism in lakes. In this context, bioturbation impacts of benthic animals (biological reworking of sediment matrix and ventilation of the sediment) on sediment aerobic respiration have previously been underestimated. Biological activity is likely to change over the course of a year due to seasonal changes of water temperatures. This study uses microcosm experiments to investigate how the impact of bioturbation (by Diptera, Chironomidae larvae) on lake sediment respiration changes when temperatures increase. While at 5°C, respiration in sediments with and without chironomids did not differ, at 30°C sediment respiration in microcosms with 2000 chironomids per m(2) was 4.9 times higher than in uninhabited sediments. Our results indicate that lake water temperature increases could significantly enhance lake sediment respiration, which allows us to better understand seasonal changes in lake respiration and carbon metabolism as well as the potential impacts of global warming. © 2016 The Authors.

  17. Bioturbation enhances the aerobic respiration of lake sediments in warming lakes

    PubMed Central

    Krause, Stefan

    2016-01-01

    While lakes occupy less than 2% of the total surface of the Earth, they play a substantial role in global biogeochemical cycles. For instance, shallow lakes are important sites of carbon metabolism. Aerobic respiration is one of the important drivers of the carbon metabolism in lakes. In this context, bioturbation impacts of benthic animals (biological reworking of sediment matrix and ventilation of the sediment) on sediment aerobic respiration have previously been underestimated. Biological activity is likely to change over the course of a year due to seasonal changes of water temperatures. This study uses microcosm experiments to investigate how the impact of bioturbation (by Diptera, Chironomidae larvae) on lake sediment respiration changes when temperatures increase. While at 5°C, respiration in sediments with and without chironomids did not differ, at 30°C sediment respiration in microcosms with 2000 chironomids per m2 was 4.9 times higher than in uninhabited sediments. Our results indicate that lake water temperature increases could significantly enhance lake sediment respiration, which allows us to better understand seasonal changes in lake respiration and carbon metabolism as well as the potential impacts of global warming. PMID:27484649

  18. Lake Sturgeon, Acipenser fulvescens, movements in Rainy Lake, Minnesota and Ontario

    USGS Publications Warehouse

    Adams, W.E.; Kallemeyn, L.W.; Willis, D.W.

    2006-01-01

    Rainy Lake, Minnesota-Ontario, contains a native population of Lake Sturgeon (Acipenser fulvescens) that has gone largely unstudied. The objective of this descriptive study was to summarize generalized Lake Sturgeon movement patterns through the use of biotelemetry. Telemetry data reinforced the high utilization of the Squirrel Falls geographic location by Lake Sturgeon, with 37% of the re-locations occurring in that area. Other spring aggregations occurred in areas associated with Kettle Falls, the Pipestone River, and the Rat River, which could indicate spawning activity. Movement of Lake Sturgeon between the Seine River and the South Arm of Rainy Lake indicates the likelihood of one integrated population on the east end of the South Arm. The lack of re-locations in the Seine River during the months of September and October may have been due to Lake Sturgeon moving into deeper water areas of the Seine River and out of the range of radio telemetry gear or simply moving back into the South Arm. Due to the movements between Minnesota and Ontario, coordination of management efforts among provincial, state, and federal agencies will be important.

  19. Complete genome sequence of "Thiodictyon syntrophicum" sp. nov. strain Cad16T, a photolithoautotrophic purple sulfur bacterium isolated from the alpine meromictic Lake Cadagno.

    PubMed

    Luedin, Samuel M; Pothier, Joël F; Danza, Francesco; Storelli, Nicola; Frigaard, Niels-Ulrik; Wittwer, Matthias; Tonolla, Mauro

    2018-01-01

    " Thiodictyon syntrophicum" sp. nov. strain Cad16 T is a photoautotrophic purple sulfur bacterium belonging to the family of Chromatiaceae in the class of Gammaproteobacteria . The type strain Cad16 T was isolated from the chemocline of the alpine meromictic Lake Cadagno in Switzerland. Strain Cad16 T represents a key species within this sulfur-driven bacterial ecosystem with respect to carbon fixation. The 7.74-Mbp genome of strain Cad16 T has been sequenced and annotated. It encodes 6237 predicted protein sequences and 59 RNA sequences. Phylogenetic comparison based on 16S rRNA revealed that Thiodictyon elegans strain DSM 232 T the most closely related species. Genes involved in sulfur oxidation, central carbon metabolism and transmembrane transport were found. Noteworthy, clusters of genes encoding the photosynthetic machinery and pigment biosynthesis are found on the 0.48 Mb plasmid pTs485. We provide a detailed insight into the Cad16 T genome and analyze it in the context of the microbial ecosystem of Lake Cadagno.

  20. Stratigraphic framework and lake level history of Lake Kivu, East African Rift

    NASA Astrophysics Data System (ADS)

    Wood, Douglas A.; Scholz, Christopher A.

    2017-10-01

    Sediment cores and seismic reflection data acquired from the eastern basin of Lake Kivu, Rwanda reveal extensive limnologic variations due to changes in regional climate and basin structure. The eastern basin of the lake contains a sedimentary wedge which is > 1.5 km in thickness on its western side, and basal sediments are estimated to be at least 1.5 million years old. Sediments are likely to be thicker and older than this in the northern, Congolese basin of the lake. Above the ∼300 m iosbath only a thin layer of Holocene sediments are observed indication that this may have been the lake's high stand prior to that time. There are at least three erosional unconformities interpreted as desiccation or near-desiccation events which are estimated to have occurred at ∼475 ka, ∼100 ka, and ∼20 ka; the two most recent of these low stages likely developed during the African Megadrought and Last Glacial Maximum (LGM) periods. Following the LGM, the water levels rose to form a ∼100 m deep lake with its surface ∼370 m below the current lake level. The lake remained near that level for several thousand years and during this time the Virunga Volcanic Province expanded. At ∼12.2 ka a change to wetter climate conditions rapidly filled the lake to spill out of the Bukavu Bay basin southward toward Lake Tanganyika. Tephra sampled from the cores show that there have been at least 24 large local volcanic events since the early Holocene lake transgression.

  1. Hydrology of Crater, East and Davis Lakes, Oregon; with section on Chemistry of the Lakes

    USGS Publications Warehouse

    Phillips, Kenneth N.; Van Denburgh, A.S.

    1968-01-01

    Crater, East, and Davis Lakes are small bodies of fresh water that occupy topographically closed basins in Holocene volcanic terrane. Because the annual water supply exceeds annual evaporation, water must be lost by seepage from each lake. The seepage rates vary widely both in volume and in percentage of the total water supply. Crater Lake loses about 89 cfs (cubic feet per second), equivalent to about 72 percent of its average annual supply. East Lake loses about 2.3 cfs, or about 44 percent of its estimated supply. Davis Lake seepage varies greatly with lake level, but the average loss is about 150 cfs, more than 90 percent of its total supply. The destination of the seepage loss is not definitely known for any of the lakes. An approximate water budget was computed for stationary level for each lake, by using estimates 'by the writer to supplement the hydrologic data available. The three lake waters are dilute. Crater Lake contains about 80 ppm, (parts per million) of dissolved solids---mostly silica, sodium, and bicarbonate, and lesser amounts of calcium, sulfate, and chloride. Much of the dissolved-solids content of Crater Lake---especially the sulfate and chloride---may be related to fumarole and thermal-spring activity that presumably followed the collapse of Mount Mazama. Although Grater Lake loses an estimated 7,000 tons of its 1.5million-ton salt content each year by leakage, the chemical character of the lake did not change appreciably between 1912 and 1964. East Lake contains 200 ppm of dissolved solids, which includes major proportions of calcium, sodium, bicarbonate, and sulfate, but almost no chloride. The lake apparently receives much of its dissolved solids from subsurface thermal springs. Annual solute loss from East Lake by leakage is about 450 tons, or 3 percent of the lake's 15,000-ton estimated solute content. Davis Lake contains only 48 ppm of dissolved solids, much of which is silica and bicarbonate; chloride is almost completely absent

  2. 76 FR 2579 - Safety Zone; Lake Mead Intake Construction, Lake Mead, Boulder City, NV

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-14

    ...-AA00 Safety Zone; Lake Mead Intake Construction, Lake Mead, Boulder City, NV AGENCY: Coast Guard, DHS... waters of Lake Mead in support of the construction project for Lake Mead's Intake 3 during the first 6... blasting operations for the placement of a water intake pipe in Lake Mead during the first 6 months of 2011...

  3. Evaluation of methods to estimate lake herring spawner abundance in Lake Superior

    USGS Publications Warehouse

    Yule, D.L.; Stockwell, J.D.; Cholwek, G.A.; Evrard, L.M.; Schram, S.; Seider, M.; Symbal, M.

    2006-01-01

    Historically, commercial fishers harvested Lake Superior lake herring Coregonus artedi for their flesh, but recently operators have targeted lake herring for roe. Because no surveys have estimated spawning female abundance, direct estimates of fishing mortality are lacking. The primary objective of this study was to determine the feasibility of using acoustic techniques in combination with midwater trawling to estimate spawning female lake herring densities in a Lake Superior statistical grid (i.e., a 10′ latitude × 10′ longitude area over which annual commercial harvest statistics are compiled). Midwater trawling showed that mature female lake herring were largely pelagic during the night in late November, accounting for 94.5% of all fish caught exceeding 250 mm total length. When calculating acoustic estimates of mature female lake herring, we excluded backscattering from smaller pelagic fishes like immature lake herring and rainbow smelt Osmerus mordax by applying an empirically derived threshold of −35.6 dB. We estimated the average density of mature females in statistical grid 1409 at 13.3 fish/ha and the total number of spawning females at 227,600 (95% confidence interval = 172,500–282,700). Using information on mature female densities, size structure, and fecundity, we estimate that females deposited 3.027 billion (109) eggs in grid 1409 (95% confidence interval = 2.356–3.778 billion). The relative estimation error of the mature female density estimate derived using a geostatistical model—based approach was low (12.3%), suggesting that the employed method was robust. Fishing mortality rates of all mature females and their eggs were estimated at 2.3% and 3.8%, respectively. The techniques described for enumerating spawning female lake herring could be used to develop a more accurate stock–recruitment model for Lake Superior lake herring.

  4. Lake Chad, Chad, Africa

    NASA Image and Video Library

    1990-04-29

    Africa's Lake Chad where the borders of Chad, Niger, Nigeria and Cameroon merge (13.0N, 14.0E) has been undergoing change for the past 25 to 30 years when it was first noticed that the lake is drying up. Since then, astronauts have been photographing it on a regular basis to record the diminishing lake bed. This lake was once the aproximate size of Lake Erie but is now only about half that size and is still receeding.

  5. Beyond Watches and Chocolate-Global Mental Health Elective in Switzerland.

    PubMed

    Schneeberger, Andres R; Weiss, Andrea; von Blumenthal, Suzanne; Lang, Undine E; Huber, Christian G; Schwartz, Bruce J

    2016-08-01

    Despite increasing interest in global mental health training opportunities, only a few psychiatry residency programs offer global mental health training experiences in developing countries and even fewer programs offer it in other first-world countries. The authors developed a global mental health elective giving US psychiatry residents the opportunity to visit Switzerland to study and experience the mental health care system in this European country. This elective focuses on four major learning objectives: (1) the system of training and curriculum of postgraduate psychiatry education in Switzerland, (2) clinical and organizational aspects of Swiss mental health, (3) administrative aspects of Swiss mental health care delivery, and (4) scholarly activity. This program was uniquely tailored for psychiatry residents. The preliminary experiences with US psychiatry residents show that they value this learning experience, the opportunity to access a different mental health care system, as well as the potential to build international connections with peers.

  6. Large Rock-Slope Failures Impacting on Lakes - Event Reconstruction and Interaction Analysis in Two Alpine Regions Using Sedimentology and Geophysics

    NASA Astrophysics Data System (ADS)

    Knapp, S.; Anselmetti, F.; Gilli, A.; Krautblatter, M.; Hajdas, I.

    2016-12-01

    Massive rock-slope failures are responsible for more than 60% of all catastrophic landslides disasters. Lateglacial and Holocene rock-slope failures often occur as multistage failures, but we have only limited datasets to reconstruct detailed stages and still aim at improving our knowledge of mobility processes. In this context, studying lakes will become more and more important for two main reasons. On the one hand, the lake background sedimentation acts as a natural chronometer, which enables the stratigraphic positioning of events and helps to reconstruct the event history. This way we will be able to improve our knowledge on multistage massive rock-slope failures. On the other hand, climate warming forces us to face an increase of lakes forming due to glacial melting, leading to new hazardous landscape settings. We will be confronted with complex reaction chains and feedback loops related to rock-slope instability, stress adaptation, multistage rock-slope failures, lake tsunamis, entrainment of water and fines, and finally lubrication. As a result, in future we will have to deal more and more with failed rock material impacting on lakes with much longer runout-paths than expected, and which we have not been able to reconstruct in our models so far. Here we want to present the key findings of two of our studies on lake sediments related to large rock-slope failures: We used reflection seismic profiles and sediment cores for the reconstruction of the rockfall history in the landslide-dammed Lake Oeschinen in the Bernese Oberland, Switzerland, where we detected and dated ten events and correlated them to (pre)historical data. As a second project, we have been working on the mobility processes of the uppermost sediments deposited during the late event stadium of the Eibsee rock avalanche at Mount Zugspitze in the Bavarian Alps, Germany. In the reflection seismic profiles we detected sedimentary structures that show high levels of fluidization and thus would hint at

  7. Water-quality and lake-stage data for Wisconsin lakes, water year 2014

    USGS Publications Warehouse

    Manteufel, S. Bridgett; Robertson, Dale M.

    2017-05-25

    IntroductionThe U.S. Geological Survey (USGS), in cooperation with local and other agencies, collects data at selected lakes throughout Wisconsin. These data, accumulated over many years, provide a database for developing an improved understanding of the water quality of lakes. To make these data available to interested parties outside the USGS, the data are published annually in this report series. The locations of water-quality and lake-stage stations in Wisconsin for water year 2014 are shown in figure 1. A water year is the 12-month period from October 1 through September 30. It is designated by the calendar year in which it ends. Thus, the periodOctober 1, 2013, through September 30, 2014, is called “water year 2014.”The purpose of this report is to provide information about the chemical and physical characteristics of Wisconsin lakes. Data that have been collected at specific lakes, and information to aid in the interpretation of those data, are included in this report. Data collected include measurements of in-lake water quality and lake stage. Time series of Secchi depths, surface total phosphorus, and chlorophyll a concentrations collected during nonfrozen periods are included for many lakes. Graphs of vertical profiles of temperature, dissolved oxygen, pH, and specific conductance are included for sites where these parameters were measured. Descriptive information for each lake includes the location of the lake, area of the lake’s watershed, period for which data are available, revisions to previously published records, and pertinent remarks. Additional data, such as streamflow and water quality in tributary and outlet streams of some of the lakes, are published online at http://nwis.waterdata.usgs.gov/wi/nwis.Water-resources data, including stage and discharge data at most streamflow-gaging stations, are available online. The Wisconsin Water Science Center’s home page is at https://www.usgs.gov/centers/wisconsin-water-science-center. Information

  8. Helminths in an intensively stocked population of lake trout, Salvelinus namaycush, from Lake Huron

    USGS Publications Warehouse

    Muzzall, Patrick M.; Bowen, Charles A.

    2000-01-01

    Eighty stocked lake trout Salvelinus namaycush (Salmonidae), collected from 2 locations in Lake Huron in May 1995, were examined for parasites. The parasite fauna of this top predator in Lake Huron was characterized by only 6 helminth species. Echinorhynchus salmonis infected all lake trout with a mean intensity of 163.9. The intensity of this acanthocephalan species significantly increased with host length and weight. Eubothrium salvelini infected 78 lake trout with a maximum number of 81 scoleces counted. Diplostomum sp., Cyathocephalus truncatus, Capillaria salvelini, and Neoechinorhynchus sp. infrequently infected lake trout. The low parasite species richness in these lake trout is believed to be due to their large size at stocking and to the loss of historical enzootic host-parasite relationships that followed the absence of this fish species in Lake Huron for 26 yr.

  9. Glaciers, Glacial lakes and Glacial Lake Outburst Floods in the Koshi Basin

    NASA Astrophysics Data System (ADS)

    Shrestha, F.; Gao, X.; Khanal, N. R.; Maharjan, S. B.; Bajracharya, S. R.; Shrestha, R. B.; Lizong, W.; Mool, P. K.

    2016-12-01

    Glacier is a vital water resources for mountain communities. Recession in glacier area either increased the glacial lake size or develop a new lake. The consequences of these changes in lake has become one of the major issue in the management of GLOF risk. This paper presents the distribution of, and changes in, glaciers, glacial lakes in the Koshi basin and also looks at past GLOF events that have occurred in the basin and their distance of impact. Data on the number of glaciers and glacial lakes and their areas were generated for the years 1977, 1990, 2000, and 2010 using Landsat images. The study revealed that there were a total of 845 glaciers (Nepal side) and 2,168 glacial lakes (Nepal and China side) with a total area of 1,103 km2 and 127.608 km2 in 2010. The number of glacier increased by 15% (109) and area decreased by 26% (396 km2) over 33 years. In case of glacier lakes, the number and area increased from 1,160 to 2,168 and from 94.444 km2 to 127.608 km2 during 33 years with an overall growth rates of 86.9% and 35.1%. A large number of glacial lakes are small in size (≤ 0.1 km2). End moraine dammed lakes with area ≥ 0.1 km2 were selected to analyse the change characteristics of glacial lakes. The results show that there were 134 lakes ≥ 0.1 km2 in 2010; these lakes had a total area of 43.06 km2 in 1997, increased to 64.35 km2 in 2010. The distribution of lakes on the north side of the Himalayas (in China) was three times higher than on the south side of the Himalayas (in Nepal). Comparing the mean growth rate in area and length for the 33 years, the growth rate on the north side was found to be a little slower than that on the south side. This relationship did not hold true for length change in the different periods. The study identified 42 rapidly growing large lakes that are dangerous in terms of GLOF risk. In the past, 18 GLOF events have been reported. The downstream distance impacted by those events was up to 90 km. Among them, 13 GLOF events

  10. Spatial patterns of frequent floods in Switzerland

    NASA Astrophysics Data System (ADS)

    Schneeberger, Klaus; Rössler, Ole; Weingartner, Rolf

    2017-04-01

    Information about the spatial characteristics of high and extreme streamflow is often needed for an accurate analysis of flood risk and effective co-ordination of flood related activities, such as flood defence planning. In this study we analyse the spatial dependence of frequent floods in Switzerland across different scales. Firstly, we determine the average length of high and extreme flow events for 56 runoff time series of Swiss rivers. Secondly, a dependence measure expressing the probability that streamflow peaks are as high as peaks at a conditional site is used to describe and map the spatial extend of joint occurrence of frequent floods across Switzerland. Thirdly, we apply a cluster analysis to identify groups of sites that are likely to react similarly in terms of joint occurrence of high flow events. The results indicate that a time interval with a length of 3 days seems to be most appropriate to characterise the average length of high streamflow events across spatial scales. In the main Swiss basins, high and extreme streamflows were found to be asymptotically independent. In contrast, at the meso-scale distinct flood regions, which react similarly in terms of occurrence of frequent flood, were found. The knowledge about these regions can help to optimise flood defence planning or to estimate regional flood risk properly.

  11. Lake Michigan lake trout PCB model forecast post audit (oral presentation)

    EPA Science Inventory

    Scenario forecasts for total PCBs in Lake Michigan (LM) lake trout were conducted using the linked LM2-Toxics and LM Food Chain models, supported by a suite of additional LM models. Efforts were conducted under the Lake Michigan Mass Balance Study and the post audit represents an...

  12. Simulating Lake-Groundwater Interactions During Decadal Climate Cycles: Accounting For Variable Lake Area In The Watershed

    NASA Astrophysics Data System (ADS)

    Virdi, M. L.; Lee, T. M.

    2009-12-01

    The volume and extent of a lake within the topo-bathymetry of a watershed can change substantially during wetter and drier climate cycles, altering the interaction of the lake with the groundwater flow system. Lake Starr and other seepage lakes in the permeable sandhills of central Florida are vulnerable to climate changes as they rely exclusively on rainfall and groundwater for inflows in a setting where annual rainfall and recharge vary widely. The groundwater inflow typically arrives from a small catchment area bordering the lake. The sinkhole origin of these lakes combined with groundwater pumping from underlying aquifers further complicate groundwater interactions. Understanding the lake-groundwater interactions and their effects on lake stage over multi-decadal climate cycles is needed to manage groundwater pumping and public expectation about future lake levels. The interdependence between climate, recharge, changing lake area and the groundwater catchment pose unique challenges to simulating lake-groundwater interactions. During the 10-year study period, Lake Starr stage fluctuated more than 13 feet and the lake surface area receded and expanded from 96 acres to 148 acres over drier and wetter years that included hurricanes, two El Nino events and a La Nina event. The recently developed Unsaturated Zone Flow (UZF1) and Lake (LAK7) packages for MODFLOW-2005 were used to simulate the changing lake sizes and the extent of the groundwater catchment contributing flow to the lake. The lake area was discretized to occupy the largest surface area at the highest observed stage and then allowed to change size. Lake cells convert to land cells and receive infiltration as receding lake area exposes the underlying unsaturated zone to rainfall and recharge. The unique model conceptualization also made it possible to capture the dynamic size of the groundwater catchment contributing to lake inflows, as the surface area and volume of the lake changed during the study

  13. Lake Granbury and Lake Whitney Assessment Initiative Final Scientific/Technical Report Summary

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Harris, B. L.; Roelke, Daniel; Brooks, Bryan

    A team of Texas AgriLife Research, Baylor University and University of Texas at Arlington researchers studied the biology and ecology of Prymnesium parvum (golden algae) in Texas lakes using a three-fold approach that involved system-wide monitoring, experimentation at the microcosm and mesocosm scales, and mathematical modeling. The following are conclusions, to date, regarding this organism's ecology and potential strategies for mitigation of blooms by this organism. In-lake monitoring revealed that golden algae are present throughout the year, even in lakes where blooms do not occur. Compilation of our field monitoring data with data collected by Texas Parks and Wildlife andmore » Brazos River Authority (a period spanning a decade) revealed that inflow and salinity variables affect bloom formations. Thresholds for algae populations vary per lake, likely due to adaptations to local conditions, and also to variations in lake-basin morphometry, especially the presence of coves that may serve as hydraulic storage zones for P. parvum populations. More specifically, our in-lake monitoring showed that the highly toxic bloom that occurred in Lake Granbury in the winter of 2006/2007 was eliminated by increased river inflow events. The bloom was flushed from the system. The lower salinities that resulted contributed to golden algae not blooming in the following years. However, flushing is not an absolute requirement for bloom termination. Laboratory experiments have shown that growth of golden algae can occur at salinities ~1-2 psu but only when temperatures are also low. This helps to explain why blooms are possible during winter months in Texas lakes. Our in-lake experiments in Lake Whitney and Lake Waco, as well as our laboratory experiments, revealed that cyanobacteria, or some other bacteria capable of producing algicides, were able to prevent golden algae from blooming. Identification of this organism is a high priority as it may be a key to managing golden algae

  14. Water balance of a lake with floodplain buffering: Lake Tana, Blue Nile Basin, Ethiopia

    NASA Astrophysics Data System (ADS)

    Dessie, Mekete; Verhoest, Niko E. C.; Pauwels, Valentijn R. N.; Adgo, Enyew; Deckers, Jozef; Poesen, Jean; Nyssen, Jan

    2015-03-01

    Lakes are very important components of the earth's hydrological cycle, providing a variety of services for humans and ecosystem functioning. For a sustainable use of lakes, a substantial body of knowledge on their water balance is vital. We present here a detailed daily water balance analysis for Lake Tana, the largest lake in Ethiopia and the source of the Blue Nile. Rainfall on the lake is determined by Thiessen polygon procedure, open water evaporation is estimated by the Penman-combination equation and observed inflows for the gauged catchments as well as outflow data at the two lake outlets are directly used. Runoff from ungauged catchments is estimated using a simple rainfall-runoff model and runoff coefficients. Hillslope catchments and floodplains are treated separately, which makes this study unique compared to previous water balance studies. Impact of the floodplain on the lake water balance is analyzed by conducting scenario-based studies. We found an average yearly abstraction of 420 × 106 m3 or 6% of river inflows to the lake by the floodplain in 2012 and 2013. Nearly 60% of the inflow to the lake is from the Gilgel Abay River. Simulated lake levels compare well with the observed lake levels (R2 = 0.95) and the water balance can be closed with a closure error of 82 mm/year (3.5% of the total lake inflow). This study demonstrates the importance of floodplains and their influence on the water balance of the lake and the need of incorporating the effects of floodplains and water abstraction for irrigation to improve predictions.

  15. Morphological variation of siscowet lake trout in Lake Superior

    USGS Publications Warehouse

    Bronte, C.R.; Moore, S.A.

    2007-01-01

    Historically, Lake Superior has contained many morphologically distinct forms of the lake trout Salvelinus namaycush that have occupied specific depths and locations and spawned at specific times of the year. Today, as was probably the case historically, the siscowet morphotype is the most abundant. Recent interest in harvesting siscowets to extract oil containing omega-3 fatty acids will require additional knowledge of the biology and stock structure of these lightly exploited populations. The objective of this study was to determine whether shape differences exist among siscowet populations across Lake Superior and whether these shape differences can be used to infer stock structure. Morphometric analysis (truss protocol) was used to differentiate among siscowets sampled from 23 locations in Lake Superior. We analyzed 31 distance measurements among 14 anatomical landmarks taken from digital images of fish recorded in the field. Cluster analysis of size-corrected data separated fish into three geographic groups: The Isle Royale, eastern (Michigan), and western regions (Michigan). Finer scales of stock structure were also suggested. Discriminant function analysis demonstrated that head measurements contributed to most of the observed variation. Cross-validation classification rates indicated that 67–71% of individual fish were correctly classified to their region of capture. This is the first study to present shape differences associated with location within a lake trout morphotype in Lake Superior.

  16. Geophysical investigation of sentinel lakes in Lake, Seminole, Orange, and Volusia Counties, Florida

    USGS Publications Warehouse

    Reich, Christopher; Flocks, James; Davis, Jeffrey

    2012-01-01

    This study was initiated in cooperation with the St. Johns River Water Management District (SJRWMD) to investigate groundwater and surface-water interaction in designated sentinel lakes in central Florida. Sentinel lakes are a SJRWMD established set of priority water bodies (lakes) for which minimum flows and levels (MFLs) are determined. Understanding both the structure and lithology beneath these lakes can ultimately lead to a better understanding of the MFLs and why water levels fluctuate in certain lakes more so than in other lakes. These sentinel lakes have become important water bodies to use as water-fluctuation indicators in the SJRWMD Minimum Flows and Levels program and will be used to define long-term hydrologic and ecologic performance measures. Geologic control on lake hydrology remains poorly understood in this study area. Therefore, the U.S. Geological Survey investigated 16 of the 21 water bodies on the SJRWMD priority list. Geologic information was obtained by the tandem use of high-resolution seismic profiling (HRSP) and direct-current (DC) resistivity profiling to isolate both the geologic framework (structure) and composition (lithology). Previous HRSP surveys from various lakes in the study area have been successful in identifying karst features, such as subsidence sinkholes. However, by using this method only, it is difficult to image highly irregular or chaotic surfaces, such as collapse sinkholes. Resistivity profiling was used to complement HRSP by detecting porosity change within fractured or collapsed structures and increase the ability to fully characterize the subsurface. Lake Saunders (Lake County) is an example of a lake composed of a series of north-south-trending sinkholes that have joined to form one lake body. HRSP shows surface depressions and deformation in the substrate. Resistivity data likewise show areas in the southern part of the lake where resistivity shifts abruptly from approximately 400 ohm meters (ohm-m) along the

  17. Mercury accumulation in yellow perch in Wisconsin seepage lakes: Relation to lake characteristics

    USGS Publications Warehouse

    Cope, W.G.; Wiener, J.G.; Rada, R.G.

    1990-01-01

    We studied relations between lacustrine characteristics and the total mercury (Hg) content of calendar age-2 yellow perch (Perca flavescens) in 10 seepage lakes in north-central Wisconsin. Mean concentrations and burdens (masses) of Hg in whole perch varied widely among lakes, were negatively correlated with lake pH and were positively correlated with total Hg concentration in surficial profundal sediment. Approximately 80 to 90% of the variation in Hg concentration and burden in whole perch was explained with multiple regressions containing two independent variables: either lake pH or alkalinity, and Hg concentration in surficial sediment. Variation among lakes in the Hg concentration in yellow perch was unrelated to their relative rates of growth. The mean concentration of Hg in axial muscle tissue of age-5 walleyes (Stizostedion vitreum vitreum) from five of the study lakes was highly correlated with the mean concentration in whole age-2 perch in the same lakes. We hypothesized that the high Hg concentrations often seen in piscivorous fish in low-alkalinity lakes (relative to high-alkalinity lakes) is at least partly due to a greater dietary intake of Hg in such waters. Furthermore, the analysis of small yellow perch—the preferred prey of adult walleyes and an important forage species for many predatory fishes in the north-central United States—may be an effective approach to assessing Hg bioavailability in the region's lakes.

  18. Acceptance of Ambulatory Laparoscopic Cholecystectomy in Central Switzerland.

    PubMed

    Widjaja, Sandra P; Fischer, Henning; Brunner, Alexander R; Honigmann, Philipp; Metzger, Jürg

    2017-11-01

    Currently, most patients undergoing laparoscopic cholecystectomy (LC) in Switzerland are inpatients for 2-3 days. Due to a lack of available hospital beds, we asked whether day-case surgery would be an option for patients in central Switzerland. The questions of acceptability of outpatient LC and factors contributing to the acceptability thus arose. Hundred patients suffering from symptomatic cholecystolithiasis, capable of communicating in German, and between 18 and 65 years old, were included. Patients received a pre-operative questionnaire on medical history and social situation when informed consent on surgery and participation in the study was obtained. Exclusion criteria were patients suffering from acute cholecystitis or any type of cancer; having a BMI >40 kg/m 2 ; needing conversion to open cholecystectomy or an intraoperative drainage; and non-German speakers. Surgery was performed laparoscopically. Both surgeon and patient filled in a postoperative questionnaire. The surgeon's questionnaire listed medical and technical information, and the patients' questionnaire listed medical information, satisfaction with the treatment and willingness to be released on the same day. These data from both questionnaires were grouped into social and medical factors and analysed on their influence upon willingness to accept an ambulatory procedure. No outpatient follow-up apart from checking for readmission to our hospital within 1 month after discharge was performed. Of the 100 participants, one-third was male. More than two-thirds were Swiss citizens. Only one participant was ineligible for rapid release evaluation due to need of a drainage. Among the social factors contributing to the acceptability of ambulatory care, we found nationality to be relevant; Swiss citizens preferred an inpatient procedure, whereas non-Swiss citizens were significantly more willing to return home on the same day. Household size, sex and age did not correlate with a preference for

  19. Congenital syphilis in Switzerland: gone, forgotten, on the return.

    PubMed

    Meyer Sauteur, Patrick M; Trück, Johannes; Bosshard, Philipp P; Tomaske, Maren; Morán Cadenas, Francisca; Lautenschlager, Stephan; Goetschel, Philippe

    2012-01-11

    Acquired syphilis has re-emerged in many Western European countries. In contrast to international guidelines, screening for syphilis in pregnancy is not generally recommended in Switzerland. There has been an increase in the incidence of laboratory syphilis notifications in recent years, regardless of gender and age. We conducted a retrospective study, evaluating the total numbers of pregnant women with positive syphilis serology (Treponema pallidum Particle Agglutination assay, TPPA) from 2000 to 2009, and evaluated the clinical management and outcome of their offspring. In addition, we sought to determine cases of infectious syphilis (primary, secondary, and early latent syphilis) reported to the Swiss Federal Office of Public Health in women of childbearing age, which has previously been shown to precede changes in the incidence of congenital syphilis within a population. Out of 13,833 women who gave birth at our institution, positive syphilis serology was found in 9 pregnant women during the 10 years studied. A total of 6 pregnant women were diagnosed having syphilis infection during pregnancy. Regarding their offspring, 8 of the 9 newborns were tested serologically. One neonate experienced congenital syphilis because the adequately treated mother developed re-infection after treatment. Within the Swiss population, infectious syphilis cases in women of childbearing age increased substantially from 2006 to 2009. The epidemiologic data suggest that congenital syphilis could become a medical problem in Switzerland due to the rise of infectious syphilis cases in women of childbearing age that have been shown to be followed by changes in the congenital syphilis incidence. The persistence of congenital syphilis in Switzerland along with this rise of infectious syphilis in women of childbearing age suggests a potential for improvement of prenatal care and syphilis control programmes.

  20. Estimate of net trophic transfer efficiency of PCBs to Lake Michigan lake trout from their prey

    USGS Publications Warehouse

    Madenjian, Charles P.; Hesselberg, Robert J.; DeSorcie, Timothy J.; Schmidt, Larry J.; Stedman, Ralph M.; Quintal, Richard T.; Begnoche, Linda J.; Passino-Reader, Dora R.

    1998-01-01

    Most of the polychlorinated biphenyl (PCB) body burden accumulated by lake trout (Salvelinus namaycush) from the Laurentian Great Lakes is from their food. We used diet information, PCB determinations in both lake trout and their prey, and bioenergetics modeling to estimate the efficiency with which Lake Michigan lake trout retain PCBs from their food. Our estimates were the most reliable estimates to date because (a) the lake trout and prey fish sampled during our study were all from the same vicinity of the lake, (b) detailed measurements were made on the PCB concentrations of both lake trout and prey fish over wide ranges in fish size, and (c) lake trout diet was analyzed in detail over a wide range of lake trout size. Our estimates of net trophic transfer efficiency of PCBs to lake trout from their prey averaged from 0.73 to 0.89 for lake trout between the ages of 5 and 10 years old. There was no evidence of an upward or downward trend in our estimates of net trophic transfer efficiency for lake trout between the ages of 5 and 10 years old, and therefore this efficiency appeared to be constant over the duration of the lake trout's adult life in the lake. On the basis of our estimtes, lake trout retained 80% of the PCBs that are contained within their food.

