WorldWideScience

Sample records for survey western lake

  1. Survey of fishing gears of Oyan Lake, South Western Nigeria ...

    African Journals Online (AJOL)

    The total number of active boats recorded for the entire lake was 43,241 with Station 2 having the highest number, 3,287 (about 76%) and the least in Station 3 (dam site area), which was 130 (3%). No motorized boat was observed on the lake throughout the study period. All the boats were manually operated by paddling.

  2. Western Alaska ESI: LAKES (Lake Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector polygons representing lakes and land masses used in the creation of the Environmental Sensitivity Index (ESI) for Western Alaska. The...

  3. Can pelagic forage fish and spawning cisco (Coregonus artedi) biomass in the western arm of Lake Superior be assessed with a single summer survey?

    Science.gov (United States)

    Yule, D.L.; Stockwell, J.D.; Schreiner, D.R.; Evrard, L.M.; Balge, M.; Hrabik, T.R.

    2009-01-01

    Management efforts to rehabilitate lake trout Salvelinus namaycush in Lake Superior have been successful and the recent increase in their numbers has led to interest in measuring biomass of pelagic prey fish species important to these predators. Lake Superior cisco Coregonus artedi currently support roe fisheries and determining the sustainability of these fisheries is an important management issue. We conducted acoustic and midwater trawl surveys of the western arm of Lake Superior during three periods: summer (July-August), October, and November 2006 to determine if a single survey can be timed to estimate biomass of both prey fish and spawning cisco. We evaluated our methods by comparing observed trawl catches of small (cisco increased substantially in November, while small bloater Coregonus hoyi biomass was lower. We compared our summer 2006 estimates of total fish biomass to the results of a summer survey in 1997 and obtained similar results. We conclude that the temporal window for obtaining biomass estimates of pelagic prey species in the western arm of Lake Superior is wide (July through October), but estimating spawning cisco abundance is best done with a November survey.

  4. Repeat surveys of spawning cisco (Coregonus artedi) in western Lake Superior: timing, distribution and composition of spawning stocks

    Science.gov (United States)

    Yule, Daniel L.; Schreiner, Donald R.; Addison, Peter A.; Seider, Michael J.; Evrard, Lori M.; Geving, Steven A.; Quinlan, Henry R.

    2012-01-01

    Acoustic (AC) and midwater trawl (MT) surveys of spawning cisco (Coregonus artedi) in Lake Superior have been combined with commercial yield to estimate exploitation. To time surveys properly, it is important to understand when adults typically arrive at spawning grounds and how numbers change as the spawning season progresses. We conducted repeat autumn surveys during nighttime hours at coastal sites where commercial roe fisheries occur. Spawner densities increased significantly from October to mid-November, but differences measured at sites sampled from mid- to late-November were comparatively small. Spawners occupied the upper 20–30 m of the water column during mid-November before utilizing a wider range of depths by late-November. We compared repeat AC densities to temporal trends of catch-per-unit-effort (CPUE) in suspended commercial gillnets and found good agreement within sites. Because different gillnet mesh sizes were used in each roe fishery. CPUE and AC density were poorly correlated among sites. We recommend that future surveys be conducted between mid- and late-November, and that MT gear be used to measure cisco densities in the uppermost 10 m of the water column where AC estimates may be conservative. Given the short temporal window for assessing spawner density, we believe both AC-MT and gillnet surveys will be needed to ensure that harvest of different stocks is kept at a sustainable level.

  5. Western Lake Erie Restoration Assessment Degree Flowlines

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This represents the flowline network in Western Lale Erie Restoration Assessment (WLERA). It is attributed with the number of disconnections between the reach and...

  6. Diatoms (Bacillariophyceae from the Valley of the Great Lakes in Western Mongolia

    Directory of Open Access Journals (Sweden)

    Mark B. Edlund

    2010-06-01

    Full Text Available T he Valley of the Great Lakes (VOGL in western Mongolia is dominated by two main (Uvs, Khyargas and many minor closed basin lake systems. In 2004 and 2005, we sampled diatom communities from the surfi cial sediment of 64 lakes in the western Mongolian provinces of Uvs, Khovd, Zavkhan, and Bayan-Ulgii. Lakes ranged in water chemistry from fresh to hypersaline, oligotrophic to hypertrophic, and from low elevation VOGL lakes to high elevation lakes in the Altai Mountains. Over 300 diatom species were identifi ed in the sediment samples including a diverse fl ora limited to saline lakes, many widespread taxa, many new reports for the Mongolian diatom fl ora, and several new and possibly endemic species. We also review recent diatom literature from Mongolia including fl oristic surveys, paleo-ecology, and water quality studies.

  7. Togiak National Wildlife Refuge lake surveys, 1984

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Preliminary review of the data reveals that all lakes surveyed can be classified as having low conductibility, ranging from the low 20's for the Goodnews Lakes to...

  8. Freshwater lake seabird surveys 2012

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Alaska Peninsula/Becharof NWR complex hosts Becharof Lake, the largest lake within a National Wildlife Refuge system. In addition to this distinction, Becharof...

  9. Spatial distribution of seepage at a flow-through lake: Lake Hampen, Western Denmark

    DEFF Research Database (Denmark)

    Kidmose, Jacob Baarstrøm; Engesgaard, Peter Knudegaard; Nilsson, Bertel

    2011-01-01

    recharge patiern of the lake and relating these to the geologic history of the lake. Recharge of the surrounding aquifer by lake water occurs off shore in a narrow zone, as measured from lake–groundwater gradients. A 33-m-deep d18O profi le at the recharge side shows a lake d18O plume at depths...... that corroborates the interpretation of lake water recharging off shore and moving down gradient. Inclusion of lake bed heterogeneity in the model improved the comparison of simulated and observed discharge to the lake. The apparent age of the discharging groundwater to the lake was determined by CFCs, resulting......The spatial distribution of seepage at a flow-through lake in western Denmark was investigated at multiple scales with integrated use of a seepage meter, lake–groundwater gradients, stable isotope fractionation (d18O), chlorofl uorocarbon (CFC) apparent ages, land-based and off -shore geophysical...

  10. Schistosomiasis transmission at high altitude crater lakes in Western Uganda

    Directory of Open Access Journals (Sweden)

    Philbert Clouds

    2008-08-01

    Full Text Available Abstract Background Contrary to previous reports which indicated no transmission of schistosomiasis at altitude >1,400 m above sea level in Uganda, in this study it has been established that schistosomiasis transmission can take place at an altitude range of 1487–1682 m above sea level in western Uganda. Methods An epidemiological survey of intestinal schistosomiasis was carried out in school children staying around 13 high altitude crater lakes in Western Uganda. Stool samples were collected and then processed with the Kato-Katz technique using 42 mg templates. Thereafter schistosome eggs were counted under a microscope and eggs per gram (epg of stool calculated. A semi-structured questionnaire was used to obtain demographic data and information on risk factors. Results 36.7% of the pupils studied used crater lakes as the main source of domestic water and the crater lakes studied were at altitude ranging from 1487–1682 m above sea level. 84.6% of the crater lakes studied were infective with over 50% of the users infected. The overall prevalence of Schistosoma mansoni infection was 27.8% (103/370 with stool egg load ranging from 24–6048 per gram of stool. 84.3%( 312 had light infections (400 egg/gm of stool. Prevalence was highest in the age group 12–14 years (49.5% and geometric mean intensity was highest in the age group 9–11 years (238 epg. The prevalence and geometric mean intensity of infection among girls was lower (26%; 290 epg compared to that of boys (29.6%; 463 epg (t = 4.383, p Conclusion and recommendations The altitudinal threshold for S. mansoni transmission in Uganda has changed and use of crater water at an altitude higher than 1,400 m above sea level poses a risk of acquiring S. mansoni infection in western Uganda. However, further research is required to establish whether the observed altitudinal threshold change is as a result of climate change or other factors. It is also necessary to establish the impact this could

  11. Chirp Seismic Survey Tracklines - Lake Mead 2001

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Lake Mead is a large interstate reservoir located in the Mojave Desert of southeastern Nevada and northwestern Arizona. It was impounded in 1935 by the construction...

  12. Boomer Seismic Survey Tracklines - Lake Mead 2001

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Lake Mead is a large interstate reservoir located in the Mojave Desert of southeastern Nevada and northwestern Arizona. It was impounded in 1935 by the construction...

  13. Chirp Seismic Survey Tracklines - Lake Mead 1999

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Lake Mead is a large interstate reservoir located in the Mojave Desert of southeastern Nevada and northwestern Arizona. It was impounded in 1935 by the construction...

  14. Chirp Seismic Survey Tracklines - Lake Mead 2000

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Lake Mead is a large interstate reservoir located in the Mojave Desert of southeastern Nevada and northwestern Arizona. It was impounded in 1935 by the construction...

  15. Pleistocene lake level changes in Western Mongolia

    Science.gov (United States)

    Borodavko, P. S.

    2009-04-01

    Global cooling in the Early Pleistocene caused extensive continental glaciation in the northern hemisphere including the arid areas of Central Asia. The reduction of temperatures (particularly summer temperatures) reduced evaporation and strengthened the importance of precipitation. The simultaneity of "lakes periods" (pluvials) and stages of glaciation is established experience confirmed by investigations in the west of North America and Russia. In the Mongolian Great Lakes Depression new evidence for similar conditions is found. The Great Lakes Depression is one of the largest in Central Asia, and is divided into 2 main Lakes basins: Hyargas Lake Basin and Uvs Lake Basin. The basin is 600-650 km in length with a width of 200-250 km in the north and 60-100 km in the south. Total catchment area is about 186600 km2. The elevation of the basin floor is from 1700 m a.s.l. to 760 m a.s.l., decreasing to the north and south-east. The depression extends south-north and is bounded by mountains: Tannu-Ola to the north, Hangai to the east; Gobi Altai to the south and Mongolian Altay to the west. The maximum elevation of the mountains is 4000 m a.s.l. There are some mountains with an elevation between 2000 and 3000 m a.s.l in the lake catchment. These mountains are not glaciated today. The geological record [1] suggests the Great Lakes Depression already existed in the Mesozoic, but assumed its modern form only during the Pliocene-Quaternary when tectonic movements caused the uplift of the surrounding mountains. A phase of tectonic stability occurred during the Late Quaternary. The depression is filled by Quaternary fluvial, aeolian and lacustrine deposits (e.g. sand, pebbles). The Neogene deposits are represented by coloured clay, marl, sand and sandstone [1]. Hyargas Lake is the end base level of erosion of the lake group consisting of the Hara-Us Nur, Dorgon, Hara Nur and Airag lakes. Hyargas is one of the largest lakes in Mongolia, with a water surface of 1,407 km2. The

  16. Western Ontario: Waterfowl breeding population survey: 1986

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for western Ontario during 1986. The primary purpose of the survey is to provide...

  17. Drivers of pluvial lake distributions in western North America

    Science.gov (United States)

    Ibarra, D. E.; Oster, J. L.; Winnick, M.; Caves, J. K.; Ritch, A. J.; Chamberlain, C. P.; Maher, K.

    2016-12-01

    The distribution of large inland lakes in western North America during the Plio-Pleistocene is intimately linked to the regional hydroclimate and moisture delivery dynamics. We investigate the climatological conditions driving terminal basin lakes in western North America during the mid-Pliocene warm period and the latest Pleistocene glacial maximum. Lacustrine deposits and geologic proxies suggest that lakes and wet conditions persisted during both warm and cold periods in the southwest, despite dramatically different global climate, ice sheet configuration and pCO2 levels. We use two complementary methods to quantify the hydroclimate drivers of terminal basin lake levels. First, a quantitative proxy-model comparison is conducted using compilations of geologic proxies and an ensemble of climate models. We utilize archived climate model simulations of the Last Glacial Maximum (21 ka, LGM) and mid-Pliocene (3.3 Ma) produced by the Paleoclimate Modelling Intercomparison Project (PMIP and PlioMIP). Our proxy network is made up of stable isotope records from caves, soils and paleosols, lake deposits and shorelines, glacier chronologies, and packrat middens. Second, we forward model the spatial distribution of lakes in the region using a Budyko framework to constrain the water balance for terminally draining watersheds, and make quantitative comparisons to mapped lacustrine shorelines and outcrops. Cumulatively these two approaches suggest that reduced evaporation and moderate increases in precipitation, relative to modern, drove moderate to large pluvial lakes during the LGM in the Great Basin. In contrast, larger precipitation increases appear to be the primary driver of lake levels during the mid-Pliocene in the southwest, with this spatial difference suggesting a role for El Niño teleconnections. These results demonstrate that during past periods of global change patterns of `dry-gets-drier, wet-gets-wetter' do not hold true for western North America.

  18. Western Coal/Great Lakes Alternative export-coal conference

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    This conference dealt with using the Great Lakes/St. Lawrence Seaway as an alternative to the East and Gulf Coasts for the exporting of coal to Europe and the potential for a piece of the European market for the subbituminous coals of Montana and Wyoming. The topics discussed included: government policies on coal exports; the coal reserves of Montana; cost of rail transport from Western mines to Lake Superior; the planning, design, and operation of the Superior Midwest Energy Terminal at Superior, Wisconsin; direct transfer of coal from self-unloading lakers to large ocean vessels; concept of total transportation from mines to users; disadvantage of a nine month season on the Great Lakes; costs of maritime transport of coal through the Great Lakes to Europe; facilities at the ice-free, deep water port at Sept Iles; the use of Western coals from an environmental and economic viewpoint; the properties of Western coal and factors affecting its use; the feasibility of a slurry pipeline from the Powder River Basin to Lake Superior; a systems analysis of the complete hydraulic transport of coal from the mine to users in Europe; the performance of the COJA mill-burner for the combustion of superfine coal; demand for steam coal in Western Europe; and the effect the New Source Performance Standards will have on the production and use of Western coal. A separate abstract was prepared for each of the 19 papers for the Energy Data Base (EDB); 17 will appear in Energy Research Abstracts (ERA) and 11 in Energy Abstracts for Policy Analysis (EAPA). (CKK)

  19. Fish communities of fixed sites in the Western Lake Michigan Drainages, Wisconsin and Michigan, 1993-95

    Science.gov (United States)

    Sullivan, D.J.

    1997-01-01

    Fish communities were surveyed at 20 wadable stream sites during 1993-95 as part of the U.S. Geological Survey's (USGS) National Water- Quality Assessment (NAWQA) Program's assessment of the Western Lake Michigan Drainages. Part of the NAWQA design is to incorporate ecological data into an overall environmental assessment. Collection of fish-community data was part of this ecological assessment.

  20. Overwintered Hatchlings of Emys orbicularis from Lake Sülüklü (Western Anatolia, Turkey

    Directory of Open Access Journals (Sweden)

    Dinçer Ayaz

    2011-07-01

    Full Text Available During our monitoring survey of amphibians and Emys orbicularis in Lake Sülüklü (Western Anatolia, Turkey, we observed four overwintered hatchlings of European pond turtle on May 4 and 10, 2010. The average straightline maximum carapace length of the neonates captured was 26.48 mm and their average weight was 4.18 g. This observation is the second record for the Turkish population of Emys orbicularis.

  1. A Bathymetric Survey of Lake Toba, Indonesia: Further Results

    Science.gov (United States)

    Chesner, C. A.; Halsor, S. P.; Dolan, M. T.

    2008-12-01

    Lake Toba, the largest caldera lake in the world, formed following a supervolcano eruption 74,000 years ago in northern Sumatra. Explosive eruption of ~2800 km3 of silicic magma from a batholith sized magma body produced a 100 x 30 x 2 km deep caldera. Approximately 2/3 of the caldera floor is now covered by Lake Toba, obscuring volcanic landforms and geologic features critical to understanding the history of the caldera. In September 2005, we initiated a bathymetric survey of Lake Toba using a GPS linked sonar device mounted to a small boat. Traveling at a speed of 3-10 km/h, and using a bottom depth sampling rate of 1 sounding/sec, sonar data was collected along almost 200 km of transect lines. This survey produced lake-bottom profiles with detailed bathymetric expression, indicating that it would be possible to generate a high resolution bathymetric map of Lake Toba with additional surveying. The second phase of our data collection was done in May 2008. Collectively, the survey now consists of about 90 separate transect lines over nearly 600 km of lake bottom. Results from both surveys allow several first order observations concerning caldera formation, resurgent doming, lava dome emplacement, and large scale erosional events as follows. Samosir Island is a partly submerged resurgent dome whose overall size (~60 x 20 km) and shape can now be accurately determined. The dome retains its asymmetrical shape below the water line with gentle westward slopes that merge into the caldera wall. Its steep east face rapidly descends to water depths of >400 m near the eastern caldera margin. The Uluan block appears to be a smaller, symmetrical equivalent of the Samosir dome. However, its extremely steep western face is more similar to the abrupt caldera collapse scar than the east face of Samosir. The deepest parts of the lake are found at the base of the ring fracture fault, approximately 0.5 km from the shoreline, with depths of 500 m recorded along the northeastern ring

  2. Western Lake Erie Restoration Assessment Composite Model

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Well-established conservation planning principles and techniques framed by geodesign were used to assess the restorability of areas that historically supported...

  3. Western Lake Erie Restoration Assessment Dikes

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is the output of a python script/ArcGIS model that identifes dikes as having a difference in elevation above a certain threshold. If the elevation...

  4. Application of the Lake Habitat Survey method on the tropical ...

    African Journals Online (AJOL)

    The Lake Habitat Survey (LHS) method was developed to assess the ecological integrity of the physical habitat around lake and reservoir ecosystems, as well as to determine the magnitude of human pressure on lake systems. The LHS method has not previously been applied to tropical lakes but could potentially be a ...

  5. 76 FR 10403 - Western Digital Technologies, Inc., Coporate Headquaters/Hard Drive Development Division, Lake...

    Science.gov (United States)

    2011-02-24

    ... Employment and Training Administration Western Digital Technologies, Inc., Coporate Headquaters/Hard Drive... for the workers and former workers of Western Digital Technologies, Inc., Corporate Headquarters/Hard Drive Development Division, Lake Forest, California (Western Digital Technologies). The Department's...

  6. Effectiveness of a refuge for lake trout in western Lake Superior I: Empirical analysis of past performance

    Science.gov (United States)

    Johnson, Melissa J.; Hansen, Michael J.; Seider, Michael J.

    2015-01-01

    The Gull Island Shoal Refuge was created in 1976 in response to overfishing of the Lake Trout Salvelinus namaycush population in the Apostle Islands region of western Lake Superior. Our objective was to evaluate effectiveness of the refuge by determining whether Lake Trout abundance, growth, maturity, and mortality differed inside and outside the refuge. We compared abundance of wild and stocked fish captured inside and outside the refuge during spring large-mesh gill-net and summer graded-mesh gill-net surveys. We compared growth and mortality during four periods corresponding to four generations of wild Lake Trout, including the last generation that hatched before the refuge was instituted (sampled in 1981–1984) and three generations that were protected by the refuge (sampled in 1985–1992, 1993–2000, and 2001–2010). Maturity of wild fish inside and outside the refuge was compared only for the latter period (2001–2010) because maturity was not assessed earlier. After the refuge was created, wild Lake Trout abundance increased and stocked Lake Trout abundance decreased. Wild adults and juveniles were more abundant inside than outside the refuge, and stocked adults were less abundant inside than outside the refuge. Growth of wild fish did not differ inside versus outside the refuge before 2001, but wild fish grew faster to a shorter asymptotic length inside than outside the refuge during 2001–2010. Wild fish matured at a similar length but an older age inside than outside the refuge during 2001–2010. Survival of wild fish did not differ inside versus outside the refuge before 1993, but mortality was lower inside than outside the refuge during later periods (1993–2000 and 2001–2010). We conclude that the Gull Island Shoal Refuge enhanced the population growth of wild Lake Trout in the Apostle Islands region and should be retained in the future to sustain conditions that favor population growth.

  7. Hydrogeological features conditioning trophic levels of quarry lakes in western Po plain (north-western Italy)

    Science.gov (United States)

    De Luca, Domenico Antonio; Castagna, Sara; Lasagna, Manuela

    2013-04-01

    Quarry lakes occur in plains areas due to the extraction of alluvial sand and gravel used for grout and concrete in the construction industry. Excavation depths can reach and intersect the groundwater surface, thus creating a lake. Because of the need to optimize efficiency, the number of active open pit mines has increased in recent years; consequently, the global number of pit lakes will increase in coming decades (Castendyk and Eary 2009; Klapper and Geller 2001; Castro and Moore 2000). Similar to natural lakes, pit lakes are subject to eutrophication process, both during and after quarrying activity; during mining activity, the eutrophic level is strongly controlled by the excavation method. In the Piedmont territory (north-western Italy) there are 70 active quarry lakes, corresponding to approximately 0.1% of the entire plain area. Quarry lakes, located primarily along the main rivers occur in alluvial deposits of the plain area and have average depths between 20 and 30 m (maximum of 60 m deep) and surface areas between 3 and 30 hectares (Castagna 2008). The present study describes the trophic status of 23 active quarry lakes in the Piedmont plain that were evaluated by applying classifications from scientific literature. Currently, the majority of the studied quarry lakes may be defined as mesotrophic or eutrophic according to the trophic state classifications. Based on historic data, lake trophic levels have increased over time, during active mining. At the end of mining activity, further deterioration of water quality was expected, especially for smaller lakes with minimal oxygen stratification and higher levels of nutrients and algal growth. In addition, the paper focuses on the pit lake water quality and pit dimension; From an environmental perspective the excavation of quarry lakes with an appreciable size will likely result in a better safeguard of water quality and enhanced possibilities for lake end use after the cessation of mining. Piedmont quarry

  8. Recently surveyed lakes in northern Manitoba and Saskatchewan, Canada: characteristics and critical loads of acidity

    Directory of Open Access Journals (Sweden)

    Isaac WONG

    2010-08-01

    Full Text Available Based on minimal information, lakes in the western Canadian provinces of Manitoba (MB and Saskatchewan (SK have long been considered unaffected by acid rain. However, emissions of acidifying pollutants from MB smelters and oil sand processing in Alberta (AB may pose a developing threat. Surveys of 347 lakes located on geologically sensitive terrain in northern MB and SK were conducted to assess their acidification sensitivity and status. The survey domain (~193,000 km2 contained 81,494 lakes ≥1 ha in area. Small lakes dominated the inventory in terms of numbers, and large lakes dominated in terms of area. Survey lakes were selected using a stratified-random sampling design in 10 sampling blocks within the overall survey domain. Few lakes had pH <6, and only three (all in SK were acidic, i.e., Gran Alkalinity (Alk <0 μeq L–1. A broad range in lake sensitivity was apparent, and very sensitive lakes (low specific conductance, base cations and Alk were present in all sampling blocks. Dissolved organic carbon (DOC was an important constituent of many lakes. Critical loads (CL of acidity calculated using the Steady-State Water Chemistry model (SSWC revealed extremely low 5th percentile values for every block (range 1.9 to 52.7 eq ha–1 y–1. Block CL exceedances calculated using estimated S and N deposition for 2002 ranged from 54.5 to 909 eq ha–1 y–1. The largest exceedances were for sampling blocks located near smelter sources or downwind of the oil sands. Lake chemistry revealed by our surveys was compared to others conducted both nearby and outside Canada.

  9. Internal loading of phosphorus in western Lake Erie

    Science.gov (United States)

    Matisoff, Gerald; Kaltenberg, Eliza M.; Steely, Rebecca L.; Hummel, Stephanie K.; Seo, Jinyu; Gibbons, Kenneth J.; Bridgeman, Thomas B.; Seo, Youngwoo; Behbahani, Mohsen; James, William F.; Johnson, Laura; Doan, Phuong; Dittrich, Maria; Evans, Mary Anne; Chaffin, Justin D.

    2016-01-01

    This study applied eight techniques to obtain estimates of the diffusive flux of phosphorus (P) from bottom sediments throughout the western basin of Lake Erie. The flux was quantified from both aerobic and anaerobic incubations of whole cores; by monitoring the water encapsulated in bottom chambers; from pore water concentration profiles measured with a phosphate microelectrode, a diffusive equilibrium in thin films (DET) hydrogel, and expressed pore waters; and from mass balance and biogeochemical diagenetic models. Fluxes under aerobic conditions at summertime temperatures averaged 1.35 mg P/m2/day and displayed spatial variability on scales as small as a centimeter. Using two different temperature correction factors, the flux was adjusted to mean annual temperature yielding average annual fluxes of 0.43–0.91 mg P/m2/day and a western basin-wide total of 378–808 Mg P/year as the diffusive flux from sediments. This is 3–7% of the 11,000 Mg P/year International Joint Commission (IJC) target load for phosphorus delivery to Lake Erie from external sources. Using these average aerobic fluxes, the sediment contributes 3.0–6.3 μg P/L as a background internal contribution that represents 20–42% of the IJC Target Concentration of 15 μg P/L for the western basin. The implication is that this internal diffusive recycling of P is unlikely to trigger cyanobacterial blooms by itself but is sufficiently large to cause blooms when combined with external loads. This background flux may be also responsible for delayed response of the lake to any decrease in the external loading.

  10. Bathymetric survey of Lake Calumet, Cook County, Illinois

    Science.gov (United States)

    Duncker, James J.; Johnson, Kevin K.; Sharpe, Jennifer B.

    2015-01-01

    The U.S. Geological Survey collected bathymetric data in Lake Calumet and a portion of the Calumet River in the vicinity of Lake Calumet to produce a bathymetric map. The bathymetric survey was made over 3 days (July 26, September 11, and November 7, 2012). Lake Calumet has become a focus area for Asian carp rapid-response efforts by state and federal agencies, and very little bathymetric data existed prior to this survey. This bathymetric survey provides data for a variety of scientific and engineering studies of the area; for example, hydraulic modeling of water and sediment transport from Lake Calumet to the Calumet River.

  11. Bathymetric survey and estimation of the water balance of Lake ...

    African Journals Online (AJOL)

    Quantification of the water balance components and bathymetric survey is very crucial for sustainable management of lake waters. This paper focuses on the bathymetry and the water balance of the crater Lake Ardibo, recently utilized for irrigation. The bathymetric map of the lake is established at a contour interval of 10 ...

  12. Geochemistry and Mineralogy of Western Australian Salt Lake Sediments: Implications for Meridiani Planum on Mars.

    Science.gov (United States)

    Ruecker, A; Schröder, C; Byrne, J; Weigold, P; Behrens, S; Kappler, A

    2016-07-01

    Hypersaline lakes are characteristic for Western Australia and display a rare combination of geochemical and mineralogical properties that make these lakes potential analogues for past conditions on Mars. In our study, we focused on the geochemistry and mineralogy of Lake Orr and Lake Whurr. While both lakes are poor in organic carbon (Lake Orr and from 5.4 to 6.3 in Lake Whurr sediments. Lake Whurr sediments were dominated by orange and red sediment zones in which the main Fe minerals were identified as hematite, goethite, and tentatively jarosite and pyrite. Lake Orr was dominated by brownish and blackish sediments where the main Fe minerals were goethite and another paramagnetic Fe(III)-phase that could not be identified. Furthermore, a likely secondary Fe(II)-phase was observed in Lake Orr sediments. The mineralogy of these two salt lakes in the sampling area is strongly influenced by events such as flooding, evaporation, and desiccation, processes that explain at least to some extent the observed differences between Lake Orr and Lake Whurr. The iron mineralogy of Lake Whurr sediments and the high salinity make this lake a suitable analogue for Meridiani Planum on Mars, and in particular the tentative identification of pyrite in Lake Whurr sediments has implications for the interpretation of the Fe mineralogy of Meridiani Planum sediments. Western Australia-Salt lakes-Jarosite-Hematite-Pyrite-Mars analogue. Astrobiology 16, 525-538.

  13. Chase Lake National Wildlife Refuge Pelican Survey, North Dakota

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — June 10, 2014 marks the first use of Unmanned Aircraft Systems (UAS) at Chase Lake Wildlife Refuge for pelican surveys. The U.S. Geological Survey teamed up with the...

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

    Science.gov (United States)

    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.

  15. Bathymetric and morphometric surveys of the Montebello Lakes, Chiapas

    Directory of Open Access Journals (Sweden)

    Javier Alcocer

    2016-03-01

    Full Text Available This study presents the first bathymetric surveys and descriptions of the morphometric parameters of the major lakes of the national park and Ramsar Convention site Lagunas de Montebello, Chiapas, Mexico and represents the first contribution on these limnologically unknown lakes. The morphology of lacustrine basins has an important influence on the physical, chemical and biological dynamics, and limnological research must consider the bathymetry and the related morphometric parameters of the lakes. Of the more than 50 lakes that make up this karst lake system (including dolines, uvalas and poljes, 18 representative lakes were selected along a NW-SE transect. The lakes have widely varying dimensions and include small and deep, small and shallow, large and deep, and large and shallow lakes. The shapes of the lakes vary from circular to elliptical, and the basin resembles an inverted truncated cone. The orientation of the main axis follows the structural orientations of the karst landscape (i.e., faults, fractures and folds. The maximum lengths range from 0.14 to 3.2 km, the surface areas range from 1.1 ha to 306.6 ha, and the lake volumes range from 0.00004 to 0.08852 km3. Six lakes are among the deepest lakes in Mexico and have an average maximum depth of more than 50 m; the deepest lake has a maximum depth of 198 m. These depths favor prolonged stratification, which increases the probability of accumulating pollutants.

  16. Probabilistic forecasting of harmful algal blooms in western Lake Erie

    Science.gov (United States)

    Obenour, D. R.; Gronewold, A.; Stow, C.; Bertani, I.; Steger, C. E.; Ruberg, S. A.; Scavia, D.

    2014-12-01

    Over the past decade, there has been a dramatic rise in the magnitude of harmful algal blooms (HABs) in western Lake Erie. These cyanobacteria blooms have drawn attention to phosphorus loading, a common driver of freshwater productivity. However, it is unclear how much of the year-to-year variability in bloom size is explained by anthropogenic phosphorus loading, and how much variability is related to other factors, including weather/climate drivers and measurement error. Here, we aim to advance the state-of-the-art in HAB forecasting by explicitly quantifying uncertainties in late-summer bloom observations, and propagating them through a Bayesian modeling framework that relates bloom size to phosphorus load. Because of the need to accurately represent predictive uncertainty, different statistical formulations are critically evaluated through cross validation. A model based on a novel implementation of a gamma error distribution is found to provide the most realistic uncertainty characterization, as well as high predictive skill. Our results also underscore the benefits of a hierarchical approach that allows us to assimilate data sets from multiple sources. Finally, our modeling analysis suggests that Lake Erie has become increasingly susceptible to large cyanobacteria blooms. We explore the nature of this change and assess potential biophysical explanations.

  17. Survey and assessment of post volcanic activities of a young caldera lake, Lake Cuicocha, Ecuador

    Directory of Open Access Journals (Sweden)

    G. Gunkel

    2009-05-01

    Full Text Available Cuicocha is a young volcano adjacent to the inactive Pleistocene Cotacachi volcano complex, located in the western cordilleras of the Ecuadorian Andes. A series of eruptions with intensive ash emission and collapse of the caldera occurred around 4500–3000 y BP. A crater 3.2 km in diameter and a maximum depth of 450 m was formed. Further eruptions of the volcano occurred 1300 y BP and formed four smaller domes within the caldera. Over the last few hundred years, a caldera lake has developed, with a maximum depth of 148 m. The lake water is characterized by sodium carbonate with elevated concentrations of manganese, calcium and chloride. Nowadays, an emission of gases, mainly CO2, and an input of warm spring water occur in Lake Cuicocha. The zone of high activity is in the western basin of the lake at a depth of 78 m, and continuous gas emissions with sediment resuspension were observed using sonar. In the hypolimnion of the lake, CO2 accumulation occurs up to 0.2% saturation, but the risk of a limnic eruption can be excluded at present. The lake possesses monomictic stratification behaviour, and during overturn an intensive gas exchange with the atmosphere occurs. Investigations concerning the sedimentation processes of the lake suggest only a thin sediment layer of up to 10–20 cm in the deeper lake basin; in the western bay, in the area of gas emissions, the lake bottom is partly depleted of sediment in the form of holes, and no lake colmation exists. Decreases in the lake water level of about 30 cm y−1 indicate a percolation of water into fractures and fissures of the volcano, triggered by a nearby earthquake in 1987.

  18. Herpetile survey report: USFWS – Benton Lake NWR

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A preliminary survey was conducted to investigate the species occurrence and relative abundance of herpetiles on Benton Lake NWR (BLNWR). A few species of concern...

  19. National Aquatic Resource Surveys (NARS) N/P Values for Lakes – National Lake Assessment

    Data.gov (United States)

    U.S. Environmental Protection Agency — The National Aquatic Resource Survey (NARS) findings for nutrients in streams and lakes highlight that nutrient pollution is widespread across the United States and...

  20. 75 FR 65517 - Western Digital Technologies, Inc., Corporate Headquarters/Hard Drive Development Division, Lake...

    Science.gov (United States)

    2010-10-25

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF LABOR Employment and Training Administration Western Digital Technologies, Inc., Corporate Headquarters/Hard Drive Development Division, Lake Forest, CA; Notice of Affirmative Determination Regarding Application for...

  1. Waterbirds of alkaline lakes in Western Uganda | Pomeroy | Journal ...

    African Journals Online (AJOL)

    Uganda's only alkaline lakes are found in the Queen Elizabeth Conservation Area and the adjoining Kyambura Wildlife Reserve. ... The lakes are important scenically, for ecotourism, and for the conservation of waterbirds and plants; whilst Lake Katwe's traditional production of salt is of considerable economic significance.

  2. Geophysical Surveys of Bear Lake, Utah-Idaho, September, 2002 - Bathymetry (5m contours)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Bear Lake is a tectonic lake that has existed for at least several hundred thousand years. The lake basin is a relatively simple half graben, a spoon-shaped...

  3. Geophysical Surveys of Bear Lake, Utah-Idaho, September 2002 - Grab Sample Data (GRABS)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Bear Lake is a tectonic lake that has existed for at least several hundred thousand years. The lake basin is a relatively simple half graben, a spoon-shaped...

  4. Geophysical Surveys of Bear Lake, Utah-Idaho, 2002 - JPG Images of Seismic Data

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Bear Lake is a tectonic lake that has existed for at least several hundred thousand years. The lake basin is a relatively simple half graben, a spoon-shaped...

  5. Geophysical Surveys of Bear Lake, Utah-Idaho, 2002 - JPEG Images of Seismic Data

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Bear Lake is a tectonic lake that has existed for at least several hundred thousand years. The lake basin is a relatively simple half graben, a spoon-shaped...

  6. 02031 - Geophysical Surveys of Bear Lake, Utah-Idaho, September 2002 - Shot Point Navigation (CHRPSHT)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Bear Lake is a tectonic lake that has existed for at least several hundred thousand years. The lake basin is a relatively simple half graben, a spoon-shaped...

  7. Geophysical Surveys of Bear Lake, Utah-Idaho, September 2002 - Bathymetric Grid (BATHYGRD.TIF)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Bear Lake is a tectonic lake that has existed for at least several hundred thousand years. The lake basin is a relatively simple half graben, a spoon-shaped...

  8. Geophysical Surveys of Bear Lake, Utah-Idaho, September 2002 - JPEG Images of Sound Velocity Profiles

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Bear Lake is a tectonic lake that has existed for at least several hundred thousand years. The lake basin is a relatively simple half graben, a spoon-shaped...

  9. 02031 - Geophysical Surveys of Bear Lake, Utah-Idaho, September 2002 - Chirp Seismic Tracklines (CHRPTRK)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Bear Lake is a tectonic lake that has existed for at least several hundred thousand years. The lake basin is a relatively simple half graben, a spoon-shaped...

  10. 02031 - Geophysical Surveys of Bear Lake, Utah-Idaho, September, 2002 - Bathymetry Tracklines (BATHY_TRK)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Bear Lake is a tectonic lake that has existed for at least several hundred thousand years. The lake basin is a relatively simple half graben, a spoon-shaped...

  11. Geophysical Surveys of Bear Lake, Utah-Idaho, September 2002 - JPEG Images of Grab Samples

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Bear Lake is a tectonic lake that has existed for at least several hundred thousand years. The lake basin is a relatively simple half graben, a spoon-shaped...

  12. 02031 - Geophysical Surveys of Bear Lake, Utah-Idaho, September 2002 - Sound Velocity Profiles (SVP)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Bear Lake is a tectonic lake that has existed for at least several hundred thousand years. The lake basin is a relatively simple half graben, a spoon-shaped...

  13. Mercury sedimentation in lakes in western Whatcom County, Washington, USA and its relation to local industrial and municipal atmospheric sources

    Science.gov (United States)

    Paulson, A.J.; Norton, D.

    2008-01-01

    Concentrations of mercury (Hg) were measured in six dated cores from four lakes in western Whatcom County, Washington, USA, that were at various bearings from a chlor-alkali plant, two municipal waste incinerators and a municipal sewage sludge incinerator. The importance of atmospheric emissions of Hg from these local municipal and industrial sources was evaluating by comparing the temporal trends in sedimentation of the lake cores with the emission history of each Hg species and by examining the geographical distribution of Hg sedimentation in relation to the region's primary wind pattern. Local municipal and industrial sources of atmospheric Hg were not responsible for the majority of the Hg in the upper layer of sediments of Whatcom County lakes because of (1) the significant enrichment of Hg in lake sediments prior to emissions of local industrial and municipal sources in 1964, (2) smaller increases in Hg concentrations occurred after 1964, (3) the similarity of maximum enrichments found in Whatcom County lakes to those in rural lakes around the world, (4) the inconsistency of the temporal trends in Hg sedimentation with the local emission history, and (5) the inconsistency of the geographic trends in Hg sedimentation with estimated deposition. Maximum enrichment ratios of Hg in lake sediments between 2 and 3 that are similar to rural areas in Alaska, Minnesota, and New England suggest that global sources of Hg were primarily responsible for increases of Hg in Whatcom County lakes beginning about 1900. ?? 2007 GovernmentEmployee: U.S. Government, Department of Interior, U.S. Geological Survey.

  14. Reconstructing ~2,200 years of mass movement and tsunami events in a deep fjord-type lake, western Norway

    Science.gov (United States)

    Waldmann, Nicolas; Vasskog, Kristian; Simpson, Guy; Hansen, Louise; Ariztegui, Daniel; Chapron, Emmanuel; Nesje, Atle

    2016-04-01

    Rock avalanches are one of the most devastating geohazards in Norway. A recent example can be given by the September 1936 rock fall that released ca. 1 million m3 of gneissic bedrock from the Ramnefjell Mountain, 800 m above Lake Lovatnet in inner Nordfjord, western Norway. The rock fall plunged into the lake causing a tsunami with a maximum run-up of 74 m and causing 74 casualties. This rock failure opened a deep-seated fracture that may serve as a sliding surface threatening for the generation of potential new series of failures. Lake Lovatnet was surveyed combining simultaneously 1 in3 airgun multi-channel and 3.5 kHz (pinger) single-channel systems. The seismic survey was complemented by piston cores. The general seismic stratigraphy of the lake was reconstructed using the 1 in3 airgun multi-channel survey. The seismic data shows an overall succession of glaciomarine sediments deposited during glacier retreat at the termination of the last ice age and a transition to marine and lacustrine sedimentation, as glacio-isostatic rebound turned the fjord into a land-locked lake. Furthermore, a record of ~2200 years of mass wasting events were identified and dated in the sedimentary record and the events were further mapped in the geophysical data. A specially tailored physically-based numerical simulation was carried out on the 1936 rock fall and related tsunami event in Lake Lovatnet. This model allowed us to reconstruct the effects of such an event on a small lacustrine basin. The outcome of the model has been further validated against historical, marine and terrestrial information. Results from this study further permit to extend the record of mass wasting events beyond historical times, providing a data set that can be applied to comparable basins at various temporal and geographical scales.

  15. Spatial distribution and temporal development of high-mountain lakes in western Austria

    Science.gov (United States)

    Merkl, Sarah; Emmer, Adam; Mergili, Martin

    2015-04-01

    Glacierized high-mountain environments are characterized by active morphodynamics, favouring the rapid appearance and disappearance of lakes. On the one hand, such lakes indicate high-mountain environmental changes such as the retreat of glaciers. On the other hand, they are sometimes susceptible to sudden drainage, leading to glacial lake outburst floods (GLOFs) putting the downstream population at risk. Whilst high-mountain lakes have been intensively studied in the Himalayas, the Pamir, the Andes or the Western Alps, this is not the case for the Eastern Alps. A particular research gap, which is attacked with the present work, concerns the western part of Austria. We consider a study area of approx. 6,140 km², covering the central Alps over most of the province of Tyrol and part of the province of Salzburg. All lakes ≥250 m² located higher than 2000 m asl are mapped from high-resolution Google Earth imagery and orthophotos. The lakes are organized into seven classes: (i) ice-dammed; near-glacial (ii) moraine-dammed and (iii) bedrock-dammed; (iv) moraine-dammed and (v) bedrock-dammed distant to the recent glaciers; (vi) landslide-dammed; (vii) anthropogenic. The temporal development of selected lakes is investigated in detail, using aerial photographs dating back to the 1950s. 1045 lakes are identified in the study area. Only eight lakes are ice-dammed (i). One third of all lakes is located in the immediate vicinity of recent glacier tongues, half of them impounded by moraine (ii), half of them by bedrock (iii). Two thirds of all lakes are impounded by features (either moraines or bedrock) shaped by LIA or Pleistocenic glaciers at some distance to the present glacier tongues (iv and v). Only one landslide-dammed lake (vi) is identified in the study area, whilst 21 lakes are of anthropogenic origin (vii). 72% of all lakes are found at 2250-2750 m asl whilst less than 2% are found above 3000 m asl. The ratio of rock-dammed lakes increases with increasing

  16. Surficial geology and distribution of post-impoundment sediment of the western part of Lake Mead based on a sidescan sonar and high-resolution seismic-reflection survey

    Science.gov (United States)

    Twichell, David C.; Cross, VeeAnn A.; Rudin, Mark J.; Parolski, Kenneth F.

    1999-01-01

    Sidescan sonar imagery and high-resolution seismic-reflection profiles were collected in Las Vegas Bay and Boulder Basin of Lake Mead to determine the surficial geology as well as the distribution and thickness of sediment that has accumulated in these areas of the lake since the completion of Hoover Dam in 1935 (Gould, 1951). Results indicate that the accumulation of post-impoundment sediment is restricted to the original Colorado River bed which runs down the axis of Boulder Basin from Boulder Canyon to Hoover Dam, and the old Las Vegas Creek bed that bisects Las Vegas Bay. The sediment cover along the original Colorado River bed is continuous and is typically greater than 10-m thick throughout much of its length with the thickness in some areas exceeding 35 meters. The flat-lying nature of the deposits suggests that they are the result of turbidity currents that flow the length of the lake. The sediment cover in Las Vegas Bay is much thinner (rarely exceeding 2 m in thickness) and more discontinuous. The source for these sediments presumably is Las Vegas Wash and a series of other ephemeral washes that empty into this part of the lake. The presence of sediments along the entire length of the Las Vegas Creek bed suggests that turbidity currents probably are active here as well, and that sediment has been transported from these streams at least 10 km down the axis of this valley to where it enters Boulder Basin. Alluvial deposits and rock outcrops are still exposed on large parts of the lake floor.

  17. Pluvial lakes in the Great Basin of the western United States: a view from the outcrop

    Science.gov (United States)

    Reheis, Marith C.; Adams, Kenneth D.; Oviatt, Charles G.; Bacon, Steven N.

    2014-01-01

    Paleo-lakes in the western United States provide geomorphic and hydrologic records of climate and drainage-basin change at multiple time scales extending back to the Miocene. Recent reviews and studies of paleo-lake records have focused on interpretations of proxies in lake sediment cores from the northern and central parts of the Great Basin. In this review, emphasis is placed on equally important studies of lake history during the past ∼30 years that were derived from outcrop exposures and geomorphology, in some cases combined with cores. Outcrop and core records have different strengths and weaknesses that must be recognized and exploited in the interpretation of paleohydrology and paleoclimate. Outcrops and landforms can yield direct evidence of lake level, facies changes that record details of lake-level fluctuations, and geologic events such as catastrophic floods, drainage-basin changes, and isostatic rebound. Cores can potentially yield continuous records when sampled in stable parts of lake basins and can provide proxies for changes in lake level, water temperature and chemistry, and ecological conditions in the surrounding landscape. However, proxies such as stable isotopes may be influenced by several competing factors the relative effects of which may be difficult to assess, and interpretations may be confounded by geologic events within the drainage basin that were unrecorded or not recognized in a core. The best evidence for documenting absolute lake-level changes lies within the shore, nearshore, and deltaic sediments that were deposited across piedmonts and at the mouths of streams as lake level rose and fell. We review the different shorezone environments and resulting deposits used in such reconstructions and discuss potential estimation errors. Lake-level studies based on deposits and landforms have provided paleohydrologic records ranging from general changes during the past million years to centennial-scale details of fluctuations during the

  18. Eutrophic lakes as CO2 sinks - A survey of 19 lakes in India

    Science.gov (United States)

    Singh, G.

    2015-12-01

    Inland waters emit a substantial amount of CO2 every year, most recent syntheses estimate (Raymond et al. 2013, IPCC 2013). However, eutrophic water bodies, which constitute the majority of inland waters, are underrepresented in these syntheses and may absorb rather than emit CO2 because of their high productivity (Balmer and Downing 2011, Pacheco et al. 2013). We did a survey of 19 urban and peri-urban lakes in India across a wide range of climates and with varying levels of eutrophication to get a snapshot of lake air-water CO2 exchange. A majority of the lakes (12 out of 19) were undersaturated with CO2 during daytime. Surface water pCO2 varied from 26 to 4600 ppm. Using estimates of gas transfer velocity from two different methods, we found the average daytime flux of CO2 in these lakes to vary from -3.11 mg C m-2d-1 to 36 mg C m-2 d-1. Weighted-averages of pCO2 and flux using lake area were 692 ppm and 2.33 mg C m-2 d-1, respectively. However, these values were dominated by one large coastal lake that was saturated with CO2. The other 18 lakes yielded averages pCO2 and flux of 282 ppm and -0.65 mg C m-2 d-1. Eutrophication is one the biggest contemporary threats to the global freshwater supply, and is particularly severe in developing countries. This study, despite its limited scope, provides strong support to the fact that eutrophic lakes may act as CO2 sinks rather than sources. Follow-up studies on the diurnal and seasonal pCO2 trends and the metabolic characteristics of these lakes will reveal the determinants of their carbon metabolism.

  19. A database of georeferenced nutrient chemistry data for mountain lakes of the Western United States

    Science.gov (United States)

    Williams, Jason; Labou, Stephanie G.

    2017-05-01

    Human activities have increased atmospheric nitrogen and phosphorus deposition rates relative to pre-industrial background. In the Western U.S., anthropogenic nutrient deposition has increased nutrient concentrations and stimulated algal growth in at least some remote mountain lakes. The Georeferenced Lake Nutrient Chemistry (GLNC) Database was constructed to create a spatially-extensive lake chemistry database needed to assess atmospheric nutrient deposition effects on Western U.S. mountain lakes. The database includes nitrogen and phosphorus water chemistry data spanning 1964-2015, with 148,336 chemistry results from 51,048 samples collected across 3,602 lakes in the Western U.S. Data were obtained from public databases, government agencies, scientific literature, and researchers, and were formatted into a consistent table structure. All data are georeferenced to a modified version of the National Hydrography Dataset Plus version 2. The database is transparent and reproducible; R code and input files used to format data are provided in an appendix. The database will likely be useful to those assessing spatial patterns of lake nutrient chemistry associated with atmospheric deposition or other environmental stressors.

  20. Lake Aquilla - Habitat Survey Hill County, Texas

    Science.gov (United States)

    2017-08-01

    the nest, which is typically situated about one meter from the ground (Grzybowski 1995). These shrublands are a product of climate in the arid ...Lake Aquilla, Texas. Plot LA22 was located near N 31.99525° W 97.1425° in a low, poorly drained area that is semi -permanently flooded, only... Climate Center website ERDC/EL TR-17-16 57 (http://www.wcc.nrcs.usda.gov/ climate /wetlands.html) or the Web- based, Water-Budget, Interactive

  1. Preliminary fish survey of Lac Tseny in north- western Madagascar

    African Journals Online (AJOL)

    ABSTRACT. We surveyed the fish fauna of Lac Tseny, in the Sofia Region of northwestern Madagascar, during October 2010 by observ- ing commercial catches and targeted netting of areas used by endemic species. We recorded seven native fish species at the lake, including three endemic cichlids, a herring and a catfish ...

  2. Planktonic ciliate community structure in shallow lakes of lowland Western Europe.

    Science.gov (United States)

    Van Wichelen, Jeroen; Johansson, Liselotte S; Vanormelingen, Pieter; Declerck, Steven A J; Lauridsen, Torben L; De Meester, Luc; Jeppesen, Erik; Vyverman, Wim

    2013-11-01

    Temperate shallow meso- to eutrophic lakes can exist in one of two alternative states with contrasting foodwebs, referred to as the clear-water and the turbid state. We describe the planktonic ciliate communities of such lakes based on a survey of 66 northwestern European lakes. Ciliates were enumerated and identified to species level according to the quantitative protargol staining technique. Ciliate biomass was on average twice as high in the turbid than in the clear-water lakes. The ciliate communities were dominated by oligotrichs and protostomatids, and no differences in functional composition or α-diversity could be detected between turbid and clear-water lakes, although β-diversity tended to be higher in the latter. At the species level, however, community structure strongly differed between turbid and clear-water lakes, and several indicator species could be identified for the different lake categories. Variation partitioning showed that nutrient status did not explain ciliate community structure independent of the alternative states, while lake area was identified as an additional structuring factor for the ciliate communities. These results stress the importance of the ecosystem structure in shaping ciliate communities in temperate shallow lakes and suggest that nutrient status has little direct effect on ciliate community structure in such lakes. Copyright © 2013 Elsevier GmbH. All rights reserved.

  3. Incidence of pathogenic bacteria in the Asejire Lake, western Nigeria

    African Journals Online (AJOL)

    This was implied as a result of the presence of the bacteria (Escherichia coli) in this freshwater lake; other bacteria isolated include Pseudomonas and Micrococcus species. This water body is therefore considered unsuitable for drinking. KEY WORDS: Feacal contamination, presumptive coliform count, coliform bacteria ...

  4. Expressions of climate perturbations in western Ugandan crater lake sediment records during the last 1000 yr

    Science.gov (United States)

    Mills, K.; Ryves, D. B.; Anderson, N. J.; Bryant, C. L.; Tyler, J. J.

    2013-09-01

    Equatorial East Africa has a complex, regional patchwork of climate regimes, with multiple interacting drivers. Recent studies have focussed on large lakes and reveal signals that are smoothed in both space and time, and, whilst useful at a continental scale, are of less relevance when understanding short-term, abrupt or immediate impacts of climate and environmental changes. Smaller-scale studies have highlighted spatial complexity and regional heterogeneity of tropical palaeoenvironments in terms of responses to climatic forcing (e.g. the Little Ice Age [LIA]) and questions remain over the spatial extent and synchroneity of climatic changes seen in East African records. Sediment cores from paired crater lakes in western Uganda were examined to assess ecosystem response to long-term climate and environmental change as well as testing responses to multiple drivers using redundancy analysis. These archives provide annual to sub-decadal records of environmental change. The records from the two lakes demonstrate an individualistic response to external (e.g. climatic) drivers, however, some of the broader patterns observed across East Africa suggest that the lakes are indeed sensitive to climatic perturbations such as a dry Mediaeval Climate Anomaly (MCA; 1000-1200 AD) and a relatively drier climate during the main phase of the LIA (1500-1800 AD); though lake levels in western Uganda do fluctuate. The relationship of Ugandan lakes to regional climate drivers breaks down c. 1800 AD, when major changes in the ecosystems appear to be a response to sediment and nutrient influxes as a result of increasing cultural impacts within the lake catchments. The data highlight the complexity of individual lake response to climate forcing, indicating shifting drivers through time. This research also highlights the importance of using multi-lake studies within a landscape to allow for rigorous testing of climate reconstructions, forcing and ecosystem response.

  5. Remote Sensing and Underwater Glider Observations of a Springtime Plume in Western Lake Superior

    Science.gov (United States)

    Plumes are commonly observed in satellite imagery of western Lake Superior following storm events, and represent a significant cross-shelf pathway for sediment and other constituents. However, their subsurface extent is poorly understood. This study reports results from plume ob...

  6. Cross shore transport by wind-driven turbidity plumes in western Lake Superior

    Science.gov (United States)

    Turbidity plumes frequently occur in the western arm of Lake Superior and may represent a significant cross shelf transport mechanism for sediment, nutrient and organisms. We characterize a plume that formed in late April 2016 using observations from a suite of in situ sensors an...

  7. Investigations into early rift development and geothermal resources in the Pyramid Lake fault zone, Western Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Eisses, A.; Kell, A.; Kent, G.; Driscoll, N. [UCSD; Karlin, R.; Baskin, R. [USGS; Louie, J. [UNR; Pullammanappallil, S. [Optim

    2016-08-01

    A. K. Eisses, A. M. Kell, G. Kent, N. W. Driscoll, R. E. Karlin, R. L. Baskin, J. N. Louie, S. Pullammanappallil, 2010, Investigations into early rift development and geothermal resources in the Pyramid Lake fault zone, Western Nevada: Abstract T33C-2278 presented at 2010 Fall Meeting, AGU, San Francisco, Calif., 13-17 Dec.

  8. Notes on the fishes of western New Guinea III. The fresh water shark of Jamoer lake

    NARCIS (Netherlands)

    Boeseman, M.

    1964-01-01

    INTRODUCTION In 1954, during a visit to Hollandia, western New Guinea, it was rumoured that sharks had been observed in the fresh water of Jamoer Lake, at a distance by effluent river of about 130 km from the Arafoera Sea. For further information on the locality, including a map of the area, I refer

  9. The Fossil Fauna of the Islands Region of Western Lake Erie.

    Science.gov (United States)

    Bowe, Lulu M., Comp.

    The islands of western Lake Erie are rock-bound isles that abound in rocky outcrops and quarries. The rocks of these islands are of two distinct types, Silurian dolomites and Devonian limestones. The dolomites, exposed in the Bass Islands and Sister Islands are virtually devoid of fossils. Conversely, the limestones of Johnson Island, Marblehead,…

  10. Fishing with bed nets on Lake Tanganyika: a randomized survey.

    Science.gov (United States)

    McLean, Kate A; Byanaku, Aisha; Kubikonse, Augustine; Tshowe, Vincent; Katensi, Said; Lehman, Amy G

    2014-10-07

    Malaria is among the most common causes of death along Lake Tanganyika, a problem which many aid organizations have attempted to combat through the distribution of free mosquito bed nets to high-risk communities. The Lake Tanganyika Floating Health Clinic (LTFHC), a health-based non-governmental organization (NGO), has observed residents of the Lake Tanganyika basin using bed nets to fish small fry near the shoreline, despite a series of laws that prohibit bed net use and other fine-gauge nets for fishing, implemented to protect the near-shore fish ecology. The LTFHC sought to quantify the sources of bed nets and whether they were being used for fishing. The LTFHC conducted a survey of seven lakeside villages in Lagosa Ward, Tanzania. The government has divided each village into two to six pre-existing geographic sub-villages depending on population size. Seven households per sub-village were chosen at random for survey administration. The survey consisted of 23 questions regarding mosquito bed net practices, including the use of bed nets for fishing, as well as questions pertaining to any perceived changes to the fish supply. A total of 196 surveys were administered over a four-week period with a 100% response rate. Over 87% of households surveyed have used a mosquito bed net for fishing at some point. The majority of respondents reported receiving their bed net for free (96.4%), observing "many" residents of their village using bed nets for fishing (97.4%), and noticing a subjective decrease in the fish supply over time (64.9%). The findings of this study raise concerns that the use of free malaria bed nets for fishing is widespread along Lake Tanganyika, and that this dynamic will have an adverse effect on fish ecology. Further studies are indicated to fully define the scope of bed net misuse and the effects of alternative vector control strategies in water-based communities.

  11. An Igneous Origin for Features of a Candidate Crater-Lake System in Western Memnonia, Mars

    Science.gov (United States)

    Leverington, D. W.; Maxwell, T. A.

    2004-01-01

    The association of channels, inner terraces, and delta-like features with Martian impact craters has previously been interpreted as evidence in favor of the past existence of crater lakes on Mars. However, examination of a candidate crater-lake system in western Memnonia suggests instead that its features may have formed through igneous processes involving the flow and ponding of lava. Accumulations of material in craters and other topographic lows throughout much of the study region have characteristics consistent with those of volcanic deposits, and terraces found along the inner flanks of some of these craters are interpreted as having formed through drainage or subsidence of volcanic materials. Channels previously identified as inlets and outlets of the crater-lake system are interpreted instead as volcanic rilles. These results challenge previous interpretations of terrace and channel features in the study region and suggest that candidate crater lakes located elsewhere should be reexamined.

  12. 76 FR 63991 - Midwest Rail d/b/a Toledo, Lake Erie and Western Railway-Lease and Operation Exemption-Toledo...

    Science.gov (United States)

    2011-10-14

    ... Surface Transportation Board Midwest Rail d/b/a Toledo, Lake Erie and Western Railway--Lease and Operation Exemption--Toledo, Lake Erie and Western Railway and Museum, Inc. Midwest Rail d/b/a Toledo, Lake Erie and Western Railway (Toledo), a noncarrier, has filed a verified notice of exemption under 49 CFR 1150.31 to...

  13. Expressions of climate perturbations in western Ugandan crater lake sediment records during the last 1000 years

    Science.gov (United States)

    Mills, K.; Ryves, D. B.; Anderson, N. J.; Bryant, C. L.; Tyler, J. J.

    2014-08-01

    Equatorial East Africa has a complex regional patchwork of climate regimes, sensitive to climate fluctuations over a variety of temporal and spatial scales during the late Holocene. Understanding how these changes are recorded in and interpreted from biological and geochemical proxies in lake sedimentary records remains a key challenge to answering fundamental questions regarding the nature, spatial extent and synchroneity of climatic changes seen in East African palaeo-records. Using a paired lake approach, where neighbouring lakes share the same geology, climate and landscape, it might be expected that the systems will respond similarly to external climate forcing. Sediment cores from two crater lakes in western Uganda spanning the last ~1000 years were examined to assess diatom community responses to late Holocene climate and environmental changes, and to test responses to multiple drivers using redundancy analysis (RDA). These archives provide annual to sub-decadal records of environmental change. Lakes Nyamogusingiri and Kyasanduka appear to operate as independent systems in their recording of a similar hydrological response signal via distinct diatom records. However, whilst their fossil diatom records demonstrate an individualistic, indirect response to external (e.g. climatic) drivers, the inferred lake levels show similar overall trends and reflect the broader patterns observed in Uganda and across East Africa. The lakes appear to be sensitive to large-scale climatic perturbations, with evidence of a dry Medieval Climate Anomaly (MCA; ca. AD 1000-1200). The diatom record from Lake Nyamogusingiri suggests a drying climate during the main phase of the Little Ice Age (LIA) (ca. AD 1600-1800), whereas the diatom response from the shallower Lake Kyasanduka is more complex (with groundwater likely playing a key role), and may be driven more by changes in silica and other nutrients, rather than by lake level. The sensitivity of these two Ugandan lakes to regional

  14. Finding the State Story in the National Lake Survey Data with an Excel Exploratory Tool

    Science.gov (United States)

    The National Lakes Assessment (NLA) surveyed over 1200 U.S. lakes in the summer of 2007, evaluating lake quality based on water quality, physical habitat, and indicators of biological and recreational condition. An upcoming national report will summarize survey results primarily ...

  15. Preliminary raptor surveys in western Mongolia

    Science.gov (United States)

    Ellis, D.H.; Ellis, Merlin H.; Tsengeg, Pu

    1995-01-01

    Raptors were observed on a 5200 km expedition from Ulaan Baatar through the Hangay Mountains to the Russian Altay Mountains with return through the Gobi Altay Mountains. The focus of the expedition was on nesting ecology of the Saker (Falco cherrug) and Altay falcons (F. altaicus) (25 eyries were located), but nests were also found for seven other species including more than 30 nests found of the upland buzzard (Buteo hemilasius). We conducted 21 day-long counts and 10 more formal raptor road counts. Raptors were concentrated in areas where perches were common and where food was most abundant. Western Mongolia remains a vast undeveloped land where camel trains and yak carts are normal. No developed highway network exists. Raptor work in the interior must be supported by four-wheel drive vehicles traveling cross country. Food and fuel for a research team are difficult to procure, but raptor populations are largely unexploited. Raptors frequently nest on the ground or on very low cliffs and tress, and often nest in close proximity of pairs of their own and other species. Several areas of special significance to raptors are discussed including the Taleen Ulaan (Red Steppe) areas of granite dells which we recommend for status as an international reserve.

  16. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: December 3, 2003

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  17. Bathymetric survey of Rock Run Rookery Lake, Will County, Illinois.

    Science.gov (United States)

    Duncker, James J.; Sharpe, Jennifer B.

    2017-01-01

    The bathymetric data set was collected in Rock Run on Dec. 10, 2015 by USGS ILWSC staff Clayton Bosch and Louis Pappas. The bathymetric data were collected with an RD Instruments 1200 kHz ADCP (S/N 8617) and Trimble Ag 162 GPS mounted on the M/V La Moine. A temporary reference point (TRP) was established on the north side of the footbridge over the connecting channel to the Des Plaines River. The mean water surface elevation (504.97 feet, WGS 84) during the survey was established from a temporary reference point whose elevation was later established by GPS survey. The measured depths were then converted to a lake bed elevation. The location and depth data were compiled into a bathymetry dataset (Rock Run Bathymetry Data.csv). The dataset was imported as a shapefile into ArcMap (ArcGIS software 10.3.1). A shape file of lake boundary elevation was developed based on imagery from September 16, 2015 (U.S. Department of Agriculture Farm Services Agency National Agriculture Imagery Program (NAIP)) (point data can be found in Rock Run Lake Boundary.csv). This shape file was merged with the elevation shape file to enforced the lake and island edges in the final bathymetry. This elevation shape file was then contoured using Geostatistical Analyst/Deterministic methods/Radial Basis Functions with Completely Regularized Spline (defaults were used except Sector type: 4 Sectors, Angle: 42, Major semiaxis: 800, Minor semiaxis: 500). The raster was then exported to a GeoTIFF file with a resulting raster cell size of 1 foot.

  18. Spatiotemporal variability and environmental factors of harmful algal blooms (HABs over western Lake Erie.

    Directory of Open Access Journals (Sweden)

    Di Tian

    Full Text Available Over the past decades, numerous studies have been carried out in understanding causes of Harmful Algal Blooms (HABs and their dynamics, yielding great knowledge in this field. Lake Erie, the fourth-largest lake of the five Great Lake, is among those highly vulnerable to the impacts of HABs and has received substantial attention from the public, water management sectors, and academic field. Building upon previous work, this study aims to characterize spatiotemporal variability of Chlorophyll a (Chl-a, which is an important indicator of HABs, and to explore relative importance of environmental factors associated with HABs in the west Lake Erie. Ten years of biweekly Chl-a information over western Lake Erie were derived from MERIS data at the pixel scale. Based on the MERIS-derived information high concentrations of Chl-a were observed in the south near shore area in spring and fall and in the west corner area of western Lake Erie in all three seasons except winter. Wavelet analysis suggested that the 0.5- and 1-year periods were dominant modes for the Chl-a series. The Multivariate Adaptive Regression Splines (MARS analysis was performed to explore factors associated with the dynamics of Chl-a. The results suggested that overall both phenological (e.g. wind and ecological (e.g. nutrient levels factors exhibited significant correlations with the remotely-sensed imagery based observations of Chl-a despite spatial and temporal variations. The important phenological and ecological factors include solar radiation and wind speed in spring, water temperature, solar radiation, and total Kjeldahl nitrogen concentration in summer, wind speed in fall, and water temperature and streamflow in winter. Both consistency and differences of findings of the study with others in the region may suggest strengths and limitations of the remotely sensed imagery-based analysis, offering valuable information for future work.

  19. Characterizing a cyanobacterial bloom in western Lake Erie using satellite imagery and meteorological data

    OpenAIRE

    Wynne, Timothy T.; Stumpf, Richard P.; Michelle C. Tomlinson; Dyble, Julianne

    2010-01-01

    The distribution and intensity of a bloom of the toxic cyanobacterium, Microcystis aeruginosa, in western Lake Erie was characterized using a combination of satellite ocean-color imagery, field data, and meteorological observations. The bloom was first identified by satellite on 14 August 2008 and persisted for more than 2 months. The distribution and intensity of the bloom was estimated using a satellite algorithm that is sensitive to near-surface concentrations of M. aeruginosa. Increases i...

  20. Turbidity in extreme western Lake Superior. [contamination of Duluth, Minnesota water intake

    Science.gov (United States)

    Sydor, M.

    1975-01-01

    Data were obtained from ERTS images for western Lake Superior for 1972-74. Data examination showed that for easterly winds the turbidity originating along the Wisconsin shore and the resuspension areas are transported northward then out along a N.E. path where it disperses, and often, for large storms, contaminates the Duluth water intake. Contaminants such as dredging fines anywhere along these paths would likewise find their way to the intake areas in concentrations comparable to the relative red clay concentration.

  1. Water-Oriented Recreational Demand and Projections: Calculations for Western Lake Superior.

    Science.gov (United States)

    1978-06-15

    feet in length). In each case , one or more computer tapes were supplied. These tapes were the most up-to-date available as of July 1977. Mailing Lists...true on Western Lake Superior. One of the most popular boating areas in the studyC area are the Apostle Islands. Boaters seeking the Apostle Islands...presents the case of Ashland and Washburn proposed harbors as, *. * examples. As previously stated, demand for berthing actually reflects the demand for

  2. High-resolution water column survey to identify active sublacustrine hydrothermal discharge zones within Lake Rotomahana, North Island, New Zealand

    Science.gov (United States)

    Walker, Sharon L.; de Ronde, Cornel E. J.; Fornari, Daniel; Tivey, Maurice A.; Stucker, Valerie K.

    2016-03-01

    Autonomous underwater vehicles were used to conduct a high-resolution water column survey of Lake Rotomahana using temperature, pH, turbidity, and oxidation-reduction potential (ORP) to identify active hydrothermal discharge zones within the lake. Five areas with active sublacustrine venting were identified: (1) the area of the historic Pink Terraces; (2) adjacent to the western shoreline subaerial "Steaming Cliffs," boiling springs and geyser; (3) along the northern shoreline to the east of the Pink Terrace site; (4) the newly discovered Patiti hydrothermal system along the south margin of the 1886 Tarawera eruption rift zone; and (5) a location in the east basin (northeast of Patiti Island). The Pink Terrace hydrothermal system was active prior to the 1886 eruption of Mount Tarawera, but venting along the western shoreline, in the east basin, and the Patiti hydrothermal system appear to have been initiated in the aftermath of the eruption, similar to Waimangu Valley to the southwest. Different combinations of turbidity, pH anomalies (both positive and negative), and ORP responses suggest vent fluid compositions vary over short distances within the lake. The seasonal period of stratification limits vertical transport of heat to the surface layer and the hypolimnion temperature of Lake Rotomahana consequently increases with an average warming rate of ~ 0.010 °C/day due to both convective hydrothermal discharge and conductive geothermal heating. A sudden temperature increase occurred during our 2011 survey and was likely the response to an earthquake swarm just 11 days prior.

  3. 02031 - Geophysical Surveys of Bear Lake, Utah-Idaho, September 2002 - Sidescan-sonar Tracklines (SSS_TRK)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Bear Lake is a tectonic lake that has existed for at least several hundred thousand years. The lake basin is a relatively simple half graben, a spoon-shaped...

  4. 02031 - Geophysical Surveys of Bear Lake, Utah-Idaho, September 2002 - Shot Point Navigation 500 shot interval (CHRP_500)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Bear Lake is a tectonic lake that has existed for at least several hundred thousand years. The lake basin is a relatively simple half graben, a spoon-shaped...

  5. 02031 : Geophysical Surveys of Bear Lake, Utah-Idaho, September 2002 - Seismic Navigation: Start of Line (CHRP_SOL)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Bear Lake is a tectonic lake that has existed for at least several hundred thousand years. The lake basin is a relatively simple half graben, a spoon-shaped...

  6. Sedimentary lipid biomarkers in the magnesium rich and highly alkaline Lake Salda (south-western Anatolia

    Directory of Open Access Journals (Sweden)

    Jérôme Kaiser

    2016-06-01

    Full Text Available Lake Salda located in south-western Anatolia is characterized by the presence of living stromatolites and by a low diversity of both phytoplankton and zooplankton due to high pH and magnesium concentration. The most abundant, free sedimentary lipids of the uppermost centimetres of the lake sediments were studied as potential environmental biomarkers, and proxies based on glycerol dialkyl glycerol tetraethers (GDGT were tested in this extreme environment. Dinosterol and tetrahymanol are potentially relevant biomarkers for the dinoflagellate Peridinium cinctum and ciliates, respectively. C20:1 and C25:2 highly branched isoprenoid (HBI alkenes, and n-C17 alkane and n-C17:1 alkene are considered as representing, respectively, diatoms and Cyanobacteria involved in the formation of the stromatolites. Isoprenoid GDGT-0 is assumed to be derived mainly from Euryarchaeota (methanogens, and crenarchaeol from Thaumarchaeota. Allochthonous organic material is represented by long-chain n-alkanes and n-alkanols derived from land plant leaf waxes, as well as branched GDGTs produced by soil bacteria. While pH and temperature proxies based on branched GDGTs are likely not applicable in Lake Salda, TEX86 (tetraether index of tetraethers consisting of 86 carbons, a proxy based on isoprenoid GDGTs, potentially allows estimating mean annual lake surface temperature. Interestingly, C23 and C25 1,2 diols, which have a yet unknown origin, were found for the first time in lake sediments. This study represents the first investigation of sedimentary lipid distribution in an alkaline and magnesium-rich lake in Anatolia, and provides a basis for future biomarker-based paleoenvironmental reconstruction of Lake Salda.

  7. Public perspectives of fire, fuels, and the Forest Service in the Great Lakes Region: a survey of citizen-agency communication and trust

    Science.gov (United States)

    Bruce A. Shindler; Eric Toman; Sarah M. McCaffrey

    2009-01-01

    Relative to the western United States, where fire and fuel management programs have received greater emphasis, few community-based studies have focused on the Great Lakes region. The present paper describes public opinion research from counties surrounding National Forests inWisconsin, Minnesota and Michigan. Survey data address citizen perspectives on (1) fuel...

  8. Delivered costs of Western coal shipped on the Great Lakes versus Eastern coal for Eastern Great Lakes hinterland utility plants. With appendices on relative cost impacts of coal scrubbing and on other Western coal transport systems

    Energy Technology Data Exchange (ETDEWEB)

    Bertram, K.M.

    1979-02-01

    This report analyzes the present and projected delivered cost competitiveness of Great Lakes shipped, low sulfur Western coal with low and high sulfur Eastern coal at Eastern Great Lakes hinterland utility plants. Its findings are based upon detailed data acquired from appropriate transportation firms and four eastern utility companies which use or have studied using the appropriate coal types. Two appendices provide: (1) a tentative, preliminary analysis of this competition with additional costs required by likely EPA scrubbing (sulfur removal) requirements, and (2) background information on other Western coal transport systems. Briefly, the findings of this report are that if Western coal is shipped via the Great Lakes to utility plants in the eastern Great Lakes hinterlands (i.e., inland from ports up to 200 miles): currently, based upon delivered costs only, it cannot compete with any type of Eastern coal; by 1989, with favorable interim Western versus Eastern cost escalation rate advantages on minemouth coal and transportation costs, Western coal delivered costs can begin competing with those of Eastern low sulfur, but not high sulfur coal; by 1999, with favorable relative cost escalation rate advantages, Western coal's delivered costs can become substantially less expensive than Eastern low sulfur coal's, and just begin to be competitive with Eastern high sulfur coal's; extremely high Eastern rail costs due to port area system characteristics are the main cost factor driving Western coal delivered costs to uneconomic levels.

  9. Acidophilic halophilic microorganisms in fluid inclusions in halite from Lake Magic, Western Australia.

    Science.gov (United States)

    Conner, Amber J; Benison, Kathleen C

    2013-09-01

    Lake Magic is one of the most extreme of hundreds of ephemeral acid-saline lakes in southern Western Australia. It has pH as low as 1.7, salinity as high as 32% total dissolved solids, temperatures ranging from 0°C to 50°C, and an unusually complex aqueous composition. Optical petrography, UV-vis petrography, and laser Raman spectrometry were used to detect microorganisms and organic compounds within primary fluid inclusions in modern bedded halite from Lake Magic. Rare prokaryotes appear as 1-3 μm, bright cocci that fluoresce green with UV-vis illumination. Dimpled, 5-7 μm yellow spherules that fluoresce blue with UV-vis illumination are interpreted as Dunaliella algae. Yellow-orange beta-carotene crystals, globules, and coatings are characterized by orange-red fluorescence and three distinct Raman peaks. Because acid saline lakes are good Mars analogues, the documentation of prokaryotes, eukaryotes, and organic compounds preserved in the halite here has implications for the search for life on Mars. Missions to Mars should incorporate such in situ optical and chemical examination of martian evaporites for possible microorganisms and/or organic compounds in fluid inclusions.

  10. The Origin of Basin of Great Lakes in Western Mongolia: Glaciated Super Valley, Not Super Flooding

    Science.gov (United States)

    Khukhuudei, Ulambadrakh; Otgonbayar, Orolzodmaa

    2015-04-01

    Research for morphology, its origin of the Basin of Great Lakes in Western Mongolia, is few and far between, particularly, any in recent years. The origin of the morphology of the basin presents a new study, combining previous study materials, their results and interpreting the digital photos. Also the main bases of theory is Pleistocene Last Glacial Maximum distribution. Many scholars have proven that global glaciation covered many areas of the Northern Hemisphere during the Pleistocene era. This global glaciation occurred in the northwest part of Mongolia to Mongolian Altay, Khangay and Khuvsgul mountain range. At the same time, the present appearance of basin that developed inheriting since the Mesozoic era, forms by global glaciation. The morphology of Basin of Great Lakes is super trough or glaciated super valley. At current day, "knock and lochan" topography (scoured region) and rock drumlins lie in the central part of the basin. Huge meltwater from this glaciation formed Shargasub-basin as a super kettle hole by erosion and overflowed water from it formed pluvial basins or big lakes in the Lake Valley.

  11. Recent climatological trends and potential influences on forest phenology around western Lake Superior, USA

    Science.gov (United States)

    Garcia, Matthew; Townsend, Philip A.

    2016-11-01

    We assess long-term climatological means, trends, and interannual variability around the western end of Lake Superior during 1984-2013 by using available weather station data. Our results focus on changes in basic and derived climate indicators from seasonal and annual temperature and precipitation, to the traditionally defined frost-free season, to a novel definition of the climatological growing season. We describe seasonal and year-to-year climate variability that influences forest phenology, using an alternative growing season metric that is based on the warm-season plateau in accumulated chilling days as an indicator of environmental triggers for vegetation growth and senescence. Our results indicate +0.56°C regional warming during our 30 year study period, with cooler springs (-1.26°C) and significant autumn warming (+1.54°C). The duration of the climatological growing season has increased +0.27 d/yr, extending primarily into autumn. Summer precipitation in our study area has declined by an average -0.34 cm/yr, potentially leading to moisture stress that impairs vegetation carbon uptake rates and can render the forest more vulnerable to disturbance. Many changes in temperature, precipitation, and climatological growing season are most prominent in locations where Lake Superior exerts a strong hydroclimatological influence, especially the Minnesota shoreline and in forest areas downwind (southeast) of the lake. Observed trends in lake temperature and ice phenology have also changed, coincident with a large-scale climatological regime shift around 1998. A number of factors are likely altering forest phenology and the role of the forest in the climate system of this ecologically important and highly varied forest-and-lake region.

  12. Ground-water quality in the western part of the Cambrian-Ordovician aquifer in the Western Lake Michigan Drainages, Wisconsin and Michigan

    Science.gov (United States)

    Saad, D.A.

    1996-01-01

    Ground-water samples were collected during the summer of 1995 from 29 wells in the western part of the Cambrian-Ordovician aquifer in the Western Lake Michigan Drainages study unit of the National-Water Quality Assessment Program. Analyses of ground-water samples from these wells were used to provide an indication of waterquality conditions in this heavily used part of the aquifer.

  13. The National Eutrophication Survey: lake characteristics and historical nutrient concentrations

    Science.gov (United States)

    Stachelek, Joseph; Ford, Chanse; Kincaid, Dustin; King, Katelyn; Miller, Heather; Nagelkirk, Ryan

    2018-01-01

    Historical ecological surveys serve as a baseline and provide context for contemporary research, yet many of these records are not preserved in a way that ensures their long-term usability. The National Eutrophication Survey (NES) database is currently only available as scans of the original reports (PDF files) with no embedded character information. This limits its searchability, machine readability, and the ability of current and future scientists to systematically evaluate its contents. The NES data were collected by the US Environmental Protection Agency between 1972 and 1975 as part of an effort to investigate eutrophication in freshwater lakes and reservoirs. Although several studies have manually transcribed small portions of the database in support of specific studies, there have been no systematic attempts to transcribe and preserve the database in its entirety. Here we use a combination of automated optical character recognition and manual quality assurance procedures to make these data available for analysis. The performance of the optical character recognition protocol was found to be linked to variation in the quality (clarity) of the original documents. For each of the four archival scanned reports, our quality assurance protocol found an error rate between 5.9 and 17 %. The goal of our approach was to strike a balance between efficiency and data quality by combining entry of data by hand with digital transcription technologies. The finished database contains information on the physical characteristics, hydrology, and water quality of about 800 lakes in the contiguous US (Stachelek et al.(2017), https://doi.org/10.5063/F1639MVD). Ultimately, this database could be combined with more recent studies to generate meta-analyses of water quality trends and spatial variation across the continental US.

  14. Würmian deglaciation of western Lake Geneva (Switzerland) based on seismic stratigraphy

    Science.gov (United States)

    Fiore, Julien; Girardclos, Stéphanie; Pugin, André; Gorin, Georges; Wildi, Walter

    2011-02-01

    Western Lake Geneva (le Petit-Lac) was filled during the Quaternary over a major erosion surface truncating the cemented, folded and thrusted Tertiary sediments of the foreland Alpine basin. The carving of the lake occurred during Quaternary glaciations with ice originating from the Rhone valley catchment basin flowing in two branches oriented SW and NE over the Swiss Plateau. Lake Geneva is situated on the South-Western branch of this paleo ice-cap. For the first time, a dense grid of high-resolution seismic profiles (airgun 5-inch 3, airgun 1-inch 3 and echosounder) has imaged the whole Quaternary sequence, providing a paleoenvironmental interpretation and a detailed reconstruction of the Rhone glacier retreat stages during glacial events that led to the formation of western Lake Geneva. The Quaternary sequence filling up the bedrock valley is exceptionally thick with up to 220 m of deposits and consists of glacial, glacio-lacustrine and lacustrine sediments. Fourteen seismic units have been defined (units U1-U14). Unit U1 represents the remnants of glacial deposits older than the last glacial cycle, preserved in the deepest part of the lake and in secondary bedrock valleys. Unit U2 represents gravel and sands deposited by meltwater circulation at the bottom of the glacial valley. Unit U3 is a thick, stratified unit marking the beginning of the deglaciation, when the Rhone glacier became thinner and buoyant and allowed the formation of a subglacial lake. Younger glacial units (units U4, U5, U7, U9, U11) are acoustically chaotic sediments deposited subglacially under the water table (undermelt tills), while the glacier was thinning. These glacial units are bounded by synform erosion surfaces corresponding to readvances of the glacier. The transition from a glacial to a glacio-lacustrine environment started with the appearance of a marginal esker-fan system (unit U6). Esker formation was followed by a small advance-retreat cycle leading to the deposition of unit U7

  15. Ice duration, winter stratification, and mixing behavior of subalpine lakes in western Maine

    Science.gov (United States)

    Daly, J.; Adams, S.; Abrams, R.; Engel, B.

    2011-12-01

    The timing and duration of both winter and summer periods of stratification periods is not well known for subalpine ponds in the northeastern United States. The remote nature of many of these lakes precludes detailed manual monitoring during the winter and the visual identification of major ice phenological events. These lakes are associated with ecological niches at or near their local elevation maximum that may be at risk due to climate change; historic ice-out records for larger regional lakes indicates a significant trend toward earlier ice-out in response to climate warming. We are using low-cost data loggers to develop high-resolution records characterizing water temperature variability at multiple depths in fifteen lakes 600 - 1000 m elevation. These lakes are located along a 175 km transect in western Maine; most are along the Appalachian Trail. The loggers are recording sub-hourly water temperature and light at the surface, two meters depth, and the bottom of each lake. The timing and duration of winter stratification and ice cover on these lakes are determined by distinctive temperature patterns recorded by the data loggers. The onset of winter stratification is marked by the expected temperature inversion and a slowly increasing hypolimnetic temperature; ice-on follows and is represented by the transition from daily heating cycles to a steady temperature over several days as the ice freezes in around the near-surface logger and energy loss is accomplished through a phase change rather than a drop in temperature. Once the ice is established, temperatures recorded by the near-surface logger vary daily, and are frequently below freezing in response to changing air temperature. Evaluation of winter 2009-2011 records shows that the duration of winter stratification exceeds ice duration at nearly every site. The timing of the onset of stratification is nearly uniform across the study area within each year of data, suggesting a nearly simultaneous response to

  16. Organic matter mineralization and trace element post-depositional redistribution in Western Siberia thermokarst lake sediments

    Directory of Open Access Journals (Sweden)

    S. Audry

    2011-11-01

    Full Text Available This study reports the very first results on high-resolution sampling of sediments and their porewaters from three thermokarst (thaw lakes representing different stages of ecosystem development located within the Nadym-Pur interfluve of the Western Siberia plain. Up to present time, the lake sediments of this and other permafrost-affected regions remain unexplored regarding their biogeochemical behavior. The aim of this study was to (i document the early diagenesic processes in order to assess their impact on the organic carbon stored in the underlying permafrost, and (ii characterize the post-depositional redistribution of trace elements and their impact on the water column. The estimated organic carbon (OC stock in thermokarst lake sediments of 14 ± 2 kg m−2 is low compared to that reported for peat soils from the same region and denotes intense organic matter (OM mineralization. Mineralization of OM in the thermokarst lake sediments proceeds under anoxic conditions in all the three lakes. In the course of the lake development, a shift in mineralization pathways from nitrate and sulfate to Fe- and Mn-oxyhydroxides as the main terminal electron acceptors in the early diagenetic reactions was suggested. This shift was likely promoted by the diagenetic consumption of nitrate and sulfate and their gradual depletion in the water column due to progressively decreasing frozen peat lixiviation occurring at the lake's borders. Trace elements were mobilized from host phases (OM and Fe- and Mn-oxyhydroxides and partly sequestered in the sediment in the form of authigenic Fe-sulfides. Arsenic and Sb cycling was also closely linked to that of OM and Fe- and Mn-oxyhydroxides. Shallow diagenetic enrichment of particulate Sb was observed in the less mature stages. As a result of authigenic sulfide precipitation, the sediments of the early stage of ecosystem development were a sink for water column Cu, Zn, Cd, Pb and Sb. In contrast, at all

  17. Cyanobacterial harmful algal blooms are a biological disturbance to Western Lake Erie bacterial communities.

    Science.gov (United States)

    Berry, Michelle A; Davis, Timothy W; Cory, Rose M; Duhaime, Melissa B; Johengen, Thomas H; Kling, George W; Marino, John A; Den Uyl, Paul A; Gossiaux, Duane; Dick, Gregory J; Denef, Vincent J

    2017-03-01

    Human activities are causing a global proliferation of cyanobacterial harmful algal blooms (CHABs), yet we have limited understanding of how these events affect freshwater bacterial communities. Using weekly data from western Lake Erie in 2014, we investigated how the cyanobacterial community varied over space and time, and whether the bloom affected non-cyanobacterial (nc-bacterial) diversity and composition. Cyanobacterial community composition fluctuated dynamically during the bloom, but was dominated by Microcystis and Synechococcus OTUs. The bloom's progression revealed potential impacts to nc-bacterial diversity. Nc-bacterial evenness displayed linear, unimodal, or no response to algal pigment levels, depending on the taxonomic group. In addition, the bloom coincided with a large shift in nc-bacterial community composition. These shifts could be partitioned into components predicted by pH, chlorophyll a, temperature, and water mass movements. Actinobacteria OTUs showed particularly strong correlations to bloom dynamics. AcI-C OTUs became more abundant, while acI-A and acI-B OTUs declined during the bloom, providing evidence of niche partitioning at the sub-clade level. Thus, our observations in western Lake Erie support a link between CHABs and disturbances to bacterial community diversity and composition. Additionally, the short recovery of many taxa after the bloom indicates that bacterial communities may exhibit resilience to CHABs. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  18. Temporal Variability and Environmental Drivers of Harmful Algal Blooms (HABs) in Western Lake Erie

    Science.gov (United States)

    Liang, S.; Tian, D.; Xie, G.; Tian, J.; Tseng, K. S.; Shum, C. K.; Lee, J.

    2014-12-01

    Understanding temporal variability and environmental drivers of harmful algal blooms (HABs) is important for guiding HABs impact mitigation plans in Lake Erie. The objective of this study is to characterize temporal variability and explore environmental driving factors of chlorophyll a (Chl-a) and phycocyanin (PC), which are determinants of HABs, in western Lake Erie. Ten years' (2002 to 2012) biweekly estimates of Chl-a and PC over western Lake Erie were retrieved from remote sensing-based measurements of water color with Medium Resolution Imaging Spectrometer ( MERIS). Nine environmental factors, including water quality and hydrometeorological variables, for the same period were also collected. While Chl-a and PC showed different predictabilities and differences in importance of environmental drivers at different locations and seasons using the Multivariate Adaptive Regression Splines (MARS) with the Variance Inflation Factor (VIF) method, hydrometeorological variables consistently showed great influences on Chl-a and PC in all four seasons. For Chl-a, the most significant environmental drivers are solar radiation and wind speed (spring); water temperature, solar radiation, and total Kjeldahl nitrogen concentration (summer); wind speed (fall); and water temperature and streamflow (winter). For PC, the most important environmental drivers are solar radiation and wind speed (spring); precipitation, water temperature, wind speed, and total Kjeldahl nitrogen concentration (summer); wind speed (fall); precipitation, water temperature, and streamflow ( winter). Wavelet analysis suggested that Chl-a and PC showed strong seasonal and inter-annual pattern - the 0.5- and 1-year periods are the dominant modes for both Chl-a and PC series. These findings offer insights into possible mechanisms underlying the dynamics of the HABs.

  19. Possible future lakes resulting from continued glacier shrinkage in the Aosta Valley Region (Western Alps, Italy)

    Science.gov (United States)

    Viani, Cristina; Machguth, Horst; Huggel, Christian; Godio, Alberto; Perotti, Luigi; Giardino, Marco

    2017-04-01

    Aosta Valley (NW-Alps, Italy) is the region with the largest glaciarized area of Italy (133.73 km2). Like the other alpine regions it has shown a significant glacier retreat starting from the end of the Little Ice Age (LIA, ca. 1850 AD), by losing about 60% of its glaciarized area. As a direct consequence of glacier shrinkage, within glacially-sculpted landscapes, glacier-bed overdeepenings become exposed, offering suitable conditions for glacier lakes formation. In the Aosta Valley region, about 200 glacier lakes have been recognized in different time periods within LIA maximum extent boundaries, mainly dammed by bedrock landforms. With respect to human activities, glacier lakes represent both opportunities (e.g. Miage lake for tourism) and risks (e.g. outburst flood of the Gran Croux lake above Cogne in August 2016) in such a densely populated and developed region. The objective of this contribution is to assess locations of possible future glacier lakes in the Aosta Valley by using the GlabTop2 model (Glacier Bed Topography model version 2). Understanding where future lakes will appear is of fundamental importance for the identification of potential hazards and the interpretation of conditioning factors and dynamics. We first assessed ice thickness and consequently glacier bed topography over large glaciated areas of the region, by using both glaciers outlines related to 1999 (provided by the GlaRiskAlp project) and the regional DEM of 1990 (provided by the Aosta Valley Region) as input data. We performed several runs by varying different input parameters (e,g.: pixel size and basal shear stress). Then we compared modelled results on selected test glaciers (Rutor and Grand Etrèt) with available GPR data. As a validation, we also carried out a GPR survey during summer 2016 on the central area of Indren Glacier (Monte Rosa massif) where GlabTop2 shows the presence of a possible subglacial overdeepening morphology. We found that ice thickness and consequently the

  20. Holocene climate in the western Great Lakes national parks and lakeshores: Implications for future climate change

    Science.gov (United States)

    Davis, Margaret; Douglas, Christine; Cole, K.L.; Winkler, Marge; Flaknes, Robyn

    2000-01-01

    We reconstruct Holocene climate history (last 10,000 years) for each of the U.S. National Park Service units in the western Great Lakes region in order to evaluate their sensitivity to global warming. Annual precipitation, annual temperature, and July and January temperatures were reconstructed by comparing fossil pollen in lake sediment with pollen in surface samples, assuming that ancient climates were similar to modern climate near analogous surface samples. In the early Holocene, most of the parks experienced colder winters, warmer summers, and lower precipitation than today. An exception is Voyageurs National Park in northern Minnesota where, by 8000 years ago, January temperatures were higher than today. The combination of high mean annual temperature and lower precipitation at Voyageurs resulted in a dry period between 8000 and 5000 years ago, similar to the Prairie Period in regions to the south and west. A mid-Holocene warm-dry period also occurred at other northern and central parks but was much less strongly developed. In southern parks there was no clear evidence of a mid-Holocene warm-dry period. These differences suggest that global model predictions of a warm, dry climate in the northern Great Plains under doubled atmospheric CO2 may be more applicable to Voyageurs than to the other parks. The contrast in reconstructed temperatures at Voyageurs and Isle Royale indicates that the ameliorating effect of the Great Lakes on temperatures has been in effect throughout the Holocene and presumably will continue in the future, thus reducing the potential for species loss caused by future temperature extremes. Increased numbers of mesic trees at all of the parks in the late Holocene reflect increasing annual precipitation. This trend toward more mesic conditions began 6000 years ago in the south and 4000 years ago in the north and increased sharply in recent millennia at parks located today in lake-effect snow belts. This suggests that lake-effect snowfall is

  1. Climate inferences between paleontological, geochemical, and geophysical proxies in Late Pleistocene lacustrine sediments from Summer Lake, Oregon, western Great Basin

    Science.gov (United States)

    Heaton, Eric; Thompson, Greg; Negrini, Rob; Wigand, Peter

    2016-04-01

    Paleontological, geochemical, and geophysical data from western Great Basin pluvial Summer Lake, Oregon have established a high resolution paleoclimate record during the late Pleistocene Mono Lake Excursion (~34.75 ka), Dansgaard-Oeschger interstadials 6-8, and the end of Heinrich Even 4 (~38 ka). Proxies of grain-size, magnetic susceptibility, carbon/nitrogen ratio, ostracode analysis and palynology from a depocenter core show new results with improved age control regarding high amplitude, high frequency changes in lake level, lake temperature, and regional precipitation and temperature which correspond directly with colder/warmer and respectively drier/wetter climates as documented with Northern Atlantic Greenland ice core data. Results from geophysical and geochemical analysis, and the presence of ostracode Cytherissa lacustris consistently demonstrate the correspondence of low lake conditions and colder water temperatures during Dansgaard-Oeschger stadials and the Mono Lake Excursion. The opposite holds true during interstadials. Smaller grain size, increases in carbon/nitrogen ratio and consistent absence of C. lacustris suggest periods of increased discharge into the lake, increased lake level, and warmer water temperatures. Warmer/wetter climate conditions are confirmed during interstadials 7 and 8 from pollen analysis. Existence of Atriplex, Rosaceae, Chrysothamnus and Ambrosia, and pollen ratios of Juniperus/Dip Pinus and (Rosaceae+Atriplex+Poaceae+Chrysothamnus+Ambrosia)/(Pinus+Picea+T. mertensiana+Sarcobatus) suggest warmer/wetter semi-arid woodland conditions during interstadials 7 and 8. This contrasts with absences in these pollens and pollen ratios indicating colder/drier continental montane woodland conditions during stadials and the Mono Lake Excursion. Increases in Juniper/Dip Pinus ratio suggest a warmer/wetter climate during interstadial 6 however additional proxies do not demonstrate comparative warmer/wetter climate, deeper lake level or

  2. Freshwater rotifers from Hordaland, western Norway, with a survey of freshwater rotifers previously found in Norway

    Directory of Open Access Journals (Sweden)

    Brit Godske Bjørklund

    2010-01-01

    Full Text Available   Bjørklund BG. 2009. Freshwater rotifers from Hordaland western Norway with a u survey of freshwater rotifers previously found in Norway. Fauna Norvegica29: 11-54. A total of 156 species (or subspecies o rotifers, mostly non-planktonic, have been identified from freshwater or slightly brackish-water localities in the county of Hordaland; 83 are new to Norway and 24 others are new to the county. One hundred of the species were collected from the two valleys of Eksingedalen and Teigdalen in spring and summer 1967. Samples were taken on the shallow shores of lake-like parts of the rivers, and in pools, tarns and small lakes. Forty more or less euryhaline fresh­water rotifers were also collected during studies of slightly brackish-water localities around Bergen in 1963-1969. A number of freshwater rotifers were collected at several localities in and around Bergen in 1968-1970, and on the western part of Hardangervidda. Of those so far identified ,23 are new to Norway and 8 more are new to the county. They are therefore included in the species list. A few additional ones are referred to in the taxonomical notes. All the species are listed with localities and habitat categories, or, in the case of the last-mentioned ones, just the district where they were collected. The paper includes notes, measurements and ,in most cases, figures regarding 44 little known, variable or taxonomically problematical species, especially in the genera Cephalodella and Trichocerca. Comments are given on the distribution , abundance and diversity of the species. The paper presents asurvey of previous investigations on rotifers in Norway, listing 200 previously recorded freshwater (a few euryhaline rotifers, giving other names, the authors who recorded the finds and, in most cases, the counties where the species were collected. 

  3. Subsurface Constraints on Late Cenozoic Basin Geometry in Northern Fish Lake Valley and Displacement Transfer Along the Northern Fish Lake Valley Fault Zone, Western Nevada

    Science.gov (United States)

    Mueller, N.; Kerstetter, S. R.; Katopody, D. T.; Oldow, J. S.

    2016-12-01

    The NW-striking, right-oblique Fish Lake Valley fault zone (FLVFZ) forms the northern segment of the longest active structure in the western Great Basin; the Death Valley - Furnace Creek - Fish Lake Valley fault system. Since the mid-Miocene, 50 km of right-lateral displacement is documented on the southern FLVFZ and much of that displacement was and is transferred east and north on active WNW left-lateral faults. Prior to the Pliocene, displacement was transferred east and north on a low-angle detachment. Displacement on the northern part of the FLVFZ continues and is transferred to a fanned array of splays striking (west to east) WNW, NNW, ENE and NNE. To determine the displacement budget on these structures, we conducted a gravity survey to determine subsurface basin morphology and its relation to active faults. Over 2450 stations were collected and combined with existing PACES and proprietary data for a total of 3388 stations. The data were terrain corrected and reduced to a 2.67 g/cm3 density to produce a residual complete Bouguer anomaly. The eastern part of northern Fish Lake Valley is underlain by several prominent gravity lows forming several sub-basins with maximum RCBA values ranging from -24 to -28 mGals. The RCBA was inverted for depth using Geosoft Oasis Montaj GM-SYS 3D modeling software. Density values for the inversion were constrained by lithologic and density logs from wells that penetrate the entire Cenozoic section into the Paleozoic basement. Best fitting gravity measurements taken at the wellheads yielded an effective density of 2.4 g/cm3 for the basin fill. Modeled basement depths range between 2.1 to 3 km. The sub-basins form an arc opening to the NW and are bounded by ENE and NNE faults in the south and NS to NNW in the north. At the northern end of the valley, the faults merge with ENE left-lateral strike slip faults of the Mina deflection, which carries displacement to NW dextral strike-slip faults of the central Walker Lane.

  4. Genome sequences of lower Great Lakes Microcystis sp. reveal strain-specific genes that are present and expressed in western Lake Erie blooms.

    Science.gov (United States)

    Meyer, Kevin Anthony; Davis, Timothy W; Watson, Susan B; Denef, Vincent J; Berry, Michelle A; Dick, Gregory J

    2017-01-01

    Blooms of the potentially toxic cyanobacterium Microcystis are increasing worldwide. In the Laurentian Great Lakes they pose major socioeconomic, ecological, and human health threats, particularly in western Lake Erie. However, the interpretation of "omics" data is constrained by the highly variable genome of Microcystis and the small number of reference genome sequences from strains isolated from the Great Lakes. To address this, we sequenced two Microcystis isolates from Lake Erie (Microcystis aeruginosa LE3 and M. wesenbergii LE013-01) and one from upstream Lake St. Clair (M. cf aeruginosa LSC13-02), and compared these data to the genomes of seventeen Microcystis spp. from across the globe as well as one metagenome and seven metatranscriptomes from a 2014 Lake Erie Microcystis bloom. For the publically available strains analyzed, the core genome is ~1900 genes, representing ~11% of total genes in the pan-genome and ~45% of each strain's genome. The flexible genome content was related to Microcystis subclades defined by phylogenetic analysis of both housekeeping genes and total core genes. To our knowledge this is the first evidence that the flexible genome is linked to the core genome of the Microcystis species complex. The majority of strain-specific genes were present and expressed in bloom communities in Lake Erie. Roughly 8% of these genes from the lower Great Lakes are involved in genome plasticity (rapid gain, loss, or rearrangement of genes) and resistance to foreign genetic elements (such as CRISPR-Cas systems). Intriguingly, strain-specific genes from Microcystis cultured from around the world were also present and expressed in the Lake Erie blooms, suggesting that the Microcystis pangenome is truly global. The presence and expression of flexible genes, including strain-specific genes, suggests that strain-level genomic diversity may be important in maintaining Microcystis abundance during bloom events.

  5. Genome sequences of lower Great Lakes Microcystis sp. reveal strain-specific genes that are present and expressed in western Lake Erie blooms.

    Directory of Open Access Journals (Sweden)

    Kevin Anthony Meyer

    Full Text Available Blooms of the potentially toxic cyanobacterium Microcystis are increasing worldwide. In the Laurentian Great Lakes they pose major socioeconomic, ecological, and human health threats, particularly in western Lake Erie. However, the interpretation of "omics" data is constrained by the highly variable genome of Microcystis and the small number of reference genome sequences from strains isolated from the Great Lakes. To address this, we sequenced two Microcystis isolates from Lake Erie (Microcystis aeruginosa LE3 and M. wesenbergii LE013-01 and one from upstream Lake St. Clair (M. cf aeruginosa LSC13-02, and compared these data to the genomes of seventeen Microcystis spp. from across the globe as well as one metagenome and seven metatranscriptomes from a 2014 Lake Erie Microcystis bloom. For the publically available strains analyzed, the core genome is ~1900 genes, representing ~11% of total genes in the pan-genome and ~45% of each strain's genome. The flexible genome content was related to Microcystis subclades defined by phylogenetic analysis of both housekeeping genes and total core genes. To our knowledge this is the first evidence that the flexible genome is linked to the core genome of the Microcystis species complex. The majority of strain-specific genes were present and expressed in bloom communities in Lake Erie. Roughly 8% of these genes from the lower Great Lakes are involved in genome plasticity (rapid gain, loss, or rearrangement of genes and resistance to foreign genetic elements (such as CRISPR-Cas systems. Intriguingly, strain-specific genes from Microcystis cultured from around the world were also present and expressed in the Lake Erie blooms, suggesting that the Microcystis pangenome is truly global. The presence and expression of flexible genes, including strain-specific genes, suggests that strain-level genomic diversity may be important in maintaining Microcystis abundance during bloom events.

  6. Norwegian lakes show widespread recovery from acidification; results from national surveys of lakewater chemistry 1986-1997

    Directory of Open Access Journals (Sweden)

    B. L. Skjelkvåle

    1998-01-01

    Full Text Available Surveys of 485 lakes in Norway conducted in 1986 and again in 1995 reveal widespread chemical recovery from acidification. Sulphate concentrations in lakes have decreased by 40% in acidified areas in southern Norway. This decrease has been compensated about 25% by decreases in concentrations of base cations and of 75% by increased Acid Neutralising Capacity (ANC. The increased ANC in turn reflects lower concentrations of acidic cations Aluminum (ALn+ and Hydrogen (H+. A sub-set of 78 of the 485 lakes sampled yearly between 1986 and 1997 shows that, at first most of the decrease in non-marine sulphate (SO4* was compensated by a decrease in base cations, such that ANC remained unchanged. Then as SO4* continued to decrease, the concentrations of non- marine calcium and magnesium ((Ca+Mg* levelled out. Consequently, ANC increased, and H+ and Aln+ started to decrease. In eastern Norway, this shift occurred in 1989–90, and came slightly later in southern and western Norway. Similar shifts in trends in about 1991–92 can also be seen in the non-acidified areas in central and northern Norway. This shift in trends is not as pronounced in western Norway, perhaps because of the confounding influence of sea-salt episodes on water chemistry. This is the first documented national-scale recovery from acidification due to reduced acid deposition. Future climate warming and potentially increased N-leaching can counteract the positive trends in recovery from acidification.

  7. Ground Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: November 14, 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The ground waterfowl surveys document the number of wintering, migratory waterfowl by species for each management unit on the Pungo Unit of Pocosin Lakes National...

  8. Surveys of brown bear predation on spawning sockeye salmon in three tributaries to Karluk Lake, Alaska.

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Surveys of live salmon and carcasses were made in three lateral tributaries to Karluk Lake. The objectives were to assess the impacts of bear predation on spawning...

  9. Chirp Seismic Shotpoint Navigation every 100 shots in Geographic Coordinates - Lake Mead Survey 2001

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Lake Mead is a large interstate reservoir located in the Mojave Desert of southeastern Nevada and northwestern Arizona. It was impounded in 1935 by the construction...

  10. Chirp Seismic Shotpoint Navigation every 100 shots in Geographic Coordinates - Lake Mead Survey 2000

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Lake Mead is a large interstate reservoir located in the Mojave Desert of southeastern Nevada and northwestern Arizona. It was impounded in 1935 by the construction...

  11. Chirp Seismic Shotpoint Navigation every 100 shots in Geographic Coordinates - Lake Mead Survey 1999

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Lake Mead is a large interstate reservoir located in the Mojave Desert of southeastern Nevada and northwestern Arizona. It was impounded in 1935 by the construction...

  12. A Dataset of Aerial Survey Counts of Harbor Seals in Iliamna Lake, Alaska: 1984-2013

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset provides counts of harbor seals from aerial surveys over Iliamna Lake, Alaska, USA. The data have been collated from three previously published sources...

  13. Lake Habitat and Fish Surveys on Interior Alaska National Wildlife Refuges, 1984–1986

    Data.gov (United States)

    Department of the Interior — A large-scale lake study on Interior Alaska National Wildlife Refuges (NWR) was undertaken from 1984–1986. Six NWRs were surveyed (Innoko, Kanuti, Koyukuk, Nowitna,...

  14. Aerial Survey Counts of Harbor Seals in Lake Iliamna, Alaska, 1984-2013 (NODC Accession 0123188)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset provides counts of harbor seals from aerial surveys over Lake Iliamna, Alaska, USA. The data have been collated from three previously published sources...

  15. Analysis of long-term forest bird monitoring data from national forests of the western Great Lakes Region

    Science.gov (United States)

    Gerald J. Niemi; Robert W. Howe; Brian R. Sturtevant; Linda R. Parker; Alexis R. Grinde; Nicholas P. Danz; Mark D. Nelson; Edmund J. Zlonis; Nicholas G. Walton; Erin E. Gnass Giese; Sue M. Lietz

    2016-01-01

    Breeding bird communities in forests of the western Great Lakes region are among the most diverse in North America, but the forest environment in this region has changed dramatically during the past 150 years. To address concerns about loss of biodiversity due to ongoing forest harvesting and to better inform forest planning, researchers have systematically monitored...

  16. Using lake sediment records to reconstruct bark beetle disturbances in western North America

    Directory of Open Access Journals (Sweden)

    Jesse Lee Morris

    2013-12-01

    Full Text Available The recent outbreak of native bark beetles in western North America is unprecedented in severity and scale, at least during the historical period. The aim of this work is to develop a proxy-based methodology to understand how bark beetle disturbances are recorded in lake sediments. Three hypotheses are tested to determine how the ecological impacts of severe spruce beetle (Dendroctonus rufipennis disturbances are recorded following mortality of Engelmann spruce (Picea engelmannii. Outbreaks are hypothesized to: (1 decrease the ratio of spruce to fir pollen; (2 increase soil erosion and mobilize terrestrial C; and (3 leach foliar N, enhancing algal productivity. To test these hypotheses, sediment cores from spruce beetle-affected basins were analyzed for pollen, insect remains, organic and minerogenic content, and isotopic and elemental concentrations. The dataset was tested statistically using generalized linear mixed models (GLMMs to determine if the response variables differed significantly between outbreak and non-outbreak periods. 

  17. Invasive vascular plant species of oxbow lakes in south-western Poland

    Directory of Open Access Journals (Sweden)

    Spałek Krzysztof

    2015-06-01

    Full Text Available Natural water reservoirs are very valuable floristic sites in south-western Poland. Among them, the most important for the preservation of biodiversity of flora are oxbow lakes. The long-term process of human pressure on habitats of this type caused disturbances of their biological balance. Changes in the water regime, industrial development and chemisation of agriculture, especially in the period of the last two hundred years, led to systematic disappearances of localities of many plant species connected with rare habitats and also to the appearance of numerous invasive plant species. They are: Azolla filiculoides, Echinocystis lobata, Erechtites hieraciifolia, Impatiens glandulifera, I. parviflora, Reynoutria japonica, Solidago canadensis, S. gigantea and S. graminifolia. Field works were conducted in years 2005-2012.

  18. Summary Totals and Use Days for Wintering, Migratory Waterfowl Surveys on Pocosin Lakes National Wildlife Refuge: 2003-2004

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  19. Southwestern Alaska archeological survey, Kagati Lake, Kisarilik-Kwethluk Rivers: A final research report to the National Geographic Society

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Discusses archeological survey of the east of Kagati Lake to Nenevok Lake, north to Trail Creek and Kwethluk River valleys, west along the Kwethluk and Kisaralik...

  20. Adirondack lakes survey: An interpretive analysis of fish communities and water chemistry, 1984--1987

    Energy Technology Data Exchange (ETDEWEB)

    Baker, J.P. (Baker (Joan P.), Raleigh, NC (USA)); Gherini, S.A.; Munson, R.K. (Tetra Tech, Inc., Pasadena, CA (USA)); Christensen, S.W. (Oak Ridge National Lab., TN (USA)); Driscoll, C.T. (Syracuse Univ., NY (USA)); Gallagher, J. (Adirondack Lakes Survey Corp., Ray Brook, NY (USA)); Newton, R.M. (Smith Coll., Northampton, MA (USA)); Reckhow, K.H. (Duke Univ., Durham, NC (USA)); Schofield, C.L. (Co

    1990-01-01

    The Adirondack Lakes Survey Corporation (ALSC) was formed as a cooperative effort of the New York State Department of Environmental Conservation and the Empire State Electric Energy Research Corporation to better characterize the chemical and biological status of Adirondack lakes. Between 1984 and 1987, the ALSC surveyed 1469 lakes within the Adirondack ecological zone. As a follow-up to the survey, the ALSC sponsored a series of interpretive analyses of the ALSC data base. The primary objectives of these analyses were as follows: Evaluate the influence of mineral acids (from acidic deposition) and nonmineral acids (natural organic acids) on lake pH levels; classify Adirondack lakes according to lake and watershed features expected to influence their responsiveness to changes in acidic deposition; evaluate the sensitivity of Adirondack lakes to changes in environmental conditions, such as changes in mineral acids or dissolved organic carbon concentrations; identify lake characteristics important in explaining the observed present-day status of fish communities in Adirondack lakes, in particular the relative importance of lake acidity; evaluate changes that have occurred over time in Adirondack fish communities and probable causes for these trends by using the available historical data on fish communities in the Adirondacks and the ALSC data base; and determine the degree to which the existing fish resource might be at risk from continued acidic deposition, or might recover if acidity levels were reduced. The basic approach examined relationships observed in the ALSC data base among watershed characteristics, lake chemistry, and fish status. Individual reports are processed separately for the data bases.

  1. Analysis of Coincident HICO and Airborne Hyperspectral Images Over Lake Erie Western Basin HABs

    Science.gov (United States)

    Cline, Michael T., Jr.

    Harmful algal blooms (HABs) produce waterborne toxins that pose a significant threat to people, livestock, and wildlife. Nearly 40 million people in both Canada and the U.S. depend on Great Lakes water. In the summer of 2014, in the Lake Erie Western Basin, an HAB of the cyanobacteria Microcystis was so severe that a do-not-drink advisory was in effect for the greater Toledo area, Ohio. This advisory applied to the water supply to over 400,000 people from a single water intake. Bloom intensity, composition, and spatial variability were investigated by comparing coincidental hyperspectral data from NASA's HICO, and NASA GRC's HSI airborne sensor, with on-lake ASD radiometer measurements and in situ water quality testing as ground reference data. Coincident data sets were obtained with HICO only on one day in 2014, however all other datasets coincide four times in 2015. Remote sensing data were atmospherically corrected using the empirical line method, utilizing dark reference spectra from a nearby asphalt parking lot measured from ASD and HSI radiometers. Cyanobacteria Index (CI) images were created from processed images using the Wynne (2010) algorithm, previously used for MODIS and MERIS imagery. This algorithm-generated CI images provide reliable results for both ground level (R2=0.921), airborne (R2=0.7981), and satellite imagery (R2=0.7794) for seven sampling points. The ability to robustly atmospherically correct and generate useful CI maps from airborne and satellite sensors can provide a time- and cost-effective method for HABs analysis. Timely processing of these high spatial and spectral resolution remote sensing data can aid in management of water intake resources. These results will help to improve methods leading to HABs mapping by testing different algal retrieval algorithms and atmospheric correction techniques using a three tiered hyperspectral sensor approach utilizing satellite, airborne, and ground level sensors, coupled with water quality

  2. Sympatric wolf and coyote populations of the western Great Lakes region are reproductively isolated.

    Science.gov (United States)

    Wheeldon, Tyler J; Patterson, Brent R; White, Bradley N

    2010-10-01

    Interpretation of the genetic composition and taxonomic history of wolves in the western Great Lakes region (WGLR) of the United States has long been debated and has become more important to their conservation given the recent changes in their status under the Endangered Species Act. Currently, the two competing hypotheses on WGLR wolves are that they resulted from hybridization between (i) grey wolves (Canis lupus) and western coyotes (C. latrans) or (ii) between grey wolves and eastern wolves (C. lycaon). We performed a genetic analysis of sympatric wolves and coyotes from the region to assess the degree of reproductive isolation between them and to clarify the taxonomic status of WGLR wolves. Based on data from maternal, paternal and bi-parental genetic markers, we demonstrate a clear genetic distinction between sympatric wolves and coyotes and conclude that they are reproductively isolated and that wolf-coyote hybridization in the WGLR is uncommon. The data reject the hypothesis that wolves in the WGLR derive from hybridization between grey wolves and western coyotes, and we conclude that the extant WGLR wolf population is derived from hybridization between grey wolves and eastern wolves. Grey-eastern wolf hybrids (C. lupus × lycaon) comprise a substantial population that extends across Michigan, Wisconsin, Minnesota and western Ontario. These findings have important implications for the conservation and management of wolves in North America, specifically concerning the overestimation of grey wolf numbers in the United States and the need to address policies for hybrids. © 2010 Blackwell Publishing Ltd.

  3. Influence of Survey Length and Radius Size on Grassland Bird Surveys by Point Counts at Williams Lake, British Columbia

    Science.gov (United States)

    Jean-Pierre L. Savard; Tracey D. Hooper

    1995-01-01

    We examine the effect of survey length and radius on the results of point count surveys for grassland birds at Williams Lake, British Columbia. Four- and 8-minute counts detected on average 68 percent and 85 percent of the number of birds detected during 12-minute counts. The most efficient sampling duration was 4 minutes, as long as travel time between points was...

  4. Geothermal activity at continental rift Citala, Western Mexico, where Lake Chapala is emplaced: past and present

    Science.gov (United States)

    Zárate-del Valle, P. F.

    2003-04-01

    Lake Chapala is a tectonic lake developed on a continental rift named Citala (CRC) which belongs to a tectonically active zone in Western Mexico: the so-called Jalisco continental triple junction. Fossil sinter deposit, thermal spring, hydrothermal (hy) petroleum manifestation and hy alteration halo characterized the Lake Chapala basin. On the SE shore, outcrops a carbonate deposit named ``La Calera" (LC) which consists of a carbonate fossil sinter that measures 2 km in E-W direction and 600 m in N-S direction and overlays andesitic rock. With a thickness of approximately 5 m and a roughly horizontal attitude, the LC is characterized by a two-fold structure: when massive, it is colored in yellow brownish and grey and elsewhere it shows a pseudo-brecciated structure and when banded, yellow and dark millimetre alternated bands can be seen. The LC is marked by vuggy porosity and silica (quartz and chalcedony) vein lets. Under microscope a pseudo-micritic texture is observed; vugs coated by iron oxides, are filled with calcite, and/or quartz, chalcedony and clay minerals. Six samples of LC were analysed (LODC-UParis VI) for their stable isotopes (δ18O and δ13C): From δ13C{PDB} values we have two sets of data: -8.03 to -8.69 ppm that means a no contribution of organic carbon (oc) and -0.35 to -0.75 ppm meaning an important contribution of oc; from δ18O{PDB} values: -8.5 to -10.27 ppm we deduced a deposit in meteoric water with a temperature deposition higher than the surface. The CRC is characterized also by the presence of hydrothermal petroleum (hp): Inside the Chapala and ˜2 km from SE shore (Los Arcos) there are some small spots made of hp which look like islands (bitumen. Thermal springs (ths) occur both inside and outside the lake Chapala: the water in out-shore ths is of carbonate type (69^oC; ˜ 240 mg L-1 [HCO_3]^-; with one exception: the ths at the San Juan Cosalá spa (N shore), which is of sulphate type (64-83^oC; ˜479 mg L-1 [SO_4]-2) and is

  5. Hydrothermal Petroleum in Active Continental Rift: Lake Chapala, Western Mexico, Initial Results.

    Science.gov (United States)

    Zarate-del Valle, P. F.; Simoneit, B. R.; Ramirez-Sanchez, H. U.

    2003-12-01

    Lake Chapala in western Mexico is located partially in the Citala Rift, which belongs to the well-known neotectonic Jalisco continental triple junction. The region is characterized by active volcanism (Ceboruco, Volcan de Fuego), tectonic (1995 earthquake, M=8, 40-50 mm to SW) and hydrothermal (San Juan Cosala & Villa Corona spas and La Calera sinter deposit) activities. Hydrothermal petroleum has been described in active continental rift (East African Rift) and marine spreading zones (Guaymas Basin, Gulf of California). In 1868 the Mexican local press reported that manifestations of bitumen were appearing in front of the Columba Cap on the mid south shore of Lake Chapala. This bitumen is linked to the lake bottom and when the water level decreases sufficiently it is possible to access these tar bodies as islands. Because of these manifestations the Mexican oil company (PEMEX) drilled an exploration well (2,348m) at Tizapan El Alto without success. Hydrothermal activity is evident in the tar island zone as three in-shore thermal springs (26.8 m depth, 48.5° C, pH 7.8 and oriented N-S). The preliminary analyses by GC-MS of the tar from these islands indicate hydrothermal petroleum derived from lake sedimentary organic matter, generated at low temperatures (150° -200° C). The tars contain no n-alkanes, no PAH or other aromatics, but a major UCM of branched and cyclic hydrocarbons and mature biomarkers derived from lacustrine biota. The biomarkers consist of mainly 17α (H),21β (H)-hopanes ranging from C27 to C34 (no C28), gammacerane, tricyclic terpanes (C20-C26), carotane and its cracking products, and drimanes (C14-C16). The biomarker composition indicates an organic matter source from bacteria and algae, typical of lacustrine ecosystems. 14C dating of samples from two tar islands yielded ages exceeding 40 kyrs, i.e., old carbon from hydrothermal/tectonic remobilization of bitumen from deeper horizons to the surface. The occurrence of hydrothermal petroleum in

  6. Stream habitat characteristics of fixed sites in the western Lake Michigan drainages, Wisconsin and Michigan, 1993-95

    Science.gov (United States)

    Fitzpatrick, F.A.; Giddings, E.M.

    1997-01-01

    Habitat characteristics of 11 fixed sites in the Western Lake Michigan Drainages were examined by the U.S. Geological Survey from 1993 through 1995 as part of the ecological assessment of the National Water-Quality Assessment Program. Evaluation of habitat consisted of more than 75 measurements at three spatial levels: drainage basin, stream segment between major tributaries (length from 1 to 14 kilometers), and stream reach (approximately 150 meters). The 11 fixed sites consisted of 8 "indicator" sites with drainage basins that differ in bedrock type, surficial deposits, and land use; and 3 "integrator" sites with drainage basins that contain a mixture of bedrock type, surficial deposits, and land use. Spatial and temporal variations in habitat characteristics are described and compared. Comparisons are limited to indicator sites except for comparisons amongbasin characteristics, which include all fixed sites. Two habitat classification schemes used in Wisconsin and Michigan were used to rank the quality of habitat in indicator streams. Reach-level data were collected at two additional reaches at three of the indicator sites to assess the representativeness of the reach for overall stream conditions.

  7. Understanding three decades of land use changes and a cloudburst in Phewa Lake Watershed, Western Nepal

    Science.gov (United States)

    Sudmeier-Rieux, Karen; Tonini, Marj; Vulliez, Cindy; Sanjaya, Devkota; Derron, Marc-Henri; Jaboyedoff, Michel

    2017-04-01

    This paper details an extreme rainfall event, or cloudburst (315 mm/ 24 hours) which occurred on July 29-30, 2015 in the Phewa Lake Watershed, Western Nepal, three months after the April 25, 2015 Gorkha Earthquake. The event triggered over 170 landslides and debris flows, caused 8 deaths and considerable damage to livelihoods. The fatal debris flow started from one of the numerous rural roads, which have proliferated exponentially over the past decades. In addition to mapping landslides due to this extreme rainfall event, our study sought to document and analyze underlying natural and human land use factors that may have impacted the occurrence of landsliding (Vulliez et al submitted). To do so, our study analyzed land cover/ land use changes for the period 1979-2016 based on an interpretation of aerial photos and satellite images, combined with ground truthing. We studied how land use / land cover changes have resulted in a shift of active erosion zones from overgrazing around streams and forests to an exponential number of small failures along unplanned earthen rural roads, or "bulldozer roads". With several hundred small failures documented along roadsides (Leibundgut et al., 2016) as compared to only 14 landslides prior to 2015 extreme rainfall event - and none triggered by the 2015 earthquake - roads are thus a major driver of active erosion zones and small failures in the watershed. More effective management of the current unsustainable mode of rural road construction is required to reduce further environmental and economic impacts on vulnerable populations in Nepal. Leibundgut, G., Sudmeier-Rieux, K. Devkota, S., Jaboyedoff, M., Derron, M-H., Penna, I. Nguyen, L. (2016). Rural earthen roads impact assessment in Phewa watershed, Western region, Nepal. Geoenvironmental Disasters (2016) 3:13. DOI 10.1186/s40677-016-0047-8 Vulliez, C, Tonini, M., Sudmeier-Rieux, K. Devkota, S., Derron, M-H, Jaboyedoff, M. (submitted) Land use changes, landslides and roads in the

  8. Structural Setting of the Emerson Pass Geothermal Anomaly, Pyramid Lake Paiute Reservation, Western Nevada

    Science.gov (United States)

    Anderson, R. B.; Faulds, J. E.

    2012-12-01

    The Pyramid Lake area is favorable for geothermal development due to the tectonic setting of the region. The Walker Lane belt, a dextral shear zone that accommodates ~20% relative motion between the Pacific and North American plates, terminates northwestward in northeast California. NW-directed dextral shear is transferred to WNW extension accommodated by N-to -NNE striking normal faults of the Basin and Range. As a consequence, enhanced dilation occurs on favorably oriented faults generating high geothermal potential in the northwestern Great Basin. The NW-striking right-lateral Pyramid Lake fault, a major structure of the northern Walker Lane, terminates at the southern end of Pyramid Lake and transfers strain to the NNE-striking down to the west Lake Range fault, resulting in high geothermal potential. Known geothermal systems in the area have not been developed due to cultural considerations of the Pyramid Lake Paiute Tribe. Therefore, exploration has been focused on discovering blind geothermal systems elsewhere on the reservation by identifying structurally favorable settings and indicators of past geothermal activity. One promising area is the northeast end of Pyramid Lake, where a broad left step between the west-dipping range-bounding faults of the Lake and Fox Ranges has led to the formation of a broad, faulted relay ramp. Furthermore, tufa mounds, mineralized veins, and altered Miocene rocks occur proximal to a thermal anomaly discovered by a 2-m shallow temperature survey at the north end of the step-over in Emerson Pass. Detailed geologic mapping has revealed a system of mainly NNE-striking down to the west normal faults. However, there are three notable exceptions to this generality, including 1) a prominent NW-striking apparent right-lateral fault, 2) a NW-striking down to the south fault which juxtaposes the base of the mid-Miocene Pyramid sequence against younger late Tertiary sedimentary rocks, and 3) a NNE-striking down to the east normal fault

  9. Herpetological surveys of south-western and south-eastern regions ...

    African Journals Online (AJOL)

    The herpetofauna of part of the south-western (Lagos, Ogun and Oyo States) and south-eastern (Cross River State) regions were investigated. Specimens were located opportunistically during visual surveys. Both regions fall in the tropical zone, and the south-western region surveyed, was mostly lowland, degraded forests ...

  10. A new bathymetric survey of the Suwałki Landscape Park lakes

    Directory of Open Access Journals (Sweden)

    Borowiak Dariusz

    2016-12-01

    Full Text Available The results of the latest bathymetric survey of 21 lakes in the Suwałki Landscape Park (SLP are presented here. Measurements of the underwater lake topography were carried out in the years 2012–2013 using the hydroacoustic method (sonar Lawrence 480M. In the case of four lakes (Błędne, Pogorzałek, Purwin, Wodziłki this was the first time a bathymetric survey had been performed. Field material was used to prepare bathymetric maps, which were then used for calculating the basic size and shape parameters of the lake basins. The results of the studies are shown against the nearly 90 year history of bathymetric surveying of the SLP lakes. In the light of the current measurements, the total area of the SLP lakes is over 634 hm2 and its limnic ratio is 10%. Lake water resources in the park were estimated at 143 037.1 dam3. This value corresponds to a retention index of 2257 mm. In addition, studies have shown that the previous morphometric data are not very accurate. The relative differences in the lake surface areas ranged from –14.1 to 9.1%, and in the case of volume – from –32.2 to 35.3%. The greatest differences in the volume, expressed in absolute values, were found in the largest SLP lakes: Hańcza (1716.1 dam3, Szurpiły (1282.0 dam3, Jaczno (816.4 dam3, Perty (427.1 dam3, Jegłówek (391.2 dam3 and Kojle (286.2 dam3. The smallest disparities were observed with respect to the data obtained by the IRS (Inland Fisheries Institute in Olsztyn. The IMGW (Institute of Meteorology and Water Management bathymetric measurements were affected by some significant errors, and morphometric parameters determined on their basis are only approximate.

  11. Metal ion complex formation in small lakes of the Western Siberian Arctic zone

    Science.gov (United States)

    Kremleva, Tatiana; Dinu, Marina

    2017-04-01

    be predominantly in free, ionic or bound form with inorganic ligands. This state means paradox consequence that the increase of dissolved Fe content will lead to toxicity rise of other elements having less affinity to organic material. For surface waters of Western Siberian Arctic zone this situation is quite common. The total concentration of iron and aluminum ions in most lakes of tundra and northern taiga zones is approximately equal to water complexing ability. From the other side humic substances participation in inactivation of other more toxic metals (Cu, Pb, Cd, Cr, Ni et al.) will be poor. Arctic part of Western Siberia undergoes significant anthropogenic load due to extensive oil and gas recovery in this zone. Surface waters of Western Siberia are characterized by high natural content of iron, aluminum and copper ions and anthropogenic load of heavy metals makes the situation more serious.

  12. Radiocarbon Dating and age Inversions in Lake Chapala Late Holocene Sediments, Western Mexico.

    Science.gov (United States)

    Zarate-Del Valle, P.; Israde-Alcantara, I.; Ramírez-Sánchez, H.; Gómez-Salazar, S.; Ríos-Donato, N.

    2006-12-01

    Neotectonic Lake Chapala, the major Mexican freshwater reservoir lies at the north and northeast of the Citala Rift and is linked to history of the active Plio-Quaternary Transmexican Volcanic Belt geological province. Eight radiocarbon 14C dates were obtained on shallow sediment samples from a gravity corer (T46) of 5 cm in diameter and 1.7 m long. The core was collected from the western sector of Lake Chapala (103° 15.43' W, 20° 14.45' N) at water depth of 3.7 m (june 2000). In general, shallow sediments (clays (38.5%), carbonates (2.99%) and TiO2 (1.05%). Radiocarbon ages were measured by accelerator mass spectrometry (AMS) and were obtained through the organic carbon fraction extracted from the bulk sediment samples sliced every 20 cm taken from the whole core. Stratigraphically ordered from highest to lowest, the eight ages reported are: 1) 2,000 ±40 yr on sediments at 30 cm deep; 2) 1,920 ±35 yr on sediments at 50 cm deep; 3) 1,900 ±35 yr on sediments at 70 cm deep; 4) 2,080 ±35 yr on sediments at 90 cm deep; 5) 2,090 ±50 yr on sediments at 110 cm deep; 6) 2,190 ±35 yr on sediments at 130 cm deep; 7) 2,050 ±35 yr on sediments at 150 cm deep and, 8) 1,500 ±35 yr on sediments at 170 cm deep. From the top until 70 cm and from 130 to bottom we observe two age inversions; the interval apparently with no age inversions is from 70cm to 130cm. As it is known the age inversions observed may be due to a) ancient carbon being incorporated into the sediment during deposition; b) unrecognized bioturbation, c) Postdepositional alteration and, d) variations in the apparent geological ages of the different chemical phases comprising the total sediment. Basically, the factors probably causing the age inversion at Lake Chapala are: 1) incorporation of ancient carbon during deposition of sediments because of presence the 14C dating of samples from the hydrothermal bitumen islands, 31 km East from T46, yielded ages exceeding 40 ka; 2) unrecognized bioturbation. Because

  13. Abundance and distribution of benthic macroinvertebrates in offshore soft sediments in Western Lake Huron, 2001-2007

    Science.gov (United States)

    French, J. R. P.; Schaeffer, J.S.; Roseman, E.F.; Kiley, C.S.; Fouilleroux, A.

    2009-01-01

    Invasive species have had major impacts on the Great Lakes. This is especially true of exotic dreissenid mussels which are associated with decreased abundance of native macroinvertebrates and changes in food availability for fish. Beginning in 2001, we added a benthic macroinvertebrate survey to the USGS-Great Lakes Science Center's annual fall prey fish assessment of Lake Huron to monitor abundance of macrobenthos. Mean abundance of Diporeia, the most abundant benthic taxon in Lake Huron reported by previous investigators, declined greatly between 2001 and 2007. Diporeia was virtually absent at 27-m sites by 2001, decreased and was lost completely from 46-m depths by 2006, but remained present at reduced densities at 73-m sites. Dreissenids in our samples were almost entirely quagga mussels Dreissena bugensis. Zebra mussels Dreissena polymorpha were virtually absent from our samples, suggesting that they were confined to nearshore areas shallower than we sampled. Loss of Diporeia at individual sites was associated with arrival of quagga mussels, even when mussel densities were low. Quagga mussel density peaked during 2002, then decreased thereafter. During the study quagga mussels became established at most 46-m sites, but remained rare at 73-m sites. Length frequency distributions suggest that initial widespread recruitment may have occurred during 2001-2002. Like other Great Lakes, Lake Huron quagga mussels were associated with decreased abundance of native taxa, but negative effects occurred even though dreissenid densities were much lower. Dreissenid effects may extend well into deep oligotrophic habitats of Lake Huron.

  14. Critical nitrogen deposition loads in high-elevation lakes of the western US inferred from paleolimnological records

    Science.gov (United States)

    Saros, J.E.; Clow, D.W.; Blett, T.; Wolfe, A.P.

    2011-01-01

    Critical loads of nitrogen (N) from atmospheric deposition were determined for alpine lake ecosystems in the western US using fossil diatom assemblages in lake sediment cores. Changes in diatom species over the last century were indicative of N enrichment in two areas, the eastern Sierra Nevada, starting between 1960 and 1965, and the Greater Yellowstone Ecosystem, starting in 1980. In contrast, no changes in diatom community structure were apparent in lakes of Glacier National Park. To determine critical N loads that elicited these community changes, we modeled wet nitrogen deposition rates for the period in which diatom shifts first occurred in each area using deposition data spanning from 1980 to 2007. We determined a critical load of 1.4 kg N ha-1 year-1 wet N deposition to elicit key nutrient enrichment effects on diatom communities in both the eastern Sierra Nevada and the Greater Yellowstone Ecosystem. ?? 2010 Springer Science+Business Media B.V.