  1. Great Lakes Literacy Principles

    NASA Astrophysics Data System (ADS)

    Fortner, Rosanne W.; Manzo, Lyndsey

    2011-03-01

    Lakes Superior, Huron, Michigan, Ontario, and Erie together form North America's Great Lakes, a region that contains 20% of the world's fresh surface water and is home to roughly one quarter of the U.S. population (Figure 1). Supporting a $4 billion sport fishing industry, plus $16 billion annually in boating, 1.5 million U.S. jobs, and $62 billion in annual wages directly, the Great Lakes form the backbone of a regional economy that is vital to the United States as a whole (see http://www.miseagrant.umich.edu/downloads/economy/11-708-Great-Lakes-Jobs.pdf). Yet the grandeur and importance of this freshwater resource are little understood, not only by people in the rest of the country but also by many in the region itself. To help address this lack of knowledge, the Centers for Ocean Sciences Education Excellence (COSEE) Great Lakes, supported by the U.S. National Science Foundation and the National Oceanic and Atmospheric Administration, developed literacy principles for the Great Lakes to serve as a guide for education of students and the public. These “Great Lakes Literacy Principles” represent an understanding of the Great Lakes' influences on society and society's influences on the Great Lakes.

  2. Climate-driven changes in grassland vegetation, snow cover, and lake water of the Qinghai Lake basin

    NASA Astrophysics Data System (ADS)

    Wang, Xuelu; Liang, Tiangang; Xie, Hongjie; Huang, Xiaodong; Lin, Huilong

    2016-07-01

    Qinghai Lake basin and the lake have undergone significant changes in recent decades. We examine MODIS-derived grassland vegetation and snow cover of the Qinghai Lake basin and their relations with climate parameters during 2001 to 2010. Results show: (1) temperature and precipitation of the Qinghai Lake basin increased while evaporation decreased; (2) most of the grassland areas improved due to increased temperature and growing season precipitation; (3) weak relations between snow cover and precipitation/vegetation; (4) a significantly negative correlation between lake area and temperature (r=-0.9, p<0.05) and (5) a positive relation between lake level (lake-level difference) and temperature (precipitation). Compared with Namco Lake (located in the inner Tibetan Plateau) where the primary water source of lake level increases was the accelerated melt of glacier/perennial snow cover in the lake basin, for the Qinghai Lake, however, it was the increased precipitation. Increased precipitation explained the improvement of vegetation cover in the Qinghai Lake basin, while accelerated melt of glacier/perennial snow cover was responsible for the degradation of vegetation cover in Namco Lake basin. These results suggest different responses to the similar warming climate: improved (degraded) ecological condition and productive capacity of the Qinghai Lake basin (Namco Lake basin).

  3. Lake whitefish and Diporeia spp. in the Great lakes: an overview

    USGS Publications Warehouse

    Nalepa, Thomas F.; Mohr, Lloyd C.; Henderson, Bryan A.; Madenjian, Charles P.; Schneeberger, Philip J.

    2005-01-01

    Because of growing concern in the Great Lakes over declines in abundance and growth of lake whitefish (Coregonus clupeaformis) and declines in abundance of the benthic amphipod Diporeia spp., a workshop was held to examine past and current trends, to explore trophic links, and to discuss the latest research results and needs. The workshop was divided into sessions on the status of populations in each of the lakes, bioenergetics and trophic dynamics, and exploitation and management. Abundance, growth, and condition of whitefish populations in Lakes Superior and Erie are stable and within the range of historical means, but these variables are declining in Lakes Michigan and Ontario and parts of Lake Huron. The loss of Diporeia spp., a major food item of whitefish, has been a factor in observed declines, particularly in Lake Ontario, but density-dependent factors also likely played a role in Lakes Michigan and Huron. The loss of Diporeia spp. is temporally linked to the introduction and proliferation of dreissenid mussels, but a direct cause for the negative response of Diporeia spp. has not been established. Given changes in whitefish populations, age-structured models need to be re-evaluated. Other whitefish research needs to include a better understanding of what environmental conditions lead to strong year-classes, improved aging techniques, and better information on individual population (stock) structure. Further collaborations between assessment biologists and researchers studying the lower food web would enhance an understanding of links between trophic levels.

  4. Lake trout (Salvelinus namaycush) populations in Lake Superior and their restoration in 1959-1993

    USGS Publications Warehouse

    Hansen, Michael J.; Peck, James W.; Schorfhaar, Richard G.; Selgeby, James H.; Schreiner, Donald R.; Schram, Stephen T.; Swanson, Bruce L.; MacCallum, Wayne R.; Burnham-Curtis, Mary K.; Curtis, Gary L.; Heinrich, John W.; Young, Robert J.

    1995-01-01

    Naturally-reproducing populations of lake trout (Salvelinus namaycush) have been reestablished in most of Lake Superior, but have not been restored to 1929-1943 average abundance. Progress toward lake trout restoration in Lake Superior is described, management actions are reviewed, and the effectiveness of those actions is evaluated; especially stocking lake trout as a tool for building spawning stocks, and subsequently, populations of wild recruits. Widespread destruction of lake trout stocks in the 1950s due to an intense fishery and sea lamprey (Petromyzon marinus) predation resulted in lower overall phenotypic diversity than was previously present. Stocking of yearling lake trout, begun in the 1950s, produced high densities of spawners that reproduced wherever inshore spawning habitat was widespread. Sea lampreys were greatly reduced, beginning in 1961, using selective chemical toxicants and barrier dams, but continue to exert substantial mortality. Fishery regulation was least effective in Wisconsin, where excessive gillnet effort caused high by-catch of lake trout until 1991, and in eastern Michigan, where lake trout restoration was deferred in favor of a tribal fishery for lake whitefish (Coregonus clupeaformis) in 1985. Restoration of stocks was quicker in offshore areas where remnant wild lake trout survived and fishing intensity was low, and was slower in inshore areas where stocked lake trout reproduced successfully and fishing intensity was high. Inshore stocks of wild lake trout are currently about 61 % of historic abundance in Michigan and 53% in Wisconsin. Direct comparison of modern and historic abundances of inshore lake trout stocks in Minnesota and Ontario is impossible due to lack of historic stock assessment data. Stocks in Minnesota are less abundant at present than in Michigan or Wisconsin, and stocks in Ontario are similar to those in Michigan. Further progress in stock recovery can only be achieved if sea lampreys are depressed and if

  5. Dysferlinopathy in Switzerland: clinical phenotypes and potential founder effects.

    PubMed

    Petersen, Jens A; Kuntzer, Thierry; Fischer, Dirk; von der Hagen, Maja; Huebner, Angela; Kana, Veronika; Lobrinus, Johannes A; Kress, Wolfram; Rushing, Elisabeth J; Sinnreich, Michael; Jung, Hans H

    2015-10-06

    Dysferlin is reduced in patients with limb girdle muscular dystrophy type 2B, Miyoshi myopathy, distal anterior compartment myopathy, and in certain Ethnic clusters. We evaluated clinical and genetic patient data from three different Swiss Neuromuscular Centers. Thirteen patients from 6 non-related families were included. Age of onset was 18.8 ± 4.3 years. In all patients, diallelic disease-causing mutations were identified in the DYSF gene. Nine patients from 3 non-related families from Central Switzerland carried the identical homozygous mutation, c.3031 + 2 T>C. A possible founder effect was confirmed by haplotype analysis. Three patients from two different families carried the heterozygous mutation, c.1064_1065delAA. Two novel mutations were identified (c.2869 C>T (p.Gln957Stop), c.5928 G>A (p.Trp1976Stop)). Our study confirms the phenotypic heterogeneity associated with DYSF mutations. Two mutations (c.3031 + 2 T>C, c.1064_1065delAA) appear common in Switzerland. Haplotype analysis performed on one case (c. 3031 + 2 T>C) suggested a possible founder effect.

  6. Imported human rabies in Switzerland, 2012: a diagnostic conundrum.

    PubMed

    Deubelbeiss, A N; Trachsel, Ch; Bachli, E B; Kuffer, A; Budka, H; Eniseyskiy, P; Zimmermann, H; Wallace, R M; Farley, S; Zanoni, R G

    2013-06-01

    Human rabies is rare in Western Europe. It is not easily recognized in the absence of a history of exposure. We describe the clinical course, diagnosis and follow-up of an imported human rabies case in Switzerland. The patient, a U.S. citizen, presented at an outpatient clinic in Iraq with pain in his right shoulder on July 5, 2012. On July 8 he was transferred to a hospital in the United Arab Emirates, where he exhibited progressive encephalitis with coma. On July 29, he was transferred to a hospital in Switzerland, where he died on July 31, 2012. The autopsy showed severe encephalitis. Rabies was diagnosed by the rapid fluorescent focus inhibition test (RFFIT) and confirmed by fluorescence antibody testing (FAT) in brain smears and immunohistochemistry on paraffin-embedded brain sections. The viral strain was characterized by RT-PCR followed by sequencing and phylogenetic analysis as an American bat rabies strain associated with Tadarida brasiliensis. Close contacts and exposed health care workers received postexposure prophylaxis (PEP). Copyright © 2013 Elsevier B.V. All rights reserved.

  7. How much dentists are ethically concerned about overtreatment; a vignette-based survey in Switzerland.

    PubMed

    Kazemian, Ali; Berg, Isabelle; Finkel, Christina; Yazdani, Shahram; Zeilhofer, Hans-Florian; Juergens, Philipp; Reiter-Theil, Stella

    2015-06-19

    Overtreatment (or unnecessary treatment) is when medical or dental services are provided with a higher volume or cost than is appropriate. This study aimed to investigate how a group of dentists in Switzerland, a wealthy country known to have high standards of healthcare including dentistry, evaluated the meaning of unnecessary treatments from an ethical perspective and, assessed the expected frequency of different possible behaviors among their peers. A vignette describing a situation that is susceptible for overtreatment of a patient was presented to a group of dentists. The vignette was followed by five options. A questionnaire including the vignette was posted to 2482 dentists in the German-speaking areas of Switzerland. The respondents were asked to rate each option according to their estimation about its prevalence and their judgment about the degree to which the behavior is ethically sound. 732 completed questionnaires were returned. According to the responses, the most ethical and the most unethical options are considered to be the most and the least prevalent behaviors among dentists practicing in Switzerland, respectively. Suggesting unnecessary treatments to patients seems to be an ethically unacceptable conduct in the eyes of a sample of dentists in Switzerland. Although the respondents believed their colleagues were very likely to behave in an ethical way in response to a situation that is susceptible to overtreatment, they still seemed to be concerned about the prevalence of unethical behaviors in this regard.

  8. Sources and distribution of microplastics in China's largest inland lake - Qinghai Lake.

    PubMed

    Xiong, Xiong; Zhang, Kai; Chen, Xianchuan; Shi, Huahong; Luo, Ze; Wu, Chenxi

    2018-04-01

    Microplastic pollution was studied in China's largest inland lake - Qinghai Lake in this work. Microplastics were detected with abundance varies from 0.05 × 10 5 to 7.58 × 10 5 items km -2 in the lake surface water, 0.03 × 10 5 to 0.31 × 10 5 items km -2 in the inflowing rivers, 50 to 1292 items m -2 in the lakeshore sediment, and 2 to 15 items per individual in the fish samples, respectively. Small microplastics (0.1-0.5 mm) dominated in the lake surface water while large microplastics (1-5 mm) are more abundant in the river samples. Microplastics were predominantly in sheet and fiber shapes in the lake and river water samples but were more diverse in the lakeshore sediment samples. Polymer types of microplastics were mainly polyethylene (PE) and polypropylene (PP) as identified using Raman Spectroscopy. Spatially, microplastic abundance was the highest in the central part of the lake, likely due to the transport of lake current. Based on the higher abundance of microplastics near the tourist access points, plastic wastes from tourism are considered as an important source of microplastics in Qinghai Lake. As an important area for wildlife conservation, better waste management practice should be implemented, and waste disposal and recycling infrastructures should be improved for the protection of Qinghai Lake. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. 77 FR 23123 - Special Local Regulation; Smokin The Lake; Gulfport Lake; Gulfport, MS

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-18

    ...-AA08 Special Local Regulation; Smokin The Lake; Gulfport Lake; Gulfport, MS AGENCY: Coast Guard, DHS... regulation for a portion of Gulfport Lake in Gulfport, MS. This action is necessary for the safeguard of... The Lake high speed boat races on May 5 and 6, 2012. Entry into, transiting or anchoring in this area...

  10. Modelling the economic losses of historic and present-day high-impact winter storms in Switzerland

    NASA Astrophysics Data System (ADS)

    Welker, Christoph; Stucki, Peter; Bresch, David; Dierer, Silke; Martius, Olivia; Brönnimann, Stefan

    2014-05-01

    Severe winter storms such as "Vivian" in February 1990 and "Lothar" in December 1999 are among the most destructive meteorological hazards in Switzerland. Disaster severity resulting from such windstorms is attributable, on the one hand, to hazardous weather conditions such as high wind gust speeds; and on the other hand to socio-economic factors such as population density, distribution of values at risk, and damage susceptibility. For present-day winter storms, the data basis is generally good to describe the meteorological development and wind forces as well as the associated socio-economic impacts. In contrast, the information on historic windstorms is overall sparse and the available historic weather and loss reports mostly do not provide quantitative information. This study illustrates a promising technique to simulate the economic impacts of both historic and present winter storms in Switzerland since end of the 19th century. Our approach makes use of the novel Twentieth Century Reanalysis (20CR) spanning 1871-present. The 2-degree spatial resolution of the global 20CR dataset is relatively coarse. Thus, the complex orography of Switzerland is not realistically represented, which has considerable ramifications for the representation of wind systems that are strongly influenced by the local orography, such as Föhn winds. Therefore, a dynamical downscaling of the 20CR to 3 km resolution using the Weather Research and Forecasting (WRF) model was performed, for in total 40 high-impact winter storms in Switzerland since 1871. Based on the downscaled wind gust speeds and the climada loss model, the estimated economic losses were calculated at municipality level for current economic and social conditions. With this approach, we find an answer to the question what would be the economic losses of e.g. a hazardous Föhn storm - which occurred in northern Switzerland in February 1925 - today, i.e. under current socio-economic conditions. Encouragingly, the pattern of

  11. Sediment deposition and selected water-quality characteristics in Cedar Lake and Lake Olathe, Northeast Kansas, 2000

    USGS Publications Warehouse

    Mau, D.P.

    2002-01-01

    The Lake Olathe watershed, located in northeast Kansas, was investigated using bathymetric survey data and reservoir bottom-sediment cores to determine sediment deposition, water-quality trends, and transport of nutrients (phosphorus and nitrogen species), selected trace elements, selected pesticides, and diatoms as indicators of eutrophic (organic-enriched and depleted oxygen supply) conditions. To determine sediment deposition and loads, bathymetric data from Cedar Lake and Lake Olathe, both located in the Lake Olathe watershed, were collected in 2000 and compared to historical topographic data collected when the lakes were built. Approximately 338 acre-feet of sediment deposition has occurred in Cedar Lake since dam closure in 1938, and 317 acre-feet has occurred at Lake Olathe since 1956. Mean annual sediment deposition was 5.45 acre-feet per year (0.89 acre-feet per year per square mile) for Cedar Lake and 7.0 acre-feet per year (0.42 acre-feet per year per square mile) for Lake Olathe. Mean annual sediment loads for the two reservoirs were 9.6 million pounds per year for Cedar Lake and 12.6 million pounds per year for Lake Olathe. Mean concentrations of total phosphorus in bottom-sediment samples from Cedar Lake ranged from 1,370 to 1,810 milligrams per kilogram, and concentrations in bottom-sediment samples from Lake Olathe ranged from 588 to 1,030 milligrams per kilogram. The implication of large total phosphorus concentrations in the bottom sediment of Cedar Lake is that inflow into Cedar Lake is rich in phosphorus and that adverse water-quality conditions could affect water quality in downstream Lake Olathe through discharge of water from Cedar Lake to Lake Olathe via Cedar Creek. Mean annual phosphorus loads transported from the Lake Olathe watershed were estimated to be 14,700 pounds per year for Cedar Lake and 9,720 pounds per year for Lake Olathe. The mean annual phosphorus yields were estimated to be 3.74 pounds per acre per year for Cedar Lake and 0

  12. Acoustic estimates of abundance and distribution of spawning lake trout on Sheboygan Reef in Lake Michigan

    USGS Publications Warehouse

    Warner, D.M.; Claramunt, R.M.; Janssen, J.; Jude, D.J.; Wattrus, N.

    2009-01-01

    Efforts to restore self-sustaining lake trout (Salvelinus namaycush) populations in the Laurentian Great Lakes have had widespread success in Lake Superior; but in other Great Lakes, populations of lake trout are maintained by stocking. Recruitment bottlenecks may be present at a number of stages of the reproduction process. To study eggs and fry, it is necessary to identify spawning locations, which is difficult in deep water. Acoustic sampling can be used to rapidly locate aggregations of fish (like spawning lake trout), describe their distribution, and estimate their abundance. To assess these capabilities for application to lake trout, we conducted an acoustic survey covering 22 km2 at Sheboygan Reef, a deep reef (<40 m summit) in southern Lake Michigan during fall 2005. Data collected with remotely operated vehicles (ROV) confirmed that fish were large lake trout, that lake trout were 1–2 m above bottom, and that spawning took place over specific habitat. Lake trout density exhibited a high degree of spatial structure (autocorrelation) up to a range of ~190 m, and highest lake trout and egg densities occurred over rough substrates (rubble and cobble) at the shallowest depths sampled (36–42 m). Mean lake trout density in the area surveyed (~2190 ha) was 5.8 fish/ha and the area surveyed contained an estimated 9500–16,000 large lake trout. Spatial aggregation in lake trout densities, similarity of depths and substrates at which high lake trout and egg densities occurred, and relatively low uncertainty in the lake trout density estimate indicate that acoustic sampling can be a useful complement to other sampling tools used in lake trout restoration research.

  13. Visualizing the geology of lake trout spawning sites, northern Lake Michigan

    USGS Publications Warehouse

    Dartnell, Peter; Barnes, Peter; Gardner, James V.; Lee, Kristen

    2004-01-01

    Geologists and biologists are working together to understand the links between lake floor geology (composition and shape) and the distribution of lake trout throughout their life cycle. Lake floor geology is one of the main factors determining where lake trout spawn, feed, and hide. In support of ongoing research to study Lake Michigan trout habitats, the U.S. Geological Survey in cooperation with the U.S. Army Corps of Engineers mapped the morphology of principle lake trout spawning sites. Using the Army Corps of Engineer's SHOALS airborne lidar (Light Detection and Ranging) system we mapped six regions in Northern Lake Michigan in order to identify ideal spawning regions composed of shallow, clean, gravel/cobble substrate, adjacent to deeper water. Lidar mapping systems, which use laser pulses to measure water depths from an airplane, are now available to map the nearshore lake morphology at meter-scale detail. Maps generated from the bathymetric data are used to define regions with smooth homogeneous substrate, regions with higher relief, and mixed regions with both smooth and rough relief. This morphologic information combined with sediment samples and direct bottom observations enable geologists to map areas with rougher relief composed of rock outcrop, boulders, and cobbles, as well as smooth regions covered with sand or mud. This information helps biologists, fishery managers, and ecologists visualize the lake floor in significant detail which promotes better fishery management, species protection, and habitat identification. These maps present the maps and discuss the geology of the six lake trout spawning sites mapped by the lidar system. Where the mapping approached land, aerial photography of the land is combined with the bathymetric data to help visualize the scale of the offshore features. Map and perspective views of Boulder Reef, Hog Island Reef, and Little Traverse Bay are shown on sheet 1, whereas map and perspective views of Trout and High Island

  14. Visualizing the geology of lake trout spawning sites; northern Lake Michigan

    USGS Publications Warehouse

    Dartnell, Peter; Barnes, Peter; Gardner, James V.; Lee, Kristen

    2006-01-01

    Geologists and biologists are working together to understand the links between lake floor geology (composition and shape) and the distribution of lake trout throughout their life cycle. Lake floor geology is one of the main factors determining where lake trout spawn, feed, and hide. In support of ongoing research to study Lake Michigan trout habitats, the U.S. Geological Survey in cooperation with the U.S. Army Corps of Engineers mapped the morphology of principle lake trout spawning sites. Using the Army Corps of Engineer's SHOALS airborne lidar (Light Detection and Ranging) system we mapped six regions in Northern Lake Michigan in order to identify ideal spawning regions composed of shallow, clean, gravel/cobble substrate, adjacent to deeper water. Lidar mapping systems, which use laser pulses to measure water depths from an airplane, are now available to map the nearshore lake morphology at meter-scale detail. Maps generated from the bathymetric data are used to define regions with smooth homogeneous substrate, regions with higher relief, and mixed regions with both smooth and rough relief. This morphologic information combined with sediment samples and direct bottom observations enable geologists to map areas with rougher relief composed of rock outcrop, boulders, and cobbles, as well as smooth regions covered with sand or mud. This information helps biologists, fishery managers, and ecologists visualize the lake floor in significant detail which promotes better fishery management, species protection, and habitat identification. These maps present the maps and discuss the geology of the six lake trout spawning sites mapped by the lidar system. Where the mapping approached land, aerial photography of the land is combined with the bathymetric data to help visualize the scale of the offshore features. Map and perspective views of Boulder Reef, Hog Island Reef, and Little Traverse Bay are shown on sheet 1, whereas map and perspective views of Trout and High Island

  15. A Killer Lake

    ERIC Educational Resources Information Center

    Horvath, Thomas

    2005-01-01

    In 1986, Lake Nyos, a volcanic lake in Cameroon, released a huge amount of carbon dioxide gas, killing over 1,700 people in the surrounding area. This case study, developed for use in a limnology or aquatic biology course, explores that event, introducing students to concepts relating to lake formation, thermal stratification, and dissolved gases.…

  16. LAKE-WETLAND LINKAGE AND PERIPHYTON DYNAMICS IN A LAKE SUPERIOR COASTAL WETLAND

    EPA Science Inventory

    Tributaries feeding coastal wetlands along the Wisconsin shore of Lake Superior are generally depleted in inorganic nitrogen (TIN) relative to phosphorus (SRP), while Lake Superior is phosphorous depleted and relatively rich in TIN. Within wetlands, mixing of tributary and lake w...

  17. Great Salt Lake, Utah

    USGS Publications Warehouse

    Stephens, Doyle W.; Gardner, Joe F.

    1999-01-01

    This document is intended as a source of general information and facts about Great Salt Lake, Utah. This U.S. Geological Survey information sheet answers frequently asked questions about Great Salt Lake. Topics include: History, salinity, brine shrimp, brine flies, migratory birds, and recreation. Great Salt Lake, the shrunken remnant of prehistoric Lake Bonneville, has no outlet. Dissolved salts accumulate in the lake by evaporation. Salinity south of the causeway has ranged from 6 percent to 27 percent over a period of 22 years (2 to 7 times saltier than the ocean). The high salinity supports a mineral industry that extracts about 2 million tons of salt from the lake each year. The aquatic ecosystem consists of more than 30 species of organisms. Harvest of its best-known species, the brine shrimp, annually supplies millions of pounds of food for the aquaculture industry worldwide. The lake is used extensively by millions of migratory and nesting birds and is a place of solitude for people. All this occurs in a lake that is located at the bottom of a 35,000-square-mile drainage basin that has a human population of more than 1.5 million.

  18. Spring-summer diet of lake trout on Six Fathom Bank and Yankee Reef in Lake Huron

    USGS Publications Warehouse

    Madenjian, C.P.; Holuszko, J.D.; Desorcie, T.J.

    2006-01-01

    We examined the stomach contents of 1,045 lake trout (Salvelinus namaycush) caught on Six Fathom Bank and Yankee Reef, two offshore reef complexes in Lake Huron, during late spring and early summer 1998-2003. Lake trout ranged in total length from 213 to 858 mm, and in age from 2 to 14 years. In total, 742 stomachs contained food. On a wet-weight basis, alewife (Alosa pseudoharengus) dominated the spring-summer diet of lake trout on both of these offshore reef complexes. Alewives accounted for 75 to 90% of lake trout diet, depending on the lake trout size category. Size of alewives found in lake trout stomachs increased with increasing lake trout size. Faster growth of juvenile lake trout on Six Fathom Bank and Yankee Reef than on Sheboygan Reef in Lake Michigan was attributed to greater availability of small alewives on the offshore reefs in Lake Huron. Our findings indicated that alewives inhabited Six Fathom Bank and Yankee Reef during spring and summer months. Thus, our study provided support for the contention that alewives may have interfered with natural reproduction by lake trout on these offshore reef complexes in Lake Huron.

  19. Geochemical Dataset of the Rhone River Delta (Lake Geneva) Sediments - Disentangling Human Impacts from Climate Change

    NASA Astrophysics Data System (ADS)

    Silva, T. A.; Girardclos, S.; Loizeau, J. L.

    2016-12-01

    Lake sediment records are often the most complete continental archives. In the last 200 years, in addition to climatic variability, humans have strongly impacted lake watersheds around the world. During the 20th century the Rhone River and its watershed upstream Lake Geneva (Switzerland/France) have been subject to river channelization, dam construction, water flow regulation, water and sediment abstraction as well as various land use changes. Under the scope of the SEDFATE project (Swiss National Science Foundation nº147689) we address human and climatic impact on the sediment transfer from the Rhone River watershed to Lake Geneva. Nineteen short sediment cores were collected in the Rhone River delta area in May 2014. Cores have been scanned with MSCL and XRF, sub-sampled every 1cm and 8 cores were dated by radiometric methods (137Cs and 210Pb). Photographs taken right after core opening were used for lithological description and in addition to MSCL data were used to correlate cores. Core dating shows that mass accumulation rates decreased in the 1964-1986 interval and then increased again in the interval between 1986-2014. XRF elements and ratios, known to indicate detrital sources (Al, Al/Si, Fe, K, Mn, Rb, Si, Ti, Ti/Ca), show that clastic input diminished from 1964 to 1986 and re-increased to the present. Other elemental (Zr/Rb, Zr/K, Si/Ti) and geophysical data (magnetic susceptibility) combined with lithology identify density flow deposits vs hemipelagic sedimentation. Changes in frequency of these event deposits indicate changes in the sedimentation patterns in the Rhone River sublacustrine delta during the last century. From these results we hypothesize that a significant sediment amount was abstracted from the system after the major dam constructions in the 1950's and that, since the 1990's, a contrary signal is due to increased sediment loads that follows glacial melting due to global warming.

  20. Water quality of Fremont Lake and New Fork Lakes, western Wyoming; a progress report

    USGS Publications Warehouse

    Peterson, D.A.; Averett, R.C.; Mora, K.L.

    1987-01-01

    Fremont Lake and New Fork Lakes in the New Fork River drainage of western Wyoming were selected for a comprehensive study of hydrologic processes affecting mountain lakes in the Rocky Mountains. Information is needed about lakes in this area to assess their response to existing and planned development. The concerns include regional issues such as acid precipitation from gas-sweetening plants, coal-fired powerplants, and smelters, as well as local issues, such as shoreline development and raising outlet control structures. Onsite measurements indicated strong thermal stratification in the lakes during the summer. Isothermal conditions occurred during December 1983 and May 1984. Mean phytoplankton concentrations were less than 5,000 cells/ml, and chlorophyll a concentrations were weakly correlated with phytoplankton concentrations. Zooplankton concentrations were small, less than 6 organisms/L. The numbers of benthic invertebrates/unit area in Fremont Lake were extremely small. The lake waters and inflow and outflow streams were chemically dilute solutions. Mean dissolved-solids concentrations were 13 mg/L in Fremont Lake and 24 mg/L in New Fork Lakes. Calcium and bicarbonate were the predominant ions. Concentrations of phosphorus and nitrogen usually were less than detection limits. Trace-metals concentrations in the lakes were similar to those in precipitation and generally were small. Dissolved organic-carbon concentrations were about 1 mg/L. Concentrations of fulvic and humic acids were relatively large in the inlet of Fremont Lake during the spring. Pine Creek has deposited 800 metric tons of sediment, on an annual average, to the delta of Fremont Lake. Most sediment is deposited during spring runoff. (USGS)

  1. Economic comparison of the monitoring programmes for bluetongue vectors in Austria and Switzerland.

    PubMed

    Pinior, B; Brugger, K; Köfer, J; Schwermer, H; Stockreiter, S; Loitsch, A; Rubel, F

    2015-05-02

    With the bluetongue virus serotype 8 (BTV-8) outbreak in 2006, vector monitoring programmes (according to EU regulation 1266/2007) were implemented by European countries to obtain information on the spatial distribution of vectors and the vector-free period. This study investigates the vector monitoring programmes in Austria and Switzerland by performing a retrospective cost analysis for the period 2006-2010. Two types of costs were distinguished: costs financed directly via the national bluetongue programmes and costs contributed in-kind by the responsible institutions and agricultural holdings. The total net costs of the monitoring programme in Austria amounted to €1,415,000, whereby in Switzerland the costs were valued at €94,000. Both countries followed the legislation complying with requirements, but differed in regard to sampling frequency, number of trap sites and sampling strategy. Furthermore, the surface area of Austria is twice the area of Switzerland although the number of ruminants is almost the same in both countries. Thus, for comparison, the costs were normalised with regard to the sampling frequency and the number of trap sites. Resulting costs per trap sample comprised €164 for Austria and €48 for Switzerland. In both countries, around 50 per cent of the total costs can be attributed to payments in-kind. The benefit of this study is twofold: first, veterinary authorities may use the results to improve the economic efficiency of future vector monitoring programmes. Second, the analysis of the payment in-kind contribution is of great importance to public authorities as it makes the available resources visible and demonstrates how they have been used. British Veterinary Association.

  2. Economic comparison of the monitoring programmes for bluetongue vectors in Austria and Switzerland

    PubMed Central

    Pinior, B.; Brugger, K.; Köfer, J.; Schwermer, H.; Stockreiter, S.; Loitsch, A.; Rubel, F.

    2015-01-01

    With the bluetongue virus serotype 8 (BTV-8) outbreak in 2006, vector monitoring programmes (according to EU regulation 1266/2007) were implemented by European countries to obtain information on the spatial distribution of vectors and the vector-free period. This study investigates the vector monitoring programmes in Austria and Switzerland by performing a retrospective cost analysis for the period 2006–2010. Two types of costs were distinguished: costs financed directly via the national bluetongue programmes and costs contributed in-kind by the responsible institutions and agricultural holdings. The total net costs of the monitoring programme in Austria amounted to €1,415,000, whereby in Switzerland the costs were valued at €94,000. Both countries followed the legislation complying with requirements, but differed in regard to sampling frequency, number of trap sites and sampling strategy. Furthermore, the surface area of Austria is twice the area of Switzerland although the number of ruminants is almost the same in both countries. Thus, for comparison, the costs were normalised with regard to the sampling frequency and the number of trap sites. Resulting costs per trap sample comprised €164 for Austria and €48 for Switzerland. In both countries, around 50 per cent of the total costs can be attributed to payments in-kind. The benefit of this study is twofold: first, veterinary authorities may use the results to improve the economic efficiency of future vector monitoring programmes. Second, the analysis of the payment in-kind contribution is of great importance to public authorities as it makes the available resources visible and demonstrates how they have been used. PMID:25841165

  3. Attoriolong Tradition of Lake Preservation

    NASA Astrophysics Data System (ADS)

    Mustamin, Kamaruddin; Rahmawati, Rahmawati; Abbas, Abbas; Akbar, Akbar

    2018-05-01

    Lake as a source of life for the fishermen has a very significant potential in influencing the views and behaviour of the fishing community’s culture. Events such as tidal lake erratic, flooding, high hardness water waves, even the lack of fish catches and the death of sailors in the lake, are symptoms that serve as the base outlook for the fishermen errors that they do against the unseen force which they consider to be the ruler of the lake. The fishing community of Lake Tempe has run attoriolong and established rules related to the management of the lake since the pre-Islamic period (before 1610 AD), led by a Macua Tappareng. Macua Tappareng is considered understand the ancestor details and rules in controlling the use of the lake, including the mystical of the lake. This study explores the local wisdom of coastal fishing communities of Lake Tempe in interacting with the lake led by Macua Tappareng. Macua Tappareng hereditary ensures that attoriolong tradition with all the rules and policies related to the lake is applied correctly. This research is a descriptive-analytic study that intends to describe as well as analyze the regulations and procedures on how Macua Tappareng in preserving the lake. The research shows that Macua Tappareng has the legitimacy and strategic position in protecting the lake, as evidenced by the continued preservation of some rules of fishing, such as a ban on fishing in particular place and time. Besides, the tradition of Maccera’ Tappareng is still considered liabilities fishing communities in honour of the ruler of the lake even become additional tools of the governments in disseminating and implementing local regulations.

  4. Contaminant trends in lake trout and walleye from the Laurentian Great Lakes

    USGS Publications Warehouse

    DeVault, David S.; Hesselberg, Robert J.; Rodgers, Paul W.; Feist, Timothy J.

    1996-01-01

    Trends in PCBs, DDT, and other contaminants have been monitored in Great Lakes lake trout and walleye since the 1970s using composite samples of whole fish. Dramatic declines have been observed in concentrations of PCB, ΣDDT, dieldrin, and oxychlordane, with declines initially following first order loss kinetics. Mean PCB concentrations in Lake Michigan lake trout increased from 13 μg/g in 1972 to 23 μg/g in 1974, then declined to 2.6 μg/g by 1986. Between 1986 and 1992 there was little change in concentration, with 3.5 μg/g observed in 1992. ΣDDT in Lake Michigan trout followed a similar trend, decreasing from 19.2 μg/g in 1970 to 1.1 μg/g in 1986, and 1.2 μg/g in 1992. Similar trends were observed for PCBs and ΣDDT in lake trout from Lakes Superior, Huron and Ontario. Concentrations of both PCB and ΣDDT in Lake Erie walleye declined between 1977 and 1982, after which concentrations were relatively constant through 1990. When originally implemented it was assumed that trends in the mean contaminant concentrations in open-lake fish would serve as cost effective surrogates to trends in the water column. While water column data are still extremely limited it appears that for PCBs in lakes Michigan and Superior, trends in lake trout do reasonably mimic those in the water column over the long term. Hypotheses to explain the trends in contaminant concentrations are briefly reviewed. The original first order loss kinetics used to describe the initial decline do not explain the more recent leveling off of contaminant concentrations. Recent theories have examined the possibilities of multiple contaminant pools. We suggest another hypothesis, that changes in the food web may have resulted in increased bioaccumulation. However, a preliminary exploration of this hypothesis using a change point analysis was inconclusive.

  5. Stability of lava lakes

    NASA Astrophysics Data System (ADS)

    Witham, Fred; Llewellin, Edward W.