  15. Bdelloid Rotifers from Lakes above 1700 m in Western Italian Alps, with Taxonomic Notes on Dissotrocha macrostyla

    Science.gov (United States)

    Fontaneto, Diego; Melone, Giulio

    2003-11-01

    Benthic and periphytic bdelloid communities from 16 alpine lakes from 1700 to 2850 m above sea level in Sesia Valley (Piedmont region, North-western Italy), sampled during summer 2001 and 2002, were analyzed. Seventeen species were identified from these species-poor communities, with 1 to 6 species each. Dissotrocha macrostyla and Philodina citrina were the most common species, present in 10 lakes while 9 species were collected from one lake only. New morphological details from S.E.M. pictures of Dissotrocha macrostyla revealed that Dissotrocha macrostyla tuberculata (Gosse, 1886) is only a seasonal morphotype. Its different appearance is due to the presence of locally distributed microscopic mucous bubbles (diameter 1.41 +/- 0.18 m) on the trunk surface, produced by the rotifer itself under stressful conditions.

  16. Out of the Tropics: The Pacific, Great Basin Lakes, and Late Pleistocene Water Cycle in the Western United States

    Science.gov (United States)

    Lyle, Mitchell; Heusser, Linda; Ravelo, Christina; Yamamoto, Masanobu; Barron, John; Diffenbaugh, Noah S.; Herbert, Timothy; Andreasen, Dyke

    2012-09-01

    The water cycle in the western United States changed dramatically over glacial cycles. In the past 20,000 years, higher precipitation caused desert lakes to form which have since dried out. Higher glacial precipitation has been hypothesized to result from a southward shift of Pacific winter storm tracks. We compared Pacific Ocean data to lake levels from the interior west and found that Great Basin lake high stands are older than coastal wet periods at the same latitude. Westerly storms were not the source of high precipitation. Instead, air masses from the tropical Pacific were transported northward, bringing more precipitation into the Great Basin when coastal California was still dry. The changing climate during the deglaciation altered precipitation source regions and strongly affected the regional water cycle.

  17. Out of the tropics: the Pacific, Great Basin lakes, and late Pleistocene water cycle in the western United States.

    Science.gov (United States)

    Lyle, Mitchell; Heusser, Linda; Ravelo, Christina; Yamamoto, Masanobu; Barron, John; Diffenbaugh, Noah S; Herbert, Timothy; Andreasen, Dyke

    2012-09-28

    The water cycle in the western United States changed dramatically over glacial cycles. In the past 20,000 years, higher precipitation caused desert lakes to form which have since dried out. Higher glacial precipitation has been hypothesized to result from a southward shift of Pacific winter storm tracks. We compared Pacific Ocean data to lake levels from the interior west and found that Great Basin lake high stands are older than coastal wet periods at the same latitude. Westerly storms were not the source of high precipitation. Instead, air masses from the tropical Pacific were transported northward, bringing more precipitation into the Great Basin when coastal California was still dry. The changing climate during the deglaciation altered precipitation source regions and strongly affected the regional water cycle.

  18. The Biogeography of Endorheic Soda Lakes in the Western United States

    Science.gov (United States)

    Stamps, B. W.; Petryshyn, V.; Johnson, H.; Berelson, W.; Nunn, H. S.; Stevenson, B. S.; Loyd, S. J.; Oremland, R. S.; Miller, L. G.; Rosen, M. R.; Corsetti, F. A.; Spear, J. R.

    2016-12-01

    Closed-basin (endorheic) soda lakes are of economic, social, and ecological importance. Shifts in global climate, which in turn affects local climate, significantly impact the distribution and diversity of microbial communities and lake ecologies. In California, the Mono Lake Basin (MLB) is especially fragile, as it has undergone a significant decline in lake level beginning in the early twentieth century due to both climatic effects and water diversion. The result is a lake with elevated salinity (60-90 g/L) and pH (9.8). The diversion of MLB water has created a unique lake environment dominated by a single macroeukaryote (Artemia monica) in which primary production is controlled at all depths by the microalgae Picocystis sp. In order to better understand the microbial diversity and functional potential of Mono Lake during an on-going drought and climatic upheaval, a combined geochemical, metagenomic, and metatranscriptomic study was undertaken. Members of The International GeoBiology course sampled the water column at multiple depths in the summer of 2016, during a large bloom of Picocystis. A mud spring from a volcanic island (Paoha) near the center of the lake was also sampled. The spring was recently submerged and interacts intermittently with Mono Lake, which may allow for mixing of microbial communities as lake levels fluctuate. Surface sediment samples were also taken from 7 m water depth. Finally, via SSU rRNA gene sequence analyses, the microbial communities of nearby soda lakes were compared in an attempt to place the Mono Lake community in the context of the overall regional biodiversity of endorheic soda lakes. Overall the microbial communities at Mono Lake were distinct both in the bacterial community composition and the abundance of Picocystis from those found at other sampled soda lakes or the surrounding rivers and springs. Our results reveal diverse microbial ecosystems at multiple lakes potentially at risk to continued climate change.

  19. Survey of Zooplanktons and Macro-Invertebrates of Gbedikere Lake ...

    African Journals Online (AJOL)

    Zooplankton and macro-invertebrates samples were collected weekly from three sampling stations at the Gbedikere Lake, Bassa Local Government Area, Kogi state, Nigeria from July to September 2008. Prior to sampling, Temperature of surface water, Secchi disc transparency, pH and dissolved oxygen concentration were ...

  20. A survey of medicinal plants around upper Songkhla lake, Thailand ...

    African Journals Online (AJOL)

    Conclusion: It was found that the natural sources of medicinal plants were damaged by many human activities. Therefore, this compilation of medicinal plants will be the data evidence for further conservation of the plants. Keywords: Medicinal plant, Ethnobotany, Traditional medicine, Upper Songkhla Lake, Thailand ...

  1. bathymetric survey and estimation of the water balance of lake ...

    African Journals Online (AJOL)

    Preferred Customer

    along these faults. Sometime during the. Quaternary Ardibo and the adjacent lake Hayq were connected by a channel through the Ankarka. River. Currently there is no ... Ctachment boundary. Rivers. Aqueduct. Eritrea. Sudan. Somalia. Kenya. Uganda study area. Ethiopia. Addis Ababa. Rift. Djibouti. Yemen. Saudi Arabia.

  2. Food of forage fishes in western Lake Erie, 1975-76

    Science.gov (United States)

    Muth, Kenneth M.; Busch, Wolf-Dieter N.

    1989-01-01

    In western Lake Erie in the summer and fall of 1975–1976, food eaten by seven forage fishes—emerald shiner (Notropis atherinoides), spottail shiner (Notropis hudsonius), trout-perch (Percopsis omiscomaycus), andyoung-of-the-year (YOY) of alewife (Alosa pseudoharengus), gizzard shad (Dorosoma cepedianum), white bass (Morone chrysops), and freshwater drum (Aplodi-notus grunniens)—was divided among six major taxa: Cladocera, Copepoda, Diptera, Ostracoda, Amphipoda, and Algae. In addition, fish were eaten by YOY white bass, and Rotifera were consumed by YOY gizzard shad. Interspecies diet overlap indices, calculated to compare the food of the different species and to evaluate diet similarities, were usually highest for YOY white bass and YOY freshwater drum when compared with the other species and usually lowest between emerald shiners and all other forage fishes. Understanding the feeding interactions among fishes that could influence production at the forage-food level of the food web could provide insight into how cascading trophic interactions influence the production of piscivorous predators.

  3. 1 meter resolution sidescan sonar image of data acquired during the U.S. Geological Survey Geophysical Surveys 02031 of Bear Lake, Utah-Idaho, September, 2002 (BEARLAKE.TIF, UTM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Bear Lake is a tectonic lake that has existed for at least several hundred thousand years. The lake basin is a relatively simple half graben, a spoon-shaped...

  4. 5 meter bathymetric contours derived from data collected during U.S. Geological Survey Geophysical Surveys of Bear Lake, Utah-Idaho, September, 2002 cruise 02031(02031_BATHY_5M)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Bear Lake is a tectonic lake that has existed for at least several hundred thousand years. The lake basin is a relatively simple half graben, a spoon-shaped...

  5. Magnetic, Electromagnetic, and Bathymetric Survey of the Lake of the Arbuckles, South-Central Oklahoma

    Science.gov (United States)

    Scheirer, D. S.; Smith, D. V.; Coffee, R.; Cason, J.

    2009-12-01

    In August 2009, we conducted a week-long geophysical and sonar survey of the Lake of the Arbuckles, within Chickasaw National Recreation Area in south-central Oklahoma. In this region, Pennsylvanian-aged orogenic deformation and sedimentation created the conditions that now govern the groundwater recharge, storage, and flow in the Arbuckle-Simpson aquifer, one of the most important bedrock aquifers in Oklahoma. The Lake of the Arbuckles reservoir, filled about 40 years ago, occupies an area where two major faults disrupt the geologic units that constitute the aquifer. The Reagan fault and the Mill Creek fault are hypothesized to intersect beneath the lake, based on available geologic exposures and inferences from gravity, magnetic, and helicopter electromagnetic (EM) observations in areas surrounding the lake. To understand the obscured geometry of these faults, we developed a pontoon-raft to carry a broad-band (15 kHz - 135 kHz) EM bird and a cesium-vapor magnetic sensor across the lake. We towed the raft 15 m behind a small boat to minimize EM and magnetic interference from the vessel, and we collected data on 200-m-spaced transects across much of the lake. The Reagan fault has a large electrical conductivity contrast and magnetic signature due to its juxtaposition at shallow depth of magnetic Proterozoic basement rocks with Paleozoic carbonate and clastic rocks. Initial results will show how the lake survey magnetic transects help to define the location of this fault beneath the lake. In addition, we collected dual-frequency sonar data to map the present-day bathymetry of the lake, and we collected vertical, water-column profiles of sound velocity, conductivity, temperature, pH, redox potential, and dissolved oxygen. The water-column profiles allow correction of the sonar travel-times to depth and estimation of the EM response of the lake water, which will be essential in later inversion modeling of the EM data. In addition, comparisons of the present

  6. Reinterpretation of the exposed record of the last two cycles of Lake Bonneville, Western United States

    Science.gov (United States)

    Scott, W.E.; McCoy, W.D.; Shroba, R.R.; Rubin, M.

    1983-01-01

    A substantially modified history of the last two cycles of Lake Bonneville is proposed. The Bonneville lake cycle began prior to 26,000 yr B.P.; the lake reached the Bonneville shoreline about 16,000 yr B.P. Poor dating control limits our knowledge of the timing of subsequent events. Lake level was maintained at the Bonneville shoreline until about 15,000 yr B.P., or somewhat later, when catastrophic downcutting of the outlet caused a rapid drop of 100 m. The Provo shoreline was formed as rates of isostatic uplift due to this unloading slowed. By 13,000 yr B.P., the lake had fallen below the Provo level and reached one close to that of Great Salt Lake by 11,000 yr B.P. Deposits of the Little Valley lake cycle are identified by their position below a marked unconformity and by amino acid ratios of their fossil gastropods. The maximum level of the Little Valley lake was well below the Bonneville shoreline. Based on degree of soil development and other evidence, the Little Valley lake cycle may be equivalent in age to marine oxygenisotope stage 6. The proposed lake history has climatic implications for the region. First, because the fluctuations of Lake Bonneville and Lake Lahontan during the last cycle of each were apparently out of phase, there may have been significant local differences in the timing and character of late Pleistocene climate changes in the Great Basin. Second, although the Bonneville and Little Valley lake cycles were broadly synchronous with maximum episodes of glaciation, environmental conditions necessary to generate large lakes did not exist during early Wisconsin time. ?? 1983.

  7. Lake Mohave Geophysical Survey 2002: GIS Data Release

    Science.gov (United States)

    Cross, VeeAnn A.; Foster, David S.; Twichell, David C.

    2005-01-01

    This CD-ROM contains sidescan-sonar imagery, sub-bottom reflection profiles, and an interpretive map derived from these data. These data were collected in Lake Mohave, a reservoir behind the Davis Dam and below the Hoover Dam on the Colorado River. These data are veiwable within an Environmental system Research Institute, Inc. (ESRI) Geographic Information system (GIS) ArcView 3.2 project file stored on this CD-ROM

  8. Site-specific estimates of water yield applied in regional acid sensitivity surveys across western Canada

    Directory of Open Access Journals (Sweden)

    Patrick D. SHAW

    2010-08-01

    Full Text Available Runoff or water yield is an important input to the Steady-State Water Chemistry (SSWC model for estimating critical loads of acidity. Herein, we present site-specific water yield estimates for a large number of lakes (779 across three provinces of western Canada (Manitoba, Saskatchewan, and British Columbia using an isotope mass balance (IMB approach. We explore the impact of applying site-specific hydrology as compared to use of regional runoff estimates derived from gridded datasets in assessing critical loads of acidity to these lakes. In general, the average water yield derived from IMB is similar to the long-term average runoff; however, IMB results suggest a much larger range in hydrological settings of the lakes, attributed to spatial heterogeneity in watershed characteristics and landcover. The comparison of critical loads estimates from the two methods suggests that use of average regional runoff data in the SSWC model may overestimate critical loads for the majority of lakes due to systematic skewness in the actual runoff distributions. Implications for use of site-specific hydrology in regional critical loads assessments across western Canada are discussed.

  9. Aerial survey of the proposed western addition to the Arctic National Wildlife Range

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — From April 23, 1974, until April 27, 1974, Averill Thayer, Manager of the Arctic National Wildlife Range, and I conducted an aerial survey of the proposed Western...

  10. Overlap in offshore habitat use by double-crested cormorants and boaters in western Lake Erie

    Science.gov (United States)

    Stapanian, Martin A.; Bur, Michael T.

    2002-01-01

    Double-crested cormorants (Phalacrocorax auritus) and boats of 2 length classes (≤ 8 m and > 8 m) were counted from a boat along 31 established strip transects in western Lake Erie from 24 April to 1 September 2000. Each transect included only one of the following habitats: (1) offshore of a breeding island or roosting/loafing area for cormorants (“refuge”), (2) reefs or shoals, (3) open water, or (4) offshore of an island shoreline that had evidence of development by humans. Foraging cormorants were recorded most often offshore of refuges and least often on open water. There was no difference between the numbers of foraging cormorants/km2 recorded offshore of developed shorelines and on reefs and shoals. More than half of all boats recorded were on transects that were within 1 km of developed shorelines. Among those transects > 1 km from developed shorelines, there were no differences among the habitats for the number of boats of either length class. The respective ranks of the 31 transect means of the numbers of cormorants/km2 and the numbers of boats/km2 in either length class were uncorrelated. The results suggest that (1) cormorants select foraging habitats based mainly on shoreline type, distance from shoreline, and depth, and (2) the amount of boat traffic is influenced by proximity to port and trip objectives, including sport angling and recreational boating. Although there is overlap in habitat use by cormorants and humans, this overlap is not complete. The perception of cormorants as a threat to fish populations may in part be due to this overlap.

  11. Effect of permafrost thawing on organic carbon and trace element colloidal speciation in the thermokarst lakes of western Siberia

    Directory of Open Access Journals (Sweden)

    O. S. Pokrovsky

    2011-03-01

    Full Text Available To examine the mechanisms of carbon mobilization and biodegradation during permafrost thawing and to establish a link between organic carbon (OC and other chemical and microbiological parameters in forming thermokarst (thaw lakes, we studied the biogeochemistry of OC and trace elements (TEs in a chronosequence of small lakes that are being formed due to permafrost thawing in the northern part of western Siberia. Twenty lakes and small ponds of various sizes and ages were sampled for dissolved and colloidal organic carbon, metals and culturable heterotrophic bacterial cell number. We observed a sequence of ecosystems from peat thawing and palsa degradation due to permafrost subsidence in small ponds to large, km-size lakes that are subject to drainage to, finally, the khasyrey (drained lake formation. There is a systematic evolution of both total dissolved and colloidal concentration of OC and TEs in the lake water along with the chronosequence of lake development that may be directly linked to the microbial mineralization of dissolved organic matter and the liberation of the inorganic components (Fe, Al, and TEs from the organo-mineral colloids.

    In this chronosequence of lake development, we observed an apparent decrease in the relative proportion of low molecular weight <1 kDa (1 kDa ~ 1 nm OC concentration along with a decrease in the concentration of total dissolved (<0.45 μm OC. This decrease was accompanied by an increase in the small size organic ligands (probably autochthonous exometabolites produced by the phytoplankton and a simultaneous decrease in the proportion of large-size organic (humic complexes of allochthonous (soil origin. This evolution may be due to the activity of heterotrophic bacterioplankton that use allochthonous organic matter and dissolved nutrients originating from peat lixiviation. Most insoluble TEs demonstrate a systematic decrease in concentration during filtration (5 μm, 0.45 μm exhibiting a similar

  12. A dynamic hydrological Monte Carlo simulation model to inform decision-making at Lake Toolibin, Western Australia.

    Science.gov (United States)

    Jones, Stuart; Lacey, Peter; Walshe, Terry

    2009-04-01

    Lake Toolibin, an ephemeral lake in the agricultural zone of Western Australia, is under threat from secondary salinity due to land clearance throughout the catchment. The lake is extensively covered with native vegetation and is a Ramsar listed wetland, being one of the few remaining significant migratory bird habitats in the region. Currently, inflow with salinity greater than 1000 mg/L TDS is diverted from the lake in an effort to protect sensitive lakebed vegetation. However, this conservative threshold compromises the frequency and extent of lake inundation, which is essential for bird breeding. It is speculated that relaxing the threshold to 5000 mg/L may pose negligible additional risk to the condition of lakebed vegetation. To characterise the magnitude of improvement in the provision of bird breeding habitat that might be generated by relaxing the threshold, a dynamic water and salt balance model of the lake was developed and implemented using Monte Carlo simulation. Results from best estimate model inputs indicate that relaxation of the threshold increases the likelihood of satisfying habitat requirements by a factor of 9.7. A second-order Monte Carlo analysis incorporating incertitude generated plausible bounds of [2.6, 37.5] around the best estimate for the relative likelihood of satisfying habitat requirements. Parameter-specific sensitivity analyses suggest the availability of habitat is most sensitive to pan evaporation, lower than expected inflow volume, and higher than expected inflow salt concentration. The characterisation of uncertainty associated with environmental variation and incertitude allows managers to make informed risk-weighted decisions.

  13. A survey of aquatic insects at Kware lake in Sokoto State | Yahaya ...

    African Journals Online (AJOL)

    A survey was conducted to determine the diversity and abundance of aquatic insects in Kware Lake, Kware local government area of Sokoto State from October to December, 2003. During these months, aquatic insects are associated mostly with permanent water bodies in Sokoto. Samples were obtained twice a week from ...

  14. A survey of potential bald eagle nesting habitat along the Great Lakes shoreline

    Science.gov (United States)

    William W. Bowerman; Teryl G. Grubb; Allen J. Bath; John P. Giesy; D.V. Chip Weseloh

    2005-01-01

    We used fixed-wing aircraft to survey the entire shoreline and connecting channels of the five Great Lakes to determine potential nesting habitat for bald eagles (Haliaeetus leucocephalus) during 1992. Habitat was classified as either good, marginal, or unsuitable, based on six habitat attributes: (a) tree cover, (b) proximity and (c) type/amount...

  15. A test of the Lake Habitat Survey method in Cleveland Reservoir ...

    African Journals Online (AJOL)

    The Lake Habitat Survey (LHS) method has only been applied once in a tropical African reservoir and could potentially be a useful tool for hydromorphological impact assessments. This study (October 2012) tested the application of the LHS method to two Zimbabwean reservoirs, Cleveland and Chivero, which are impacted ...

  16. Short Note: Preliminary fish survey of Lac Tseny in north- western ...

    African Journals Online (AJOL)

    Priority next steps at the lake include (i) additional surveys and biological studies of the endemic fish species and the Critically Endangered Madagascar big - headed turtle, Erymnochelys madagascariensis, (ii) clarification of the taxonomic status of Paretroplus cf. kieneri and, should it prove a new taxon, its formal scientific ...

  17. Quaternary Glacial Mapping in Western Wisconsin Using Soil Survey Information

    Science.gov (United States)

    Oehlke, Betsy M.; Dolliver, Holly A. S.

    2011-01-01

    The majority of soils in the western Wisconsin have developed from glacial sediments deposited during the Quaternary Period (2.6 million years before present). In many regions, multiple advances and retreats have left a complex landscape of diverse glacial sediments and landforms. The soils that have developed on these deposits reflect the nature…

  18. Results of a detailed infill lake-sediment survey in the Snow Lake area: Evaluation and comparison of grab sample and short core data

    Science.gov (United States)

    Friske, P.W.B.

    1996-01-01

    As part of the Exploration Science and Technology Initiative (EXTECH) program a detailed infill lake-sediment and water survey was undertaken in the Snow Lake area during the fall of 1991. This involved the collection of 346 lake sediment grab samples and concomitant waters. In 1993, additional work was undertaken involving the collection of 23 short cores from selected grab sample sites. The primary objectives of the infill survey and short core work were to: 1) evaluate the effectiveness of lake sediment geochemistry in detecting known mineralization in the Snow Lake area; 2) evaluate and develop new approaches in the use of lake sediment geochemistry; and, 3) define, if possible, new exploration targets. At most sites, data from the cores verify the original grab sample results. However, at a few sites the original anomalous grab sample results are interpreted as being related to contamination as opposed to naturally elevated levels. An unusually thick sequence of contaminated surface sediments with extremely high concentrations of trace metals is a likely contributing factor, a condition which is restricted to lakes in the immediate vicinity of local anthropogenic activity. Collection of lake cores provides a useful new approach to the follow-up of grab sample data and to the application of lake sediment geochemistry, particularly in areas with significant local contamination. Much of the known mineralization in the area is clearly reflected by the lake sediment data. Character of the anomalies mirror the composition of the nearby mineralization. The lake sediment data also identify a number of areas that warrant further investigation, several of which are discussed.

  19. An accuracy assessment of forest disturbance mapping in the western Great Lakes

    Science.gov (United States)

    P.L. Zimmerman; I.W. Housman; C.H. Perry; R.A. Chastain; J.B. Webb; M.V. Finco

    2013-01-01

    The increasing availability of satellite imagery has spurred the production of thematic land cover maps based on satellite data. These maps are more valuable to the scientific community and land managers when the accuracy of their classifications has been assessed. Here, we assessed the accuracy of a map of forest disturbance in the watersheds of Lake Superior and Lake...

  20. Electromagnetic Surveying in the Mangrove Lakes Region of Everglades National Park

    Science.gov (United States)

    Whitman, D.; Price, R.; Frankovich, T.; Fourqurean, J.

    2015-12-01

    The Mangrove Lakes are an interconnected set of shallow (~ 1m), brackish lake and creek systems on the southern margin of the Everglades adjacent to Florida Bay. Current efforts associated with the Comprehensive Everglades Restoration Plan (CERP) aim to increase freshwater flow into this region. This study describes preliminary results of geophysical surveys in the lakes conducted to assess changes in the groundwater chemistry as part of a larger hydrologic and geochemical study in the Everglades Lakes region. Marine geophysical profiles were conducted in Alligator Creek (West Lake) and McCormick Creek systems in May, 2014. Data included marine electromagnetic (EM) profiles and soundings, water depth measurements, surface water conductivity and salinity measurements. A GSSI Profiler EMP-400 multi-frequency EM conductivity meter continuously recorded in-phase and quadrature field components at 1, 8, and 15 KHz. The system was deployed in a flat bottomed plastic kayak towed behind a motorized skiff. Lake water depths were continuously measured with a sounder/chart plotter which was calibrated with periodic sounding rod measurements. At periodic intervals during the survey, the profiling was stopped and surface water conductivity, temperature and salinity are recorded with a portable YSI probe on the tow boat. Over 40,000 discrete 3-frequency EM measurements were collected. The data were inverted to 2-layer models representing the water layer thickness and conductivity and the lake bottom conductivity. At spot locations, models were constrained with water depth soundings and surface water conductivity measurements. At other locations along the profiles, the water depth and conductivity were allowed to be free, but the free models were generally consistent with the constrained models. Multilayer sub-bottom models were also explored but were found to be poorly constrained. In West Lake, sub-bottom conductivities decreased from 400 mS/m in the west to 200 mS/m in the

  1. Genetic analysis of historic western Great Lakes region wolf samples reveals early Canis lupus/lycaon hybridization.

    Science.gov (United States)

    Wheeldon, Tyler; White, Bradley N

    2009-02-23

    The genetic status of wolves in the western Great Lakes region has received increased attention following the decision to remove them from protection under the US Endangered Species Act. A recent study of mitochondrial DNA has suggested that the recovered wolf population is not genetically representative of the historic population. We present microsatellite genotype data on three historic samples and compare them with extant populations, and interpret published genetic data to show that the pre-recovery population was admixed over a century ago by eastern wolf (Canis lycaon) and grey wolf (Canis lupus) hybridization. The DNA profiles of the historic samples are similar to those of extant animals in the region, suggesting that the current Great Lakes wolves are representative of the historic population.

  2. Network global navigation satellite system surveys to harmonize American and Canadian datum for the Lake Champlain Basin

    Science.gov (United States)

    Flynn, Robert H.; Rydlund, Jr., Paul H.; Martin, Daniel J.

    2016-03-08

    Historically high flood levels were observed during flooding in Lake Champlain and the Richelieu River from late April through May 2011. Flooding was caused by record spring precipitation and snowmelt from the third highest cumulative snowfall year on record, which included a warm, saturated late spring snowpack. Flood stage was exceeded for a total of 67 days from April 13 to June 19, 2011. During this flooding, shoreline erosion and lake flood inundation were exacerbated by wind-driven waves associated with local fetch and lake-wide seiche effects. In May 2011, a new water-surface-elevation record was set for Lake Champlain. Peak lake-level water-surface elevations varied at the three U.S. Geological Survey lake-level gages on Lake Champlain in 2011. The May 2011 peak water-surface elevations for Lake Champlain ranged from 103.20 feet above the National Geodetic Vertical Datum of 1929 at the northern end of Lake Champlain (at its outlet into the Richelieu River at Rouses Point, New York) to 103.57 feet above the National Geodetic Vertical Datum of 1929 at the southern end of the Lake in Whitehall, New York. The water-surface elevations for the Richelieu River in Canada are referenced to a different vertical datum than are those in Lake Champlain in the United States, which causes difficulty in assessing real-time flood water-surface elevations and comparing of flood peaks in the Lake Champlain Basin in the United States and Canada.

  3. Class 1 overview of cultural resources for the Western Area Power Administration Salt Lake City Area Integrated Projects electric power marketing environmental impact statement

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, K.L.; Malinowski, L.M.; Hoffecker, J.F.; Walitschek, D.A.; Shogren, L.; Mathews, J.E.; Verhaaren, B.T.

    1993-11-01

    Argonne National Laboratory conducted an inventory of known archaeological and historic sites in areas that could be affected by the hydropower operation alternatives under analysis in the power marketing environmental impact statement for the Western Area Power Administration`s Salt Lake City Area Integrated Projects. The study areas included portions of the Green River (Flaming Gorge Dam to Cub Creek) in Utah and Colorado and the Gunnison River (Blue Mesa Reservoir to Crystal Dam) in Colorado. All previous archaeological surveys and previously recorded prehistoric and historic sites, structures, and features were inventoried and plotted on maps (only survey area maps are included in this report). The surveys were classified by their level of intensity, and the sites were classified according to their age, type, and contents. These data (presented here in tabular form) permit a general assessment of the character and distribution of archaeological remains in the study areas, as well as an indication of the sampling basis for such an assessment. To provide an adequate context for the descriptions of the archaeological and historic sites, this report also presents overviews of the environmental setting and the regional prehistory, history, and ethnography for each study area.

  4. Integrated geophysical survey for the geological structural and hydrogeothermal study of the North-western Gargano promontory (Southern Italy

    Directory of Open Access Journals (Sweden)

    D. Schiavone

    1996-06-01

    Full Text Available A multimethodological geophysical survey was performed in the north-western part of the Gargano promontory to study the geological structural setting and the underground fluid flow characteristics. The area has a complex tectonics with some magmatic outcrops and shallow low-enthalpy waters. Electrical, seismic reflection, gravimetric and magnetic surveys were carried out to reconstruct the geological structures; and in order to delineate the hydrogeothermal characteristics of the area, the self-potential survey was mainly used. Moreover magnetic and self-potential measurements were also performed in the Lesina lake. The joint three-dimensional interpretation of the geophysical data disclosed a large horst and graben structure covering a large part of the area. In the central part of the horst a large ramified volcanic body was modelled. The models show some intrusions rising from it to or near to the surface. The main structures are well deep-seated in the Crust and along them deep warm fluids rise as the SP data interpretation indicates.

  5. Characterization of fecal indicator bacteria in sediments cores from the largest freshwater lake of Western Europe (Lake Geneva, Switzerland).

    Science.gov (United States)

    Thevenon, Florian; Regier, Nicole; Benagli, Cinzia; Tonolla, Mauro; Adatte, Thierry; Wildi, Walter; Poté, John

    2012-04-01

    This study characterized the fecal indicator bacteria (FIB), including Escherichia coli (E. coli) and Enteroccocus (ENT), disseminated over time in the Bay of Vidy, which is the most contaminated area of Lake Geneva. Sediments were collected from a site located at ∼500 m from the present waste water treatment plant (WWTP) outlet pipe, in front of the former WWTP outlet pipe, which was located at only 300 m from the coastal recreational area (before 2001). E. coli and ENT were enumerated in sediment suspension using the membrane filter method. The FIB characterization was performed for human Enterococcus faecalis (E. faecalis) and Enterococcus faecium (E. faecium) and human specific bacteroides by PCR using specific primers and a matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Bacterial cultures revealed that maximum values of 35.2 × 10(8) and 6.6 × 10(6)CFU g(-1) dry sediment for E. coli and ENT, respectively, were found in the sediments deposited following eutrophication of Lake Geneva in the 1970s, whereas the WWTP started operating in 1964. The same tendency was observed for the presence of human fecal pollution: the percentage of PCR amplification with primers ESP-1/ESP-2 for E. faecalis and E. faecium indicated that more than 90% of these bacteria were from human origin. Interestingly, the PCR assays for specific-human bacteroides HF183/HF134 were positive for DNA extracted from all isolated strains of sediment surrounding WWPT outlet pipe discharge. The MALDI-TOF MS confirmed the presence of general E. coli and predominance E. faecium in isolated strains. Our results demonstrated that human fecal bacteria highly increased in the sediments contaminated with WWTP effluent following the eutrophication of Lake Geneva. Additionally, other FIB cultivable strains from animals or adapted environmental strains were detected in the sediment of the bay. The approaches used in this research are valuable to assess the

  6. Unplanned roads impacts assessment in Phewa Lake watershed, Western region, Nepal

    Science.gov (United States)

    Leibundgut, Geoffroy; Sudmeier-Rieux, Karen; Devkota, Sanjaya; Jaboyedoff, Michel; Penna, Ivanna; Adhikari, Anu; Khanal, Rajendra

    2015-04-01

    This work describes current research being conducted in the Phewa Lake watershed, near Pokhara in Nepal's Siwaliks/Middle hills, a moist sub-tropical zone with the highest amount of annual rainfall in Nepal (4,500 - 5,000 mm). The watershed lithology is mainly siltstone, sandstones and intensively weathered rocks, highly prone to erosion and shallow landslides (Agrawala et al., 2003). The main purpose of this study is to focus on the impact of unplanned earthen road construction in the Phewa Lake watershed as part of land use changes over 30 years in one of Nepal's most touristic regions. Over the past three decades, the road network has expanded exponentially and a majority of rural earthen roads are often funded by communities themselves, with some government subsidies. They are usually constructed using a local bulldozer contractor with no technical or geological expertise increasing erosion processes, slope instabilities risk and impacts to settlements, forests, water sources, agriculture lands, and infrastructure. Moreover, these human-induced phenomena are being compounded by increasingly intense monsoon rains, likely due to climate change (Petley, 2010). Research methods were interdisciplinary and based on a combination of remote sensing, field observations and discussions with community members. The study compared 30 year-old aerial photos with current high resolution satellite images to correlate changes in land use with erosion and slope instabilities. Secondly, most of the watershed's roads were surveyed in order to inventory and quantify slope instabilities and soil loss events. Using a failure-characteristics grid, their main features were measured (location, size, type and extension of damage areas, etc.) and a GIS data base was created. We then estimated economic impacts of these events in terms of agriculture lands losses and road maintenance, based on field observations and discussions with affected people. Field work investigations have shown that

  7. Sample Archaeological Survey of Public Use Areas, Milford Lake, Kansas

    Science.gov (United States)

    1982-09-01

    basic data on Schultz focus mortuary practices and the physical characteristics of these Indians. Dr. Carlyle Smith’s students, in the Department of...destruction of the original topography. The third areas are the public recreation aieas. These sites have been 0 under construction for roads, toilets , picnic...34 In Explorations into Cahokia Archaeology, edited by Melvin L. Fowler. Bulletin 7, Illinois Archaeological Survey, Urbana. 1969. "Valley Focus Mortuary

  8. SPATIAL PATTERNS OF WATER QUALITY AND PLANKTON FROM HIGH-RESOLUTION CONTINUOUS IN SITU SENSING ALONG A 537-KM NEARSHORE TRANSECT OF WESTERN LAKE SUPERIOR, 2004

    Science.gov (United States)

    A demonstration that the adaptation of electronic instrumentation and towed survey strategies are effective in providing rapid, spatially extensive, and cost effective data for assessment of the Great Lakes.

  9. CONFIRMATORY SURVEY REPORT FOR THE SECTION 4 AREA AT THE RIO ALGOM AMBROSIA LAKE FACILITY NEW MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    W.C. Adams

    2010-02-12

    The objectives of the confirmatory survey were to verify that remedial actions were effective in meeting established release criteria and that documentation accurately and adequately described the final radiological conditions of the RAM Ambrosia Lake, Section 4 Areas.

  10. First numerical ages from the northern lake Chapala shoreline, western Mexico, and their importance for palaeontology and archaeology

    Science.gov (United States)

    Kadereit, Annette; Dewitt, Regina; Terrazas, Alejandro; Stinnesbeck, Wolfgang; Zipf, Lars; Schukraft, Gerd

    2017-04-01

    Lake Chapala in the central-western Mexican state of Jalisco is the successor of the late-Miocene to early Pleistocene palaeo-lake Jalisco and is situated in an active neotectonic basin at approximately 1500 m above sea level. It presently covers an area of ca. 1100 km2 and represents Mexico's largest freshwater reservoir. As water depth reaches only a few meters the position of its shorelines has fluctuated substantially throughout the lake's history due to volcanic and tectonic activity as well as climate fluctuations. One of the more recently abandoned shorelines is preserved on the northern shoreline east of Ajijic at San Antonio Tlayacapan (SAT), where sand and silt deposits crop out at the present waterline. The beach sediments at SAT are famous for their fossils of late Wisconsian age (e.g. ground sloths, gomphotheriids), but also host human osteological remains, which are now housed in the Museo de Paleontología de Guadalajara, in the state capital. Numeric dating of sediments from Lake Chapala has proven to be exceedingly difficult as bones are heavily mineralized by Fe-Mn-oxides. In addition, input of ancient carbon exists from hydrothermal sources deep underneath the lake bottom and its distribution throughout the lake-water body, with currents driven by easterly winds and respective counter-currents, leading to age inversions for 14C-dating (Zárate-del-Valle et al. 2011). As 14C radiometric methods are thus shown to be problematic we here tested the possibility of optical stimulated luminescence (OSL) dating. Diverse tests showed that the samples were not adequate for coarse-grain quartz dating or post infrared stimulated (post-IR) blue-light stimulated (BLSL) dating of polymineral fine grains. The blue emission band of the infrared stimulated luminescence (IRSL) signal of the natural samples has been proven to be quite dim, so that a single aliquot regeneration (SAR) protocol (Murray & Wintle 2000) was not suitable. Finally, we applied a traditional

  11. Modeling detection probability to improve marsh bird surveys in southern Canada and the Great Lakes states

    Directory of Open Access Journals (Sweden)

    Douglas C. Tozer

    2016-12-01

    Full Text Available Marsh birds are notoriously elusive, with variation in detection probability across species, regions, seasons, and different times of day and weather. Therefore, it is important to develop regional field survey protocols that maximize detections, but that also produce data for estimating and analytically adjusting for remaining differences in detections. We aimed to improve regional field survey protocols by estimating detection probability of eight elusive marsh bird species throughout two regions that have ongoing marsh bird monitoring programs: the southern Canadian Prairies (Prairie region and the southern portion of the Great Lakes basin and parts of southern Québec (Great Lakes-St. Lawrence region. We accomplished our goal using generalized binomial N-mixture models and data from ~22,300 marsh bird surveys conducted between 2008 and 2014 by Bird Studies Canada's Prairie, Great Lakes, and Québec Marsh Monitoring Programs. Across all species, on average, detection probability was highest in the Great Lakes-St. Lawrence region from the beginning of May until mid-June, and then fell throughout the remainder of the season until the end of June; was lowest in the Prairie region in mid-May and then increased throughout the remainder of the season until the end of June; was highest during darkness compared with light; and did not vary significantly according to temperature (range: 0-30°C, cloud cover (0%-100%, or wind (0-20 kph, or during morning versus evening. We used our results to formulate improved marsh bird survey protocols for each region. Our analysis and recommendations are useful and contribute to conservation of wetland birds at various scales from local single-species studies to the continental North American Marsh Bird Monitoring Program.

  12. Diurnal to annual changes in latent, sensible heat, and CO2 fluxes over a Laurentian Great Lake: A case study in Western Lake Erie

    Science.gov (United States)

    Shao, Changliang; Chen, Jiquan; Stepien, Carol A.; Chu, Housen; Ouyang, Zutao; Bridgeman, Thomas B.; Czajkowski, Kevin P.; Becker, Richard H.; John, Ranjeet

    2015-08-01

    To understand the carbon and energy exchange between the lake surface and the atmosphere, direct measurements of latent, sensible heat, and CO2 fluxes were taken using the eddy covariance (EC) technique in Western Lake Erie during October 2011 to September 2013. We found that the latent heat flux (LE) had a marked one-peak seasonal change in both years that differed from the diurnal course and lacked a sinusoidal dynamic common in terrestrial ecosystems. Daily mean LE was 4.8 ± 0.1 and 4.3 ± 0.2 MJ m-2 d-1 in Year 1 and Year 2, respectively. The sensible heat flux (H) remained much lower than the LE, with a daily mean of 0.9 ± 0.1 and 1.1 ± 0.1 MJ m-2 d-1 in Year 1 and Year 2, respectively. As a result, the Bowen ratio was year period, with the lowest summer value at 0.14. The vapor pressure deficit explained 35% of the variation in half hourly LE, while the temperature difference between the water surface and air explained 65% of the variation in half hourly H. Western Lake Erie acted as a small carbon sink holding -19.0 ± 5.4 and -40.2 ± 13.3 g C m-2 in the first and second summers (May-September) but as an annual source of 77.7 ± 18.6 and 49.5 ± 17.9 g C m-2 yr-1 in Year 1 and Year 2, respectively. The CO2 flux (FCO2) rate varied from -0.45 g C m-2 d-1 to 0.98 g C m-2 d-1. Similar to LE, FCO2 had noticeable diurnal changes during the months that had high chlorophyll a months but not during other months. A significantly negative correlation (P gap-filling methods, including marginal distribution sampling, mean diurnal variation, and monthly mean, were quantitatively assessed, yielding an uncertainty of 4%, 6%, and 10% in LE, H, and FCO2, respectively.

  13. CHAPHOLO (scientific drilling project): Paleolimnological Evaluation of Lake Chapala, western Mexico, During Holocene (CONACYT grant: CB2011-168685)

    Science.gov (United States)

    Zarate, P. F.; Fritz, S. C.; Ramirez Sanchez, U.; Gomez Salazar, S.; Ceja Andrade, I.; Priyadarsi Debajyoti, R.; Brenner, M.

    2012-12-01

    CHAPHOLO ( CHAP: Chapala; HOLO: Holocene) has as goal to evaluate paleoenvironmental variations recorded in the sediment of neotectonic Lake Chapala (LCH), western Mexico (20°15.129'N, 103° 02.996'W). The lake lies about 1524 m asl. LCH is the largest lake in Mexico (1,100 kmyr2), but is shallow (zmax = 7.20 m). It is located in a basin belonging to the Citala Rift, the east-west branch of three continental rifts that join to form the so-called Jalisco triple junction. Our working hypothesis is that recent (Holocene) paleolimnological changes in LCH were caused by major climate variations and by minor regional/local processes (e.g. volcanism). We will drill a 40m long core from the lake depocenter, with the objective of recovering a full Holocene record, and likely more, assuming a mean sedimentation rate of 2 mm yr-1. Core chronology will be established using AMS 14C and 210Pb techniques and climate inferences will be made using geochemical, geophysical and micropaleontological proxies. Particularly, we pretend to identify the six "short" fluctuations of climate that characterized the Holocene (Mayewski et al., 2004) and the identification of Mediewal Warm Period and the droughts affected the mayan culture (Hodell et al., 1995). We will verify the application of Ti as a proxy to rainfall (Metcalfe et al., 2010). During the last 10,000 the fact about the dissolution of diatom in LCH sediments must be evaluated (Ryves et al., 2009). The working group is multidisciplinary (Geochemistry, Micropaleontology, Paleolimnology, Geophysics) and involves multiple institutions (Guadalajara University, Mexican National University-UNAM, University of Florida, University of Nebraska-Lincoln). CHAPHOLO is supported by funds from the Mexican government and from the Guadalajara University. The theme of CHAPHOLO is consistent with global environmental programs such as PAGES and CLIVAR. This project will be developed in stages over three years.

  14. The Effect of Algal Blooms on Carbon Emissions in Western Lake Erie: An Integration of Remote Sensing and Eddy Covariance Measurements

    Directory of Open Access Journals (Sweden)

    Zutao Ouyang

    2017-01-01

    Full Text Available Lakes are important components for regulating carbon cycling within landscapes. Most lakes are regarded as CO2 sources to the atmosphere, except for a few eutrophic ones. Algal blooms are common phenomena in many eutrophic lakes and can cause many environmental stresses, yet their effects on the net exchange of CO2 (FCO2 at large spatial scales have not been adequately addressed. We integrated remote sensing and Eddy Covariance (EC technologies to investigate the effects that algal blooms have on FCO2 in the western basin of Lake Erie—a large lake infamous for these blooms. Three years of long-term EC data (2012–2014 at two sites were analyzed. We found that at both sites: (1 daily FCO2 significantly correlated with daily temperature, light, and wind speed during the algal bloom periods; (2 monthly FCO2 was negatively correlated with chlorophyll-a concentration; and (3 the year with larger algal blooms was always associated with lower carbon emissions. We concluded that large algal blooms could reduce carbon emissions in the western basin of Lake Erie. However, considering the complexity of processes within large lakes, the weak relationship we found, and the potential uncertainties that remain in our estimations of FCO2 and chlorophyll-a, we argue that additional data and analyses are needed to validate our conclusion and examine the underlying regulatory mechanisms.

  15. Acid Rain Effects on Adirondack Streams - Results from the 2003-05 Western Adirondack Stream Survey (the WASS Project)

    Science.gov (United States)

    Lawrence, Gregory B.; Roy, Karen M.; Baldigo, Barry P.; Simonin, Howard A.; Passy, Sophia I.; Bode, Robert W.; Capone, Susan B.

    2009-01-01

    Traditionally lakes have been the focus of acid rain assessments in the Adirondack region of New York. However, there is a growing recognition of the importance of streams as environmental indicators. Streams, like lakes, also provide important aquatic habitat, but streams more closely reflect acid rain effects on soils and forests and are more prone to acidification than lakes. Therefore, a large-scale assessment of streams was undertaken in the drainage basins of the Oswegatchie and Black Rivers; an area of 4,585 km2 in the western Adirondack region where acid rain levels tend to be highest in New York State.

  16. Using public participation to sample trace metals in lake surface sediments: the OPAL Metals Survey.

    Science.gov (United States)

    Turner, S D; Rose, N L; Goldsmith, B; Bearcock, J M; Scheib, C; Yang, H

    2017-05-01

    Members of the public in England were invited in 2010 to take part in a national metals survey, by collecting samples of littoral sediment from a standing water body for geochemical analysis. To our knowledge, this is the first national sediment metals survey using public participation and reveals a snapshot of the extent of metals contamination in ponds and lakes across England. Hg, Ni, Cu, Zn and Pb concentrations exceeding sediment quality guidelines for the health of aquatic biota are ubiquitous in ponds and lakes, not just in areas with a legacy of industrial activity. To validate the public sampling approach, a calibration exercise was conducted at ten water bodies selected to represent a range of lakes found across England. Sediment concentrations of Hg, Ni, Cu, Zn and Pb were measured in samples of soil, stream and littoral and deep water sediment to assess inputs. Significant differences between littoral sediment metal concentrations occur due to local variability, but also organic content, especially in upland, peat soil catchments. Variability of metal concentrations between littoral samples is shown to be low in small (complex inputs and variation in organic content of littoral samples have a greater variability. Collection of littoral sediments in small lakes and ponds, with or without voluntary participation, can provide a reliable sampling technique for the preliminary assessment of metal contamination in standing waters. However, the heterogeneity of geology, soils and history/extent of metal contamination in the English landscape, combined with the random nature of sample collection, shows that systematic sampling for evaluating the full extent of metal contamination in lakes is still required.

  17. Survey of bioactive components in Western Canadian berries.

    Science.gov (United States)

    Bakowska-Barczak, Anna M; Marianchuk, Myles; Kolodziejczyk, Paul

    2007-11-01

    Berries native to Western Canada were analyzed for total anthocyanins, total phenolics, and trolox equivalent antioxidant activity (TEAC). Values ranged from 1.60 to 9.55 mmol trolox equivalent per 100 g fresh mass. Anthocyanin content ranged from 41.6 (in red twinberries) to 1081 mg cyanidin-3-glucoside equivalents per 100 g fresh mass (in honeysuckle fruits). Honeysuckle fruits contained the highest amount of total polyphenols, 1111 mg gallic acid equivalents per 100 g, among analyzed fruits. Additionally, anthocyanins in the investigated berries were identified and characterized by HPLC - electrospray ionization - tandem mass spectrometric method coupled with diode array detection. The number of anthocyanins varied from 4 in saskatoon berries (Amelanchier alnifolia Nutt.) to 20 in bilberries (Vaccinum myrtilloides Michx.). In all the samples analyzed, 6 common anthocyanidins:, cyanidin, delphinidin, pelargonidin, petunidin, peonidin, and malvidin, were found. Half the analyzed berries contained acylated anthocyanins, but a significant amount was found only in bilberries. The analyzed berry seed oils contained high amounts of unsaturated fatty acids (over 90%), but only the golden currant seed oil contained gamma-linolenic acid.

  18. Field Surveys, IOC Valleys. Volume III, Part I. Cultural Resources Survey, Dry Lake Valley, Nevada.

    Science.gov (United States)

    1981-08-01

    Delmues (or Swiss Bob) Well where there was a station, then west across Dry Lake Valley toward Coyote Spring to another station (Lloyd, 1980). The line...in the recorded surface assemblages of the temporary camps. Further investigations may $ Etag E-TR-48-III-I 120 clarify the specific nature of the

  19. The effect of water quality on the distribution of macro-benthic fauna in Western Lagoon and Timsah Lake, Egypt.I

    Directory of Open Access Journals (Sweden)

    Aisha Ahmed M. Belal

    2016-12-01

    Full Text Available Macro-benthic fauna are considered the good bio-indicators for the environmental changes of any aquatic ecosystems. Samples of macro-benthos, sediments and surface water were collected from 13 stations representing different conditions in the Western Lagoon (10 stations and Timsah Lake (3 stations from autumn 2014 to summer 2015. Macro-benthic density and diversity in Timsah Lake were higher than those in the Western Lagoon; the density at Timsah Lake encompassed 167,649 individual/m2 representing 42 species from the total of 46 species recorded in the investigated area. While species density in the Western Lagoon constituted 12,008 individual/m2 presenting only 16 species. Winter recorded the highest density (74,854 individual/m2; the highest dominance (CDI = 0.858 and the lowest Equitability (0.293 due to the dominance of the opportunistic species. Spring harvested both the highest diversity (28 species and species richness (SR = 2.917. While autumn and summer procured both the lowest density and diversity (34,021 and 29,544 individual/m2 and 23 and 25 species respectively. The equitability index (E′ showed its highest values within the Western Lagoon (>0.90 owing to the species poorness relative to Timsah Lake. The water quality data showed that the Western Lagoon and Timsah Lake had significant high oxygen influx in spring (11.00 and 9.35 mg/l, respectively and oxygen depletion in summer (1.00 and 3.00 mg/l, respectively. Reactive phosphorus and ammonia in the Western Lagoon exceeded the world averages. Timsah Lake sediments were highly affected by the sediment drifts from the Western Lagoon. The highest influx of the fine sediment group (FSG was estimated during spring with an average of 62.77% and 61.18% in Timsah Lake and Western Lagoon, respectively. Total organic matter (TOM in Western Lagoon recorded the highest average of 17.05% in spring accompanied with the high biological productivities.

  20. Mercury bioaccumulation in fishes from subalpine lakes of the Wallowa-Whitman National Forest, northeastern Oregon and western Idaho

    Science.gov (United States)

    Eagles-Smith, Collin A.; Herring, Garth; Johnson, Branden L.; Graw, Rick

    2013-01-01

    Mercury (Hg) is a globally distributed pollutant that poses considerable risks to human and wildlife health. Over the past 150 years since the advent of the industrial revolution, approximately 80 percent of global emissions have come from anthropogenic sources, largely fossil fuel combustion. As a result, atmospheric deposition of Hg has increased by up to 4-fold above pre-industrial times. Because of their isolation, remote high-elevation lakes represent unique environments for evaluating the bioaccumulation of atmospherically deposited Hg through freshwater food webs, as well as for evaluating the relative importance of Hg loading versus landscape influences on Hg bioaccumulation. The increase in Hg 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 Hg emissions may propagate to changes in Hg bioaccumulation and ecological risk. In this study, we evaluated Hg concentrations in fishes of high-elevation, sub-alpine lakes in the Wallowa-Whitman National Forest in northeastern Oregon and western Idaho. Our goals were to (1) assess the magnitude of Hg contamination in small-catchment lakes to evaluate the risk of atmospheric Hg to human and wildlife health, (2) quantify the spatial variability in fish Hg concentrations, and (3) determine the ecological, limnological, and landscape factors that are best correlated with fish total mercury (THg) concentrations in these systems. Across the 28 study lakes, mean THg concentrations of resident salmonid fishes varied as much as 18-fold among lakes. Importantly, our top statistical model explained 87 percent 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. The basal area of conifers

  1. Survey and habitat data for postbreeding lesser scaup, Lower Red Rock Lake, MT, 2007-2013

    Science.gov (United States)

    Austin, Jane E.; Warren, Jeffrey

    2016-01-01

    The data are part of a larger, long-term project of lesser scaup on Lower Red Rock Lake, Montana, 2004-2015, conducted by the US Fish and Wildlife Service. This segment of the data has summarized results of late summer resighting surveys of nasal-marked adult females and GIS-derived habitat attributes. Scaup resighting surveys were conducted mid-August to early September, 2007-2013. The study site was divided into 16 survey plots (as shown as grid in figure); each plot comprised one to four 750 × 750 m survey blocks such that plots contained roughly equivalent area of open water Survey data included GPS location, number, and social status of marked females, wind conditions, and group size of other scaup associated with a marked bird. Each record is one resight session. Habitat attributes were derived from annual lake-level data (water depth) and analyses of 2008 aerial imagery (percent open area, viewshed, interface of water:emergent vegetation, percent bare aquatic substrate, fetch distance). Both types of GIS data were delineated at the cell (quarter-block) scale (375 x 375m).

  2. Mercury in the sediments of Vembanad Lake, western coast of India.

    Science.gov (United States)

    Mohan, Mahesh; Chandran, M S Shylesh; Jayasooryan, K K; Ramasamy, E V

    2014-06-01

    Mercury, a global pollutant, is popping up in places where it was never expected before and it burdens in sediments and other non-biological materials. It is estimated to have increased up to five times the pre-human level due to anthropogenic activities. Vembanad backwaters, one of the largest Ramsar site in India, which have extraordinary importance for its hydrological function, are now considered as one of the mercury hot spots in India. In this study, surface sediment samples of Vembanad Lake and nearshore areas have been seasonally analysed for total mercury and methyl mercury concentrations while the core sediment samples were analysed for total mercury. The results showed that the northern part of the lake was more contaminated with mercury than the southern part. The mercury concentration was relatively high in the subsurface sediment samples, indicating the possibility of historic industrial mercury deposition. A decreasing trend in the mercury level towards the surface in the core sediment was also observed. The geochemical parameters were also analysed to understand the sediment mercury chemistry. Anoxic conditions, pH and organic carbon, sulphur and Fe determined the presence of various species of mercury in the sediments of Vembanad Lake. The prevailing physical and geochemical conditions in Vembanad Lake have indicated the chances of chemical transformation of mercury and the potential hazard if the deposited mercury fractions are remobilised.

  3. Late Miocene episodic lakes in the arid Tarim Basin, western China.

    Science.gov (United States)

    Liu, Weiguo; Liu, Zhonghui; An, Zhisheng; Sun, Jimin; Chang, Hong; Wang, Ning; Dong, Jibao; Wang, Huanye

    2014-11-18

    The Tibetan Plateau uplift and Cenozoic global cooling are thought to induce enhanced aridification in the Asian interior. Although the onset of Asian desertification is proposed to have started in the earliest Miocene, prevailing desert environment in the Tarim Basin, currently providing much of the Asian eolian dust sources, is only a geologically recent phenomenon. Here we report episodic occurrences of lacustrine environments during the Late Miocene and investigate how the episodic lakes vanished in the basin. Our oxygen isotopic (δ(18)O) record demonstrates that before the prevailing desert environment, episodic changes frequently alternating between lacustrine and fluvial-eolian environments can be linked to orbital variations. Wetter lacustrine phases generally corresponded to periods of high eccentricity and possibly high obliquity, and vice versa, suggesting a temperature control on the regional moisture level on orbital timescales. Boron isotopic (δ(11)B) and δ(18)O records, together with other geochemical indicators, consistently show that the episodic lakes finally dried up at ∼4.9 million years ago (Ma), permanently and irreversibly. Although the episodic occurrences of lakes appear to be linked to orbitally induced global climatic changes, the plateau (Tibetan, Pamir, and Tianshan) uplift was primarily responsible for the final vanishing of the episodic lakes in the Tarim Basin, occurring at a relatively warm, stable climate period.

  4. Late Miocene episodic lakes in the arid Tarim Basin, western China

    Science.gov (United States)

    Liu, Weiguo; Liu, Zhonghui; An, Zhisheng; Sun, Jimin; Chang, Hong; Wang, Ning; Dong, Jibao; Wang, Huanye

    2014-01-01

    The Tibetan Plateau uplift and Cenozoic global cooling are thought to induce enhanced aridification in the Asian interior. Although the onset of Asian desertification is proposed to have started in the earliest Miocene, prevailing desert environment in the Tarim Basin, currently providing much of the Asian eolian dust sources, is only a geologically recent phenomenon. Here we report episodic occurrences of lacustrine environments during the Late Miocene and investigate how the episodic lakes vanished in the basin. Our oxygen isotopic (δ18O) record demonstrates that before the prevailing desert environment, episodic changes frequently alternating between lacustrine and fluvial-eolian environments can be linked to orbital variations. Wetter lacustrine phases generally corresponded to periods of high eccentricity and possibly high obliquity, and vice versa, suggesting a temperature control on the regional moisture level on orbital timescales. Boron isotopic (δ11B) and δ18O records, together with other geochemical indicators, consistently show that the episodic lakes finally dried up at ∼4.9 million years ago (Ma), permanently and irreversibly. Although the episodic occurrences of lakes appear to be linked to orbitally induced global climatic changes, the plateau (Tibetan, Pamir, and Tianshan) uplift was primarily responsible for the final vanishing of the episodic lakes in the Tarim Basin, occurring at a relatively warm, stable climate period. PMID:25368156

  5. The origin and evolution of Iskanderkul Lake in the western Tien Shan and related geomorphic hazards

    Czech Academy of Sciences Publication Activity Database

    Emmer, Adam; Kalvoda, J.

    2017-01-01

    Roč. 99, č. 2 (2017), s. 139-154 ISSN 0435-3676 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:86652079 Keywords : iskanderkul lake * rockslide dam * outburst flood * tien shan Subject RIV: EH - Ecology, Behaviour Impact factor: 1.302, year: 2016

  6. Recent decadal glacier mass balances over the Western Nyainqentanglha Mountains and the increase in their melting contribution to Nam Co Lake measured by differential bistatic SAR interferometry

    Science.gov (United States)

    Li, Gang; Lin, Hui

    2017-02-01

    The Western Nyainqentanglha Mountains locates in the southeastern center of the Inner Tibetan Plateau (ITP). Glaciers in this region are influenced by both the continental climate of Central Asia and the Indian Monsoon system. Their melting on the western slopes feeds the Nam Co Lake, which is the second largest endorheic lake in the ITP. The elevation of Nam Co Lake increased at a rate of 0.25 ± 0.12 m year- 1 from 2003 to 2009. In this study, aimed at quantifying the decadal glacier mass balance in the Western Nyainqentanglha Mountains and their increasing melting contribution to Nam Co Lake; we applied the differential Bistatic SAR interferometry method to five pairs of TanDEM CoSSC datasets observed between 2013 and 2014 and SRTM acquired in 2000. The mean annual mass loss rate was - 0.235 ± 0.127 m w.e. year- 1 for the entire range. The mass loss rate for the northwestern slope (inside the Nam Co Lake drainage basin) and the southeastern slope (outside the Nam Co Lake drainage basin) were - 0.268 ± 0.129 m w.e. year- 1 and ¬ 0.219 ± 0.126 m w.e. year- 1, respectively. Our results agree well with previous fieldwork at the Zhadang and Gurenhekou glaciers located on the northwestern and southeastern slopes. Debris-cover suppressed glacier downwasting to some extent. By presuming that all of the melted ice flows into the lake, the glaciers' melting contribution to Nam Co Lake's increasing water volume was approximately 10.50 ± 9.00% during the period between 2003 and 2009.

  7. Feeding of western gray whales during a seismic survey near Sakhalin Island, Russia

    OpenAIRE

    Yazvenko, S. B.; McDonald, T. L.; Blokhin, S. A.; Johnson, S. R.; Melton, H. R.; Newcomer, M. W.; Nielson, R.; Wainwright, P. W.

    2007-01-01

    Exxon Neftegas Limited, as operator of the Sakhalin-1 consortium, is developing oil and gas reserves on the continental shelf off northeast Sakhalin Island, Russia. DalMorNefteGeofizika (DMNG) on behalf of the Sakhalin-1 consortium conducted a 3-D seismic survey of the Odoptu license area during 17 August? September 2001. A portion of the primary feeding area of the endangered western gray whale (Eschrichtius robustus) is located in the vicinity of the seismic survey. This paper presents data...

  8. Serologic survey for viral and bacterial infections in western populations of Canada Lynx (Lynx canadensis)

    Science.gov (United States)

    Roman Biek; Randall L. Zarnke; Colin Gillin; Margaret Wild; John R. Squires; Mary Poss

    2002-01-01

    A serologic survey for exposure to pathogens in Canada lynx (Lynx canadensis) in western North America was conducted. Samples from 215 lynx from six study areas were tested for antibodies to feline parvovirus (FPV), feline coronavirus, canine distemper virus, feline calicivirus, feline herpesvirus, Yersinia pestis, and Francisella tularensis. A subset of...

  9. Swath bathymetric survey of Englebright Lake, Yuba-Nevada Counties, California

    Science.gov (United States)

    Childs, Jonathan R.; Stevenson, Andrew J.

    2006-01-01

    In March, 2004, the USGS conducted a swath bathymetric survey of Englebright Lake, a 9-mile long reservoir located in the Sierra Nevada foothills of northern California on the Yuba River. This survey was follow-on to an earlier bathymetric survey and sediment thickness analysis done by the USGS in 2001 (Childs and others, 2003). The primary purpose of these studies is to assess the quantity and nature of the sediment that has accumulated since the dam was completed in 1940. The specific purpose of the swath bathymetry was to map in high detail the prograding delta that is being formed as the lake fills in with sediment. In the event of another large flood such as occurred on January 1, 1997, the survey could be repeated to determine the effect of such an event on the sediment volume and distribution. This study was conducted under the auspices of the Upper Yuba River Studies Program (UYRSP) . The UYRSP is funded by the CALFED Bay-Delta Program, whose mission is to "develop and implement a long-term comprehensive plan that will restore ecological health and improve water management for beneficial uses of the San Francisco Bay-Delta System".

  10. Bathymetric evolution of Tasman Glacier terminal lake, New Zealand, as determined by remote surveying techniques

    Science.gov (United States)

    Purdie, Heather; Bealing, Paul; Tidey, Emily; Gomez, Christopher; Harrison, Justin

    2016-12-01

    Processes that drive iceberg calving at the margins of freshwater terminating glaciers are still poorly understood. This knowledge-gap is in part due to the challenge of obtaining good in situ data in a highly dynamic and dangerous environment. We are using emerging remote technologies, in the form of a remote controlled jet boat to survey bathymetry, and Structure from Motion (SfM) to characterize terminus morphology, to better understand relationships between lake growth and terminus evolution. Comparison of results between the jet boat mounted dual-frequency Garmin fish-finder with an Odom Echotrac DF3200 MKII with 200/38 kHz dual-frequency transducer, showed that after a sound velocity adjustment, the remote survey obtained depth data within ± 1 m of the higher grade survey equipment. Water depths of up to 240 m were recorded only 100 m away from the terminus, and subaerial cliff height ranged from around 6 to 33 m, with the central region of the terminus more likely to experience buoyancy. Subaqueous ice ramps are ephemeral features, and in 2015 multiple ice ramps extended out into the lake from the terminus by 100-200 m. The consistent location of some of the subaqueous ramps between surveys may indicate that other processes, for example, subglacial hydrology, also influence evolving terminus morphology.

  11. Relationships between Western Area Power Administration`s power marketing program and hydropower operations at Salt Lake City area integrated projects

    Energy Technology Data Exchange (ETDEWEB)

    Veselka, T.D.; Folga, S.; Poch, L.A. [and others

    1995-03-01

    This technical memorandum provides background information on the Western Area Power Administration (Western) and the physical characteristics of the Salt Lake City Area Integrated Projects (SLCA/IP) hydropower plants, which include the Colorado River Storage Project, the Rio Grande Project, and the Collbran Project. In addition, the history, electrical capacity, storage capacity, and flow restrictions at each dam are presented. An overview of Western`s current programs and services, including a review of statutory authorities, agency discretion, and obligations, is also provided. The variability of SLCA/IP hourly generation under various alternative marketing strategies and purchasing programs is discussed. The effects of Western`s services, such as area load control, outage assistance, and transmission, on SLCA/IP power plant operations are analyzed.

  12. Palynology and Archaeology of Late Vistulian and Early Holocene Sites in Lubuskie Lake District, Western Poland

    Directory of Open Access Journals (Sweden)

    Okuniewska-Nowaczyk Iwona

    2014-04-01

    Full Text Available The Lubuskie Lake District played an important part in recolonisation of the Polish Plain due to its location and the character of the terrain. Despite that, it is and especially its northern part, poorly explored regarding both history of Late Glacial and early Holocene settlements, and the natural environment. The paper presents results of multidisciplinary research in this area. The most spectacular discoveries were connected with remains of settlements of the Hamburgian culture societies at Myszęcin - currently the richest site of this culture over the entire North European Plain. In the vicinity of this site several Late Palaeolithic and Mesolithic settlements of varied functions were recorded. First palynological records came from the Younger Dryas sediments in this area. In a log with a palynological spectrum comprising Younger Dryas and the beginning of the Holocene, a charcoal dust was found and it could indicate human activity as humans lived at a lake shore. An important complement to the image of the Late Glacial settlement at the Lubuskie Lake District was provided by the research near Lubrza that resulted in data regarding settlements of the Federmesser and Świderian culture societies. This region was not typical in a palynological spectrum of deposits during Allerød but also indicated highly diversified thickness of basal peat in a small area.

  13. Behavioural responses of western gray whales to a 4-D seismic survey off northeastern Sakhalin Island, Russia

    NARCIS (Netherlands)

    Gailey, Glenn; Sychenko, Olga; McDonald, Trent; Racca, Roberto; Rutenko, Alexander; Bröker, Koen

    2016-01-01

    A seismic survey was conducted off the northeastern coast of Sakhalin Island, Russia in 2010. The survey area was adjacent to the only known near-shore feeding ground of the Critically Endangered population of western gray whales Eschrichtius robustus in the western Pacific south of the Aleutian

  14. Assessing the environmental/human risk of potential genotoxicants in water samples from lacustrine ecosystems: The case of lakes in Western Greece.

    Science.gov (United States)

    Vlastos, Dimitris; Dailianis, Stefanos; Kindou, Aggeliki; Antonopoulou, Maria; Gianni, Areti; Zacharias, Ierotheos

    2017-01-01

    Lakes, representing major freshwater resources, play a crucial role for both humans and ecosystems. Based on the increasing international interest in the contamination of water resources by genotoxic compounds, the present study aimed to evaluate the genotoxic potential of surface water samples collected from the five (5) lakes (Amvrakia, Lysimachia, Ozeros, Trichonida, Kastraki) located in Aitoloakarnania regional unit (Western Greece). The genotoxic potential of surface water samples was evaluated by employing the Cytokinesis Block MicroNucleus (CBMN) assay in cultured human lymphocytes. In the former assay, lymphocytes were treated with 1, 2 and 5% (v/v) of surface water from each lake. Statistically significant differences (1.7 to 3.3 fold increase in MN frequencies vs. the control) were seen at the dose of 5% (v/v) in all studied lakes. At the dose of 2% (v/v) statistically significant differences (1.7 to 2.6 fold increase in MN frequencies vs. the control) were observed in all studied lakes except Trichonida lake. Finally, at the dose of 1% (v/v) statistically significant differences (2.3 and 2.5 fold increase in MN frequencies vs. the control) were observed in the Ozeros and Lysimachia lakes. The evaluation of the potential genotoxic effects and the analysis of the physicochemical parameters of lakes' surface water samples is a first step in our effort to evaluate the water quality, in terms of the presence and environmental/human risk of genotoxicants in the studied lake ecosystems. The present study showed for the first time the presence of genotoxic substances in surface waters of the studied lakes. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. An Archaeological Survey: Shoreline of Lake Darling and Proposed Burlington Dam. Flood Control Project Area, Upper Souris River, North Dakota

    Science.gov (United States)

    1978-01-01

    Sakakawea (Garrison Reservoir) by Haberman and Schneider (1975) and Leaf (1976), surveys in Dunn and Mercer counties (Fox et al. 1976; Lawrence Loendorf...Department of Botony, North Dakota State University, Fargo. Leaf, Gary 1976 Shoreline Survey of Lake Sakakawea : The Badlands in Southern Dunn County, North

  16. 2000 Multibeam Sonar Survey of Crater Lake, Oregon - Data, GIS, Images, and Movies

    Science.gov (United States)

    Gardner, James V.; Dartnell, Peter

    2001-01-01

    In the summer of 2000, the U.S. Geological Survey, Pacific Seafloor Mapping Project in cooperation with the National Park Service, and the Center for Coastal and Ocean Mapping, University of New Hampshire used a state-of-the-art multibeam sonar system to collect high-resolution bathymetry and calibrated, co-registered acoustic backscatter to support both biological and geological research in the Crater Lake area. This interactive CD-ROM contains the multibeam bathymetry and acoustic backscatter data, along with an ESRI ArcExplorer project (and software), images, and movies.

  17. Analysis of growth directions of columnar stromatolites from Walker Lake, western Nevada.

    Science.gov (United States)

    Petryshyn, V A; Corsetti, F A

    2011-09-01

    Samples of digitate, branching, columnar stromatolites were collected from the steep sides and near horizontal top of four in situ boulders located on the southwestern side of Walker Lake, Nevada, to test the widely held assumption that stromatolite column formation represents a phototropic response. We would predict that the columns on the steeply dipping sides of the boulder would bend upwards toward the light during growth if phototropism was significant during stromatolite morphogenesis. Angle of growth measurements on >300 stromatolites demonstrate that the stromatolites grew nearly normal to their growth surface, regardless of the inclination of their growth surface. No significant differences in the distribution of growth angles between north-, south-, east-, or west-facing samples were observed, and stromatolite lamina thickness did not systematically vary with position on the boulder. The lack of a strong phototropic response does not rule out a biological origin for the Walker Lake structures, but it does suggest that phototropic growth was not a dominant factor controlling stromatolite morphogenesis in these stromatolites and that column formation cannot be uniquely attributed as a phototropic response in stromatolites. It is interesting to note that the morphology of the stromatolites on the top of the boulder is identical to stromatolites on the steep sides. Stromatolite morphogenetic models that predict branching typically require a vertically directed sedimentary component, a feature that would have likely affected the stromatolites on the tops of the boulders, but not the sides, suggesting that other factors may be important in stromatolite morphogenesis. © 2011 Blackwell Publishing Ltd.

  18. Links Between Acceleration, Melting, and Supraglacial Lake Drainage of the Western Greenland Ice Sheet

    Science.gov (United States)

    Hoffman, M. J.; Catania, G. A.; Newmann, T. A.; Andrews, L. C.; Rumrill, J. A.

    2012-01-01

    The impact of increasing summer melt on the dynamics and stability of the Greenland Ice Sheet is not fully understood. Mounting evidence suggests seasonal evolution of subglacial drainage mitigates or counteracts the ability of surface runoff to increase basal sliding. Here, we compare subdaily ice velocity and uplift derived from nine Global Positioning System stations in the upper ablation zone in west Greenland to surface melt and supraglacial lake drainage during summer 2007. Starting around day 173, we observe speedups of 6-41% above spring velocity lasting approximately 40 days accompanied by sustained surface uplift at most stations, followed by a late summer slowdown. After initial speedup, we see a spatially uniform velocity response across the ablation zone and strong diurnal velocity variations during periods of melting. Most lake drainages were undetectable in the velocity record, and those that were detected only perturbed velocities for approximately 1 day, suggesting preexisting drainage systems could efficiently drain large volumes of water. The dynamic response to melt forcing appears to 1) be driven by changes in subglacial storage of water that is delivered in diurnal and episodic pulses, and 2) decrease over the course of the summer, presumably as the subglacial drainage system evolves to greater efficiency. The relationship between hydrology and ice dynamics observed is similar to that observed on mountain glaciers, suggesting that seasonally large water pressures under the ice sheet largely compensate for the greater ice thickness considered here. Thus, increases in summer melting may not guarantee faster seasonal ice flow.

  19. Ecology and population status of trout-perch (Percopsis omiscomaycus) in western Lake Erie

    Science.gov (United States)

    Kocovsky, Patrick; Stoneman, Andrea T.; Kraus, Richard T.

    2014-01-01

    Trout-perch Percopsis omiscomaycus is among the most abundant benthic species in Lake Erie, but comparatively little is known about its ecology. Although others have conducted extensive studies on trout-perch ecology, those efforts predated invasions of white perch Morone americana, Dreissena spp., Bythotrephes longimanus and round goby Neogobius melanostomus, suggesting the need to revisit past work. Trout-perch were sampled with bottom trawls at 56 sites during June and September 2010. We examined diets, fecundity, average annual mortality, sex ratio, and long-term population trends at sites sampled since 1961. Trout-perch abundance fluctuated periodically, with distinct shorter- (4-year) and longer-term (over period of 50 years) fluctuations. Males had higher average annual mortality than females. Both sexes were equally abundant at age 0, but females outnumbered males 4:1 by age 2. Diets of trout-perch were dominated by macroinvertebrates, particularly chironomids and Hexagenia sp. Size distributions of trout-perch eggs varied widely and exhibited multiple modes indicative of protracted batch spawning. A review of the few other studies of trout-perch revealed periodic fluctuations in sex ratio of adults, which in light of our evidence of periodicity in abundance suggests the potential for sex-ratio-mediated intrinsic population regulation. Despite the introduction of numerous invasive species in Lake Erie, trout-perch remain one of the most abundant benthic invertivores and the population is relatively stable.

  20. Effect of the permafrost thawing on the organic carbon and microbial activity in thermokarst lakes of Western Siberia: important source of carbon dioxide in the atmosphere

    Science.gov (United States)

    Shirokova, L. S.; Pokrovsky, O. S.; Kirpotin, S. N.; Dupre, B.

    2008-12-01

    Ongoing processes of the permafrost thawing in Western Siberia are likely to increase the surface of water reservoirs via forming so-called thermokarst lakes, mobilizing the organic carbon (OC) from the soil pool to the rivers and, finally, to the ocean, and thus modifying the fluxes of methane and CO2 to the atmosphere. In order to understand the mechanisms of carbon mobilization and biodegradation during permafrost thawing and to establish the link between the OC and microbial activity in forming thermokarstic lakes, we performed a comparative multidisciplinary study on the biogeochemistry of OC and metals in lakes located in the northern part of Western Siberia. About 10 lakes and small ponds of various size and age were sampled for dissolved and colloidal organic carbon and metals and total bacterial cell number. There is a systematic evolution of DOC, pH, trace elements and biological activity during successions of thermokarst lakes encountered in the present study. At the beginning of permafrost thawing at the scale of several meter size ponds, fast lixiviation of unaltered peat yields significant amount of OC, major and trace elements; the pH of these waters is between 3.5 and 4.0 and the conductivity is 20-30 μS. The intermediate stage of lake formation still preserve low pHs, high DOC and conductivity, even in relatively large, up to 1 km diameter but fast growing lakes. At these stages, there is no any productivity as phytoplankton cannot live in these acidic waters and bacterial mineralization intensity is around 0.3 mg C/L/day both in the surface and bottom horizons. Once the lake border is stabilized, there are no new "unaltered peat" sources and the biological processes start to consume the OC and nutrients. At this stage, there is still no production in the water column (high, up to 0.3 mg C/L/day. At this final stage, the remaining part of the lake located in the centre of the "khasyrei" exhibits the highest pH (5.5-6.0), presence of green algae

  1. Behavioural responses of western gray whales to a 4-D seismic survey off northeastern Sakhalin Island, Russia

    OpenAIRE

    Gailey, Glenn; Sychenko, Olga; McDonald, Trent; Racca, Roberto; Rutenko, Alexander; Bröker, Koen

    2016-01-01

    A seismic survey was conducted off the northeastern coast of Sakhalin Island, Russia in 2010. The survey area was adjacent to the only known near-shore feeding ground of the Critically Endangered population of western gray whales Eschrichtius robustus in the western Pacific south of the Aleutian Islands. This study examined the effectiveness of efforts to minimize the behavioural responses of the whales to vessel proximity and sound during the survey. Two shore-based behavioural observation t...

  2. Survey of selenium in water, zooplankton and fish in Lake Koocanusa, British Columbia, 2008

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, L. [Spirogyra Scientific Consulting, Cranbrook, BC (Canada)

    2009-07-15

    Coal mining within the Elk River basin has resulted in elevated levels of water-borne selenium. The purpose of this study was to determine concentrations of metals, specifically selenium, in 3 specific ecosystem compartments, notably water, zooplankton and fish tissue, within Lake Koocanusa, upstream and downstream of the Elk River confluence. The study was designed to determine the risks to the aquatic environment, based on a comparison with current aquatic life water quality guidelines and tissue-based thresholds. The study also determined whether the data corroborates historical data for Lake Koocanusa. The changes in concentrations among the sites were measured. Five sub-samples of water and zooplankton were sampled at each of 3 locations along the reservoir, and 2 species of fish (kokanee and peamouth chub), were also sampled at similar locations. Egg and muscle tissue were analyzed, as well as whole body tissue in order to compare data with the 2002 survey. This paper outlined the methods used and results of the study. Results and recommendations were also presented. The author recommended that a survey similar to this one be conducted in 2011 in order to evaluate trends in the downstream lentic environment, but with consideration for several additions and modifications. 32 refs., 5 tabs., 12 figs., 13 appendices.

  3. Bathymetric and geophysical surveys of Englebright Lake, Yuba-Nevada Counties, California

    Science.gov (United States)

    Childs, Jonathan R.; Snyder, Noah P.; Hampton, Margaret A.

    2003-01-01

    Harry L. Englebright Lake is a 9-mile-long (14-kilometer) reservoir located in the Sierra Nevada foothills of northern California on the Yuba River gorge known as The Narrows. The reservoir is impounded by Englebright Dam (Photo 1), a concrete arch structure spanning 348 meters (1,142 feet) across and 79 meters (260 feet) high. The dam was constructed in 1941 for the primary purpose of trapping sediment derived from anticipated hydraulic mining operations in the Yuba River watershed. Hydraulic mining in the Sierra Nevada was halted in 1884 but resumed on a limited basis until the 1930's under the regulation of the California Debris Commission. Although no hydraulic mining in the upper Yuba River watershed resumed after the construction of the dam, the historical mine sites continued to contribute sediment to the river. Today, Englebright Lake is used primarily for recreation and hydropower. In 2001 and 2002, the U.S. Geological Survey (USGS) conducted bathymetric, geophysical, and geological studies of the reservoir under the auspices of the Upper Yuba River Studies Program (UYRSP), a multi-disciplinary investigation into the feasibility of introducing anadromous fish species to the Yuba River system upstream of Englebright Dam. A primary purpose of these studies was to assess the quantity and nature of the sediment that has accumulated behind the dam over the past 60 years. This report presents the results of those surveys, including a new bathymetric map of the reservoir and estimates of the total accumulated sediment volume.

  4. Densities of Hexagenia mayfly nymphs in western Lake Erie, 1999-2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Densities of Hexagenia spp. mayfly nymphs by age class are presented from 1999 through 2014. This range is significant in that it includes the year of peak abundance...

  5. Geohydrology, water quality, and water budgets of Golden Gate Park and the Lake Merced area in the western part of San Francisco, California

    Science.gov (United States)

    Yates, E.B.; Hamlin, S.N.; McCann, L.H.

    1990-01-01

    The groundwater resources in the western part of the San Francisco, groundwater budgets for Golden Gate Park and the Lake Merced area, and a surface-water budget for Lake Merced are described. A continuous groundwater basin underlies a 39-sq-mi coastal strip in the San Francisco Peninsula south of the city. Basin fill consists largely of sand and silt. An extensive subsurface clay layer is present near Lake Merced. Recharge is principally from rainfall and irrigation-return flow, with lesser amounts from leaking water and sewer pipes, which were identified in part by stable-isotope and major ion analyses. In Golden Gate Park, about 1, 070 acre-ft/yr of groundwater flows to the ocean. Water levels are not declining, and pumpage could be safely increased. However, nitrate concentrations in excess of Federal drinking-water standards in water from many wells may limit potential uses of groundwater. Groundwater in the Lake Merced area is in a state of overdraft, as indicated by long- term declines in the level of Lake Merced and by groundwater levels persistently below sea level in deep wells. Seawater intrusion has not been detected, however. A surface-water budget for Lake Merced indicates that the largest inflow is from shallow groundwater and the largest outflow is loss by evaporation. (USGS)

  6. Fossil pigments as indicators of phototrophic response to salinity and climatic change in lakes of Western Canada

    Energy Technology Data Exchange (ETDEWEB)

    Vinebrooke, R. D.; Hall, R. I.; Leavitt, R. [Regina Univ., SK (Canada). Dept. of Biology; Cumming, B. F. [Queen`s Univ., Kingston, ON (Canada). Paleoecological Environmental Assessment and Research Lab

    1998-03-01

    Changes in fossil pigments among 111 saline lakes in British Columbia were quantified and past changes in phototrophic communities in three closed-basin prairie lakes (Antelope Lake, Kenosee Lake and Clearwater Lake) were reconstructed. Using redundancy analysis, it was found that pigment concentrations were greatest in deep stratified lakes but were unaffected by ion concentrations, pH or conductivity. Algal standing crop was correlated only with fossil measures of total algal abundance, however, relative abundance of fossil carotenoids varied with lake chemistry. Increase in salinity caused fucoxanthin to be replaced by lutein-zeaxanthin and diatoxanthin, while alloxanthin and myxoxanthophyll were most commonly found in lakes with low calcium and high dissolved organic carbon content. Post-depositional degradation did not appear to alter the relation between pigment abundance and environmental characteristics. Considered as a whole, these results suggest that in saline lakes, fossil pigments are paleoecological proxies for phototrophic community change. 43 refs., 8 figs.

  7. Cholera outbreak caused by drinking lake water contaminated with human faeces in Kaiso Village, Hoima District, Western Uganda, October 2015.

    Science.gov (United States)

    Oguttu, David W; Okullo, A; Bwire, G; Nsubuga, P; Ario, A R

    2017-10-10

    On 12 October 2015, a cholera outbreak involving 65 cases and two deaths was reported in a fishing village in Hoima District, Western Uganda. Despite initial response by the local health department, the outbreak persisted. We conducted an investigation to identify the source and mode of transmission, and recommend evidence-led interventions to control and prevent cholera outbreaks in this area. We defined a suspected case as the onset of acute watery diarrhoea from 1 October to 2 November 2015 in a resident of Kaiso Village. A confirmed case was a suspected case who had Vibrio cholerae isolated from stool. We found cases by record review and active community case finding. We performed descriptive epidemiologic analysis for hypothesis generation. In an unmatched case-control study, we compared exposure histories of 61 cases and 126 controls randomly selected among asymptomatic village residents. We also conducted an environmental assessment and obtained meteorological data from a weather station. We identified 122 suspected cases, of which six were culture-confirmed, 47 were confirmed positive with a rapid diagnostic test and two died. The two deceased cases had onset of the disease on 2 October and 10 October, respectively. Heavy rainfall occurred on 7-11 October; a point-source outbreak occurred on 12-15 October, followed by continuous community transmission for two weeks. Village residents usually collected drinking water from three lakeshore points - A, B and C: 9.8% (6/61) of case-persons and 31% (39/126) of control-persons were found to usually use point A, 21% (13/61) of case-persons and 37% (46/126) of control-persons were found to usually use point B (OR = 1.8, 95% CI: 0.64-5.3), and 69% (42/61) of case-persons and 33% (41/126) of control-persons were found to usually use point C (OR = 6.7; 95% CI: 2.5-17) for water collection. All case-persons (61/61) and 93% (117/126) of control-persons reportedly never treated/boiled drinking water (OR

  8. A survey of oil and gas leases for most of the western states

    Energy Technology Data Exchange (ETDEWEB)

    Shofner, P.G. (State Land Commission, Oklahoma City, OK (United States))

    1992-12-01

    A survey on 13 of the western states is presented. These states have been surveyed on the new trends in marketing and managing the income from minerals. The survey covers 13 states with approximately 81 million acres of land in the western part of the US. The annual income from oil and gas production on these land is over two billion dollars, which is placed in permanent trusts. That permanent trust in the State of Texas is about eight billion dollars. The State of Oklahoma has approximately three-quarters of a billion dollars in a permanent trust. The interest off the income on these trust funds is distributed to education annually. The Oklahoma School Land Commission provides about 80 million dollars a year for the support of schools. As state revenues have dropped, the Land Commissions in the various states are looked at to provide additional income to offset the increasing cost of education. Almost every state at this time is having some sort of problem providing proper financial support for educational institutions. The survey was compiled to try to come up with new ideas to increase income, therefore, providing greater income for schools and hopefully offsetting some of the loss in the state revenues.

  9. Soil erosion risk assessment using interviews, empirical soil erosion modeling (RUSLE) and fallout radionuclides in a volcanic crater lake watershed subjected to land use change, western Uganda

    Science.gov (United States)

    De Crop, Wannes; Ryken, Nick; Tomma Okuonzia, Judith; Van Ranst, Eric; Baert, Geert; Boeckx, Pascal; Verschuren, Dirk; Verdoodt, Ann

    2017-04-01

    Population pressure results in conversion of natural vegetation to cropland within the western Ugandan crater lake watersheds. These watersheds however are particularly prone to soil degradation and erosion because of the high rainfall intensity and steep topography. Increased soil erosion losses expose the aquatic ecosystems to excessive nutrient loading. In this study, the Katinda crater lake watershed, which is already heavily impacted by agricultural land use, was selected for an explorative study on its (top)soil characteristics - given the general lack of data on soils within these watersheds - as well as an assessment of soil erosion risks. Using group discussions and structured interviews, the local land users' perceptions on land use, soil quality, soil erosion and lake ecology were compiled. Datasets on rainfall, topsoil characteristics, slope gradient and length, and land use were collected. Subsequently a RUSLE erosion model was run. Results from this empirical erosion modeling approach were validated against soil erosion estimates based on 137Cs measurements.

  10. First, Second and Third Habsburg Military Surveys: documents of the transition of Lake Balaton from natural to artificial hydrologic regime

    Science.gov (United States)

    Zlinszky, András.

    2010-05-01

    The hydrology of Lake Balaton, the largest lake in Central Europe has a long history of human impact, which probably started in prehistoric times through agricultural expansion. The most important change in the water regime of the Lake is considered to be the opening of the Sió Canal in 1863. This resulted in the lowering of the average water level by more than a meter and is known to have had a strong effect on the immediate shore zone of the lake and on the adjoined wetland areas. However, since the sluice and canal could only drain a restricted amount of water, these widespread effects were probably also caused by other changes on the watershed of the lake. The First Military Survey of the Habsburg Empire was measured nearly 100 years before the opening of the canal and is the first detailed survey of this area, and it can be considered as a benchmark of the situation before major human-induced changes on the catchment of the lake. The sheets of the Second Military Survey were mapped in an interval of 6-11 years before the drainage, so they show the situation with major anthropogenic impacts on the wetlands and the drainage basin but with the canal still not opened. The Third Military Survey shows the situation with major anthropogenic changes on the catchment and also the effect of the canal opening. Water level measurement data exists continuously since the Canal was opened but not before that time. The First Military Survey has no geodetic projection, so a seamless georeferenced mosaic of the Lake Balaton catchment had to be created by constrained polynomial georeferencing. The Second and Third Military Surveys were mapped using a projected coordinate system so these could be simply reprojected into a GIS. The second military survey has a unified map legend system and visual interpretation of these maps is easy, but most of the Third military survey only survived in form of black-and-white copies and these are more difficult to read. The elevations of the

  11. Using geophysics on a terminal moraine damming a glacial lake: the Flatbre debris flow case, Western Norway

    Directory of Open Access Journals (Sweden)

    I. Lecomte

    2008-04-01

    Full Text Available A debris flow occurred on 8 May 2004, in Fjǽrland, Western Norway, due to a Glacial Lake Outburst Flood and a natural terminal moraine failure. The site was investigated in 2004 and 2005, using pre- and post-flow aerial photos, airborne laser scanning, and extensive field work investigations, resulting in a good understanding of the mechanics of the debris flow, with quantification of the entrainment and determination of the final volume involved. However, though the moraine had a clear weak point, with lower elevation and erosion due to overflowing in the melting season, the sudden rupture of the moraine still needs to be explained. As moraines often contain an ice core, a possible cause could be the melting of the ice, inducing a progressive weakening of the structure. Geophysical investigations were therefore carried out in September 2006, including seismic refraction, GPR and resistivity. All methods worked well, but none revealed the presence of ice, though the depth to bedrock was determined. On the contrary, the moraine appeared to be highly saturated in water, especially in one area, away from the actual breach and corresponding to observed water seepage at the foot of the moraine. To estimate future hazard, water circulation through the moraine should be monitored over time.

  12. A bioenergetics modeling evaluation of top-down control of ruffe in the St. Louis River, western Lake Superior

    Science.gov (United States)

    Mayo, Kathleen R.; Selgeby, James H.; McDonald, Michael E.

    1998-01-01

    Ruffe (Gymnocephalus cernuus), were accidentally introduced into the St. Louis River estuary, western Lake Superior, in the mid 1980s and it was feared that they might affect native fish through predation on eggs and competition for forage and habitat. In an effort to control the abundance of ruffe and limit dispersal, a top-down control strategy using predators was implemented in 1989. We used bioenergetics modeling to examine the efficacy of top-down control in the St. Louis River from 1991 to 1994. Five predators--northern pike (Esox lucius), walleye (Stizostedion vitreum vitreum), smallmouth bass (Micropterus dolomieui), brown bullhead (Ictalurus nebulosus), and yellow perch (Perca flavescens)--were modeled to determine their consumption of ruffe and four other native prey species-spottail shiner (Notropis hudsonius), emerald shiner (Notropis atherinoides), yellow perch (Perca flavescens), and black crappie (Pomoxis nigromaculatus). Although predators ate as much as 47% of the ruffe biomass in 1 year, they were not able to halt the increase in ruffe abundance. The St. Louis River is an open system that allows predators to move freely out of the system, and the biomass of managed predators did not increase. A selectivity index showed all five predators selected the native prey and avoided ruffe. The St. Louis River has several predator and prey species creating many complex predator-prey interactions; and top-down control of ruffe by the predators examined in this study did not occur.

  13. AFSC/ABL: Deep-Water Longline Survey for Giant Grenadier and Sablefish in the Western Gulf of Alaska

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — An experimental bottom longline survey was conducted at depths >1,000 m in the western Gulf of Alaska in August 2008. The objective was to investigate the...

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

    Science.gov (United States)

    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

  15. A Four Lake Latitudinal Comparison Along Coastal Southern to Central California: A Late-Holocene Perspective on the Western US Precipitation Dipole.

    Science.gov (United States)

    Kirby, M.; Nichols, K. E.; Ramezan, R.; Palermo, J. A.; Hiner, C.; Bonuso, N.; Patterson, W. P.; Silveira, E.

    2016-12-01

    One of the dominant hydroclimatic features of the western United States is the winter season precipitation dipole. The dipole is characterized by a N-S antiphased precipitation regime presently centered on 40° N latitude (Cayan et al., 1998; Dettinger et al., 1998; Wise, 2010). For example, the position of the dipole dictates where CA receives its winter precipitation; thus, it is critical to understand the dipole from a paleoperspective, which at present is poorly known. Here, we present four lake sites spanning 33°-36° N latitude along coastal CA. These sites include: Lake Elsinore, Crystal Lake, Zaca Lake, and Abbott Lake. All four of these sites are located south of the dipole's average historic (since 1950 AD) latitude. The predominant hydroclimatic indicator is similar for each basin (i.e., grain size); although, several other indicators are used for independent verification/assessment of the grain size interpretation. Notably, these lakes contain varied age control, which limits site-to-site correlation without consideration of age model dependence. Following a Bayesian framework, MCMC algorithms in conjuction with radiocarbon dating will be used to estimate timestamps of sediment deposits with a degree of statistical uncertainty. Samples from the posterior distribution will be used to correlate hydroclimatic features between sites. Included in this analysis are tree ring records from the region to assess the similarities and differences as recorded in annually resolved tree ring drought reconstructions and decadally resolved lake sediment hydroclimatic records. Finally, the four sites are assessed in the context of tropical and north Pacific SST forcing.

  16. Community seroprevalence survey for yaws and trachoma in the Western Division of Fiji.

    Science.gov (United States)

    Cocks, Naomi; Rainima-Qaniuci, Merelesita; Yalen, Chelsea; Macleod, Colin; Nakolinivalu, Apisalome; Migchelsen, Stephanie; Roberts, Chrissy H; Butcher, Robert; Kama, Mike; Mabey, David; Marks, Michael

    2016-12-01

    Both yaws and trachoma are endemic in several countries in the Pacific. In co-endemic countries there may be potential synergies between both control programmes. We undertook a cluster randomised trachoma and yaws seroprevalence survey of children in the Western Division of Fiji. Children were examined for skin lesions consistent with active yaws. A dried blood spot was collected which was tested using the Treponema pallidum particle agglutination (TPPA) test and an ELISA to detect antibodies against Pgp3. A total of 607 children from 305 households across 23 villages were recruited into the survey. On skin examination, no child had clinical evidence of yaws, and the TPPA assay was negative in all children (0%, 95% CI 0.0-0.6). The seroprevalence of Pgp3 antibodies was 20.9% (95% CI 17.8-24.6%). In this study there was neither clinical nor serological evidence that transmission of yaws was ongoing. The Pgp3 seroprevalence pattern was consistent with either low level transmission of ocular Chlamydia trachomatis or exposure to C. trachomatis in the birth canal which is consistent with a survey conducted in the same region in 2013. These data suggest neither yaws nor ocular chlamydia infection are a significant public health problem in the Western Division of Fiji. © The Author 2016. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene.

  17. Western Australia facing critical losses in its midwifery workforce: a survey of midwives' intentions.

    Science.gov (United States)

    Pugh, Judith D; Twigg, Diane E; Martin, Tracy L; Rai, Tapan

    2013-05-01

    the ongoing attrition of the midwifery workforce frustrates future workforce planning and the provision of maternity services in Western Australia. This project determined factors contributing to the intention of the midwives to move jobs and/or leave the profession. a cross-sectional survey approach was taken for this descriptive research utilising a self-administered questionnaire developed by the Nursing and Midwifery Office, Department of Health, Western Australia. public and private health sectors in Western Australia, April-May 2010. 1,600 midwives employed in the public and private health sectors throughout Western Australia were invited to participate: 712 responded (44.5%), one-fifth of the state's registered midwives. most midwives worked part-time in a clinical role in public hospitals. Almost half intended moving jobs within 5 years and/or leaving midwifery. Excluding midwives of retirement age, the most common reasons for intending to move jobs were family commitments, working conditions and role dissatisfaction. Those intending to leave midwifery cited work-life balance, career change and family commitments. Midwives thought addressing the following issues would improve midwifery retention: flexible work arrangements, remuneration, staffing and caseload, workplace culture, professional development and models of care. retaining the midwifery workforce requires attention to workforce practices particularly flexible work arrangements and workloads; models of care to strengthen midwives' relationships with clients and colleagues; and accessible professional development. a review of workplace practices at unit and institution levels is urgently required in Western Australia so that midwives can achieve work-life balance and practice to the full extent of their professional role. These changes are necessary to forestall premature retirement of skilled and experienced midwives from the profession and workforce churn. Crown Copyright © 2012. Published by

  18. Vegetation Survey of the Banks Lake National Wildlife Refuge, Lanier County, Georgia

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report documents a vascular plant inventory performed for Banks Lake NWR from 2009 through 2011. Banks Lake National Wildlife Refuge (NWR) comprises 3,559 acre...

  19. Survey of Internship Education in Western Countries and the Problems to be Considered in Japan

    Science.gov (United States)

    Noguchi, Toru; Yoshikawa, Kozo; Kaneko, Katsuhiko

    To survey the states of internship education in western countries, the authors visited seven universities, three companies and an institute in North America and Europe. The survey showed that internship of one semester (2-3 months) or more is quite common in these countries. In the graduate courses, joining some research/development projects out of the school, including overseas, is strongly recommended. Accepting internship students gives benefits also to the host companies/institutions by carrying short term projects as well as attracting talented students as expected employees. To promote such internship system in Japan, it is necessary to make education programs concordant with such long term internships. Marked improvement in practical abilities of students will also be reflected to research activities and will result in the benefit of the universities. Promotion of internship here is also necessary from the global aspect, to attract good overseas students.

  20. A test of the Lake Habitat Survey method in Cleveland Reservoir ...

    African Journals Online (AJOL)

    2016-01-01

    Jan 1, 2016 ... and Lake Habitat Modification Score (LHMS) were used to assess the habitat quality and the magnitude of human impact on the reservoirs. Cleveland ... catchment impacts on lakes and reservoirs in LHS scoring metrics. Keywords: Lake Habitat ...... SYSTAT Software, Inc., Chicago. TENDAUPENYU P ...

  1. Archaeological Survey and Testing for the Upstream Work. Big Stone Lake-Whetstone River Project Area,

    Science.gov (United States)

    1975-09-01

    Hubbard County Crookston Site, Polk County Grand Portage, Lake County Archaeological Field Research (continued) Orwell Site, Ottertail County Lake... George I. Quimby. 1960. Minnesota History, Vol. No. . p. 174. 1961 Review: Indian Life in the Upper Great Lakes, 11,000 B.C. to A.D. 1800 by George I

  2. Large-scale Watershed Modeling: NHDPlus Resolution with Achievable Conservation Scenarios in the Western Lake Erie Basin

    Science.gov (United States)

    Yen, H.; White, M. J.; Arnold, J. G.; Keitzer, S. C.; Johnson, M. V. V.; Atwood, J. D.; Daggupati, P.; Herbert, M. E.; Sowa, S. P.; Ludsin, S.; Robertson, D. M.; Srinivasan, R.; Rewa, C. A.

    2016-12-01

    By the substantial improvement of computer technology, large-scale watershed modeling has become practically feasible in conducting detailed investigations of hydrologic, sediment, and nutrient processes. In the Western Lake Erie Basin (WLEB), water quality issues caused by anthropogenic activities are not just interesting research subjects but, have implications related to human health and welfare, as well as ecological integrity, resistance, and resilience. In this study, the Soil and Water Assessment Tool (SWAT) and the finest resolution stream network, NHDPlus, were implemented on the WLEB to examine the interactions between achievable conservation scenarios with corresponding additional projected costs. During the calibration/validation processes, both hard (temporal) and soft (non-temporal) data were used to ensure the modeling outputs are coherent with actual watershed behavior. The results showed that widespread adoption of conservation practices intended to provide erosion control could deliver average reductions of sediment and nutrients without additional nutrient management changes. On the other hand, responses of nitrate (NO3) and dissolved inorganic phosphorus (DIP) dynamics may be different than responses of total nitrogen and total phosphorus dynamics under the same conservation practice. Model results also implied that fewer financial resources are required to achieve conservation goals if the goal is to achieve reductions in targeted watershed outputs (ex. NO3 or DIP) rather than aggregated outputs (ex. total nitrogen or total phosphorus). In addition, it was found that the model's capacity to simulate seasonal effects and responses to changing conservation adoption on a seasonal basis could provide a useful index to help alleviate additional cost through temporal targeting of conservation practices. Scientists, engineers, and stakeholders can take advantage of the work performed in this study as essential information while conducting policy

  3. Effects of implementing organic rice-duck integrated farming on reducing agricultural diffuse pollution around Dianshan Lake in the western suburbs of Shanghai

    Science.gov (United States)

    Hu, Xue-Feng; Teng, Qing

    2017-04-01

    Located in the western suburbs of Shanghai, Dianshan Lake is a major source of Huangpu River, a mother river flowing through the metropolitan area. To protect the drinking water source areas, the development of any industries and livestock breeding is forbidden around the lake since the early time. However, the lake is still under a eutrophic state throughout the year. In 2013, for example, total N and total P in the lake water were 2.98 mg L-1 and 0.17 mg L-1 on average, respectively. It is believed that 72.2% of N and 73.1% of P in the lake come from agricultural diffuse pollution. The areas surrounding the lake include six towns and are all low-lying in landform. There are 5975 ha paddy fields at the six towns, making up 33.1% of total farming land in the areas. According to our questionnaires to local farmers at Jinze Town, one of the six towns, for the consecutive five years, the amounts of N and P2O5 applied within the rice growing season under the conventional rice farming are 336.6 kg ha-1 and 76.9 kg ha-1 on average, respectively, and those lost through leaching and runoff are 15.42 kg ha-1 and 3.55 kg ha-1 on average, respectively. Further study estimated that the total amounts of N and P2O5 applied around the lake within the rice growing season are 2.01×106 kg year-1 and 4.59×105 kg year-1, respectively; those lost through leaching and runoff are 0.99×105 kg year-1 and 0.23×105 kg year-1, respectively; those discharged from the fields into the lake are 0.99×104 kg year-1 and 0.23×104 kg year-1, respectively. Our study also indicated that the amount of pesticides and herbicides discharged from the paddy fields at the six towns into the lake is approximately 1.67×104 kg year-1. Appreciately, the agricultural diffuse pollution from the paddy fields surrounding the lake have posed severe threat to the lake. The field experiments indicated that raising ducks in the paddy fields within the rice growing season can not only highly reduce weed hazards and

  4. Benthos and plankton community data for selected rivers and harbors along the western Lake Michigan shoreline, 2014

    Science.gov (United States)

    Scudder Eikenberry, Barbara C.; Burns, Daniel J.; Olds, Hayley T.; Bell, Amanda H.; Mapel, Kassidy T.

    2016-06-15

    Benthos (benthic invertebrates) and plankton (zooplankton and phytoplankton) communities were sampled in 2014 at 10 Wisconsin rivers and harbors, including 4 sites in Great Lakes Areas of Concern and 6 less degraded comparison sites with similar physical and chemical characteristics, including climate, latitude, geology, and land use. Previous U.S. Geological Survey sampling was completed in 2012, but because of ongoing sediment remediation at three of the Areas of Concern (AOCs) and unusually hot and dry conditions in many areas during 2012, additional sampling was added in 2014. Comparable sampling methods were used in 2012 and 2014. Benthos were collected by using Hester-Dendy artificial substrate samplers and composite Ponar grab samples of bottom sediment; zooplankton were collected by using tows from depth to the surface with a 63-micrometer mesh plankton net; phytoplankton were collected by using whole water samples composited from set depth intervals. This report describes the study areas and field sampling methods for 2014, and it presents data on taxonomic identification and abundance of benthos and plankton that can serve as a basis for evaluation of related Beneficial Use Impairments (BUIs) at the AOCs. Physical and chemical data were sampled concurrently (specific conductance, temperature, pH, dissolved oxygen, chlorophyll a, total and volatile suspended solids in water samples; particle size and volatile-on-ignition of sediment in benthic grab samples). The results of field quality assurance-quality control are also presented.

  5. Survey of duckweed diversity in Lake Chao and total fatty acid, triacylglycerol, profiles of representative strains.

    Science.gov (United States)

    Tang, J; Li, Y; Ma, J; Cheng, J J

    2015-09-01

    Lemnaceae (duckweeds) are widely distributed aquatic flowering plants. Their high growth rate, starch content and suitability for bioremediation make them potential feedstock for biofuels. However, few natural duckweed resources have been investigated in China, and there is no information about total fatty acid (TFA) and triacylglycerol (TAG) composition of duckweeds from China. Here, the genetic diversity of a natural duckweed population collected from Lake Chao, China, was investigated using multilocus sequence typing (MLST). The 54 strains were categorised into four species in four genera, representing 12 distinct sequence types. Strains representing Lemna aequinoctialis and Spirodela polyrhiza were predominant. Interestingly, a surprisingly high degree of genetic diversification within L. aequinoctialis was observed. The four duckweed species revealed a uniform fatty acid composition, with three fatty acids, palmitic acid, linoleic acid and linolenic acid, accounting for more than 80% of the TFA. The TFA in biomass varied among species, ranging from 1.05% (of dry weight, DW) for L. punctata and S. polyrhiza to 1.62% for Wolffia globosa. The four duckweed species contained similar TAG contents, 0.02% mg · DW(-1). The fatty acid profiles of TAG were different from those of TFA, and also varied among the four species. The survey investigated the genetic diversity of duckweeds from Lake Chao, and provides an initial insight into TFA and TAG of four duckweed species, indicating that intraspecific and interspecific variations exist in the content and composition of both TFA and TAG in comparison with other studies. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

  6. Cholera epidemics, war and disasters around Goma and Lake Kivu: an eight-year survey.

    Science.gov (United States)

    Bompangue, Didier; Giraudoux, Patrick; Piarroux, Martine; Mutombo, Guy; Shamavu, Rick; Sudre, Bertrand; Mutombo, Annie; Mondonge, Vital; Piarroux, Renaud

    2009-01-01

    During the last eight years, North and South Kivu, located in a lake area in Eastern Democratic Republic of Congo, have been the site of a major volcano eruption and of numerous complex emergencies with population displacements. These conditions have been suspected to favour emergence and spread of cholera epidemics. In order to assess the influence of these conditions on outbreaks, reports of cholera cases were collected weekly from each health district of North Kivu (4,667,699 inhabitants) and South Kivu (4,670,121 inhabitants) from 2000 through 2007. A geographic information system was established, and in each health district, the relationships between environmental variables and the number of cholera cases were assessed using regression techniques and time series analysis. We further checked for a link between complex emergencies and cholera outbreaks. Finally, we analysed data collected during an epidemiological survey that was implemented in Goma after Nyiragongo eruption. A total of 73,605 cases and 1,612 deaths of cholera were reported. Time series decomposition showed a greater number of cases during the rainy season in South Kivu but not in North Kivu. Spatial distribution of cholera cases exhibited a higher number of cases in health districts bordering lakes (Odds Ratio 7.0, Confidence Interval range 3.8-12.9). Four epidemic reactivations were observed in the 12-week periods following war events, but simulations indicate that the number of reactivations was not larger than that expected during any random selection of period with no war. Nyiragongo volcanic eruption was followed by a marked decrease of cholera incidence. Our study points out the crucial role of some towns located in lakeside areas in the persistence of cholera in Kivu. Even if complex emergencies were not systematically followed by cholera epidemics, some of them enabled cholera spreading.

  7. Cholera epidemics, war and disasters around Goma and Lake Kivu: an eight-year survey.

    Directory of Open Access Journals (Sweden)

    Didier Bompangue

    Full Text Available BACKGROUND: During the last eight years, North and South Kivu, located in a lake area in Eastern Democratic Republic of Congo, have been the site of a major volcano eruption and of numerous complex emergencies with population displacements. These conditions have been suspected to favour emergence and spread of cholera epidemics. METHODOLOGY/PRINCIPAL FINDINGS: In order to assess the influence of these conditions on outbreaks, reports of cholera cases were collected weekly from each health district of North Kivu (4,667,699 inhabitants and South Kivu (4,670,121 inhabitants from 2000 through 2007. A geographic information system was established, and in each health district, the relationships between environmental variables and the number of cholera cases were assessed using regression techniques and time series analysis. We further checked for a link between complex emergencies and cholera outbreaks. Finally, we analysed data collected during an epidemiological survey that was implemented in Goma after Nyiragongo eruption. A total of 73,605 cases and 1,612 deaths of cholera were reported. Time series decomposition showed a greater number of cases during the rainy season in South Kivu but not in North Kivu. Spatial distribution of cholera cases exhibited a higher number of cases in health districts bordering lakes (Odds Ratio 7.0, Confidence Interval range 3.8-12.9. Four epidemic reactivations were observed in the 12-week periods following war events, but simulations indicate that the number of reactivations was not larger than that expected during any random selection of period with no war. Nyiragongo volcanic eruption was followed by a marked decrease of cholera incidence. CONCLUSION/SIGNIFICANCE: Our study points out the crucial role of some towns located in lakeside areas in the persistence of cholera in Kivu. Even if complex emergencies were not systematically followed by cholera epidemics, some of them enabled cholera spreading.

  8. Long-term trends in habitat use of offshore demersal fishes in western Lake Huron suggest large-scale ecosystem change

    Science.gov (United States)

    Riley, Stephen C.; Adams, Jean V.

    2010-01-01

    We estimated mean depths of capture for offshore demersal fish species, grouped into three habitat-based guilds (shallow benthic, pelagic, and deep benthic), using fall bottom trawl data (27–73 m) in the western main basin of Lake Huron from 1976 to 2007. The mean depth of capture of the shallow and deep benthic guilds initially exhibited a trend toward capture in shallower water, switched to a trend toward capture in deeper water in 1991, and changed back to a trend toward capture in shallower water in 2001–2002. Species in the pelagic guild showed a similar pattern, but the initial change point occurred in 1981 for this guild. Individual species in these guilds showed variable patterns of depth distribution, but a feature common to all guilds and all pelagic and deep benthic species was a change to a trend toward capturing fish in shallower water that occurred nearly simultaneously (1999–2002). These common trends suggest that large-scale factors are affecting the habitat use of offshore demersal fish species in Lake Huron. The depth distributions of the three guilds have converged in recent years, indicating that the locations of suitable habitat for offshore demersal fishes may be changing. Our results indicate that the benthic ecology of the western main basin of Lake Huron is undergoing profound changes across a large spatial scale that are affecting the habitat use of offshore demersal fishes. We suggest that these changes are related to recent invasions of exotic species.

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

    Science.gov (United States)

    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.

  10. Distributions of branched GDGTs in soils and lake sediments from western Uganda: Implications for a lacustrine paleothermometer

    NARCIS (Netherlands)

    Loomis, S.E.; Russell, J.M.; Sinninghe Damsté, J.S.

    2011-01-01

    Bacterially produced branched glycerol dialkyl glycerol tetraethers (GDGTs) are ubiquitous in soils and lake sediments and can potentially be used to reconstruct past temperatures. In lakes, however, it is still unclear if these compounds are derived from eroded soils or if they are produced in

  11. In-situ multispectral and bathymetric measurements over a supraglacial lake in western Greenland using a remotely controlled watercraft

    Science.gov (United States)

    Tedesco, M.; Steiner, N.

    2011-05-01

    Supraglacial lakes form from meltwater on the Greenland ice sheet in topographic depressions on the surface, affecting both surface and sub-glacial processes. As the reflectance in the visible and near-infrared regions of a column of water is modulated by its height, retrieval techniques using spaceborne remote sensing data (e.g. Landsat, MODIS) have been proposed in the literature for the detection of lakes and estimation of their volume. These techniques require basic assumptions on the spectral properties of the water as well as the bottom of the lake, among other things. In this study, we report results obtained from the analysis of concurrent in-situ multi-spectral and depth measurements collected over a supraglacial lake during early July 2010 in West Greenland (Lake Olivia, 69°36'35" N, 49°29'40" W) and aim to assess some of the underlying hypotheses in remote sensing based bathymetric approaches. In particular, we focus our attention on the analysis of the lake bottom albedo and of the water attenuation coefficient. The analysis of in-situ data (collected by means of a remotely controlled boat equipped with a GPS, a sonar and a spectrometer) highlights the exponential trend of the water-leaving reflectance with lake depth. The values of the attenuation factor obtained from in-situ data are compared with those computed using approaches proposed in the literature. Also, the values of the lake bottom albedo from in-situ measurements are compared with those obtained from the analysis of reflectance of shallow waters. Finally, we quantify the error between in-situ measured and satellite-estimated lake depth values for the lake under study.

  12. In-situ multispectral and bathymetric measurements over a supraglacial lake in western Greenland using a remotely controlled watercraft

    Directory of Open Access Journals (Sweden)

    M. Tedesco

    2011-05-01

    Full Text Available Supraglacial lakes form from meltwater on the Greenland ice sheet in topographic depressions on the surface, affecting both surface and sub-glacial processes. As the reflectance in the visible and near-infrared regions of a column of water is modulated by its height, retrieval techniques using spaceborne remote sensing data (e.g. Landsat, MODIS have been proposed in the literature for the detection of lakes and estimation of their volume. These techniques require basic assumptions on the spectral properties of the water as well as the bottom of the lake, among other things. In this study, we report results obtained from the analysis of concurrent in-situ multi-spectral and depth measurements collected over a supraglacial lake during early July 2010 in West Greenland (Lake Olivia, 69°36'35" N, 49°29'40" W and aim to assess some of the underlying hypotheses in remote sensing based bathymetric approaches. In particular, we focus our attention on the analysis of the lake bottom albedo and of the water attenuation coefficient. The analysis of in-situ data (collected by means of a remotely controlled boat equipped with a GPS, a sonar and a spectrometer highlights the exponential trend of the water-leaving reflectance with lake depth. The values of the attenuation factor obtained from in-situ data are compared with those computed using approaches proposed in the literature. Also, the values of the lake bottom albedo from in-situ measurements are compared with those obtained from the analysis of reflectance of shallow waters. Finally, we quantify the error between in-situ measured and satellite-estimated lake depth values for the lake under study.

  13. Pit lake lime dosing: Assessment of the performance of the treatment based on a high-spatial resolution AUV survey

    Science.gov (United States)

    Delgado, Jordi; García-Morrondo, David; Cereijo-Arango, José Luis; Muñoz-Ibáñez, Andrea; Grande-García, Elisa; Rodríguez-Cedrún, Borja; Juncosa-Rivera, Ricardo

    2016-04-01

    water quality parameters (temperature, pH, electrical conductivity, dissolved oxygen, redox, turbidity and concentration of chlorophyll) according to prescribed trajectories at constant or variable depth. In the present study, depth was fixed at 1 m below the surface of the lake and two surveys were performed in two consecutive days. Results indicate that the efficiency of lime dosing is limited and, under windy conditions (i.e. when wind-transferred energy exceeds that of the currents associated with the liming system and others present in the lake), liming tends to preferentially concentrate at the leeward side of the lake.

  14. Impact of Illness and Medical Expenditure on Household Consumptions: A Survey in Western China

    Science.gov (United States)

    Fang, Kuangnan; Jiang, Yefei; Shia, BenChang; Ma, Shuangge

    2012-01-01

    Background The main goal of this study is to examine the associations between illness conditions and out-of-pocket medical expenditure with other types of household consumptions. In November and December of 2011, a survey was conducted in three cities in western China, namely Lan Zhou, Gui Lin and Xi An, and their surrounding rural areas. Results Information on demographics, income and consumption was collected on 2,899 households. Data analysis suggested that the presence of household members with chronic diseases was not associated with characteristics of households or household heads. The presence of inpatient treatments was significantly associated with the age of household head (p-value 0.03). The level of per capita medical expense was significantly associated with household size, presence of members younger than 18, older than 65, basic health insurance coverage, per capita income, and household head occupation. Adjusting for confounding effects, the presence of chronic diseases was negatively associated with the amount of basic consumption (p-value 0.02) and the percentage of basic consumption (p-value 0.01), but positively associated with the percentage of insurance expense (p-value 0.02). Medical expenditure was positively associated with all other types of consumptions, including basic, education, saving and investment, entertainment, insurance, durable goods, and alcohol/tobacco. It was negatively associated with the percentage of basic consumption, saving and investment, and insurance. Conclusions Early studies conducted in other Asian countries and rural China found negative associations between illness conditions and medical expenditure with other types of consumptions. This study was conducted in three major cities and surrounding areas in western China, which had not been well investigated in published literature. The observed consumption patterns were different from those in early studies, and the negative associations were not observed. This

  15. Evaporative fractions and elevation effects on stable isotopes of high elevation lakes and streams in arid western Himalaya

    Science.gov (United States)

    Biggs, Trent W.; Lai, Chun-Ta; Chandan, Pankaj; Lee, Raymond Mark; Messina, Alex; Lesher, Rebecca S.; Khatoon, Nisa

    2015-03-01

    Isotopes of oxygen and hydrogen in water from streams, snow, and lakes were used to model the ratio of evaporation to total inflow (E/I) of four high elevation lakes in closed basins in the Indian Himalaya. Air temperature and relative humidity (h) data from meteorological stations and global climate grids (GMAO-MERRA) were used as input to the model. A second model of the volume of inflow during snowmelt constrained the magnitude of seasonal variability in isotopic composition. Similar to other areas of the Himalaya, elevation was a strong determinant of isotopic composition of stream water, suggesting that heavier isotopes rain out at lower elevations. Deuterium excess (d) in stream water suggests that summer precipitation originating from the Bay of Bengal rather than winter precipitation from Central Asia is the dominant source of precipitation. For the largest and deepest lakes (>15 m), E/I was 77-87%, and 18-50% for two shallow lakes (GMAO also produced reasonable E/I values. The results suggest that some lakes in closed basins in the Himalaya lose a significant fraction of their inflow to groundwater, particularly shallow lakes with a low ratio of lake volume to watershed area. Isotopic values from the mainstem of the Indus River suggest that evaporatively enriched waters have limited impact on both wet and dry season discharge at the basin scale. Lakes with a high evaporative fraction may be uniquely sensitive to climate, and isotopic analysis can help identify lakes that may be vulnerable to climate fluctuations and change.

  16. Radiological survey of the inactive uranium-mill tailings at Ambrosia Lake, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Haywood, F.F.; Christian, D.J.; Ellis, B.S.; Hubbard, H.M. Jr.; Lorenzo, D.; Shinpaugh, W.H.

    1980-06-01

    The inactive uranium-mill tailings pile at Ambrosia Lake, New Mexico, contains approximately 1520 Ci of /sup 226/Ra in 2.4 million metric tons of tailings covering an area of 43 hectares. All of the former mill buildings were intact and, at the time of this survey, several were in use. The tailings have not been stabilized, but the crusty surface is reported to be resistant to wind erosion. The average gamma-ray exposure rate 1 m above the tailings is 720 ..mu..R/h while the average rate in the former mill area is 150 ..mu..R/h. The adjacent area, between the mill site, ponds, and tailings pile, has an average exposure rate of 230 ..mu..R/h. Gamma radiation measurements outside these areas, as well as the results of analyses of surface or near-surface sediment and soil samples, show fairly wide dispersion of contamination around the site. The subsurface distribution of /sup 226/Ra in 18 holes drilled at the site, calculated from gamma-ray monitoring data, is presented graphically and compared with measured concentrations in two holes.

  17. Track etch orientation survey in the Cluff Lake area, northern Saskatchewan

    Energy Technology Data Exchange (ETDEWEB)

    Beck, L.S. (Saskatchewan Geological Survey, Regina); Gingrich, J.E.

    1976-05-01

    Track Etch is a recently designed method of uranium exploration that uses small pieces of special plastic film to detect the presence of radon gas emitted by buried uranium deposits. By using a sampling time of at least 25 days, the track etch technique eliminates the problems of sensitivity and fluctuations in background values normally present with other radon detection methods. During the summer of 1974, an orientation survey was carried out over the 'N' zone of Amok (Canada) Limited in the Cluff Lake area of northwestern Saskatchewan. This was the first test of the method in an area of glacial overburden and the results have been encouraging. The 'N' zone consists of several pitchblende-bearing lenses associated with gently dipping fracture zones in paragneisses and granites of Archean or Aphebian age. The mineralized zones have been outlined by drilling and occur at depths ranging from 10 to 100 meters. The mineralized area is covered by sandy till and outwash ranging from a few meters to 20 meters in thickness. Approximately 160 track etch sample cups were placed in shallow holes at the surface at roughly 70-meter centers. Sampling extended well beyond the boundaries of the known ore zone. High track etch values were obtained over the deposit, with a peak anomaly of more than 50 times the background value measured for the surrounding area. (auth)

  18. A comparison of interpolation methods on the basis of data obtained from a bathymetric survey of Lake Vrana, Croatia

    Science.gov (United States)

    Šiljeg, A.; Lozić, S.; Šiljeg, S.

    2015-08-01

    The bathymetric survey of Lake Vrana included a wide range of activities that were performed in several different stages, in accordance with the standards set by the International Hydrographic Organization. The survey was conducted using an integrated measuring system which consisted of three main parts: a single-beam sonar HydroStar 4300 and GPS devices; a Ashtech ProMark 500 base, and a Thales Z-Max® rover. A total of 12 851 points were gathered. In order to find continuous surfaces necessary for analysing the morphology of the bed of Lake Vrana, it was necessary to approximate values in certain areas that were not directly measured, by using an appropriate interpolation method. The main aims of this research were as follows: (a) to compare the efficiency of 14 different interpolation methods and discover the most appropriate interpolators for the development of a raster model; (b) to calculate the surface area and volume of Lake Vrana, and (c) to compare the differences in calculations between separate raster models. The best deterministic method of interpolation was multiquadric RBF (radio basis function), and the best geostatistical method was ordinary cokriging. The root mean square error in both methods measured less than 0.3 m. The quality of the interpolation methods was analysed in two phases. The first phase used only points gathered by bathymetric measurement, while the second phase also included points gathered by photogrammetric restitution. The first bathymetric map of Lake Vrana in Croatia was produced, as well as scenarios of minimum and maximum water levels. The calculation also included the percentage of flooded areas and cadastre plots in the case of a 2 m increase in the water level. The research presented new scientific and methodological data related to the bathymetric features, surface area and volume of Lake Vrana.

  19. Critical loads of atmospheric N deposition for phytoplankton nutrient limitation shifts in western U.S. mountain lakes

    National Research Council Canada - National Science Library

    Williams, Jason J; Lynch, Jason A; Saros, Jasmine E; Labou, Stephanie G

    2017-01-01

    In many oligotrophic mountain lakes, anthropogenic atmospheric nitrogen (N) deposition has increased concentrations of N, a key limiting nutrient, and thereby shifted phytoplankton biomass growth from N limitation to P limitation...

  20. Lake shore and littoral habitat structure: a field survey method and its precision

    Science.gov (United States)

    Until recently, lake physical habitat assessment has been and underemployed tool for assessing lake and reservoir ecological condition. Herein, we outline and evaluate a rapid (2 persons: 1.5-3.5 h) field sampling and analytical approach for quantifying near-shore physical habit...

  1. Pharmaceuticals and other anthropogenic tracers in surface water: a randomized survey of 50 Minnesota lakes.

    Science.gov (United States)

    Ferrey, Mark L; Heiskary, Steven; Grace, Richard; Hamilton, M Coreen; Lueck, April

    2015-11-01

    Water from 50 randomly selected lakes across Minnesota, USA, was analyzed for pharmaceuticals, personal care products, hormones, and other commercial or industrial chemicals in conjunction with the US Environmental Protection Agency's 2012 National Lakes Assessment. Thirty-eight of the 125 chemicals analyzed were detected at least once, all at parts per trillion concentrations. The most widely detected was N,N-diethyl-m-toluamide, present in 48% of the lakes sampled. Amitriptyline, a widely used antidepressant, was found in 28% of the lakes. The endocrine active chemicals bisphenol A, androstenedione, and nonylphenol were found in 42%, 30%, and 10% of the lakes, respectively. Cocaine was found in 32% of the lakes, and its degradation product, benzoylecgonine, was detected at 28% of the locations. Carbadox, an antibiotic used solely in the production of swine, was also present in 28% of the lakes sampled. The means by which these and other chemicals were transported to several of the remote lakes is unclear but may involve atmospheric transport. © 2015 SETAC.

  2. Lake Roosevelt Fisheries Evaluation Program, Part A; Fisheries Creel Survey and Population Status Analysis, 1998 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Spotts, Jim; Shields, John; Underwood, Keith

    2002-05-01

    The Lake Roosevelt Fisheries Evaluation Program is the result of a merger between two projects, the Lake Roosevelt Monitoring Program (BPA No. 8806300) and the Lake Roosevelt Data Collection Project (BPA No. 9404300). These projects were merged in 1996 to continue work historically completed under the separate projects, and is now referred to as the Lake Roosevelt Fisheries Evaluation Program. Creel and angler surveys estimated that anglers made 196,775 trips to Lake Roosevelt during 1998, with an economic value of $8.0 million dollars, based on the Consumer Price Index (CPI). In 1998 it was estimated that 9,980 kokanee salmon, 226,809 rainbow trout, 119,346 walleye, and over 14,000 smallmouth bass and other species were harvested. Creel data indicates that hatchery reared rainbow trout contribute substantially to the Lake Roosevelt fishery. The contribution of kokanee salmon to the creel has not met the expectations of fishery managers to date, and is limited by entrainment from the reservoir, predation, and possible fish culture obstacles. The 1998 Lake Roosevelt Fisheries Creel and Population Analysis Annual Report includes analyses of the relative abundance of fish species, and reservoir habitat relationships (1990-1998). Fisheries surveys (1990-1998) indicate that walleye and burbot populations appear to be increasing, while yellow perch, a preferred walleye prey species, and other prey species are decreasing in abundance. The long term decreasing abundance of yellow perch and other prey species are suspected to be the result of the lack of suitable multiple reservoir elevation spawning and rearing refugia for spring spawning reservoir prey species, resulting from seasonal spring-early summer reservoir elevation manipulations, and walleye predation. Reservoir water management is both directly, and indirectly influencing the success of mitigation hatchery production of kokanee salmon and rainbow trout. Tag return data suggested excessive entrainment occurred in

  3. Evidence for millennial-scale climate change during marine isotope stages 2 and 3 at Little Lake, Western Oregon, U.S.A.

    Science.gov (United States)

    Grigg, L.D.; Whitlock, C.; Dean, W.E.

    2001-01-01

    Pollen and geochemical data from Little Lake, western Oregon, suggest several patterns of millennial-scale environmental change during marine isotope stage (MIS) 2 (14,100-27,600 cal yr B.P.) and the latter part of MIS 3 (27,600-42,500 cal yr B.P.). During MIS 3, a series of transitions between warm- and cold-adapted taxa indicate that temperatures oscillated by ca. 2??-4??C every 1000-3000 yr. Highs and lows in summer insolation during MIS 3 are generally associated with the warmest and coldest intervals. Warm periods at Little Lake correlate with warm sea-surface temperatures in the Santa Barbara Basin. Changes in the strength of the subtropical high and the jet stream may account for synchronous changes at the two sites. During MIS 2, shifts between mesic and xeric subalpine forests suggest changes in precipitation every 1000-3000 yr. Increases in Tsuga heterophylla pollen at 25,000 and 22,000 cal yr B.P. imply brief warmings. Minimum summer insolation and maximum global ice-volumes during MIS 2 correspond to cold and dry conditions. Fluctuations in precipitation at Little Lake do not correlate with changes in the Santa Barbara Basin and may be explained by variations in the strength of the glacial anticyclone and the position of the jet stream. ?? 2001 University of Washington.

  4. Inter- and intra-specific variability in δ13C and δ18O values of freshwater gastropod shells from Lake Lednica, western Poland

    Science.gov (United States)

    Apolinarska, Karina; Pełechaty, Mariusz

    2017-09-01

    This study focuses on the inter- and intra-specific variability in δ13C and δ18O values of shells and opercula of gastropods sampled live from the littoral zone of Lake Lednica, western Poland. The δ13C and δ18O values were measured in individual opercula of Bithynia tentaculata and in shells of Bithynia tentaculata, Gyraulus albus, Gyraulus crista, Lymnaea sp., Physa fontinalis, Radix auricularia, Theodoxus fluviatilis and Valvata cristata. The gastropods selected for the study are among the species most commonly found in European Quaternary lacustrine sediments. The carbon isotope composition of the gastropod shells was species-specific and the same order of species from the most to the least 13C-depleted was observed at all sites sampled. Differences in shell δ13C values between species were similar at all sampling sites, thus the factors influencing shell isotopic composition were interpreted as species-specific. The δ18O values of shells were similar in all the species investigated. Significant intra-specific variability in shell δ13C and δ18O values was observed not only within the populations of Lake Lednica, which can be explained by heterogeneity of δ13C DIC, δ18O water and water temperature between the sites where macrophytes with snails attached were sampled, but also between individuals sampled from restricted areas of the lake's bottom. The latter points to the importance of factors related to the ontogeny of individual gastropods.

  5. Factors affecting diatom dynamics in the alpine lakes of Colbricon (Northern Italy: a 10-year survey

    Directory of Open Access Journals (Sweden)

    Andrea SQUARTINI

    2010-08-01

    Full Text Available Planktonic diatom fluctuations, their diversity and relationships with environmental variables were analyzed for ten consecutive years in Colbricon Superiore and Inferiore, two small high-mountain lakes located in the Paneveggio-Pale di S. Martino Natural Park (Trento, Italy offering the rare opportunity to study two lakes differing only by area and volume and being in this respect in a ratio of 2:1 and 3:1 respectively. The lakes were monitored and sampled monthly, during ten ice-free periods, from 1998 to 2007, to correlate water chemical and physical characteristics with the recorded diversity and abundance of planktonic diatoms. 55 taxa of Bacillariophyceae were found, among which Cyclotella spp., Tabellaria flocculosa and Fragilaria spp. were dominant. Both chemical data and diatom community composition are consistent with well buffered mesotrophic lakes. We found statistical evidence that the development of diatoms was strongly related to the variation of water temperature. Furthermore, several different signatures of the diatom-enviroment relationships arose between the two lakes as e.g., a negative correlation between diatom development and water transparency was occurring in the larger lake only. As a result, the average diatom density recorded over the 10 years period were 1.17 fold higher than in the lower lake which corresponds to a 1.65 fold higher biomass. A size-dependent tighter response of the phytoplankton to chemical parameters appears to operate in the smaller waterbody compared to the larger one.

  6. Great Lakes restoration success through science: U.S. Geological Survey accomplishments 2010 through 2013

    Science.gov (United States)

    ,

    2014-01-01

    The Great Lakes (Superior, Michigan, Huron, Erie, and Ontario) are the largest group of freshwater lakes on Earth and serve as an important source of drinking water, transportation, power, and recreational opportunities for the United States and Canada. They also support an abundant commercial and recreational fishery, are crucial for agriculture, and are essential to the economic vitality of the region. The Great Lakes support a wealth of biological diversity, including over 200 globally rare plants and animals and more than 40 species that are found nowhere else in the world. However, more than a century of environmental degradation has taken a substantial toll on the Great Lakes. To stimulate and promote the goal of a healthy Great Lakes region, President Obama and Congress created the Great Lakes Restoration Initiative (GLRI) in 2009. The GLRI is an interagency collaboration that seeks to address the most significant environmental problems in the Great Lakes ecosystem. The GLRI is composed of five focus areas that address these issues: Cleaning up toxic substances and Areas of Concern,

  7. Release of CO{sub 2} and CH{sub 4} from small wetland lakes in western Siberia

    Energy Technology Data Exchange (ETDEWEB)

    Repo, M.E.; Huttunen, J.T.; Martikainen, P.J. [Univ. of Kuopio, Dept. of Env ironmental Science, FI-70211 Kuopio (Finland); Naumov, A.V.; Chichulin, A.V. [I nst. of Soil Science and Agrochemistry, Russian Academy of Science, 630099 Novos ibirsk (Russian Federation); Lapshina, E.D. [Yugra State Univ., 628012, Khanty-Mansiysk (Russian Federation); Bleuten , W. [Utrecht Univ., Dept. of Physical Geography,3508 TC Utrecht (Netherlands)

    2007-11-15

    CO{sub 2} and CH{sub 4} fluxes were measured from three small wetland lakes located in the middle taiga and forest tundra zones on West Siberian Lowlands (WSL), the world's largest wetland area. Fluxes were measured during summer 2005 using floating chambers and were validated against the thin boundary layer model based on the relationship between gas exchange and wind speed. All studied lakes were supersaturated with CO{sub 2} and CH{sub 4}, and acted on a seasonal basis as sources of these greenhouse gases to the atmosphere. Daily mean CO{sub 2} fluxes measured with chambers ranged from near the zero to 3.1 g CO{sub 2}/m{sup 2}/d and corresponding CH{sub 4} fluxes from 1.1 to 120 mg CH{sub 4}/m{sup 2}/d. CH{sub 4} ebullition (0.65-11 mg CH{sub 4}/m{sup 2}/d) was detected in two of the lakes. Total carbon evasion from the studied lakes during the active season was 23-66 g C/m{sup 2}, of which more than 90% was released as CO{sub 2}-C. The carbon loss per unit area from the studied lakes was of similar magnitude as previously reported values of net carbon uptake of Siberian peatlands. This emphasizes the importance of small water-bodies in the carbon balance of West Siberian landscape.