    2006-11-01

    A physical model of a generic lava lake system is developed. We derive the requisite conditions for the existence of an 'equilibrium lava lake' in which magmastatic pressure at the base of the conduit balances the pressure in the underlying magmatic reservoir. The stability of this lava lake system is tested by investigating the response of the system to perturbation. We develop a graphical method, based on the system's pressure-depth profile, to predict the subsequent behaviour of the system. Despite the simplicity of the modelled system, we find a broad behavioural spectrum. Initially, the rise of bubbles through the magma is ignored. In this case, both stable, long-lived lava lakes, and unstable lakes that are prone to sudden draining, are predicted. The stability of the system is shown to be controlled by lake-conduit geometry, the solubility and gas expansion laws and the magma's volatile content. We show that an unstable lake must collapse to a new, stable equilibrium. Subsequent recharge of the system by, for example, conduit overturn, would promote a return to the original equilibrium, giving rise to cyclic behaviour. Such a mechanism is consistent with lava lake behaviour during the 1983-1984 Pu'u 'O'o eruption of Kilauea. When the rise of bubbles through the magma is considered, our model predicts that stable lakes must drain over time. We, therefore, deduce that persistently degassing, stable lava lakes, such as those observed at Mt. Erebus, Antarctica, and Mauna Ulu, Kilauea, Hawaii, must have an effective conduit convection mechanism or an exogenous supply of bubbles from depth.

  6. Increasing thiamine concentrations in lake trout eggs from Lakes Huron and Michigan coincide with low alewife abundance

    USGS Publications Warehouse

    Riley, Stephen C.; Rinchard, Jacques; Honeyfield, Dale C.; Evans, Allison N.; Begnoche, Linda

    2011-01-01

    Lake trout Salvelinus namaycush in the Laurentian Great Lakes suffer from thiamine deficiency as a result of adult lake trout consuming prey containing thiaminase, a thiamine-degrading enzyme. Sufficiently low egg thiamine concentrations result in direct mortality of or sublethal effects on newly hatched lake trout fry. To determine the prevalence and severity of low thiamine in lake trout eggs, we monitored thiamine concentrations in lake trout eggs from 15 sites in Lakes Huron and Michigan from 2001 to 2009. Lake trout egg thiamine concentrations at most sites in both lakes were initially low and increased over time at 11 of 15 sites, and the proportion of females with egg thiamine concentrations lower than the recommended management objective of 4 nmol/g decreased over time at eight sites. Egg thiamine concentrations at five of six sites in Lakes Huron and Michigan were significantly inversely related to site-specific estimates of mean abundance of alewives Alosa pseudoharengus, and successful natural reproduction of lake trout has been observed in Lake Huron since the alewife population crashed. These results support the hypothesis that low egg thiamine in Great Lakes lake trout is associated with increased alewife abundance and that low alewife abundance may currently be a prerequisite for successful reproduction by lake trout in the Great Lakes.

  7. Glacial lakes in the Indian Himalayas--from an area-wide glacial lake inventory to on-site and modeling based risk assessment of critical glacial lakes.

    PubMed

    Worni, Raphael; Huggel, Christian; Stoffel, Markus

    2013-12-01

    Glacial lake hazards and glacial lake distributions are investigated in many glaciated regions of the world, but comparably little attention has been given to these topics in the Indian Himalayas. In this study we present a first area-wide glacial lake inventory, including a qualitative classification at 251 glacial lakes >0.01 km(2). Lakes were detected in the five states spanning the Indian Himalayas, and lake distribution pattern and lake characteristics were found to differ significantly between regions. Three glacial lakes, from different geographic and climatic regions within the Indian Himalayas were then selected for a detailed risk assessment. Lake outburst probability, potential outburst magnitudes and associated damage were evaluated on the basis of high-resolution satellite imagery, field assessments and through the use of a dynamic model. The glacial lakes analyzed in the states of Jammu and Kashmir and Himachal Pradesh were found to present moderate risks to downstream villages, whereas the lake in Sikkim severely threatens downstream locations. At the study site in Sikkim, a dam breach could trigger drainage of ca. 16×10(6)m(3) water and generate maximum lake discharge of nearly 7000 m(3) s(-). The identification of critical glacial lakes in the Indian Himalayas and the detailed risk assessments at three specific sites allow prioritizing further investigations and help in the definition of risk reduction actions. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. What can the National Lake Assessment Tell Us about Ecosystem Service Benefits in Lakes

    EPA Science Inventory

    The condition of lakes, ponds, and reservoirs is often viewed as existing along a continuum from pristine to impacted. The 2007 National Lake Survey was conducted to assess the condition of the nation’s lakes. Over 1,000 lakes were surveyed and detailed physical and chemical da...

  9. Lake Enriquillo, Dominican Republic

    NASA Image and Video Library

    2017-08-15

    Lake Enriquillo is a hypersaline lake in the Dominican Republic. In 2004, the lake covered an area of 164 square kilometers; by 2011, it had doubled in size and grown to 350 km2, inundating farmland and homes. Various reasons for the flooding include increases in rainfall; increase of sediments going into the lake, raising the lakebed; and milder temperatures, reducing surface evaporation. The lake is home to the largest population of American crocodiles in the Caribbean. The images were acquired October 26, 2003 and June 10, 2017, cover an area of 22.7 by 45.4 km, and are located at 18.5 degrees north, 71.6 degrees west. An image of Lake Enriquillo taken in 2003 is available at https://photojournal.jpl.nasa.gov/catalog/PIA21815

  10. Natural hazard fatalities in Switzerland from 1946 to 2015

    NASA Astrophysics Data System (ADS)

    Badoux, Alexandre; Andres, Norina; Techel, Frank; Hegg, Christoph

    2016-12-01

    A database of fatalities caused by natural hazard processes in Switzerland was compiled for the period between 1946 and 2015. Using information from the Swiss flood and landslide damage database and the Swiss destructive avalanche database, the data set was extended back in time and more hazard processes were added by conducting an in-depth search of newspaper reports. The new database now covers all natural hazards common in Switzerland, categorised into seven process types: flood, landslide, rockfall, lightning, windstorm, avalanche and other processes (e.g. ice avalanches, earthquakes). Included were all fatal accidents associated with natural hazard processes in which victims did not expose themselves to an important danger on purpose. The database contains information on 635 natural hazard events causing 1023 fatalities, which corresponds to a mean of 14.6 victims per year. The most common causes of death were snow avalanches (37 %), followed by lightning (16 %), floods (12 %), windstorms (10 %), rockfall (8 %), landslides (7 %) and other processes (9 %). About 50 % of all victims died in one of the 507 single-fatality events; the other half were killed in the 128 multi-fatality events. The number of natural hazard fatalities that occurred annually during our 70-year study period ranged from 2 to 112 and exhibited a distinct decrease over time. While the number of victims in the first three decades (until 1975) ranged from 191 to 269 per decade, it ranged from 47 to 109 in the four following decades. This overall decrease was mainly driven by a considerable decline in the number of avalanche and lightning fatalities. About 75 % of victims were males in all natural hazard events considered together, and this ratio was roughly maintained in all individual process categories except landslides (lower) and other processes (higher). The ratio of male to female victims was most likely to be balanced when deaths occurred at home (in or near a building), a situation

  11. Life Sciences Start-ups in Switzerland: CTI and its Support for Young Entrepreneurs.

    PubMed

    Sekanina, Klara

    2014-12-01

    According to the Global Entrepreneurship Monitor 2013, perceived opportunities to start a business in Switzerland are high and rank above average compared to other innovation-based countries. 2013 was a record year for start-ups in Switzerland. Around 40,000 new businesses were recorded in the commercial register and the trend is set to continue. There are two main criteria that lead to success, particularly for science- or technology- based start-ups: first of all, it is the business or product idea itself, and secondly it is the entrepreneurial team. CTI is supporting innovation in a manner that responds to a need in the market identified by industry.

  12. Lake Erie...Take a Bow.

    ERIC Educational Resources Information Center

    Canning, Maureen; Dunlevy, Margie

    This elementary school teaching unit was developed as a part of a series of teaching units that deal with Lake Erie. This unit was developed to enable children to: (1) identify the Great Lakes and pick out Lake Erie on a map; (2) demonstrate knowledge of Lake Erie's origin and geography; (3) list some uses of Lake Erie; and (4) give examples of…

  13. Long-Term Variability of Satellite Lake Surface Water Temperatures in the Great Lakes

    NASA Astrophysics Data System (ADS)

    Gierach, M. M.; Matsumoto, K.; Holt, B.; McKinney, P. J.; Tokos, K.

    2014-12-01

    The Great Lakes are the largest group of freshwater lakes on Earth that approximately 37 million people depend upon for fresh drinking water, food, flood and drought mitigation, and natural resources that support industry, jobs, shipping and tourism. Recent reports have stated (e.g., the National Climate Assessment) that climate change can impact and exacerbate a range of risks to the Great Lakes, including changes in the range and distribution of certain fish species, increased invasive species and harmful algal blooms, declining beach health, and lengthened commercial navigation season. In this study, we will examine the impact of climate change on the Laurentian Great Lakes through investigation of long-term lake surface water temperatures (LSWT). We will use the ATSR Reprocessing for Climate: Lake Surface Water Temperature & Ice Cover (ARC-Lake) product over the period 1995-2012 to investigate individual and interlake variability. Specifically, we will quantify the seasonal amplitude of LSWTs, the first and last appearances of the 4°C isotherm (i.e., an important identifier of the seasonal evolution of the lakes denoting winter and summer stratification), and interpret these quantities in the context of global interannual climate variability such as ENSO.

  14. Side-scan sonar mapping of lake trout spawning habitat in northern Lake Michigan

    USGS Publications Warehouse

    Edsall, Thomas A.; Poe, Thomas P.; Nester, Robert T.; Brown, Charles L.

    1989-01-01

    Native stocks of lake trout Salvelinus namaycush were virtually or completely extirpated from the lower four Great Lakes by the early 1960s. The failure of early attempts to reestablish self-sustaining populations of lake trout was attributed partly to the practice of stocking hatcheryreared juveniles at locations and over substrates that had not been used in the past for spawning by native fish. Subsequent attempts to improve the selection of stocking locations were impeded by the lack of reliable information on the distribution of substrates on historical spawning grounds. Here we demonstrate the potential of side-scan sonar to substantially expand the data base needed to pinpoint the location of substrates where lake trout eggs, fry, or juveniles could be stocked to maximize survival and help ensure that survivors returning to spawn would encounter suitable substrates. We also describe the substrates and bathymetry of large areas on historical lake trout spawning grounds in the Fox Island Lake Trout Sanctuary in northern Lake Michigan. These areas could be used to support a contemporary self-sustaining lake trout population in the sanctuary and perhaps also in adjacent waters.

  15. Sexual difference in mercury concentrations of lake trout (Salvelinus namaycush) from Lake Ontario

    USGS Publications Warehouse

    Madenjian, C.P.; Keir, M.J.; Whittle, D.M.

    2011-01-01

    We determined total mercury (Hg) concentrations in 50 female lake trout (Salvelinus namaycush) and 69 male lake trout from Lake Ontario (Ontario, Canada and New York, United States). Results showed that, on average, males were 8% higher in Hg concentration than females in Lake Ontario. We also used bioenergetics modeling to determine whether a sexual difference in gross growth efficiency (GGE) could explain the observed sexual difference in Hg concentrations. According to the bioenergetics modeling results, male GGE was about 3% higher than female GGE, on average. Although the bioenergetics modeling could not explain the higher Hg concentrations exhibited by the males, a sexual difference in GGE remained a plausible explanation for the sexual difference in Hg concentrations of the lake trout. In an earlier study, male lake trout from Lake Ontario were found to be 22% higher in polychlorinated biphenyl (PCB) concentration than females from Lake Ontario. Thus, although males were higher in both Hg and PCB concentrations, the degree of the sexual difference in concentration varied between the two contaminants. Further research on sexual differences in Hg excretion rates and Hg direct uptake rates may be needed to resolve the disparity in results between the two contaminants.

  16. Recent lake ice-out phenology within and among lake districts of Alaska, U.S.A.

    USGS Publications Warehouse

    Arp, Christopher D.; Jones, Benjamin M.; Grosse, Guido

    2013-01-01

    The timing of ice-out in high latitudes is a fundamental threshold for lake ecosystems and an indicator of climate change. In lake-rich regions, the loss of ice cover also plays a key role in landscape and climatic processes. Thus, there is a need to understand lake ice phenology at multiple scales. In this study, we observed ice-out timing on 55 large lakes in 11 lake districts across Alaska from 2007 to 2012 using satellite imagery. Sensor networks in two lake districts validated satellite observations and provided comparison with smaller lakes. Over this 6 yr period, the mean lake ice-out for all lakes was 27 May and ranged from 07 May in Kenai to 06 July in Arctic Coastal Plain lake districts with relatively low inter-annual variability. Approximately 80% of the variation in ice-out timing was explained by the date of 0°C air temperature isotherm and lake area. Shoreline irregularity, watershed area, and river connectivity explained additional variation in some districts. Coherence in ice-out timing within the lakes of each district was consistently strong over this 6 yr period, ranging from r-values of 0.5 to 0.9. Inter-district analysis of coherence also showed synchronous ice-out patterns with the exception of the two arctic coastal districts where ice-out occurs later (June–July) and climatology is sea-ice influenced. These patterns of lake ice phenology provide a spatially extensive baseline describing short-term temporal variability, which will help decipher longer term trends in ice phenology and aid in representing the role of lake ice in land and climate models in northern landscapes.

  17. Mladotice Lake, Czechia: The unique genesis and evolution of the lake basin

    NASA Astrophysics Data System (ADS)

    Janský, Bohumír; Šobr, Miroslav; Kliment, Zdeněk; Chalupová, Dagmar

    2016-04-01

    The Mladotice Lake is a lake of unique genetic type in Czechia. In May 1872 a landslide as a result an extreme rainfall event occurred in western Czechia, blocking the Mladoticky stream valley and creating the Mladotice Lake. The 1952 and 1975 air images document that collective farming had a great impact on the lake basin evolution when balks and field terraces were removed and fields were made much larger. Because of this change in land use we expected higher soil erosion and a related increase in the sedimentation rate. First bathymetric measurements of the newly created lake were carried out in 1972 and were repeated in 1999, in 2003 and in 2014. Our analysis of the sedimentary record aims to identify the sediment stratigraphy, its basic physical and chemical properties, isotope content and thin sections yield a detailed temporal resolution of the sedimentation chronology. In some areas a sediment thickness of 4 m was detected. Hence, the average sedimentation rate is from 2.2 to 2.7 cm per year. KEY WORDS: Mladotice Lake - extreme rainfall event - landslide - land use changes - flood events - bathymetric measurements - sedimentation dynamics - stratigraphy and geochemistry of lake sediments - analyses of isotopes - sedimentation rates.

  18. Metal working fluid exposure and diseases in Switzerland.

    PubMed

    Koller, Michael F; Pletscher, Claudia; Scholz, Stefan M; Schneuwly, Philippe

    2016-07-01

    Exposure to metal working fluids (MWF) is common in machining processes worldwide and may lead to diseases of the skin and the respiratory tract. The aim of the study was to investigate exposure and diseases due to MWF in Switzerland between 2004 and 2013. We performed descriptive statistics including determination of median and 90th percentile values of MWF concentrations listed in a database of Suva. Moreover, we clustered MWF-induced occupational diseases listed in a database from the Swiss Central Office for Statistics in Accident Insurance, and performed linear regression over time to investigate temporal course of the illnesses. The 90th percentile for MWF air concentration was 8.1 mg (aerosol + vapor)/m 3 and 0.9 mg aerosol/m 3 (inhalable fraction). One thousand two hundred and eighty skin diseases and 96 respiratory diseases were observed. This is the first investigation describing exposure to and diseases due to MWF in Switzerland over a timeframe of 10 years. In general, working conditions in the companies of this investigation were acceptable. Most measured MWF concentrations were below both the Swiss and most international occupational exposure limits of 2014. The percentage of workers declared unfit for work was 17% compared to the average of other occupational diseases (12%).

  19. Cochlear implantation in children and adults in Switzerland.

    PubMed

    Brand, Yves; Senn, Pascal; Kompis, Martin; Dillier, Norbert; Allum, John H J

    2014-02-04

    The cochlear implant (CI) is one of the most successful neural prostheses developed to date. It offers artificial hearing to individuals with profound sensorineural hearing loss and with insufficient benefit from conventional hearing aids. The first implants available some 30 years ago provided a limited sensation of sound. The benefit for users of these early systems was mostly a facilitation of lip-reading based communication rather than an understanding of speech. Considerable progress has been made since then. Modern, multichannel implant systems feature complex speech processing strategies, high stimulation rates and multiple sites of stimulation in the cochlea. Equipped with such a state-of-the-art system, the majority of recipients today can communicate orally without visual cues and can even use the telephone. The impact of CIs on deaf individuals and on the deaf community has thus been exceptional. To date, more than 300,000 patients worldwide have received CIs. In Switzerland, the first implantation was performed in 1977 and, as of 2012, over 2,000 systems have been implanted with a current rate of around 150 CIs per year. The primary purpose of this article is to provide a contemporary overview of cochlear implantation, emphasising the situation in Switzerland.

  20. Lake Garda, Italy

    NASA Image and Video Library

    2001-07-21

    This ASTER image was acquired on July 29, 2000 and covers an area of 30 by 57 km in northern Italy. Lake Garda was formed by glaciers during the last Ice Age, and is Italy's largest lake. Lago di Garda lies in the provinces of Verona, Brescia, and Trento, and is 51 kilometers (32 miles) long and from 3 to 18 kilometers (2 to 11 miles) wide. The Sarca is its chief affluent, and the lake is drained southward by the Mincio, which discharges into the Po River. Many villas are situated on its shores. On the peninsula of Sirmione, at the southern end of the lake, are the ruins of a Roman villa and a castle of the Scaligers, an Italian family of the 16th century. The RIGHT image has the land area masked out, and a harsh stretch was applied to the lake values to display variations in sediment load. Also visible are hundreds of boats and their wakes, criss-crossing the lake. The image is centered at 45.6 degrees north latitude, 10.6 degrees east longitude. http://photojournal.jpl.nasa.gov/catalog/PIA02671

  1. Practical Considerations in Donation After Circulatory Determination of Death in Switzerland.

    PubMed

    Dalle Ave, Anne L; Shaw, David M; Elger, Bernice

    2017-09-01

    Faced with similar issues of organ scarcity to its neighbors, Switzerland has developed donation after circulatory determination of death (DCDD) as a way to expand the organ pool since 1985. Here, we analyze the history, practical considerations, and ethical issues relating to the Swiss donation after circulatory death programs. In Switzerland, determination of death for DCDD requires a stand-off period of 10 minutes. This time between cardiac arrest and the declaration of death is mandated in the guidelines of the Swiss Academy of Medical Sciences. As in other DCDD programs, safeguards are put to avoid physicians denying lifesaving treatment to savable patients because of being influenced by receivers' interest. An additional recommendation could be made: Recipients should be transparently informed of the worse graft outcomes with DCDD programs and given the possibility to refuse such organs.

  2. Airborne lidar detection and mapping of invasive lake trout in Yellowstone Lake.

    PubMed

    Roddewig, Michael R; Churnside, James H; Hauer, F Richard; Williams, Jacob; Bigelow, Patricia E; Koel, Todd M; Shaw, Joseph A

    2018-05-20

    The use of airborne lidar to survey fisheries has not yet been extensively applied in freshwater environments. In this study, we investigated the applicability of this technology to identify invasive lake trout (Salvelinus namaycush) in Yellowstone Lake, Yellowstone National Park, USA. Results of experimental trials conducted in 2004 and in 2015-16 provided lidar data that identified groups of fish coherent with current knowledge and models of lake trout spawning sites, and one identified site was later confirmed to have lake trout.

  3. Patterns in Benthic Biodiversity Link Lake Trophic Status to Structure and Potential Function of Three Large, Deep Lakes

    PubMed Central

    Hayford, Barbara L.; Caires, Andrea M.; Chandra, Sudeep; Girdner, Scott F.

    2015-01-01

    Relative to their scarcity, large, deep lakes support a large proportion of the world’s freshwater species. This biodiversity is threatened by human development and is in need of conservation. Direct comparison of biodiversity is the basis of biological monitoring for conservation but is difficult to conduct between large, insular ecosystems. The objective of our study was to conduct such a comparison of benthic biodiversity between three of the world’s largest lakes: Lake Tahoe, USA; Lake Hövsgöl, Mongolia; and Crater Lake, USA. We examined biodiversity of common benthic organism, the non-biting midges (Chironomidae) and determined lake trophic status using chironomid-based lake typology, tested whether community structure was similar between the three lakes despite geographic distance; and tested whether chironomid diversity would show significant variation within and between lakes. Typology analysis indicated that Lake Hövsgöl was ultra-oligotrophic, Crater Lake was oligotrophic, and Lake Tahoe was borderline oligotrophic/mesotrophic. These results were similar to traditional pelagic measures of lake trophic status for Lake Hövsgöl and Crater Lake but differed for Lake Tahoe, which has been designated as ultra-oligotrophic by traditional pelagic measures such as transparency found in the literature. Analysis of similarity showed that Lake Tahoe and Lake Hövsgöl chironomid communities were more similar to each other than either was to Crater Lake communities. Diversity varied between the three lakes and spatially within each lake. This research shows that chironomid communities from these large lakes were sensitive to trophic conditions. Chironomid communities were similar between the deep environments of Lake Hövsgöl and Lake Tahoe, indicating that chironomid communities from these lakes may be useful in comparing trophic state changes in large lakes. Spatial variation in Lake Tahoe’s diversity is indicative of differential response of chironomid

  4. Status of lake trout rehabilitation on Six Fathom Bank and Yankee Reef in Lake Huron

    USGS Publications Warehouse

    Madenjian, Charles P.; DeSorcie, Timothy J.; McClain, Jerry R.; Woldt, Aaron P.; Holuszko, Jeffrey D.; Bowen, Charles A.

    2004-01-01

    Six Fathom Bank, an offshore reef in the central region of Lake Huron's main basin, was stocked annually with hatchery-reared lake trout Salvelinus namaycush during 1985–1998, and nearby Yankee Reef was stocked with hatchery-reared lake trout in 1992, 1997, and annually during 1999–2001. We conducted gill-net surveys during spring and fall to evaluate performances of each of the various strains of lake trout, as well as the performance of the entire lake trout population (all strains pooled), on these two offshore reefs during 1992–2000. Criteria to evaluate performance included the proportion of “wild” fish within the population, spawner density, adult survival, growth, maturity, and wounding rate by sea lamprey Petromyzon marinus. Although naturally reproduced age-0 lake trout fry were caught on Six Fathom Bank and Yankee Reef, wild lake trout did not recruit to the adult population to any detectable degree. The density of spawning lake trout on Six Fathom Bank (>100 fish/305 m of gill net) during 1995–1998 appeared to be sufficiently high to initiate a self-sustaining population. However, annual mortality estimates for all lake trout strains pooled from catch curve analyses ranged from 0.48 to 0.62, well exceeding the target level of 0.40 suggested for lake trout rehabilitation. Annual mortality rate for the Seneca Lake strain (0.34) was significantly lower than that for the Superior–Marquette (0.69) and Lewis Lake (0.69) strains. This disparity in survival among strains was probably attributable to the lower sea-lamprey-induced mortality experienced by the Seneca Lake strain. The relatively high mortality experienced by adult lake trout partly contributed to the lack of successful natural recruitment to the adult population on these offshore reefs, but other factors were probably also involved. We recommend that both stocking of the Seneca Lake strain and enhanced efforts to reduce sea lamprey abundance in Lake Huron be continued.

  5. Temperate Lakes Discovered on Titan

    NASA Astrophysics Data System (ADS)

    Vixie, Graham; Barnes, Jason W.; Jackson, Brian; Wilson, Paul

    2012-04-01

    We have discovered two temperate lakes on Titan using Cassini's Visual and Infrared Mapping Spectrometer (VIMS). Three key features help to identify these surface features as lakes: morphology, albedo, and specular reflection. The presence of lakes at the mid-latitudes mean liquid can accumulate and remain stable outside of the poles. We first identify a lake surface by looking for possible shorelines with a lacustrine morphology. Then, we apply a simple atmospheric correction that produces an approximate surface albedo. Next, we prepare cylindrical projection maps of the brightness of the sky as seen from any points on the surface to identify specular reflections. Our techniques can then be applied to other areas, such as Arrakis Planitia, to test for liquid. Currently, all the known lakes on Titan are concentrated at the poles. Lakes have been suggested in the tropic zone by Griffith et al. Our discovery of non-transient, temperate lakes has important implications for Titan's hydrologic cycle. Clouds have been recorded accumulating in the mid-latitudes and areas have been darkened by rainfall but later brightened after evaporation (Turtle et al. 2011). Stable temperate lakes would affect total rainfall, liquid accumulation, evaporation rates, and infiltration. Polaznik Macula (Figure 1) is a great candidate for lake filling, evaporation rates, and stability. References: Griffith, C., et al.: "Evidence for Lakes on Titan's Tropical Surface". AAS/Division for Planetary Sciences Meeting Abstracts #42, Vol. 42, pp. 1077, 2010. Turtle, E. P., et al.: "Rapid and Extensive Surface Changes Near Titan's Equator: Evidence of April Showers". Science, Vol. 331, pp. 1414-, 2011. Figure 1: Polaznik Macula is the large, dark area central to the figure. The encircled dark blue areas represent positively identified lake regions in the T66 flyby. The light blue areas represent lake candidates still under analysis. The green circle marks a non-lake surface feature enclosed by a

  6. 14 CFR 93.69 - Special requirements, Lake Campbell and Sixmile Lake Airports.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES... person operating an aircraft to or from Lake Campbell or Sixmile Lake Airport shall conform to the flow of traffic for the Lake operations that are depicted on the appropriate aeronautical charts. ...

  7. 14 CFR 93.69 - Special requirements, Lake Campbell and Sixmile Lake Airports.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES... person operating an aircraft to or from Lake Campbell or Sixmile Lake Airport shall conform to the flow of traffic for the Lake operations that are depicted on the appropriate aeronautical charts. ...

  8. 14 CFR 93.69 - Special requirements, Lake Campbell and Sixmile Lake Airports.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES... person operating an aircraft to or from Lake Campbell or Sixmile Lake Airport shall conform to the flow of traffic for the Lake operations that are depicted on the appropriate aeronautical charts. ...

  9. 14 CFR 93.69 - Special requirements, Lake Campbell and Sixmile Lake Airports.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES... person operating an aircraft to or from Lake Campbell or Sixmile Lake Airport shall conform to the flow of traffic for the Lake operations that are depicted on the appropriate aeronautical charts. ...

  10. 14 CFR 93.69 - Special requirements, Lake Campbell and Sixmile Lake Airports.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES... person operating an aircraft to or from Lake Campbell or Sixmile Lake Airport shall conform to the flow of traffic for the Lake operations that are depicted on the appropriate aeronautical charts. ...

  11. The Volume of Earth's Lakes

    NASA Astrophysics Data System (ADS)

    Cael, B. B.

    How much water do lakes on Earth hold? Global lake volume estimates are scarce, highly variable, and poorly documented. We develop a mechanistic null model for estimating global lake mean depth and volume based on a statistical topographic approach to Earth's surface. The volume-area scaling prediction is accurate and consistent within and across lake datasets spanning diverse regions. We applied these relationships to a global lake area census to estimate global lake volume and depth. The volume of Earth's lakes is 199,000 km3 (95% confidence interval 196,000-202,000 km3) . This volume is in the range of historical estimates (166,000-280,000 km3) , but the overall mean depth of 41.8 m (95% CI 41.2-42.4 m) is significantly lower than previous estimates (62 - 151 m). These results highlight and constrain the relative scarcity of lake waters in the hydrosphere and have implications for the role of lakes in global biogeochemical cycles. We also evaluate the size (area) distribution of lakes on Earth compared to expectations from percolation theory. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. 2388357.

  12. Response of slimy sculpins to predation by juvenile lake trout in southern Lake Ontario

    USGS Publications Warehouse

    Owens, Randall W.; Bergstedt, Roger A.

    1994-01-01

    Abundance and biomass of slimy sculpin Cottus cognatus declined in Lake Ontario at depths most frequently occupied by juvenile lake trout Salvelinus namaycush (<70 m), but not at greater depths, during 1980–1987. The abundance of juvenile lake trout increased at depths less than 70 m between 1980 and 1987, and slimy sculpin abundance was negatively correlated with lake trout abundance. The size of slimy sculpins caught at depths less than 70 m decreased between 1980 and 1987, fish 50–99 mm becoming less common and fish 100 mm or longer becoming rare. The size of slimy sculpins at depths greater than 70 m did not change, Because slimy sculpins are the principal fish eaten by juvenile lake trout, and because juvenile lake trout were most abundant at depths where the greatest changes in the slimy sculpin population took place, we conclude that juvenile lake trout in Lake Ontario altered the slimy sculpin population. No significant negative correlations were found between abundance of slimy sculpins and those of the two most abundant fishes in Lake Ontario: Alewife Alosa pseudoharengus and rainbow smeltOsmerus mordax.

  13. Real-estate lakes

    USGS Publications Warehouse

    Rickert, David A.; Spieker, Andrew Maute

    1971-01-01

    Since the dawn of civilization waterfront land has been an irresistible attraction to man. Throughout history he has sought out locations fronting on oceans, rivers, and lakes. Originally sought for proximity .to water supply and transportation, such locations are now sought more for their esthetic qualities and for recreation. Usable natural waterfront property is limited, however, and the more desirable sites in many of our urban areas have already been taken. The lack of available waterfront sites has led to the creation of many artificial bodies of water. The rapid suburbanization that has characterized urban growth in America since the end of World War II, together with increasing affluence and le-isure time, has created a ready market for waterfront property. Accordingly, lake-centered subdivisions and developments dot the suburban landscape in many of our major urban areas. Literally thousands of lakes surrounded by homes have materialized during this period of rapid growth. Recently, several "new town" communities have been planned around this lake-centered concept. A lake can be either an asset or a liaoility to a community. A clean, clear, attractively landscaped lake is a definite asset, whereas a weed-choked, foul-smelling mudhole is a distinct liability. The urban environment poses both problems and imaginative opportunities in the development of lakes. Creation of a lake causes changes in all aspects of the environment. Hydrologic systems and ecological patterns are usually most severely altered. The developer should be aware of the potential changes; it is not sufficient merely to build a dam across a stream or to dig a hole in the ground. Development of Gl a successful lake requires careful planning for site selection and design, followed by thorough and cc ntinual management. The purpose of this report is to describe the characteristics of real-estate lakes, to pinpoint potential pmblems, and to suggest possible planning and management guidelines

  14. Modelling economic losses of historic and present-day high-impact winter storms in Switzerland

    NASA Astrophysics Data System (ADS)

    Welker, Christoph; Martius, Olivia; Stucki, Peter; Bresch, David; Dierer, Silke; Brönnimann, Stefan

    2015-04-01

    Windstorms can cause significant financial damage and they rank among the most hazardous meteorological hazards in Switzerland. Risk associated with windstorms involves the combination of hazardous weather conditions, such as high wind gust speeds, and socio-economic factors, such as the distribution of assets as well as their susceptibilities to damage. A sophisticated risk assessment is important in a wide range of areas and has benefits for e.g. the insurance industry. However, a sophisticated risk assessment needs a large sample of storm events for which high-resolution, quantitative meteorological and/or loss data are available. Latter is typically an aggravating factor. For present-day windstorms in Switzerland, the data basis is generally sufficient to describe the meteorological development and wind forces as well as the associated impacts. In contrast, historic windstorms are usually described by graphical depictions of the event and/or by weather and loss reports. The information on historic weather events is overall sparse and the available historic weather and loss reports mostly do not provide quantitative information. It has primarily been the field of activity of environmental historians to study historic weather extremes and their impacts. Furthermore, the scarce availability of atmospheric datasets reaching back sufficiently in time has so far limited the analysis of historic weather events. The Twentieth Century Reanalysis (20CR) ensemble dataset, a global atmospheric reanalysis currently spanning 1871 to 2012, offers potentially a very valuable resource for the analysis of historic weather events. However, the 2°×2° latitude-longitude grid of the 20CR is too coarse to realistically represent the complex orography of Switzerland, which has considerable ramifications for the representation of smaller-scale features of the surface wind field influenced by the local orography. Using the 20CR as a starting point, this study illustrates a method to

  15. Circulation and sedimentation in a tidal-influenced fjord lake: Lake McKerrow, New Zealand

    NASA Astrophysics Data System (ADS)

    Pickrill, R. A.; Irwin, J.; Shakespeare, B. S.

    1981-01-01

    Lake McKerrow is a tide-influenced fjord lake, separated from the open sea by a Holocene barrier spit. Fresh, oxygenated waters of the epilimnion overlie saline, deoxygenated waters of the hypolimnion. During winter, water from the Upper Hollyford River interflows along the pycnocline, depositing coarse silt on the steep delta and transporting finer sediment down-lake. An extensive sub-lacustrine channel system on the foreset delta slope is possibly maintained by turbidity currents. Saline waters of the hypolimnion are periodically replenished. During high tides and low lake levels saline water flows into the lake and downslope into the lake basin as a density current in a well defined channel.

  16. Lake Eyre

    Atmospheric Science Data Center

    2013-04-16

    ... lake, and becomes dense with birds, frogs and colorful plant life. The Lake responds to extended dry periods (often associated with El Niño ... NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission Directorate, Washington, D.C. The Terra spacecraft is managed ...

  17. Hydrogeologic controls on the groundwater interactions with an acidic lake in karst terrain, Lake Barco, Florida

    USGS Publications Warehouse

    Lee, T.M.

    1996-01-01

    Transient groundwater interactions and lake stage were simulated for Lake Barco, an acidic seepage lake in the mantled karst of north central Florida. Karst subsidence features affected groundwater flow patterns in the basin and groundwater fluxes to and from the lake. Subsidence features peripheral to the lake intercepted potential groundwater inflow and increased leakage from the shallow perimeter of the lake bed. Simulated groundwater fluxes were checked against net groundwater flow derived from a detailed lake hydrologic budget with short-term lake evaporation computed by the energy budget method. Discrepancies between modeled and budget-derived net groundwater flows indicated that the model underestimated groundwater inflow, possibly contributed to by transient water table mounding near the lake. Recharge from rainfall reduced lake leakage by 10 to 15 times more than it increased groundwater inflow. As a result of the karst setting, the contributing groundwater basin to the lake was 2.4 ha for simulated average rainfall conditions, compared to the topographically derived drainage basin area of 81 ha. Short groundwater inflow path lines and rapid travel times limit the contribution of acid-neutralizing solutes from the basin, making Lake Barco susceptible to increased acidification by acid rain.

  18. Genetic variability among lake whitefish from Isle Royale and the Upper Great Lakes

    USGS Publications Warehouse

    Stott, Wendylee; Todd, Thomas N.; Kallemeyn, Larry

    2004-01-01

    The coregonine fishes from Isle Royale National Park represent a unique group that has escaped the successional changes observed elsewhere in North America. Analysis of microsatellite DNA loci revealed significant genetic differences among samples of lake whitefish (Coregonus clupeaformis) from Isle Royale, Lake Superior, and Lake Huron. The amount of genetic variation observed is consistent with that seen in other studies of whitefishes from North America. The lake whitefish from Isle Royale had previously been assigned sub-species status, but no evidence was found to support this. The effects of common ancestry and demographics both play a role in determining the relatedness of the populations. As with other fish species from Isle Royale and the upper Great Lakes, the lake whitefish have their origins in the Mississippi refugium.

  19. Some aspects of the reform of the health care systems in Austria, Germany and Switzerland.

    PubMed

    Theurl, E

    1999-01-01

    The health care systems in Austria, Germany and Switzerland owe their institutional structure to different historical developments. While Austria and Germany voted for the Bismarck-Model of social health insurance, Switzerland adopted a voluntary system of health insurance. In all three countries, until very recently, the different challenges which the health care sector faced were met by piecemeal approaches and by stop and go policies, which, in the long run were not very successful either in containing costs or in improving efficacy and efficiency. During the 1990 more fundamental reforms in the health care systems of all three countries took place. Germany and Switzerland chose the path of deregulation of the health insurance system, which consequently strengthened the competition between the insurance companies, and, to some extent between the suppliers of medical services. While this can be seen as an essential part of the reform process for these two countries. Austria favors a state-oriented and interventionist approach in order to meet the challenges.

  20. Water quality of selected lakes in Mount Rainier National Park, Washington with respect to lake acidification

    USGS Publications Warehouse

    Turney, G.L.; Dion, N.P.; Sumioka, S.S.

    1986-01-01

    Thirteen lakes in Mount Rainier National Park were evaluated for general chemical characteristics, sensitivity to acidification by acidic precipitation, and degree of existing acidification. The lakes studies were Allen, one of the Chenuis group, Crescent , Crystal, Eleanor, Fan, one of the Golden group, Marsh, Mowich, Mystic, Shriner, and two unnamed lakes. The lakes were sampled in August 1983. Specific conductance values were generally 21 microsiemens/cm at 25 C or less, and dissolved solids concentrations were generally 20 mg/L or less. The major cations were calcium and sodium, and the major anion was bicarbonate. Alkalinity concentrations ranged from 2.1 to 9.0 mg/L in 12 of the lakes. Allen Lake was the exception, having an alkalinity concentration of 27 mg/L. The pH values for all of the lakes ranged from 5.8 to 6.5. In most of the lakes, vertical profiles of temperature, dissolved oxygen, pH, and specific conductance were relatively uniform. In the deeper lakes, temperature decreased with depth and dissolved-oxygen concentrations increased to about 20 feet, remained constant to 80 ft, then decreased with increasing depth. Exceptions to general water quality patterns were observed in three lakes. Allen Lake had a specific conductance value of 58 Microsiemens/cm. The lake of the Golden group was anaerobic at the bottom and had relatively high concentrations of dissolved organic carbon and dissolved metals, and a lower light transmission than the other lakes studied. One of the unnamed lakes had relatively high concentrations of phytoplankton and dissolved organic carbon and relatively low levels of light transmission. Comparisons of lake data to acid-sensitivity thresholds for specific conductance and alkalinity indicated that all of the lakes except Allen would be sensitive to acidic precipitation. The small sizes of the lakes, and their locations in basins of high precipitation and weathering-resistant rock types, enhance their sensitivity. None of the

  1. Discrimination among spawning concentrations of Lake Superior lake herring based on trace element profiles in sagittae

    USGS Publications Warehouse

    Bronte, Charles R.; Hesselberg, Robert J.; Shoesmith, John A.; Hoff, Michael H.

    1996-01-01

    Little is known about the stock structure of lake herring Coregonus artedi in Lake Superior, and recent increases in harvestable stock sizes has led to expanded exploitation in some areas. Research on marine teleosts has demonstrated that chemical differences in sagittal otoliths can be used for identification of fish stocks. We used plasma emission spectrophotometry to measure the concentrations of 10 trace elements in the sagittal otoliths from lake herring captured at eight spawning sites in Lake Superior and from Little Star Lake, an inland lake outside the Lake Superior basin. Discriminant function analysis indicated that elemental concentrations provided site-specific information but that considerable overlap existed among some locations, especially those in western Lake Superior. Correct classification rates varied from 12.0% to 86.1% and were generally higher for spawning locations from embayments in eastern Lake Superior and for the outgroup population from Little Star Lake. The results presented here demonstrate the potential usefulness of this technique for strictly freshwater species, especially those that live in highly oligotrophic waters such as Lake Superior.

  2. Limnology of Botos Lake, a tropical crater lake in Costa Rica.

    PubMed

    Umaña, G

    2001-12-01

    Botos Lake, located at the Poas Volcano complex (Costa Rica) was sampled eight times from 1994 to 1996 for physicochemical conditions of the water column and phytoplanktonic community composition. Depth was measured at fixed intervals in several transects across the lake to determine its main morphometric characteristics. The lake has an outlet to the north. It is located 2580 m above sea level and is shallow, with a mean depth of 1.8 m and a relative depth of 2.42 (surface area 10.33 ha, estimated volume 47.3 hm3). The lake showed an isothermal water column in all occasions, but it heats and cools completely according to weather fluctuations. Water transparency reached the bottom on most occasions (> 9 m). The results support the idea that the lake is polymictic and oligotrophic. The lake has at least 23 species of planktonic algae, but it was always dominated by dinoflagellates, especially Peridinium inconspicuum. The shore line is populated by a sparse population of Isoetes sp. and Eleocharis sp. mainly in the northern shore where the bottom has a gentle slope and the forest does not reach the shore.

  3. Antibiotics and Antibiotic Resistance Genes in Sediment of Honghu Lake and East Dongting Lake, China.

    PubMed

    Yang, Yuyi; Cao, Xinhua; Lin, Hui; Wang, Jun

    2016-11-01

    Sediment is an ideal medium for the aggregation and dissemination of antibiotics and antibiotic resistance genes (ARGs). The levels of antibiotics and ARGs in Honghu Lake and East Dongting Lake of central China were investigated in this study. The concentrations of eight antibiotics (four sulfonamides and four tetracyclines) in Honghu Lake were in the range 90.00-437.43 μg kg -1 (dry weight (dw)) with mean value of 278.21 μg kg -1 dw, which was significantly higher than those in East Dongting Lake (60.02-321.04 μg kg -1 dw, mean value of 195.70 μg kg -1 dw). Among the tested three sulfonamide resistance genes (sul) and eight tetracycline resistance genes (tet), sul1, sul2, tetA, tetC, and tetM had 100 % detection frequency in sediment samples of East Dongting Lake, while only sul1, sul2, and tetC were observed in all samples of Honghu Lake. The relative abundance of sul2 was higher than that of sul1 at p < 0.05 level in both lakes. The relative abundance of tet genes in East Dongting Lake was in the following order: tetM > tetB > tetC > tetA. The relative abundance of sul1, sul2, and tetC in East Dongting Lake was significantly higher than those in Honghu Lake. The abundance of background bacteria may play an important role in the horizontal spread of sul2 and tetC genes in Honghu Lake and sul1 in East Dongting Lake, respectively. Redundancy analysis indicated that tetracyclines may play a more important role than sulfonamides in the abundance of sul1, sul2, and tetC gens in Honghu Lake and East Dongting Lake.

  4. Functional convergence among pelagic sculpins of Lake Baikal and deepwater ciscoes of the Great Lakes

    USGS Publications Warehouse

    Eshenroder, Randy L.; Sideleva, Valentina G.; Todd, Thomas N.

    1999-01-01

    The vast, well-oxygenated hypolimnia of Lake Baikal and the Great Lakes were both dominated by endemic planktivorous fishes. These dominants, two species of sculpins (Comephorus, Comephoridae) in Lake Baikal and six species of deepwater ciscoes (Coregonus, Salmonidae) in the Great Lakes, although distant taxonomically, have morphologies suggesting a surprising degree of functional convergence. Here it is proposed that the same two buoyancy-regulation strategies observed in Baikal sculpins also arose in the deepwater ciscoes of the Great Lakes. One strategy favors hydrostatic lift (generated by low specific gravity) and is characterized by fatter, larger-bodied fish with smaller paired fins; the second strategy favors hydrodynamic lift (generated by swimming) and is characterized by leaner, smaller-bodied fish with larger paired fins. Both types likely evolved to feed on a single species of ecologically analogous, vertically migrating macrozooplankter: Macrohectopus branickii in Lake Baikal and Mysis relicta in the Great Lakes. It is suggested that Coregonus did not diversify and proliferate in Lake Baikal as they did in the Great Lakes because by the time Coregonus colonized Lake Baikal, pelagic sculpins were already dominant.

  5. LAKE FORK

    EPA Science Inventory

    The Lake Fork of the Arkansas River Watershed has been adversely affected through mining, water diversion and storage projects, grazing, logging, and other human influences over the past 120 years. It is the goals of the LFWWG to improve the health of Lake fork by addressing th...

  6. [Chronology of horseshoes found in Switzerland].

    PubMed

    Imhof, U

    2004-01-01

    The horse was domesticated by a people in Central Asia. However, it is not known where and who invented horse shoeing, an invention that increased the possibilities for using horses. The word "horseshoe" was first mentioned in a document from 826 p.c. Up to now an archaeologist couldn't date an excavated horseshoe. I succeeded now to establish a chronology for horseshoes found in Switzerland. The first realisation is that in the course of more than thousand years of horse shoeing history three basic forms followed each other. Moreover, the existing horseshoes can be allocated to periodical types, each in use for approximately a quarter of a century.

  7. Usefulness of natural regions for lake management: Analysis of variation among lakes in northwestern Wisconsin, USA

    NASA Astrophysics Data System (ADS)

    Omernik, James M.; Rohm, Christina M.; Lillie, Richard A.; Mesner, Nancy

    1991-03-01

    A map of summer total phosphorus in lakes was compiled recently for a three-state area of the upper Midwest for purposes of identifying regional patterns of total phosphorus in lakes and attainable lake trophic state. Spatial patterns in total phosphorus from approximately 3000 lakes were studied in conjunction with maps of geographic characteristics that tend to affect phosphorus balance in lakes to identify regions of similarity in phosphorus concentrations in lakes or similarity in the mosaic of values as compared to adjacent areas. While degrees of relative homogeneity are apparent at many scales, the map was designed at a scale that would yield regions with sufficient homogeneity to be useful for lake management throughout the area. In this study, data from 210 lakes in a 1560-mi2 area in northwestern Wisconsin, sampled by the Wisconsin Department of Natural Resources in the spring of 1988 (subsequent to the compilation of the phosphorus map), were examined to: (1) substantiate the existence of the regions depicted on the map in northwest Wisconsin, (2) determine the nature and relative precision of the regional boundaries, (3) determine the relative importance of natural and anthropogenic watershed characteristics, lake types, lake area, and lake depth in explaining within-region differences in lake phosphorus, and (4) demonstrate how the regions might be used by local lake managers.

  8. Genetic assessment of strain-specific sources of lake trout recruitment in the Great Lakes

    USGS Publications Warehouse

    Page, Kevin S.; Scribner, Kim T.; Bennett, Kristine R.; Garzel, Laura M.; Burnham-Curtis, Mary K.

    2003-01-01

    Populations of wild lake trout Salvelinus namaycush have been extirpated from nearly all their historical habitats across the Great Lakes. Efforts to restore self-sustaining lake trout populations in U.S. waters have emphasized the stocking of coded-wire-tagged juveniles from six hatchery strains (Seneca Lake, Lewis Lake, Green Lake, Apostle Islands, Isle Royale, and Marquette) into vacant habitats. Strain-specific stocking success has historically been based on estimates of the survival and catch rates of coded-wire-tagged adults returning to spawning sites. However, traditional marking methods and estimates of relative strain abundance provide no means of assessing strain fitness (i.e., the realized contributions to natural recruitment) except by assuming that young-of-the-year production is proportional to adult spawner abundance. We used microsatellite genetic data collected from six hatchery strains with likelihood-based individual assignment tests (IA) and mixed-stock analysis (MSA) to identify the strain composition of young of the year recruited each year. We show that strain classifications based on IA and MSA were concordant and that the accuracy of both methods varied based on strain composition. Analyses of young-of-the-year lake trout samples from Little Traverse Bay (Lake Michigan) and Six Fathom Bank (Lake Huron) revealed that strain contributions differed significantly from estimates of the strain composition of adults returning to spawning reefs. The Seneca Lake strain contributed the majority of juveniles produced on Six Fathom Bank and more young of the year than expected within Little Traverse Bay. Microsatellite markers provided a method for accurately classifying the lake trout hatchery strains used for restoration efforts in the Great Lakes and for assessment of strain-specific reproductive success.

  9. Analysis of E-Inclusion Projects in Russia, Austria and Switzerland

    ERIC Educational Resources Information Center

    Niehaves, Bjorn; Plattfaut, Ralf; Gorbacheva, Elena; Vages, Peter H.

    2010-01-01

    Purpose: The issue of digital divide is widely discussed in research as well as in practice. Today, especially senior citizens are excluded from the merits of using information and communication technologies (ICT). This paper aims to study municipal projects for an inclusive information society in Russia, Austria, and Switzerland.…

  10. Use of egg traps to investigate lake trout spawning in the Great Lakes

    USGS Publications Warehouse

    Schreiner, Donald R.; Bronte, Charles R.; Payne, N. Robert; Fitzsimons, John D.; Casselman, John M.

    1995-01-01

    Disk-shaped traps were used to examine egg deposition by lake trout (Salvelinus namaycush) at 29 sites in the Great Lakes. The main objectives were to; first, evaluate the disk trap as a device for sampling lake trout eggs in the Great Lakes, and second, summarize what has been learned about lake trout spawning through the use of disk traps. Of the 5,085 traps set, 60% were classified as functional when retrieved. Evidence of lake trout egg deposition was documented in each of the lakes studied at 14 of 29 sites. A total of 1,147 eggs were trapped. The percentage of traps functioning and catch per effort were compared among sites based on depth, timing of egg deposition, distance from shore, size of reef, and type of reef (artificial or natural). Most eggs were caught on small, shallow, protected reefs that were close to shore. Use of disk traps on large, shallow, unprotected offshore reefs or along unprotected shorelines was generally unsuccessful due to the effects of heavy wind and wave action. Making multiple lifts at short intervals, and retrieval before and re-deployment after storms are recommended for use in exposed areas. On large reefs, preliminary surveys to identify preferred lake trout spawning habitat may be required to deploy disk traps most effectively. Egg deposition by hatchery-reared fish was widespread throughout the Great Lakes, and the use of artificial structures by these fish was extensive.

  11. 75 FR 34934 - Safety Zone; Fireworks for the Virginia Lake Festival, Buggs Island Lake, Clarksville, VA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-21

    ...-AA00 Safety Zone; Fireworks for the Virginia Lake Festival, Buggs Island Lake, Clarksville, VA AGENCY... Fireworks for the Virginia Lake Festival event. This action is intended to restrict vessel traffic movement... Virginia Lake Festival, Buggs Island Lake, Clarksville, VA (a) Regulated Area. The following area is a...

  12. 78 FR 53677 - Safety Zone; Battle of Lake Erie Fireworks, Lake Erie, Put-In-Bay, OH

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-30

    ...-AA00 Safety Zone; Battle of Lake Erie Fireworks, Lake Erie, Put-In- Bay, OH AGENCY: Coast Guard, DHS... waters of Lake Erie, Put-In-Bay, Ohio. This zone is intended to restrict vessels from a portion of Lake Erie during the Battle of Lake Erie Fireworks. [[Page 53678

  13. Prevalence of carbapenem-resistant Acinetobacter baumannii from 2005 to 2016 in Switzerland.

    PubMed

    Ramette, A; Kronenberg, A

    2018-04-03

    We describe the prevalence of invasive carbapenem-resistant Acinetobacter spp. isolated from 2005 to 2016 in different regions of Switzerland. Using the Swiss Antibiotic Resistance Centre (anresis) database that includes data from 70% of all hospitalized patients and one third of all ambulatory practitioners in Switzerland, we analysed the number of carbapenem-susceptible and resistant Acinetobacter spp. isolated from blood or cerebrospinal fluid, and further described their temporal and regional fluctuations. From 2005 to 2016, 58 cases of resistant or intermediate strains to carbapenem were observed among 632 cases of invasive Acinetobacter. Multivariable analyses indicated that the number of carbapenem-resistant isolates (mean 4.8 ± sd 2.12) and carbapenem resistance rates per region per annum (8.4% ± 13.9%) were low and stable over the studied period. Large fluctuations were observed at the regional level, with e.g. the North East region displaying resistance rates twice as high as that found in other regions. Despite a relatively stable number of carbapenem-resistant Acinetobacter isolates in Switzerland, our results suggest the existence of a diverse pool of A. baumannii species in hospital settings, and confirm the implication of carbapenem-resistant Acinetobacter calcoaceticus-Acinetobacter baumannii (ACB) complex in the vast majority of clinical infections and nosocomial outbreaks with notable regional fluctuations.

  14. Africa's Great Lakes in peril

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ryan, J.C.

    Three of the great lakes in East Africa are in serious danger. Over the last two decades, overfishing, pollution, and the introduction of the Nile perch, have combined to push into extinction as many as 200 fish species found in Lake Victoria. The recycling of nutrients and oxygen through living and non-living matter has been disrupted and large area of the lake are now depleted of oxygen. Overfishing has had dramatic consequences in Lake Malawi, while Lake Tanganyika's most serious problem is with sedimentation from raw sewage, soil and chemicals. International cooperation will be required to restore these lakes.

  15. PCR detection of Anaplasma phagocytophilum in goat flocks in an area endemic for tick-borne fever in Switzerland.

    PubMed

    Silaghi, C; Scheuerle, M C; Friche Passos, L M; Thiel, C; Pfister, K

    2011-02-01

    Central Switzerland is a highly endemic region for tick-borne fever (TBF) in cattle, however, little is known about A. phagocytophilum in goats. In the present study, 72 animals from six goat flocks (373 EDTA blood-samples) in Central Switzerland were analysed for A. phagocytophilum DNA. A real-time PCR targeting the msp2 gene of A. phagocytophilum was performed and in positive samples the partial 165 rRNA, groEL and msp4 gene were amplified for sequence analysis. Four DNA extracts were positive. Different sequence types on basis of the amplified genes were found. For comparison, sequences of A. phagocytophilum from 12 cattle (originating from Switzerland and Southern Germany) were analysed. The 165 rRNA gene sequences from cattle were all identical amongst each other, but the groEL and msp4 gene differed depending on the origin of the cattle samples and differed from the variants from goats. This study clearly provides molecular evidence for the presence of different types of A. phagocytophilum in goat flocks in Switzerland, a fact which deserves more thorough attention in clinical studies.

  16. 33 CFR 162.132 - Connecting waters from Lake Huron to Lake Erie; communications rules.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... monitor: (1) Channel 11 (156.55 mhz) between Lake Huron Cut Lighted Buoy 11 and Lake St. Clair Light; and (2) Channel 12 (156.60 mhz) between Lake St. Clair Light and Detroit River Light. (b) Radiotelephone... Cut Light “7” Lake Huron Cut Lighted Buoy “1” Report. Report St. Clair/Black River Junction Light...

  17. RAINBOW LAKE WILDERNESS AND FLYNN LAKE WILDERNESS STUDY AREA, WISCONSIN.

    USGS Publications Warehouse

    Cannon, W.F.; Dunn, Maynard L.

    1984-01-01

    The Rainbow Lake Wilderness and Flynn Lake Wilderness study area in Wisconsin are contiguous and were studied as a unit. The rainbow Lake Wilderness contains a demonstrated resource of about 210,000 tons of commercial-quality peat in an area of substantiated peat resource potential. The Flynn Lake Wilderness study area contains a demonstrated resource of about 300,000 tons of commercial-quality peat in an area of substantiated peat resource potential. These deposits, however, are of limited importance because larger deposits of similar material are abundant outside the areas, closer to present markets. Rocks in the subsurface contain a low-grade copper resource identified by mining company exploration drilling. Although this is an area of substantiated copper resource potential, it is a low-grade resource, thin and generally at great depth.

  18. Interoperability prototype between hospitals and general practitioners in Switzerland.

    PubMed

    Alves, Bruno; Müller, Henning; Schumacher, Michael; Godel, David; Abu Khaled, Omar

    2010-01-01

    Interoperability in data exchange has the potential to improve the care processes and decrease costs of the health care system. Many countries have related eHealth initiatives in preparation or already implemented. In this area, Switzerland has yet to catch up. Its health system is fragmented, because of the federated nature of cantons. It is thus more difficult to coordinate efforts between the existing healthcare actors. In the Medicoordination project a pragmatic approach was selected: integrating several partners in healthcare on a regional scale in French speaking Switzerland. In parallel with the Swiss eHealth strategy, currently being elaborated by the Swiss confederation, particularly medium-sized hospitals and general practitioners were targeted in Medicoordination to implement concrete scenarios of information exchange between hospitals and general practitioners with a high added value. In this paper we focus our attention on a prototype implementation of one chosen scenario: the discharge summary. Although simple in concept, exchanging release letters shows small, hidden difficulties due to the multi-partner nature of the project. The added value of such a prototype is potentially high and it is now important to show that interoperability can work in practice.

  19. Egg thiamine status of Lake Ontario salmonines 1995-2004 with emphasis on lake trout

    USGS Publications Warehouse

    Fitzsimons, J.D.; Williston, B.; Williston, G.; Brown, L.; El-Shaarawi, A.; Vandenbyllaardt, L.; Honeyfeld, D.; Tillitt, D.; Wolgamood, M.; Brown, S.B.

    2007-01-01

    Alewives (Alosa pseudoharengus), the major prey fish for Lake Ontario, contain thiaminase. They are associated with development of a thiamine deficiency in salmonines which greatly increases the potential for developing an early mortality syndrome (EMS). To assess the possible effects of thiamine deficiency on salmonine reproduction we measured egg thiamine concentrations for five species of Lake Ontario salmonines. From this we estimated the proportion of families susceptible to EMS based on whether they were below the ED20, the egg thiamine concentration associated with 20% mortality due to EMS. The ED20s were 1.52, 2.63, and 2.99 nmol/g egg for Chinook salmon (Oncorhynchus tshawytscha), lake trout (Salvelinus namaycush), and coho salmon (Oncorhynchus kisutch), respectively. Based on the proportion of fish having egg thiamine concentrations falling below the ED20, the risk of developing EMS in Lake Ontario was highest for lake trout, followed by coho (O. kisutch), and Chinook salmon, with the least risk for rainbow trout (O. mykiss). For lake trout from western Lake Ontario, mean egg thiamine concentration showed significant annual variability during 1994 to 2003, when the proportion of lake trout at risk of developing EMS based on ED20 ranged between 77 and 100%. Variation in the annual mean egg thiamine concentration for western Lake Ontario lake trout was positively related (p < 0.001, r2 = 0.94) with indices of annual adult alewife biomass. While suggesting the possible involvement of density-dependent changes in alewives, the changes are small relative to egg thiamine concentrations when alewife are not part of the diet and are of insufficient magnitude to allow for natural reproduction by lake trout.

  20. Lake Generated Microseisms at Yellowstone Lake as a Record of Ice Phenology

    NASA Astrophysics Data System (ADS)

    Mohd Mokhdhari, A. A.; Koper, K. D.; Burlacu, R.

    2017-12-01

    It has recently been shown that wave action in lakes produces microseisms, which generate noise peaks in the period range of 0.8-1.2 s as recorded by nearby seismic stations. Such noise peaks have been observed at seven seismic stations (H17A, LKWY, B208, B944, YTP, YLA, and YLT) located within 2 km of the Yellowstone Lake shoreline. Initial work using 2016 data shows that the variations in the microseism signals at Yellowstone Lake correspond with the freezing and thawing of lake ice: the seismic noise occurs more frequently in the spring, summer, and fall, and less commonly in the winter. If this can be confirmed, then lake-generated microseisms could provide a consistent measure of the freezing and melting dates of high-latitude lakes in remote areas. The seismic data would then be useful in assessing the effects of climate change on the ice phenology of those lakes. In this work, we analyze continuous seismic data recorded by the seven seismic stations around Yellowstone Lake for the years of 1995 to 2016. We generate probability distribution functions of power spectral density for each station to observe the broad elevation of energy near a period of 1 s. The time dependence of this 1-s seismic noise energy is analyzed by extracting the power spectral density at 1 s from every processed hour. The seismic observations are compared to direct measurements of the dates of ice-out and freeze-up as reported by rangers at Yellowstone National Park. We examine how accurate the seismic data are in recording the freezing and melting of Yellowstone Lake, and how the accuracy changes as a function of the number of stations used. We also examine how sensitive the results are to the particular range of periods that are analyzed.

  1. Characterization and comparison of phytoplankton in selected lakes of five Great Lakes area national parks

    USGS Publications Warehouse

    Nevers, Meredith Becker; Whitman, Richard L.

    2004-01-01

    Phytoplankton species have been widely used as indicators of lake conditions, and they may be useful for detecting changes in overall lake condition. In an attempt to inventory and monitor its natural resources, the National Park Service wants to establish a monitoring program for aquatic resources in the Great Lakes Cluster National Parks. This study sought to establish baseline information on the phytoplankton and water chemistry of selected lakes in five national parks in a preliminary effort toward establishing a long-term monitoring program. Phytoplankton and water chemistry samples were collected from ten lakes in five national parks over a two-year period. A total of 176 taxa were identified during the study. Northern lakes generally had higher Shannon-Wiener diversity and clustered together in similarity. Lakes exhibited a south to north gradient of many water chemistry variables, with northern lakes having lower hardness, sulfate, turbidity, and temperature and higher dissolved oxygen. Chloride and sulfate concentrations were the variables that best explained variation among phytoplankton in the ten lakes. A monitoring plan will have to incorporate the differences among lakes, but by coordinating the effort, comparisons within and among parks and other regions will prove useful for determining environmental change.

  2. Monitoring climate signal transfer into the varved lake sediments of Lake Czechowskie, Poland

    NASA Astrophysics Data System (ADS)

    Groß-Schmölders, Miriam; Ott, Florian; Brykała, Dariusz; Gierszewski, Piotr; Kaszubski, Michał; Kienel, Ulrike; Brauer, Achim

    2015-04-01

    In 2012 we started a monitoring program at Lake Czechowskie, Poland, because the lake comprises a long Holocene time series of calcite varves until recent times. The aim of the program is to understand how environmental and climatic conditions influence the hydrological conditions and, ultimately, the sediment deposition processes of the lake. Lake Czechowskie is located in the north of Poland in the Pomeranian Lake District and is part of the national park Tuchola Forest. The landscape and the lake is formed by the glacier retreat after the last glaciation (Weichselian). Lake Czechowskie is a typical hardwater lake and has a length of 1.4 km, an average width of 600 m and a lake surface area of ca 4 km. The maximum depth of 32 m is reached in a rather small hollow in the eastern part of the lake. Two different types of sediment traps provide sediment samples with monthly resolution from different water depths (12m, 26m). In addition, hydrological data including water temperature in different depths, water inflow, throughflow and outflow and the depth of visibility are measured. These data allow to describe strength and duration of lake mixing in spring and autumn and its influence on sedimentation. The sediment samples were analyzed with respect to their dry weight (used to calculate mean daily sediment flux), their inorganic and organic carbon contents, the stable C- and O-isotopes of organic matter and calcite as well as N-isotopes of organic matter. For selected samples dominant diatom taxa are determined. Our first results demonstrate the strong influence of the long winter with ice cover until April in 2013 on the sedimentation. A rapid warming in only 9 days starting on April 9th from -0,3 C° to 15,2 C° resulted in fast ice break-up and a short but intensive lake mixing. In consequence of this short mixing period a strong algal bloom especially of Fragilaria and Crysophycea commenced in April and had its maximum in May. This bloom further induced biogenic

  3. Salinity and hydrology of closed lakes

    USGS Publications Warehouse

    Langbein, Walter Basil

    1961-01-01

    Lakes without outlets, called closed lakes, are exclusively features of the arid and semiarid zones where annual evaporation exceeds rainfall. The number of closed lakes increases with aridity, so there are relatively few perennial closed lakes, but "dry" lakes that rarely contain water are numerous.Closed lakes fluctuate in level to a much greater degree than the open lakes of the humid zone, because variations in inflow can be compensated only by changes in surface area. Since the variability of inflow increases with aridity, it is possible to derive an approximate relationship for the coefficient of variation of lake area in terms of data on rates of evaporation, lake area, lake depth, and drainage area.The salinity of closed lakes is highly variable, ranging from less than 1 percent to over 25 percent by weight of salts. Some evidence suggests that the tonnage of salts in a lake solution is substantially less than the total input of salts into the lake over the period of existence of the closed lake. This evidence suggests further that the salts in a lake solution represent a kind of long-term balance between factors of gain and loss of salts from the solution.Possible mechanisms for the loss of salts dissolved in the lake include deposition in marginal bays, entrapment in sediments, and removal by wind. Transport of salt from the lake surface in wind spray is also a contributing, but seemingly not major, factor.The hypothesis of a long-term balance between input to and losses from the lake solution is checked by deriving a formula for the equilibrium concentration and comparing the results with the salinity data. The results indicate that the reported salinities seemingly can be explained in terms of their geometric properties and hydrologic environment.The time for accumulation of salts in the lake solution the ratio between mass of salts in the solution and the annual input may also be estimated from the geometric and hydrologic factors, in the absence of

  4. Crater Lake revealed

    USGS Publications Warehouse

    Ramsey, David W.; Dartnell, Peter; Bacon, Charles R.; Robinson, Joel E.; Gardner, James V.

    2003-01-01

    Around 500,000 people each year visit Crater Lake National Park in the Cascade Range of southern Oregon. Volcanic peaks, evergreen forests, and Crater Lake’s incredibly blue water are the park’s main attractions. Crater Lake partially fills the caldera that formed approximately 7,700 years ago by the eruption and subsequent collapse of a 12,000-foot volcano called Mount Mazama. The caldera-forming or climactic eruption of Mount Mazama drastically changed the landscape all around the volcano and spread a blanket of volcanic ash at least as far away as southern Canada.Prior to the climactic event, Mount Mazama had a 400,000 year history of cone building activity like that of other Cascade volcanoes such as Mount Shasta. Since the climactic eruption, there have been several less violent, smaller postcaldera eruptions within the caldera itself. However, relatively little was known about the specifics of these eruptions because their products were obscured beneath Crater Lake’s surface. As the Crater Lake region is still potentially volcanically active, understanding past eruptive events is important to understanding future eruptions, which could threaten facilities and people at Crater Lake National Park and the major transportation corridor east of the Cascades.Recently, the lake bottom was mapped with a high-resolution multibeam echo sounder. The new bathymetric survey provides a 2m/pixel view of the lake floor from its deepest basins virtually to the shoreline. Using Geographic Information Systems (GIS) applications, the bathymetry data can be visualized and analyzed to shed light on the geology, geomorphology, and geologic history of Crater Lake.

  5. Lake Sarez, Tajikistan

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Lake Sarez (top), deep in the Pamir mountains of Tajikistan, was created 90 years ago when a strong earthquake triggered a massive landslide that, in turn, became a huge dam along the Murghob River, now called the Usoi Dam. The resulting lake is perched above surrounding drainages at an elevation greater than 3000m, and is part of the watershed that drains the towering Akademi Nauk Range (see the regional image, lower). The lake is 61 km long and as deep as 500 m, and holds an estimated 17 cubic km of water. The area experiences considerable seismic activity, and scientists fear that part of the right bank may slump into the lake, creating a huge wave that will top over and possibly breach the natural dam. Such a wave would create a catastrophic flood downstream along the Bartang, Panj and Amu Darya Rivers, perhaps reaching all the way to the Aral Sea. Currently, central Asian governments, as well as the World Bank and the UN are monitoring the dam closely, and have proposed gradually lowering the lake level as a preventive measure. More information about the lake is available at the following web sites: Lake Sarez Study group, UN Report, Reliefweb Digital photograph numbers ISS002-E-7771 and ISS002-E-7479 were taken in the spring of 2001 from Space Station Alpha and are provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth.

  6. Aletsch Glacier, Switzerland

    NASA Image and Video Library

    2002-09-03

    Aletsch Glacier, the largest glacier of Europe, covers more than 120 square kilometers (more than 45 square miles) in southern Switzerland. At its eastern extremity lies a glacierlake, Mdrjelensee (2,350 meters/7,711 feet above sea level). To the west rises Aletschhorn (4,195 meters/13,763 feet), which was first climbed in 1859. The Rhone River flows along the southern flank of the mountains. This image was acquired on July 23, 2001 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image Earth for the next 6 years to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. http://photojournal.jpl.nasa.gov/catalog/PIA03857

  7. ATMOSPHERIC MERCURY DEPOSITION TO LAKE MICHIGAN DURING THE LAKE MICHIGAN MASS BALANCE STUDY

    EPA Science Inventory

    Wet and dry mercury (Hg) deposition were calculated to Lake Michigan using a hybrid receptor modeling framework. The model utilized mercury monitoring data collected during the Lake Michigan Mass Balance Study and the Atmospheric Exchange Over Lakes and Oceans Study together w...

  8. The Great Lakes' regional climate regimes

    NASA Astrophysics Data System (ADS)

    Sugiyama, Noriyuki

    For the last couple of decades, the Great Lakes have undergone rapid surface warming. In particular, the magnitude of the summer surface-warming trends of the Great Lakes have been much greater than those of surrounding land (Austin and Colman, 2007). Among the Great Lakes, the deepest Lake Superior exhibited the strongest warming trend in its annual, as well as summer surface water temperature. We find that many aspects of this behavior can be explained in terms of the tendency of deep lakes to exhibit multiple regimes characterized, under the same seasonally varying forcing, by the warmer and colder seasonal cycles exhibiting different amounts of wintertime lake-ice cover and corresponding changes in the summertime lake-surface temperatures. In this thesis, we address the problem of the Great Lakes' warming using one-dimensional lake modeling to interpret diverse observations of the recent lake behavior. (Abstract shortened by ProQuest.).