  8. Global Positioning System surveys of storm-surge sensors deployed during Hurricane Ike, Seadrift, Texas, to Lake Charles, Louisiana, 2008

    Science.gov (United States)

    Payne, Jason; Woodward, Brenda K.; Storm, John B.

    2009-01-01

    The U.S. Geological Survey installed a network of pressure sensors at 65 sites along the Gulf Coast from Seadrift, Texas, northeast to Lake Charles, Louisiana, to record the timing, areal extent, and magnitude of inland storm surge and coastal flooding caused by Hurricane Ike in September 2008. A Global Positioning System was used to obtain elevations of reference marks near each sensor. A combination of real-time kinematic (RTK) and static Global Positioning System surveys were done to obtain elevations of reference marks. Leveling relative to reference marks was done to obtain elevations of sensor orifices above the reference marks. This report summarizes the Global Positioning System data collected and processed to obtain reference mark and storm-sensor-orifice elevations for 59 storm-surge sensors recovered from the original 65 installed as a necessary prelude to computation of storm-surge elevations. National Geodetic Survey benchmarks were used for RTK surveying. Where National Geodetic Survey benchmarks were not within 12 kilometers of a sensor site, static surveying was done. Additional control points for static surveying were in the form of newly established benchmarks or reestablished existing benchmarks. RTK surveying was used to obtain positions and elevations of reference marks for 29 sensor sites. Static surveying was used to obtain positions and elevations of reference marks for 34 sensor sites; four sites were surveyed using both methods. Multiple quality checks on the RTK-survey and static-survey data were applied. The results of all quality checks indicate that the desired elevation accuracy for the surveys of this report, less than 0.1-meter error, was achieved.

  9. Impact of western Siberia heat wave 2012 on greenhouse gases and trace metal concentration in thaw lakes of discontinuous permafrost zone

    Directory of Open Access Journals (Sweden)

    O. S. Pokrovsky

    2013-08-01

    Full Text Available During the anomalously hot summer in 2012, surface air temperatures in Western Siberia were 5 to 15 °C higher than those observed during the previous period of > 30 yr. This unusual climate phenomenon provided an opportunity to examine the effects of short-term natural heating of water in thermokarst ponds and lakes in discontinuous permafrost zones and compare these observations to previous field results obtained when the temperature was normal during the summer of 2010 in the same region. In 2012, thermokarst bodies of water shrank significantly, water levels dropped approximately 50 cm in large lakes and small (2 ponds, and shallow soil depressions disappeared. Based on samples from ~ 40 bodies of water collected previously and in 2012, first-order features of changes in chemical composition in response to increased water temperatures (from 14.1 ± 2.2 to 23.8 ± 2.3 °C in 2010 and 2012, respectively were established. In these thermokarst bodies of water that covered a full range of surface areas, the average conductivity and pH were almost unchanged, whereas dissolved organic carbon (DOC, Cl- and SO42- concentrations were higher by a factor of ~ 2 during summer 2012 compared to periods with normal temperatures. Similarly, most divalent metals and insoluble trivalent and tetravalent elements were more concentrated by a factor of 1.7–2.4 in the summer of 2012 than normal periods. The average concentrations of dissolved CO2 and CH4 during the hot summer of 2012 increased by factors of 1.4 and 4.9, respectively. For most of the trace elements bound to colloids, the degree of colloidal binding decreased by a factor of 1.44 ± 0.33 (for an average of 40 elements during the hot summer of 2012 compared to normal periods. Increases in CO2 and CH4 concentrations with the decreasing size of the body of water were well-pronounced during the hot summer of 2012. The concentrations of CO2 and CH4 rose by factors of 5 and 150, respectively, in small (

  10. Great Lakes prey fish populations: a cross-basin overview of status and trends based on bottom trawl surveys, 1978-2013

    Science.gov (United States)

    Gorman, Owen T.; Weidel, Brian C.

    2014-01-01

    The assessment of Great Lakes prey fish stocks have been conducted annually with bottom trawls since the 1970s by the Great Lakes Science Center, sometimes assisted by partner agencies. These stock assessments provide data on the status and trends of prey fish that are consumed by important commercial and recreational fishes. Although all these annual surveys are conducted using bottom trawls, they differ among the lakes in the proportion of the lake covered, seasonal timing, trawl gear used, and the manner in which the trawl is towed (across or along bottom contours). Because each assessment is unique, population indices were standardized to the highest value for a time series within each lake for the following prey species: Cisco (Coregonus artedi), Bloater (C. hoyi), Rainbow Smelt (Osmerus mordax), Alewife (Alosa pseudoharengus), and Round Goby (Neogobius melanostomus). In this report, standardized indices are presented in graphical form along with synopses to provide a short, informal cross-basin summary of the status and trends of principal prey fishes. There was basin-wide agreement in the trends of age-1 and older biomass for all prey species, with the highest concordance occurring for coregonids and Rainbow Smelt, and weaker concordance for Alewife. For coregonids, the highest biomass occurred from the mid-1980s to the mid-1990s. Rainbow Smelt biomass declined slowly and erratically during the last quarter century. Alewife biomass was generally higher from the early 1980s through 1990s across the Great Lakes, but since the early 1990s, trends have been divergent across the lakes, though there has been a downward trend in all lakes since 2005. Recently, Lake Huron has shown resurgence in biomass of Bloater, achieving 75% of its maximum record in 2012 due to recruitment of a succession of strong and moderate year classes that appeared in 2005-2011. Also, strong recruitment of the 2010 year class of Alewife has led to a sharp increase in biomass of Alewife in

  11. Seasonally dynamic diel vertical migrations of Mysis diluviana, coregonine fishes, and siscowet lake trout in the pelagia of western Lake Superior

    Science.gov (United States)

    Ahrenstorff, Tyler D.; Hrabik, Thomas R.; Stockwell, Jason D.; Yule, Daniel L.; Sass, Greg G.

    2011-01-01

    Diel vertical migrations are common among many aquatic species and are often associated with changing light levels. The underlying mechanisms are generally attributed to optimizing foraging efficiency or growth rates and avoiding predation risk (μ). The objectives of this study were to (1) assess seasonal and interannual changes in vertical migration patterns of three trophic levels in the Lake Superior pelagic food web and (2) examine the mechanisms underlying the observed variability by using models of foraging, growth, and μ. Our results suggest that the opossum shrimp Mysis diluviana, kiyi Coregonus kiyi, and siscowet lake trout Salvelinus namaycush migrate concurrently during each season, but spring migrations are less extensive than summer and fall migrations. In comparison with M. diluviana, kiyis, and siscowets, the migrations by ciscoes C. artedi were not as deep in the water column during the day, regardless of season. Foraging potential and μ probably drive the movement patterns of M. diluviana, while our modeling results indicate that movements by kiyis and ciscoes are related to foraging opportunity and growth potential and receive a lesser influence from μ. The siscowet is an abundant apex predator in the pelagia of Lake Superior and probably undertakes vertical migrations in the water column to optimize foraging efficiency and growth. The concurrent vertical movement patterns of most species are likely to facilitate nutrient transport in this exceedingly oligotrophic ecosystem, and they demonstrate strong linkages between predators and prey. Fishery management strategies should use an ecosystem approach and should consider how altering the densities of long-lived top predators produces cascading effects on the nutrient cycling and energy flow in lower trophic levels.

  12. Hydrobiological Survey of the Bahir Dar Gulf of Lake Tana, Ethiopia

    African Journals Online (AJOL)

    FIRST LADY

    : ... considering the size, peculiarity and importance of the lake and its ..... is also an important factor with significantly lower plankton density associated with the presence of the planktivore fishes. African Research Review Vol. 4(2) April, 2010.

  13. Playa Lakes of the Texas High Plains: A contaminants survey & assessment of biological integrity

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In response to increased interest in the quality of playa lakes and their recognition as valuable wildlife habitat, the Arlington Field Office of the U.S. Fish and...

  14. Sedimentation Survey Report: South Unit, Lake Andes, Charles Mix County, South Dakota.

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report addresses the procedures used to obtain sediment data, how they analyzed the data, and the potential restoration alternatives for Lake Andes. The purpose...

  15. Okefenokee and Banks Lake National Wildlife Refuge 2009 Frog Abnormality Survey Summary

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Summary of frog observations for abnormal conditions at select sites on both Okefenokee and Banks Lake NWRs. During the 2009 summer, STEP students Zach Carter along...

  16. LBA-ECO LC-07 Bathymetric Survey of Floodplain Lake, Lago Curuai, Para, Brazil: 2004

    Data.gov (United States)

    National Aeronautics and Space Administration — The bathymetry data provided represent a continuous surface of interpolated point measurements of depth values of Lago Curuai, an Amazon River floodplain lake,...

  17. Marine Biodiversity in Temperate Western Australia: Multi-Taxon Surveys of Minden and Roe Reefs

    Directory of Open Access Journals (Sweden)

    Zoe Richards

    2016-03-01

    Full Text Available A growing body of evidence indicates that temperate marine ecosystems are being tropicalised due to the poleward extension of tropical species. Such climate mediated changes in species distribution patterns have the potential to profoundly alter temperate communities, as this advance can serve to push temperate taxa, many of which are southern Australian endemics, southward. These changes can lead to cascading effects for the biodiversity and function of coastal ecosystems, including contraction of ranges/habitats of sensitive cool water species. Hence there is growing concern for the future of Australia’s temperate marine biodiversity. Here we examine the diversity and abundance of marine flora and fauna at two reefs near Perth’s metropolitan area—Minden Reef and Roe Reef. We report the presence of 427 species of marine flora and fauna from eight taxon groups occurring in the Perth metropolitan area; at least three species of which appear to be new to science. Our data also extends the known range of 15 species, and in numerous instances, thousands of kilometres south from the Kimberley or Pilbara and verifies that tropicalisation of reef communities in the Perth metropolitan area is occurring. We report the presence of 24 species endemic to south-west Australia that may be at risk of range contractions with continued ocean warming. The results of these surveys add to our knowledge of local nearshore marine environments in the Perth metropolitan area and support the growing body of evidence that indicates a diverse and regionally significant marine fauna occurs in temperate Western Australia. Regular, repeated survey work across seasons is important in order to thoroughly document the status of marine biodiversity in this significant transition zone.

  18. Metagenomic survey for viruses in Western Arctic caribou, Alaska, through iterative assembly of taxonomic units.

    Directory of Open Access Journals (Sweden)

    Anita C Schürch

    Full Text Available Pathogen surveillance in animals does not provide a sufficient level of vigilance because it is generally confined to surveillance of pathogens with known economic impact in domestic animals and practically nonexistent in wildlife species. As most (re-emerging viral infections originate from animal sources, it is important to obtain insight into viral pathogens present in the wildlife reservoir from a public health perspective. When monitoring living, free-ranging wildlife for viruses, sample collection can be challenging and availability of nucleic acids isolated from samples is often limited. The development of viral metagenomics platforms allows a more comprehensive inventory of viruses present in wildlife. We report a metagenomic viral survey of the Western Arctic herd of barren ground caribou (Rangifer tarandus granti in Alaska, USA. The presence of mammalian viruses in eye and nose swabs of 39 free-ranging caribou was investigated by random amplification combined with a metagenomic analysis approach that applied exhaustive iterative assembly of sequencing results to define taxonomic units of each metagenome. Through homology search methods we identified the presence of several mammalian viruses, including different papillomaviruses, a novel parvovirus, polyomavirus, and a virus that potentially represents a member of a novel genus in the family Coronaviridae.

  19. A baseline survey: oral health status of prisoners--Western Cape.

    Science.gov (United States)

    Naidoo, Sudeshni; Yengopal, V; Cohen, B

    2005-02-01

    South African prison populations continue to grow because of the escalating crime and an overstretched judicial system. The aim of this study was to assess the oral health status of prison inmates in the Western Cape (Pollsmoor, Goodwood, Paarl and Worcester). A cross-sectional epidemiological survey involving a clinical oral examination and face-to-face interviews was used to collect information on DMFT, periodontal health, perceived needs and the knowledge, attitudes and behaviour of inmates to oral health. Clinical examinations were carried out using WHO criteria. Of the 340 study participants, 264 were male and 76 were female. The prevalence of oral disease was high. The mean DMFT was 15.45 and the total DMFT increased with age. There was a reported impact on oral health quality of life, with many citing problems with eating, drinking and pain. Self-reported dental needs indicated a perceived need for dentures, scaling and fillings. Over two thirds of the sample (72%) reported that the dental services that they presently receive are poor. This study found a high prevalence of dental caries and periodontal disease among the correctional service populations. There is an urgent need for the development of a basic oral health care package that should be offered to all inmates as eventually many of them will be returning to the community.

  20. A Survey of Dutch Expert Opinion on Climatic Drivers of Infectious Disease Risk in Western Europe

    Directory of Open Access Journals (Sweden)

    Su-Mia Akin

    2014-11-01

    Full Text Available Climate change is considered to be a significant influence for infectious disease risk in Western Europe. Climatic and non-climatic developments act together resulting in current and future infectious disease risk. This study uses a survey to explore Dutch expert perspectives on climate change induced infectious disease risk. The results show that the experts consider temperature change, precipitation change, humidity change, and climate change induced habitat change to be relatively important for water-related infectious disease risk, vector-borne disease risk excluding zoonoses, and the risk of zoonoses. The climatic drivers are seen as relatively less important for food-related infectious disease risk. The experts rate many non-climatic drivers to be highly important for infectious disease risk. Comparatively, the majority of the non-climatic drivers assessed are seen as more important than climate change drivers. The degree of uncertainty in the future development of climatic drivers is viewed as moderate to high, and for non-climatic drivers mostly as moderate. An analysis of subsamples based on professional backgrounds reveals differences in experts’ opinions for e.g., socio-cultural drivers, and similarities. Diversity and consensus amongst expert perspectives on climate change and infectious diseases can have implications for policy. Further research to uncover and compare prevailing perspectives is necessary.

  1. About viral hemorrhagic septicemia (VHS) virus. Potential threat of Great Lakes VHS virus in Western United States

    Science.gov (United States)

    Bartholomew, Jerri L; Kurath, Gael; Emmenegger, Evi

    2011-01-01

    Viral hemorrhagic septicemia (VHS) is a disease caused by a virus (VHSV). There are different strains of the virus that can infect marine and freshwater fish species, and the different strains may affect species differently. VHSV has recently invaded the Great Lakes, resulting in many large-scale fish die-offs and new regulatory restrictions for aquaculture throughout the region.

  2. On-Farm Water Recycling as an Adaptation Strategy for Drained Agricultural Land in the Western Lake Erie Basin

    Science.gov (United States)

    On-farm water recycling is in agricultural landscapes today, and a few examples exist in the Great Lakes region. They have been implemented primarily where both irrigation is needed for high value crops and groundwater is inadequate to provide the rates needed. Crop yield benefits of irrigation fr...

  3. Presence of Potential Toxin-Producing Cyanobacteria in an Oligo-Mesotrophic Lake in Baltic Lake District, Germany: An Ecological, Genetic and Toxicological Survey

    OpenAIRE

    Dadheech, Pawan K.; Selmeczy, Géza B.; Vasas, Gábor; Padisák, Judit; Arp, Wolfgang; Tapolczai, Kálmán; Casper, Peter; Krienitz, Lothar

    2014-01-01

    Massive developments of potentially toxic cyanobacteria in Lake Stechlin, an oligo-mesotrophic lake in the Baltic Lake District of Germany raised concerns about toxic contamination of these important ecosystems. Field samples in the phase of mass developments of cyanobacteria were used for genetic and toxicological analyses. Microcystins and microcystin genes were detected in field samples of the lake for the first time. However, the toxins were not produced by the dominant taxa (Dolichosper...

  4. Regional Lake Surveys in The Barents region of Finland - Norway - Sweden and Russian Kola 1995 - Results

    Energy Technology Data Exchange (ETDEWEB)

    Henriksen, Arne; Mannio, Jaakko; Wilander, Anders; Moiseenko, Tatyana; Traaen, Tor S.; Skjelkvaale, Brit Lisa; Fjeld, Eirik; Vuorenmaa, Jussi

    1997-12-31

    Because of the special interests in the local resources in the Barents area, a project has been done to evaluate the chemical properties of the lakes within this area of Norway, Sweden, Finland and Russia. This report discusses the results. In general, the lakes in the Norwegian, Swedish and Finish parts are less acid than the lakes in these countries as a whole. The most acid lakes are found in Russian Kola, where the organic carbon content is also greatest. The nitrate concentrations are generally lower in the Barents region than in the countries as a whole, which agrees well with the low nitrogen depositions in the Barents region. The critical loads of acidity in the region are highest in Norway and much higher than for the whole country. For Finland and Sweden the opposite is the case. The critical loads are exceeded in the Barents region, the highest percentages are found in Russian Kola (14%) and in Norway (12%) while Sweden has the lowest percentage (3%). It is found that the lakes in the are respond rapidly to reduced sulphur deposition. The planned reconstruction of the ``Pechenganikel`` smelter will significantly reduce the emissions of sulphur and heavy metals and so reduce the adverse effects on the ecosystems in the area. It is important to continue environmental research and monitoring in the border area in order to study the reversibility of acidification and to what extent actions will be sufficient. 23 refs., 11 figs., 4 tabs.

  5. Comparison of benthos and plankton for selected areas of concern and non-areas of concern in western Lake Michigan Rivers and Harbors in 2012

    Science.gov (United States)

    Eikenberry, Barbara C. Scudder; Bell, Amanda H.; Templar, Hayley A.; Burns, Daniel J.

    2016-07-25

    Recent data are lacking to assess whether impairments still exist at four of Wisconsin’s largest Lake Michigan harbors that were designated as Areas of Concern (AOCs) in the late 1980s due to sediment contamination and multiple Beneficial Use Impairments (BUIs), such as those affecting benthos (macroinvertebrates) and plankton (zooplankton and phytoplankton) communities. During three seasonal sampling events (“seasons”) in May through August 2012, the U.S. Geological Survey collected sediment benthos and water plankton at the four AOCs as well as six less-degraded non-AOCs along the western Lake Michigan shoreline to assess whether AOC communities were degraded in comparison to non-AOC communities. The four AOCs are the Lower Menominee River, the Lower Green Bay and Fox River, the Sheboygan River, and the Milwaukee Estuary. Due to their size and complexity, multiple locations or “subsites” were sampled within the Lower Green Bay and Fox River AOC (Lower Green Bay, the Fox River near Allouez, and the Fox River near De Pere) and within the Milwaukee Estuary AOC (the Milwaukee River, the Menomonee River, and the Milwaukee Harbor) and single locations were sampled at the other AOCs and non-AOCs. The six non-AOCs are the Escanaba River in Michigan, and the Oconto River, Ahnapee River, Kewaunee River, Manitowoc River, and Root River in Wisconsin. Benthos samples were collected by using Hester-Dendy artificial substrates deployed for 30 days and by using a dredge sampler; zooplankton were collected by net and phytoplankton by whole-water sampler. Except for the Lower Green Bay and Milwaukee Harbor locations, communities at each AOC were compared to all non-AOCs as a group and to paired non-AOCs using taxa relative abundances and metrics, including richness, diversity, and an Index of Biotic Integrity (IBI, for Hester-Dendy samples only). Benthos samples collected during one or more seasons were rated as degraded for at least one metric at all AOCs. In the

  6. Survey on maize post-harvest losses and its management practices in the western hills of Nepal

    Directory of Open Access Journals (Sweden)

    Ghanashyam Bhandari

    2015-12-01

    Full Text Available A survey was conducted in order to assess the losses of maize under farmers’ storage conditions in the Western hills of Nepal in 2014. The survey area included Thanapati Village Development Committee (VDC of Gulmi, Aalamdebi VDC of Syangja, Khasauli VDC of Palpa and Baglung municipality-12, Baglung district. Primary information was collected through semi-structured questionnaires among the heterogenous groups of the farming communities. Survey revealed that about 61% respondents reported the storage pest as the major pests and about 12% respondents reported that field pests as the major pests in the western hills. Maize weevil (Sitophylus zeamais Mostsch. and Angoumois grain moth (Sitotroga cerealella Oliv. were found to be major storage insect pests in surveyed areas. Majority of respondents (39% presumed on 10-20% losses during storage. Among the other biotic factors, farmers ranked insect (42%, weeds (32% and diseases (17% respectively. Maize storage methods had distinct among the surveyed areas compared with Baglung district to other surveyed areas. In Baglung, about (73% farmers had stored maize in the form of grain whereas in Palpa, Gulmi and Syangja, about (77% farmers had practice of storing maize with husk for 5-7 months. Approximately, 40% respondents were using open floor in upper stair “Aanti”as a major maize storage place in Palpa, Gulmi and Syangja whereas almost (79% of respondents were using sacks to store shelled grains in Baglung. Hence, there is ample opportunity to reduce the storage losses of maize depending upon the existing situation.

  7. National Lakes Assessment Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — The National Lakes Assessment (NLA) is a first-ever statistically-valid survey of the biological condition of lakes and reservoirs throughout the U.S. The U.S....

  8. Effects of land use and geohydrology on the quality of shallow ground water in two agricultural areas in the western Lake Michigan drainages, Wisconsin

    Science.gov (United States)

    Saad, David A.

    1997-01-01

    Water-quality and geohydrologic data were collected between September 1993 and September 1994, from 56 wells and 2 springs, in two agricultural areas in the Western Lake Michigan Drainages study unit of the National-Water Quality Assessment Program. These data were used to study the effects of land use and geohydrology on shallow ground-water quality. Water samples from each well and spring were analyzed for major ions, nutrients, dissolved organic carbon, pesticides, volatile organic compounds, oxygen and hydrogen isotopes, and uranium; measurements of temperature, pH, specific conductance, and dissolved oxygen were made in the field. Ground-water samples were also analyzed for tritium or chlorofluorocarbons, or both, to estimate the recharge date of the ground water. Slug tests were performed on most of the wells to estimate the hydraulic conductivity of the surficial deposits in the vicinity of the well.

  9. Current-use pesticides and organochlorine compounds in precipitation and lake sediment from two high-elevation national parks in the Western United States

    Science.gov (United States)

    Mast, M.A.; Foreman, W.T.; Skaates, S.V.

    2007-01-01

    Current-use pesticides (CUPs) and banned organochlorine compounds (OCCs) were measured in precipitation (snowpack and rain) and lake sediments from two national parks in the Western United States to determine their occurrence and distribution in high-elevation environments. CUPs frequently detected in snow were endosulfan, dacthal, and chlorothalonil in concentrations ranging from 0.07 to 2.4 ng/L. Of the OCCs, chlordane, hexachlorobenzene, and two polychlorinated biphenyl congeners were detected in only one snow sample each. Pesticides most frequently detected in rain were atrazine, carbaryl, and dacthal in concentrations from 3.0 to 95 ng/L. Estimated annual deposition rates in one of the parks were 8.4 ??g/m2 for atrazine, 9.9 ??g/m2 for carbaryl, and 2.6 ??g/m2 for dacthal, of which >85% occurred during summer. p,p'-DDE and p,p'-DDD were the most frequently detected OCCs in surface sediments from lakes. However, concentrations were low (0.12 to 4.7 ??g/kg) and below levels at which harmful effects for benthic organisms are likely to be observed. DDD and DDE concentrations in an age-dated sediment core suggest that atmospheric deposition of DDT and its degradates, and possibly other banned OCCs, to high-elevation areas have been decreasing since the 1970s. Dacthal and endosulfan sulfate were present in low concentrations (0.11 to 1.2 ??g/kg) and were the only CUPs detected in surface sediments. Both pesticides were frequently detected in snow, confirming that some CUPs entering high-elevation aquatic environments through atmospheric deposition are accumulating in lake sediments and potentially in aquatic biota as well. ?? 2007 Springer Science+Business Media, Inc.

  10. Fall diets of red-breasted merganser (Mergus serrator) and walleye (Sander vitreus) in Sandusky Bay and adjacent waters of western Lake Erie

    Science.gov (United States)

    Bur, M.T.; Stapanian, M.A.; Bernhardt, G.; Turner, M.W.

    2008-01-01

    Although published studies indicate the contrary, there is concern among many sport anglers that migrating red-breasted mergansers (Mergus serrator) and other waterbirds pose a competitive threat to sport fish species such as walleye (Sander vitreus) in Lake Erie. We quantified the diet of autumn-migrant mergansers and walleye during 1998-2000 in Sandusky Bay and adjacent waters of western Lake Erie. We hypothesized that the diets of both predators would be similar in species composition, but because of different foraging ecologies their diets would differ markedly in size of prey consumed. In addition to predator samples, we used trawl data from the same general area as an index of prey availability. We found that mergansers fed almost exclusively on fish (nine species). Gizzard shad (Dorosoma cepedianum), emerald shiner (Notropis atherinoides) and round goby (Neogobius melanostomus) were consumed in the greatest numbers, most frequently and comprised the greatest biomass. Walleye fed exclusively on fish: gizzard shad, alewife (Alosa psuedoharengus) and emerald shiner were consumed in the greatest numbers, most frequently and comprised the greatest biomass. Diet overlap between mergansers and walleye was 67% by weight and 66% by species frequency. Mean total lengths of gizzard shad, emerald shiner and round goby found in walleye stomachs exceeded those captured in trawls by 47%, on average. Mean total lengths of gizzard shad, emerald shiner and round goby were greater in walleye stomachs than in merganser stomachs. Mean total lengths of emerald shiner and round goby were less in merganser stomachs than in trawls. Our results suggest that although the diets of walleye and mergansers overlapped considerably, mergansers generally consumed smaller fish than walleye. Given the abundance and diversity of prey species available, and the transient nature of mergansers on Lake Erie during migration, we conclude that competition for food between these species is minimal.

  11. SHRIMP U-Pb ages of xenotime and monazite from the Spar Lake red bed-associated Cu-Ag deposit, western Montana: Implications for ore genesis

    Science.gov (United States)

    Aleinikoff, John N.; Hayes, Timothy S.; Evans, Karl V.; Mazdab, Frank K.; Pillers, Renee M.; Fanning, C. Mark

    2012-01-01

    Xenotime occurs as epitaxial overgrowths on detrital zircons in the Mesoproterozoic Revett Formation (Belt Supergroup) at the Spar Lake red bed-associated Cu-Ag deposit, western Montana. The deposit formed during diagenesis of Revett strata, where oxidizing metal-bearing hydrothermal fluids encountered a reducing zone. Samples for geochronology were collected from several mineral zones. Xenotime overgrowths (1–30 μm wide) were found in polished thin sections from five ore and near-ore zones (chalcocite-chlorite, bornite-calcite, galena-calcite, chalcopyrite-ankerite, and pyrite-calcite), but not in more distant zones across the region. Thirty-two in situ SHRIMP U-Pb analyses on xenotime overgrowths yield a weighted average of 207Pb/206Pb ages of 1409 ± 8 Ma, interpreted as the time of mineralization. This age is about 40 to 60 m.y. after deposition of the Revett Formation. Six other xenotime overgrowths formed during a younger event at 1304 ± 19 Ma. Several isolated grains of xenotime have 207Pb/206Pb ages in the range of 1.67 to 1.51 Ga, and thus are considered detrital in origin. Trace element data can distinguish Spar Lake xenotimes of different origins. Based on in situ SHRIMP analysis, detrital xenotime has heavy rare earth elements-enriched patterns similar to those of igneous xenotime, whereas xenotime overgrowths of inferred hydrothermal origin have hump-shaped (i.e., middle rare earth elements-enriched) patterns. The two ages of hydrothermal xenotime can be distinguished by slightly different rare earth elements patterns. In addition, 1409 Ma xenotime overgrowths have higher Eu and Gd contents than the 1304 Ma overgrowths. Most xenotime overgrowths from the Spar Lake deposit have elevated As concentrations, further suggesting a genetic relationship between the xenotime formation and Cu-Ag mineralization.

  12. Astronomical Site Survey for Mountain Wumingshan Area in Western Sichuan Based on GIS

    Science.gov (United States)

    Wu, N.; Liu, Y.; Zhao, H. M.

    2016-11-01

    In the Western-China Astronomical Site Survey project, we utilize the Geographic Information System (GIS) for the collection of long-term data, in order to investigate and study the Wumingshan (WMS) mountain and its surrounding areas for their geography, geology, climate, meteorology, social and demographic trends. Data analysis results show that the WMS mountain is located in the eastern fold belt of the Tibet Plateau--the typical region of the Hengduan Mountains, which leads to its large elevation, gently trended ridge, and stable geological structure. The highest altitude above the sea level at the WMS is more than 5000 m, but there are population settlements nearby with the low altitude of only 2000-3000 m, which are important for realizing low-level cost logistics conditions for the future headquarter or logistic base. Earthquake landslides and other geological disasters were rarely recorded. The other facts are such as the dry and clean atmosphere, the sparse vegetation, the semi-dry-state land, the perennial prevailing southwest wind, the rain-less winter, and the relatively short rainy-season summer, the location in the heartland of the large Shangri-La, no records of dust storms and the other inclement weather, low cloud coverage, the stability of wind direction, the small wind speed, the high possibility of clear sky, the far distance away from the developed areas in Sichuan and Yunnan provinces, and Tibet Autonomous Region, the sparsely populated people, the slowly developed economy, the peaceful and stable social environment, etc. Specially, in recent years, with the development of the local tourist resources, the traffic conditions in Daocheng have been significantly improved. With high quality highway maintenance and daily air transport capacity, the transportation of land and aviation is rarely interrupted due to snowing, which often happens in high plateau regions. Therefore, the WMS area possesses the potential conditions to establish the future

  13. Hydrological and ecological changes in western Europe between 3200 and 2000 years BP derived from lipid biomarker δD values in lake Meerfelder Maar sediments

    Science.gov (United States)

    Rach, O.; Engels, S.; Kahmen, A.; Brauer, A.; Martín-Puertas, C.; van Geel, B.; Sachse, D.

    2017-09-01

    One of the most significant Late Holocene climate shifts occurred around 2800 years ago, when cooler and wetter climate conditions established in western Europe. This shift coincided with an abrupt change in regional atmospheric circulation between 2760 and 2560 cal years BP, which has been linked to a grand solar minimum with the same duration (the Homeric Minimum). We investigated the temporal sequence of hydroclimatic and vegetation changes across this interval of climatic change (Homeric climate oscillation) by using lipid biomarker stable hydrogen isotope ratios (δD values) and pollen assemblages from the annually-laminated sediment record from lake Meerfelder Maar (Germany). Over the investigated interval (3200-2000 varve years BP), terrestrial lipid biomarker δD showed a gradual trend to more negative values, consistent with the western Europe long-term climate trend of the Late Holocene. At ca. 2640 varve years BP we identified a strong increase in aquatic plants and algal remains, indicating a rapid change in the aquatic ecosystem superimposed on this long-term trend. Interestingly, this aquatic ecosystem change was accompanied by large changes in δD values of aquatic lipid biomarkers, such as nC21 and nC23 (by between 22 and 30‰). As these variations cannot solely be explained by hydroclimate changes, we suggest that these changes in the δDaq value were influenced by changes in n-alkane source organisms. Our results illustrate that if ubiquitous aquatic lipid biomarkers are derived from a limited pool of organisms, changes in lake ecology can be a driving factor for variations on sedimentary lipid δDaq values, which then could be easily misinterpreted in terms of hydroclimatic changes.

  14. SURVEY ON THE PRESENCE OF POLYCHLOROBIPHENYLS (PCBs ON FISHES OF PIEDILUCO LAKE (TERNI, CENTRAL ITALY

    Directory of Open Access Journals (Sweden)

    M. Latini

    2013-02-01

    Full Text Available During the period 2004-2006, 254 specimen belonging to Ciprinidae, Percidae and Anguillidae fishes of Piediluco Lake were analyzed by gas chromatography to check for the presence of PCBs contamination. Data obtained show low level of contamination with a decreasing trend from 2004 to 2006.

  15. Rockfall risk evaluation using geotechnical survey, remote sensing data, and GIS: a case study from western Greece

    Science.gov (United States)

    Nikolakopoulos, Konstantinos; Depountis, Nikolaos; Vagenas, Nikolaos; Kavoura, Katerina; Vlaxaki, Eleni; Kelasidis, George; Sabatakakis, Nikolaos

    2015-06-01

    In this paper a specific example of the synergistic use of geotechnical survey, remote sensing data and GIS for rockfall risk evaluation is presented. The study area is located in Western Greece. Extensive rockfalls have been recorded along Patras - Ioannina highway just after the cable-stayed bridge of Rio-Antirrio, at Klokova site. The rockfalls include medium- sized limestone boulders with volume up to 1.5m3. A detailed engineering geological survey was conducted including rockmass characterization, laboratory testing and geological - geotechnical mapping. Many Rockfall trajectory simulations were done. Rockfall risk along the road was estimated using spatial analysis in a GIS environment.

  16. Combined use of frequency‐domain electromagnetic and electrical resistivity surveys to delineate the freshwater/saltwater interface near saline lakes in the Nebraska Sand Hills, Nebraska, USA

    Science.gov (United States)

    Ong, John T.; White, Eric A.; Lane, John; Halihan, Todd; Zlotnik, Vitaly A; Butler, Dwain K.

    2009-01-01

    We investigate the use of frequency‐domain electromagnetic (FDEM) and electrical resistivity (ER) surveys for rapid and detailed characterization of the direction of lake‐aquifer fluxes and the configuration of salt plumes generated from saline lakes. This methodology was developed and applied at several lakes in the Nebraska Sand Hills, Nebraska, in an area with both freshwater and saline lakes hydraulically connected to the freshwater surficial aquifer. The FDEM survey was conducted by mounting the instrument on a fiberglass cart towed by an all‐terrain vehicle. The towed FDEM surveys covered about 25 km per day and served as a reconnaissance method for choosing locations for the more quantitative and detailed ER surveys. Around the saline lakes, areas with high electrical conductivity are consistent with the regional direction of ground‐water flow. Lower electrical conductivity was measured around the freshwater lakes with anomalies correlating to a paleovalley axis inferred from previous studies. The efficacy of this geophysical approach is attributed to: (1) significant contrast in electrical conductivity between freshwater and saltwater, (2) near‐surface location of the freshwater/saltwater interface, (3) minimal cultural interference, and (4) relative homogeneity of the aquifer materials.

  17. Hydrophysical and hydrochemical features of Lake Issyk-Kul (Kyrgyzstan) as revealed by field survey of June, 2015

    Science.gov (United States)

    Zavialov, Peter; Makkaveev, Petr; Rimskiy-Korsakov, Nikolay; Alymkulov, Salmor; Izhitskiy, Alexander

    2016-04-01

    Lake Issyk-Kul is a major (volume 1700 km3, depth 668 m) terminal lake in Kyrgyzstan, Central Asia. The lake has a longstanding history of research and recently attracted international attention, in particular, as a potentially promising site for scientific drilling and reconstructing paleo-climate variability (e.g., Oberhansli and Molnar, 2012). However, the in situ hydrophysical and hydrochemical data collected from Issyk-Kul are still limited, and those available are somewhat outdated, given that the most recent field campaign reported in the literature dates back to about 15 years ago. A new field survey was conducted in June, 2015. The measurements included CTD profiling and water sampling at 19 stations in all parts of the lake, as well as continuous measurements by a pump-through system and an ultraviolet lidar along the ship's track. The water samples were analyzed for a variety of hydrochemical indicators, including nutrients, dissolved oxygen and methane. In addition, velocity meters were deployed at 3 mooring stations to investigate the synoptic variability of currents. The nitrates, nitrites, phosphorus and silica exhibited elevated surface concentrations in the central part of the lake, which is likely to be associated with the upwelling induced by the basin-wide cyclonic circulation gyre evident from the current measurements. At the same time, the coastal waters were characterized by very low content of nutrients, except the southeastern part of the lake exposed to significant continental discharges from the Tyup and the Dzhergalan rivers. In the areas of continental water influence, concentration of dissolved silica attained minimum values in the surface and intermediate layers. On the other hand, silica concentrations grew steadily from the depth of about 100 m down to the bottom. In general, concentrations of principal biogenic elements in the euphotic layer were relatively low - albeit not low enough to be a limiting factor for phytoplankton life

  18. Extensive lake sediment coring survey on Sub-Antarctic Indian Ocean Kerguelen Archipelago (French Austral and Antarctic Lands)

    Science.gov (United States)

    Arnaud, Fabien; Fanget, Bernard; Malet, Emmanuel; Poulenard, Jérôme; Støren, Eivind; Leloup, Anouk; Bakke, Jostein; Sabatier, Pierre

    2016-04-01

    Recent paleo-studies revealed climatic southern high latitude climate evolution patterns that are crucial to understand the global climate evolution(1,2). Among others the strength and north-south shifts of westerlies wind appeared to be a key parameter(3). However, virtually no lands are located south of the 45th South parallel between Southern Georgia (60°W) and New Zealand (170°E) precluding the establishment of paleoclimate records of past westerlies dynamics. Located around 50°S and 70°E, lost in the middle of the sub-Antarctic Indian Ocean, Kerguelen archipelago is a major, geomorphologically complex, land-mass that is covered by hundreds lakes of various sizes. It hence offers a unique opportunity to reconstruct past climate and environment dynamics in a region where virtually nothing is known about it, except the remarkable recent reconstructions based on a Lateglacial peatbog sequence(4). During the 2014-2015 austral summer, a French-Norwegian team led the very first extensive lake sediment coring survey on Kerguelen Archipelago under the umbrella of the PALAS program supported by the French Polar Institute (IPEV). Two main areas were investigated: i) the southwest of the mainland, so-called Golfe du Morbihan, where glaciers are currently absent and ii) the northernmost Kerguelen mainland peninsula so-called Loranchet, where cirque glaciers are still present. This double-target strategy aims at reconstructing various independent indirect records of precipitation (glacier advance, flood dynamics) and wind speed (marine spray chemical species, wind-borne terrigenous input) to tackle the Holocene climate variability. Despite particularly harsh climate conditions and difficult logistics matters, we were able to core 6 lake sediment sites: 5 in Golfe du Morbihan and one in Loranchet peninsula. Among them two sequences taken in the 4km-long Lake Armor using a UWITEC re-entry piston coring system by 20 and 100m water-depth (6 and 7m-long, respectively). One

  19. Paleoflood activity and climate change over the last 2000 years recorded by high altitude alpine lake sediments in Western French Alps.

    Science.gov (United States)

    Fouinat, Laurent; Sabatier, Pierre; Develle, Anne-Lise; Giguet-Covex, Charline; Poulenard, Jérôme; Doyen, Elise; Crouzet, Christian; Malet, Emmanuel; Reyss, Jean-Louis; Arnaud, Fabien

    2015-04-01

    Extreme precipitation events can trigger floods that may have serious human and economic consequences. The flood represents extreme rainfall event, which in high altitude mountain regions are mostly triggered alternatively by local convective summer storms or, less frequently, by regional widespread rainfall event. The former's precipitation pattern comes from Mediterranean Sea fluxes, dominant in the south; instead of the latter coming from the Atlantic Ocean, dominant in the north of the French Alps. The aim of the study is then to explore which regime dominates in Western French Alps. Paleoflood chronicle is a way to understand past continental climate through the variability of both frequency and intensity. In this study we explore the paleoflood activity as recorded by sediments of the small alpine lake Muzelle (2200 m.a.s.l.) located in the western French Alps. Lake Muzelle catchment area is 5 km² -around 4 % being glacier covered- and is drained by one main stream. Lake Muzelle is 18.8 meters deep and is ice-covered during 7-8 months each year. Moreover, the watershed is being used for pastoral activity for several centuries. In this study, we use sedimentological analysis as well high resolution XRF core scanner geochemistry to identify turbidites interpreted as flood deposits. 256 turbidites were documented in the sediment sequence. Sr/Ti geochemical ratio is used to identify the coarsest grain size fraction of the flood deposit and the thickness of each deposit was measured. Dating was carried out using short-lived-radio-elements (210Pb, 137Cs, 241Am), historical events as well as nine 14C dates and paleomagnetic declination to constrain the age model over the last 2000 years. The study includes also palynological and sediment DNA analysis to understand past human activity on the watershed. As a result, the 31 years frequency shows a stable period from 0 to 1100 AD. Between 1100 and1200 AD the flood frequency presents a brutal increase with a relatively

  20. The sero-epidemiology of Rift Valley fever in people in the Lake Victoria Basin of western Kenya

    Science.gov (United States)

    Grossi-Soyster, Elysse Noel; de Glanville, William Anson; Thomas, Lian Francesca; Kariuki, Samuel; Bronsvoort, Barend Mark de Clare; Wamae, Claire Njeri; LaBeaud, Angelle Desiree; Fèvre, Eric Maurice

    2017-01-01

    Rift Valley fever virus (RVFV) is a zoonotic arbovirus affecting livestock and people. This study was conducted in western Kenya where RVFV outbreaks have not previously been reported. The aims were to document the seroprevalence and risk factors for RVFV antibodies in a community-based sample from western Kenya and compare this with slaughterhouse workers in the same region who are considered a high-risk group for RVFV exposure. The study was conducted in western Kenya between July 2010 and November 2012. Individuals were recruited from randomly selected homesteads and a census of slaughterhouses. Structured questionnaire tools were used to collect information on demographic data, health, and risk factors for zoonotic disease exposure. Indirect ELISA on serum samples determined seropositivity to RVFV. Risk factor analysis for RVFV seropositivity was conducted using multi-level logistic regression. A total of 1861 individuals were sampled in 384 homesteads. The seroprevalence of RVFV in the community was 0.8% (95% CI 0.5–1.3). The variables significantly associated with RVFV seropositivity in the community were increasing age (OR 1.2; 95% CI 1.1–1.4, pslaughterhouse workers were sampled in 84 ruminant slaughterhouses. The seroprevalence of RVFV in slaughterhouse workers was 2.5% (95% CI 1.5–4.2). Being the slaughterman, the person who cuts the animal’s throat (OR 3.5; 95% CI 1.0–12.1, p = 0.047), was significantly associated with RVFV seropositivity. This study investigated and compared the epidemiology of RVFV between community members and slaughterhouse workers in western Kenya. The data demonstrate that slaughtering animals is a risk factor for RVFV seropositivity and that slaughterhouse workers are a high-risk group for RVFV seropositivity in this environment. These risk factors have been previously reported in other studies providing further evidence for RVFV circulation in western Kenya. PMID:28686589

  1. Willapa NWR: Initial Survey Instructions for Western Snowy Plover Monitoring - Habitat

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Western snowy plover numbers have declined along the U.S. Pacific coast due to habitat degradation and expanding predator populations. One of the most significant...

  2. Willapa NWR: Initial Survey Instructions for Western Snowy Plover Monitoring - Nest Success

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — On March 5, 1993, the Pacific Coast population of the western snowy plover was federally listed as threatened under the Endangered Species Act of 1973 (16 U.S.C....

  3. Home delivery and newborn care practices among urban women in western Nepal: a questionnaire survey

    Directory of Open Access Journals (Sweden)

    Giri Sabitri

    2006-08-01

    Full Text Available Abstract Background About 98% of newborn deaths occur in developing countries, where most newborns deaths occur at home. In Nepal, approximately, 90% of deliveries take place at home. Information about reasons for delivering at home and newborn care practices in urban areas of Nepal is lacking and such information will be useful for policy makers. Methods A cross-sectional survey was carried out in the immunisation clinics of Pokhara city, western Nepal during January and February, 2006. Two trained health workers administered a semi-structured questionnaire to the mothers who had delivered at home. Results A total of 240 mothers were interviewed. Planned home deliveries were 140 (58.3% and 100 (41.7% were unplanned. Only 6.2% of deliveries had a skilled birth attendant present and 38 (15.8% mothers gave birth alone. Only 46 (16.2% women had used a clean home delivery kit and only 92 (38.3% birth attendants had washed their hands. The umbilical cord was cut after expulsion of placenta in 154 (64.2% deliveries and cord was cut using a new/boiled blade in 217 (90.4% deliveries. Mustard oil was applied to the umbilical cord in 53 (22.1% deliveries. Birth place was heated throughout the delivery in 88 (64.2% deliveries. Only 100 (45.8% newborns were wrapped within 10 minutes and 233 (97.1% were wrapped within 30 minutes. Majority (93.8% of the newborns were given a bath soon after birth. Mustard oil massage of the newborns was a common practice (144, 60%. Sixteen (10.8% mothers did not feed colostrum to their babies. Prelacteal feeds were given to 37(15.2% newborns. Initiation rates of breast-feeding were 57.9% within one hour and 85.4% within 24 hours. Main reasons cited for delivering at home were 'preference' (25.7%, 'ease and convenience' (21.4% for planned deliveries while 'precipitate labor' (51%, 'lack of transportation' (18% and 'lack of escort' during labor (11% were cited for the unplanned ones. Conclusion High-risk home delivery and

  4. Preliminary report of mosquitoes survey at Tonga Lake (North-East Algeria)

    OpenAIRE

    Amara Korba, Raouf; Boukraa, Slimane; Alayat, Moufdia Saoucen; Bendjeddou, Mohamed Lamine; Francis, Frédéric; Boubidi, Said Chawki; Bouslama, Zihad

    2016-01-01

    Background: Mosquitoes are transmitters of several human diseases including, malaria, filariasis, West Nile virus and Rift Valley fever virus. To planified and succeful any mosquito vector control, a good understanding of the occurrence of specific important vector species, their abundance and distribution are needed. Objectives: The present study aimed to identify the mosquito potential vectors distributed throughout Tonga Lake region, a part of National Park of El-Kala situated in northeast...

  5. Regional trends in evaporation loss and water yield based on stable isotope mass balance of lakes: The Ontario Precambrian Shield surveys

    Science.gov (United States)

    Gibson, J. J.; Birks, S. J.; Jeffries, D.; Yi, Y.

    2017-01-01

    , although it likely has only a minor influence on regional survey results. While further analysis in gauged lake watersheds would be beneficial to constraining the accuracy of the method or calibrating it for operational use, it is nevertheless a powerful tool in its present form for lake-to-lake and regional runoff inter-comparisons.

  6. Survey of Archaeal Diversity in Sediments of Qinghai Lake, China and Implications for Paleoclimate Change

    Science.gov (United States)

    Ye, Q.; Jiang, H.; Ji, S.; Dong, H.; Zhang, C.

    2006-12-01

    Qinghai Lake, the largest inland saline lake in China, is located in the northeastern corner of Tibetan Plateau at an altitude of 3200 m above the sea level. Previous research suggests that sediments in Qinghai Lake may be a good recorder of changes in climate during the last 18,000 years. But it is not clear if microbial record can be used to help reconstruct paleoclimate. The goal of this study was to explore the relationship between archaeal microbial communities and paleoclimatic changes. A 5-m long sediment core was collected with a drilling rig and two subsamples from 0-10 cm and 345-355 cm depth intervals were used for this study. These two subsamples (corresponding to present and ~7 cal. Kyr BP, respectively) represent cold/arid and warm/wet conditions (Shen et al., 2004) . 16S archaeal rRNA gene and lipid biomarker analyses were performed on these two samples. The archaeal 16S rRNA gene fragments were PCR-amplified from extracted nucleic acids and cloned for sequence determination. A total of 90 clones were sequenced for the two samples studied. Rarefaction analysis indicated that the number of unique clones reached saturation. Phylogenetic analysis of both clone libraries revealed the presence of two major lineages, belonging to the Euryarchaeota and Crenarchaeota phyla. Sequences from different libraries formed distinct clusters in both phyla, and clonal sequences were not closely related to any known isolates. LIBSHUFF analysis displayed the significant dissimilarity of archaeal diversity between two studied samples. In addition, Crenarchaeotal biomarker (GDGT) was only detected in the top layer by lipid analyses.The crenarchaeotal abundance at the bottom sample may be below the detection limit and much lower than that of the top one. In summary, our results suggest that the composition and structure of archaeal community is significantly different under different climatic condition, and may affect the biological carbon cycling in this unique Qinghai

  7. Fine resolution AMS {sup 14}C chronology for Lunette-Lake sediment sequences, Lake Bolac, Victoria

    Energy Technology Data Exchange (ETDEWEB)

    Cook, E. [Monash University, Clayton, VIC (Australia). Centre for Palynology and Palaeoecology, Department of Geography and Environmental Science

    1998-12-31

    This study aims to provide a fine-resolution chronology for lake sediment records from Lakes Bolac and Turangmoroke, located within the drier part of the Western Plains, Victoria. These lakes are expected to be sensitive to subtle climate and vegetation variability and have long been recognised as archaeologically rich, bearing stone tools, hearth and other cultural materials dated to the late Pleistocene (Horton, 1984; former Victorian Aboriginal Survey, unpublished data). Fine-resolution chronological control has rarely been attempted in this sedimentary and (semi-arid) climatic context owing to the paucity of material available for conventional {sup 14}C dating. However, pollen and microscopic charcoal in the lake sediments at Bolac and Turangmoroke are suitable for AMS age determination with the most important sedimentary section well within the range of {sup 14}C making them ideal records for such a study. Recent dating results, which have substantially increased chronostratigraphic interpretation of concurrent palaeoecological and sedimentological work in progress, are presented

  8. Indoor radon survey in dwellings of nine cities in the Eastern and the Western provinces of Saudi Arabia.

    Science.gov (United States)

    Abu-Jarad, F; Fazal-ur-Rehman; Al-Jarallah, M I; Al-Shukri, A

    2003-01-01

    The results of a first phase of an indoor radon survey in a total of 1610 dwellings distributed in nine cities of the Eastern and the Western provinces of Saudi Arabia are presented. The objective of this radon survey was to obtain representative indoor radon data for seven cities in the Eastern province. Khafji, Hafr Al-Batin, Abqaiq, Qatif, Al-Ahsa, Dammam and Khobar and to compare this with two cities in the Western province, Madina and Taif. So far, detailed radon data is not available for Saudi Arabia: therefore, this radon survey provides a base line for Saudi Arabia in the Radon World Atlas. On average, 200 indoor radon dosemeters were distributed in each city and placed for a period of one year starting from May 2001 to May 2002. The total number of collected dosemeters was 847. A total of 724 houses and 98 schools were covered in this survey. The results of the survey in the cities showed that the overall minimum, maximum and average radon concentrations were 1, 137 and 22 Bq m(-3), respectively. Geometric mean and geometric standard deviations of the radon distribution were found to be 18 and 1.92, respectively. In one of the dwellings in Qatif city, radon concentration, measured by a passive system and then confirmed by an active system, was found to be 535 +/- 23 and 523 +/- 22 Bq m(-3), respectively. The result of a radon survey in 98 schools showed that the minimum, maximum and average radon concentrations were 1, 70 and 19 Bq m(-3), respectively. The average radon concentration for each city was also determined. The lowest average radon concentration (8 Bq m(-3)) was found in Al-Ahsa while the highest average concentration (40 Bq m(-3)) was found in Khafji.

  9. Indoor radon survey in dwellings of nine cities in the eastern and western provinces of Saudi Arabia

    Energy Technology Data Exchange (ETDEWEB)

    Abu-Jarad, F.; Fazal-ur-Rehman; Al-Jarallah, M.I.; Al-Shukri, A

    2003-07-01

    The results of a first phase of an indoor survey in a total of 1610 dwellings distributed in nine cities of the Eastern and the Western provinces of Saudi Arabia are presented. The objective of this radon survey was to obtain representative indoor radon data for seven cities in the Eastern province, Khafji, Hafr Al-Batin, Abqaiq, Qatif, Al-Ahsa, Dammam and Khobar and to compare this with two cities in the Western province, Madina and Taif. So far, detailed radon data is not available for Saudi Arabia; therefore, this radon survey provides a base line for Saudi Arabia in the Radon World Atlas. On average, 200 indoor radon dosemeters were distributed in each city and placed for a period of one year starting from May 2001 to May 2002. The total number of collected dosemeters was 847. A total of 724 houses and 98 schools were covered in this survey. The results of the survey in the cities showed that the overall minimum, maximum and average radon concentrations were 1, 137 and 22 Bq m {sup -3}, respectively. Geometric mean and geometric standard deviations of the radon distribution were found to be 18 and 1.92, respectively. In one of the dwellings in Qatif city, radon concentration, measured by a passive system and then confirmed by an active system, was found to be 535 {+-} 23 and 523 {+-} 22 Bq m {sup -3}, respectively. The result of a radon survey in 98 schools showed that the minimum, maximum and average radon concentrations were 1, 70 and 19 Bq m{sup -3}, respectively. The average radon concentration for each city was also determined. The lowest average radon concentration (8 Bq m{sup -3}) was found in Al-Ahsa while the highest average concentration (40 Bq m {sup -3}) was found in Khafji. (author)

  10. Reasons for the outbreak of microphytoplankton productivity in the late Oligocene Turtas Lake-Sea, Western Siberia

    Science.gov (United States)

    Kuzmina, O. B.; Kuzmin, D. V.; Shurygin, B. N.

    2017-06-01

    Palynological (dinocysts) and geochemical data were compared for the first time for Paleogene sediments of borehole no. 8 (settlement of Russkaya Polyana, Omsk oblast). The layers with a concentrated amount of dinocysts of the genus Pseudokomewuia (20.5% of the palynocomplex) are characterized by higher contents of Fe, P, Ti, Nb, Ta, and W. The microphytoplankton bloom (an analog of the present-day red tides) in the late Oligocene Turtas Lake-Sea was probably caused by a greater contribution of nutrient substances from the continent during the transgression of this basin. Comparative analysis of the geochemical features of marine and continental Paleogene sediments from borehole no. 8 showed that the Turtas basin was either freshwater or had brackish water.

  11. Willapa NWR: Initial Survey Instructions for Western Snowy Plover Monitoring - State and Rangewide Breeding and Winter Window Surveys

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Inventories, monitoring, research, assessments, and studies are essential to high-quality habitat and population management. Conducting population surveys for the...

  12. AFSC/NMML: Killer whale surveys in the Aleutian Islands, Bering Sea, and western and central Gulf of Alaska, 2001 - 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is a compilation of line-transect data collected on surveys in the Aleutian Islands, Bering Sea, and western and central Gulf of Alaska, 2001 - 2010....

  13. The sero-epidemiology of Rift Valley fever in people in the Lake Victoria Basin of western Kenya.

    Directory of Open Access Journals (Sweden)

    Elizabeth Anne Jessie Cook

    2017-07-01

    Full Text Available Rift Valley fever virus (RVFV is a zoonotic arbovirus affecting livestock and people. This study was conducted in western Kenya where RVFV outbreaks have not previously been reported. The aims were to document the seroprevalence and risk factors for RVFV antibodies in a community-based sample from western Kenya and compare this with slaughterhouse workers in the same region who are considered a high-risk group for RVFV exposure. The study was conducted in western Kenya between July 2010 and November 2012. Individuals were recruited from randomly selected homesteads and a census of slaughterhouses. Structured questionnaire tools were used to collect information on demographic data, health, and risk factors for zoonotic disease exposure. Indirect ELISA on serum samples determined seropositivity to RVFV. Risk factor analysis for RVFV seropositivity was conducted using multi-level logistic regression. A total of 1861 individuals were sampled in 384 homesteads. The seroprevalence of RVFV in the community was 0.8% (95% CI 0.5-1.3. The variables significantly associated with RVFV seropositivity in the community were increasing age (OR 1.2; 95% CI 1.1-1.4, p<0.001, and slaughtering cattle at the homestead (OR 3.3; 95% CI 1.0-10.5, p = 0.047. A total of 553 slaughterhouse workers were sampled in 84 ruminant slaughterhouses. The seroprevalence of RVFV in slaughterhouse workers was 2.5% (95% CI 1.5-4.2. Being the slaughterman, the person who cuts the animal's throat (OR 3.5; 95% CI 1.0-12.1, p = 0.047, was significantly associated with RVFV seropositivity. This study investigated and compared the epidemiology of RVFV between community members and slaughterhouse workers in western Kenya. The data demonstrate that slaughtering animals is a risk factor for RVFV seropositivity and that slaughterhouse workers are a high-risk group for RVFV seropositivity in this environment. These risk factors have been previously reported in other studies providing further

  14. Presence of Potential Toxin-Producing Cyanobacteria in an Oligo-Mesotrophic Lake in Baltic Lake District, Germany: An Ecological, Genetic and Toxicological Survey

    Directory of Open Access Journals (Sweden)

    Pawan K. Dadheech

    2014-09-01

    Full Text Available Massive developments of potentially toxic cyanobacteria in Lake Stechlin, an oligo-mesotrophic lake in the Baltic Lake District of Germany raised concerns about toxic contamination of these important ecosystems. Field samples in the phase of mass developments of cyanobacteria were used for genetic and toxicological analyses. Microcystins and microcystin genes were detected in field samples of the lake for the first time. However, the toxins were not produced by the dominant taxa (Dolichospermum circinale and Aphanizomenon flos-aquae but by taxa, which were present only in low biomass in the samples (Microcystis cf. aeruginosa and Planktothrix rubescens. The phytoplankton successions during the study period revealed an increase of cyanobacterial populations. The findings contribute to the changes that have been investigated in Lake Stechlin since the mid-1990s. The possible reasons behind these developments may be climate change, special weather conditions and an increased nutrient pool.

  15. Presence of potential toxin-producing cyanobacteria in an oligo-mesotrophic lake in Baltic Lake District, Germany: an ecological, genetic and toxicological survey.

    Science.gov (United States)

    Dadheech, Pawan K; Selmeczy, Géza B; Vasas, Gábor; Padisák, Judit; Arp, Wolfgang; Tapolczai, Kálmán; Casper, Peter; Krienitz, Lothar

    2014-09-29

    Massive developments of potentially toxic cyanobacteria in Lake Stechlin, an oligo-mesotrophic lake in the Baltic Lake District of Germany raised concerns about toxic contamination of these important ecosystems. Field samples in the phase of mass developments of cyanobacteria were used for genetic and toxicological analyses. Microcystins and microcystin genes were detected in field samples of the lake for the first time. However, the toxins were not produced by the dominant taxa (Dolichospermum circinale and Aphanizomenon flos-aquae) but by taxa, which were present only in low biomass in the samples (Microcystis cf. aeruginosa and Planktothrix rubescens). The phytoplankton successions during the study period revealed an increase of cyanobacterial populations. The findings contribute to the changes that have been investigated in Lake Stechlin since the mid-1990s. The possible reasons behind these developments may be climate change, special weather conditions and an increased nutrient pool.

  16. The role of the U.S. Geological Survey in Lake Michigan Diversion Accounting in Illinois, 1984-2010

    Science.gov (United States)

    Johnson, Kevin K.; Duncker, James J.; Jackson, P. Ryan

    2012-01-01

    The State of Illinois' annual withdrawl from Lake Michigan is limited by a U.S. Supreme Court decree. The U.S. Geological Survey (USGS) is responsible for monitoring flows in the Chicago area waterway system (CAWS) as part of the Lake Michigan Diversion Accounting (LMDA) overseen by the U.S. Army Corps of Engineers, Chicago District. Every five years, the USGS streamgage practices in the CAWS are reviewed by a committee of practicing engineers and academics to ensure that the best engineering practices are implemented in accordance with the U.S. Supreme Court decree and as part of LMDA. This report provides a perspective on the role of the USGS in LMDA from 1984 to 2010 including the responses to the review committees. Six technical review committees have been convened by the U.S. Corps of Engineers to evaluate the key components of LMDA especially the USGS streamgages within the CAWS. Any changes in streamgaging practices at CAWS gaging stations require detailed analysis to ensure the change will not adversely affect the ability of the USGS to accurately monitor flows.

  17. Macroinvertebrates as indicators of fish absence in naturally fishless lakes

    Science.gov (United States)

    Schilling, Emily Gaenzle; Loftin, C.S.; Huryn, Alexander D.

    2009-01-01

    1. Little is known about native communities in naturally fishless lakes in eastern North America, a region where fish stocking has led to a decline in these habitats. 2. Our study objectives were to: (i) characterise and compare macroinvertebrate communities in fishless lakes found in two biophysical regions of Maine (U.S.A.): kettle lakes in the eastern lowlands and foothills and headwater lakes in the central and western mountains; (ii) identify unique attributes of fishless lake macroinvertebrate communities compared to lakes with fish and (iii) develop a method to efficiently identify fishless lakes when thorough fish surveys are not possible. 3. We quantified macroinvertebrate community structure in the two physiographic fishless lake types (n = 8 kettle lakes; n = 8 headwater lakes) with submerged light traps and sweep nets. We also compared fishless lake macroinvertebrate communities to those in fish-containing lakes (n = 18) of similar size, location and maximum depth. We used non-metric multidimensional scaling to assess differences in community structure and t-tests for taxon-specific comparisons between lakes. 4. Few differences in macroinvertebrate communities between the two physiographic fishless lake types were apparent. Fishless and fish-containing lakes had numerous differences in macroinvertebrate community structure, abundance, taxonomic composition and species richness. Fish presence or absence was a stronger determinant of community structure in our study than differences in physical conditions relating to lake origin and physiography. 5. Communities in fishless lakes were more speciose and abundant than in fish-containing lakes, especially taxa that are large, active and free-swimming. Families differing in abundance and taxonomic composition included Notonectidae, Corixidae, Gyrinidae, Dytiscidae, Aeshnidae, Libellulidae and Chaoboridae. 6. We identified six taxa unique to fishless lakes that are robust indicators of fish absence: Graphoderus

  18. Controls of dissolved organic matter quality: Evidence from a large-scale boreal lake survey

    DEFF Research Database (Denmark)

    Kothawala, D.N.; Stedmon, Colin; Müller, R.A.

    2014-01-01

    characteristics of PARAFAC components based on emission wavelength could ease future interpretation of fluorescence spectra. An important secondary influence on DOM quality was mean annual temperature, which ranged between -6.2 and +7.5 °C. These results suggest that DOM reactivity depends more heavily...... fluorescence spectroscopy to explore DOM quality from 560 lakes distributed across Sweden and encompassed a wide climatic gradient typical of the boreal ecozone. Six fluorescence components were identified using parallel factor analysis (PARAFAC). The intensity and relative abundance of these components were...

  19. Monitoring Change in Great Salt Lake

    Science.gov (United States)

    Naftz, David; Angeroth, Cory; Freeman, Michael; Rowland, Ryan; Carling, Gregory

    2013-08-01

    Great Salt Lake is the largest hypersaline lake in the Western Hemisphere and the fourth largest terminal lake in the world (Figure 1). The open water and adjacent wetlands of the Great Salt Lake ecosystem support millions of migratory waterfowl and shorebirds from throughout the Western Hemisphere [Aldrich and Paul, 2002]. In addition, the area is of important economic value: Brine shrimp (Artemia franciscana) residing in Great Salt Lake support an aquaculture shrimp cyst industry with annual revenues as high as $60 million.

  20. Survey of the Occurrence and Human Infective Potential of Giardia duodenalis and Cryptosporidium spp. in Wastewater and Different Surface Water Sources of Western Romania.

    Science.gov (United States)

    Imre, Kálmán; Morar, Adriana; Ilie, Marius S; Plutzer, Judit; Imre, Mirela; Emil, Tîrziu; Herbei, Mihai V; Dărăbuș, Gheorghe

    2017-10-01

    From the group of parasitic protozoa, Giardia and Cryptosporidium are the most common pathogens spread in surface water sources, representing a continuous threat to public health and water authorities. The aim of this survey was to assess the occurrence and human infective potential of these pathogens in treated wastewaters and different surface water sources. A total of 76 western Romanian water bodies in four counties (Arad, Bihor, Caraș-Severin and Timiș) were investigated, including the effluents of wastewater treatment plants (n = 11) and brooks (n = 19), irrigation channels (n = 8), lakes (n = 16), and ponds (n = 22). Water samples were collected through polyester microfiber filtration. Giardia cysts and Cryptosporidium oocysts were isolated using immunomagnetic separation, according to the US EPA 1623 method, followed by their identification and counting by immunofluorescence (IF) microscopy. All samples were screened through PCR-based techniques targeting the gdh gene for Giardia spp. and the 18S rRNA gene for Cryptosporidium spp., followed by sequencing of the positive results. Cryptosporidium-positive samples were subtyped based on sequence analysis of the GP60 gene. Giardia spp. was found in all tested water types with a cumulative detection rate of 90.1% in wastewaters, 26.3% in brooks, 37.5% in irrigation channels, 31.2% in lakes, and 36.4% in ponds. Except for ponds, all monitored water bodies harbored the Giardia duodenalis AII subassemblage with human infective potential. In addition, the ruminant origin assemblage E was widely distributed, and the domestic/wild canid-specific assemblage D was also recorded in a pond. Three (27.3%) wastewater samples were Cryptosporidium positive, and the identified species was the zoonotic Cryptosporidium parvum, with IIaA15G2R1 (n = 2) and IIdA18G1 subtypes. The results highlight that this threat to the public health must be brought to the attention of epidemiologists, health officials

  1. A Survey of Associate of Arts and Associate of Science Degree Programs in 13 Western States.

    Science.gov (United States)

    Bekker, Gerald

    The Associate of Arts and Associate of Science degree programs offered by selected colleges and universities in 13 western states were examined to determine relevant information regarding the composition of the degrees offered. The study specifically concerned: the purpose of the degree, the title assigned to the degree, the length of time…

  2. Student Performance and Family Socioeconomic Status: Results from a Survey of Compulsory Education in Western China

    Science.gov (United States)

    Liu, Xiaofei; Lu, Ke

    2008-01-01

    This study used fifteen-year-old ninth-grade students from rural areas of five provinces in western China as samples to carry out research on the relationship between the socioeconomic status of Chinese families and student academic performance. Based on parents' educational background, occupation, family economic conditions, and other factors,…

  3. Depression and inflammatory arthritis are associated in both Western and Non-Western countries: Findings from the World Health Survey 2002.

    Science.gov (United States)

    Apfelbacher, Christian; Brandstetter, Susanne; Herr, Raphael; Ehrenstein, Boris; Loerbroks, Adrian

    2017-01-01

    Epidemiological studies have linked arthritis to depression. However, it remains unclear to what degree the association between arthritis and depression extends to low income countries and whether it can be replicated for inflammatory arthritis (IA). We aimed to address these knowledge gaps based on a large multi-national sample. Cross-sectional data was drawn from the 2002 World Health Survey. IA was defined as reports of either a diagnosis or treatment of arthritis and morning stiffness for >30min. Self-reported depression was defined as positive if participants reported its prior diagnosis or treatment or if they were classified as suffering from a major depressive episode by a seven-item screening instrument. Multivariable logistic regression analysis was used to estimate odds ratios (ORs) and 95% confidence intervals (CI) for the entire sample and stratified by sex and continent. The odds of IA was 2.6-fold increased in those with depression compared to those without (OR=2.64, 95% CI 2.18-3.21) in the entire sample. This association was observed in both men (OR=3.06, 95% CI 2.19-4.27) and women (OR=2.50, 95% CI 1.95-3.21). Similar associations were found on the continent level, but were generally stronger for the Americas and Asia compared to Africa and Europe. Although our definition of IA was limited by the use of self-reported morning stiffness, this study suggests that there is a positive association between inflammatory arthritis and depression in Western and Non-Western countries, suggesting that this relationship represents a universal phenomenon. Copyright © 2016. Published by Elsevier Inc.

  4. Sedimentary signature of Hurricane Isaac in a Taxodium swamp on the western margin of Lake Pontchartrain, Louisiana, USA

    Directory of Open Access Journals (Sweden)

    K.-B. Liu

    2015-03-01

    Full Text Available Compositional and geochemical profiles were established for a 59-cm sediment core extracted from a small pothole pond in a Taxodium (bald cypress swamp 830 m inland from Lake Pontchartrain in south-eastern Louisiana, USA. The core consists of a top organic unit (peat to clayey peat from 0–29 cm above a bottom clay unit at 30–59 cm depth. Four distinct zones, marked by gradual changes in organic content and elemental concentrations, occur in the clay unit. These changes probably reflect two cycles of slowly changing water depths. Hurricane Isaac’s signature, a brown clay band at 3–5 cm, is identified based on the stratigraphic and compositional correspondence with the storm’s event layer, documented from nearby sites. Sedimentary and geochemical similarities between this material and clastic bands at 15–19 and 23–25 cm identify those two intervals as potentially representing earlier floods. The Cl/Br ratio presents a potentially useful method for distinguishing fluvial and marine flooding.

  5. Morphostructural record of iron deposits in paleosols, cretaceous Nubia Sandstone of Lake Naser basin, Egypt, Western Desert, Egypt

    Directory of Open Access Journals (Sweden)

    S.M. Salem

    2013-06-01

    Full Text Available The use of processed Landsat ETM + images and the application of geomorphotectonic concepts supplemented by extensive geological field work enabled the effective record of iron occurrences in the area located to the west of Lake Nasser. Three clearly newly differentiated landforms are evaluated for the possible presence of iron occurrences. Each landform is controlled by a specific tectonic environment and includes one of the three stratigraphic formations hosting iron deposits in the area. These landforms are: Area 1 (Kurkur landform, including plunging anticlines and domes affecting the Abu Aggag Formation. This formation is unconformably overlain by horizontal sandstone beds belonging to the Temsah Formation. The unconformity surface includes paleosols rich in limonite, crystallized gypsum in the form of roses and clay minerals. Area 2 (Tushka landform extends to the south of the Allaqi fault. The area includes yardangs carved in horizontal sandstone beds interstratified with some hematite bed, in addition to several fragments of hematite and magnetite as wadi deposits and desert varnish. Area 3 (Abu Simbel landform includes conical hills constituted by flattened horizontal beds belonging to the El Burg Formation. Each hill is capped by thick hematite/magnetite beds extending from Tushka to the border with Sudan. The Nubia Sandstone, here, includes three formations, namely: the Abu Aggag, Temsah, and Um Baramil.

  6. Occurrence of Porodaedalea pini (Brot.: Fr. Murr. in pine forests of the lake district in south-western Turkey

    Directory of Open Access Journals (Sweden)

    A. Lehtijärvi

    2007-12-01

    Full Text Available The occurrence of basidiocarps of the white rot fungus Porodaedalea (Phellinus pini on Pinus nigra subsp. pallasiana and P. brutia was investigated in six stands, covering a total land area of some 650 hectares, in Isparta province of the Lake District in Turkey. The height above ground of the lowermost P. pini basidiocarp was measured on each trunk. Basidiocarps of P. pini were found on thirty-eight trees, 32 P. nigra subsp. pallasiana (84.2% of the total and six P. brutia (15.8%. The breast-height diameter of P. nigra individuals with P. pini ranged from 41 to 188 cm (average 77.7 cm and that of P. brutia with P. pini from 68 to 96 cm (average 76.4 cm. Basidiocarps were mostly found on the lower part of the trunks of old trees. In addition to pathological aspects, the ecological role of the fungus in old-growth pine forests is discussed in relation to nature conservancy and biodiversity.

  7. Great lakes prey fish populations: a cross-basin overview of status and trends based on bottom trawl surveys, 1978-2012

    Science.gov (United States)

    Gorman, Owen T.

    2012-01-01

    The assessment of prey fish stocks in the Great Lakes have been conducted annually with bottom trawls since the 1970s by the Great Lakes Science Center, sometimes assisted by partner agencies. These stock assessments provide data on the status and trends of prey fish that are consumed by important commercial and recreational fishes. Although all these annual surveys are conducted using bottom trawls, they differ among the lakes in the proportion of the lake covered, seasonal timing, bottom trawl gear used, and the manner in which the trawl is towed (across or along bottom contours). Because each assessment is unique in one or more important aspects, direct comparison of prey fish catches among lakes is not straightforward. However, all of the assessments produce indices of abundance or biomass that can be standardized to facilitate comparisons of status and trends across all the Great Lakes. In this report, population indices were standardized to the highest value for a time series within each lake for the following principal prey species: cisco (Coregonus artedi), bloater (C. hoyi), rainbow smelt (Osmerus mordax), and alewife (Alosa pseudoharengus). Indices were also provided for round goby (Neogobius melanostomus), an invasive fish that has proliferated throughout the basin over the past 18 years. These standardized indices represent the best available long-term indices of relative abundance for these fishes across all of the Great Lakes. In this report, standardized indices are presented in graphical form along with synopses to provide a short, informal cross-basin summary of the status and trends of principal prey fishes. In keeping with this intent, tables, references, and a detailed discussion were omitted.

  8. Optical dating of fluvio-deltaic clastic lake-fill sediments - A feasibility study in the Holocene Rhine delta (western Netherlands)

    NARCIS (Netherlands)

    Wallinga, J.; Bos, I.J.

    2010-01-01

    We test the applicability of quartz optically stimulated luminescence (OSL) dating on clastic lake sediments to investigate whether this dating method can be applied to study the timing and rate of deposition in Holocene fluvio-deltaic lakes. Our study concerns the filling of a lake by the

  9. Seroepidemiological investigation of foot-and-mouth disease virus serotypes in cattle around Lake Mburo National Park in South-Western Uganda

    DEFF Research Database (Denmark)

    Mwiine, Frank Norbert; Ayebazibwe, Chrisostom; Alexandersen, Søren

    2010-01-01

    Foot-and-mouth disease (FMD) outbreaks in cattle occur annually in Uganda. In this study the authors investigated antibodies against FMD virus (FMDV) in cattle in surrounding areas of Lake Mburo National Park in South-western Uganda. Two hundred and eleven serum samples from 23 cattle herds were...... in SPBEs were identified in 61% (19/31), 33% (5/15), 6%7 (20/30), 37% (10/27) and 12% (4/33) of the investigated samples for serotypes O, A, SAT 1, SAT 2 and SAT 3, respectively. This study indicates that most of the FMD outbreaks in the cattle herds in the investigated area were probably caused by FMDV...... serotype O, A and/ or SAT-serotype(s). It also shows that the usage of non-purified, multivalent vaccines in Uganda obscures the serological diagnosis of FMDV outbreaks, and that the sampling strategy needs to be improved. Finally, it emphasizes the importance of isolation and characterization of FMD...

  10. High-resolution digital elevation dataset for Crater Lake National Park and vicinity, Oregon, based on LiDAR survey of August-September 2010 and bathymetric survey of July 2000

    Science.gov (United States)

    Robinson, Joel E.

    2012-01-01

    Crater Lake partially fills the caldera that formed approximately 7,700 years ago during the eruption of a 12,000-foot volcano known as Mount Mazama. The caldera-forming or climactic eruption of Mount Mazama devastated the surrounding landscape, left a thick deposit of pumice and ash in adjacent valleys, and spread a blanket of volcanic ash as far away as southern Canada. Because the Crater Lake region is potentially volcanically active, knowledge of past events is important to understanding hazards from future eruptions. Similarly, because the area is seismically active, documenting and evaluating geologic faults is critical to assessing hazards from earthquakes. As part of the American Recovery and Reinvestment Act (ARRA) of 2009, the U.S. Geological Survey was awarded funding for high-precision airborne LiDAR (Light Detection And Ranging) data collection at several volcanoes in the Cascade Range through the Oregon LiDAR Consortium, administered by the Oregon Department of Geology and Mineral Industries (DOGAMI). The Oregon LiDAR Consortium contracted with Watershed Sciences, Inc., to conduct the data collection surveys. Collaborating agencies participating with the Oregon LiDAR Consortium for data collection in the Crater Lake region include Crater Lake National Park (National Park Service) and the Federal Highway Administration. In the immediate vicinity of Crater Lake National Park, 798 square kilometers of LiDAR data were collected, providing a digital elevation dataset of the ground surface beneath forest cover with an average resolution of 1.6 laser returns/m2 and both vertical and horizontal accuracies of ±5 cm. The LiDAR data were mosaicked in this report with bathymetry of the lake floor of Crater Lake, collected in 2000 using high-resolution multibeam sonar in a collaborative effort between the U.S. Geological Survey, Crater Lake National Park, and the Center for Coastal and Ocean Mapping at the University of New Hampshire. The bathymetric survey

  11. Combined use of frequency-domain electromagnetic and electrical resistivity surveys to delineate near-lake groundwater flow in the semi-arid Nebraska Sand Hills, USA

    Science.gov (United States)

    Ong, John B.; Lane, John W.; Zlotnik, Vitaly A.; Halihan, Todd; White, Eric A.

    2010-09-01

    A frequency-domain electromagnetic (FDEM) survey can be used to select locations for the more quantitative and labor-intensive electrical resistivity surveys. The FDEM survey rapidly characterized the groundwater-flow directions and configured the saline plumes caused by evaporation from several groundwater-dominated lakes in the Nebraska Sand Hills, USA. The FDEM instrument was mounted on a fiberglass cart and towed by an all-terrain vehicle, covering about 25 km/day. Around the saline lakes, areas with high electrical conductivity are consistent with the regional and local groundwater flow directions. The efficacy of this geophysical approach is attributed to: the high contrast in electrical conductivity between various groundwater zones; the shallow location of the saline zones; minimal cultural interference; and relative homogeneity of the aquifer materials.

  12. Climate Change and Infectious Disease Risk in Western Europe: A Survey of Dutch Expert Opinion on Adaptation Responses and Actors.

    Science.gov (United States)

    Akin, Su-Mia; Martens, Pim; Huynen, Maud M T E

    2015-08-18

    There is growing evidence of climate change affecting infectious disease risk in Western Europe. The call for effective adaptation to this challenge becomes increasingly stronger. This paper presents the results of a survey exploring Dutch expert perspectives on adaptation responses to climate change impacts on infectious disease risk in Western Europe. Additionally, the survey explores the expert sample's prioritization of mitigation and adaptation, and expert views on the willingness and capacity of relevant actors to respond to climate change. An integrated view on the causation of infectious disease risk is employed, including multiple (climatic and non-climatic) factors. The results show that the experts consider some adaptation responses as relatively more cost-effective, like fostering interagency and community partnerships, or beneficial to health, such as outbreak investigation and response. Expert opinions converge and diverge for different adaptation responses. Regarding the prioritization of mitigation and adaptation responses expert perspectives converge towards a 50/50 budgetary allocation. The experts consider the national government/health authority as the most capable actor to respond to climate change-induced infectious disease risk. Divergence and consensus among expert opinions can influence adaptation policy processes. Further research is necessary to uncover prevailing expert perspectives and their roots, and compare these.

  13. A pesticide monitoring survey in rivers and lakes of northern Greece and its human and ecotoxicological risk assessment.

    Science.gov (United States)

    Papadakis, Emmaluel N; Vryzas, Zisis; Kotopoulou, Athena; Kintzikoglou, Katerina; Makris, Konstantinos C; Papadopoulou-Mourkidou, Euphemia

    2015-06-01

    A pesticide monitoring study covering the main rivers and lakes of Northern Greece (Macedonia, Thrace and Thessaly) was undertaken. A total of 416 samples were collected over a 1.5-year sampling period (September 1999- February 2001) from six rivers and ten lakes. The water samples were analyzed with an off-line solid phase extraction technique coupled with a gas chromatography ion trap mass spectrometer using an analytical method for 147 pesticides and their metabolites, including organochlorines, organophosphates, triazines, chloroacetanilides, pyrethroids, carbamates, phthalimides and other pesticides (herbicides, insecticides and fungicides). Based on the pesticide survey results, a human health carcinogenic and non-carcinogenic risk assessment was conducted for adults and children. Ecotoxicological risk assessment was also conducted using default endpoint values and the risk quotient method. Results showed that the herbicides metolachlor, prometryn, alachlor and molinate, were the most frequently detected pesticides (29%, 12.5%, 12.5% and 10%, respectively). They also exhibited the highest concentration values, often exceeding 1 μg/L. Chlorpyrifos ethyl was the most frequently detected insecticide (7%). Seasonal variations in measured pesticide concentrations were observed in all rivers and lakes. The highest concentrations were recorded during May-June period, right after pesticide application. Concentrations of six pesticides were above the maximum allowable limit of 0.1 μg/L set for drinking water. Alachlor, atrazine and a-HCH showed unacceptable carcinogenic risk estimates (4.5E-06, 4.6E-06 and 1.3E-04, respectively). Annual average concentrations of chlorpyriphos ethyl (0.031 μg L), dicofol (0.01 μg/L), dieldrin (0.02 μg/L) and endosulfan a (0.065 μg/L) exceeded the EU environmental quality standards. The risk quotient estimates for the insecticides chorpyrifos ethyl, diazinon and parathion methyl and herbicide prometryn were above acceptable risk

  14. A survey of Western Australian sheep, cattle and kangaroos to determine the prevalence of Coxiella burnetii.

    Science.gov (United States)

    Banazis, Michael Janis; Bestall, Abbey Simone; Reid, Simon Andrew; Fenwick, Stan Gordon

    2010-07-14

    The objective of this study was to investigate the prevalence of Coxiella burnetii in two domestic ruminant species (cattle and sheep) and the western grey kangaroo (Macropus fuliginosus) in Western Australia (WA). The IDEXX CHEKiT Q Fever ELISA and CFT were used to test sera from 50 sheep and 329 head of cattle for anti-C. burnetii antibodies and 343 kangaroo sera were tested using an indirect ELISA developed specifically for this study. Faecal or urine samples collected from the same animals were tested with two PCR assays to identify active shedding of C. burnetii in excreta. Only two of the 379 ruminant sera had detectable levels of anti-C. burnetii antibodies according to the ELISA while the CFT did not detect any positive samples. In contrast 115 of the 343 western grey kangaroo serum samples were positive when tested with the antibody-ELISA. The first qPCR assay, targeting the IS1111a element, identified 41 of 379 ruminant and 42 of 343 kangaroo DNA samples as positive for C. burnetii DNA. The second qPCR, targeting the JB153-3 gene, identified nine C. burnetii DNA-positive ruminant samples and six positive kangaroo samples. Sequence comparisons showed high degrees of identity with C. burnetii. Isolation of C. burnetii from faeces was also attempted but was not successful. From the results presented here it appears that domestic ruminants may not be the most significant reservoir of C. burnetii in WA and that kangaroos may pose a significant threat for zoonotic transfer of this pathogen. (c) 2009 Elsevier B.V. All rights reserved.

  15. From Odysseus to Robinson Crusoe: A Survey of Early Western Island Literature

    OpenAIRE

    Chet Van Duzer

    2006-01-01

    This paper examines the history and development of books about islands in Western culture. Islands are prominent in Homer’s Odyssey, and Plato’s island of Atlantis is perhaps the most famous mythical island of all time. The Greeks were the first to develop the island-book as such, but Roman writers showed much less interest in insular themes. The article traces the history of the immrama (medieval Irish accounts of mythical Atlantic island voyages), notes the importance of islands in Marco Po...

  16. Survey for the presence of Naegleria fowleri amebae in lake water used to cool reactors at a nuclear power generating plant.

    Science.gov (United States)

    Jamerson, Melissa; Remmers, Kenneth; Cabral, Guy; Marciano-Cabral, Francine

    2009-04-01

    Water from Lake Anna in Virginia, a lake that is used to cool reactors at a nuclear power plant and for recreational activities, was assessed for the presence of Naegleria fowleri, an ameba that causes primary amebic meningoencephalitis (PAM). This survey was undertaken because it has been reported that thermally enriched water fosters the propagation of N. fowleri and, hence, increases the risk of infection to humans. Of 16 sites sampled during the summer of 2007, nine were found to be positive for N. fowleri by a nested polymerase chain reaction assay. However, total ameba counts, inclusive of N. fowleri, never exceeded 12/50 mL of lake water at any site. No correlation was obtained between the conductivity, dissolved oxygen, temperature, and pH of water and presence of N. fowleri. To date, cases of PAM have not been reported from this thermally enriched lake. It is postulated that predation by other protozoa and invertebrates, disturbance of the water surface from recreational boating activities, or the presence of bacterial or fungal toxins, maintain the number N. fowleri at a low level in Lake Anna.

  17. Nutrition of the captive western lowland gorilla (Gorilla gorilla gorilla): a dietary survey.

    Science.gov (United States)

    Smith, B K; Remis, M J; Dierenfeld, E S

    2014-01-01

    The successful management of captive animals requires attention to multiple interconnected factors. One critical aspect of the daily life of a captive animal is the recommended and/or provisioned diet. This study focuses on the diets of zoo-housed gorillas. A national survey of diets among zoo-housed gorillas was conducted to examine diets being offered to captive gorillas in the United States and Canada. This survey serves as a follow-up to a 1995 dietary survey of zoo-housed gorillas and goes further to quantify nutritional profiles at responding institutions. Results are encouraging, as zoos have made clear improvements in dietary nutrient profiles offered over the past 15 years. However, we suggest that zoological and sanctuary institutions follow Gorilla Species Survival Plan (SSP) recommendations and work to continuously improve diets provided, which could improve gorillas' health and well-being. © 2014 Wiley Periodicals, Inc.

  18. Floristic Survey of Summer Aspect in Chosen China Clay Pits in Western Bohemia

    Directory of Open Access Journals (Sweden)

    Kamila Botková

    2016-01-01

    Full Text Available Five different china clay pits in the western part of the Czech Republic were explored and plant species were determined. These chosen pits were: Hájek-western part, Chlumčany, Horní Bříza, Otovice and Podlesí II. China clay pits with active excavation represent a specific environment concerning both physical and chemical characteristics. This article is presenting a list of the higher plants which were found within active excavation or former excavation areas. Species with a protection status according to the Czech legislation are presented in more detail. 189 different species have been found in total, including 2 species from category C4 – potentially vulnerable taxa, 6 species from category C3 – endangered taxa and 1 species from the C1 – critically threatened taxa from the Red List of Vascular Plants of the Czech Republic. 28 different species occurred at each of the five sites. Predominant species favour sandy substratum and bare surface.

  19. U.S. Geological Survey (USGS) Western Region: Seabirds Coastal and Ocean Science

    Science.gov (United States)

    Kinsinger, Anne E.

    2009-01-01

    From the cold, high Arctic area of Alaska to the warm, tropical Pacific area of Hawai'i, a diverse array of seabird species numbering in the millions of individuals live off the bounty of the Pacific Ocean. Many come to land only to nest and raise their young - these are species supremely adapted for life on the water, whether it be near the coast or hundreds of miles at sea. Those seabirds that reside in the North Pacific year-round are joined each summer by millions of migrant birds that leave the southern hemisphere in winter for better feeding conditions in the north. Seabirds in the Pacific remain one of the great wildlife spectacles on the earth. Yet, seabirds face a number of threats such as oil spills, introduction of predators to their nesting islands, and conflicts with fisheries. State and Federal agencies require increasingly sophisticated information on population dynamics, breeding biology, and feeding ecology to successfully manage these species and their ecosystems. Within the Western Region of the USGS, scientists from the Alaska Science Center (ASC), Western Ecological Research Center (WERC), and Pacific Islands Ecosystems Research Center are leading the way in conducting research on many of these little known species. Their aim is to improve our understanding of seabirds in the Pacific and to provide information to support informed management of the birds and their ecosystems.

  20. Equine peripheral dental caries: An epidemiological survey assessing prevalence and possible risk factors in Western Australian horses.

    Science.gov (United States)

    Jackson, K; Kelty, E; Tennant, M

    2018-01-01

    Peripheral dental caries is defined as macroscopic destruction of the calcified dental tissues and can cause considerable dental pathology and pain. It appears to occur at a high prevalence in Western Australian horses. At present, risk factors for the condition are poorly understood, making treatment and prevention difficult. To assess the prevalence of and potential risk factors for peripheral caries in Western Australian horses. Cross-sectional, epidemiological study. A survey of 500 Western Australian horses was administered in two sections. The first section was completed by the owner and referred to the horse's signalment, diet and husbandry conditions. The second section was completed by veterinarians and focused on the horse's oral health. A multivariable logistic regression model was used to assess risk factors associated with peripheral caries. Peripheral caries was present in 58.8% (95% confidence interval [CI] 54.5-63.1%) of surveyed horses. Breed was significantly associated with peripheral caries, with Warmbloods (odds ratio [OR] 0.44, 95% CI 0.24-0.82; P = 0.009) and Western breeds (OR 0.38, 95% CI 0.19-0.78; P = 0.008) being less likely to have peripheral caries than Thoroughbreds. Dietary risk factors included oaten hay (OR 2.90, 95% CI 1.87-4.53; Pcaries than horses without access to grazing (OR 0.31, 95% CI 0.15-0.66; P = 0.002), as were horses on groundwater compared with horses on rainwater (OR 3.35, 95% CI 1.65-6.78; P = 0.001), drinking water (OR 2.03, 95% CI 1.14-3.62; P = 0.016) or dam water (OR 3.53, 95% CI 1.08-11.53; P = 0.037). Peripheral caries was positively correlated with periodontal disease (OR 4.53, 95% CI 2.91-7.06; Pcaries. Management factors that may help to prevent or reduce peripheral caries include more access to quality pasture, use of groundwater, feeding on meadow hay and avoidance of oaten hay. © 2017 EVJ Ltd.

  1. Late quaternary geomorphology of the Great Salt Lake region, Utah, and other hydrographically closed basins in the western United States: A summary of observations

    Science.gov (United States)

    Currey, Donald R.

    1989-01-01

    Attributes of Quaternary lakes and lake basins which are often important in the environmental prehistory of semideserts are discussed. Basin-floor and basin-closure morphometry have set limits on paleolake sizes; lake morphometry and basin drainage patterns have influenced lacustrine processes; and water and sediment loads have influenced basin neotectonics. Information regarding inundated, runoff-producing, and extra-basin spatial domains is acquired directly from the paleolake record, including the littoral morphostratigraphic record, and indirectly by reconstruction. Increasingly detailed hypotheses regarding Lake Bonneville, the largest late Pleistocene paleolake in the Great Basin, are subjects for further testing and refinement. Oscillating transgression of Lake Bonneville began about 28,000 yr B.P.; the highest stage occurred about 15,000 yr B.P., and termination occurred abruptly about 13,000 yr B.P. A final resurgence of perennial lakes probably occurred in many subbasins of the Great Basin between 11,000 and 10,000 yr B.P., when the highest stage of Great Salt Lake (successor to Lake Bonneville) developed the Gilbert shoreline. The highest post-Gilbert stage of Great Salt Lake, which has been one of the few permanent lakes in the Great Basin during Holocene time, probably occurred between 3,000 and 2,000 yr B.P.

  2. Open / Unipede 1995 survey on uranium and enrichment requirements and supplies in Western Europe

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1995-12-31

    This report describes the current global situation with respect to uranium and enrichment supply and demand in Europe, as well as future prospects, based upon a survey conducted in mid-1995 by Unipede and Open among their member companies. The nuclear fuel cycle committees of Unipede and Open maintain an interest in all aspects of the nuclear fuel cycle from uranium procurement up to final disposal of radioactive waste. Regarding the front-end of the fuel cycle, the work within those committees currently concentrates of uranium and enrichment supply and demand in Europe, including the recycling of uranium and of plutonium recovered from reprocessing. For the past fifteen years, the nuclear fuel cycle committees of Unipede and Open have jointly conducted an annual survey among their members about uranium and enrichment requirements and supplies. The 1995 survey involved all nuclear electric utilities in Belgium, Finland, France, Germany, the Netherlands, Spain, Sweden, Switzerland and the United Kingdom. Exclusively electric utilities are surveyed, i.e. excluding national procurement organizations, traders, brokers, financial institutions, etc. The data obtained from the individual utilities in the same format, are aggregated and form the basis of the report. The quality of these data is guaranteed by the fact that the respondents are generally those people who are responsible for the day-to-day management of the nuclear fuel cycle in their company.

  3. A SURVEY OF LANDNET SITES FOCUSING ON TUZ GÖLÜ SALT LAKE, TURKEY

    Directory of Open Access Journals (Sweden)

    S. Z. Gürbüz

    2012-07-01

    Full Text Available Radiometric calibration is critical to ensure the accuracy, veracity, continuity and reliability of satellite data measured from multiple sensors and platforms, and is thus recognized as a key activity by all satellite operators. For imaging sensors, vicarious methods using natural targets (such as salt lakes, deserts, or flatlands that are well-characterized and preferably temporally and spatially stable as a reference are similarly well established. However, while selecting a target site, it is important that its quality and location are selected to minimize sources of uncertainty for any given sensor. To maximize the benefit from limited resources and minimize the impact on satellite operators, the Infrared Visible Optical Sensor (IVOS sub-group of Committee on Earth Observation Satellites (CEOS Working Group on Calibration and Validation (WGCV has selected a few, well-characterized, regularly instrumented target sites, which have since become known as LANDNET sites. Currently, there are eight LANDNET sites: 1 Dome C, Antarctica; 2 Dunhuang, China, Asia; 3 Lspec Frenchman Flat, NV, USA, North America; 4 Ivanpah, NV/CA, USA, North America; 5 La Crau, France, Europe; 6 Negev, Southern Israel, Asia; 7 Railroad Valley Playa, NV, USA, North America; 8 Tuz Gölü, Central Anatolia, Turkey, Asia. This work summarizes the key characteristics, and areas of application of each of the LANDNET sites, especially that of Tuz Gölü, to guide and inform researchers on site selection, and increase international awareness and collaboration in this field. Additionally, detailed information about the Tuz Gölü, Turkey test site is provided, including geographical characteristics, spatial uniformity qualities, and opportunities for international researchers to conduct experiments and measurements. Practical, technical, and logistical experience gained through the international field campaigns organized over the last few years at Tuz Gölü is also shared in

  4. From Odysseus to Robinson Crusoe: A Survey of Early Western Island Literature

    Directory of Open Access Journals (Sweden)

    Chet Van Duzer

    2006-05-01

    Full Text Available This paper examines the history and development of books about islands in Western culture. Islands are prominent in Homer’s Odyssey, and Plato’s island of Atlantis is perhaps the most famous mythical island of all time. The Greeks were the first to develop the island-book as such, but Roman writers showed much less interest in insular themes. The article traces the history of the immrama (medieval Irish accounts of mythical Atlantic island voyages, notes the importance of islands in Marco Polo and John of Mandeville, describes the rise of the isolario, or island-book illustrated with maps, and concludes with the emergence of the Robinsonade.

  5. CHAPHOLO: Paleolimnological Evaluation of Lake Chapala (Western Mexico) During the Past 10,000 Years (CONACYT CB2011, Grant 168685, In Progress). PHASE I: Drilling Campaign.

    Science.gov (United States)

    Zarate, P. F.; Dorfler, W.; Nelle, O.; Israde-Alcantara, I.

    2014-12-01

    Lake Chapala being the Mexican largest shallow (ca. 5 m) lake, of tectonic origin, is located in western Mexico. Based on magnetic profiles carried on by Alatorrre et al. (2007), the depocenter area, having an extension of ~ 10 km (E-W) x ~ 5 km (N-S), was delimited. The drilling campaign was carried out in April 2014, recovering a total of 51.50 m of sediment with a Usinger drilling machine (Ø 80 mm and 55 mm) and a Uwitec platform. To achieve efficient stratigraphic control at the site CHD (103° 02'W, 20° 15' N), 51.50 m of sediment were cored at three equidistant holes spread ca. 4 m: CHD-A (4.20 m), CHD-B (27.15 m) and CHD (20.15 m). The stratigraphic depth reached was 27.15 m. After recovery, the undisturbed sediment was extruded from iron tubes into PVC tubes and split longitudinally resulting one working half for laboratory work and the other as archive half. In total we obtained 103 "half tubes", that were protected with plastic film wrap and stored in plastic bags and keeping refrigerated at 4° C. The sediment collected is loose and its grain size is silty-clay, with the exception of volcanic material. The preliminary megascopic description of the sediment in CHD-A core based on color, presence of laminations, volcanic ash and black particles is as follows: COLOR. (0 m-4.15 m) gray-brown; (4.15 m -22.15 m) dark gray; (22.15 m -27.15 m) gray-brown. LAMINATION. (0m-11.15m) Incipient to defined; (11.15m-22.15m) Absent; (22.15m-23.15m) Incipient; (23.15m-27.15m) Absent. VOLCANIC ASH. (0m- 27.15m) Few horizons mm in thickness. From 26.52 m - 26.66 m a thin layer of 14 cm was observed. BLACK PARTICLES. (0m-27.15m) Presence at different concentration of black particles (cf. charcoal) DIATOM & POLLEN. (0m-10m) Central diatom (Surirella sp and Cyclotella sp); Pinus sp. The identification of different concentrations of charcoal is the opportunity to reconstruct the Holocene landscape dynamics in the watershed of Lake Chapala, regarding the fire history through

  6. Survey of Beaver-related Restoration Practices in Rangeland Streams of the Western USA

    Science.gov (United States)

    Pilliod, David S.; Rohde, Ashley T.; Charnley, Susan; Davee, Rachael R.; Dunham, Jason B.; Gosnell, Hannah; Grant, Gordon E.; Hausner, Mark B.; Huntington, Justin L.; Nash, Caroline

    2018-01-01

    Poor condition of many streams and concerns about future droughts in the arid and semi-arid western USA have motivated novel restoration strategies aimed at accelerating recovery and increasing water resources. Translocation of beavers into formerly occupied habitats, restoration activities encouraging beaver recolonization, and instream structures mimicking the effects of beaver dams are restoration alternatives that have recently gained popularity because of their potential socioeconomic and ecological benefits. However, beaver dams and dam-like structures also harbor a history of social conflict. Hence, we identified a need to assess the use of beaver-related restoration projects in western rangelands to increase awareness and accountability, and identify gaps in scientific knowledge. We inventoried 97 projects implemented by 32 organizations, most in the last 10 years. We found that beaver-related stream restoration projects undertaken mostly involved the relocation of nuisance beavers. The most common goal was to store water, either with beaver dams or artificial structures. Beavers were often moved without regard to genetics, disease, or potential conflicts with nearby landowners. Few projects included post-implementation monitoring or planned for longer term issues, such as what happens when beavers abandon a site or when beaver dams or structures breach. Human dimensions were rarely considered and water rights and other issues were mostly unresolved or addressed through ad-hoc agreements. We conclude that the practice and implementation of beaver-related restoration has outpaced research on its efficacy and best practices. Further scientific research is necessary, especially research that informs the establishment of clear guidelines for best practices.

  7. Lake Erie Fish Community Data

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Lake Erie Biological Station (LEBS), located in Sandusky, Ohio, is a field station of the USGS Great Lakes Science Center (GLSC). LEBS is the primary federal agency...

  8. 2002 Upper Texas Coast Lidar Point Data, Gulf of Mexico Shoreline in the Northeast 3.75-Minute Quadrant of the Lake Como 7.5-Minute Quadrangle: Post Fay Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains elevation data derived from a lidar survey approximately 300m wide of the Gulf of Mexico shoreline in the Northeast Lake Como...

  9. Bed Topography and Evidence of Possible new Subglacial Lakes Over the Region Vostok-Dome Concordia (East Antarctica) Inferred by Airborne Radar Survey

    Science.gov (United States)

    Tabacco, I. E.; Forieri, A.; Bianchi, C.; Zirizzotti, A.; Passerini, A.; Rémy, F.

    2002-05-01

    During the 1999 and 2001 Italian Antarctic Expeditions, extensive airborne radar surveys were carried out over the region Vostok-Dome C (about 6000 km of radar tracks were acquired). The radar data allowed to determine the ice thickness and the bedrock topography over the entire area; in addition, the analysis of the shape and the amplitude of the bottom reflections, permitted to identify 30 radar tracks as sub glacial "lake" mirrors. On account of the bed topography some important features were detected: (i) a deep trench into the Aurora Subglacial Basin, oriented approximately N-S at about 119o E, (that could be considered as the extension of the Peacock Subglacial Trenc) that divides the region into two sub-areas with different morphological aspect. The first one, located between the eastern ridge of Lake Vostok and the trench, is characterized by a bedrock that dips gently with a near constant gradient of about 4.2 m/km, without relevant local irregularities. The second one, located North-East of the trench towards Dome C, is characterized by a bedrock with a steep rise up and a complex morphology typical of mountain massif; (ii) a second trench, East of Dome C summit, N-S oriented at about 124.5o E. This trench seems to divide the Dome C massif by the Belgica Subglacial Highlands. Considering that the Dome C massif is surrounded North and North-East by the depressions of the Vincennes Subglacial Basin and of the Adventure Trench we could suggest that the Dome C mountains are morphologically like an isolated massif. The comparison of the surface topography, inferred by ERS-1 data, with the bed morphology, allowed to link and to correlate the surface slope anomalies with the main bed features. The "lake" radar tracks were analysed and compared with the surface slope anomalies and with the bed morphology. All the tracks are located over narrow and local anomalies of the bedrock like trough or catchment basin; 26 of the radar tracks lie over close and evident

  10. An ethnobotanical survey of medicinal plants in western part of central Taurus Mountains: Aladaglar (Nigde - Turkey).

    Science.gov (United States)

    Özdemir, Ebru; Alpınar, Kerim

    2015-05-26

    With this study, we aimed to document traditional uses of medicinal plants in the western part of Aladaglar/Nigde. This study was conducted between 2003 and 2005. The research area was in the western part of the Aladaglar mountains. The settlements in Aladaglar (5 towns and 10 villages) were visited during the field work. The plants collected by the help of medicinal plant users. The plants were identified and voucher specimens prepared. These voucher specimens were kept at the Herbarium of Istanbul University Faculty of Pharmacy (ISTE). We collected the information by means of semi-structured interviews with 170 informants (90 men and 80 women). In addition, the relative importance value of the species was determined and the informant consensus factor (FIC) was calculated for the medicinal plants researched in the study. According to the results of the identification, among 126 plants were used by the inhabitants and 110 species belonging to 40 families were used for medicinal purposes. Most of the medicinal plants used in Aladaglar/Nigde belong to the families Lamiaceae (25 species), Asteraceae (16 species), Apiaceae (7 species), Fabaceae (6 species) and Brassicaceae (5 species). The most commonly used plant species were Hypericum perforatumThymus sipyleus var. sipyleus, Rosa canina, Urtica dioica, Malva neglecta, Thymus leucotrichus, Salix alba, Mentha longifolia, Berberis crataegina, Juniperus oxycedrus, Viscum album subsp. abietis, Allium rotundum and Taraxacum stevenii. The most common preparations were infusion and decoction. The traditional medicinal plants have been mostly used for the treatment of cardiovascular diseases (86%), hemorrhoids (79%), urinary diseases (69%), diabetes (68%) and respiratory diseases (61%). The use of traditional medicine was still widespread among the inhabitants of Aladaglar mountains/Nigde region. Due to the lack of medical facilities in the villages of Aladaglar mountains, local people prefer herbal treatment rather than

  11. Integrated synoptic surveys of the hydrodynamics and water-quality distributions in two Lake Michigan rivermouth mixing zones using an autonomous underwater vehicle and a manned boat

    Science.gov (United States)

    Jackson, P. Ryan; Reneau, Paul C.

    2014-01-01

    The U.S. Geological Survey (USGS), in cooperation with the National Monitoring Network for U.S. Coastal Waters and Tributaries, launched a pilot project in 2010 to determine the value of integrated synoptic surveys of rivermouths using autonomous underwater vehicle technology in response to a call for rivermouth research, which includes study domains that envelop both the fluvial and lacustrine boundaries of the rivermouth mixing zone. The pilot project was implemented at two Lake Michigan rivermouths with largely different scales, hydrodynamics, and settings, but employing primarily the same survey techniques and methods. The Milwaukee River Estuary Area of Concern (AOC) survey included measurements in the lower 2 to 3 miles of the Milwaukee, Menomonee, and Kinnickinnic Rivers and inner and outer Milwaukee Harbor. This estuary is situated in downtown Milwaukee, Wisconsin, and is the most populated basin that flows directly into Lake Michigan. In contrast, the Manitowoc rivermouth has a relatively small harbor separating the rivermouth from Lake Michigan, and the Manitowoc River Watershed is primarily agricultural. Both the Milwaukee and Manitowoc rivermouths are unregulated and allow free exchange of water with Lake Michigan. This pilot study of the Milwaukee River Estuary and Manitowoc rivermouth using an autonomous underwater vehicle (AUV) paired with a manned survey boat resulted in high spatial and temporal resolution datasets of basic water-quality parameter distributions and hydrodynamics. The AUV performed well in these environments and was found primarily well-suited for harbor and nearshore surveys of three-dimensional water-quality distributions. Both case studies revealed that the use of a manned boat equipped with an acoustic Doppler current profiler (ADCP) and multiparameter sonde (and an optional flow-through water-quality sampling system) was the best option for riverine surveys. To ensure that the most accurate and highest resolution velocity data

  12. An Intensive Cultural Resources Survey at Tuttle Creek Lake Pottawatomie and Riley Counties.

    Science.gov (United States)

    1982-09-01

    reported by the 1970 survey to consist of a scatter over an area of approximately 9.1 by 7.3 m on a mud flat on the right bank of Fancy Creek. No diag...Crop Damages. The Contractor shall have right -of-entry on all property owned by the Government. Compensation for damages to crops planted on Government...Title (in progress): "The Early Horizon Olmec : "’ A Review of Their Style, Culture and Impact on *= Mesoamerica." B.A. Fordham University, 1972

  13. Feeding guilds of western Mediterranean demersal fish and crustaceans: an analysis based in a spring survey

    Directory of Open Access Journals (Sweden)

    Joan E. Cartes

    2002-06-01

    Full Text Available The MEDITS-99 sampling was performed along all the Iberian Peninsula coasts of the western Mediterranean (from the Alborán Sea to Cape Creus in a space-scale of 1000 Km N-S, at depths ranging between 27-790 m. Fish and decapod crustaceans were dominant in the megafaunal compartment sampled by trawling. Based on both the fish and the decapod crustacean compositions, a comparison of trophic guilds has been attempted, with fish and decapods classified as: 1 migrator macroplankton feeders (mM, 2 non-migrator macroplankton feeders (nmM, 3 nektobenthos-suprabenthos feeders (NS, 4 epibenthos feeders (Epib, 5 large detritus-scavengers (Sca, 6 infaunal feeders (Inf, 7 deposit feeders (Dep and 8 small detritivorous feeders (Det. Multivariate techniques showed the following differences in the trophodynamics of the megafaunal assemblages along the coasts of the Iberian Peninsula: 1 crustaceans (mainly decapods have different trophic structures on the shelf and on the slope; 2 on the slope, fish exhibited more clear changes as a function of the geographical gradient than crustaceans; and 3 trophodynamics of bathyal fish showed some geographic variations between the Alborán Sea, the Catalano-Balearic Basin, and the Algerian Basin (Vera Gulf and Alicante sectors, with a progressive north-south increase in planktophagous species.

  14. Technical report on NEDO-conducted Western US steam coal (for power generation and boiler) survey

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1982-03-01

    The New Energy and Industrial Technology Development Organization (NEDO) conducted studies covering Wyoming, Utah, Colorado, New Mexico, and North Dakota, all in the West. Illinois and Gulf-Texas are also included. The bituminous coal of Utah and Colorado is given the highest priority as coal to be exported to Japan. It is feared, however, that the price of the bituminous coal from these areas may soar if demand increases. As for sub-bituminous coal, its price is far more stable because its reserves are basically limitless. The sub-bituminous coal, however, is not expected to be imported to Japan in the very near future because it is low in calorific power and fails to meet the conditions prerequisite to Japan's boiler fuel. Illinois can receive large orders but its coal contains more sulfur than the Western coal and a longer distance has to be covered for its transportation. As for transportation to the West Cost, freight cars are available and the port capacity can be enlarged dependent on the magnitude of demand for coal. Loading a deep draft bulk ship off shore with coarse coal slurry by pipeline is an attractive scheme. (NEDO)

  15. Language barriers in the community pharmacy: a survey of northern and western Auckland.

    Science.gov (United States)

    Chang, Emily; Tsang, Bobby; Thornley, Simon

    2011-06-01

    Community pharmacists play an important role in increasing patient understanding of medication use. Lack of resources to facilitate communication with non-English speaking (NES) patients may be a communication barrier. To identify obstacles and coping strategies of community pharmacists when counselling NES patients in Auckland's North Shore and West Auckland. A cross-sectional survey of 46 community pharmacies in West Auckland and the northern Auckland region was carried out in February 2009. Community pharmacists frequently counsel NES patients (65% reported at least once a week). Use of bilingual staff was the most commonly employed strategy (78% of respondents) to communicate with these customers. Pharmacies that reported serving NES clients at least daily all had bilingual staff, compared with 70% of pharmacies with less frequent NES contact (p=0.017). No pharmacists reported using professional interpreting services. In our sample, telephone interpreting was the most preferred (63% of respondents) method of communicating with such patients, assuming that further services were made available. Community pharmacists frequently serve NES patients, with limited access to interpreting services or translated resources. Although pharmacists have, in some way, adapted to the needs of their patients, our survey suggests that accessible professional interpreting services would further improve pharmacist/NES client interaction.

  16. Statistics for Community Governance: The Yawuru Indigenous Population Survey, Western Australia

    Directory of Open Access Journals (Sweden)

    John Taylor

    2014-04-01

    Full Text Available This article presents a case study of an exercise in Aboriginal community governance in Australia. It sets out the background events that led the Yawuru Native Title Holders Aboriginal Corporation in the town of Broome on Australia’s northwest coast to secure information for its own needs as an act of self-determination and essential governance, and it presents some of the key findings from that exercise. As the Indigenous rights agenda shifts from the pursuit of restitution to the management and implementation of benefits, those with proprietary rights are finding it increasingly necessary to build internal capacity for post-native title governance and community planning, including in the area of information retrieval and application. As an incorporated land-holding group, the Yawuru people of Broome are amongst the first in Australia to move in this area of information gathering, certainly in terms of the degree of local control, participation, and conceptual thinking around the logistics and rationale for such an exercise. An innovative addition has been the incorporation of survey output data into a Geographic Information System to provide for spatial analysis and a decision support mechanism for local community planning. In launching and administering the "Knowing our Community" household survey in Broome, the Yawuru have set a precedent in the acquisition and application of demographic information for internal planning and community development in the post-native title determination era.

  17. An ethnobotanical survey of medicinal plants used in Terai forest of western Nepal

    Directory of Open Access Journals (Sweden)

    Singh Anant

    2012-05-01

    Full Text Available Abstract Background Nepal Himalayas have been known as a rich source for valuable medicinal plants since Vedic periods. Present work is the documentation of indigenous knowledge on plant utilization as natural remedy by the inhabitants of terai forest in Western Nepal. Methods Study was conducted during 2010–2011 following standard ethnobotanical methods. Data about medicinal uses of plants were collected by questionnaire, personal interview and group discussion with pre identified informants. Voucher specimens were collected with the help of informants, processed into herbarium following standard methods, identified with the help of pertinent floras and taxonomic experts, and submitted in Department of Botany, Butwal Multiple Campus, Tribhuvan University, Nepal for future references. Results During the present study 66 medicinal plant species belonging to 37 families and 60 genera has been documented. These plants were used to treat various diseases and ailments grouped under 11 disease categories, with the highest number of species (41 being used for gastro-intestinal disorders, followed by dermatological disorders (34. In the study area the informants’ consensus about usages of medicinal plants ranges from 0.93 to 0.97 with an average value of 0.94. Herbs (53% were the primary source of medicine, followed by trees (23%. Curcuma longa (84% and Azadirachta indica (76% are the most frequently and popularly used medicinal plant species in the study area. Acacia catechu, Bacopa monnieri, Bombax ceiba, Drymaria diandra, Rauvolfia serpentina, and Tribulus terrestris are threatened species which needs to be conserved for future use. Conclusions The high degree of consensus among the informants suggests that current use and knowledge are still strong, and thus the preservation of today's knowledge shows good foresight in acting before much has been lost. The connections between plant use and conservation are also important ones, especially as the

  18. Qualitative Interpretation Of Aerogravity And Aeromagnetic Survey Data Over The South Western Part Of The Volta River Basin Of Ghana

    Directory of Open Access Journals (Sweden)

    George Hinson

    2015-04-01

    Full Text Available Abstract The study area South western part of Volta River Basin of Ghana covering an area of 8570 km2 which is one-eleventh the area of the Volta River basin of Ghana has been subjected to numerous academic research works but geophysical survey works because of virtual perceptive reasons. It is now believed to overly mineral-rich geological structures hence the use of magnetic and gravity survey methods to bring out these mineral-rich geological structures.Geographically it study area is located at the south western part of the Voltaian basin at latitudes 07o 00 N and 08o 00 N and longitudes 02o 00 W and 01o 00 W respectively. Airborne gravity and magnetic survey methods were employed in the data collection. The field data correction and error reduction were applied to the two raw data on the field after which Geosoft Oasis Montaj 7.01 Encom Profile Analysis P.A 11 and 13 Model Vision 12 and ArcGIS 10.0 were used to process enhance e.g. reduce to pole at low latitude first vertical derivative etc. model the reduced and corrected airborne magnetic data and also to produce maps from them data. Low-to-moderate-to-high gravity and magnetic anomalies were obtained in the complete Bouguer anomaly CBA and total magnetic intensity TMI reduced to pole at low latitude with many of these anomalies trending NE-SW by which the Birimian Metasediments and Metavolcanics can be said to be part of the causative structures of these anomalies with cross-cut NW-SE faults. From the quantitative point of view the intrusive granitic bodies of the study area have a mean depth location of 1.7 km while the isolated anomaly is located at a depth of 1.4 km computed from Euler deconvolution. The NE-SW trending anomalies show the trend direction of their causative structures which are the basement rocks and the basinal intrusive bodies.

  19. A survey of the summer coccolithophore community in the western Barents Sea

    Science.gov (United States)

    Giraudeau, Jacques; Hulot, Vivien; Hanquiez, Vincent; Devaux, Ludovic; Howa, Hélène; Garlan, Thierry

    2016-06-01

    The Barents Sea is particularly vulnerable to large-scale hydro-climatic changes associated with the polar amplification of climate change. Key oceanographical variables in this region are the seasonal development of sea-ice and the location and strength of physico-chemical gradients in the surface and subsurface water layers induced by the convergence of Arctic- and Atlantic-derived water masses. Remote sensing imagery have highlighted the increasing success of calcifying haptophytes (coccolithophores) in the summer phytoplankton production of the Barents Sea over the last 20 years, as a response to an overall larger contribution of Atlantic waters to surface and sub-surface waters, as well as to enhanced sea-ice melt-induced summer stratification of the photic layer. The present study provides a first thorough description of coccolithophore standing stocks and diversity over the shelf and slope of the western Barents Sea from two sets of surface and water column samples collected during August-September 2014 from northern Norway to southern Svalbard. The abundance and composition of coccolithophore cells and skeletal remains (coccoliths) are discussed in view of the physical-chemical-biological status of the surface waters and water column based on in-situ (temperature, salinity, fluorescence) and shore-based (microscope enumerations, chemotaxonomy) measurements, as well as satellite-derived data (Chl a and particulate inorganic carbon contents). The coccolithophore population is characterized by a low species diversity and the overwhelming dominance of Emiliania huxleyi. Coccolithophores are abundant both within the well stratified, Norwegian coastal water - influenced shallow mixed layer off northern Norway, as well as within well-mixed cool Atlantic water in close vicinity of the Polar Front. Bloom concentrations with standing stocks larger than 4 million cells/l are recorded in the latter area north of 75°N. Our limited set of chemotaxonomic data suggests

  20. Access to affordable medicines after health reform: evidence from two cross-sectional surveys in Shaanxi Province, western China.

    Science.gov (United States)

    Fang, Yu; Wagner, Anita K; Yang, Shimin; Jiang, Minghuan; Zhang, Fang; Ross-Degnan, Dennis

    2013-10-01

    Limited access to essential medicines is a global problem. Improving availability and affordability of essential medicines is a key objective of the National Essential Medicine Policy (NEMP) in China. In its initial implementation in 2009, the NEMP targeted primary hospitals with policies designed to increase availability of essential medicines and reduce patients' economic burden from purchasing medicines. We assessed medicine availability and price during the early years of the health reform in Shaanxi Province in underdeveloped western China. We undertook two public (hospitals) and private (pharmacy) sector surveys of prices and availability of medicines, in September, 2010 and April, 2012, by a standard methodology developed by WHO and Health Action International. We measured medicine availability in outlets at the time of the surveys and inflation-adjusted median unit prices (MUPs), taking 2010 as the base year. We used general estimating equations to calculate the significance of differences in availability from 2010 to 2012 and the Wilcoxon signed rank test to calculate the significance of differences in adjusted median prices. We collected data from 50 public sector hospitals and 36 private sector retail pharmacies in 2010 and 72 public hospitals and 72 retail pharmacies in 2012. Mean availability of surveyed medicines was low in both the public and private sectors; availability of many essential medicines decreased from 2010 to 2012, particularly in primary hospitals (from 27·4% to 22·3% for lowest priced generics; pFund (71103141/G0308), the China Medical Board Faculty Development Awards, the Fundamental Research Funds for the Central Universities (2011jdhz62), the Shaanxi Provincial Social Science Fund (10E066), and the Harvard Medical School Pharmaceutical Policy Research Fellowship. Copyright © 2013 Fang et al. Open Access article distributed under the terms of CC BY-NC-ND. Published by .. All rights reserved.

  1. Settlement patterns and communication routes of the western Maya wetlands: An archaeological and remote-sensing survey, Chunchucmil, Yucatan, Mexico

    Science.gov (United States)

    Hixson, David R.

    This dissertation investigates the role of the seasonal wetlands in the political economy and subsistence strategies of the ancient Maya of Chunchucmil, Yucatan, Mexico. A combination of pedestrian surveys and remote-sensing tasks were performed in order to better understand the settlement patterns and potential communication routes in and through the wetlands between Chunchucmil and the Gulf of Mexico. These western wetlands had been proposed as the principal avenue for interregional trade between coastal merchants and inland consumers, yet were thought to be uninhabited and uncultivable. Following the survey tasks outlined in this dissertation, these wetlands were found to contain an abundance of archaeological settlements and features indicating habitation, utilization, and trade throughout this diverse ecological zone. The remote-sensing platforms utilized in this study include both multispectral (Landsat) and synthetic aperture radar (AirSAR), combined with additional remotely sensed resources. One of the goals of this survey was to test the capabilities of these two sensors for the direct detection of archaeological features from air and space. The results indicate that Landsat can be highly successful at detecting site location and measuring site size under certain environmental conditions. The Airborne Synthetic Aperture Radar proved to be adept at detecting large mounded architecture within the Yucatecan karstic plain, but its further utility is hampered by limitations of resolution, scale, and land cover. One of the salient features of the landscape west of Chunchucmil is a network of stone pathways called andadores. These avenues through the wetlands outline a dendritic network of communication, trade, and extraction routes. The following dissertation places this network and its associated settlements (from suburban centers to diminutive camps) within their regional context, examining the roles they may have played in supporting a large mercantile

  2. Abundance, behavior, and movement patterns of western gray whales in relation to a 3-D seismic survey, Northeast Sakhalin Island, Russia

    OpenAIRE

    Gailey, Glenn; W?rsig, Bernd; McDonald, Trent L.

    2007-01-01

    A geophysical seismic survey was conducted in the summer of 2001 off the northeastern coast of Sakhalin Island, Russia. The area of seismic exploration was immediately adjacent to the Piltun feeding grounds of the endangered western gray whale (Eschrichtius robustus). This study investigates relative abundance, behavior, and movement patterns of gray whales in relation to occurrence and proximity to the seismic survey by employing scan sampling, focal follow, and theodolite tracking methodolo...

  3. Association of common mental disorder symptoms with health and healthcare factors among women in rural western India: results of a cross-sectional survey

    OpenAIRE

    Soni, Apurv; Fahey, Nisha; Byatt, Nancy; Prabhakaran, Anusha; Moore Simas, Tiffany A.; Vankar, Jagdish; Phatak, Ajay; O'Keefe, Eileen; Allison, Jeroan; Nimbalkar, Somashekhar

    2016-01-01

    Objectives Information about common mental disorders (CMD) is needed to guide policy and clinical interventions in low-income and middle-income countries. This study's purpose was to characterise the association of CMD symptoms with 3 inter-related health and healthcare factors among women from rural western India based on a representative, cross-sectional survey. Setting Surveys were conducted in the waiting area of various outpatient clinics at a tertiary care hospital and in 16 rural villa...

  4. Residential, soil and water radon surveys in north-western part of Romania.

    Science.gov (United States)

    Cucoş Dinu, Alexandra; Papp, Botond; Dicu, Tiberius; Moldovan, Mircea; Burghele, Denissa Bety; Moraru, Ionuţ Tudor; Tenţer, Ancuţa; Cosma, Constantin

    2017-01-01

    The exposure to radon and radon decay products in homes and at workplaces represents the greatest risk from natural ionizing radiation. The present study brings forward the residential, soil and water radon surveys in 5 counties of Romania. Indoor radon measurements were performed by using CR-39 track detectors exposed for 3 months on ground-floor level of dwellings, according to the NRPB Measurements Protocol. Radon concentrations in soil and water were measured using the LUK3C device. The indoor radon concentrations ranged from 5 to 2592 Bq⋅m-3 with an updated preliminary arithmetic mean of 133 Bq⋅m-3, and a geometric mean of 90 Bq⋅m-3. In about 6% of the investigated grid cells the indoor radon concentrations exceed the threshold of 300 Bq⋅m-3. The soil gas radon concentration varies from 0.8 to 169 kBq⋅m-3, with a geometric mean of 28.4 kBq⋅m-3. For water samples, the results show radon concentrations within the range of 0.3-352 kBq⋅m-3 with a geometric mean of 7.7 Bq⋅L-1. The indoor radon map was plotted on a reference grid developed by JRC with the resolution 10 × 10 km2. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Calibration of a transient transport model to tritium data in streams and simulation of groundwater ages in the western Lake Taupo catchment, New Zealand

    Directory of Open Access Journals (Sweden)

    M. A. Gusyev

    2013-03-01

    Full Text Available Here we present a general approach of calibrating transient transport models to tritium concentrations in river waters developed for the MT3DMS/MODFLOW model of the western Lake Taupo catchment, New Zealand. Tritium has a known pulse-shaped input to groundwater systems due to the bomb tritium in the early 1960s and, with its radioactive half-life of 12.32 yr, allows for the determination of the groundwater age. In the transport model, the tritium input (measured in rainfall passes through the groundwater system, and the simulated tritium concentrations are matched to the measured tritium concentrations in the river and stream outlets for the Waihaha, Whanganui, Whareroa, Kuratau and Omori catchments from 2000–2007. For the Kuratau River, tritium was also measured between 1960 and 1970, which allowed us to fine-tune the transport model for the simulated bomb-peak tritium concentrations. In order to incorporate small surface water features in detail, an 80 m uniform grid cell size was selected in the steady-state MODFLOW model for the model area of 1072 km2. The groundwater flow model was first calibrated to groundwater levels and stream baseflow observations. Then, the transient tritium transport MT3DMS model was matched to the measured tritium concentrations in streams and rivers, which are the natural discharge of the groundwater system. The tritium concentrations in the rivers and streams correspond to the residence time of the water in the groundwater system (groundwater age and mixing of water with different age. The transport model output showed a good agreement with the measured tritium values. Finally, the tritium-calibrated MT3DMS model is applied to simulate groundwater ages, which are used to obtain groundwater age distributions with mean residence times (MRTs in streams and rivers for the five catchments. The effect of regional and local hydrogeology on the simulated groundwater ages is investigated by demonstrating groundwater ages

  6. Status report of the 1989 Survey of Hunter Activity and Harvest on the Swan Lake Public Hunting Area

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A half-day hunting restriction for the Swan Lake Public Hunting Area (SLPHA) has been recommended to- improve goose use of food resources within hunting zones. The...

  7. Small mammal trapping baseline surveys Mother Goose Lake, Alaska Peninsula/Becharof NWR, Alaska, June-August, 1999

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Small mammal trapping at Mother Goose Lake continued on the Alaska Peninsula National Wildlife Refuge for the fifth consecutive year. Live trapping was conducted...

  8. Small mammal trapping baseline surveys Mother Goose Lake, Alaska Peninsula/Becharof NWR, Alaska, June-August, 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Small mammal trapping at Mother Goose Lake continued on the Alaska Peninsula National Wildlife Refuge for the sixth consecutive year. Live trapping was conducted...

  9. Malacological survey and geographical distribution of vector snails for schistosomiasis within informal settlements of Kisumu City, western Kenya

    Science.gov (United States)

    2011-01-01

    Background Although schistosomiasis is generally considered a rural phenomenon, infections have been reported within urban settings. Based on observations of high prevalence of Schistosoma mansoni infection in schools within the informal settlements of Kisumu City, a follow-up malacological survey incorporating 81 sites within 6 informal settlements of the City was conducted to determine the presence of intermediate host snails and ascertain whether active transmission was occurring within these areas. Methods Surveyed sites were mapped using a geographical information system. Cercaria shedding was determined from snails and species of snails identified based on shell morphology. Vegetation cover and presence of algal mass at the sites was recorded, and the physico-chemical characteristics of the water including pH and temperature were determined using a pH meter with a glass electrode and a temperature probe. Results Out of 1,059 snails collected, 407 (38.4%) were putatively identified as Biomphalaria sudanica, 425 (40.1%) as Biomphalaria pfeifferi and 227 (21.5%) as Bulinus globosus. The spatial distribution of snails was clustered, with few sites accounting for most of the snails. The highest snail abundance was recorded in Nyamasaria (543 snails) followed by Nyalenda B (313 snails). As expected, the mean snail abundance was higher along the lakeshore (18 ± 12 snails) compared to inland sites (dams, rivers and springs) (11 ± 32 snails) (F1, 79 = 38.8, P snails collected shed schistosome cercariae. Interestingly, the proportion of infected Biomphalaria snails was higher in the inland (2.7%) compared to the lakeshore sites (0.3%) (P = 0.0109). B. sudanica was more abundant in sites along the lakeshore whereas B. pfeifferi and B. globosus were more abundant in the inland sites. Biomphalaria and Bulinus snails were found at 16 and 11 out of the 56 inland sites, respectively. Conclusions The high abundance of Biomphalaria and Bulinus spp. as well as observation of

  10. PCB concentrations in lake trout (Salvelinus namaycush) are correlated to habitat use and lake characteristics.

    Science.gov (United States)

    Guildford, S J; Muir, D C G; Houde, M; Evans, M S; Kidd, K A; Whittle, D M; Drouillard, K; Wang, X; Anderson, M R; Bronte, C R; Devault, D S; Haffner, D; Payne, J; Kling, H J

    2008-11-15

    This study considers the importance of lake trout habitat as a factor determining persistent organochlorine (OC) concentration. Lake trout is a stenothermal, cold water species and sensitive to hypoxia. Thus, factors such as lake depth, thermal stratification, and phosphorus enrichment may determine not only which lakes can support lake trout but may also influence among-lake variability in lake trout population characteristics including bioaccumulation of OCs. A survey of 23 lakes spanning much of the natural latitudinal distribution of lake trout provided a range of lake trout habitat to test the hypothesis that lake trout with greater access to littoral habitat for feeding will have lower concentrations of OCs than lake trout that are more restricted to pelagic habitat. Using the delta13C stable isotope signature in lake trout as an indicator of influence of benthic littoral feeding, we found a negative correlation between lipid-corrected delta13C and sigmaPCB concentrations supporting the hypothesis that increasing accessto littoral habitat results in lower OCs in lake trout. The prominence of mixotrophic phytoplankton in lakes with more contaminated lake trout indicated the pelagic microbial food web may exacerbate the biomagnification of OCs when lake trout are restricted to pelagic feeding. A model that predicted sigmaPCB in lake trout based on lake area and latitude (used as proximate variables for proportion of littoral versus pelagic habitat and accessibility to littoral habitat respectively) explained 73% of the variability in sigmaPCBs in lake trout in the 23 lakes surveyed.

  11. Phylogenies of microcystin-producing cyanobacteria in the lower Laurentian Great Lakes suggest extensive genetic connectivity.

    Directory of Open Access Journals (Sweden)

    Timothy W Davis

    Full Text Available Lake St. Clair is the smallest lake in the Laurentian Great Lakes system. MODIS satellite imagery suggests that high algal biomass events have occurred annually along the southern shore during late summer. In this study, we evaluated these events and tested the hypothesis that summer bloom material derived from Lake St. Clair may enter Lake Erie via the Detroit River and represent an overlooked source of potentially toxic Microcystis biomass to the western basin of Lake Erie. We conducted a seasonally and spatially resolved study carried out in the summer of 2013. Our goals were to: 1 track the development of the 2013 summer south-east shore bloom 2 conduct a spatial survey to characterize the extent of toxicity, taxonomic diversity of the total phytoplankton population and the phylogenetic diversity of potential MC-producing cyanobacteria (Microcystis, Planktothrix and Anabaena during a high biomass event, and 3 compare the strains of potential MC-producers in Lake St. Clair with strains from Lake Erie and Lake Ontario. Our results demonstrated a clear predominance of cyanobacteria during a late August bloom event, primarily dominated by Microcystis, which we traced along the Lake St. Clair coastline downstream to the Detroit River's outflow at Lake Erie. Microcystin levels exceeded the Province of Ontario Drinking Water Quality Standard (1.5 µg L(-1 for safe drinking water at most sites, reaching up to five times this level in some areas. Microcystis was the predominant microcystin producer, and all toxic Microcystis strains found in Lake St. Clair were genetically similar to toxic Microcystis strains found in lakes Erie and Ontario. These findings suggest extensive genetic connectivity among the three systems.

  12. Coastal groundwater/surface-water interactions: a Great Lakes case study

    Science.gov (United States)

    Neff, Brian P.; Haack, Sheridan K.; Rosenberry, Donald O.; Savino, Jacqueline F.; Lundstrom, Scott C.