  9. Characterization of lake water and ground water movement in the littoral zone of Williams Lake, a closed-basin lake in North central Minnesota

    USGS Publications Warehouse

    Schuster, P.F.; Reddy, M.M.; LaBaugh, J.W.; Parkhurst, R.S.; Rosenberry, D.O.; Winter, T.C.; Antweiler, Ronald C.; Dean, W.E.

    2003-01-01

    Williams Lake, Minnesota is a closed-basin lake that is a flow-through system with respect to ground water. Ground-water input represents half of the annual water input and most of the chemical input to the lake. Chemical budgets indicate that the lake is a sink for calcium, yet surficial sediments contain little calcium carbonate. Sediment pore-water samplers (peepers) were used to characterize solute fluxes at the lake-water-ground-water interface in the littoral zone and resolve the apparent disparity between the chemical budget and sediment data. Pore-water depth profiles of the stable isotopes ??18O and ??2H were non-linear where ground water seeped into the lake, with a sharp transition from lake-water values to ground-water values in the top 10 cm of sediment. These data indicate that advective inflow to the lake is the primary mechanism for solute flux from ground water. Linear interstitial velocities determined from ??2H profiles (316 to 528 cm/yr) were consistent with velocities determined independently from water budget data and sediment porosity (366 cm/yr). Stable isotope profiles were generally linear where water flowed out of the lake into ground water. However, calcium profiles were not linear in the same area and varied in response to input of calcium carbonate from the littoral zone and subsequent dissolution. The comparison of pore-water calcium profiles to pore-water stable isotope profiles indicate calcium is not conservative. Based on the previous understanding that 40-50 % of the calcium in Williams Lake is retained, the pore-water profiles indicate aquatic plants in the littoral zone are recycling the retained portion of calcium. The difference between the pore-water depth profiles of calcium and ??18O and ??2H demonstrate the importance of using stable isotopes to evaluate flow direction and source through the lake-water-ground-water interface and evaluate mechanisms controlling the chemical balance of lakes. Published in 2003 by John Wiley

  10. LakeVOC; A Deterministic Model to Estimate Volatile Organic Compound Concentrations in Reservoirs and Lakes

    USGS Publications Warehouse

    Bender, David A.; Asher, William E.; Zogorski, John S.

    2003-01-01

    This report documents LakeVOC, a model to estimate volatile organic compound (VOC) concentrations in lakes and reservoirs. LakeVOC represents the lake or reservoir as a two-layer system and estimates VOC concentrations in both the epilimnion and hypolimnion. The air-water flux of a VOC is characterized in LakeVOC in terms of the two-film model of air-water exchange. LakeVOC solves the system of coupled differential equations for the VOC concentration in the epilimnion, the VOC concentration in the hypolimnion, the total mass of the VOC in the lake, the volume of the epilimnion, and the volume of the hypolimnion. A series of nine simulations were conducted to verify LakeVOC representation of mixing, dilution, and gas exchange characteristics in a hypothetical lake, and two additional estimates of lake volume and MTBE concentrations were done in an actual reservoir under environmental conditions. These 11 simulations showed that LakeVOC correctly handled mixing, dilution, and gas exchange. The model also adequately estimated VOC concentrations within the epilimnion in an actual reservoir with daily input parameters. As the parameter-input time scale increased (from daily to weekly to monthly, for example), the differences between the measured-averaged concentrations and the model-estimated concentrations generally increased, especially for the hypolimnion. This may be because as the time scale is increased from daily to weekly to monthly, the averaging of model inputs may cause a loss of detail in the model estimates.

  11. Multi-disciplinary study for the exploration of deep low enthalpy geothermal reservoirs, Neuchâtel, Switzerland

    NASA Astrophysics Data System (ADS)

    Mauri, G.; Abdelfettah, Y.; Negro, F.; Schill, E.; Vuataz, F.

    2011-12-01

    The authorities of the canton of Neuchâtel, in the Western part of Switzerland, are willing to develop geothermal energy for district heating in the two main cities of the canton: Neuchâtel, located along the Lake of Neuchâtel, and La Chaux-de-Fonds situated in a high valley of the Jura Massif. The geology of both areas is linked to the Jura Range and present complex structures, where the landscape is composed of anticlines associated with overthrust faults, which are overcut by strike-slip fault and secondary faulting events. The rock formations go from the Trias, which forms the detachment layer, up to the Quaternary rock. Bedrocks are mainly composed of limestones and marls, which can reach a thickness of several hundreds meters. The three main deep aquifers investigated in this area, from the shallowest (≤ 400 m below surface) to deepest (< 2000 m), are the Malm, the Dogger and the Muschelkalk. The estimated temperatures, based on previous studies, should range between 20 to 65 oC, which are function of depth, elevation and groundwater velocity. The expected low temperature is mainly due to the presence of karstic systems, which drains the heat towards the low elevation of the basin. The present study is based on gravimetry surveys, 3D geological models and 3D gravimetry models to best characterize the underground structures and to find areas where the rock properties would be favourable to geothermal exploitation. This means targets where permeability and porosity are high in the potential aquifers, allowing a significant flow at the future production wells. The results indicate that gravity anomalies are associated with both shallow and deep geological structures in the two exploration sites and that high resolution of dense grid gravity measurements combined with realistic 3D models of the geological structures allow to characterize interesting features for deep geothermal exploration. Gravity corrections were carried out with a computing code using

  12. Is Lake Chabot Eutrophic?

    NASA Astrophysics Data System (ADS)

    Pellegrini, K.; Logan, J.; Esterlis, P.; Lew, A.; Nguyen, M.

    2013-12-01

    Introduction/Abstract: Lake Chabot is an integral part of the East Bay watershed that provides habitats for animals and recreation for humans year-round. Lake Chabot has been in danger of eutrophication due to excessive dumping of phosphorous and nitrogen into the water from the fertilizers of nearby golf courses and neighboring houses. If the lake turned out to be eutrophified, it could seriously impact what is currently the standby emergency water supply for many Castro Valley residents. Eutrophication is the excessive richness of nutrients such as nitrogen and phosphorus in a lake, usually as a result of runoff. This buildup of nutrients causes algal blooms. The algae uses up most of the oxygen in the water, and when it dies, it causes the lake to hypoxify. The fish in the lake can't breathe, and consequently suffocate. Other oxygen-dependant aquatic creatures die off as well. Needless to say, the eutrophication of a lake is bad news for the wildlife that lives in or around it. The level of eutrophication in our area in Northern California tends to increase during the late spring/early summer months, so our crew went out and took samples of Lake Chabot on June 2. We focused on the area of the lake where the water enters, known on the map as Honker Bay. We also took readings a ways down in deeper water for comparison's sake. Visually, the lake looked in bad shape. The water was a murky green that glimmered with particulate matter that swirled around the boat as we went by. In the Honker Bay region where we focused our testing, there were reeds bathed in algae that coated the surface of the lake in thick, swirling patterns. Surprisingly enough, however, our test results didn't reveal any extreme levels of phosphorous or nitrogen. They were slightly higher than usual, but not by any significant amount. The levels we found were high enough to stimulate plant and algae growth and promote eutrophication, but not enough to do any severe damage. After a briefing with a

  13. Cooperative science to inform Lake Ontario management: Research from the 2013 Lake Ontario CSMI program

    USGS Publications Warehouse

    Watkins, James M.; Weidel, Brian C.; Fisk, Aaron T.; Rudstam, Lars G.

    2017-01-01

    Since the mid-1970s, successful Lake Ontario management actions including nutrient load and pollution reductions, habitat restoration, and fish stocking have improved Lake Ontario. However, several new obstacles to maintenance and restoration have emerged. This special issue presents management-relevant research from multiple agency surveys in 2011 and 2012 and the 2013 Cooperative Science and Monitoring Initiative (CSMI), that span diverse lake habitats, species, and trophic levels. This research focused on themes of nutrient loading and fate; vertical dynamics of primary and secondary production; fish abundance and behavior; and food web structure. Together these papers identify the status of many of the key drivers of the Lake Ontario ecosystem and contribute to addressing lake-scale questions and management information needs in Lake Ontario and the other Great Lakes and connecting water bodies.

  14. Hydrology of the Reelfoot Lake basin, Obion and Lake counties, northwestern Tennessee

    USGS Publications Warehouse

    Robbins, C.H.

    1985-01-01

    Nine maps describe the following water resources aspects of the Reelfoot Lake watershed: Map 1-Surface water gaging stations, lake level, and locations of observation wells, rainfall stations and National Weather Service rainfall stations; Maps 2 and 3-water level contours, river stage, groundwater movement; Maps 4 and 5-grid blocks simulating constant head on the Mississippi River, Reelfoot Lake, Running Reelfoot Bayou, Reelfoot Creek, and Running Slough; Maps 6 and 7-difference between model calculated and observed water levels; and Maps 8 and 9-line of equal groundwater level increase and approximate lake area at pool elevation. (Lantz-PTT)

  15. Dendrochronology and lakes: using tree-rings of alder to reconstruct lake levels

    NASA Astrophysics Data System (ADS)

    van der Maaten, Ernst; Buras, Allan; Scharnweber, Tobias; Simard, Sonia; Kaiser, Knut; Lorenz, Sebastian; van der Maaten-Theunissen, Marieke; Wilmking, Martin

    2014-05-01

    Climate change is considered a major threat for ecosystems around the world. Assessing its effects is challenging, amongst others, as we are unsure how ecosystems may respond to climate conditions they were not exposed to before. However, increased insight may be obtained by analyzing responses of ecosystems to past climate variability. In this respect, lake ecosystems appear as valuable sentinels, because they provide direct and indirect indicators of change through effects of climate. Lake-level fluctuations of closed catchments, for example, reflect a dynamic water balance, provide detailed insight in past moisture variations, and thereby allow for assessments of effects of anticipated climate change. Up to now, lake-level data are mostly obtained from gauging records and reconstructions from sediments and landforms. However, these records are in many cases only available over relatively short time periods, and, since geoscientific work is highly demanding, lake-level reconstructions are lacking for many regions. Here, we present and discuss an alternative method to reconstruct lake levels, which is based on tree-ring data of black alder (Alnus glutinosa L.). This tree species tolerates permanently waterlogged and temporally flooded conditions (i.e. riparian vegetation), and is often found along lakeshores. As the yearly growth of trees varies depending upon the experienced environmental conditions, annual rings of black alder from lakeshore vegetation likely capture information on variations in water table, and may therefore be used to reconstruct lake levels. Although alder is a relatively short-lived tree species, the frequent use of its' decay-resistant wood in foundations of historical buildings offers the possibility of extending living tree-chronologies back in time for several centuries. In this study, the potential to reconstruct lake-level fluctuations from tree-ring chronologies of black alder is explored for three lake ecosystems in the Mecklenburg

  16. Comparative Intergroup Relations and Social Incorporation in Two Multilingual Societies: Canada and Switzerland. Occasional Paper No. 95-03.1.

    ERIC Educational Resources Information Center

    Schmid, Carol

    A study of national identity and social integration in two multilingual societies, Canada and Switzerland, examines the relations between Quebec and anglophone Canada and between French and German Switzerland. First, the historical setting for the emergence of multilingualism is outlined for both countries, and the demography of the major language…

  17. Towards the new CH2018 climate scenarios for Switzerland

    NASA Astrophysics Data System (ADS)

    Fischer, Andreas; Schär, Christoph; Croci-Maspoli, Mischa; Knutti, Reto; Liniger, Mark; Strassmann, Kuno

    2017-04-01

    There is a growing demand for regional assessments of future climate change and its impacts on society and ecosystems to inform and facilitate appropriate adaptation strategies. The basis for such assessments are consistent and up-to-date climate change scenarios on the local to regional scale. In Switzerland, an important step has been accomplished by the release of the climate scenarios in 2011 ("CH2011"). Since then, new climate model simulations have become available and the scientific understanding has improved. It is hence desirable to update these national scenarios. The new CH2018 scenarios are developed in the framework of the recently founded National Center for Climate Services (NCCS), a network consisting of several federal offices and academic partners. The CH2018 scenarios will build primarily upon the latest Euro-CORDEX regional climate model simulations assuming different pathways of future greenhouse gas concentrations. Compared to CH2011, more emphasis will be put on changes in extremes and in putting the projected changes in the context of observed variability. Results of a recently conducted survey on end-user needs in Switzerland will guide the development process toward the CH2018 scenarios. It ensures that the scenarios are presented and communicated in a user-oriented format and find a wide applicability across different sectors in Switzerland. In the presentation we will show the full methodological setup to generate the CH2018 scenarios and how consistency across the methods and products is maximized. First results on mean changes and selected indices will be presented. In terms of dissemination, the results of the user survey show the necessity to address all different user types of climate scenarios, especially the non-experts. Compared to CH2011, this implies a stronger focus on consulting, condensing complex information and providing tutorials. In the presentation, we will outline our plans on dissemination in order to adequately

  18. Sexual difference in PCB concentrations of lake trout (Salvelinus namaycush) from Lake Ontario

    USGS Publications Warehouse

    Madenjian, Charles P.; Keir, Michael J.; Whittle, D. Michael; Noguchi, George E.

    2010-01-01

    We determined polychlorinated biphenyl (PCB) concentrations in 61 female lake trout (Salvelinus namaycush) and 71 male lake trout from Lake Ontario (Ontario, Canada and New York, United States). To estimate the expected change in PCB concentration due to spawning, PCB concentrations in gonads and in somatic tissue of lake trout were also determined. In addition, bioenergetics modeling was applied to investigate whether gross growth efficiency (GGE) differed between the sexes. Results showed that, on average, males were 22% higher in PCB concentration than females in Lake Ontario. Results from the PCB determinations of the gonads and somatic tissues revealed that shedding of the gametes led to 3% and 14% increases in PCB concentration for males and females, respectively. Therefore, shedding of the gametes could not explain the higher PCB concentration in male lake trout. According to the bioenergetics modeling results, GGE of males was about 2% higher than adult female GGE, on average. Thus, bioenergetics modeling could not explain the higher PCB concentrations exhibited by the males. Nevertheless, a sexual difference in GGE remained a plausible explanation for the sexual difference in PCB concentrations of the lake trout.

  19. Historical evidence for discrete stocks of lake trout (Salvelinus namaycush) in Lake Michigan

    USGS Publications Warehouse

    Brown, Edward H.; Eck, G.W.; Foster, N.R.; Horrall, R.M.; Coberly, C.E.

    1981-01-01

    Although few biological data exist on the now extinct native lake trout, Salvelinus namaycush, of Lake Michigan, historical records and interviews with former commercial fishermen strongly suggest that this once widespread resource was composed of a number of discrete spawning populations or stocks. A natural division of the resource into distinct stocks is consistent with the size of Lake Michigan and its varied physiography. The native trout may have undergone subtle genetic changes over the millennia, although we cannot determine whether the physical and behavioral differences represented different genotypes or only temporary effects of the local environment. Because of physiographic similarities among the upper Great Lakes and probable interchanges of lake trout during the last glacial period, we recommend that progeny of extant wild stocks, particularly from Lake Superior, are genetically most suitable for recolonizing Lake Michigan. Moreover, the hatchery-held parents of such fish should be infused periodically with genes of the wild or feral donor populations. Despite the sound historical basis for these recommendations, we also recognize that sufficiently high stocking rates coupled with a reduction of heavy exploitation may be even more important than heritability in obtaining self-sustaining populations.

  20. Lake Mead, NV

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Lake Mead, Nevada, (36.0N, 114.5E) where the water from the Colorado River empties after it's 273 mile journey through the Grand Canyon of Arizona is the subject of this photo. Other features of interest are Hoover Dam on the south shore of Lake Mead where cheap hydroelectric power is secondary to the water resources made available in this northern desert region and the resort city of Las Vegas, just to the west of Lake Mead.

  1. Loktak Lake, India

    NASA Image and Video Library

    2018-04-13

    Loktak Lake is the largest freshwater lake in northeast India, and is famous for the floating "phudmis," masses of vegetation, soil and organic material. The lake is a source of water for hydropower, irrigation, drinking water, and livelihood for fish farmers. The image was acquired March 19, 2018, covers an area of 20.5 by 27.3 kilometers, and is located at 24.5 degrees north, 93.8 degrees east. https://photojournal.jpl.nasa.gov/catalog/PIA22369

  2. Can "Vocationalisation" of Education Go Too Far? The Case of Switzerland

    ERIC Educational Resources Information Center

    Meyer, Thomas

    2009-01-01

    While countries with predominantly academic school-based upper secondary education have been "discovering" vocational education and training (VET) for some time, countries with "vocationalised" education systems such as Austria, Germany or Switzerland are critically reviewing their own situations. This paper takes up the case…

  3. Authigenic carbonate precipitation in Lake Acigöl, a hypersaline lake in southwestern Turkey

    NASA Astrophysics Data System (ADS)

    Balci, Nurgul; Menekse, Meryem; Gül Karagüler, Nevin; Seref Sönmez, M.; Meister, Patrick

    2014-05-01

    Lake Acigöl (Bitter Lake) is a hypersaline lake in southwestern Turkey at an elevation of 836 m above sea level showing authigenic precipitation of several different carbonate mineral phases. It is a perennial lake and closed drainage basin where a semiarid continental climate dominates. Due to the extreme water chemistry (salinity 8-200 mg/l; SO4 112-15232 mg/l; Cl 290-35320 mg/l; Mg, 82-3425 mg/l; Ca 102-745 mg/l) unique microorganisms flourish in the lake. We studied microbial diversity from enrichment cultures and performed precipitation experiments using similar water chemistry and adding bacterial enrichment cultures from lake sediments in order to elucidate whether the mineral assemblages found in the lake can be reproduced. Experiments using moderately halophilic bacteria obtained from the lake sediments demonstrate the formation of various calcium-/magnesium-carbonates: hydromagnesite, dypingite, huntite, monohydrocalcite and aragonite. The relative amounts of different mineral phases, particularly monohydrocalcite, hydromagnesite and dypingite, could be controlled by varying the sulphate concentration in the media from 0 to 56 mM. The similar mineral assemblages identified in the sediments of Lake Acigöl and in the experiments point to similar thermodynamic conditions and kinetics of crystal growth. In particular, the similar spherical morphology points to a rapid crystal growth under strong kinetic inhibition, possibly by organic polymers that are commonly produced by microbial communities. Our results demonstrate that the authigenic carbonate paragenesis of hypersaline lakes as Lake Acigöl can be reproduced in halophilic bacterial cultures. The exact thermodynamic conditions and precipitation kinetics under seasonally changing water chemistry or in batch experiment, however, still have to be constrained in order to establish a microbial model for carbonate precipitation in such environments.

  4. Glacial Lake Lind, Wisconsin and Minnesota

    USGS Publications Warehouse

    Johnson, M.D.; Addis, K.L.; Ferber, L.R.; Hemstad, C.B.; Meyer, G.N.; Komai, L.T.

    1999-01-01

    Glacial Lake Lind developed in the pre-late Wisconsinan St. Croix River valley, Minnesota and Wisconsin, and lasted more than 1000 yr during the retreat of the Superior lobe at the end of the Wisconsinan glaciation. Lake Lind sediment consists primarily of red varved silt and clay, but also includes mud-flow deposits, nearshore silt (penecontemporaneously deformed in places), nearshore rippled sand, and deltaic sand. Lake Lind varved red clay is not part of glacial Lake Grantsburg, as suggested by earlier authors, because the red varves are separated from overlying glacial Lake Grantsburg silt and clay by a unit of deltaic and fluvial sand. Furthermore, varve correlations indicate that the base of the red varves is younger to the north, showing that the basin expanded as the Superior lobe retreated and was not a lake basin dammed to the southwest by the advancing Grantsburg sublobe. Varve correlations indicate that the Superior lobe retreated at a rate of about 200 m/yr. Uniform winter-clay thickness throughout most of the varve couplets suggests thermal stratification in the lake with clay trapped in the epilimnion; some clay would exit the lake at the outlet prior to winter freeze. Zones of thicker winter-clay layers, in places associated with mud-flow layers, indicate outlet incision, lake-level fall, and shoreline erosion and resuspension of lake clay. The most likely outlet for glacial Lake Lind was in the southwest part of the lake near the present site of Minneapolis, Minnesota. Nearshore sediment indicates that the lake level of glacial Lake Lind was around 280 m. The elevation of the base of the Lake Lind sediments indicates water depth was 20 to 55 m. Evidence in the southern part of the lake basin suggests that the Superior lobe readvanced at least once during the early stages of glacial Lake Lind. Lake Lind ended not by drainage but by being filled in by prograding deltas and outwash plains composed of sand derived from the retreating Superior lobe. It

  5. Isotope analyses of the lake sediments in the Plitvice Lakes, Croatia

    NASA Astrophysics Data System (ADS)

    Horvatinčić, Nada; Sironić, Andreja; Barešić, Jadranka; Bronić, Ines Krajcar; Nikolov, Jovana; Todorović, Nataša; Hansman, Jan; Krmar, Miodrag

    2014-10-01

    The analyses of radioactive isotopes 14C, 137Cs and 210Pb, and stable isotope 13C were performed in the sediment cores, top 40 cm, taken in 2011 from karst lakes Prošće and Kozjak in the Plitvice Lakes National Park, central Croatia. Frozen sediment cores were cut into 1 cm thick layers and dried. 14C activity in both carbonate and organic fractions was measured using accelerator mass spectrometry technique with graphite synthesis. 137Cs, 210Pb, 214Pb and 214Bi were measured by low level gamma spectrometry method on ORTECHPGe detector with the efficiency of 32%. Distribution of 14C activity from both lakes showed increase of the 14C activity in the top 10-12 cm in both carbonate and organic fractions as a response to thermonuclear bomb-produced 14C in the atmosphere in the sixties of the 20th century. Anthropogenically produced 137Cs was also observed in sediment profiles. Sedimentation rates for both lake sediments were estimated based on the unsupported 210Pb activity. Different 14C activity of the carbonate fraction (63-80 pMC, percent of modern carbon) and organic fraction (82-93 pMC) is the result of geochemical and biological processes of the sediment precipitation in the lake waters. This is also confirmed by the δ 13 C values of both fractions. Carbon isotope composition, a 14 C and δ 13 C, was compared with the lake sediments from the same lakes collected in 1989 and 2003.

  6. Changes in bathymetry for Lake Katherine and Wood Lake, Richland County, South Carolina, 1989-93

    USGS Publications Warehouse

    Patterson, Glenn G.

    1995-01-01

    Bathymetric surveys of Lake Katherine and Wood Lake, small residential lakes in Columbia, South Carolina, were made in 1989 and 1993. During this period the combined volume of the lakes decreased by 519,000 cubic feet (11.9 acre-feet). Most of the decrease in volume occurred in the northern part of Lake Katherine where deltaic sediment deposits at the mouth of Gills Creek increased in thickness during the 4-year period. The sediment was derived from a combination of sources in the Gills Creek Basin upstream from the lakes. Construction of a highway and a housing development in the Basin were significant factors in the sedimentation.

  7. Hydrochemical determination of source water contributions to Lake Lungo and Lake Ripasottile (central Italy)

    USGS Publications Warehouse

    Archer, Claire; Noble, Paula; Kreamer, David; Piscopo, Vincenzo; Petitta, Marco; Rosen, Michael R.; Poulson, Simon R.; Piovesan, Gianluca; Mensing, Scott

    2017-01-01

    Lake Lungo and Lake Ripasottile are two shallow (4-5 m) lakes located in the Rieti Basin, central Italy, that have been described previously as surface outcroppings of the groundwater table. In this work, the two lakes as well as springs and rivers that represent their potential source waters are characterized physio-chemically and isotopically, using a combination of environmental tracers. Temperature and pH were measured and water samples were analyzed for alkalinity, major ion concentration, and stable isotope (δ2H, δ18O, δ13C of dissolved inorganic carbon, and δ34S and δ18O of sulfate) composition. Chemical data were also investigated in terms of local meteorological data (air temperature, precipitation) to determine the sensitivity of lake parameters to changes in the surrounding environment. Groundwater represented by samples taken from Santa Susanna Spring was shown to be distinct with SO42- and Mg2+ content of 270 and 29 mg/L, respectively, and heavy sulfate isotopic composition(δ34S=15.2 ‰ and δ18O=10‰). Outflow from the Santa Susanna Spring enters Lake Ripasottile via a canal and both spring and lake water exhibits the same chemical distinctions and comparatively low seasonal variability. Major ion concentrations in Lake Lungo are similar to the Vicenna Riara Spring and are interpreted to represent the groundwater locally recharged within the plain. The δ13CDIC exhibit the same groupings as the other chemical parameters, providing supporting evidence of the source relationships. Lake Lungo exhibited exceptional ranges of δ13CDIC (±5 ‰) and δ2H, δ18O (±5 ‰ and ±7 ‰, respectively), attributed to sensitivity to seasonal changes. The hydrochemistry results, particularly major ion data, highlight how the two lakes, though geographically and morphologically similar, represent distinct hydrochemical facies. These data also show a different response in each lake to temperature and precipitation patterns in the basin that may be attributed

  8. Water-quality and lake-stage data for Wisconsin lakes, water years 2012–2013

    USGS Publications Warehouse

    Manteufel, S. Bridgett; Robertson, Dale M.

    2017-05-25

    IntroductionThe U.S. Geological Survey (USGS), in cooperation with local and other agencies, collects data at selected lakes throughout Wisconsin. These data, accumulated over many years, provide a data base for developing an improved understanding of the water quality of lakes. To make these data available to interested parties outside the USGS, the data are published annually in this report series. The locations of water-quality and lake-stage stations in Wisconsin for water year 2012 are shown in figure 1. A water year is the 12-month period from October 1 through September 30. It is designated by the calendar year in which it ends. Thus, the period October 1, 2011 through September 30, 2012, is called “water year 2012.”The purpose of this report is to provide information about the chemical and physical characteristics of Wisconsin lakes. Data that have been collected at specific lakes, and information to aid in the interpretation of those data, are included in this report. Data collected include measurements of in-lake water quality and lake stage. Time series of Secchi depths, surface total phosphorus and chlorophyll a concentrations collected during non-frozen periods are included for all lakes. Graphs of vertical profiles of temperature, dissolved oxygen, pH, and specific conductance are included for sites where these parameters were measured. Descriptive information for each lake includes: location of the lake, area of the lake’s watershed, period for which data are available, revisions to previously published records, and pertinent remarks. Additional data, such as streamflow and water quality in tributary and outlet streams of some of the lakes, are published online at http://nwis.waterdata.usgs.gov/wi/nwis.Water-resources data, including stage and discharge data at most streamflow-gaging stations, are available online. The Wisconsin Water Science Center’s home page is at https://www.usgs.gov/centers/wisconsin-water-science-center. Information on

  9. National Lakes Assessment 2012: A Collaborative Survey of Lakes in the United States

    EPA Science Inventory

    The National Lakes Assessment 2012: A Collaborative Survey of Lakes in the United States presents the results of a second evaluation of the lakes in the United States. This report is part of the National Aquatic Resource Surveys, a series of statistically based surveys designed t...

  10. Surveillance and simulation of bovine spongiform encephalopathy and scrapie in small ruminants in Switzerland

    PubMed Central

    2010-01-01

    Background After bovine spongiform encephalopathy (BSE) emerged in European cattle livestock in 1986 a fundamental question was whether the agent established also in the small ruminants' population. In Switzerland transmissible spongiform encephalopathies (TSEs) in small ruminants have been monitored since 1990. While in the most recent TSE cases a BSE infection could be excluded, for historical cases techniques to discriminate scrapie from BSE had not been available at the time of diagnosis and thus their status remained unclear. We herein applied state-of-the-art techniques to retrospectively classify these animals and to re-analyze the affected flocks for secondary cases. These results were the basis for models, simulating the course of TSEs over a period of 70 years. The aim was to come to a statistically based overall assessment of the TSE situation in the domestic small ruminant population in Switzerland. Results In sum 16 TSE cases were identified in small ruminants in Switzerland since 1981, of which eight were atypical and six were classical scrapie. In two animals retrospective analysis did not allow any further classification due to the lack of appropriate tissue samples. We found no evidence for an infection with the BSE agent in the cases under investigation. In none of the affected flocks, secondary cases were identified. A Bayesian prevalence calculation resulted in most likely estimates of one case of BSE, five cases of classical scrapie and 21 cases of atypical scrapie per 100'000 small ruminants. According to our models none of the TSEs is considered to cause a broader epidemic in Switzerland. In a closed population, they are rather expected to fade out in the next decades or, in case of a sporadic origin, may remain at a very low level. Conclusions In summary, these data indicate that despite a significant epidemic of BSE in cattle, there is no evidence that BSE established in the small ruminant population in Switzerland. Classical and atypical

  11. Lake trout (Salvelinus namaycush) suppression for bull trout (Salvelinus confluentus) recovery in Flathead Lake, Montana, North America

    USGS Publications Warehouse

    Hansen, Michael J.; Hansen, Barry S; Beauchamp, David A.

    2016-01-01

    Non-native lake trout Salvelinus namaycush displaced native bull trout Salvelinus confluentus in Flathead Lake, Montana, USA, after 1984, when Mysis diluviana became abundant following its introduction in upstream lakes in 1968–1976. We developed a simulation model to determine the fishing mortality rate on lake trout that would enable bull trout recovery. Model simulations indicated that suppression of adult lake trout by 75% from current abundance would reduce predation on bull trout by 90%. Current removals of lake trout through incentivized fishing contests has not been sufficient to suppress lake trout abundance estimated by mark-recapture or indexed by stratified-random gill netting. In contrast, size structure, body condition, mortality, and maturity are changing consistent with a density-dependent reduction in lake trout abundance. Population modeling indicated total fishing effort would need to increase 3-fold to reduce adult lake trout population density by 75%. We conclude that increased fishing effort would suppress lake trout population density and predation on juvenile bull trout, and thereby enable higher abundance of adult bull trout in Flathead Lake and its tributaries.

  12. Evidence of widespread natural reproduction by lake trout Salvelinus namaycush in the Michigan waters of Lake Huron

    USGS Publications Warehouse

    Riley, S.C.; He, J.X.; Johnson, J.E.; O'Brien, T. P.; Schaeffer, J.S.

    2007-01-01

    Localized natural reproduction of lake trout Salvelinus namaycush in Lake Huron has occurred since the 1980s near Thunder Bay, Michigan. During 2004–2006, USGS spring and fall bottom trawl surveys captured 63 wild juvenile lake trout at depths ranging from 37–73 m at four of five ports in the Michigan waters of the main basin of Lake Huron, more than five times the total number captured in the previous 30-year history of the surveys. Relatively high catches of wild juvenile lake trout in bottom trawls during 2004–2006 suggest that natural reproduction by lake trout has increased and occurred throughout the Michigan waters of the main basin. Increased catches of wild juvenile lake trout in the USGS fall bottom trawl survey were coincident with a drastic decline in alewife abundance, but data were insufficient to determine what mechanism may be responsible for increased natural reproduction by lake trout. We recommend further monitoring of juvenile lake trout abundance and research into early life history of lake trout in Lake Huron.

  13. Satellite monitoring of dramatic changes at Hawai'i's only alpine lake: Lake Waiau on Mauna Kea volcano

    USGS Publications Warehouse

    Patrick, Matthew R.; Kauahikaua, James P.

    2015-01-01

    Lake Waiau is a small, typically 100-meter-long lake, located near the summit of Mauna Kea volcano, on the Island of Hawaiʻi. It is Hawaiʻi’s only alpine lake and is considered sacred in Hawaiian cultural tradition. Over the past few years, the lake has diminished in size, and, by October 2013, surface water had almost completely disappeared from the lake. In this study, we use high-resolution satellite images and aerial photographs to document recent changes at the lake. Based on our reconstructions covering the past 200 years, the historical lake surface area has typically ranged from 5,000 to 7,000 square meters, but in 2010 a dramatic plunge in lake area ensued. The lake area rebounded significantly in early 2014, following heavy winter storms. This near disappearance of the lake, judging from analysis of visitor photographs and field reports, appears to be highly unusual, if not unprecedented, in the historical record. The unusually low water levels in the lake are consistent with a recent severe drought in Hawaiʻi.

  14. Lake Huron LAMPs

    EPA Pesticide Factsheets

    The approach in Lake Huron differs from the Lakewide Management Plans of the other Great Lakes: no formal binational designation of lakewide beneficial use impairments, nor extensive lakewide modeling of chemical loadings

  15. Great Lakes: Chemical Monitoring

    ERIC Educational Resources Information Center

    Delfino, Joseph J.

    1976-01-01

    The Tenth Great Lakes Regional Meeting of the American Chemical Society met to assess current Chemical Research activity in the Great Lakes Basin, and addressed to the various aspects of the theme, Chemistry of the Great Lakes. Research areas reviewed included watershed studies, atmospheric and aquatic studies, and sediment studies. (BT)

  16. The lakes of Titan

    USGS Publications Warehouse

    Stofan, E.R.; Elachi, C.; Lunine, J.I.; Lorenz, R.D.; Stiles, B.; Mitchell, K.L.; Ostro, S.; Soderblom, L.; Wood, C.; Zebker, H.; Wall, S.; Janssen, M.; Kirk, R.; Lopes, R.; Paganelli, F.; Radebaugh, J.; Wye, L.; Anderson, Y.; Allison, M.; Boehmer, R.; Callahan, P.; Encrenaz, P.; Flamini, E.; Francescetti, G.; Gim, Y.; Hamilton, G.; Hensley, S.; Johnson, W.T.K.; Kelleher, K.; Muhleman, D.; Paillou, P.; Picardi, G.; Posa, F.; Roth, L.; Seu, R.; Shaffer, S.; Vetrella, S.; West, R.

    2007-01-01

    The surface of Saturn's haze-shrouded moon Titan has long been proposed to have oceans or lakes, on the basis of the stability of liquid methane at the surface. Initial visible and radar imaging failed to find any evidence of an ocean, although abundant evidence was found that flowing liquids have existed on the surface. Here we provide definitive evidence for the presence of lakes on the surface of Titan, obtained during the Cassini Radar flyby of Titan on 22 July 2006 (T16). The radar imaging polewards of 70?? north shows more than 75 circular to irregular radar-dark patches, in a region where liquid methane and ethane are expected to be abundant and stable on the surface. The radar-dark patches are interpreted as lakes on the basis of their very low radar reflectivity and morphological similarities to lakes, including associated channels and location in topographic depressions. Some of the lakes do not completely fill the depressions in which they lie, and apparently dry depressions are present. We interpret this to indicate that lakes are present in a number of states, including partly dry and liquid-filled. These northern-hemisphere lakes constitute the strongest evidence yet that a condensable-liquid hydrological cycle is active in Titan's surface and atmosphere, in which the lakes are filled through rainfall and/or intersection with the subsurface 'liquid methane' table. ??2007 Nature Publishing Group.