    2006-01-01

    Key similarities exist between marine and Great Lakes coastal environments. Water and nutrient fluxes across lakebeds in the Great Lakes are influenced by seiche and wind set-up and set-down, analogous to tidal influence in marine settings. Groundwater/surface-water interactions also commonly involve a saline-fresh water interface, although in the Great-Lakes cases, it is groundwater that is commonly saline and surface water that is fresh. Evapotranspiration also affects nearshore hydrology in both settings. Interactions between groundwater and surface water have recently been identified as an important component of ecological processes in the Great Lakes. Water withdrawals and the reversal of the groundwater/surface water seepage gradient are also common to many coastal areas around the Great Lakes. As compared to surface water, regional groundwater that discharges to western Lake Erie from Michigan is highly mineralized. Studies conducted by the U.S. Geological Survey at Erie State Game Area in southeastern Michigan, describe groundwater flow dynamics and chemistry, shallow lake-water chemistry, and fish and invertebrate communities. Results presented here provide an overview of recent progress of ongoing interdisciplinary studies of Great Lakes nearshore systems and describe a conceptual model that identifies relations among geologic, hydrologic, chemical, and biological processes in the coastal habitats of Lake Erie. This conceptual model is based on analysis of hydraulic head in piezometers at the study site and chemical analysis of deep and shallow coastal groundwater.

  13. Ethnopharmacological survey on medicinal plants used in snakebite treatments in Western and Sabaragamuwa provinces in Sri Lanka.

    Science.gov (United States)

    Dharmadasa, R M; Akalanka, G C; Muthukumarana, P R M; Wijesekara, R G S

    2016-02-17

    Sri Lanka has a great diversity of snake species. In this relation, over 40,000 cases of snakebite accidents are reported annually from different agro-ecological regions of the country. Since more than 95% of victims rely on traditional treatments, there is an urgent necessity to improve the system. Traditional knowledge on snakebite treatments has been passed on from generation to generation within families. Unfortunately, there has been a limited update of information on pertinent issues related to this subject. In the present study we conducted a comprehensive survey on the types of medicinal plant materials, including the specific plant parts that are available for this purpose. In addition, various treatment types, frequency index, heavily used and rare materials, family wise distribution, challenges faced by traditional practitioners and future prospects were also explored. The present survey covered two provinces with a high population of traditional practitioners for snakebites treatment in Sri Lanka.Information was gathered from a total of seventy-four (74) traditional practitioners from the Sabaragamuwa and Western provinces. A questionnaire was prepared and pre-tested by 10-15 respondents prior to the survey. Actual data were gathered through face-to-face interviews. Collected data were tabulated and analyzed. A total of 341 different plant species belonging to 99 families were documented. The highest number of plants was reported from the family Fabaceae (32 species). This was followed by Malvaceae (16 species), Asteraceae (15 species), Rutaceae (13 species Apocyanaceae (14 species), Lamiaceae (11 species), Poaceae, Euphorbaceae and Phyllanthaceae (10 species per each) respectively. Different parts of the plant such as leaves (53.67%), barks (26.10%), entire plant (14.08%), roots (10.26%), bulbs (8.80%), seeds (7.62%), fruits (6.45%), buds (5.87%), flowers (3.23%) stems (2.93%) and latex (2.05%) were used for the preparation of nine different types of

  14. Lake Superior revisited 1984

    Science.gov (United States)

    MacCallum, Wayne R.; Selgeby, James H.

    1987-01-01

    The Lake Superior fish community has changed substantially since the early 1960s, when control of the sea lamprey (Petromyzon marinus) became effective. Self-reproducing stocks of lake trout (Salvelinus namaycush) have been reestablished in many inshore areas, although they have not yet reached pre-sea lamprey abundance; offshore lake trout are probably at or near pre-sea lamprey abundance. Stocks of lake whitefish (Coregonus clupeaformis) appear to have fully recovered; commercial catches are at or above historical levels. Lake herring (Coregonus artedii) are recovering rapidly in U.S. waters and are abundant in western Canadian waters. The population of rainbow smelt (Osmerus mordax), which declined in the 1970s, is recovering. Pacific salmon (Oncorhynchus) are becoming more abundant as a result of increased stocking in U.S. waters and are reproducing in most suitable tributaries; they have become significant in anglers' creels.

  15. Microcystin concentrations and genetic diversity of Microcystis in the lower Great Lakes.

    Science.gov (United States)

    Dyble, Julianne; Fahnenstiel, Gary L; Litaker, R Wayne; Millie, David F; Tester, Patricia A

    2008-08-01

    The resurgence of Microcystis blooms in the lower Great Lakes region is of great concern to public and ecosystem health due to the potential for these colonial cyanobacteria to produce hepatotoxic microcystins. A survey of Microcystis cell densities and microcystin concentrations during August 2004 showed particularly high concentrations of both cells and toxin in the nearshore regions of Saginaw Bay (Lake Huron) and western Lake Erie, often exceeding the World Health Organization's recommended drinking water limit of 1 microg L(-1). The dominant congener of microcystin in both basins was microcystin-LR (MC-LR), whereas the second most abundant congeners, accounting for up to 20-25% of the total microcystin concentrations, were MC-LA in Saginaw Bay and MC-RR in western Lake Erie. Multiplex PCR assays of Microcystis colonies isolated from these two regions showed that a much greater percentage of the Microcystis colonies from Saginaw Bay carried the mcyB gene necessary for microcystin production, in comparison with those from western Lake Erie. The mcyB genotypes sequenced separated into two distinct phylogenetic clusters, with Microcystis originating from Lake Erie predominantly in one branch and from Saginaw Bay present in both branches. These results indicate that the genetic composition of the bloom could impact the concentrations and congeners of microcystin produced and that the cell count methods currently being used to gauge public health threats posed by Microcystis blooms may not sufficiently assess actual bloom toxicity.

  16. Neotectonic fault structures in the Lake Thun area (Switzerland)

    Science.gov (United States)

    Fabbri, Stefano C.; Herwegh, Marco; Schlunegger, Fritz; Hübscher, Christian; Weiss, Benedikt J.; Schmelzbach, Cédric; Horstmeyer, Heinrich; Merz, Kaspar; Anselmetti, Flavio S.

    2016-04-01

    Strong historic earthquakes (i.e. intensities I0 ≥ V) in Switzerland are well documented by the earthquake catalogue of Switzerland ECOS-09 (e.g. Frutigen, 1729 AD, Mw=5.2, I0=VI). Many of these strong events can be recognized paleoseismically by large subaquatic, earthquake-triggered mass movements that occur frequently in Swiss Lakes. Some of these represent the occasional occurrence of even stronger earthquakes (i.e. Mw ˜6.5) in the Alpine region (Strasser et al., 2013), which are expected to produce noticeable surface ruptures. However, convincing evidence for Quaternary displacements with offset surface expressions have scarcely been found (e.g., Wiemer et al., 2009). Applying a multi-disciplinary approach, this study presents potential candidates for such faults in the larger Lake Thun area at the edge of the Alps. The overdeepened basin of Lake Thun is situated at the northern Alpine front, which extends orthogonally to the general strike direction of the Alpine nappe front. The northern shoreline is predominantly shaped by the front of the Subalpine Molasse, which is in strong contrast to the south western shore built by the structurally higher units of the Middle and Lower Penninic nappes. This pattern with obvious differences of both lake sides suggests a major fault along the lake axis and high tectonic activity during nappe emplacement, i.e. from Eocene times throughout the Late Miocene. The area is dominated today by a strike-slip stress regime with a slight normal faulting component (Kastrup et al., 2004). As part of a multi-disciplinary study, attempting to find potential neotectonically active fault structures in the Lake Thun area, a 2D ground penetrating radar (GPR) survey was conducted. The aim of the GPR survey was to link observations from a multichannel reflection seismic survey and a multibeam bathymetric survey carried out in Lake Thun with findings in a nearby gravel quarry revealing suspicious deformation features such as rotated gravel

  17. Modelling regional response of lakewater chemistry to changes in acidic deposition: the MAGIC model applied to lake surveys in southernmost Norway 1974-1986-1995

    Directory of Open Access Journals (Sweden)

    B. J. Cosby

    1998-01-01

    Full Text Available Two methods for modelling regional responses of lake water quality to changes in acidic deposition in southernmost Norway were examined. Both methods are based upon the MAGIC model but differ in mode of regional application; one uses site-specific while the other uses Monte-Carlo methods for model calibration. The simulations of regional responses from both methods were compared with observed responses based on data from three lake surveys in southernmost Norway conducted in 1974, 1986 and 1995. The regional responses of the two modelling approaches were quite similar and agreed well with the observed regional distributions of lakewater chemistry variables. From 1974 to 1986 the observed data indicated that despite a decline of approximately 10% in sulphate (SO4 deposition, the mean acid neutralizing capacity (ANC of lakes in southernmost Norway declined by approximately 6 μeq l-1. Both modelling approaches simulated no change or a very small decline in mean ANC for that period. From 1986 to 1995 the observed data indicated that, in response to an approximate 40% decline in SO4 deposition, the mean ANC of lakes in southernmost Norway increased by 11-16 μeq l-1. The modelling approaches simulated increases of 9-10 μeq l-1 in mean ANC for the same period. Both simulations and observations indicate that > 65% of lakes in southernmost Norway were acidic in 1974 and 1995. Both simulation methods predict that >65% of the lakes in southernmost Norway will have positive ANC values within 10 years of reductions of SO4 deposition to 20% of 1974 levels. Of the two regionalization methods the site-specific method appears preferable, because whereas the Monte-Carlo method gives results for a region as a whole, the site-specific method also reveals patterns within the region. The maintenance of a one-to-one correspondence between simulated and observed systems means that simulation results can be mapped for a geographically explicit presentation of model

  18. Seafloor geodetic survey revealed partial creep of North Anatolian Fault at the western part of the Sea of Marmara, Turkey

    Science.gov (United States)

    Kido, Motoyuki; Yamamoto, Ryusuke; Ohta, Yusaku; Takahashi, Narumi; Yamamoto, Yujiro; Kalafat, Dogan; Pinar, Ali; Ozener, Haluk; Ozeren, Sinan; Kaneda, Yoshiyuki

    2017-04-01

    exponential decay, but is still visible even after 20 months. Taken together all of these information, we obtained change rate of each baselines and their projections or direction cosines to the fault strike were 9-14 mm/yr indicating right-lateral movement. There still remain a few mm/yr uncertainty in the slip rate, it is obvious that coupling rate of NAF at this site is roughly a half at least near the surface compared to the regional rate of 22-25 mm/year. Looking at onshore GNSS data along a perpendicular line to NAF including the Western High, slight decay of displacement rate at northern and southern innermost sites compared to the regional rate gives some information on the depth extent of the partial coupling. We have extended two additional GNSS site along the line closer to NAF than above sites for more strong constraint on the depth extent in the future, which can be discussed with seismicity distribution obtained by repeated OBS survey.

  19. Pliocene and Quaternary climate evolution of the high Western Arctic derived from initial geochemistry and FTIRS data of the Lake El`gygytgyn sediments, NE Siberia

    Science.gov (United States)

    Wennrich, V.; Kukkonen, M.; Meyer-Jacob, C.; Minyuk, P.; Rosen, P.; Brigham-Grette, J.; Melles, M.; El'Gygytgyn Scientific Party

    2010-12-01

    High arctic Lake El‘gygytgyn (67°30’ N, 172°05’ E) is a 3.6 Ma old meteorite crater lake located in Chukotka/NE Siberia, 100 km to the north of the Arctic Circle. With its continuous and undisturbed sequence since the Pliocene, the lake comprises the most long-lasting climate archive of the terrestrial Arctic. In spring 2009, the ICDP El‘gygytgyn Drilling Project recovered the 317-m long lacustrine sediment record from 170 m water depth at site D1 in the central lake part. Here we present initial results of elemental analyses as well as infrared spectroscopy of this record. The elemental composition of the lake sediment was investigated by a combination of high-resolution element analyses using an ITRAX X-ray Fluorescence (XRF) core scanner (Cox Analytics), and conventional XRF spectrometry. The results well reflect variations in sedimentation, weathering, lake hydrology and productivity mostly triggered by glacial-interglacial cycles. Furthermore, due to the high spatial resolution of the ITRAX even short-term fluctuations of those proxies could be detected, displaying the sensitivity of the Lake El‘gygytgyn sediments to regional and global climate changes on a decadal to centennial scale. Measurements of Fourier Transform Infrared Spectroscopy (FTIRS) in the mid-infrared (MIR) region were conducted to quantitatively estimate contents of biogenic silica (BSi), total nitrogen (TN), total organic carbon (TOC), and total inorganic carbon (TIC) in Lake El‘gygytgyn sediments. Simultaneous inference of these components is possible because IR-spectra in the MIR-region contain a wide variety of information on minerogenic and organic substances. The technique requires only small amounts (0.01g dry weight) of sample material and negligible sample pre-treatments. FTIRS calibrations for BSi, TN, TOC, and TIC based on core catcher samples of the sediment sequence yielded good statistical performances and emphasize the potential of the technique for high

  20. Preserving Urmia Lake in a changing world

    NARCIS (Netherlands)

    Shadkam, Somayeh

    2017-01-01

    Urmia Lake, in north-western Iran, is an important internationally recognized natural area designated as a RAMSAR site and UNESCO Biosphere Reserve. Over the last 20 years, the surface area of Urmia Lake has declined by 80%. As a result, the salinity of the lake has sharply increased which is

  1. Influence of organizational context on nursing home staff burnout: A cross-sectional survey of care aides in Western Canada.

    Science.gov (United States)

    Chamberlain, Stephanie A; Gruneir, Andrea; Hoben, Matthias; Squires, Janet E; Cummings, Greta G; Estabrooks, Carole A

    2017-06-01

    Our study examined care aide characteristics, organizational context, and frequency of dementia-related resident responsive behaviours associated with burnout. Burnout is the experience of emotional exhaustion, cynicism, and professional inefficacy. Care aide burnout has implications for turnover, staff health, and quality of care. We used surveys collected from 1194 care aides from 30 urban nursing homes in three Western Canadian provinces. We used a mixed-effects regression analysis to assess care aide characteristics, dementia-related responsive behaviours, unit and facility characteristics, and organizational context predictors of care aide burnout. We measured burnout using the Maslach Burnout Inventory, Short Form. We found that care aides were at high risk for emotional exhaustion and cynicism, but report high professional efficacy. Statistically significant predictors of emotional exhaustion included English as a second language, medium facility size, organizational slack-staff, organizational slack-space, health (mental and physical) and dementia-related responsive behaviours. Statistically significant predictors of cynicism were care aide age, English as a second language, unit culture, evaluation (feedback of data), formal interactions, health (mental and physical) and dementia-related responsive behaviours. Statistically significant predictors of professional efficacy were unit culture and structural resources. Greater care aide job satisfaction was significantly associated with increased professional efficacy. This study suggests that individual care aide and organization features are both predictive of care aide burnout. Unlike care aide or structural characteristics of the facility elements of the organizational context are potentially modifiable, and therefore amenable to intervention. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Audio-magnetotelluric surveys to constrain the origin of a network of narrow synclines in Eocene limestone, Western Desert, Egypt

    Science.gov (United States)

    Tarabees, Elhamy A.; Tewksbury, Barbara J.; Mehrtens, Charlotte J.; Younis, Abdellatif

    2017-12-01

    Recent work with high resolution satellite imagery has revealed a network of narrow synclines developed during the Oligocene or Miocene over tens of thousands of square kilometers in Eocene limestone of the Thebes Group in the Western Desert of Egypt. The synclines are non-tectonic, and their scale and geometry strongly resemble sag synclines in Qatar that were produced by dissolution of subsurface evaporites and resulting sag of overlying layers. Evaporite dissolution cannot explain the Egypt synclines, because subsurface evaporites of any significance have never been reported in this part of Egypt. In this study, we use audio-magnetotelluric surveys to illuminate the subsurface under the synclines in order to constrain possible models for their formation. We suspected karst dissolution at depth, and, given a modern water table depth of over 400 m, we expected that dry fracture networks and void spaces under the synclines might result in higher electrical resistivities than surrounding coherent limestone. We also anticipated a significant change from high to low resistivity at the contact between the Thebes Group and the underlying Esna Shale at depths of 400 m or more. Instead, we found localized low resistivity zones extending from about 50-100 m below the surface to depths of more than 400 m that are strongly correlated with synclines. We suggest that these localized low resistivity zones are filled with artesian groundwater that has insufficient hydraulic head to rise to the modern topographic surface and that is localized in subsurface voids and collapse breccias produced by dissolution. Sag of overlying limestone layers is a reasonable model for syncline formation but, given the Oligocene/Miocene age of the synclines, dissolution and sag would be unrelated to young groundwater processes.

  3. Sero-epidemiological survey and risk factors associated with brucellosis in dogs in south-western Nigeria.

    Science.gov (United States)

    Ayoola, Modupe Comfort; Ogugua, Akwoba Joseph; Akinseye, Victor Oluwatoyin; Joshua, Tunde Olu; Banuso, Morenikeji Folusho; Adedoyin, Folashade Julianah; Adesokan, Hezekiah Kehinde; Omobowale, Temidayo Olutayo; Abiola, John Olusoji; Otuh, Patricia Ihuaku; Nottidge, Helen Oyebukola; Dale, Emma-Jane; Perrett, Lorraine; Taylor, Andrew; Stack, Judy; Cadmus, Simeon Idowu Babalola

    2016-01-01

    In Nigeria, there is limited information on brucellosis particularly in dogs, despite its public health implications. We undertook a sero-epidemiological survey of brucellosis in dogs to determine the prevalence of the disease and associated risk factors for its occurrence in Nigeria. A cross-sectional study was conducted to screen dogs in south-western Nigeria for antibodies to Brucella sp using the rapid slide agglutination test (RSA) and Rose Bengal test (RBT), with positive samples confirmed respectively by serum agglutination test (SAT) and competitive enzyme linked immunosorbent assay (cELISA). Data were analyzed with STATA-12. From the 739 dog sera tested, 81 (10.96%) were positive by RSA and 94 (12.72%) by RBT; these were corroborated with SAT (4/81; 4.94%) and cELISA (1/94; 1.06%), respectively. Logistic regression identified location (OR=0.04; 95% CI: 0.02-0.09), breed (OR=1.71; 95% CI: 1.34-2.19), age (OR=0.10; 95% CI: 0.04-0.30) and management system (OR=8.51; 95% CI: 1.07-68.05) as risk factors for Brucella infection by RSA. However, location (OR=10.83; 95% CI: 5.48-21.39) and history of infertility (OR=2.62; 95% CI: 1.41-4.84) were identified as risk factors using RBT. Given the 10.96% to 12.72% seroprevalence of brucellosis recorded in this study, we advocate control of the disease in dogs, and public health education for those at risk of infection. Again, further studies are required to elucidate the role of dogs in the epidemiology of brucellosis in Nigeria considering the conducive human-animal interface and ecological factors responsible for the transmission of the disease.

  4. A mass screening survey of cystic echinococcosis by ultrasonography, Western blotting, and ELISA among university students in Manisa, Turkey.

    Science.gov (United States)

    Kilimcioğlu, Ali Ahmet; Girginkardeşler, Nogay; Korkmaz, Metin; Özkol, Mine; Düzgün, Fatih; Östan, Ipek; Pabuşcu, Yüksel; Dinç, Gönül; Ok, Ulgen Zeki

    2013-12-01

    Cystic echinococcosis (CE) is one of the most important zoonotic diseases in a wide geographic area, including Turkey. In the present project, a total of 4275 students from Celal Bayar University, Manisa, Turkey, were screened by ultrasonography (US) and specific antibodies for CE were examined by Western blotting (WB) and ELISA in finger prick blood samples of 2034 of 4275 volunteered students. We aimed to report the apparent prevalence of CE based on different diagnostic procedures and to compare WB and ELISA with US in diagnosis of CE in a mass screening setting. Six new cases were diagnosed as CE by US during the survey. In addition to these cases, three students were also detected to have been previously operated and pathologically confirmed for hepatic CE. US revealed parenchymal changes in these cases in concordance with their operation history; so, the prevalence of CE by US was calculated as 0.21% (9/4275) (95%CI, 0.11-0.39%) among university students in Manisa. Bands were detected at 8, 28, 32, 38, 42, 47, 70 and 90kDa by WB and the cases were considered to be positive for CE when at least three of the bands were seen together. Apparent prevalence of CE by ELISA and WB were found to be 2.11% (43/2034) (95%CI, 1.57-2.83%) and 0.25% (5/2034) (95%CI, 0.10-0.57%), respectively. Of the six US positive cases, WB was positive in only one case with two cysts in the liver. All of four cases with liver involvement were positive by ELISA. The high prevalence of CE among university students in Manisa indicated that CE is a major health problem in this area of Turkey. Our results supported that WB is rather difficult and not feasible as a mass screening test and may not be effective for confirmation especially in asymptomatic cases. As a result, we recommend US to be used initially in mass screening surveys for CE followed by confirmation by ELISA for suspected cases. Further examination primarily by chest X-ray followed by computed tomography and/or magnetic

  5. Estimating cetacean density and abundance in the Central and Western Mediterranean Sea through aerial surveys: Implications for management

    Science.gov (United States)

    Panigada, Simone; Lauriano, Giancarlo; Donovan, Greg; Pierantonio, Nino; Cañadas, Ana; Vázquez, José Antonio; Burt, Louise

    2017-07-01

    Systematic, effective monitoring of animal population parameters underpins successful conservation strategy and wildlife management, but it is often neglected in many regions, including much of the Mediterranean Sea. Nonetheless, a series of systematic multispecies aerial surveys was carried out in the seas around Italy to gather important baseline information on cetacean occurrence, distribution and abundance. The monitored areas included the Pelagos Sanctuary, the Tyrrhenian Sea, portions of the Seas of Corsica and Sardinia, the Ionian Seas as well as the Gulf of Taranto. Overall, approximately 48,000 km were flown in either spring, summer and winter between 2009-2014, covering an area of 444,621 km2. The most commonly observed species were the striped dolphin and the fin whale, with 975 and 83 recorded sightings, respectively. Other sighted cetacean species were the common bottlenose dolphin, the Risso's dolphin, the sperm whale, the pilot whale and the Cuvier's beaked whale. Uncorrected model- and design-based estimates of density and abundance for striped dolphins and fin whales were produced, resulting in a best estimate (model-based) of around 95,000 striped dolphins (CV=11.6%; 95% CI=92,900-120,300) occurring in the Pelagos Sanctuary, Central Tyrrhenian and Western Seas of Corsica and Sardinia combined area in summer 2010. Estimates were also obtained for each individual study region and year. An initial attempt to estimate perception bias for striped dolphins is also provided. The preferred summer 2010 uncorrected best estimate (design-based) for the same areas for fin whales was around 665 (CV=33.1%; 95% CI=350-1260). Estimates are also provided for the individual study regions and years. The results represent baseline data to develop efficient, long-term, systematic monitoring programmes, essential to evaluate trends, as required by a number of national and international frameworks, and stress the need to ensure that surveys are undertaken regularly and

  6. Great Lakes Commercial Fishing Catch 1929-2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Since 1971 the Great Lakes Science Center (GLSC), formerly known as the National Fishery Center-Great Lakes (National Biological Service), the Great Lakes Fishery...

  7. Geology and environments of subglacial Lake Vostok.

    Science.gov (United States)

    Leitchenkov, German L; Antonov, Anton V; Luneov, Pavel I; Lipenkov, Vladimir Ya

    2016-01-28

    The reconstruction of the geological (tectonic) structure and environments of subglacial Lake Vostok is based on geophysical surveys and the study of mineral particles found in cores of accreted ice and frozen lake water (sampled after the lake was unsealed). Seismic reflection and refraction investigations conducted in the southern part of Lake Vostok show very thin (200-300 m) sedimentary cover overlying a crystalline basement. Most of this thin veneer is thought to have been deposited during temperate-glacial conditions in Oligocene to Middle Miocene time (ca 34-14 Ma). The composition of the lake-bottom sediments can be deduced from mineral inclusions found in cores of accreted ice. Inclusions are represented by soft aggregates consisting mainly of clay-mica minerals and micrometre-sized quartz grains. Some of these inclusions contain subangular to semi-rounded rock clasts (siltstones and sandstones) ranging from 0.3 to 8 mm in size. In total, 31 zircon grains have been identified in two rock clasts and dated using SHRIMP-II. The ages of the studied zircons range from 0.6 to 2.0 Ga with two distinct clusters between 0.8 and 1.15 Ga and between 1.6 and 1.8 Ga. Rock clasts obviously came from the western lake shore, which is thus composed of terrigenous strata with an age of not older than 600 Ma. The sedimentary nature of the western lake shore is also confirmed by seismic refraction data showing seismic velocities there of 5.4-5.5 km s(-1) at the bedrock surface. After Lake Vostok was unsealed, its water (frozen and sampled next season) was also studied with scanning electron microscopy and X-ray microprobe analysis. This study showed the existence of calcium carbonate and silica microparticles (10-20 μm across) in frozen water. © 2015 The Author(s).

  8. A reworked Lake Zone margin: Chronological and geochemical constraints from the Ordovician arc-related basement of the Hovd Zone (western Mongolia)

    Czech Academy of Sciences Publication Activity Database

    Soejono, I.; Buriánek, D.; Janoušek, V.; Svojtka, Martin; Čáp, P.; Erban, V.; Ganpurev, D.

    294/295, December (2017), s. 112-132 ISSN 0024-4937 Institutional support: RVO:67985831 Keywords : Ordovician magmatic arc * Mid-Silurian intra-plate magmatism * Hovd Zone * Reworked Lake Zone Subject RIV: DB - Geology ; Mineralogy Impact factor: 3.677, year: 2016

  9. Archaeological Survey of the Proposed Johnston Trails Project in the Downstream Corridor, Saylorville Lake, Polk County, Iowa. Phase 1

    Science.gov (United States)

    1993-01-01

    Creek member overlying a Corrington or Gunder Member allu- vial fan that has been truncated by fluvial activity where it meets the current Des Moines...and Leah D. Rogers 1985 Interlertive Overview of Cultura Resouwves in Say/orvil/e Lake, Iowa, VoL I. Project CAR-627, Cen- ter for Archaeological

  10. Structure and spatial patterns of macrobenthic community in Tai Lake, a large shallow lake, China

    Science.gov (United States)

    Di Li,; Erickson, Richard A.; Song Tang,; Xuwen Li,; Niu, Zhichun; Xia Wang,; Hongling Liu,; Hongxia Yu,

    2016-01-01

    Tai Lake (Chinese: Taihu), the third-largest freshwater lake in China, suffers from harmful cyanobacteria blooms that are caused by economic development and population growth near the lake. Several studies have focused on phytoplankton in Tai Lake after a drinking water crisis in 2007; however, these studies primarily focused on microcystin bioaccumulation and toxicity to individual species without examining the effects of microcystin on macrobenthic community diversity. In this study, we conducted a survey of the lake to examine the effects of microcystine and other pollutants on marcobenthic community diversity. A totally of forty-nine species of macroinvertebrates were found in Tai Lake. Limnodrilus hoffmeisteri and Corbicula fluminea were the most abundant species. Cluster-analysis and one-way analysis of similarity (ANOSIM) identified three significantly different macrobenthic communities among the sample sites. More specifically, sites in the eastern bays, where aquatic macrophytes were abundant, had the highest diversity of macrobenthic communities, which were dominated by Bellamya aeruginosa, Bellamya purificata, L. hoffmeisteri, and Alocinma longicornis. Sites in Zhushan Bay contained relatively diverse communities, mainly composed of L. hoffmeisteri, C. fluminea, L. claparederanus, R. sinicus, and Cythura sp. Sites in the western region, Meiliang Bay and Wuli Bay had the lowest diversity, mainly composed ofL. hoffmeisteri, C. fluminea, Branchiura sowerbyi, and Rhyacodrilus sinicus. In addition, the relationships between macrobenthic metrics (Shannon–Wiener, Margalef, and Pielou) and environmental variables showed that community structure and spatial patterns of macrobenthos in Tai Lake were significantly influenced by chemical oxygen demand (CODCr), biochemical oxygen demand (BOD5), lead (Pb), and microcystin-LR (L for leucine and R for arginine). Our findings provide critical information that could help managers and policymakers

  11. Stockton Lake Survey and Assessment. National Register Assessment of Prehistoric Archeological Sites 23DA407 and 23DA408 and Historic Properties Survey in the Stockton Lake Project, Cedar and Dade Counties, Missouri

    Science.gov (United States)

    1993-01-01

    conducted at Stockton Lake (Girard and Freeman 1992, Mercado -Allinger and Jackson 1989, Nichols et al. 1980) and along the downstream reaches of the Sac...having mounds arranged around a plaza . These centers were surrounded by outlying villages, farmsteads and specialized activity loci where specific...and Freeman 1992; Mercado -Allinger and Jackson 1989 and Nichols et al. 1980). Not all of the research topics posed by these investigators have been

  12. High-resolution multi-proxy reconstruction of Lake Ighiel (Western Carpathians, Romania): processes and controlling factors of lacustrine dynamics during the mid and late Holocene

    Science.gov (United States)

    Haliuc, Aritina; Veres, Daniel; Hubay, Katalin; Begy, Robert; Brauer, Achim; Hutchinson, Simon; Braun, Mihaly

    2016-04-01

    Concerns about current and prospective environmental change have increased the interest in past climate variability and its impact on the bio-hydro-atmosphere and human society. Acting as high-resolution terrestrial archives, lacustrine sediments are the result of the complex interaction between internal and external forcing and an important tool in efforts to resolve questions related to the palaeoclimatic and palaeoenvironmental conditions of the recent past. Here we discuss a new, high-resolution sedimentary record from the Romanian Carpathians (central-eastern Europe). Lake Ighiel (46° 10'50"N, 23° 22'00"E) is a small lake located in a mid-altitude mountain belt (Trascau Mountains) at an altitude of 924 m ( lake maximum depth 9 m; catchment area 487 ha). We employ detailed 210Pb and 14C dating coupled with high-resolution X-ray fluorescence scanning (μ-XRF) measurements, long-core sedimentary logging, environmental magnetic proxies (susceptibility, natural and induced remanences) in an attempt to trace the 6000 years evolution of lake-catchment system. More specifically, we discuss: i) the temporal evolution of the main sedimentation phases of the lake based on sedimentological, geochemical and magnetic proxies; ii) the amplitude and interplay of processes (natural and/or anthropogenic) controlling the depositional environment through time; iii) assess the contribution of each controlling factors and reconstruct the evolution of lacustrine system and palaeoclimate forcing using multivariate statistics. The sedimentary record can be divided into six phases based on alternating high and low detrital fluxes, oscillating lacustrine productivity and redox conditions. A series of detrital events (5200; 4800; 5400; 5250; 4500; 4050; 3800; 3500; 3250; 3050; 2650; 2350; 2250; 1400; 1100; 500; 100 cal yr BP) were identified by microfacies analyses and X-ray fluorescence scanning (μ-XRF) analysis. These events are reflected in most of the parameters and appear

  13. Knowledge, attitude, and practices on intestinal schistosomiasis among primary schoolchildren in the Lake Victoria basin, Rorya District, north-western Tanzania

    Directory of Open Access Journals (Sweden)

    David Z. Munisi

    2017-09-01

    Full Text Available Abstract Background Globally school-age children, adolescents and young adults bear the highest burden of schistosomiasis. When developing a specific intervention to improve community’s knowledge, attitudes, and practices (KAPs, existing KAPs must be taken into account. Therefore, this study was designed to determine schoolchildren’s KAPs on schistosomiasis in the study area. Methods A cross-sectional study was conducted in Busanga and Kibuyi villages involving 513 schoolchildren. A pre-tested questionnaire was used to collect socio-demographic data and to assess KAP on schistosomiasis among primary schoolchildren in the study area. Results Of the 488 interviewed children, 391 (80.12% reported to have heard of schistosomiasis, with the majority 289 (73.91% citing school as the source of this knowledge. Swimming in the lake, worms, witchcraft, and mosquitoes were mentioned to be the cause for intestinal schistosomiasis. Fishing in the lake, drinking unboiled lake water, walking bare footed, and shaking hands were reported to be practices that may lead to contracting schistosomiasis. Only 156 (39.90% of the study respondents reported to know the signs of intestinal schistosomiasis. Avoiding swimming in the lake, drinking unboiled water and eating unwashed fruits were mentioned as preventive measures. Nearly 85% (412 reported understanding that there was a disease known as schistosomiasis; additionally, 419 (85.86% considered schistosomiasis as a dangerous disease and 418 (85.66% believed that schistosomiasis was treatable. Fishermen and schoolchildren were reported to be groups most at risk of schistosomiasis infection. Visiting the lake (for swimming and other gatherings was a common practice among study participants 471 (96.52%.Nearly 93% (451 of participants mentioned using lake water for domestic chores, and, although 407 (84.61% reported to own a toilet at home, only 229 (55.31% reported to always use a toilet for sanitation purposes

  14. A prevalence of cardiometabolic risk factors among a rural Yoruba south-western Nigerian population: a population-based survey.

    Science.gov (United States)

    Oladapo, O O; Salako, L; Sodiq, O; Shoyinka, K; Adedapo, K; Falase, A O

    2010-01-01

    It has been hypothesised that rural sub-Saharan Africa is at an early stage of epidemiological transition from communicable to non-communicable diseases (NCD). Limited information exists about the prevalence of cardiometabolic risk factors and the burden of cardiovascular disease (CVD) in the adult Nigerian population, especially in the rural setting. The aim of this study was to assess and describe the prevalence of several cardiometabolic risk factors in the sub-Saharan adult population of a rural Yoruba community, living in south-western Nigeria. The study was a descriptive, cross-sectional, random-sample survey. Participants were visited at home by trained nurses and community health extension workers (CHEW) who administered a questionnaire, took the relevant history, carried out clinical examinations and measurements and took samples for laboratory tests. They were supervised by primary healthcare physicians serving the community. The variables recorded comprised clinical history, CVD risk factors including blood pressure (BP), body mass index (BMI), waist circumference, blood sugar and serum lipid levels, cigarette use, and dietary habits. The participants included 2 000 healthy adults aged 18 to 64 years who had been living in the area for more than three years. The average age was 42.1 +/- 21.6, with 43.7% (873) being males and 56.3% (1127) females; 20.8% were hypertensive with BP > or = 140/90 mmHg, 42.3% of the men and 36.8% of the women had BP > or = 130/85 mmHg; 2.5% had diabetes, 1.9% had hypertriglycerideaemia, 43.1% had low HDL-C, 3.9% had general obesity, 14.7% had abdominal obesity, 3.2% were physically inactive, and 1.7% smoked cigarettes. Overall, 12.9% of the subjects were found to have at least one CVD risk factor. Using the Adult Treatment Panel (ATP) III criteria, 2.1% of men and 2.7% of women in the study population had at least three of the criteria, the commonest being HDL-C or = 130/85 mmHg, then waist circumference > 88 cm in women or

  15. Ethnobotanical survey of Rinorea dentata (Violaceae) used in South-Western Nigerian ethnomedicine and detection of cyclotides.

    Science.gov (United States)

    Attah, Alfred F; Hellinger, Roland; Sonibare, Mubo A; Moody, Jones O; Arrowsmith, Sarah; Wray, Susan; Gruber, Christian W

    2016-02-17

    People living in the tropical rain forest of South-Western Nigeria use Rinorea dentata (P. Beauv.) Kuntze (Violaceae) in ethno-veterinary medicine to facilitate parturition. There are no evidence-based pharmacological investigations for the uterotonic activity of this plant. (i) Collection of data about the ethnopharmacological uses of R. dentata and evaluation of its uses and applications in health care; (ii) determining potential uterotonic effects in vitro, and (iii) chemical characterization of R. dentata, which is a member of the Violaceae family known to express circular cystine-knot peptides, called cyclotides. The ethnopharmacological use of R. dentata in settlement camps within the area J4 of Omo forest has been investigated by semi-structured questionnaires and open interviews. Use index analysis has been performed by seven quantitative statistical models. Respondents' claim on the beneficial ethno-veterinary application of the plant to aid parturition has been investigated in vitro by myometrial contractility organ bath assays. The bioactive plant extract was screened by chemical derivatization and mass spectrometry-based peptidomics using reversed-phase HPLC fractionation and MALDI-TOF/TOF analysis. Based on the survey analysis, medicinal preparations of R. dentata have been used for anti-microbial and anti-malaria purpose in humans, and for aiding parturition in farm animals. The latter application was mentioned by one out of six respondents who claimed to use this plant for any medicinal purpose. The plant extract exhibited a weak uterotonic effect using organ bath studies. The plant contains cyclotides and the peptide riden A has been identified by de novo amino acid sequencing using mass spectrometry. Few dwellers around the settlement camps of the tropical forest of Omo (Nigeria) use R. dentata for various health problems in traditional veterinary and human medicine. The weak uterotonic effect of the cyclotide-rich extract is in agreement with the

  16. The diversity of benthic mollusks of Lake Victoria and Lake Burigi ...

    African Journals Online (AJOL)

    Molluscan diversity, abundance and distribution in sediments of Lake Victoria and its satellite lake, Lake Burigi, were investigated. The survey was carried out ... Melanoides tuberculata and Biomphalaria chaonomphala were the only two gastropods represented and widely distributed in the two lakes. Bivalvia constituting of ...

  17. Lake Erie Fish Community Data, 2013 - 2016

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Lake Erie Biological Station (LEBS), located in Sandusky, Ohio, is a field station of the USGS Great Lakes Science Center (GLSC). LEBS is the primary federal agency...

  18. Holocene climatic variations and postglacial sea-level rise geochemically recorded in the sediments of the brackish karst lake An Loch Mór, western Ireland

    OpenAIRE

    Georg Schettler; Romer, R. L.; M. O'Connell; Molloy, K.

    2006-01-01

    Palaeohydrology of the brackish karst lake An Loch Mór (Inis Oírr) was reconstructed based on its 11 600 year sedimentation record. Low calcareous early Holocene sediments, characterized by high TOC contents and deposited at generally low accumulation rates, show a gradual decrease upwards in the concentration of the siliciclastic sediment until c. 7000 cal. yr BP. From c. 9000 cal. yr BP, sediment accumulation became increasingly dominated by the deposition of autochthonous calcite and organ...

  19. A Water Quality Survey of Nutrient Loadings to Center Hill Lake from the Caney Fork River Basin

    Science.gov (United States)

    1989-08-01

    by heterotrophic bacteria and algae, resulting in a reduction of pH. High pH values in the photic zone of Center Hill Lake indicate fairly high...ecological succession of microorganisms: aerobic heterotrophs, denitrifiers, fermentators, sulfate reducers, to methane bacteria " [Stumm and Morgan...input into natural waters can effectively limit the growth of the nitrogen-fixing blue greens, such as Anabaena, Gloeotrichia and Nostoc , etc." 66. The

  20. Linking carbon and nitrogen metabolism to depth distribution of submersed macrophytes using high ammonium dosing tests and a lake survey.

    Science.gov (United States)

    Yuan, Guixiang; Cao, Te; Fu, Hui; Ni, Leyi; Zhang, Xiaolin; Li, Wei; Song, Xin; Xie, Ping; Jeppesen, Erik

    2013-12-01

    Strategies of carbon (C) and nitrogen (N) utilisation are among the factors determining plant distribution. It has been argued that submersed macrophytes adapted to lower light environments are more efficient in maintaining C metabolic homeostasis due to their conservative C strategy and ability to balance C shortage. We studied how depth distributions of 12 submersed macrophytes in Lake Erhai, China, were linked to their C-N metabolic strategies when facing acute [Formula: see text] dosing.[Formula: see text] dosing changed C-N metabolism significantly by decreasing the soluble carbohydrate (SC) content and increasing the [Formula: see text]-N and free amino acid (FAA) content of plant tissues.The proportional changes in SC contents in the leaves and FAA contents in the stems induced by [Formula: see text] dosing were closely correlated (positive for SC and negative for FAA) with the colonising water depths of the plants in Lake Erhai, the plants adapted to lower light regimes being more efficient in maintaining SC and FAA homeostasis.These results indicate that conservative carbohydrate metabolism of submersed macrophytes allowed the plants to colonise greater water depths in eutrophic lakes, where low light availability in the water column diminishes carbohydrate production by the plants.

  1. From Study to Work: Methodological Challenges of a Graduate Destination Survey in the Western Cape, South Africa

    Science.gov (United States)

    du Toit, Jacques; Kraak, Andre; Favish, Judy; Fletcher, Lizelle

    2014-01-01

    Current literature proposes several strategies for improving response rates to student evaluation surveys. Graduate destination surveys pose the difficulty of tracing graduates years later when their contact details may have changed. This article discusses the methodology of one such a survey to maximise response rates. Compiling a sample frame…

  2. HYDROLOGY OF COASTAL WETLANDS OF LAKE SUPERIOR: LAKE AND TRIBUTARY ROLES IN MIXING REGIME AND TURNOVER TIMES

    Science.gov (United States)

    Our work on coastal wetlands of western Lake Superior indicates that hydrological linkages to the lake and watershed are highly dynamic, with potentially significant implications for wetland ecosystem structure and function. Time series data on tributary discharges and seiche amp...

  3. Killer whale surveys conducted in the Aleutian Islands, Bering Sea, and western and central Gulf of Alaska by Alaska Fisheries Science Center, National Marine Mammal Laboratory from 2001-07-01 to 2010-07-12 (NCEI Accession 0137766)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is a compilation of line-transect data collected on surveys in the Aleutian Islands, Bering Sea, and western and central Gulf of Alaska, 2001 - 2010....

  4. Aerial gamma ray and magnetic survey, Mississippi and Florida airborne survey: Lake Charles and Port Arthur quadrangles of Louisiana and Texas. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-10-01

    The Lake Charles and Port Arthur quadrangles cover approximately 10,950 square miles of land west of the Mississippi River delta area. The area overlies thick sections of the Gulf of Mexico Basin. Surficial exposures are dominated by Recent and Pleistocene sediment. A search of available literature revealed no known uranium deposits. A total of 82 uranium anomalies were detected and are discussed briefly in this report. None were considered significant and all appear to relate to cultural features. Magnetic data appear to be in agreement with existing structural interpretations of the area.

  5. Genetic structure of lake whitefish, Coregonus clupeaformis, populations in the northern main basin of Lake Huron

    Science.gov (United States)

    Stott, Wendylee; Ebener, Mark P.; Mohr, Lloyd; Schaeffer, Jeff; Roseman, Edward F.; Harford, William J.; Johnson, James E.; Fietsch, Cherie-Lee

    2012-01-01

    Genetic analysis of spawning lake whitefish (Coregonus clupeaformis) from six sites in the main basin of Lake Huron was conducted to determine population structure. Samples from fisheryindependent assessment surveys in the northwest main basin were analyzed to determine the relative contributions of lake whitefish genetic populations. Genetic population structure was identified using data from seven microsatellite DNA loci. One population was identified at Manitoulin Island, one to two were observed in the east-central main basin (Fishing Island and Douglas Point), and one to two populations were found in the northwest (Thunder Bay and Duncan Bay). The genetic identity of collections from Duncan Bay and Thunder Bay was not consistent among methods used to analyze population structure. Low genetic distances suggested that they comprised one population, but genic differences indicated that they may constitute separate populations. Simulated data indicated that the genetic origins of samples from a mixed-fishery could be accurately identified, but accuracy could be improved by incorporating additional microsatellite loci. Mixture analysis and individual assignment tests performed on mixed-stock samples collected from the western main basin suggested that genetic populations from the east-central main basin contributed less than those from the western main basin and that the proportional contribution of each baseline population was similar in each assessment sample. Analysis of additional microsatellite DNA loci may be useful to help improve the precision of the estimates, thus increasing our ability to manage and protect this valuable resource.

  6. Thaw /thermokarst lakes of the Last Galcial and Early Holocene

    Science.gov (United States)

    van Huissteden, Ko

    2013-04-01

    Thaw (thermokarst) lakes have attracted attention as major sources of CH4, amplifying climate change. Also during the Last Glacial thaw lake sedimentary successions have been deposited; several lacustrine units in sedimentary successions in Western Europe have been attributed to permafrost thaw. Likewise, rapid expansion of thaw lakes has occurred during the last glacial termination, in particular in high northern areas of the Eurasian continent. This suggests that also during the Last Glacial, thaw lake formation and associated methane emission from permafrost may have been a positive feedback to climate warming. In this paper, the sedimentological evidence for past thaw lake formation is assessed and compared with thaw lakes and thaw depressions observed in Eastern Siberia. Several of the Western European successions that are interpreted as thaw lakes may have been rather shallow permafrost thaw features instead of lakes, although larger thaw lakes did exist. In several successions, lake and thaw depression formation could be associated with climate warming during interstadials. The sedimentological evidence is also compared with present-day thaw lake dynamics.The evidence on present-day thaw lake expansion is mixed despite pronounced climate warming in the Arctic, and shows stability, net contraction or expansion of lake area in various regions. The evidence may also differ with lake size: net expansion for smaller lakes and ponds, while the area of larger lakes contracts due to drainage of larger lakes. The assumed existence of a thaw lake cycle, that consists of a repeating cycle of lake formation by permafrost thaw, drainage of lakes and re-establishment of ice-rich permafrost, is crucial in the interpretation of lake area changes as an effect of climate change. The thaw lake cycle implies that expansion or contraction of thaw lake area may not necessarily relate to climate change. However, the existance of a thaw lake cycle is inconclusive, although modeling

  7. Polycyclic aromatic hydrocarbons (PAHs) in sediments from lake Lille Lungegårdsvannet in Bergen, western Norway; appraising pollution sources from the urban history.

    Science.gov (United States)

    Andersson, Malin; Klug, Martin; Eggen, Ola Anfin; Ottesen, Rolf Tore

    2014-02-01

    This study aims to determine the temporal character and concentration variability of polycyclic aromatic hydrocarbon (PAH) during the last 5,400 years in urban lake sediments through a combination of dating and chemo-stratigraphical correlation. We investigate the chemical history of the city of Bergen and determine the effect of specific point sources, as well as diffuse sources, and also help assess the risk of remediation plans. By using several organic compounds, metals and cyanide, we demonstrate the more accurate timing of sedimentation. The PAH results display very low concentrations in pre-industrial times, followed by a general increase that is punctuated by a few significant concentration increases. These most probably correspond to urban fires, domestic heating, gaswork activity and most recently due to traffic pollution. At the same depth as a significant rise in concentration from background levels occurred, the high relative occurrence of low-molecular-weight PAH-compounds, such as naphthalene, were replaced by heavier compounds, thus indicating a permanent change in source. The general observation, using ratios, is that the sources have shifted from pre-industrial pure wood and coal combustion towards mixed and petrogenic sources in more recent times. The (14)C dating provides evidence that the sedimentation rate stayed more-or-less constant for 4,500 years (from 7200 to 2700 calibrated years before present (calyr BP)), before isostatic uplift isolated the water body and the sedimentation rate decreased or sediments were eroded. The sediment input increased again when habitation and industrial activities encroached on the lake. The (14)C dating does not provide consistent data in that period, possibly due to the fact that the lake has been used as a waste site throughout the history of Bergen city. Therefore, results from (14)C dating from anthropogenically influenced sediments should be used with caution. © 2013.

  8. The Cora Lake Shear Zone: Strain Localization in an Ultramylonitic, Deep Crustal Shear Zone, Athabasca Granulite Terrain, Western Churchill Province, Canada

    Science.gov (United States)

    Regan, S.; Williams, M. L.; Mahan, K. H.; Orlandini, O. F.; Jercinovic, M. J.; Leslie, S. R.; Holland, M.

    2012-12-01

    Ultramylonitic shear zones typically involve intense strain localization, and when developed over large regions can introduce considerable heterogeneity into the crust. The Cora Lake shear zone (CLsz) displays several 10's to 100's of meters-wide zones of ultramylonite distributed throughout its full 3-5 km mylonitized width. Detailed mapping, petrography, thermobarometry, and in-situ monazite geochronology suggest that it formed during the waning phases of granulite grade metamorphism and deformation, within one of North America's largest exposures of polydeformed lower continental crust. Anastomosing zones of ultramylonite contain recrystallized grain-sizes approaching the micron scale and might appear to suggest lower temperature mylonitization. However, feldspar and even clinopyroxene are dynamically recrystallized, and quantitative thermobarometry of syn-deformational assemblages indicate high P and T conditions ranging from 0.9 -10.6 GPa and 775-850 °C. Even at these high T's, dynamic recovery and recrystallization were extremely limited. Rocks with low modal quartz have extremely small equilibrium volumes. This is likely the result of inefficient diffusion, which is further supported by the unannealed nature of the crystals. Local carbonate veins suggests that H2O poor, CO2 rich conditions may have aided in the preservation of fine grain sizes, and may have inhibited dynamic recovery and recrystallization. The Cora Lake shear zone is interpreted to have been relatively strong and to have hardened during progressive deformation. Garnet is commonly fractured perpendicular to host rock fabric, and statically replaced by both biotite and muscovite. Pseudotachylite, with the same sense of shear, occurs in several ultramylonitized mafic granulites. Thus, cataclasis and frictional melt are interpreted to have been produced in the lower continental crust, not during later reactivation. We suggest that strengthening of rheologically stiffer lithologies led to

  9. Determinants of Farmers’ Willingness to Pay and Its Level for Ecological Compensation of Poyang Lake Wetland, China: A Household-Level Survey

    Directory of Open Access Journals (Sweden)

    Fanbin Kong

    2014-09-01

    Full Text Available This study examines the determinants of farmers’ willingness to pay (WTP and their payment levels for ecological compensation of the Poyang Lake Wetland in China. We developed a farmer household survey and gathered 292 effective responses. The contingent valuation method (CVM and Heckman’s two-step model were employed for the empirical study. Results show that 46.58% of farmers are willing to pay ecological compensation, with an average price of $64.39/household per year. The influencing factors that significantly influence farmers’ WTP include household income, residential location, emphasis on improvement of wetland resources, arable land area, and contracted water area. In addition, household income, residential location, arable land area, and contracted water area are significantly related to their payment levels. The results of this empirical study inform important policy implications and recommendations.

  10. Great Salt Lake, Utah

    Science.gov (United States)

    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.

  11. Hydraulic, geomorphic, and trout habitat conditions of the Lake Fork of the Gunnison River in Hinsdale County, Lake City, Colorado, Water Years 2010-2011

    Science.gov (United States)

    Williams, Cory A.; Richards, Rodney J.; Schaffrath, Keelin R.

    2015-01-01

    Channel rehabilitation, or reconfiguration, to mitigate a variety of riverine problems has become a common practice in the western United States. However, additional work to monitor and assess the channel response to, and the effectiveness of, these modifications over longer periods of time (decadal or longer) is still needed. The Lake Fork of the Gunnison River has been an area of active channel modification to accommodate the needs of the Lake City community since the 1950s. The Lake Fork Valley Conservancy District began a planning process to assess restoration options for a reach of the Lake Fork in Lake City to enhance hydraulic and ecologic characteristics of the reach. Geomorphic channel form is affected by land-use changes within the basin and geologic controls within the reach. The historic channel was defined as a dynamic, braided channel with an active flood plain. This can result in a natural tendency for the channel to braid. A braided channel can affect channel stability of reconfigured reaches when a single-thread meandering channel is imposed on the stream. The U.S. Geological Survey, in cooperation with the Colorado Water Conservation Board and Colorado River Water Conservation District, began a study in 2010 to quantify existing hydraulic and habitat conditions for a reach of the Lake Fork of the Gunnison River in Lake City, Colorado. The purpose of this report is to quantify existing Lake Fork hydraulic and habitat conditions and establish a baseline against which post-reconfiguration conditions can be compared. This report (1) quantifies the existing hydraulic and geomorphic conditions in a 1.1-kilometer section of the Lake Fork at Lake City that has been proposed as a location for future channel-rehabilitation efforts, (2) characterizes the habitat suitability of the reach for two trout species based on physical conditions within the stream, and (3) characterizes the current riparian canopy density.

  12. Proceedings of the Western Regional Working Conference on "Ethnic Minorities and the Health Professions" (1st, Salt Lake City, Utah, March 23-25, 1976).

    Science.gov (United States)

    Western Interstate Commission for Higher Education, Boulder, CO.

    Sixty selected representatives from 13 western states, as well as other states throughout the U.S., gathered to share their concerns, exchange ideas, and demonstrate their unity for the continued expansion of the ethnic minority role within the health professions. Discussion centered on the degree of effectiveness of educational and governmental…

  13. Nurse prescribing of medicines in Western European and Anglo-Saxon countries: a survey on forces, conditions and jurisdictional control.

    NARCIS (Netherlands)

    Kroezen, M.; Francke, A.L.; Groenewegen, P.P.; Dijk, L. van

    2012-01-01

    Background: The number of Western European and Anglo-Saxon countries where nurses are legally allowed to prescribe medicines is growing. As the prescribing of medicines has traditionally been the task of the medical profession, nurse prescribing is changing the relationship between the medical and

  14. Nurse prescribing of medicines in Western European and Anglo-Saxon countries: a survey on forces, conditions and jurisdictional control

    NARCIS (Netherlands)

    Kroezen, M.; Francke, A.L.; Groenewegen, P.P.; van Dijk, L.

    2012-01-01

    Background: The number of Western European and Anglo-Saxon countries where nurses are legally allowed to prescribe medicines is growing. As the prescribing of medicines has traditionally been the task of the medical profession, nurse prescribing is changing the relationship between the medical and

  15. Foraging and predation risk for larval cisco (Coregonus artedi) in Lake Superior: a modelling synthesis of empirical survey data

    Science.gov (United States)

    Myers, Jared T.; Yule, Daniel L.; Jones, Michael L.; Quinlan, Henry R.; Berglund, Eric K.

    2014-01-01

    The relative importance of predation and food availability as contributors to larval cisco (Coregonus artedi) mortality in Lake Superior were investigated using a visual foraging model to evaluate potential predation pressure by rainbow smelt (Osmerus mordax) and a bioenergetic model to evaluate potential starvation risk. The models were informed by observations of rainbow smelt, larval cisco, and zooplankton abundance at three Lake Superior locations during the period of spring larval cisco emergence and surface-oriented foraging. Predation risk was highest at Black Bay, ON, where average rainbow smelt densities in the uppermost 10 m of the water column were >1000 ha−1. Turbid conditions at the Twin Ports, WI-MN, affected larval cisco predation risk because rainbow smelt remained suspended in the upper water column during daylight, placing them alongside larval cisco during both day and night hours. Predation risk was low at Cornucopia, WI, owing to low smelt densities (cisco survival at Black Bay and to a lesser extent at Twin Ports, and that starvation may be a major source of mortality at all three locations. The framework we describe has the potential to further our understanding of the relative importance of starvation and predation on larval fish survivorship, provided information on prey resources available to larvae are measured at sufficiently fine spatial scales and the models provide a realistic depiction of the dynamic processes that the larvae experience.

  16. Tobacco sales in pharmacies: a survey of attitudes, knowledge and beliefs of pharmacists employed in student experiential and other worksites in Western New York

    Directory of Open Access Journals (Sweden)

    Smith Danielle M

    2012-08-01

    Full Text Available Abstract Background Pharmacies are venues in which patients seek out products and professional advice in order to improve overall health. However, many pharmacies in the United States continue to sell tobacco products, which are widely known to cause detrimental health effects. This conflict presents a challenge to pharmacists, who are becoming increasingly more involved in patient health promotion activities. This study sought to assess Western New York (WNY area pharmacists’ opinions about the sale of tobacco products in pharmacies, and pharmacists’ opinions on their role in patient smoking cessation. Methods Participants responded to two parallel surveys; a web-based survey was completed by 148 university-affiliated pharmacist preceptors via a list based sample, and a mail-based survey was completed by the supervising pharmacist in 120 area pharmacies via a list-based sample. The combined response rate for both surveys was 31%. Univariate and bivariate analyses were performed to determine any significant differences between the preceptor and supervising pharmacist survey groups. Results Over 75% of respondents support legislation banning the sale of tobacco products in pharmacies. Over 86% of respondents would prefer to work in a pharmacy that does not sell tobacco products. Differences between preceptor and supervising pharmacist groups were observed. Action regarding counseling patients was uncommon among both groups. Conclusions Pharmacists support initiatives that increase their role in cessation counseling and initiatives that restrict the sale of tobacco products in pharmacies. These data could have important implications for communities and pharmacy practice.

  17. Archeological Survey and Testing at Pomme de Terre and Stockton Lakes, Cedar, Dade, Hickory, and Polk Counties, Missouri

    Science.gov (United States)

    1992-01-01

    into the continental interior of eastern North America, giving time for evolution of greater environmental tolerance and the addition of gardening to a...an individual named John Birdsong who may or may not have actually owned the property. Portions of Sec- tion 21 were claimed by the 1850s (The...the various building elements and the evolution of a typical western Ozarks farmstead over a period of more than 100 years. It is recommended that

  18. Eyelash Epilation in the Absence of Trichiasis: Results of a Population-Based Prevalence Survey in the Western Division of Fiji

    Science.gov (United States)

    Butcher, Robert; Mudaliar, Umesh; Natutusau, Kinisimere; Rainima-Qaniuci, Mere; Haffenden, Chris; Watson, Conall; Cocks, Naomi; Cikamatana, Luisa; Roberts, Chrissy H.; Marks, Michael; Rafai, Eric; Mabey, David C. W.; Kama, Mike; Solomon, Anthony W.

    2017-01-01

    Background The WHO definition of trachomatous trichiasis (TT) is “at least one eyelash touching the globe, or evidence of recent epilation of in-turned eyelashes”, reflecting the fact that epilation is used as a self-management tool for TT. In Fiji’s Western Division, a high TT prevalence (8.7% in those aged ≥15 years) was reported in a 2012 survey, yet a 2013 survey found no TT and Fijian ophthalmologists rarely see TT cases. Local anecdote suggests that eyelash epilation is a common behaviour, even in the absence of trichiasis. Epilators may have been identified as TT cases in previous surveys. Methods We used a preliminary focus group to design an interview questionnaire, and subsequently conducted a population-based prevalence survey to estimate the prevalence of epilation in the absence of trichiasis, and factors associated with this behaviour, in the Western Division of Fiji. Results We sampled 695 individuals aged ≥15 years from a total of 457 households in 23 villages. 125 participants (18%) reported epilating their eyelashes at least once within the past year. Photographs were obtained of the eyes of 121/125 (97%) individuals who epilated, and subsequent analysis by an experienced trachoma grader found no cases of trachomatous conjunctival scarring or trichiasis. The age- and sex- adjusted prevalence of epilation in those aged ≥15 years was 8.6% (95% CI 5.7–11.3%). iTaukei ethnicity, female gender, and a higher frequency of drinking kava root were independently associated with epilation. Conclusion Epilation occurs in this population in the absence of trichiasis, with sufficient frequency to have markedly inflated previous estimates of local TT prevalence. Individuals with epilated eyelashes should be confirmed as having epilated in-turned eyelashes in an eye with scarring of the conjunctiva before being counted as cases of TT. PMID:28114364

  19. Eyelash Epilation in the Absence of Trichiasis: Results of a Population-Based Prevalence Survey in the Western Division of Fiji.

    Directory of Open Access Journals (Sweden)

    Colin Macleod

    2017-01-01

    Full Text Available The WHO definition of trachomatous trichiasis (TT is "at least one eyelash touching the globe, or evidence of recent epilation of in-turned eyelashes", reflecting the fact that epilation is used as a self-management tool for TT. In Fiji's Western Division, a high TT prevalence (8.7% in those aged ≥15 years was reported in a 2012 survey, yet a 2013 survey found no TT and Fijian ophthalmologists rarely see TT cases. Local anecdote suggests that eyelash epilation is a common behaviour, even in the absence of trichiasis. Epilators may have been identified as TT cases in previous surveys.We used a preliminary focus group to design an interview questionnaire, and subsequently conducted a population-based prevalence survey to estimate the prevalence of epilation in the absence of trichiasis, and factors associated with this behaviour, in the Western Division of Fiji.We sampled 695 individuals aged ≥15 years from a total of 457 households in 23 villages. 125 participants (18% reported epilating their eyelashes at least once within the past year. Photographs were obtained of the eyes of 121/125 (97% individuals who epilated, and subsequent analysis by an experienced trachoma grader found no cases of trachomatous conjunctival scarring or trichiasis. The age- and sex- adjusted prevalence of epilation in those aged ≥15 years was 8.6% (95% CI 5.7-11.3%. iTaukei ethnicity, female gender, and a higher frequency of drinking kava root were independently associated with epilation.Epilation occurs in this population in the absence of trichiasis, with sufficient frequency to have markedly inflated previous estimates of local TT prevalence. Individuals with epilated eyelashes should be confirmed as having epilated in-turned eyelashes in an eye with scarring of the conjunctiva before being counted as cases of TT.

  20. Eyelash Epilation in the Absence of Trichiasis: Results of a Population-Based Prevalence Survey in the Western Division of Fiji.

    Science.gov (United States)

    Macleod, Colin; Yalen, Chelsea; Butcher, Robert; Mudaliar, Umesh; Natutusau, Kinisimere; Rainima-Qaniuci, Mere; Haffenden, Chris; Watson, Conall; Cocks, Naomi; Cikamatana, Luisa; Roberts, Chrissy H; Marks, Michael; Rafai, Eric; Mabey, David C W; Kama, Mike; Solomon, Anthony W

    2017-01-01

    The WHO definition of trachomatous trichiasis (TT) is "at least one eyelash touching the globe, or evidence of recent epilation of in-turned eyelashes", reflecting the fact that epilation is used as a self-management tool for TT. In Fiji's Western Division, a high TT prevalence (8.7% in those aged ≥15 years) was reported in a 2012 survey, yet a 2013 survey found no TT and Fijian ophthalmologists rarely see TT cases. Local anecdote suggests that eyelash epilation is a common behaviour, even in the absence of trichiasis. Epilators may have been identified as TT cases in previous surveys. We used a preliminary focus group to design an interview questionnaire, and subsequently conducted a population-based prevalence survey to estimate the prevalence of epilation in the absence of trichiasis, and factors associated with this behaviour, in the Western Division of Fiji. We sampled 695 individuals aged ≥15 years from a total of 457 households in 23 villages. 125 participants (18%) reported epilating their eyelashes at least once within the past year. Photographs were obtained of the eyes of 121/125 (97%) individuals who epilated, and subsequent analysis by an experienced trachoma grader found no cases of trachomatous conjunctival scarring or trichiasis. The age- and sex- adjusted prevalence of epilation in those aged ≥15 years was 8.6% (95% CI 5.7-11.3%). iTaukei ethnicity, female gender, and a higher frequency of drinking kava root were independently associated with epilation. Epilation occurs in this population in the absence of trichiasis, with sufficient frequency to have markedly inflated previous estimates of local TT prevalence. Individuals with epilated eyelashes should be confirmed as having epilated in-turned eyelashes in an eye with scarring of the conjunctiva before being counted as cases of TT.

  1. Reconstructed Depositional Environment and Climate Record of Western North America Over the Past 25,000 Years from Tulare Lake, South-Central California

    Science.gov (United States)

    Mohammadi, O.; Wehunt, K.; Chumpitaz, G. A.; Bravo, B.; Ruiz, J.; Dhesi, H.; Halling, M. C.; Pyles, C. G.; Guo, J.; Negrini, R. M.

    2016-12-01

    Tulare Lake, located in the southern San Joaquin Valley, California has been the site of repeated geologic and paleoclimate studies due to its well preserved sedimentary record based on core, trench exposures, and the mapping of geomorphic features. Yet, no studies have focused on the effect of depositional environment variations on mineralogy. In this study, a series of integrated geochemical, sedimentary, and grain-size climate proxy data from core TL05-4A encompassing the last 25 cal. ka BP were analyzed. Preliminary sedimentary results as determined by X-ray diffraction (XRD) reveal a clay-dominant mineral assemblage containing variable smectite, illite, kaolinite, and chlorite followed by a secondary non-clay contribution in the form of quartz, feldspar, and calcite. The relative abundance of these minerals varies with depth and is tied to regional shifts in climate as best exemplified by an observed rapid increase in bulk clay percentages (+50%) after the Tioga deglaciation event ( 14 cal. ka BP). Six climosequences were determined—three wet periods interspaced by three dry episodes over the last 25 ka. Two important dry periods characterized by gypsum and bassanite occurred from 10.7-9.4 cal. ka BP (Preboreal warming) and 8.2-5.2 cal. ka BP (Holocene Climate Optimum) indicating oxygen depletion, more intense evaporation, and reducing conditions in the lake. These abrupt dry phases may help explain the geographic range reduction and extirpation of Mammuthus primigenius and other North American megafanua as warmer and dryer regional conditions led to enhanced water stress and diminished net primary productivity.

  2. Stratigraphic evidence for the role of lake spillover in the inception of the lower Colorado River in southern Nevada and western Arizona

    Science.gov (United States)

    House, P.K.; Pearthree, P.A.; Perkins, M.E.