  17. Occurrence, spatiotemporal distribution, and ecological risks of steroids in a large shallow Chinese lake, Lake Taihu.

    PubMed

    Zhou, Li-Jun; Zhang, Bei-Bei; Zhao, Yong-Gang; Wu, Qinglong L

    2016-07-01

    Steroids have been frequently detected in surface waters, and might pose adverse effects on aquatic organisms. However, little information is available regarding the occurrence and spatiotemporal distribution of steroids in lake environments. In addition to pollution sources, the occurrence and spatiotemporal distribution of steroids in lake environments might be related to lake types (shallow or deep), lake hydrodynamics, and sorption-desorption processes in the water-sediment systems. In this study, the occurrence, spatiotemporal distribution, and ecological risks of 36 steroids in a large shallow lake were evaluated by investigating surface water and sediment samples at 32 sites in Lake Taihu over two seasons. Twelve and 15 analytes were detected in aqueous and sedimentary phases, respectively, with total concentrations ranging from 0.86 to 116ng/L (water) and from 0.82 to 16.2ng/g (sediment, dry weight). Temporal variations of steroid concentrations in the water and sediments were statistically significant, with higher concentrations in winter. High concentrations of steroids were found in the seriously polluted bays rather than in the pelagic zone of the lake. Strong lake currents might mix pelagic waters, resulting in similar concentrations of steroids in the pelagic zone. Mass balance analysis showed that sediments in shallow lakes are in general an important sink for steroids. Steroids in the surface water and sediments of Lake Taihu might pose potential risks to aquatic organisms. Overall, our study indicated that the concentrations and spatiotemporal distribution of steroids in the large shallow lake are influenced simultaneously by pollution sources and lake hydrodynamics. Steroids in the large shallow Lake Taihu showed clear temporal and spatial variations and lake sediments may be a potential sink of steroids. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Diet of lake trout and burbot in northern Lake Michigan during spring: Evidence of ecological interaction

    USGS Publications Warehouse

    Jacobs, Gregory R.; Madenjian, Charles P.; Bunnell, David B.; Holuszko, Jeffrey D.

    2010-01-01

    We used analyses of burbot (Lota lota) and lake trout (Salvelinus namaycush) diets taken during spring gill-net surveys in northern Lake Michigan in 2006-2008 to investigate the potential for competition and predator-prey interactions between these two species. We also compared our results to historical data from 1932. During 2006-2008, lake trout diet consisted mainly of alewives (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax), whereas burbot utilized a much wider prey base including round goby (Neogobius melanostomus), rainbow smelt, alewives, and sculpins. Using the Schoener's diet overlap index, we found a higher potential for interspecific competition in 1932 than in 2006-2008, though diet overlap was not significant in either time period. No evidence of cannibalism by lake trout or lake trout predation on burbot was found in either time period. In 2006-2008, however, lake trout composed 5.4% (by weight) of burbot diet. To determine whether this predation could be having an impact on lake trout rehabilitation efforts in northern Lake Michigan, we developed a bioenergetic-based consumption estimate for burbot on Boulder Reef (a representative reef within the Northern Refuge) and found that burbot alone can consume a considerable proportion of the yearling lake trout stocked annually, depending on burbot density. Overall, we conclude that predation, rather than competition, is the more important ecological interaction between burbot and lake trout, and burbot predation may be contributing to the failed lake trout rehabilitation efforts in Lake Michigan.

  19. 33 CFR 162.220 - Hoover Dam, Lake Mead, and Lake Mohave (Colorado River), Ariz.-Nev.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Mohave (Colorado River), Ariz.-Nev. 162.220 Section 162.220 Navigation and Navigable Waters COAST GUARD... REGULATIONS § 162.220 Hoover Dam, Lake Mead, and Lake Mohave (Colorado River), Ariz.-Nev. (a) Lake Mead and... the axis of Hoover Dam and that portion of Lake Mohave (Colorado River) extending 4,500 feet...

  20. Revascularization Treatment of Emergency Patients with Acute ST-Segment Elevation Myocardial Infarction in Switzerland: Results from a Nationwide, Cross-Sectional Study in Switzerland for 2010-2011.

    PubMed

    Berlin, Claudia; Jüni, Peter; Endrich, Olga; Zwahlen, Marcel

    2016-01-01

    Cardiovascular diseases are the leading cause of death worldwide and in Switzerland. When applied, treatment guidelines for patients with acute ST-segment elevation myocardial infarction (STEMI) improve the clinical outcome and should eliminate treatment differences by sex and age for patients whose clinical situations are identical. In Switzerland, the rate at which STEMI patients receive revascularization may vary by patient and hospital characteristics. To examine all hospitalizations in Switzerland from 2010-2011 to determine if patient or hospital characteristics affected the rate of revascularization (receiving either a percutaneous coronary intervention or a coronary artery bypass grafting) in acute STEMI patients. We used national data sets on hospital stays, and on hospital infrastructure and operating characteristics, for the years 2010 and 2011, to identify all emergency patients admitted with the main diagnosis of acute STEMI. We then calculated the proportion of patients who were treated with revascularization. We used multivariable multilevel Poisson regression to determine if receipt of revascularization varied by patient and hospital characteristics. Of the 9,696 cases we identified, 71.6% received revascularization. Patients were less likely to receive revascularization if they were female, and 80 years or older. In the multivariable multilevel Poisson regression analysis, there was a trend for small-volume hospitals performing fewer revascularizations but this was not statistically significant while being female (Relative Proportion = 0.91, 95% CI: 0.86 to 0.97) and being older than 80 years was still associated with less frequent revascularization. Female and older patients were less likely to receive revascularization. Further research needs to clarify whether this reflects differential application of treatment guidelines or limitations in this kind of routine data.

  1. Great Minds? Great Lakes!

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Chicago, IL. Great Lakes National Program Office.

    This book contains lesson plans that provide an integrated approach to incorporating Great Lakes environmental issues into elementary subjects. The book is divided into three subject areas: (1) History, which includes the origins of the Great Lakes, Great Lakes people, and shipwrecks; (2) Social Studies, which covers government, acid rain as a…

  2. Great Salt Lake Microbial Communities: The Foundation of a Terminal Lake Ecosystem

    NASA Astrophysics Data System (ADS)

    Baxter, B. K.; Acord, M.; Riddle, M. R.; Avery, B.

    2006-12-01

    Great Salt Lake (GSL) is a natural hypersaline ecosystem and a terminal lake of substantial size. The dramatic fluctuation in water levels and salinity creates an ecological backdrop selective for organisms with a high degree of adaptability. At the macro level, the biodiversity of the GSL ecosystem is simple, due to the limitations of an extreme saline environment: Birds eat the two invertebrates of the lake, and the invertebrates eat phytoplankton. However, analysis of the microbial level reveals an enormous diversity of species interacting with one another and the ecosystem as a whole. Our cultivation, biochemical tests, microscopy and DNA sequencing yielded data on dozens of isolates. These data demonstrate novel species, and possibly genera, living in the lake. In addition, we have discovered viruses (bacteriophage) that prey on the microorganisms. Preliminary data on bacteria dwelling in the gut of the brine shrimp, Artemia franciscana, link these prokaryotic organisms to the food chain for the first time. All of these results taken together open the door for the discussion of the significance of the microbial level of terminal lake ecosystem, particularly in light of lake water contamination and bioremediation possibilities.

  3. Development of Clinical Pharmacy in Switzerland: Involvement of Community Pharmacists in Care for Older Patients.

    PubMed

    Hersberger, Kurt E; Messerli, Markus

    2016-03-01

    The role of the community pharmacist in primary care has been undergoing change in Switzerland in parallel to international developments: it has become more clinically and patient oriented. Special services of community pharmacists to older patients taking long-term or multiple medications, discharged from hospitals or experiencing cognitive impairment or disability have been developed. These services require more clinical knowledge and skills from community pharmacists and are based on, for example, 'simple or intermediate medication reviews' focused primarily to improve medication adherence and rational drug use by a patient. Reflecting the new role of community pharmacies, this article describes the current services provided by community pharmacies in Switzerland, e.g., 'polymedication check', 'weekly pill organizer', and 'services for chronic patients', as well as new Swiss educational and reimbursement systems supporting development of these services. In the international context, involvement of community pharmacists in patient-oriented care is growing. This review summarizes positive and negative experiences from implementation of community pharmacy services in Switzerland and provides examples for the development of such services in other countries.

  4. [Growing-up of children from HIV-positive mothers in Switzerland. Pediatric AIDS-Group Switzerland].

    PubMed

    Künzel, M; Kind, C

    1992-04-04

    The social situation (placements, material conditions, needs) of children of HIV-infected mothers living in Switzerland was studied and their future needs were estimated. Data were gathered by anonymous questionnaires mailed to the primary care physicians of the children of HIV-infected mothers registered in the Swiss Neonatal HIV Study. The physicians handed a copy to the parents or guardians. The social situation could be adequately evaluated for 84 children. With respect to the proportion of mothers with a history of intravenous drug use (75%) or of foreign origin (19%), the children did not differ significantly from the whole population represented in the Swiss Neonatal HIV Study. Of a total of 3154 months, the children spent 75% with their natural mother, 14% with other family members, 6% in a foster family, 3% in a foster home and 2% with adoptive parents. At the time of the study 32 children (38%) could not be cared for by their own mother. The cumulative probability (by the Kaplan-Meier method) of continuing care by the mother was estimated at 78%, 70%, 60% and 50% for an age of 12, 24, 36 and 48 months respectively. Maternal reasons for placement in foster care were: enrollment in an institutional drug withdrawal program (11), neglect (8), death (8) or illness (5). The following ways of improving social conditions were identified: social acceptance without discrimination, early planning of the future care of children in anticipation of the imminent disruption of the family, financial support, assistance in baby sitting and support groups for parents and guardians. A minimum annual requirement of 25 new foster care places for children of HIV-infected mothers can be estimated--assuming a stable annual incidence of some 50 deliveries of seropositive women in Switzerland. For primary care physicians it is a major challenge to stay sufficiently informed about the ever changing social situation in order to identify the often wide variety of assistance needed by

  5. Palaeolimnological evidence of vulnerability of Lake Neusiedl (Austria) toward climate related changes since the last "vanished-lake" stage.

    NASA Astrophysics Data System (ADS)

    Tolotti, Monica; Milan, Manuela; Boscaini, Adriano; Soja, Gerhard; Herzig, Alois

    2013-04-01

    The palaeolimnological reconstruction of secular evolution of Euroepan Lakes with key socio-economical relevance respect to large (climate change) and local scale (land use, tourism) environmental changes, represents one of the objectives of the project EuLakes (European Lakes Under Environmental Stressors, Supporting lake governance to mitigate the impact of climate change, Reg. N. 2CE243P3), launched in 2010 within the Central European Inititiative. The project consortium comprises lakes of different morphology and prevalent human uses, including the meso-eutrophic Lake Neusiedl, the largest Austrian lake (total area 315 km2), and the westernmost shallow (mean depth 1.2 m) steppe lake of the Euro-Asiatic continent. The volume of Lake Neusiedl can potentially change over the years, in relation with changing balance between atmospheric precipitation and lake water evapotranspiration. Changing water budget, together with high lake salinity and turbidity, have important implications over the lake ecosystem. This contribution illustrates results of the multi-proxi palaeolimnological reconstruction of ecologial changes occurred in Lake Neusiedl during the last ca. 140 years, i.e. since the end of the last "vanished-lake" stage (1865-1871). Geochemical and biological proxies anticipate the increase in lake productivity of ca. 10 years (1950s) respect to what reported in the literature. Diatom species composition indicate a biological lake recovery in the late 1980s, and suggest a second increment in lake productivity since the late 1990s, possibly in relation with the progressive increase in the nitrogen input from agriculture. Abundance of diatoms typical of brackish waters indicated no significant long-term change in lake salinity, while variations in species toleranting dessiccation confirm the vulnerability of Lake Neusiedl toward climate-driven changes in the lake water balance. This fragility is aggravated by the the semi-arid climate conditions of the catchemnt

  6. Geography of Alaska Lake Districts: Identification, Description, and Analysis of Lake-Rich Regions of a Diverse and Dynamic State

    USGS Publications Warehouse

    Arp, Christopher D.; Jones, Benjamin M.

    2009-01-01

    Lakes are abundant landforms and important ecosystems in Alaska, but are unevenly distributed on the landscape with expansive lake-poor regions and several lake-rich regions. Such lake-rich areas are termed lake districts and have landscape characteristics that can be considered distinctive in similar respects to mountain ranges. In this report, we explore the nature of lake-rich areas by quantitatively identifying Alaska's lake districts, describing and comparing their physical characteristics, and analyzing how Alaska lake districts are naturally organized and correspond to climatic and geophysical characteristics, as well as studied and managed by people. We use a digital dataset (National Hydrography Dataset) of lakes greater than 1 hectare, which includes 409,040 individual lakes and represents 3.3 percent of the land-surface area of Alaska. The selection criteria we used to identify lake districts were (1) a lake area (termed limnetic ratio, in percent) greater than the mean for the State, and (2) a lake density (number of lakes per unit area) greater than the mean for the State using a pixel size scaled to the area of interest and number of lakes in the census. Pixels meeting these criteria were grouped and delineated and all groups greater than 1,000 square kilometers were identified as Alaska's lake districts. These lake districts were described according to lake size-frequency metrics, elevation distributions, geology, climate, and ecoregions to better understand their similarities and differences. We also looked at where lake research and relevant ecological monitoring has occurred in Alaska relative to lake districts and how lake district lands and waters are currently managed. We identified and delineated 20 lake districts in Alaska representing 16 percent of the State, but including 65 percent of lakes and 75 percent of lake area. The largest lake districts identified are the Yukon-Kuskokwim Delta, Arctic Coastal Plain, and Iliamna lake districts with

  7. Private Funding and Its Dangers to Academia: An Experience in Switzerland

    ERIC Educational Resources Information Center

    Hugentobler, Manuela; Müller, Markus; Morrissey, Franz Andres

    2017-01-01

    Academic freedom, a deep-rooted right in the Swiss Constitution, is endangered. Private sponsorship agreements, secretly negotiated between university leaders and big companies, become increasingly vital for universities in Switzerland. Swiss authorities are pushing this development: not only are they taking austerity measures, but also rewarding…

  8. ARE LAKES GETTING WARMER? REMOTE SENSING OF LARGE LAKE TEMPERATURES

    EPA Science Inventory

    Recent studies (Levitus et al., 2000) suggest a warning of the world ocean over the past 50 years. Freshwater lakes could also be getting warmer but thermal measurements to determine this are lacking. Large lake temperatures are vertically and horizontally heterogeneous and vary ...

  9. L-Lake macroinvertebrate community

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Specht, W.L.

    1996-06-01

    To characterize the present benthic macroinvertebrate community of L-Lake, Regions 5 and 7 of the reservoir were sampled in September 1995 at the same locations sampled in 1988 and 1989 during the L-Lake monitoring program. The macroinvertebrate community of 1995 is compared to that of 1988 and 1989. The species composition of L-Lake`s macroinvertebrate community has changed considerably since 1988-1989, due primarily to maturation of the reservoir ecosystem. L-Lake contains a reasonably diverse macroinvertebrate community that is capable of supporting higher trophic levels, including a diverse assemblage of fish species. The L-Lake macroinvertebrate community is similar to those of manymore » other southeastern reservoirs, and there is no indication that the macroinvertebrate community is perturbed by chemical or physical stressors.« less

  10. Water-quality and lake-stage data for Wisconsin lakes, water years 2008−2011

    USGS Publications Warehouse

    Manteufel, S. Bridgett; Olson, Daniel L.; Robertson, Dale M.; Goddard, Gerald L.

    2016-09-30

    The U.S. Geological Survey (USGS), in cooperation with local and other agencies, collects data at selected lakes throughout Wisconsin. These data, accumulated over many years, provide a data base for developing an improved understanding of the water quality of lakes. To make these data available to interested parties outside the USGS, the data are published annually in this report series.The purpose of this report is to provide information about the chemical and physical characteristics of Wisconsin lakes during water years 2008–2011. A water year is the 12-month period from October 1 through September 30. It is designated by the calendar year in which it ends. Thus, the period October 1, 2007 through September 30, 2008 is called "water year 2008." Data that have been collected at specific lakes, and information to aid in the interpretation of those data, are presented in this report for water years from 2008–2011. Data collected include measurements of in-lake water quality and lake stage. Time series of Secchi depths, surface total phosphorus and chlorophyll a concentrations collected during non-frozen periods are included for all lakes. Graphs of vertical profiles of temperature, dissolved oxygen, pH, and specific conductance are included for sites where these parameters were measured. Descriptive information for each lake includes: location of the lake, area of the lake’s watershed, period for which data are available, revisions to previously published records, and pertinent remarks. Additional data, such as streamflow and water quality in tributary and outlet streams of some of the lakes, are available via the "USGS Annual Water Data Report" Web site: http://wdr.water.usgs.gov/.

  11. Hydrological and solute budgets of Lake Qinghai, the largest lake on the Tibetan Plateau

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jin, Zhangdong; You, Chen-Feng; Wang, Yi

    2009-12-04

    Water level and chemistry of Lake Qinghai are sensitive to climate changes and are important for paleoclimatic implications. An accurate understanding of hydrological and chemical budgets is crucial for quantifying geochemical proxies and carbon cycle. Published results of water budget are firstly reviewed in this paper. Chemical budget and residence time of major dissolved constituents in the lake are estimated using reliable water budget and newly obtained data for seasonal water chemistry. The results indicate that carbonate weathering is the most important riverine process, resulting in dominance of Ca 2+ and DIC for river waters and groundwater. Groundwater contribution tomore » major dissolved constituents is relatively small (4.2 ± 0.5%). Wet atmospheric deposition contributes annually 7.4–44.0% soluble flux to the lake, resulting from eolian dust throughout the seasons. Estimates of chemical budget further suggest that (1) the Buha-type water dominates the chemical components of the lake water, (2) Na +, Cl -, Mg 2+ , and K + in lake water are enriched owing to their conservative behaviors, and (3) precipitation of authigenic carbonates (low-Mg calcite, aragonite, and dolomite) transits quickly dissolved Ca 2+ into the bottom sediments of the lake, resulting in very low Ca 2+ in the lake water. Therefore, authigenic carbonates in the sediments hold potential information on the relative contribution of different solute inputs to the lake and the lake chemistry in the past.« less

  12. An evaluation of lake trout reproductive habitat on Clay Banks Reef, northwestern Lake Michigan

    USGS Publications Warehouse

    Edsall, Thomas A.; Holey, Mark E.; Manny, Bruce A.; Kennedy, Gregory W.

    1995-01-01

    The extinction of the native populations of lake trout (Salvelinus namaycush) in Lake Michigan in about 1956 has been followed by a decades-long attempt to reestablish self-sustaining populations of this valuable species in habitats it formerly occupied throughout the lake. One of the most recent management strategies designed to facilitate recovery was to make a primary management objective the establishment of sanctuaries where stocked lake trout could be protected and self-sustaining populations reestablished. In the present study we employed habitat survey and mapping techniques, field and laboratory bioassays, egg traps, sediment traps, and gill nets to examine the potential for successful natural reproduction by stocked lake trout on Clay Banks Reef in the Door-Kewaunee sanctuary in Wisconsin waters of Lake Michigan. Our study revealed (1) there was suitable habitat on the reef to support the production of viable fry, (2) spawner abundance on the reef was the highest recorded in the great lakes, and (3) eggs taken from spawners on the reef and held on the reef in plexiglas incubators hatched and produced fry that survived through swim-up. We conclude that Clay Banks Reef has the potential to support successful natural reproduction by stocked lake trout.

  13. Ecology of playa lakes

    USGS Publications Warehouse

    Haukos, David A.; Smith, Loren M.

    1992-01-01

    Between 25,000 and 30,000 playa lakes are in the playa lakes region of the southern high plains (Fig. 1). Most playas are in west Texas (about 20,000), and fewer, in New Mexico, Oklahoma, Kansas, and Colorado. The playa lakes region is one of the most intensively cultivated areas of North America. Dominant crops range from cotton in southern areas to cereal grains in the north. Therefore, most of the native short-grass prairie is gone, replaced by crops and, recently, grasses of the Conservation Reserve Program. Playas are the predominant wetlands and major wildlife habitat of the region.More than 115 bird species, including 20 species of waterfowl, and 10 mammal species have been documented in playas. Waterfowl nest in the area, producing up to 250,000 ducklings in wetter years. Dominant breeding and nesting species are mallards and blue-winged teals. During the very protracted breeding season, birds hatch from April through August. Several million shorebirds and waterfowl migrate through the area each spring and fall. More than 400,000 sandhill cranes migrate through and winter in the region, concentrating primarily on the larger saline lakes in the southern portion of the playa lakes region.The primary importance of the playa lakes region to waterfowl is as a wintering area. Wintering waterfowl populations in the playa lakes region range from 1 to 3 million birds, depending on fall precipitation patterns that determine the number of flooded playas. The most common wintering ducks are mallards, northern pintails, green-winged teals, and American wigeons. About 500,000 Canada geese and 100,000 lesser snow geese winter in the playa lakes region, and numbers of geese have increased annually since the early 1980’s. This chapter describes the physiography and ecology of playa lakes and their attributes that benefit waterfowl.

  14. Ethical research on the implementation of DRGs in Switzerland--a challenging project.

    PubMed

    Wild, Verina; Pfister, Eliane; Biller-Andorno, Nikola

    2012-08-09

    Diagnosis Related Groups (DRGs) are currently being introduced on a national scale as a prospective reimbursement scheme in Swiss in-patient hospital care, replacing any remaining retrospective day-rate arrangements. DRGs are expected to promote transparency and efficiency while helping to contain health care costs. The governmental decision to introduce DRGs has caused considerable controversy among different stakeholders, due to diverging appraisals of what will happen when DRGs are introduced as an economic management tool in Switzerland. The controversial discourse on DRGs is particularly interesting from an ethical point of view, since all arguments inevitably contain ethical considerations. In this paper we summarise the results of our exploratory ethical studies that have led to a larger research project funded by the Swiss National Science Foundation: "Impact of Diagnosis-Related Groups (DRGs) on patient care and professional practice" (IDoC). In section 1: 'Developing an understanding of the ethical issues at stake' we briefly explain how DRGs work, what the intended effects are, what the public is concerned about and what the scientific research tells us so far. In section 2: 'Developing an ethical framework for research on DRGs in Switzerland' we summarise the ethical issues and explain the ethical framework we will use in order to perform research on the complex issue of DRGs in Switzerland. Only once a profound understanding of the challenges exists can research on the ethical implications of DRGs be successful.

  15. Examining indirect effects of lake trout recovery

    EPA Science Inventory

    With the recovery of lake trout populations in Lake Superior, there are indications of decreased forage fish abundance and density-dependence in lake trout. In Lake Superior, lean lake trout historically occupied depths < 60 m, and siscowet lake trout occupied depths > 60 m...

  16. Hatchery Contributions to Emerging Naturally Produced Lake Huron Lake Trout.

    PubMed

    Scribner, Kim; Tsehaye, Iyob; Brenden, Travis; Stott, Wendylee; Kanefsky, Jeannette; Bence, James

    2018-06-19

    Recent assessments indicate the emergence of naturally produced lake trout (Salvelinus namaycush) recruitment throughout Lake Huron in the North American Laurentian Great Lakes (>50% of fish <7 yrs). Because naturally produced fish derived from different stocked hatchery strains are unmarked, managers cannot distinguish strains contributing to natural recruitment. We used 15 microsatellite loci to identify strains of naturally produced lake trout (N=1567) collected in assessment fisheries during early (2002-2004) and late (2009-2012) sampling periods. Individuals from 13 American and Canadian hatchery strains (N=1143) were genotyped to develop standardized baseline information. Strain contributions were estimated using a Bayesian inferential approach. Deviance information criteria was used to compare models evaluating strain contributions at different spatial and temporal scales. The best performing models were the most complex models, suggesting that hatchery strain contributions to naturally produced lake trout varied spatially among management districts and temporally between time periods. Contributions of Seneca strain lake trout were consistently high across most management districts, with contributions increasing from early to late time periods (estimates ranged from 52-94% for the late period across eight of nine districts). Strain contributions deviated from expectations based on historical stocking levels, indicating strains differed with respect to survival, reproductive success, and/or dispersal. Knowledge of recruitment levels of strains stocked in different management districts, and how strain-specific recruitment varies temporally, spatially, and as a function of local or regional stocking is important to prioritize strains for future stocking and management of the transition process from primarily hatchery to naturally produced stocks.

  17. Introduction to the Proceedings of the 1994 International Conference on Restoration of Lake Trout in the Laurentian Great Lakes

    USGS Publications Warehouse

    Selgeby, James H.

    1995-01-01

    Lake trout (Salvelinus namaycush) restoration in the Great Lakes began in the 1950s when stocking of artificially propagated lake trout was coupled with the first attempts at sea lamprey (Petromyzon marinus) control. A major milestone in the restoration process was recorded when a selective sea lamprey larvicide was identified in 1958 (Applegate et al. 1958) and then applied broad scale in Lake Superior in 1958-60 (Applegate et al. 1961). Other milestones include the expansion of the sea lamprey control programs into Lakes Michigan and Huron in 1960 (sustained usage in Lake Huron began in 1966, Smith and Tibbles 1980), Lake Ontario in 1971-72 (Elrod et al. 1995), and Lake Erie in 1986 (Cornelius et al. 1995). Following the collapse of lake trout in the Great Lakes and the implementation of massive stocking of hatchery-reared fish and effective sea lamprey control, the first documented evidence of nearshore natural reproduction of lake trout was in Lake Superior in 1965 (Dryer and King 1968), in Lake Michigan in 1980 (Jude et al. 1981), in Lake Huron in 1981-82 (Nester and Poe 1984), and in Lake Ontario in 1986 (Marsden et al. 1988).

  18. Influence of geomorphic setting on sedimentation of two adjacent alpine lakes, Triglav Lakes Valley (Julian Alps, NW Slovenia)

    NASA Astrophysics Data System (ADS)

    Smuc, Andrej; Skabene, Dragomir; Muri, Gregor; Vreča, Polona; Jaćimović, Radojko; Čermelj, Branko; Turšič, Janja

    2013-04-01

    The Triglav Lakes Valley is elongated, 7km long depression, located high (at places over 2000 m.a.s.l.) in the central part of the Julian Alps (NW Slovenia). It hosts 6 small isolated lakes that formed due to the combination of Neogene tectonic and Pleistocene glaciation. The study is focused on the 5th and 6th Triglav Valley Lakes that characterize lower part of the valley. The lakes are located so close to each other that they are even connected in times of high water. Thus, they share the same bedrock geology, are subjected to the same climatic forcing and share similar vegetation communities. Despite their proximity, the lakes differ in their hydrologic and geomorphic setting. The lakes have no permanent surface tributaries; however 5th is fed periodically, at times of high water level, by the Močivec spring, while additional water flows from the swamp area near its northern shore. An underground spring on the eastern side of 5th represents the lake's only permanent freshwater inflow, while drainage takes place to the west via a small ponor. 6th has only one weak underground spring on the eastern side of the lake. Water levels may fluctuate between 2 and 3 m. Additionally, the lakes have different configuration of lakes shores; the northern shores of the 5th lake are low-angle soil and debris covered plateau, while southern shores of the 5th lake and shores of the 6th lake are represented by heavily karstified carbonate base rock and covered partly by trees. The detailed sedimentary analysis of the lakes record showed some similarities, but also some significant differences. Sediments of both lakes are represented by fine-grained turbidity current deposits that are transported from lake shores during snow melt or storms. The grain-size and sedimentary rates of the lakes are however markedly different. The 5th lake has coarser grained sediments, with mean ranging from 46 to 60 µm and records higher sedimentation rates of ~0,57 cm/year, compared to the 6th lake

  19. Early observations on an emerging Great Lakes invader Hemimysis anomala in Lake Ontario

    USGS Publications Warehouse

    Walsh, Maureen G.; Lantry, Brian F.; Boscarino, Brent; Bowen, Kelly; Gerlofsma, Jocelyn; Schaner, Ted; Back, Richard; Questel, Jennifer; Smythe, A. Garry; Cap, Roberta; Goehle, Michael; Young, Bryan; Chalupnicki, Marc A.; Johnson, James H.; McKenna, James E.

    2010-01-01

    Hemimysis anomala, a Ponto-Caspian littoral mysid, is an emerging Great Lakes invader that was discovered in Lakes Michigan and Ontario in 2006. Similar to the native mysid Mysis diluviana, Hemimysis exhibits a diel vertical migration pattern but generally inhabits shallower and warmer waters than M. diluviana. Because basic information on the distribution, habitat use, and biology of Hemimysis in the Great Lakes is scarce, the potential for food web disruption by Hemimysis cannot easily be predicted. Preliminary observations indicate widespread invasion of Hemimysis in Lake Ontario. In this study, we confirm the presence of Hemimysis at sites spanning the northern and southern shores of Lake Ontario and the presence of the individuals during winter months. In one horizontal tow in November 2007, over 26,000 individuals were collected with a length range of 4.4 to 9.0. mm and an average caloric density of 611. cal/g wet weight. The most effective methods for sampling Hemimysis were horizontal tows with either a zooplankton net in the water column or a benthic sled near the lake bottom. Although more quantitative data on the life history and distribution of this species is necessary, our preliminary observations support the prediction that the potential for Hemimysis to impact the nearshore food web in Lake Ontario appears high.

  20. Lakes on Titan

    NASA Image and Video Library

    2006-07-24

    The Cassini spacecraft, using its radar system, has discovered very strong evidence for hydrocarbon lakes on Titan. Dark patches, which resemble terrestrial lakes, seem to be sprinkled all over the high latitudes surrounding Titan north pole

  1. Temperature Trends in Montane Lakes

    NASA Astrophysics Data System (ADS)

    Melack, J. M.; Sadro, S.; Jellison, R.

    2014-12-01

    Long-term temperature trends in lakes integrate hydrological and meteorological factors. We examine temperature trends in a small montane lake with prolonged ice-cover and large seasonal snowfall and in a large saline lake. Emerald Lake, located in the Sierra Nevada (California), is representative of high-elevation lakes throughout the region. No significant trend in outflow temperature was apparent from 1991to 2012. Snowfall in the watershed accounted for 93% of the variability in average summer lake temperatures. Mono Lake (California) lies in a closed, montane basin and is hypersaline and monomictic or meromictic. Temperature profiles have been collected from 1982 to 2010. In the upper water column, the July-August-September water temperatures increased 0.8-1.0°C over the 29 years. This rate of warming is less than published estimates based on satellite-derived skin temperatures and will discussed in the context of general limnological interpretation of temperature trends.

  2. Habitat Suitability Index Models: Lake trout (exclusive of the Great Lakes)

    USGS Publications Warehouse

    Marcus, Michael D.; Hubert, Wayne A.; Anderson, Stanley H.

    1984-01-01

    The lake trout is an important commercial and sport fish in North America. In the Central Rocky Mountain regi on, 1ake trout are common ly referred to as "mackinaw". There is good evidence that lake trout should be called "1 ake charr" (Morton 1980). No subspecies of lake trout is presently recognized (Robins et al. 1980). The species, however, has extreme variability throughout its range, making it difficult to draw general conclusions about its biology (Martin and Olver 1980).

  3. The economic burden of depression in Switzerland.

    PubMed

    Tomonaga, Yuki; Haettenschwiler, Josef; Hatzinger, Martin; Holsboer-Trachsler, Edith; Rufer, Michael; Hepp, Urs; Szucs, Thomas D

    2013-03-01

    Despite the high prevalence of depression, information about the burden of this disease in Switzerland is scarce. A better knowledge of the costs of depression may provide important information for future national preventive programmes, optimizing cost-effective budgeting. The estimates of national costs may improve the public's awareness of depression and depression-related costs, breaking down the taboo of depression as an illness. The aims of this study were to analyse the annual cost for different levels of depression and to investigate the annual economic burden of depression in Switzerland. A retrospective, multicentre, non-interventional study in psychiatrist practices was carried out. Outpatients who had been diagnosed with depression in the last 3 years were included. Patient demographics and information on clinical characteristics and resource utilization in the first 12 months after diagnosis were collected. Costs analysis, subdivided into direct and indirect costs, was performed for three depression severity classes (mild, moderate and severe), according to the 17-item Hamilton Depression Rating Scale (HDRS-17). Costs were also extrapolated to a national level. Regression analysis was performed to control for factors that may have an impact on the cost of depression. A total of 556 patients were included. Hospitalization and hospitalization days were directly correlated with disease severity (p < 0.001). Medical resource utilization linked to depression and antidepressant treatments was also correlated to the disease status. Severely depressed patients reported a significantly higher number of workdays lost and were significantly more often on disability insurance. The mean total direct costs per person per year, mainly due to hospitalization costs, were 3,561 for mild, 9,744 for moderate and 16,240 for severe depression. The mean indirect costs per person per year, mainly due to workdays lost, were 8,730 for mild, 12

  4. Great Lakes in January

    NASA Image and Video Library

    2017-12-08

    This image taken on January 13, 2015 from the Suomi NPP satellite's VIIRS instrument shows the Great Lakes and surrounding areas. The latest Great Lakes Surface Environmental Analysis (GLSEA) from the NOAA Great Lakes Environmental Research Laboratory shows total ice cover of 29.3% as of January 13th. Credit: NOAA/NASA/NPP Via NOAA Environmental Visualization Laboratory

  5. Limnological and water-quality data from Wonder Lake, Chilchukabena Lake, and Lake Minchumina, Denali National Park and Preserve and surrounding area, Alaska, June 2006-August 2008

    USGS Publications Warehouse

    Long, D.A.; Arp, C.D.

    2011-01-01

    Growing visitor traffic and resource use, as well as natural and anthropogenic land and climatic changes, can place increasing stress on lake ecosystems in Denali National Park and Preserve. Baseline data required to substantiate impact assessment in this sub-arctic region is sparse to non-existent. The U.S. Geological Survey, in cooperation with the National Park Service, conducted a water-quality assessment of several large lakes in and around the Park from June 2006 to August 2008. Discrete water-quality samples, lake profiles of pH, specific conductivity, dissolved-oxygen concentration, water temperature, turbidity, and continuous-record temperature profile data were collected from Wonder Lake, Chilchukabena Lake, and Lake Minchumina. In addition, zooplankton, snow chemistry data, fecal coliform, and inflow/outflow water-quality samples also were collected from Wonder Lake.

  6. Wet trend continues for lakes

    NASA Astrophysics Data System (ADS)

    Katzoff, Judith A.

    About 20% of the United States, including the regions of the Great Lakes and the Great Salt Lake, has entered a fourth year of record and near-record streamflow and lake levels, according to the U.S. Geological Survey (USGS). From June 3 until June 8, 1986, the Great Salt Lake stood at 1283.77 m above sea level, 0.076 m above the previous record, which was set in 1873. (Records have been kept for the lake since 1847.) On June 8, a dike south of the lake gave way during a windstorm, causing flooding of evaporation ponds used for mineral recovery.As a result of the breach, the lake's level dropped to 1283.65 m above sea level by June 10 but rose to 1283.68 m by June 20. The latest official reading, made on June 30, showed that the lake's level had dropped to 1283.63 m above sea level. According to Tom Ross, chief of the Current Water Conditions Group at the USGS National Center in Reston, Va., this drop represents “a normal seasonal decline brought on by evaporation.”

  7. Three-Dimensional Simulation of Avalanche-Generated Impulse Waves and Evaluation of Lake-Lowering Scenarios at Lake Palcacocha, Peru

    NASA Astrophysics Data System (ADS)

    Chisolm, R. E.; McKinney, D. C.

    2014-12-01

    Accelerated retreat of Andean glaciers in recent decades due to a warming climate has caused the emergence and growth of glacial lakes. As these lakes continue to grow, they pose an increasing risk of glacial lake outburst floods (GLOFs). GLOFs can be triggered by moraine failures or by avalanches, rockslides, or ice calving into glacial lakes. For many decades Lake Palcacocha in the Cordillera Blanca, Peru has threatened citizens living in the city of Huaraz which was devastated by a GLOF in 1941. A safety system for Lake Palcacocha was put in place in the 1970's to control the lake level, but the lake has since grown to the point where it is once again dangerous. Overhanging ice from the glaciers above and a relatively low freeboard make the lake vulnerable to avalanches and landslides. Lake Palcacocha is used as a case study to investigate the impact of an avalanche event on the lake dynamics. Three-dimensional lake modeling in the context of glacial hazards is not common, but 3D simulations can enhance our understanding of avalanche-generated impulse waves and their downstream impacts. In this work, a 3D hydrodynamic model is used to simulate the generation of an impulse wave from an avalanche falling into the lake, wave propagation, and overtopping of the terminal moraine. These results are used as inputs to a downstream model to predict the impact from a GLOF. As lowering the level of the lake is the most likely mitigation alternative, several scenarios are considered to evaluate the impact from avalanche events with a reduction in the lake level. The results of this work can be used to evaluate the effectiveness of the current lake management system and potential lake-lowering alternatives. Use of a robust 3D lake model enables more accurate predictions of peak flows during GLOF events and the time scales of these events so that mitigation strategies can be developed that reduce the risk to communities living downstream of hazardous lakes.

  8. The Lake-Catchment (LakeCat) Dataset for characterizing hydrologically-relevant landscape features for lakes across the conterminous US

    EPA Science Inventory

    Lake conditions, including their biota, respond to both natural and human-related landscape features. Characterizing these features within the contributing areas (i.e., delineated watersheds) of lakes could improve the analysis and the sustainable use and management of these impo...

  9. The near extinction of lake trout in Lake Michigan

    USGS Publications Warehouse

    Eschmeyer, Paul H.

    1957-01-01

    Comparisons in 1949 and 1950 of numbers of legal-sized lake trout caught in large-mesh nets with numbers of small fish taken in chub nets showed that both large and small lake trout declined over the same period, and that by these years the decline may have been greater among small than among legal-sized fish.

  10. Decline of the world's saline lakes

    NASA Astrophysics Data System (ADS)

    Wurtsbaugh, Wayne A.; Miller, Craig; Null, Sarah E.; Derose, R. Justin; Wilcock, Peter; Hahnenberger, Maura; Howe, Frank; Moore, Johnnie

    2017-11-01

    Many of the world's saline lakes are shrinking at alarming rates, reducing waterbird habitat and economic benefits while threatening human health. Saline lakes are long-term basin-wide integrators of climatic conditions that shrink and grow with natural climatic variation. In contrast, water withdrawals for human use exert a sustained reduction in lake inflows and levels. Quantifying the relative contributions of natural variability and human impacts to lake inflows is needed to preserve these lakes. With a credible water balance, causes of lake decline from water diversions or climate variability can be identified and the inflow needed to maintain lake health can be defined. Without a water balance, natural variability can be an excuse for inaction. Here we describe the decline of several of the world's large saline lakes and use a water balance for Great Salt Lake (USA) to demonstrate that consumptive water use rather than long-term climate change has greatly reduced its size. The inflow needed to maintain bird habitat, support lake-related industries and prevent dust storms that threaten human health and agriculture can be identified and provides the information to evaluate the difficult tradeoffs between direct benefits of consumptive water use and ecosystem services provided by saline lakes.

  11. National Lakes Assessment

    EPA Pesticide Factsheets

    The National Lakes Assessment is a collaborative, statistical survey of the nation's lakes. It is one of four national surveys that EPA and its partners conduct to assess the condition and health of the nation's water resources.

  12. Lake-level history of Lake Michigan for the past 12,000 years: the record from deep lacustrine sediments

    USGS Publications Warehouse

    Colman, Steven M.; Forester, Richard M.; Reynolds, Richard L.; Sweetkind, Donald S.; King, John W.; Gangemi, Paul; Jones, Glenn A.; Keigwin, Loyd D.; Foster, David S.

    1994-01-01

    Collection and analysis of an extensive set of seismic-reflection profiles and cores from southern Lake Michigan have provided new data that document the history of the lake basin for the past 12,000 years. Analyses of the seismic data, together with radiocarbon dating, magnetic, sedimentologic, isotopic, and paleontologic studies of core samples, have allowed us to reconstruct lake-level changes during this recent part of the lake's history.The post-glacial history of lake-level changes in the Lake Michigan basin begins about 11.2 ka with the fall from the high Calumet level, caused by the retreat of the Two Rivers glacier, which had blocked the northern outlet of the lake. This lake-level fall was temporarily reversed by a major influx of water from glacial Lake Agassiz (about 10.6 ka), during which deposition of the distinctive gray Wilmette Bed of the Lake Michigan Formation interrupted deposition of red glaciolacustrine sediment. Lake level then continued to fall, culminating in the opening of the North Bay outlet at about 10.3 ka. During the resulting Chippewa low phase, lake level was about 80 m lower than it is today in the southern basin of Lake Michigan.The rise of the early Holocene lake level, controlled primarily by isostatic rebound of the North Bay outlet, resulted in a prominent, planar, transgressive unconformity that eroded most of the shoreline features below present lake level. Superimposed on this overall rise in lake level, a second influx of water from Lake Agassiz temporarily raised lake levels an unknown amount about 9.1 ka. At about 7 ka, lake level may have fallen below the level of the outlet because of sharply drier climate. Sometime between 6 and 5 ka, the character of the lake changed dramatically, probably due mostly to climatic causes, becoming highly undersaturated with respect to calcium carbonate and returning primary control of lake level to the isostatically rising North Bay outlet. Post-Nipissing (about 5 ka) lake level has

  13. Conifer density within lake catchments predicts fish mercury concentrations in remote subalpine lakes

    USGS Publications Warehouse

    Eagles-Smith, Collin A.; Herring, Garth; Johnson, Branden L.; Graw, Rick

    2016-01-01

    Remote high-elevation lakes represent unique environments for evaluating the bioaccumulation of atmospherically deposited mercury through freshwater food webs, as well as for evaluating the relative importance of mercury loading versus landscape influences on mercury bioaccumulation. The increase in mercury deposition to these systems over the past century, coupled with their limited exposure to direct anthropogenic disturbance make them useful indicators for estimating how changes in mercury emissions may propagate to changes in Hg bioaccumulation and ecological risk. We evaluated mercury concentrations in resident fish from 28 high-elevation, sub-alpine lakes in the Pacific Northwest region of the United States. Fish total mercury (THg) concentrations ranged from 4 to 438 ng/g wet weight, with a geometric mean concentration (±standard error) of 43 ± 2 ng/g ww. Fish THg concentrations were negatively correlated with relative condition factor, indicating that faster growing fish that are in better condition have lower THg concentrations. Across the 28 study lakes, mean THg concentrations of resident salmonid fishes varied as much as 18-fold among lakes. We used a hierarchal statistical approach to evaluate the relative importance of physiological, limnological, and catchment drivers of fish Hg concentrations. Our top statistical model explained 87% of the variability in fish THg concentrations among lakes with four key landscape and limnological variables: catchment conifer density (basal area of conifers within a lake's catchment), lake surface area, aqueous dissolved sulfate, and dissolved organic carbon. Conifer density within a lake's catchment was the most important variable explaining fish THg concentrations across lakes, with THg concentrations differing by more than 400 percent across the forest density spectrum. These results illustrate the importance of landscape characteristics in controlling mercury bioaccumulation in fish.

  14. Conifer density within lake catchments predicts fish mercury concentrations in remote subalpine lakes.

    PubMed

    Eagles-Smith, Collin A; Herring, Garth; Johnson, Branden; Graw, Rick

    2016-05-01

    Remote high-elevation lakes represent unique environments for evaluating the bioaccumulation of atmospherically deposited mercury through freshwater food webs, as well as for evaluating the relative importance of mercury loading versus landscape influences on mercury bioaccumulation. The increase in mercury deposition to these systems over the past century, coupled with their limited exposure to direct anthropogenic disturbance make them useful indicators for estimating how changes in mercury emissions may propagate to changes in Hg bioaccumulation and ecological risk. We evaluated mercury concentrations in resident fish from 28 high-elevation, sub-alpine lakes in the Pacific Northwest region of the United States. Fish total mercury (THg) concentrations ranged from 4 to 438 ng/g wet weight, with a geometric mean concentration (±standard error) of 43 ± 2 ng/g ww. Fish THg concentrations were negatively correlated with relative condition factor, indicating that faster growing fish that are in better condition have lower THg concentrations. Across the 28 study lakes, mean THg concentrations of resident salmonid fishes varied as much as 18-fold among lakes. We used a hierarchal statistical approach to evaluate the relative importance of physiological, limnological, and catchment drivers of fish Hg concentrations. Our top statistical model explained 87% of the variability in fish THg concentrations among lakes with four key landscape and limnological variables: catchment conifer density (basal area of conifers within a lake's catchment), lake surface area, aqueous dissolved sulfate, and dissolved organic carbon. Conifer density within a lake's catchment was the most important variable explaining fish THg concentrations across lakes, with THg concentrations differing by more than 400 percent across the forest density spectrum. These results illustrate the importance of landscape characteristics in controlling mercury bioaccumulation in fish. Published by Elsevier

  15. Lake Tengiz from space

    NASA Image and Video Library

    2017-12-08

    In orbit above the semi-desert grasslands in Kazakhstan, an astronaut aboard the International Space Station spotted one of the few features that stand out. Lake Tengiz is the only large lake (1590 square kilometers, 615 square miles) in northern Kazakhstan. Through white wisps of cloud, the crew member photographed the 50 kilometer-long eastern shore of the lake, with its thin, winding islands and white beaches. The islands and intervening waterways make a rich habitat for birds in this part of Asia. At least 318 species of birds have been identified at the lake; 22 of them are endangered. It is the northernmost habitat of the pink flamingo. The lake system is Kazakhstan’s first UNESCO World Heritage Site, and it has been declared a RAMSAR wetland site of international importance. Part of the richness of area is its complex hydrology. Fresh water enters the system via the Kulanutpes River, so there are small lakes (lower right) full of fresh water. But in this closed basin, the water in the main lake (top) slowly evaporates, becoming salty. Winds stir up bigger waves on the main lake, dispersing sediment and salt and making the water a cloudier and lighter blue-green. (Another astronaut photograph shows the entire lake system, while this story provides more information.) The strange shape of the islands is not easy to interpret. They may be drowned remnants of delta distributaries of the Kulanutpes River. Westerly winds probably have had a smoothing effect on the shorelines, especially in a shallow lake like Tengiz, which is only about 6 meters (20 feet) deep. The lake has an exciting history for people who follow space exploration. In 1976, a Soyuz spacecraft landed in the lake near the north shore (top right). The capsule crashed through the ice and sank during an October snowstorm when temperatures were -22°C (-8°F). Because of low power, the capsule was unheated and the crew was feared lost. It was many hours before the airtight capsule was located and

  16. Lake water quality mapping from Landsat

    NASA Technical Reports Server (NTRS)

    Scherz, J. P.

    1977-01-01

    In the project described remote sensing was used to check the quality of lake waters. The lakes of three Landsat scenes were mapped with the Bendix MDAS multispectral analysis system. From the MDAS color coded maps, the lake with the worst algae problem was easily located. The lake was closely checked, and the presence of 100 cows in the springs which fed the lake could be identified as the pollution source. The laboratory and field work involved in the lake classification project is described.

  17. Assessment of the Great Lakes Marine Renewable Energy Resources: Characterizing Lake Erie Surge, Seiche and Waves

    NASA Astrophysics Data System (ADS)

    Farhadzadeh, A.; Hashemi, M. R.

    2016-02-01

    Lake Erie, the fourth largest in surface area, smallest in volume and shallowest among the Great Lakes is approximately 400 km long and 90 km wide. Short term lake level variations are due to storm surge generated by high winds and moving pressure systems over the lake mainly in the southwest-northeast direction, along the lakes longitudinal axis. The historical wave data from three active offshore buoys shows that significant wave height can exceed 5 m in the eastern and central basins. The long-term lake level data show that storm surge can reach up to 3 m in eastern Lake Erie. Owing its shallow depth, Lake Erie frequently experiences seiching motions, the low frequency oscillations that are initiated by storm surge. The seiches whose first mode of oscillations has a period of nearly 14.2 hours can last from several hours to days. In this study, the Lake Erie potential for power generation, primarily using storm surge and seiche and also waves are assessed. Given the cyclic lake level variations due to storm-induced seiching, a concept similar to that of tidal range development is utilized to assess the potential of storm surge and seiche energy harvesting mechanisms for power generation. In addition, wave energy resources of the Lake is characterized -. To achieve these objectives, the following steps are taken : (1) Frequency of occurrence for extreme storm surge and wave events is determined using extreme value analysis such as Peak-Over-Threshold method for the long-term water level and wave data; (2) Spatial and temporal variations of wave height, storm surge and seiche are characterized. The characterization is carried out using the wave and storm surge outputs from numerical simulation of a number of historical extreme events. The coupled ADCIRC and SWAN model is utilized for the modeling; (3) Assessment of the potentials for marine renewable power generation in Lake Erie is made. The approach can be extended to the other lakes in the Great Lakes region.

  18. Combining lake and watershed characteristics with Landsat TM data for remote estimation of regional lake clarity

    USGS Publications Warehouse

    McCullough, Ian M.; Loftin, Cyndy; Sader, Steven A.

    2012-01-01

    Water clarity is a reliable indicator of lake productivity and an ideal metric of regional water quality. Clarity is an indicator of other water quality variables including chlorophyll-a, total phosphorus and trophic status; however, unlike these metrics, clarity can be accurately and efficiently estimated remotely on a regional scale. Remote sensing is useful in regions containing a large number of lakes that are cost prohibitive to monitor regularly using traditional field methods. Field-assessed lakes generally are easily accessible and may represent a spatially irregular, non-random sample of a region. We developed a remote monitoring program for Maine lakes >8 ha (1511 lakes) to supplement existing field monitoring programs. We combined Landsat 5 Thematic Mapper (TM) and Landsat 7 Enhanced Thematic Mapper Plus (ETM+) brightness values for TM bands 1 (blue) and 3 (red) to estimate water clarity (secchi disk depth) during 1990–2010. Although similar procedures have been applied to Minnesota and Wisconsin lakes, neither state incorporates physical lake variables or watershed characteristics that potentially affect clarity into their models. Average lake depth consistently improved model fitness, and the proportion of wetland area in lake watersheds also explained variability in clarity in some cases. Nine regression models predicted water clarity (R2 = 0.69–0.90) during 1990–2010, with separate models for eastern (TM path 11; four models) and western Maine (TM path 12; five models that captured differences in topography and landscape disturbance. Average absolute difference between model-estimated and observed secchi depth ranged 0.65–1.03 m. Eutrophic and mesotrophic lakes consistently were estimated more accurately than oligotrophic lakes. Our results show that TM bands 1 and 3 can be used to estimate regional lake water clarity outside the Great Lakes Region and that the accuracy of estimates is improved with additional model variables that reflect

  19. Biotic and abiotic factors related to lake herring recruitment in the Wisconsin waters of Lake Superior, 1984-1998

    USGS Publications Warehouse

    Hoff, Michael H.

    2004-01-01

    Lake Superior lake herring (Coregonus artedi) recruitment to 13-14 months of age in the Wisconsin waters of Lake Superior varied by a factor of 5,233 during 1984-1998. Management agencies have sought models that accurately predict recruitment, but no satisfactory model had previously been developed. Lake herring recruitment was modeled to determine which factors most explained recruitment variability. The Ricker stock-recruitment model derived from only the paired stock and recruit data explained 35% of the variability in the recruitment data. The functional relationship that explained the greatest amount of recruitment variation (93%) included lake herring stock size, lake trout (Salvelinus namaycush) population size, slimy sculpin (Cottus cognatus) biomass, the interaction of mean daily wind speed in April (month of hatch) and lake herring stock size, and mean air temperature in April (when lake herring are 12-months old). Model results were interpreted to mean that lake herring recruitment was affected negatively by: slimy sculpin predation on lake herring ova; predation on age-0 lake herring by lake trout; and adult cannibalism on lake herring larvae, which was reduced by increased wind speed. April temperature was the variable that explained the least amount of variability in recruitment, but lake herring recruitment was positively affected by a warm April, which shortened winter and apparently reduced first-winter mortality. Stock size caused compensatory, density-dependent mortality on lake herring recruits. Management efforts appear best targeted at stock size protection, and empirical data implies that stock size in the Wisconsin waters of the lake should be maintained at 2.1-15.0 adults/ha in spring, bottom-trawl surveys.

  20. Childhood cancer survival in Switzerland (1976-2013): Time-trends and predictors.

    PubMed

    Schindler, Matthias; Belle, Fabiën N; Grotzer, Michael A; von der Weid, Nicolas X; Kuehni, Claudia E

    2017-01-01

    Population-based studies on childhood cancer survival are key to monitor progress against cancer and to detect potential differences between regions and other subgroups in the population. We investigated time trends and factors associated with childhood cancer survival on a national level in Switzerland, from 1976 to 2013. We extracted data from the population-based Swiss Childhood Cancer Registry of 5,776 children (age 0-14 years) diagnosed with cancer from 1985 to 2014 in Switzerland. We calculated age-adjusted 5-year survival, defined the annual reduction in risk of death (ARR), and explored associations of survival with clinical and demographic factors. Overall, 5-year survival improved significantly, from 64% in 1976-1983 to 88% in 2004-2013. ARR over the whole period was 4% for all diagnostic groups, greatest for Hodgkin lymphomas (8%), ependymomas (6%), Burkitt's lymphomas (6%) and germ cell tumours (6%). Children treated in hospitals without specialised paediatric cancer centre for leukaemia (HR 12.9), lymphoma (HR 5.0) and neuroblastoma (HR 3.7) were at higher risk of death. In French-speaking Switzerland, risk of death was lower for lymphoma (HR 0.6), CNS tumours (HR 0.7) and neuroblastoma (HR 0.5). Children with migration background had a higher risk of death from all tumours except bone tumours. Childhood cancer survival significantly improved from 1976 to 2013, but there is room for further improvement. Survival rates varied by type of clinical treatment, language region and nationality. All paediatric cancer patients should be referred to a specialised paediatric cancer centre. Further research is needed to intervene and completely eliminate inequalities in survival. © 2016 UICC.

  1. Ecology under lake ice.

    PubMed

    Hampton, Stephanie E; Galloway, Aaron W E; Powers, Stephen M; Ozersky, Ted; Woo, Kara H; Batt, Ryan D; Labou, Stephanie G; O'Reilly, Catherine M; Sharma, Sapna; Lottig, Noah R; Stanley, Emily H; North, Rebecca L; Stockwell, Jason D; Adrian, Rita; Weyhenmeyer, Gesa A; Arvola, Lauri; Baulch, Helen M; Bertani, Isabella; Bowman, Larry L; Carey, Cayelan C; Catalan, Jordi; Colom-Montero, William; Domine, Leah M; Felip, Marisol; Granados, Ignacio; Gries, Corinna; Grossart, Hans-Peter; Haberman, Juta; Haldna, Marina; Hayden, Brian; Higgins, Scott N; Jolley, Jeff C; Kahilainen, Kimmo K; Kaup, Enn; Kehoe, Michael J; MacIntyre, Sally; Mackay, Anson W; Mariash, Heather L; McKay, Robert M; Nixdorf, Brigitte; Nõges, Peeter; Nõges, Tiina; Palmer, Michelle; Pierson, Don C; Post, David M; Pruett, Matthew J; Rautio, Milla; Read, Jordan S; Roberts, Sarah L; Rücker, Jacqueline; Sadro, Steven; Silow, Eugene A; Smith, Derek E; Sterner, Robert W; Swann, George E A; Timofeyev, Maxim A; Toro, Manuel; Twiss, Michael R; Vogt, Richard J; Watson, Susan B; Whiteford, Erika J; Xenopoulos, Marguerite A

    2017-01-01

    Winter conditions are rapidly changing in temperate ecosystems, particularly for those that experience periods of snow and ice cover. Relatively little is known of winter ecology in these systems, due to a historical research focus on summer 'growing seasons'. We executed the first global quantitative synthesis on under-ice lake ecology, including 36 abiotic and biotic variables from 42 research groups and 101 lakes, examining seasonal differences and connections as well as how seasonal differences vary with geophysical factors. Plankton were more abundant under ice than expected; mean winter values were 43.2% of summer values for chlorophyll a, 15.8% of summer phytoplankton biovolume and 25.3% of summer zooplankton density. Dissolved nitrogen concentrations were typically higher during winter, and these differences were exaggerated in smaller lakes. Lake size also influenced winter-summer patterns for dissolved organic carbon (DOC), with higher winter DOC in smaller lakes. At coarse levels of taxonomic aggregation, phytoplankton and zooplankton community composition showed few systematic differences between seasons, although literature suggests that seasonal differences are frequently lake-specific, species-specific, or occur at the level of functional group. Within the subset of lakes that had longer time series, winter influenced the subsequent summer for some nutrient variables and zooplankton biomass. © 2016 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

  2. Methane distribution and transportation in Lake Chaohu: a shallow eutrophic lake in Eastern China

    NASA Astrophysics Data System (ADS)

    Zhang, L.; Shen, Q.

    2016-12-01

    Global warming and eutrophication are two world widely concerned environmental problems. Methane is the second important greenhouse gas, and lake has been proven as a quite important natural source of methane emission. More methane may emit from eutrophic lake due to the higher organic matter deposition in the lake sediment. Lake Chaohu is a large and shallow eutrophic lake in eastern China (N31°25' 31°43', E117°16' 117°05'), with an area of 770 km2 and a mean depth of 2.7 m. To examine methane distribution and transportation in this eutrophic lake, field study across different seasons was carried out with 20 study sites in the lake. Samples from the different water and sediment depth was collected using headspace bottle, and methane content was measured by gas chromatography using a flame ionization detector. The potential methane production in the sediment was examined by an indoor incubation experiment. Methane flux from sediment to the overlying water was calculated by Fick's law, and methane emission from surface to the air was calculated at the same time. The results indicates that more methane accumulated in the water of northwestern bay in this lake, and higher methane release rates was also found at this area. Methane increases gradually with depth in the top 10 cm in sediment cores, then it almost keeps at constant state in the deeper sediment. In the sediment from northwestern bay, more methane content and the higher potential methane production was found compared to the sediment from the east area of this lake.

  3. Treating floodplain lakes of large rivers as study units for variables that vary within lakes; an evaluation using chlorophyll a and inorganic suspended solids data from floodplain lakes of the Upper Mississippi River

    USGS Publications Warehouse

    Gray, B.R.; Rogala, J.R.; Houser, J.N.

    2013-01-01

    Contiguous floodplain lakes ('lakes') have historically been used as study units for comparative studies of limnological variables that vary within lakes. The hierarchical nature of these studies implies that study variables may be correlated within lakes and that covariate associations may differ not only among lakes but also by spatial scale. We evaluated the utility of treating lakes as study units for limnological variables that vary within lakes based on the criteria of important levels of among-lake variation in study variables and the observation of covariate associations that vary among lakes. These concerns were selected, respectively, to ensure that lake signatures were distinguishable from within-lake variation and that lake-scale effects on covariate associations might provide inferences not available by ignoring those effects. Study data represented chlorophyll a (CHL) and inorganic suspended solids (ISS) data from lakes within three reaches of the Upper Mississippi River. Sampling occurred in summer from 1993 through 2005 (except 2003); numbers of lakes per reach varied from 7 to 19, and median lake area varied from 53 to 101 ha. CHL and ISS levels were modelled linearly, with lake, year and lake x year effects treated as random. For all reaches, the proportions of variation in CHL and ISS attributable to differences among lakes (including lake and lake x year effects) were substantial (range: 18%-73%). Finally, among-lake variation in CHL and ISS was strongly associated with covariates and covariate effects that varied by lakes or lake-years (including with vegetation levels and, for CHL, log(ISS)). These findings demonstrate the utility of treating floodplain lakes as study units for the study of limnological variables and the importance of addressing hierarchy within study designs when making inferences from data collected within floodplain lakes.

  4. Preferred temperatures of juvenile lake whitefish

    USGS Publications Warehouse

    Edsall, Thomas A.

    1999-01-01

    Lake whitefish (Coregonus clupeaformis) supported valuable commercial fisheries in all of the Great Lakes until the 1950s to 1960s when their populations collapsed due to overfishing, pollution, and predation by the exotic sea lamprey (Petromyzon marinus). Reduction of these population stresses has permitted significant recovery of the lake whitefish in the upper three Great Lakes since the 1980s, and limited but encouraging recovery is now apparent in Lakes Erie and Ontario. In the present study the thermal preferences of age-0 and age-1 lake whitefish were measured in the laboratory to provide a basis for determining thermal habitat use by juvenile lake whitefish and thermal niche overlap with exotic fishes that might prey on them. Final thermal preferenda of young lake whitefish varied inversely with fish size ranging from 16.8°C for fish averaging 1.9 g to 15.6°C for age-1 fish averaging 3.9 g. Final thermal preferenda were in agreement with the limited published information on temperature selection of juvenile lake whitefish in the laboratory and on thermal habitat use by wild, free-ranging populations in the Great Lakes.

  5. Estimating the volume of Alpine glacial lakes

    NASA Astrophysics Data System (ADS)

    Cook, S. J.; Quincey, D. J.

    2015-09-01

    Supraglacial, moraine-dammed and ice-dammed lakes represent a potential glacial lake outburst flood (GLOF) threat to downstream communities in many mountain regions. This has motivated the development of empirical relationships to predict lake volume given a measurement of lake surface area obtained from satellite imagery. Such relationships are based on the notion that lake depth, area and volume scale predictably. We critically evaluate the performance of these existing empirical relationships by examining a global database of measured glacial lake depths, areas and volumes. Results show that lake area and depth are not always well correlated (r2 = 0.38), and that although lake volume and area are well correlated (r2 = 0.91), there are distinct outliers in the dataset. These outliers represent situations where it may not be appropriate to apply existing empirical relationships to predict lake volume, and include growing supraglacial lakes, glaciers that recede into basins with complex overdeepened morphologies or that have been deepened by intense erosion, and lakes formed where glaciers advance across and block a main trunk valley. We use the compiled dataset to develop a conceptual model of how the volumes of supraglacial ponds and lakes, moraine-dammed lakes and ice-dammed lakes should be expected to evolve with increasing area. Although a large amount of bathymetric data exist for moraine-dammed and ice-dammed lakes, we suggest that further measurements of growing supraglacial ponds and lakes are needed to better understand their development.

  6. Benthic-planktonic coupling, regime shifts, and whole-lake primary production in shallow lakes.

    PubMed

    Genkai-Kato, Motomi; Vadeboncoeur, Yvonne; Liboriussen, Lone; Jeppesen, Erik

    2012-03-01

    Alternative stable states in shallow lakes are typically characterized by submerged macrophyte (clear-water state) or phytoplankton (turbid state) dominance. However, a clear-water state may occur in eutrophic lakes even when macrophytes are absent. To test whether sediment algae could cause a regime shift in the absence of macrophytes, we developed a model of benthic (periphyton) and planktonic (phytoplankton) primary production using parameters derived from a shallow macrophyte-free lake that shifted from a turbid to a clear-water state following fish removal (biomanipulation). The model includes a negative feedback effect of periphyton on phosphorus (P) release from sediments. This in turn induces a positive feedback between phytoplankton production and P release. Scenarios incorporating a gradient of external P loading rates revealed that (1) periphyton and phytoplankton both contributed substantially to whole-lake production over a broad range of external P loading in a clear-water state; (2) during the clear-water state, the loss of benthic production was gradually replaced by phytoplankton production, leaving whole-lake production largely unchanged; (3) the responses of lakes to biomanipulation and increased external P loading were both dependent on lake morphometry; and (4) the capacity of periphyton to buffer the effects of increased external P loading and maintain a clear-water state was highly sensitive to relationships between light availability at the sediment surface and the of P release. Our model suggests a mechanism for the persistence of alternative states in shallow macrophyte-free lakes and demonstrates that regime shifts may trigger profound changes in ecosystem structure and function.

  7. Population dynamics of Lake Ontario lake trout during 1985-2007

    USGS Publications Warehouse

    Brenden, Travis O.; Bence, James R.; Lantry, Brian F.; Lantry, Jana R.; Schaner, Ted

    2011-01-01

    Lake trout Salvelinus namaycush were extirpated from Lake Ontario circa 1950 owing to commercial and recreational fishing, predation by sea lampreys Petromyzon marinus, and habitat degradation. Since the 1970s, substantial efforts have been devoted to reestablishing a self-sustaining population through stocking, sea lamprey control, and harvest reduction. Although a stocking-supported population has been established, only limited natural reproduction has been detected. Since the 1990s, surveys have indicated a continuing decline in overall abundance despite fairly static stocking levels. We constructed a statistical catch-at-age model to describe the dynamics of Lake Ontario lake trout from 1985 to 2007 and explore what factor(s) could be causing the declines in abundance. Model estimates indicated that abundance had declined by approximately 76% since 1985. The factor that appeared most responsible for this was an increase in age-1 natural mortality rates from approximately 0.9 to 2.5 between 1985 and 2002. The largest source of mortality for age-2 and older fish was sea lamprey predation, followed by natural and recreational fishing mortality. Exploitation was low, harvest levels being uncertain and categorized by length rather than age. Accurate predictions of fishery harvest and survey catch per unit effort were obtained despite low harvest levels by using atypical data (e.g., numbers stocked as an absolute measure of recruitment) and a flexible modeling approach. Flexible approaches such as this might allow similar assessments for a wide range of lightly exploited stocks. The mechanisms responsible for declining age-1 lake trout survival are unknown, but the declines were coincident with an increase in the proportion of stocked fish that were of the Seneca strain and a decrease in the overall stocking rate. It is possible that earlier studies suggesting that Seneca strain lake trout would be successful in Lake Ontario are no longer applicable given the large

  8. The Great Lakes

    EPA Pesticide Factsheets

    The Great Lakes form the largest surface freshwater system on Earth. The U.S. and Canada work together to restore and protect the environment in the Great Lakes Basin. Top issues include contaminated sediments, water quality and invasive species.

  9. Changes in depth occupied by Great Lakes lake whitefish populations and the influence of survey design

    USGS Publications Warehouse

    Rennie, Michael D.; Weidel, Brian C.; Claramunt, Randall M.; Dunlob, Erin S.

    2015-01-01

    Understanding fish habitat use is important in determining conditions that ultimately affect fish energetics, growth and reproduction. Great Lakes lake whitefish (Coregonus clupeaformis) have demonstrated dramatic changes in growth and life history traits since the appearance of dreissenid mussels in the Great Lakes, but the role of habitat occupancy in driving these changes is poorly understood. To better understand temporal changes in lake whitefish depth of capture (Dw), we compiled a database of fishery-independent surveys representing multiple populations across all five Laurentian Great Lakes. By demonstrating the importance of survey design in estimating Dw, we describe a novel method for detecting survey-based bias in Dw and removing potentially biased data. Using unbiased Dw estimates, we show clear differences in the pattern and timing of changes in lake whitefish Dw between our reference sites (Lake Superior) and those that have experienced significant benthic food web changes (lakes Michigan, Huron, Erie and Ontario). Lake whitefish Dw in Lake Superior tended to gradually shift to shallower waters, but changed rapidly in other locations coincident with dreissenid establishment and declines in Diporeia densities. Almost all lake whitefish populations that were exposed to dreissenids demonstrated deeper Dw following benthic food web change, though a subset of these populations subsequently shifted to more shallow depths. In some cases in lakes Huron and Ontario, shifts towards more shallow Dw are occurring well after documented Diporeia collapse, suggesting the role of other drivers such as habitat availability or reliance on alternative prey sources.

  10. Changes in consumption by alewives and lake whitefish after dreissenid mussel invasions in Lakes Michigan and Huron

    USGS Publications Warehouse

    Pothoven, S.A.; Madenjian, C.P.

    2008-01-01

    Growth of alewives Alosa pseudoharengus and lake whitefish Coregonus clupeaformis has declined since the arrival and spread of dreissenid mussels in Lakes Michigan and Huron. Alewives are the main forage for the salmonids in Lake Michigan, and lake whitefish are the most important commercial species in both lakes. Bioenergetics modeling was used to determine consumption by the average individual fish before and after the dreissenid invasion and to provide insight into the invasion's effects on fish growth and food web dynamics. Alewives feed on both Zooplankton and benthic macroinvertebrates, and lake whitefish are benthivores. Annual consumption of zooplankton by an average alewife in Lake Michigan was 37% lower and consumption of benthic macroinvertebrates (amphipods Diporeia spp., opossum shrimp Mysis relicta, and Chironomidae) was 19% lower during the postinvasion period (1995-2005) than during the preinvasion period (1983-1994). Reduced consumption by alewives corresponded with reduced alewife growth. In Lakes Michigan and Huron, consumption of nonmollusk macroinvertebrates (Diporeia spp., opossum shrimp, Chironomidae) by the average lake whitefish was 46-96% lower and consumption of mollusks (mainly dreissenids and gastropods) was 2-5 times greater during the postinvasion period than during the preinvasion period. Even though total food consumption by lake whitefish did not differ between the two periods in Lake Huron or the Southern Management Unit in Lake Michigan, postinvasion weight at age was at least 38% lower than preinvasion weight at age. Under the current postinvasion diet regime, consumption by lake whitefish would have to increase by up to 122% to achieve preinvasion growth rates. ?? Copyright by the American Fisheries Society 2008.

  11. WINCHESTER LAKE, LEWIS COUNTY, IDAHO - CLEAN LAKES PHASE II IMPLEMENTATION AND RESTORATION PROJECT, 1996

    EPA Science Inventory

    Winchester Lake, Idaho (17060306) is an 85 acre recreation site located approximately 30 miles southeast of Lewiston. The lake has been involved in the U.S. EPA Clean Lakes Program since 1988. The Phase I Diagnostic and Feasibility Study, completed in February 1990, identified t...

  12. Historical changes to Lake Washington and route of the Lake Washington Ship Canal, King County, Washington

    USGS Publications Warehouse

    Chrzastowski, Michael J.

    1983-01-01

    Lake Washington, in the midst of the greater Seattle metropolitan area of the Puget Sound region (fig. 1), is an exceptional commercial, recreational, and esthetic resource for the region . In the past 130 years, Lake Washington has been changed from a " wild " lake in a wilderness setting to a regulated lake surrounded by a growing metropolis--a transformation that provides an unusual opportunity to study changes to a lake's shoreline and hydrologic characteristics -resulting from urbanization.

  13. Residues of DDT in lake trout (Salvelinus namaycush) and coho salmon (Oncorhynchus kisutch) from the Great Lakes

    USGS Publications Warehouse

    Reinert, Robert E.; Bergman, Harold L.

    1974-01-01

    Concentrations of DDT residues were higher in lake trout (Salvelinus namaycush) from southern Lake Michigan in 1966–70 (average 18.1 ppm in fish 558–684 mm long) than in lake trout of the same size-class from Lake Superior in 1968–69 (4.4 ppm), and higher in adult coho salmon (Oncorhynchus kisutch) from Lake Michigan in 1968–71 (averages for different year-classes, 9.9–14.0 ppm) than in those from Lake Erie in 1969 (2.2 ppm). Residues were significantly higher in lake trout from southern Lake Michigan than in those from the northern part of the lake. In lakes Michigan and Superior, the levels increased with length of fish and percentage oil. In Lake Michigan coho salmon, the residues remained nearly stable (2–4 ppm) from September of the 1st yr of lake residence through May or early June of the 2nd yr, but increased three to four times in the next 3 mo. Residues in Lake Erie coho salmon did not increase during this period, which preceded the spawning season. Although the concentrations of total residues in whole, maturing Lake Michigan coho salmon remained unchanged from August 1968 until near the end of the spawning season in January 1969, the residues were redistributed in the tissues of the spawning-run fish; concentrations in the loin and brain were markedly higher in January than in August. This relocation of DDT residues accompanied a marked decrease in the percentage of oil in the fish, from 13.2 in August to 2.8 in January. Concentrations of residues were relatively high in eggs of both lake trout (4.6 ppm) and coho salmon (7.4–10.2 ppm) from Lake Michigan. The percentage composition of the residues (p,p′DDE, o,p′/DDT, p,p′DDT, and p,p′DDT) did not differ significantly with life stage, size, age, or locality, or date of collection of lake trout or coho salmon.

  14. Survival of hatchery-reared lake trout stocked near shore and off shore in Lake Ontario

    USGS Publications Warehouse

    Elrod, Joseph H.

    1997-01-01

    Establishing a stock of mature, hatchery-reared fish is necessary to restore a self-sustaining population of lake trout Salvelinus namaycush in Lake Ontario. Stocking fish off shore rather than near shore to reduce predation on these fish by large lake trout or piscivorous birds may enhance survival of hatchery-reared fish and accelerate establishment of a population of adults. Results of an earlier study did not support routinely stocking fish off shore by helicopter in Lake Ontario, but stresses associated with helicopter stocking suggested another method of transporting fish off shore might enhance survival. I conducted this study to determine whether stocking lake trout off shore by barge would enhance first-year survival. Two lots of yearling lake trout were stocked at each of four locations in Lake Ontario in May 1992. One lot was stocked from shore, and an identical lot was transported by barge 3.4–10.4 km off shore of nearshore locations and stocked in water 46–52 m deep. Fish were recovered during trawl, gillnet, and creel surveys in 1992–1996. First-year survival of lake trout stocked off shore tended to be better than that of fish stocked near shore. Predation by double-crested cormorantsPhalacrocorax auritus likely affected survival of fish stocked near shore at two locations, 7 and 37 km, respectively, from a nesting colony of 5,443 pairs of double-crested cormorants. Predation by large lake trout remains a viable hypothesis, which explains, at least partially, lower survival of lake trout stocked near shore at two other locations. Stocking lake trout off shore of traditional nearshore stocking sites likely will enhance first-year survival of hatchery-reared fish and promote accumulation of an adult population, especially for those occassions where nearshore stocking locations are near nesting colonies of double-crested cormorants.

  15. Climate of a high altitude lake basin and lake-atmosphere interactions - observations and atmospheric modelling

    NASA Astrophysics Data System (ADS)

    Maussion, F.; Kropacek, J.; Finkelnburg, R.; Scherer, D.

    2012-04-01

    Large lakes and inland water bodies have a significant influence on their local climate. The hydrometeorological effect of inland water bodies is varying greatly between seasons, years and contrasting climatic conditions. It is generally hypothesised that the cool air above the lake will inhibit convection in summer; conversely, the relatively warm lake in late-autumn will initiate convective instability that may generate strong snowfalls. In this study we focus on the lake Nam Co (2'000 sq.km, 4700 m a.s.l). Located in a transition zone between the continental climate of Central Asia and the Indian Monsoon system, the Nam Co lake is covered by ice from mid-January to end of April and reaches surface temperatures of 13 °C in summer. We address three main research questions: (i) what is the influence of the Nam Co lake on local meteorological variables over the course of the year, (ii) what is the impact of the timing of the lake freezing on late-autumn and winter precipitation fields and (iii) how will the influence of the lake evolve in the context of a changing climate? In order to answer these questions, we combine satellite observations of lake surface temperatures from the ARC-Lake product and atmospheric modelling using the WRF model. The spatio-temporal variability of temperature, wind and precipitation fields during the last decade are analyzed using high-resolution (up to 2 km) simulations. The positive impact of the assimilation of the lake surface temperatures for the initialization of the model is analysed and discussed, as well as the combined influences of the large scale (westerlies, monsoon) and local (orographic) forcings. Our results are of relevance for any regional climate or hydrological modelling study and bring new insights in our understanding of the complex hydrometeorological processes taking place on the Tibetan Plateau.

  16. Glacier, Glacial Lake, and Ecological Response Dynamics of the Imja Glacier-Lake-Moraine System, Nepal

    NASA Astrophysics Data System (ADS)

    Kargel, J. S.; Shugar, D. H.; Leonard, G. J.; Haritashya, U. K.; Harrison, S.; Shrestha, A. B.; Mool, P. K.; Karki, A.; Regmi, D.

    2016-12-01

    Glacier response dynamics—involving a host of processes—produce a sequence of short- to long-term delayed responses to any step-wise, oscillating, or continuous trending climatic perturbation. We present analysis of Imja Lake, Nepal and examine its thinning and retreat and a sequence of the detachment of tributaries; the inception and growth of Imja Lake and concomitant glacier retreat, thinning, and stagnation, and relationships to lake dynamics; the response dynamics of the ice-cored moraine; the development of the local ecosystem; prediction of short-term dynamical responses to lake lowering (glacier lake outburst flood—GLOF—mitigation); and prospects for coming decades. The evolution of this glacier system provides a case study by which the global record of GLOFs can be assessed in terms of climate change attribution. We define three response times: glacier dynamical response time (for glacier retreat, thinning, and slowing of ice flow), limnological response time (lake growth), and GLOF trigger time (for a variety of hazardous trigger events). Lake lowering (to be completed in August 2016; see AGU abstract by D. Regmi et al.) will reduce hazards, but we expect that the elongation of the lake and retreat of the glacier will continue for decades after a pause in 2016-2017. The narrowing of the moraine dam due to thaw degradation of the ice-cored end moraine means that the hazard due to Imja Lake will soon again increase. We examine both long-term response dynamics, and two aspects of Himalayan glaciers that have very rapid responses: the area of Imja Lake fluctuates seasonally and even with subseasonal weather variations in response to changes in lake temperature and glacier meltback; and as known from other studies, glacier flow speed can vary between years and even on shorter timescales. The long-term development and stabilization of glacial moraines and small lacustrine plains in drained lake basins impacts the development of local ecosystems

  17. Great Lakes, No Clouds

    NASA Image and Video Library

    2017-12-08

    NASA image acquired August 28, 2010 Late August 2010 provided a rare satellite view of a cloudless summer day over the entire Great Lakes region. North Americans trying to sneak in a Labor Day weekend getaway on the lakes were hoping for more of the same. The Great Lakes comprise the largest collective body of fresh water on the planet, containing roughly 18 percent of Earth's supply. Only the polar ice caps contain more fresh water. The region around the Great Lakes basin is home to more than 10 percent of the population of the United States and 25 percent of the population of Canada. Many of those people have tried to escape record heat this summer by visiting the lakes. What they found, according to The Hamilton Spectator, was record-breaking water temperatures fueled by record-breaking air temperatures in the spring and summer. By mid-August, the waters of Lake Superior were 6 to 8°C (11 to 14°F) above normal. Lake Michigan set records at about 4°C (7°F) above normal. The other three Great Lakes – Huron, Erie, and Ontario -- were above normal temperatures, though no records were set. The image was gathered by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite at 1:30 p.m. Central Daylight Time (18:30 UTC) on August 28. Open water appears blue or nearly black. The pale blue and green swirls near the coasts are likely caused by algae or phytoplankton blooms, or by calcium carbonate (chalk) from the lake floor. The sweltering summer temperatures have produced an unprecedented bloom of toxic blue-green algae in western Lake Erie, according to the Cleveland Plain Dealer. NASA image by Jeff Schmaltz, MODIS Rapid Response Team, Goddard Space Flight Center. Caption by Mike Carlowicz. Instrument: Aqua - MODIS Click here to see more images from NASA Goddard’s Earth Observatory NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft

  18. Expanding models of lake trophic state to predict cyanobacteria in lakes

    EPA Science Inventory

    Background/Question/Methods: Cyanobacteria are a primary taxonomic group associated with harmful algal blooms in lakes. Understanding the drivers of cyanobacteria presence has important implications for lake management and for the protection of human and ecosystem health. Chlor...

  19. Causes of declining survival of lake trout stocked in U.S. waters of Lake Superior in 1963-1986

    USGS Publications Warehouse

    Hansen, Michael J.; Ebener, Mark P.; Schorfhaar, Richard G.; Schram, Stephen T.; Schreiner, Donald R.; Selgeby, James H.; Taylor, William W.

    1996-01-01

    Survival of the 1963-1982 year-classes of stocked yearling lake trout Salvelinus namaycush declined significantly over time in Lake Superior. To investigate possible causes of this decline, a Ricker model of stock-recruitment was used to describe the catch per effort (CPE) of age-7 stocked lake trout in the Michigan, Minnesota, and Wisconsin waters of Lake Superior as functions of the numbers of yearlings stocked 6 years earlier (an index of density dependence), the density (CPE) of wild adult lake trout (an index of predation), and large-mesh (a?Y 114-mm stretch-measure) gill-net fishing effort (an index of fishing mortality). Declining CPE of stocked lake trout in Michigan and Wisconsin was significantly associated with increasing large-mesh gillnet fishing effort. Declining CPE of stocked lake trout in Minnesota was significantly associated with increasing density of wild lake trout. Declining survival of stocked lake trout may therefore have been caused by increased mortality in large-mesh gill-net fisheries in Michigan and Wisconsin, and by predation by wild lake trout that recently recolonized the Minnesota area. We recommend that experimental management be pursued to determine the relative importance of large-mesh gillnet fishing effort and of predation by wild lake trout on the survival of stocked lake trout in U.S. waters of Lake Superior.

  20. Seasonal food of juvenile lake trout in U.S. waters of Lake Ontario

    USGS Publications Warehouse

    Elrod, Joseph H.

    1983-01-01

    Stomach contents of 3,554 lake trout (Salvelinus namaycush), 100 to 449 mm in total length, captured with bottom trawls during April through October 1978–81 along the south shore of Lake Ontario were examined. Invertebrates appeared to be an important food of lake trout less than 200 mm long but were only occasionally eaten by larger fish. For all seasons and size groups of juvenile lake trout combined, the slimy sculpin (Cottus cognatus) was the principal forage fish, making up 42% (by weight) of identifiable fish remains. Young-of-the-year slimy sculpins were a major food of recently stocked yearling lake trout during July through October. Alewives (Alosa pseudoharengus) were the principal forage during April and May, and made up 28% (by weight) of the identifiable fish remains. They were rarely eaten during July and August, however, when lake trout remained in the hypolimnion and alewives were above it. Over 99% of the alewives eaten from April through August were yearlings and over 99% eaten during October were young-of-the-year. Rainbow smelt (Osmerus mordax) were the primary forage during July and August, but contributed only a small part of the diet during other seasons; overall, they made up 25% of identifiable fish remains. Johnny darters (Etheostoma nigrum) made up 4% of identifiable fish remains and were most common in stomachs of small lake trout during October.

  1. Suppression of invasive lake trout in an isolated backcountry lake in Glacier National Park

    USGS Publications Warehouse

    Fredenberg, C. R.; Muhlfeld, Clint C.; Guy, Christopher S.; D'Angelo, Vincent S.; Downs, Christopher C.; Syslo, John M.

    2017-01-01

    Fisheries managers have implemented suppression programmes to control non-native lake trout, Salvelinus namaycush (Walbaum), in several lakes throughout the western United States. This study determined the feasibility of experimentally suppressing lake trout using gillnets in an isolated backcountry lake in Glacier National Park, Montana, USA, for the conservation of threatened bull trout, Salvelinus confluentus (Suckley). The demographics of the lake trout population during suppression (2009–2013) were described, and those data were used to assess the effects of suppression scenarios on population growth rate (λ) using an age-structured population model. Model simulations indicated that the population was growing exponentially (λ = 1.23, 95% CI: 1.16–1.28) prior to suppression. However, suppression resulted in declining λ(0.61–0.79) for lake trout, which was concomitant with stable bull trout adult abundances. Continued suppression at or above observed exploitation levels is needed to ensure continued population declines.

  2. Lake Chad, Chad, Africa

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Hydrologic and ecologic changes in the Lake Chad Basin are shown in this Oct 1992 photograph. In space photo documentation, Lake Chad was at its greatest area extent (25,000 sq. km.) during Gemini 9 in June 1966 (see S66-38444). Its reduction during the severe droughts from 1968 to 1974 was first noted during Skylab (1973-1974). After the drought began again in 1982, the lake reached its minimum extent (1,450 sq. km.) in Space Shuttle photographs taken in 1984 and 1985. In this STS-52 photograph, Lake Chad has begun to recover. The area of the open water and interdunal impoundments in the southern basin (the Chari River Basin) is estimated to be 1,900 to 2100 sq. km. Note the green vegetation in the valley of the K'Yobe flow has wetted the northern lake basin for the first time in several years. There is evidence of biomass burning south of the K'Yobe Delta and in the vegetated interdunal areas near the dike in the center of the lake. Also note the dark 'Green Line' of the Sahel (the g

  3. Acrylamide in a fried potato dish (rösti) from restaurants in Zurich, Switzerland.

    PubMed

    McCombie, Gregor; Biedermann, Maurus; Biedermann-Brem, Sandra; Suter, Gaby; Eicher, Angela; Pfefferle, Anton

    2016-01-01

    Rösti, a fried potato product, is a large contributor to acrylamide exposure locally in Switzerland. A survey of 55 dishes prepared by 51 restaurants in the city of Zurich showed that the average rösti contained 702 µg/kg acrylamide. By analysing the content of reducing sugars in the potatoes used for frying, it is shown that with simple measures, the exposure to acrylamide could easily be reduced by factor 2 or more, while even improving the culinary experience. Though rösti is a typical dish in the German-speaking areas in Switzerland, the result may be of general interest for fried potato products which are popular in large areas of Central Europe.

  4. 78 FR 11094 - Safety Zone; Lake Worth Dredge Operations, Lake Worth Inlet; West Palm Beach, FL

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-15

    ... 1625-AA00 Safety Zone; Lake Worth Dredge Operations, Lake Worth Inlet; West Palm Beach, FL AGENCY... safety zone on Lake Worth Inlet, West Palm Beach, Florida, to provide for the safety of life and vessels..., dredging operations will be conducted on Lake Worth Inlet in West Palm Beach, Florida. These operations...

  5. Ohio Lake Erie Commission Homepage

    Science.gov Websites

    view the Lake Erie Protection & Restoration Plan 2016. Phosphorus Task Force Click here to see the Ohio Lake Erie Phosphorus Task Force II Final Report 2013. About the Lake Erie Commission The role of

  6. Early Holocene Great Salt Lake

    USGS Publications Warehouse

    Oviatt, Charles G.; Madsen, David B.; Miller, David; Thompson, Robert S.; McGeehin, John P.

    2015-01-01

    Shorelines and surficial deposits (including buried forest-floor mats and organic-rich wetland sediments) show that Great Salt Lake did not rise higher than modern lake levels during the earliest Holocene (11.5–10.2 cal ka BP; 10–9 14C ka BP). During that period, finely laminated, organic-rich muds (sapropel) containing brine-shrimp cysts and pellets and interbedded sodium-sulfate salts were deposited on the lake floor. Sapropel deposition was probably caused by stratification of the water column — a freshwater cap possibly was formed by groundwater, which had been stored in upland aquifers during the immediately preceding late-Pleistocene deep-lake cycle (Lake Bonneville), and was actively discharging on the basin floor. A climate characterized by low precipitation and runoff, combined with local areas of groundwater discharge in piedmont settings, could explain the apparent conflict between evidence for a shallow lake (a dry climate) and previously published interpretations for a moist climate in the Great Salt Lake basin of the eastern Great Basin.

  7. Estimating the volume of Alpine glacial lakes

    NASA Astrophysics Data System (ADS)

    Cook, S. J.; Quincey, D. J.

    2015-12-01

    Supraglacial, moraine-dammed and ice-dammed lakes represent a potential glacial lake outburst flood (GLOF) threat to downstream communities in many mountain regions. This has motivated the development of empirical relationships to predict lake volume given a measurement of lake surface area obtained from satellite imagery. Such relationships are based on the notion that lake depth, area and volume scale predictably. We critically evaluate the performance of these existing empirical relationships by examining a global database of glacial lake depths, areas and volumes. Results show that lake area and depth are not always well correlated (r2 = 0.38) and that although lake volume and area are well correlated (r2 = 0.91), and indeed are auto-correlated, there are distinct outliers in the data set. These outliers represent situations where it may not be appropriate to apply existing empirical relationships to predict lake volume and include growing supraglacial lakes, glaciers that recede into basins with complex overdeepened morphologies or that have been deepened by intense erosion and lakes formed where glaciers advance across and block a main trunk valley. We use the compiled data set to develop a conceptual model of how the volumes of supraglacial ponds and lakes, moraine-dammed lakes and ice-dammed lakes should be expected to evolve with increasing area. Although a large amount of bathymetric data exist for moraine-dammed and ice-dammed lakes, we suggest that further measurements of growing supraglacial ponds and lakes are needed to better understand their development.

  8. Hydrology of Central Florida Lakes - A Primer

    USGS Publications Warehouse

    Schiffer, Donna M.

    1998-01-01

    INTRODUCTION Lakes are among the most valued natural resources of central Florida. The landscape of central Florida is riddled with lakeswhen viewed from the air, it almost seems there is more water than land. Florida has more naturally formed lakes than other southeastern States, where many lakes are created by building dams across streams. The abundance of lakes on the Florida peninsula is a result of the geology and geologic history of the State. An estimated 7,800 lakes in Florida are greater than 1 acre in surface area. Of these, 35 percent are located in just four counties (fig. 1): Lake, Orange, Osceola, and Polk (Hughes, 1974b). Lakes add to the aesthetic and commercial value of the area and are used by many residents and visitors for fishing, boating, swimming, and other types of outdoor recreation. Lakes also are used for other purposes such as irrigation, flood control, water supply, and navigation. Residents and visitors commonly ask questions such as Whyare there so many lakes here?, Why is my lake drying up (or flooding)?, or Is my lake spring-fed? These questions indicate that the basic hydrology of lakes and the interaction of lakes with ground water and surface water are not well understood by the general population. Because of the importance of lakes to residents of central Florida and the many questions and misconceptions about lakes, this primer was prepared by the U.S. Geological Survey (USGS) in cooperation with the St. Johns River Water Management District and the South Florida Water Management District. The USGS has been collecting hydrologic data in central Florida since the 1920s, obtaining valuable information that has been used to better understand the hydrology of the water resources of central Florida, including lakes. In addition to data collection, as of 1994, the USGS had published 66 reports and maps on central Florida lakes (Garcia and Hoy, 1995). The main purpose of this primer is to describe the hydrology of lakes in central

  9. Limnology of selected lakes in Ohio, 1975

    USGS Publications Warehouse

    Tobin, Robert L.; Youger, John D.

    1977-01-01

    Water-quality reconnaissance by the U.S. Geological Survey and Ohio Environmental Protection Agency, to evaluate the status of Ohio's lakes and reservoirs was begun in 1975 with studies of 17 lakes. Spring and summer data collections for each lake included: profile measurements of temperature, dissolved oxygen, pH, and specific conductance; field and laboratory analyses of physical, biological, chemical organic characteristics; (nutrient), and concentrations of major and minor chemical constituents from composites of the water column; and physical and chemical data from major inflows.Light penetration (secchi disk) ranged from 9.4 feet (2.9 meters) in Lake Hope to 0.4 feet (0.1 meter) in Acton Lake. Seasonal thermal stratification or stability is shown for 10 lakes deeper than 15 feet (4.6 meters). Unstable or modified temperature profiles were observed in shallow lakes (depths less than 15 feet) or lakes controlled through subsurface release valves.Dissolved oxygen saturation ranged from 229 percent (20.8 milligrams per liter) in the epilimnion of Paint Creek Lake to zero in the bottom waters of all thermally stabilized lakes. Marked chemical and physical differences and nutrient uptake and recycling developed within different thermal strata. Anaerobic zones were frequently characterized by hydrogen sulfide and ammonia.Calcium was the dominant or codominant cation, and bicarbonate and(or) sulfate were the major anions in all lakes sampled. Only Hope and Vesuvius Lakes had soft water (hardness less than 61 milligrams per liter as CaCO3 ), and both lakes were further characterized by low pH (less than 7.0). Specific conductance ranged from 510 micromhos (Deer Creek and Salt Fork Lakes) to 128 micromhos (Lake Hope). Pesticide residues were detected in Acton Lake, and concentrations of one or more trace metals were at or above Ohio Environmental Protection Agency recommended limits in 11 lakes.Fecal coliform colony counts were below 400 colonies per 100 milliliters in

  10. 33 CFR 162.136 - Connecting waters from Lake Huron to Lake Erie; anchorage grounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... to Lake Erie; anchorage grounds. 162.136 Section 162.136 Navigation and Navigable Waters COAST GUARD... REGULATIONS § 162.136 Connecting waters from Lake Huron to Lake Erie; anchorage grounds. (a) In the Detroit...: There is an authorized anchorage in Canadian waters just above Fighting Island and an authorized...

  11. 33 CFR 162.136 - Connecting waters from Lake Huron to Lake Erie; anchorage grounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... to Lake Erie; anchorage grounds. 162.136 Section 162.136 Navigation and Navigable Waters COAST GUARD... REGULATIONS § 162.136 Connecting waters from Lake Huron to Lake Erie; anchorage grounds. (a) In the Detroit...: There is an authorized anchorage in Canadian waters just above Fighting Island and an authorized...

  12. 33 CFR 162.136 - Connecting waters from Lake Huron to Lake Erie; anchorage grounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... to Lake Erie; anchorage grounds. 162.136 Section 162.136 Navigation and Navigable Waters COAST GUARD... REGULATIONS § 162.136 Connecting waters from Lake Huron to Lake Erie; anchorage grounds. (a) In the Detroit...: There is an authorized anchorage in Canadian waters just above Fighting Island and an authorized...

  13. 33 CFR 162.136 - Connecting waters from Lake Huron to Lake Erie; anchorage grounds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... to Lake Erie; anchorage grounds. 162.136 Section 162.136 Navigation and Navigable Waters COAST GUARD... REGULATIONS § 162.136 Connecting waters from Lake Huron to Lake Erie; anchorage grounds. (a) In the Detroit...: There is an authorized anchorage in Canadian waters just above Fighting Island and an authorized...

  14. [Swiss Research Agenda for Nursing (SRAN): the development of an agenda for clinical nursing research in Switzerland].

    PubMed

    Imhof, Lorenz; Abderhalden, Christoph; Cignacco, Eva; Eicher, Manuela; Mahrer-Imhof, Romy; Schubert, Maria; Shaha, Maya

    2008-12-01

    In many Anglo-Saxon and North European countries nursing research agendas have been developed to address priorities in nursing research in accordance with a nationally defined health policy. In Switzerland, due to lack of a nationwide governmental health policy, co-ordination of nursing research so far was scarce. The "Swiss Research Agenda for Nursing (SRAN)" project developed an agenda for clinical nursing research between 2005 and 2007. Based on literature reviews, expert panels and a national survey a project team formulated an agenda which passed a consensus conference. The agenda recommends aspects that should lead research and defines seven research priorities for nursing in Switzerland for the time between 2007 and 2017. Nursing research should prioritize to investigate 1) the effectiveness of nursing interventions; 2) the influences of service adaptations in a changing health care system; 3) the phenomena in patients requiring nursing care; 4) the influence of the work environment on the quality of nursing care; 5) the functioning of family and social systems; 6) varieties of life circumstances and their integration; and 7) the implementation of ethical principles in nursing. Written in German and French, the Swiss Research Agenda for Nursing for the first time formulates priorities for nursing research in Switzerland and can be used for strategic discussions. As a next step, the development of an action plan to enhance nursing research will take place in Switzerland.

  15. [Swiss Research Agenda for Nursing (SRAN): the development of an agenda for clinical nursing research in Switzerland].

    PubMed

    Imhof, Lorenz; Abderhalden, Christoph; Cignacco, Eva; Eicher, Manuela; Mahrer-Imhof, Romy; Schubert, Maria; Shaha, Maya

    2008-08-01

    In many Anglo-Saxon and North European countries nursing research agendas have been developed to address priorities in nursing research in accordance with a nationally defined health policy. In Switzerland, due to lack of a nationwide governmental health policy, co-ordination of nursing research so far was scarce. The "Swiss Research Agenda for Nursing (SRAN)" project developed an agenda for clinical nursing research between 2005 and 2007. Based on literature reviews, expert panels and a national survey a project team formulated an agenda which passed a consensus conference. The agenda recommends aspects that should lead research and defines seven research priorities for nursing in Switzerland for the time between 2007 and 2017. Nursing research should prioritize to investigate 1) the effectiveness of nursing interventions; 2) the influences of service adaptations in a changing health care system; 3) the phenomena in patients requiring nursing care; 4) the influence of the work environment on the quality of nursing care; 5) the functioning of family and social systems; 6) varieties of life circumstances and their integration; and 7) the implementation of ethical principles in nursing. Written in German and French, the Swiss Research Agenda for Nursing for the first time formulates priorities for nursing research in Switzerland and can be used for strategic discussions. As a next step, the development of an action plan to enhance nursing research will take place in Switzerland.

  16. Climate Change Toolkit-Case study: Switzerland

    NASA Astrophysics Data System (ADS)

    Ashraf Vaghefi, Saeid

    2017-04-01

    This paper describes the development of a Climate Change Toolkit (CCT) to rapidly perform tasks needed in a climate change study. CCT consists of five modules: data extraction, global climate data management, bias correction, spatial interpolation, and critical consecutive day analyzer to calculate extreme events. CCT is linked to an archive of big dataset consisting of daily global historic (CRU, 1970-2005), and global GCM data (1960-2099) from 5 models and 4 carbon scenarios. Application of CCT in Switzerland using ensemble results of scenario RCP8.5 showed an increase in Max temperature, and a wide change in precipitation. Frequency of dry periods will likely increase. The frequency of wet periods suggests higher risk of flooding in the country.

  17. Lake water quality mapping from LANDSAT

    NASA Technical Reports Server (NTRS)

    Scherz, J. P.

    1977-01-01

    The lakes in three LANDSAT scenes were mapped by the Bendix MDAS multispectral analysis system. Field checking the maps by three separate individuals revealed approximately 90-95% correct classification for the lake categories selected. Variations between observers was about 5%. From the MDAS color coded maps the lake with the worst algae problem was easily located. This lake was closely checked and a pollution source of 100 cows was found in the springs which fed this lake. The theory, lab work and field work which made it possible for this demonstration project to be a practical lake classification procedure are presented.

  18. Persistent Ice on Lake Superior

    NASA Image and Video Library

    2017-12-08

    Though North America is a full month into astronomical spring, the Great Lakes have been slow to give up on winter. As of April 22, 2014, the Great Lakes were 33.9 percent ice covered. The lake they call Superior dominated the pack. In the early afternoon on April 20, 2014, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this natural-color image of Lake Superior, which straddles the United States–Canada border. At the time Aqua passed over, the lake was 63.5 percent ice covered, according to the NOAA Great Lakes Environmental Research Lab (GLERL). Averaged across Lake Superior, ice was 22.6 centimeters (8.9 inches) thick; it was as much as twice that thickness in some locations. GLERL researcher George Leshkevich affirmed that ice cover this spring is significantly above normal. For comparison, Lake Superior had 3.6 percent ice cover on April 20, 2013; in 2012, ice was completely gone by April 12. In the last winter that ice cover grew so thick on Lake Superior (2009), it reached 93.7 percent on March 2 but was down to 6.7 percent by April 21. Average water temperatures on all of the Great Lakes have been rising over the past 30 to 40 years and ice cover has generally been shrinking. (Lake Superior ice was down about 79 percent since the 1970s.) But chilled by persistent polar air masses throughout the 2013-14 winter, ice cover reached 88.4 percent on February 13 and 92.2 percent on March 6, 2014, the second highest level in four decades of record-keeping. Air temperatures in the Great Lakes region were well below normal for March, and the cool pattern is being reinforced along the coasts because the water is absorbing less sunlight and warming less than in typical spring conditions. The graph below, based on data from Environment Canada, shows the 2014 conditions for all of the Great Lakes in mid-April compared to the past 33 years. Lake Superior ice cover got as high as 95.3 percent on March 19. By April 22, it was

  19. Influence of permafrost on lake terraces of Lake Heihai (NE Tibetan Plateau)

    NASA Astrophysics Data System (ADS)

    Lockot, Gregori; Hartmann, Kai; Wünnemann, Bernd

    2013-04-01

    The Tibetan Plateau (TP) is one of the key regions for climatic global change. Besides the poles the TP is the third highest storage of frozen water in glaciers. Here global warming is three times higher than in the rest of the world. Additionally the TP provides water for billions of people and influences the moisture availability from the Indian and East Asian monsoon systems. During the Holocene extent and intensity of the monsoonal systems changed. Hence, in the last decades, a lot of work was done to reconstruct timing and frequency of monsoonal moisture, to understand the past and give a better forecast for the future. Comparative workings often show very heterogeneous patterns of timing and frequency of the Holocene precipitation and temperature maximum, emphasizing the local importance of catchment dynamics. In this study we present first results of lake Heihai (36°N, 93°15'E, 4500m a.s.l.), situated at the north-eastern border of the TP. The lake is surrounded by a broad band of near-shore lake sediments, attesting a larger lake extent in the past. These sediments were uplifted by permafrost, reaching nowadays heights ca. +8 meters above present lake level. Due to the uplift one of the main inflows was blocked and the whole hydrology of the catchment changed. To quantify the uplift of permafrost Hot Spot Analysis were accomplished at a DEM of the near-shore area. As a result regions of high permafrost uplift and those which mirror the original height of lake ground were revealed. The most obvious uplift took place in the northern and western part of the lake, where the four uplift centers are located. In contrast the southern and eastern areas show a rather degraded pattern (probably by fluvial erosion, thermokarst, etc.). The ancient lake bottom, without permafrost uplift was estimated to be 4-6 meters above the modern lake level. For a better understanding of permafrost interaction inside the terrace bodies a 5m sediment profile was sampled and

  20. Discrimination among spawning aggregations of lake herring from Lake Superior using whole-body morphometric characters

    USGS Publications Warehouse

    Hoff, Michael H.

    2004-01-01

    The lake herring (Coregonus artedi) was one of the most commercially and ecologically valuable Lake Superior fishes, but declined in the second half of the 20th century as the result of overharvest of putatively discrete stocks. No tools were previously available that described lake herring stock structure and accurately classified lake herring to their spawning stocks. The accuracy of discriminating among spawning aggregations was evaluated using whole-body morphometrics based on a truss network. Lake herring were collected from 11 spawning aggregations in Lake Superior and two inland Wisconsin lakes to evaluate morphometrics as a stock discrimination tool. Discriminant function analysis correctly classified 53% of all fish from all spawning aggregations, and fish from all but one aggregation were classified at greater rates than were possible by chance. Discriminant analysis also correctly classified 66% of fish to nearest neighbor groups, which were groups that accounted for the possibility of mixing among the aggregations. Stepwise discriminant analysis showed that posterior body length and depth measurements were among the best discriminators of spawning aggregations. These findings support other evidence that discrete stocks of lake herring exist in Lake Superior, and fishery managers should consider all but one of the spawning aggregations as discrete stocks. Abundance, annual harvest, total annual mortality rate, and exploitation data should be collected from each stock, and surplus production of each stock should be estimated. Prudent management of stock surplus production and exploitation rates will aid in restoration of stocks and will prevent a repeat of the stock collapses that occurred in the middle of the 20th century, when the species was nearly extirpated from the lake.