    2008-01-01

    Late Miocene and early Pliocene sediments exposed along the lower Colorado River near Laughlin, Nevada, contain evidence that establishment of this reach of the river after 5.6 Ma involved flooding from lake spillover through a bedrock divide between Cottonwood Valley to the north and Mohave Valley to the south. Lacustrine marls interfingered with and conformably overlying a sequence of post-5.6 Ma finegrained valley-fill deposits record an early phase of intermittent lacustrine inundation restricted to Cottonwood Valley. Limestone, mud, sand, and minor gravel of the Bouse Formation were subsequently deposited above an unconformity. At the north end of Mohave Valley, a coarse-grained, lithologically distinct fluvial conglomerate separates subaerial, locally derived fan deposits from subaqueous deposits of the Bouse Formation. We interpret this key unit as evidence for overtopping and catastrophic breaching of the paleodivide immediately before deep lacustrine inundation of both valleys. Exposures in both valleys reveal a substantial erosional unconformity that records drainage of the lake and predates the arrival of sediment of the through-going Colorado River. Subsequent river aggradation culminated in the Pliocene between 4.1 and 3.3 Ma. The stratigraphic associations and timing of this drainage transition are consistent with geochemical evidence linking lacustrine conditions to the early Colorado River, the timings of drainage integration and canyon incision on the Colorado Plateau, the arrival of Colorado River sand at its terminus in the Salton Trough, and a downstream-directed mode of river integration common in areas of crustal extension. ?? 2008 The Geological Society of America.

  3. A preliminary survey of the freshwater mussels of the Bayfield River watershed and nearby Lake Huron tributaries.

    National Research Council Canada - National Science Library

    Morris, T; McNichols-O'Rourke, K; Robinson, A

    2012-01-01

    .... A total of 1385 animals were found, representing 16 species. The dominant species in the Bayfield River watershed was Pyganodon grandis, which occurred at over half of the sites surveyed, and represented 44...

  4. An archaeological survey of a borrow area within the Fish Springs National Wildlife Refuge in western Utah

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report provides information from an archeological survey conducted on the north section of the Fish Springs National Wildlife Refuge. The Office of Public...

  5. Second-Year Results from the Circumarctic Lakes Observation Network (CALON) Project

    Science.gov (United States)

    Hinkel, K. M.; Arp, C. D.; Beck, R. A.; Eisner, W. R.; Frey, K. E.; Gaglioti, B.; Grosse, G.; Jones, B. M.; Kim, C.; Lenters, J. D.; Liu, H.; Townsend-Small, A.

    2013-12-01

    Beginning in April 2012, over 55 lakes in northern Alaska were instrumented as the initial phase of CALON, a project designed to document landscape-scale variability in physical and biogeochemical processes of Arctic lakes developed atop permafrost. The current network has nine observation nodes along two latitudinal transects that extend from the Arctic Ocean south 200 km to the foothills of the Brooks Range. At each node, six representative lakes of differing area and depth were instrumented at different intensity levels, and a suite of instruments were deployed to collect field measurements on lake physiochemistry, lake-surface and terrestrial climatology, and lake bed and permafrost temperature. Each April, sensors measuring water temperature and water depth are deployed through the ice and water samples are collected. Sensors are downloaded from lakes and meteorological stations in August, recording a timeline of lake regimes and events from ice decay to the summertime energy and water balance. In general, lake ice thickness increased with latitude. In 2012, ice on deeper (>2 m) lakes was about 1.4 m thick in the Arctic Foothills and 1.7 m thick near the Arctic Ocean coast. Lake ice thickness was about 20 cm thicker in winter 2013 although winter temperatures were several degrees warmer than the previous year; this is likely due to a thinner snow cover in 2013. Lake ice elevations agree with this general trend, showing higher absolute elevation in April 2013 compared to 2012 for most of the surveyed lakes. Regionally, ice-off occurs 2-4 weeks later on lakes near the coast, although there is significant inter-lake variability related to lake depth. Following ice-off, rapid lake warming occurs and water temperature varies synchronously in response to synoptic weather variations and associated changes in net radiation and turbulent heat fluxes. Average mid-summer (July) lake temperatures spanned a relatively wide range in 2012 from 7°C to 18°C, with higher

  6. Validating a hospital medicines formulary survey in the Western Pacific Region--a global hospital pharmacy initiative based on the Basel Statements.

    Science.gov (United States)

    Penm, Jonathan; Chaar, Betty; Moles, Rebekah

    2012-01-01

    In 2008, the Basel Statements were developed to reflect the future of hospital pharmacy worldwide. Included were a key set of statements regarding the expanding role of hospital pharmacists' influence on prescribing from the management of medicines formularies to being an active member of the therapeutic decision-making process. This study aimed to validate a survey to measure Basel Statement 26 regarding the role of medicines formularies and the factors that affect its use in the Western Pacific Region (WPR). The survey was developed in consultation with a WPR advisory group and current literature. The survey was translated using the forward-backward method into Chinese (simplified) and Vietnamese. The instrument was pilot tested in a stratified random sample of 260 hospital pharmacy directors in the WPR. Principal components analysis (PCA) was applied to the data to assess construct validity of the Medicines Formulary Scale that assessed responders' perceptions of their formulary and impact on utilization. The Medicines Formulary Survey was completed by 107 hospital pharmacy directors or equivalent. The survey contained the Medicines Formulary Scale in addition to questions regarding the content and review process of the hospital's formulary as well as demographic questions. Application of the PCA procedures resulted in a parsimonious 2-factor solution in which 33.8% of the variance was explained. The Cronbach alpha for the 17-item scale was found to be 0.70. The Cronbach alpha values for the first and second factor/subscales were 0.76 and 0.68, respectively. The Medicines Formulary Survey appears reliable and valid for assessing hospital pharmacy directors' perceptions of hospital medicine formularies in the WPR. Further development of validated instruments to assess other areas of hospital pharmacy practice will help track the progression of hospital pharmacy and aid in globalization of the profession. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. An evaluation of the zooplankton community at the Sheboygan River Area of Concern and non-Area of Concern comparison sites in western Lake Michigan rivers and harbors in 2016

    Science.gov (United States)

    Olds, Hayley T.; Scudder Eikenberry, Barbara C.; Burns, Daniel J.; Bell, Amanda H.

    2017-12-22

    The Great Lakes Areas of Concern (AOCs) are considered to be the most severely degraded areas within the Great Lakes basin, as defined in the Great Lakes Water Quality Agreement and amendments. Among the 43 designated AOCs are four Lake Michigan AOCs in the State of Wisconsin. The smallest of these AOCs is the Sheboygan River AOC, which was designated as an AOC because of sediment contamination from polychlorinated biphenyl compounds (PCBs), polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), and heavy metals. The Sheboygan River AOC has 9 of 14 possible Beneficial Use Impairments (BUIs), which must be addressed to improve overall water-quality, and to ultimately delist the AOC. One of the BUIs associated with this AOC is the “degradation of phytoplankton and zooplankton populations,” which can be removed from the list of impairments when it has been determined that zooplankton community composition and structure at the AOC do not differ significantly from communities at non-AOC comparison sites. In 2012 and 2014, the U.S. Geological Survey collected plankton (phytoplankton and zooplankton) community samples at the Sheboygan River AOC and selected non-AOC sites as part of a larger Great Lakes Restoration Initiative study evaluating both the benthos and plankton communities in all four of Wisconsin’s Lake Michigan AOCs. Although neither richness nor diversity of phytoplankton or zooplankton in the Sheboygan River AOC were found to differ significantly from the non-AOC sites in 2012, results from the 2014 data indicated that zooplankton diversity was significantly lower, and so rated as degraded, when compared to the Manitowoc and Kewaunee Rivers, two non-AOC sites of similar size, land use, and close geographic proximity.As a follow-up to the 2014 results, zooplankton samples were collected at the same locations in the AOC and non-AOC sites during three sampling trips in spring, summer, and fall 2016. An analysis of similarity indicated

  8. Economic impact of ticks and tick-borne diseases on cattle production systems around Lake Mburo National Park in South Western Uganda.

    Science.gov (United States)

    Ocaido, M; Muwazi, R T; Opuda, J Asibo

    2009-06-01

    A longitudinal economic impact study of Ticks and Tick-Borne Diseases (TTBDs) in cattle around Lake Mburo National Park (LMNP) was done. Impact was valued using Uganda Shilling (Ug. Shs) (exchange rate of 1USD to Ug. Shs 1,420). The costs for controlling TTBDs was constituting 85.6 +/- 3.2% (pastoral) and 73.8 +/- 4.2% (ranches) to total disease control costs. The main costs were on tick control, constituting 83.1% (ranches) and 87.9% (pastoral). In pastoral herds, the costs were negatively correlated to herd size (r = -0.99). The mean annual cost per cattle for controlling TTBDs for ranch and pastoral herds was similar Ug. Shs 5,900 +/- 545. The mean annual Economic Cost (EC) of TTBDs per cattle was not significantly different (p > 0.05) between pastoral (Ug. Shs 6,700 +/- 580) and ranch herds (Ug. Shs 7,600 +/- 970). The mean annual EC per cattle was negatively correlated (r = -0.99) with herd size in pastoral systems contrary to positive correlation (r = 0.99) observed among the ranches. The major component of EC of TTBDs of 88.2% (pastoral) and 78.6% (ranches) was due to their control. The other component was owed to mortality, which was positively correlated (p < 0.01) to the ranch herd size. The total annual EC of TTBDs around LMNP was Ug. Shs 437,754,600 (USD 308,144).

  9. Palynology of Late Pleistocene varved clays from ice-dammed lakes at Lębork and Złocieniec (north-western Poland) - preliminary results

    Science.gov (United States)

    Gedl, Przemysław

    2011-04-01

    Samples collected from Late Pleistocene varved clays of the Vistulian (Weichselian) glaciation exposed at Lębork and Złocieniec (Gardno and Pomeranian phases, respectively) yielded palynological contents that are related to the different lithologies composing the varves. The dark-coloured clay units contain very small amounts of palynological material. The lighter-coloured, much thicker coarser units yielded large amounts of organic particles consisting of predominantly palynodebris of terrestrial plants, sporomorphs and aquatic palynomorphs. The latter include fresh-water and marine phytoplankton. All particles were presumably washed out from the pre-Quaternary basement or from erratic material. This is indicated by the dinoflagellate-cyst assemblages, which represent Cretaceous and Palaeogene taxa. The large amounts of organic particles in the light-coloured layers indicate high-energy meltwaters streams, which washed them out, transported them and deposited them in ice-dammed lakes. The barren layers and those with lower amounts of organic particles were deposited during calm, presumably winter, periods, when the energy of the meltwater streams was much lower.

  10. A survey of Enterobius vermicularis infection among children on western and southern coastal islands of the Republic of Korea

    Science.gov (United States)

    Park, Jae-Hwan; Han, Eun-Taek; Kim, Won-Hee; Shin, Eun-Hee; Guk, Sang-Mee; Kim, Jae-Lip

    2005-01-01

    To determine the status of Enterobius vermicularis infection among children living on western and southern coastal islands of the Republic of Korea, children (3-10 years) in 39 kindergartens and primary schools were examined using the cello-tape anal swab method, during July and August 2000. Of 1,661 children examined, 307 (18.5%) were found to be positive for E. vermicularis eggs. The highest infection rate (59.3%) was found in a kindergarten and a branch school of Shinyang primary school on Chujado, Jeju-do (Province). Remarkable differences in egg positive rates were observed in different localities. The egg positive rate for boys (21.3%) was significantly higher than that of girls (15.4%) (P = 0.02). However, positive rates were not significantly dependent on age. The results of the present study show that E. vermicularis infection is highly prevalent among pre-school and primary school children living on the western and southern coastal islands of the Republic of Korea, and indicate the need for efforts to control this infection. PMID:16340301

  11. Emergency satellite observation and assessment of a glacier lake outburst flood in Bhutan

    Science.gov (United States)

    Nagai, Hiroto; Tadono, Takeo; Suzuki, Shinichi

    2016-04-01

    Following a glacial lake outburst flood (GLOF) on Jun. 28, 2015, in western Bhutan, the Japan Aerospace Exploration Agency performed an emergency observation on Jul. 2, 2015 using the Phased Array type L-band Synthetic Aperture Radar-2 (PALSAR-2) onboard the Advanced Land Observing Satellite-2 (ALOS-2, "DAICHI-2"). Based on a dataset generated from the Advanced Land Observing Satellite (ALOS) imagery, "The Glacial Lake Inventory of Bhutan using ALOS Data", the glacier lake that potentially contributed to this GLOF were identified at 28°4'7.7"N, 89°34'50.0"E, in a headwater of the Mo Chu river basin, western Bhutan. A post-event lake outline was delineated manually using the acquired PALSAR-2 image. Pre-event outlines were delineated from previously acquired PALSAR-2 images (Apr. 23, 2015), Landsat 8 (Mar. 8, 2015), and ALOS (Dec. 22, 2010). The differences between these outlines reveal a remarkable expansion (+48.0%) from Mar. 8 to Apr. 23, 2015, followed by a remarkable shrinkage (-52.9%) from Apr. 23 to Jul. 2, 2015. This result indicates the lake to be a highly likely source of the flood. Topographically, it is located at a glacier terminus, surrounded by a moraine. Differing backscatter patterns between successive PALSAR-2 images in a certain part of the moraine suggest that it underwent some collapse, possibly as a result of the GLOF. More detailed investigations, including field surveys, are necessary to fully reveal and understand this event.

  12. Lake Cadagno

    DEFF Research Database (Denmark)

    Tonolla, Mauro; Storelli, Nicola; Danza, Francesco

    2017-01-01

    Lake Cadagno (26 ha) is a crenogenic meromictic lake located in the Swiss Alps at 1921 m asl with a maximum depth of 21 m. The presence of crystalline rocks and a dolomite vein rich in gypsum in the catchment area makes the lake a typical “sulphuretum ” dominated by coupled carbon and sulphur cyc...

  13. LiDAR-guided Archaeological Survey of a Mediterranean Landscape: Lessons from the Ancient Greek Polis of Kolophon (Ionia, Western Anatolia).

    Science.gov (United States)

    Grammer, Benedikt; Draganits, Erich; Gretscher, Martin; Muss, Ulrike

    2017-01-01

    In 2013, an airborne laser scan survey was conducted in the territory of the Ionian city of Kolophon near the western coast of modern Turkey as part of an archaeological survey project carried out by the Mimar Sinan University of Istanbul (Turkey) and the University of Vienna (Austria). Several light detection and ranging (LiDAR) studies have been carried out in the temperate climate zones of Europe, but only a few in Mediterranean landscapes. Our study is based on the first LiDAR survey carried out for an archaeological purpose in Turkey and one of the first in the Mediterranean that have been planned, measured and filtered especially for archaeological research questions. The interpretation of LiDAR data combined with ground-observations proved extremely useful for the detection and documentation of archaeological remains below Mediterranean evergreen vegetation and dense maquis. This article deals with the methodological aspects of interpreting LiDAR data, using the Kolophon data as a case study. We offer a discussion of the strengths and limitations of LiDAR as an archaeological remote sensing method and suggest a best practice model for interpreting LiDAR data in a Mediterranean context. © 2017 The Authors. Archaeological Prospection published by John Wiley & Sons Ltd.

  14. Magnetic resonance sounding survey data collected in the North Platte, Twin Platte, and South Platte Natural Resource Districts, Western Nebraska, Fall 2012

    Science.gov (United States)

    Kass, Mason A.; Bloss, Benjamin R.; Irons, Trevor P.; Cannia, James C.; Abraham, Jared D.

    2014-01-01

    This report is a release of digital data and associated survey descriptions from a series of magnetic resonance soundings (MRS, also known as surface nuclear magnetic resonance) that was conducted during October and November of 2012 in areas of western Nebraska as part of a cooperative hydrologic study by the North Platte Natural Resource District (NRD), South Platte NRD, Twin Platte NRD, the Nebraska Environmental Trust, and the U.S. Geological Survey (USGS). The objective of the study was to delineate the base-of-aquifer and refine the understanding of the hydrologic properties in the aquifer system. The MRS technique non-invasively measures water content in the subsurface, which makes it a useful tool for hydrologic investigations in the near surface (up to depths of approximately 150 meters). In total, 14 MRS production-level soundings were acquired by the USGS over an area of approximately 10,600 square kilometers. The data are presented here in digital format, along with acquisition information, survey and site descriptions, and metadata.

  15. Prevalence of dyslipidaemia and associated risk factors in a rural population in South-Western Uganda: a community based survey.

    Directory of Open Access Journals (Sweden)

    Gershim Asiki

    Full Text Available The burden of dyslipidaemia is rising in many low income countries. However, there are few data on the prevalence of, or risk factors for, dyslipidaemia in Africa.In 2011, we used the WHO Stepwise approach to collect cardiovascular risk data within a general population cohort in rural south-western Uganda. Dyslipidaemia was defined by high total cholesterol (TC ≥ 5.2 mmol/L or low high density lipoprotein cholesterol (HDL-C 6% (men aOR=3.00, 95%CI=1.37-6.59; women aOR=2.74, 95%CI=1.77-4.27. The odds of high TC was also higher among married men, and women with higher education or high BMI.Low HDL-C prevalence in this relatively young rural population is high whereas high TC prevalence is low. The consequences of dyslipidaemia in African populations remain unclear and prospective follow-up is required.

  16. LIMNOLOGY, LAKE BASINS, LAKE WATERS

    Directory of Open Access Journals (Sweden)

    Petre GÂŞTESCU

    2009-06-01

    Full Text Available Limnology is a border discipline between geography, hydrology and biology, and is also closely connected with other sciences, from it borrows research methods. Physical limnology (the geography of lakes, studies lake biotopes, and biological limnology (the biology of lakes, studies lake biocoenoses. The father of limnology is the Swiss scientist F.A. Forel, the author of a three-volume entitled Le Leman: monographie limnologique (1892-1904, which focuses on the geology physics, chemistry and biology of lakes. He was also author of the first textbook of limnology, Handbuch der Seenkunde: allgemeine Limnologie,(1901. Since both the lake biotope and its biohydrocoenosis make up a single whole, the lake and lakes, respectively, represent the most typical systems in nature. They could be called limnosystems (lacustrine ecosystems, a microcosm in itself, as the American biologist St.A. Forbes put it (1887.

  17. Smoking is the most frequent risk factor for cardiovascular diseases in Croatian Western region: findings of the Croatian health survey 2003

    Directory of Open Access Journals (Sweden)

    Henrietta Benčević-Striehl,

    2009-08-01

    Full Text Available Aim To estimate the prevalence of selected behavioral risk factorsfor cardiovascular diseases in the western region of Croatia and todetermine the differences based on age and gender.Methods A national survey on health status and health behavior ofthe adult population has been conducted. The representative sampleof 10,766 households for six officially defined regions of Croatiahas been determined, and Western region has been included with1,562 inhabitants, aged 18 years and older. The overall responserate of administered face-to-face questionnaire was 85-6%. Prevalencerates per 100 inhabitants (smoking, eating habits, alcoholconsumption, physical activity, socio-economic characteristics,chronic conditions have been determined.Results Nearly half (46.3% of the adults were smokers or hadquit smoking less than 10 years ago. Prevalence of high bloodpressure was high amounting to 40.6% and it was higher in middleaged males (46.7%, p<0.01 and young males (13.7%, p<0.01.Prevalence of obesity was 38.9%, highest in females aged 35-64(51.2%, p<0.001 and 65 and older (73.8%, p<0.01.Almost a quarter of respondents (23.3% has been insufficientlyphysically active, especially young females 22.5%, p<0.01.Conclusion There was a significant difference in the prevalenceof all observed behavioral risk factors according to the gender andage. Moreover, smoking tobacco has been found as the most frequentrisk factor in the observed population.

  18. Digital Surface and Terrain Models (DSM,DTM), Nearshore topographic and bathymetric survey along the Lake Michigan coast immediately north and south of St. Joseph River outlet in the City of St. Joseph, Michigan, Published in 2017, 1:1200 (1in=100ft) scale, Michigan Coastal Zone Management Program.

    Data.gov (United States)

    NSGIC State | GIS Inventory — Digital Surface and Terrain Models (DSM,DTM) dataset current as of 2017. Nearshore topographic and bathymetric survey along the Lake Michigan coast immediately north...

  19. Diversity of bivalve mollusks of the Teletzkoye Lake (Altay Mts.)

    OpenAIRE

    АНДРЕЕВА С.И.; АНДРЕЕВ Н.И.; Винарский, М. В.

    2016-01-01

    Seven species of Bivalvia (finger-clams) have been revealed in the malacofauna of the Teletskoye Lake (Mountain Altay, Western Siberia) on the basis of 2008 year sampling. Their zoogeographical characteristics is given. Taxonomically, the fauna of Bivalvia of the lake can be characterized as rather poor, with absence of several families and genera widely distributed in Western Siberia

  20. Small mammal trapping mark/recapture baseline surveys at Island Arm-Becharof Lake and Mother Goose Lake, Alaska Peninsula/Becharof National Wildlife Refuge Complex, Alaska, June-September 1995

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In conjunction with baseline ecosystem data being gathered on the Becharof Lake drainage, a small mammal trapping project was undertaken at two of three field camps...

  1. Prevalence of lower urinary tract symptoms, overactive bladder and urinary incontinence in western Turkey: results of a population-based survey.

    Science.gov (United States)

    Zumrutbas, Ali E; Bozkurt, Ali I; Tas, Erdogan; Acar, Cenk I; Alkis, Okan; Coban, Kazim; Cetinel, Bulent; Aybek, Zafer

    2014-10-01

    To estimate the prevalence of lower urinary tract symptoms, urinary incontinence and overactive bladder in western Turkey. This cross-sectional, population-based survey was carried out between May and October 2012. A random sample of 2128 women and men aged ≥18 years was selected from the health registries. A questionnaire including sociodemographic data, comorbid conditions, lower urinary tract symptoms, overactive bladder and urinary incontinence symptoms, body mass index, vital signs, and dipstick urinalysis was developed. The questions were answered by the participants, and remaining data were provided by the site staff. International Continence Society definitions were used. A total of 1571 (74%) individuals agreed to participate, and analysis were carried out on 1555 people (636 men [40.9%] and 919 women [59.1%]) after 16 individuals with a nitrite-positive dipstick test were excluded. Lower urinary tract symptoms were reported by 71.0% of the study population. The prevalence of storage, voiding and post-micturition symptoms were 56.1% (44.2% men, 64.1% women), 39.3% (40.9% men, 37.8% women) and 30.7% (38.6% men, 28.7% women), respectively. The most prevalent storage symptom was urgency, which was reported by 29.3% of the study population (20.1% men, 35.6% women). The prevalence of urge, stress and mixed urinary incontinence were: 6.5% (3.9% men, 8.2% women), 14.1% (3.9% men, 21.2% women) and 5.6% (0.8% men, 9.0% women), respectively. The present study is the first and largest population-based survey evaluating the prevalence of lower urinary tract symptoms, urinary incontinence and overactive bladder in Turkey. Our findings show these symptoms are highly prevalent in western Turkey. © 2014 The Japanese Urological Association.

  2. A Survey on the Prevalence and Histopathological Findings of Lernaea spp. in Schizocypris altidorsalis Fish From Chahnimeh Lakes and Hamoun Wetland in Southeast Iran

    Directory of Open Access Journals (Sweden)

    Mohammad RAHNAMA

    2017-01-01

    Full Text Available The aim of the present study was to assess the prevalence and pathology of Lernaeid parasites in Schizocypris altidorsalis (Anjak Fish fish from Chahnimeh lakes and Hamoun wetland in Sistan and Baluchestan, Iran. A total of 1000 S. altidorsalis fish were collected from October 2014 to September 2015. The prevalence of Lernaea spp. infestation in examined fish was found to be 61.1% (611/1000. Among the examined weight groups, the highest infestation rate (61.7% was recorded in the weight group of 80-100g, followed by 60.5% and 58.7% in 100-150g and 150-200g weight groups, respectively (P>0.05. The frequency of Lernaea spp. in winter (75.2% was higher than other seasons and the lowest prevalence was observed in summer (38%. The association between the season and the prevalence of Lernaea spp. infestation was statistically significant (P<0.001. The histopathological examination of the sections revealed lesions and ulcers in the epidermis, dermis, and muscles of the fish. Chronic inflammatory reaction and infiltration of inflammatory cells including lymphocytes, plasma cells, macrophages, and eosinophils around the parasite attachment sites were observed. In severe cases, various degrees of degeneration and necrosis were seen in the muscle. The present survey revealed a high prevalence of Lernaeid parasites in S. altidorsalis fish and necessitates appropriate control programs.

  3. Use of aerial photographs, Landsat TM imagery and multidisciplinary field survey for land-cover change analysis in the lakes region (Ethiopia)

    Science.gov (United States)

    Rembold, Felix; Carnicelli, Stefano; Nori, Michele; Ferrari, Giovanni A.

    Early multidisciplinary surveys in the Lakes region of central/south Ethiopia show a highly variable land cover pattern characterised by complex interactions between environmental parameters and socio-economic dynamics. From an ecological point of view the area is highly sensitive and both food security and soil conservation are becoming serious problems for the rapidly growing population. The intensive land cover changes observed in this area during the last few decades beg accurate analysis. Land-cover change analysis over a long time-span was performed. Interpretation (API) of aerial photographs dated 1972 and classification of a 1994 Landsat TM image were used. Problems due to the heterogeneous nature of the data were overcome with a method for quantifying land cover on aerial photographs, thus producing data comparable to TM classification results. As land cover is linked, through land use, to social dynamics, in ground control use was made of the results of parallel socio-economic investigations. From the analysis, a general trend of increase in cultivated surfaces was noted. Unique strategies of land allocation according to physical settings were observed. A trend in the evolution of badlands was identified: rapid reactivation of previous erosion in newly cropped areas occurred; within a few decades this erosion reached quasi-equilibrium. The methods adopted showed some accuracy limitations, but allowed land-cover change analysis over a 22-year time-span, providing important insight into recent phenomena and present trends.

  4. HIV infection in fishing communities of Lake Victoria Basin of Uganda--a cross-sectional sero-behavioral survey.

    Science.gov (United States)

    Opio, Alex; Muyonga, Michael; Mulumba, Noordin

    2013-01-01

    Uganda's first AIDS case was reported in a fishing village. Thereafter, due to varying risk factors, the epidemic spread heterogeneously to all regions, with some populations more affected. Given the recent rising trends in HIV infection in Uganda, it is crucial to know the risk factors in different populations. The aim of this study was to determine the prevalence and risk factors of HIV infection among fishing communities. A cross-sectional survey of 46 fishing communities was conducted in 2010. Following written consent, 911 randomly selected respondents age 15-59 years were interviewed and gave blood for HIV testing. HIV testing was conducted in the field and central laboratory according to national algorithm. Survey protocol was approved by the Science and Ethics Committee of Uganda Virus Research Institute, and cleared by Uganda National Council for Science and Technology. Data was captured by EPIINFO and statistical analysis done in SPSS. Overall HIV prevalence was 22%; there was no difference by sex (x (2) test, p>0.05). Association with HIV infection was determined by x (2) test, p<0.5. Never married respondents had lower HIV prevalence (6.2%) than the ever married (24.1%). HIV prevalence was lower in younger respondents, age 15-24 years (10.8%) than in age group 25 years and above (26.1%). Muslims had lower HIV prevalence (14.4%) than Christians (25.2%). HIV prevalence was higher among respondents reporting 3 or more lifetime sexual partners (25.3%) than in those reporting less numbers (10.8%). HIV prevalence was higher among uncircumcised men (27%) than in circumcised men (11%). Multivariate analysis identified 4 risk factors for HIV infection; age, religion, ever condom use and number of lifetime sexual partners. HIV prevalence in the surveyed communities was three times higher than of general population. This underscores the need for tailor made HIV combination prevention interventions targeting fishing communities.

  5. HIV infection in fishing communities of Lake Victoria Basin of Uganda--a cross-sectional sero-behavioral survey.

    Directory of Open Access Journals (Sweden)

    Alex Opio

    Full Text Available BACKGROUND: Uganda's first AIDS case was reported in a fishing village. Thereafter, due to varying risk factors, the epidemic spread heterogeneously to all regions, with some populations more affected. Given the recent rising trends in HIV infection in Uganda, it is crucial to know the risk factors in different populations. The aim of this study was to determine the prevalence and risk factors of HIV infection among fishing communities. METHODOLOGY: A cross-sectional survey of 46 fishing communities was conducted in 2010. Following written consent, 911 randomly selected respondents age 15-59 years were interviewed and gave blood for HIV testing. HIV testing was conducted in the field and central laboratory according to national algorithm. Survey protocol was approved by the Science and Ethics Committee of Uganda Virus Research Institute, and cleared by Uganda National Council for Science and Technology. Data was captured by EPIINFO and statistical analysis done in SPSS. FINDINGS: Overall HIV prevalence was 22%; there was no difference by sex (x (2 test, p>0.05. Association with HIV infection was determined by x (2 test, p<0.5. Never married respondents had lower HIV prevalence (6.2% than the ever married (24.1%. HIV prevalence was lower in younger respondents, age 15-24 years (10.8% than in age group 25 years and above (26.1%. Muslims had lower HIV prevalence (14.4% than Christians (25.2%. HIV prevalence was higher among respondents reporting 3 or more lifetime sexual partners (25.3% than in those reporting less numbers (10.8%. HIV prevalence was higher among uncircumcised men (27% than in circumcised men (11%. Multivariate analysis identified 4 risk factors for HIV infection; age, religion, ever condom use and number of lifetime sexual partners. CONCLUSIONS: HIV prevalence in the surveyed communities was three times higher than of general population. This underscores the need for tailor made HIV combination prevention interventions targeting

  6. HIV Infection in Fishing Communities of Lake Victoria Basin of Uganda – A Cross-Sectional Sero-Behavioral Survey

    Science.gov (United States)

    Opio, Alex; Muyonga, Michael; Mulumba, Noordin

    2013-01-01

    Background Uganda's first AIDS case was reported in a fishing village. Thereafter, due to varying risk factors, the epidemic spread heterogeneously to all regions, with some populations more affected. Given the recent rising trends in HIV infection in Uganda, it is crucial to know the risk factors in different populations. The aim of this study was to determine the prevalence and risk factors of HIV infection among fishing communities. Methodology A cross-sectional survey of 46 fishing communities was conducted in 2010. Following written consent, 911 randomly selected respondents age 15–59 years were interviewed and gave blood for HIV testing. HIV testing was conducted in the field and central laboratory according to national algorithm. Survey protocol was approved by the Science and Ethics Committee of Uganda Virus Research Institute, and cleared by Uganda National Council for Science and Technology. Data was captured by EPIINFO and statistical analysis done in SPSS. Findings Overall HIV prevalence was 22%; there was no difference by sex (x2 test, p>0.05). Association with HIV infection was determined by x2 test, p<0.5. Never married respondents had lower HIV prevalence (6.2%) than the ever married (24.1%). HIV prevalence was lower in younger respondents, age 15–24 years (10.8%) than in age group 25 years and above (26.1%). Muslims had lower HIV prevalence (14.4%) than Christians (25.2%). HIV prevalence was higher among respondents reporting 3 or more lifetime sexual partners (25.3%) than in those reporting less numbers (10.8%). HIV prevalence was higher among uncircumcised men (27%) than in circumcised men (11%). Multivariate analysis identified 4 risk factors for HIV infection; age, religion, ever condom use and number of lifetime sexual partners. Conclusions HIV prevalence in the surveyed communities was three times higher than of general population. This underscores the need for tailor made HIV combination prevention interventions targeting fishing

  7. Beta-haemolytic group A, C and G streptococcal infections in Western Norway: a 15-year retrospective survey.

    Science.gov (United States)

    Oppegaard, O; Mylvaganam, H; Kittang, B R

    2015-02-01

    Pyogenic streptococci cause significant morbidity and mortality, and the incidence of invasive group C and G streptococcal disease appears to be increasing. In this retrospective study we describe the epidemiological characteristics of invasive group A, C and G, along with non-invasive group C and G streptococcal infections in Western Norway from 1999 to 2013. A total of 512 invasive streptococcal infections were identified, of these 297 (58%) were group A (GAS), 24 (5%) group C (GCS) and 188 (37%) group G streptococci (GGS). In the non-invasive group, 4935 GCS and GGS-infections were identified. GCS and GGS were treated as one group (GCGS) for statistical purposes. All microbial categories displayed increasing incidence with age, seasonal variation and a male predominance. The incidence of invasive GCGS infections increased significantly from 1.4/100,000 inhabitants in 1999 to 6.3/100,000 in 2013 (p streptococcal disease in our community calls for sustained attentiveness to the clinical and molecular aspects of GAS, GCS and GGS infections. Copyright © 2014 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  8. Questionnaire-based survey on the distribution and incidence of canine babesiosis in countries of Western Europe

    Directory of Open Access Journals (Sweden)

    Halos Lénaïg

    2014-01-01

    Full Text Available The incidence of canine babesiosis may vary considerably from one country to another depending on the distribution of the causative parasite species and their specific vectors. The aim of the present study was to evaluate the clinical occurrence of canine babesiosis diagnosed in European veterinary clinics and propose an updated map of the disease distribution in Western Europe. Questionnaires were sent to companion animal veterinary clinics in Spain, France, Benelux, Germany and Austria. The annual number of babesiosis cases in 2010, the number of practitioners in the clinic and the location of the clinic were recorded. The total numbers of dogs and practitioners in each country were used for definition of the reference populations and the annual incidence of canine babesiosis was calculated by dividing the total number of reported babesiosis cases by the total number of dogs in the veterinary practices involved in the study. Data were georeferenced for distribution map construction. The overall annual incidence of clinical babesiosis amongst the investigated dog population was 0.7%, with significant variations amongst countries and regions. Three epidemiological situations were described: (i Spain, with co-existence of several species of piroplasms and patchy distribution of babesiosis, (ii France, with overall presence of babesiosis due to Babesia canis and local variations and (iii Benelux, Germany and Austria, with overall low prevalence of the disease associated with localised description related either to imported cases or to small autochthonous foci of B. canis infection.

  9. A millennial-long record of warm season precipitation and flood frequency for the North-western Alps inferred from varved lake sediments: implications for the future

    Science.gov (United States)

    Amann, Benjamin; Szidat, Sönke; Grosjean, Martin

    2015-05-01

    The recent warming of the global climate is well recognized. However, does a warmer climate also mean a moister climate? Does dry get drier and wet get wetter? There are important questions as they relate to changes in the water cycle and impacts the water resources as well as the frequency and intensity of storms and floods in the near future. In Europe, regional climate models do not show consistent and robust results for future hydroclimatic changes and how extreme events will evolve in response to future climate change. Paleo-hydroclimatic data from natural archives are one of the few means to assess such changes in the longer context. Here, we present an annually-resolved record of warm season (MJJA) precipitation and summer flood frequency from the varved (annually laminated) sediments of proglacial Lake Oeschinen (46°30‧N-7°44‧E, 1580 m, NW Swiss Alps) back to AD 884. These data sets are inferred from the thickness of annual sediment deposits and the occurrence of flood event layers in the sediments. The chronology of the sediment record is based on multiple varve counts and validated with historical floods chronicled in written documents (back to the 14th century) and 14C AMS dates. The precipitation record shows pronounced interannual to centennial variability with humid warm season phases between AD 920-950, AD 1100-1180, AD 1300-1400, AD 1590-1650, AD 1700-1790, AD 1820-1880, and AD 1960-2008. Driest conditions are reconstructed for AD 960-1080, AD 1250-1300 and for AD 1880-1900. Our precipitation record is consistent with the few multi-centennial warm-season precipitation records available for Europe. We did not find a persistent relationship between warm-season precipitation and temperature. In contrast, results show that the relation between precipitation and temperature has oscillated between positive correlations (warmer gets wetter, cooler gets drier) and negative correlations (warmer gets drier, cooler gets wetter) with a highly significant

  10. Prevalence and Fertility Survey of Hydatid Cyst in Slaughtered Livestock in Hamadan Abattoir, Western Iran, 2015 - 2016

    Directory of Open Access Journals (Sweden)

    Malihe Roostaei

    2017-04-01

    Full Text Available Background Cystic echinococcosis (CE is a cosmopolitan zoonotic infection which is considered as a significant public health and economic concern. Livestock is the main intermediate host for Echinococcus granulosus. Objectives This study was conducted to evaluate the prevalence and fertility rate of hydatid cyst among livestock in Hamadan area, western Iran. Methods A total of 10626 livestock carcasses were examined through visual inspection in order to detect hydatid cyst in Hamadan industrial slaughterhouse, during 2015 - 2016. The viability and fertility of hydatid cyst were determined microscopically by flame cell activity and eosin dye uptake. Results The carcasses, including 8684 sheep, 1110 goats and 832 cattle were inspected in order to detect hydatid cyst. An overall CE was detected in 3% of the inspected carcasses with a prevalence rate of 5.3% in cattle, 3% in sheep and 1% in goats (P < 0.001. The prevalence rate of infection in the females (2.7% was more than males (0.3% (P < 0.001. All of the infected animals were aged one year or more. The highest rate of infection in internal organs was found in the lungs (47.2%. The highest and the lowest fertility rate of hydatid cyst were observed in sheep (69.3% and cattle (6.8%, respectively. The most of hydatid cysts which obtained from cattle (79.6% were suppurative or calcified. Conclusions This study shows that the prevalence rate of CE is considerable in the area and sheep appear to be the most important intermediate hosts for E. granulosus tapeworm.

  11. Aeromagnetic Survey by Small Unmanned Aerial Vehicle with Magneto-Resistant Magnetometer at the northern Kalgoorlie area, Western Australia

    Science.gov (United States)

    Funaki, M.; Group, A.; Milligan, P.

    2006-12-01

    We have developed the technology of small drones (unmanned aerial vehicles (UAV)) and an onboard magnetometer focussed on the aeromagnetic surveys under the Ant-Plane project. We succeeded long distant flight to 500km with agnetometer by Ant-Plene4 drone collaborated with Geoscience, Australia, in March 2006. The survey was carried out in the area 10kmx10km around Mt. Vetters Station, Kalgoorlie, West Australian. The magnetic data are obtained from 41 courses (250m in interval) of EW dierction. The altitude of the flight was 900m from sea level and 500m from the runway. The Ant-Plane #4 consists of 2.6m span and 2.0m length with 2-cycles and 2-cylinder 85cc gasoline engine, GPS navigation system by microcomputer and radio telemeter system. The total weight is 25kg including 12.4 litter fuels and the coursing speed is 130. The magnetometer system consists of a 3-component magneto- resistant magnetometer (MR) sensor (Honeywell HMR2300), GPS and data logger. Three components of magnetic field, latitude, longitude, altitude, the number of satellite and time can be recorded in every second during 6 hours. The sensitivity of the magnetometer is 7 nT and we use a total magnetic field intensity for magnetic analysis due to unknown direction of heading of the plane. MR-magnetometer sensor was installed at the tip of a FRP pipe of 1m length, and the pipe was fixed to the head of the plane in order to reduce the plane magnetization. After 4 hours 14 minutes from the takeoff, the 500km flight was accomplished and the magnetic data were obtained from the data logger. The straight flight course was almost consistent with the way point course, but the course was drastically disturbed when the plane was turning. The magnetic noise level during the flight increased to 30nT, when the plane was flight in the tail wind. However, it is much higher when the plane flew in the head wind. The anomaly pattern obtained from Ant-Plane 4 was compared with the magnetic anomaly map published by

  12. Climate Change and Western Public Lands: a Survey of U.S. Federal Land Managers on the Status of Adaptation Efforts

    Directory of Open Access Journals (Sweden)

    Kelli M. Archie

    2012-12-01

    Full Text Available Climate change and its associated consequences pose an increasing risk to public lands in the western United States. High-level mandates currently require federal agencies to begin planning for adaptation, but the extent to which these mandates have resulted in policies being implemented that affect on the ground practices is unclear. To examine the status of adaptation efforts, we conducted an original survey and semistructured interviews with land managers from the four major federal land management agencies in the U.S. states of Colorado, Utah, and Wyoming. The survey was designed to examine current planning for adaptation on public lands and how it differs from prior planning, the major challenges facing land managers in this region, the major barriers preventing managers from planning for adaptation, and the major hurdles associated with implementing adaptation plans. Our results show that some adaptation planning is currently taking place, but that few adaptation projects have made it to the implementation phase. Overall, respondents considered lack of information at relevant scales, budget constraints, lack of specific agency direction, and lack of useful information to be the most common barriers to adaption planning. Budget constraints, lack of perceived importance to the public, and lack of public awareness or demand to take action were reported to be the biggest hurdles to implementation of adaptation projects. Agencies showed differing levels of adaptation activity, and reported different barriers to adaptation and hurdles to implementation. Reasons for the differences and implications for future research and policy are discussed.

  13. Relationship between socioeconomic status and HIV infection: findings from a survey in the Free State and Western Cape Provinces of South Africa.

    Science.gov (United States)

    Bunyasi, Erick Wekesa; Coetzee, David John

    2017-11-20

    Studies have shown a mixed association between socioeconomic status (SES) and prevalent HIV infection across and within settings in sub-Saharan Africa. In general, the relationship between years of formal education and HIV infection changed from a positive to a negative association with maturity of the HIV epidemic. Our objective was to determine the association between SES and HIV in women of reproductive age in the Free State (FSP) and Western Cape Provinces (WCP) of South Africa (SA). Cross-sectional. SA. We conducted secondary analysis on 1906 women of reproductive age from a 2007 to 2008 survey that evaluated effectiveness of Prevention of Mother-to-Child HIV Transmission Programmes. SES was measured by household wealth quintiles, years of formal education and employment status. Our analysis principally used logistic regression for survey data. There was a significant negative trend between prevalent HIV infection and wealth quintile in WCP (Pstated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  14. Quantification of the CO2 emitted from volcanic lakes in Pico Island (Azores)

    Science.gov (United States)

    Andrade, César; Cruz, José; Viveiros, Fátima; Branco, Rafael

    2017-04-01

    This study shows the results of the diffuse CO2 degassing surveys performed in lakes from Pico volcanic Island (Azores archipelago, Portugal). Detailed flux measurements using the accumulation chamber method were made at six lakes (Capitão, Caiado, Paul, Rosada, Peixinho and Negra) during two field campaigns, respectively, in winter (February 2016) and late summer (September 2016). Pico is the second largest island of the Azores archipelago with an area of 444.8 km2; the oldest volcanic unit is dated from about 300,000 years ago. The edification of Pico was mainly due to Hawaiian and Strombolian type volcanic activity, resulting in pahoehoe and aa lava flows of basaltic nature, as well as scoria and spatter cones. Three main volcanic complexes are identified in the island, namely (1) the so-called Montanha Volcanic Complex, corresponding to a central volcano located in the western side of the island that reaches a maximum altitude of 2351 m, (2) the São Roque-Piedade Volcanic Complex, and (3) the Topo-Lajes Volcanic Complex, this last one corresponding to the remnants of a shield volcano located in the south coast. The studied lakes are spread along the São Roque-Piedade Volcanic Complex at altitudes between 785 m and 898 m. Three are associated with depressions of undifferentiated origin (Caiado, Peixinho, Negra), two with depressions of tectonic origin (Capitão, Paul), while Rosada lake is located inside a scoria cone crater. The lakes surface areas vary between 1.25x10-2 and 5.38x10-2 km2, and the water column maximum depth is 7.9 m (3.5-7.9 m). The water storage ranges between 3.6x104 to 9.1x104 m3, and the estimated residence time does not exceed 1.8x10-1 years. A total of 1579 CO2 flux measurements were made during both surveys (868 in summer and 711 in the winter campaign), namely 518 in Caiado lake (293; 225), 358 in Paul (195; 163), 279 in Capitão (150, 129), 200 in Rosada (106, 94), 171 in Peixinho (71, 100) and 53 measurements in Negra lake. Negra

  15. Sexual and reproductive health trends among women with enduring mental illness: a survey of Western Australian community mental health services.

    Science.gov (United States)

    Hauck, Yvonne; Nguyen, Thinh; Frayne, Jacqueline; Garefalakis, Maria; Rock, Daniel

    2015-01-01

    An exploratory cross-sectional survey was conducted to determine associations and potential modifiable risk factors for management of sexual and reproductive health needs for women attending community mental health services. Women (n = 220) had on average three pregnancies; 61.2% were unplanned. One quarter who were sexually active within the past 12 months denied using contraception with 51% using less effective methods. The majority (81.7%) engaged in Pap smear screening, and those with a general practitioner (GP) were more likely to participate (p =.004). Findings highlight GPs' potential in optimizing women's health. Considering unplanned pregnancies and contraception trends, we suggest improved access to contraception options, particularly long-acting reversible methods.

  16. Analysis of elevation changes detected from multi-temporal LiDAR surveys in forested landslide terrain in western Oregon

    Science.gov (United States)

    Burns, W.J.; Coe, J.A.; Kaya, B.S.; Ma, Liwang

    2010-01-01

    We examined elevation changes detected from two successive sets of Light Detection and Ranging (LiDAR) data in the northern Coast Range of Oregon. The first set of LiDAR data was acquired during leafon conditions and the second set during leaf-off conditions. We were able to successfully identify and map active landslides using a differential digital elevation model (DEM) created from the two LiDAR data sets, but this required the use of thresholds (0.50 and 0.75 m) to remove noise from the differential elevation data, visual pattern recognition of landslideinduced elevation changes, and supplemental QuickBird satellite imagery. After mapping, we field-verified 88 percent of the landslides that we had mapped with high confidence, but we could not detect active landslides with elevation changes of less than 0.50 m. Volumetric calculations showed that a total of about 18,100 m3 of material was missing from landslide areas, probably as a result of systematic negative elevation errors in the differential DEM and as a result of removal of material by erosion and transport. We also examined the accuracies of 285 leaf-off LiDAR elevations at four landslide sites using Global Positioning System and total station surveys. A comparison of LiDAR and survey data indicated an overall root mean square error of 0.50 m, a maximum error of 2.21 m, and a systematic error of 0.09 m. LiDAR ground-point densities were lowest in areas with young conifer forests and deciduous vegetation, which resulted in extensive interpolations of elevations in the leaf-on, bare-earth DEM. For optimal use of multi-temporal LiDAR data in forested areas, we recommend that all data sets be flown during leaf-off seasons.

  17. Ethnobotanical survey of medicinal plants commonly used by Kani tribals in Tirunelveli hills of Western Ghats, India.

    Science.gov (United States)

    Ayyanar, Muniappan; Ignacimuthu, Savarimuthu

    2011-04-12

    For thousands of years, medicinal plants have played an important role throughout the world in treating and preventing a variety of diseases. Kani tribal people in Tirunelveli hills still depend on medicinal plants and most of them have a general knowledge of medicinal plants which are used for first aid remedies, to treat cough, cold, fever, headache, poisonous bites and some simple ailments. The present study was initiated with an aim to identify traditional healers who are practicing herbal medicine among the Kani tribals in Tirunelveli hills of Western Ghats, India and quantitatively document their indigenous knowledge on the utilization of medicinal plants particularly most common ethnomedicinal plants. Field study was carried out over a period of 4 years in Tirunelveli hills. The ethnomedicinal information was collected through interviews among the Kani traditional healers. The collected data were analyzed through use value (UV), informant consensus factor (F(ic)), fidelity level (FL) and relative importance (RI). A total of 90 species of plants distributed in 83 genera belonging to 52 families were identified as commonly used ethnomedicinal plants by the Kani traditional healers in Tirunelveli hills for the treatment of 65 types of ailments. These ailments were categorized into 15 ailment categories based on the body systems treated. Leaves were the most frequently used plant parts and most of the medicines were prepared in the form of paste and administered orally. F(ic) values of the present study indicated that there was a high agreement in the use of plants in the treatment of jaundice and diabetes among the users. Dermatological infections/diseases and gastro-intestinal disorders had highest use-reports and 29 species of plants had the highest fidelity level of 100%. The most important species according to their use value were Gymneme sylvestre (2.00), Melia azedarach, Murraya koenigii, Syzygium cumini and Terminalia chebula (1.83). As a result of the

  18. Investigation of Relationship Between Hydrologic Processes of Precipitation, Evaporation and Stream Flow Using Linear Time Series Models (Case study: Western Basins of Lake Urmia

    Directory of Open Access Journals (Sweden)

    M. Moravej

    2016-02-01

    Full Text Available Introduction: Studying the hydrological cycle, especially in large scales such as water catchments, is difficult and complicated despite the fact that the numbers of hydrological components are limited. This complexity rises from complex interactions between hydrological components and environment. Recognition, determination and modeling of all interactive processes are needed to address this issue, but it's not feasible for dealing with practical engineering problems. So, it is more convenient to consider hydrological components as stochastic phenomenon, and use stochastic models for modeling them. Stochastic simulation of time series models related to water resources, particularly hydrologic time series, have been widely used in recent decades in order to solve issues pertaining planning and management of water resource systems. In this study time series models fitted to the precipitation, evaporation and stream flow series separately and the relationships between stream flow and precipitation processes are investigated. In fact, the three mentioned processes should be modeled in parallel to each other in order to acquire a comprehensive vision of hydrological conditions in the region. Moreover, the relationship between the hydrologic processes has been mostly studied with respect to their trends. It is desirable to investigate the relationship between trends of hydrological processes and climate change, while the relationship of the models has not been taken into consideration. The main objective of this study is to investigate the relationship between hydrological processes and their effects on each other and the selected models. Material and Method: In the current study, the four sub-basins of Lake Urmia Basin namely Zolachay (A, Nazloochay (B, Shahrchay (C and Barandoozchay (D were considered. Precipitation, evaporation and stream flow time series were modeled by linear time series. Fundamental assumptions of time series analysis namely

  19. History of malaria treatment as a predictor of subsequent subclinical parasitaemia: a cross-sectional survey and malaria case records from three villages in Pailin, western Cambodia.

    Science.gov (United States)

    Peto, Thomas J; Kloprogge, Sabine E; Tripura, Rupam; Nguon, Chea; Sanann, Nou; Yok, Sovann; Heng, Chhouen; Promnarate, Cholrawee; Chalk, Jeremy; Song, Ngak; Lee, Sue J; Lubell, Yoel; Dhorda, Mehul; Imwong, Mallika; White, Nicholas J; von Seidlein, Lorenz; Dondorp, Arjen

    2016-04-26

    Treatment of the sub-clinical reservoir of malaria, which may maintain transmission, could be an important component of elimination strategies. The reliable detection of asymptomatic infections with low levels of parasitaemia requires high-volume quantitative polymerase chain reaction (uPCR), which is impractical to conduct on a large scale. It is unknown to what extent sub-clinical parasitaemias originate from recent or older clinical episodes. This study explored the association between clinical history of malaria and subsequent sub-clinical parasitaemia. In June 2013 a cross-sectional survey was conducted in three villages in Pailin, western Cambodia. Demographic and epidemiological data and blood samples were collected. Blood was tested for malaria by high-volume qPCR. Positive samples were analysed by nested PCR to determine the Plasmodium species. To identify previous episodes of malaria, case records were collected from village malaria workers and local health facilities and linked to study participants. Among 1343 participants, 40/122 (32.8 %) with a history of clinical malaria were parasitaemic during the cross-sectional survey, compared to 172/1221 (14.1 %) without this history (p history of clinical malaria, compared to 87 out of 1131 (7.7 %) parasite-negative participants; p history of Plasmodium vivax was associated with sub-clinical P. vivax parasitaemia in the survey (p history of P. falciparum. A clinical episode of vivax malaria was associated with subsequent sub-clinical parasitaemia. Treatment of P. vivax with artemisinin-based combination therapy without primaquine often resulted in recurrent episodes. Targeting individuals with a history of clinical malaria will be insufficient to eliminate the sub-clinical reservoir as they constitute a minority of parasitaemias.

  20. Association of common mental disorder symptoms with health and healthcare factors among women in rural western India: results of a cross-sectional survey.

    Science.gov (United States)

    Soni, Apurv; Fahey, Nisha; Byatt, Nancy; Prabhakaran, Anusha; Moore Simas, Tiffany A; Vankar, Jagdish; Phatak, Ajay; O'Keefe, Eileen; Allison, Jeroan; Nimbalkar, Somashekhar

    2016-07-07

    Information about common mental disorders (CMD) is needed to guide policy and clinical interventions in low-income and middle-income countries. This study's purpose was to characterise the association of CMD symptoms with 3 inter-related health and healthcare factors among women from rural western India based on a representative, cross-sectional survey. Surveys were conducted in the waiting area of various outpatient clinics at a tertiary care hospital and in 16 rural villages in the Anand district of Gujarat, India. 700 Gujarati-speaking women between the ages of 18-45 years who resided in the Anand district of Gujarat, India, were recruited in a quasi-randomised manner. CMD symptoms, ascertained using WHO's Self-Reporting Questionnaire-20 (SRQ-20), were associated with self-reported (1) number of healthcare visits in the prior year; (2) health status and (3) portion of yearly income expended on healthcare. Data from 658 participants were used in this analysis; 19 surveys were excluded due to incompleteness, 18 surveys were excluded because the participants were visiting hospitalised patients and 5 surveys were classified as outliers. Overall, 155 (22·8%) participants screened positive for CMD symptoms (SRQ-20 score ≥8) with most (81.9%) not previously diagnosed despite contact with healthcare provider in the prior year. On adjusted analyses, screening positive for CMD symptoms was associated with worse category in self-reported health status (cumulative OR=9.39; 95% CI 5·97 to 14·76), higher portion of household income expended on healthcare (cumulative OR=2·31; 95% CL 1·52 to 3.52) and increased healthcare visits in the prior year (incidence rate ratio=1·24; 95% CI 1·07 to 1·44). The high prevalence of potential CMD among women in rural India that is unrecognised and associated with adverse health and financial indicators highlights the individual and public health burden of CMD. Published by the BMJ Publishing Group Limited. For permission to use

  1. Great Lakes Research Vessel Operations 1958-2016

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Great Lakes Research Vessel Operations data release is taken from the Research Vessel Catch (RVCAT) database curated at the Great Lakes Science Center (GLSC)....

  2. Determinants and Coverage of Vaccination in Children in Western Kenya from a 2003 Cross-Sectional Survey

    Science.gov (United States)

    Calhoun, Lisa M.; van Eijk, Anna M.; Lindblade, Kim A.; Odhiambo, Frank O.; Wilson, Mark L.; Winterbauer, Elizabeth; Slutsker, Laurence; Hamel, Mary J.

    2014-01-01

    This study assesses full and timely vaccination coverage and factors associated with full vaccination in children ages 12–23 months in Gem, Nyanza Province, Kenya in 2003. A simple random sample of 1,769 households was selected, and guardians were invited to bring children under 5 years of age to participate in a survey. Full vaccination coverage was 31.1% among 244 children. Only 2.2% received all vaccinations in the target month for each vaccination. In multivariate logistic regression, children of mothers of higher parity (odds ratio [OR] = 0.27, 95% confidence interval [95% CI] = 0.13–0.65, P ≤ 0.01), children of mothers with lower maternal education (OR = 0.35, 95% CI = 0.13–0.97, P ≤ 0.05), or children in households with the spouse absent versus present (OR = 0.40, 95% CI = 0.17–0.91, P ≤ 0.05) were less likely to be fully vaccinated. These data serve as a baseline from which changes in vaccination coverage will be measured as interventions to improve vaccination timeliness are introduced. PMID:24343886

  3. SEROLOGICAL SURVEY OF TOXOPLASMOSIS, NEOSPOROSIS AND BRUCELLOSIS AMONG CATTLE HERDS IN OYO STATE, SOUTH-WESTERN NIGERIA.

    Science.gov (United States)

    Ayinmode, Adekunle; Akinseye, Victor; Schares, Gereon; Cadmus, Simeon

    2017-01-01

    Several zoonotic diseases are known to constitute great impediment to livestock management and production worldwide, especially in developing countries where control measures are largely non-existent. This study sets out to investigate the occurrence of toxoplasmosis, neosporosis and brucellosis among cattle herds in Oyo State, southwest Nigeria. A cross-sectional survey to screen for antibodies to Toxoplasma gondii , Neospora caninum and Brucella abortus was conducted among 174 cattle in 17 herds. Sera obtained from the cattle were screened for antibodies to Toxoplasma gondii and Neospora caninum using enzyme-linked immunosorbent assay (ELISA) and for Brucella abortus antibodies using Rose Bengal test and Competitive Enzyme Linked Immunosorbent Assay (cELISA). Overall, herd level prevalence of 52.9%, 23.5% and 23.5% as well as individual prevalence of 7.5%, 3.4% and 3.4% was obtained for toxoplasmosis, neosporosis and brucellosis, respectively. Antibodies to T. gondii , N. caninum and B. abortus were detected in 2 of the 17 herds, T. gondii and N. caninum in 4 herds, and T. gondii and B. abortus in 4 herds. Statistically significant association was only found between seropositivity to T. gondii antibodies and sex (pneosporosis and brucellosis are prevalent among cattle herds screened in the study area. Considering the potential impact of these diseases on livestock management and production, extensive surveillance is necessary for development and implementation of effective control and prevention strategies.

  4. Ectoparasitism on deep-sea fishes in the western North Atlantic: In situ observations from ROV surveys

    Directory of Open Access Journals (Sweden)

    Andrea M. Quattrini

    2016-12-01

    Full Text Available A complete understanding of how parasites influence marine ecosystem functioning requires characterizing a broad range of parasite-host interactions while determining the effects of parasitism in a variety of habitats. In deep-sea fishes, the prevalence of parasitism remains poorly understood. Knowledge of ectoparasitism, in particular, is limited because collection methods often cause dislodgment of ectoparasites from their hosts. High-definition video collected during 43 remotely operated vehicle surveys (2013–2014 provided the opportunity to examine ectoparasitism on fishes across habitats (open slope, canyon, seamount, cold seep and depths (494–4689 m off the northeastern U.S., while providing high-resolution images and valuable observations of fish behavior. Only 9% (n = 125 individuals of all observed fishes (25 species were confirmed with ectoparasites, but higher percentages (∼33% were observed for some of the most abundant fish species (e.g., Antimora rostrata. Ectoparasites included two copepod families (Lernaeopodidae, Sphyriidae that infected four host species, two isopod families (Cymothoidae, Aegidae that infected three host species, and one isopod family (Gnathiidae that infected 19 host species. Hyperparasitism was also observed. As host diversity declined with depth, ectoparasite diversity declined; only gnathiids were observed at depths down to 3260 m. Thus, gnathiids appear to be the most successful group to infect a diversity of fishes across a broad depth range in the deep sea. For three dominant fishes (A. rostrata, Nezumia bairdii, Synaphobranchus spp., the abundance and intensity of ectoparasitism peaked in different depths and habitats depending on the host species examined. Notably, gnathiid infections were most intense on A. rostrata, particularly in submarine canyons, suggesting that these habitats may increase ectoparasite infections. Although ectoparasitism is often overlooked in deep-sea benthic

  5. Ectoparasitism on deep-sea fishes in the western North Atlantic: In situ observations from ROV surveys

    Science.gov (United States)

    Quattrini, Andrea; Demopoulos, Amanda W.J.

    2016-01-01

    A complete understanding of how parasites influence marine ecosystem functioning requires characterizing a broad range of parasite-host interactions while determining the effects of parasitism in a variety of habitats. In deep-sea fishes, the prevalence of parasitism remains poorly understood. Knowledge of ectoparasitism, in particular, is limited because collection methods often cause dislodgment of ectoparasites from their hosts. High-definition video collected during 43 remotely operated vehicle surveys (2013–2014) provided the opportunity to examine ectoparasitism on fishes across habitats (open slope, canyon, seamount, cold seep) and depths (494–4689 m) off the northeastern U.S., while providing high-resolution images and valuable observations of fish behavior. Only 9% (n = 125 individuals) of all observed fishes (25 species) were confirmed with ectoparasites, but higher percentages (∼33%) were observed for some of the most abundant fish species (e.g., Antimora rostrata). Ectoparasites included two copepod families (Lernaeopodidae, Sphyriidae) that infected four host species, two isopod families (Cymothoidae, Aegidae) that infected three host species, and one isopod family (Gnathiidae) that infected 19 host species. Hyperparasitism was also observed. As host diversity declined with depth, ectoparasite diversity declined; only gnathiids were observed at depths down to 3260 m. Thus, gnathiids appear to be the most successful group to infect a diversity of fishes across a broad depth range in the deep sea. For three dominant fishes (A. rostrata, Nezumia bairdii, Synaphobranchus spp.), the abundance and intensity of ectoparasitism peaked in different depths and habitats depending on the host species examined. Notably, gnathiid infections were most intense on A. rostrata, particularly in submarine canyons, suggesting that these habitats may increase ectoparasite infections. Although ectoparasitism is often overlooked in deep-sea benthic communities

  6. Ectoparasitism on deep-sea fishes in the western North Atlantic: In situ observations from ROV surveys.

    Science.gov (United States)

    Quattrini, Andrea M; Demopoulos, Amanda W J

    2016-12-01

    A complete understanding of how parasites influence marine ecosystem functioning requires characterizing a broad range of parasite-host interactions while determining the effects of parasitism in a variety of habitats. In deep-sea fishes, the prevalence of parasitism remains poorly understood. Knowledge of ectoparasitism, in particular, is limited because collection methods often cause dislodgment of ectoparasites from their hosts. High-definition video collected during 43 remotely operated vehicle surveys (2013-2014) provided the opportunity to examine ectoparasitism on fishes across habitats (open slope, canyon, seamount, cold seep) and depths (494-4689 m) off the northeastern U.S., while providing high-resolution images and valuable observations of fish behavior. Only 9% (n = 125 individuals) of all observed fishes (25 species) were confirmed with ectoparasites, but higher percentages (∼33%) were observed for some of the most abundant fish species (e.g., Antimora rostrata). Ectoparasites included two copepod families (Lernaeopodidae, Sphyriidae) that infected four host species, two isopod families (Cymothoidae, Aegidae) that infected three host species, and one isopod family (Gnathiidae) that infected 19 host species. Hyperparasitism was also observed. As host diversity declined with depth, ectoparasite diversity declined; only gnathiids were observed at depths down to 3260 m. Thus, gnathiids appear to be the most successful group to infect a diversity of fishes across a broad depth range in the deep sea. For three dominant fishes (A. rostrata, Nezumia bairdii, Synaphobranchus spp.), the abundance and intensity of ectoparasitism peaked in different depths and habitats depending on the host species examined. Notably, gnathiid infections were most intense on A. rostrata, particularly in submarine canyons, suggesting that these habitats may increase ectoparasite infections. Although ectoparasitism is often overlooked in deep-sea benthic communities, our

  7. Management strategies for sustainable western water

    Science.gov (United States)

    Scott Tyler; Sudeep Chandra; Gordon Grant

    2017-01-01

    With the effects of the dramatic western US drought still reverberating through the landscape, researchers gathered in advance of the 20th annual Lake Tahoe Summit to discuss western US water issues in the 21st century. This two-day workshop brought together ~40 researchers from universities and agencies (federal and state) to discuss the prospects that...

  8. Crater Lake revealed

    Science.gov (United States)

    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.

  9. Small mammal trapping mark/recapture baseline surveys at Ruth River-Becharof Lake, Alaska Peninsula/Becharof National Wildlife Refuge Complex, Alaska, June-July 1996

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In conjunction with baseline ecosystem data being gathered on the Becharof Lake drainage, a small mammal trapping project was undertaken at 1 of 2 field camps set up...

  10. Small mammal trapping mark/recapture baseline surveys at Gas Rocks-Becharof Lake, Alaska Peninsula/Becharof National Wildlife Refuge Complex, Alaska, June-July 1997

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In conjunction with baseline ecosystem data being gathered on the Becharof Lake drainage, a small mammal trapping project was undertaken at 1 of 2 field camps set up...

  11. Small mammal trapping mark/recapture baseline surveys at Mother Goose Lake, Alaska Peninsula National Wildlife Refuge, Alaska, June-August 1997

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A small mammal trapping project was continued for the third year at Mother Goose Lake on the Alaska Peninsula National Wildlife Refuge. A 100 trap grid was set up in...

  12. Hydrography - HYDROGRAPHY_HIGHRES_WATERBODYDISCRETE_NHD_USGS: Lakes, Ponds, Reservoirs, Swamps, and Marshes in Watersheds of Indiana (U. S. Geological Survey, 1:24,000, Polygon Shapefile)

    Data.gov (United States)

    NSGIC State | GIS Inventory — HYDROGRAPHY_HIGHRES_WATERBODYDISCRETE_NHD_USGS.SHP is a polygon shapefile that contains features of lakes, ponds, reservoirs, swamps and marshes in watersheds in and...

  13. Reactions of nepali adults to warning labels on cigarette packages: a survey with employee and medical students of a tertiary care medical college of Western region of Nepal.

    Science.gov (United States)

    Paudel, Badri; Paudel, Klara; Timilsina, Deepa

    2013-10-01

    For the past 30 years, there have been no changes in the text-only cigarette warning labels in Nepal. During this same time period, other countries placed large graphic warning labels on cigarette packages. The purpose of the current study was primarily to compare the differences in reactions to different types of warning labels on cigarette packages, with a specific focus on whether the new warning label adopted by WHO FCTC was better than the text only label used by Nepal. This study was conducted in Gandaki Medical College Teaching Hospital (GMCTH) in 2012, in a tertiary care hospital located in the western region of Nepal. Eligible study participants included in this survey were those aged 18 years and over and those who are studying MBBS/Nursing or who were employees of GMCTH. 500 participants finished the survey. Participants were shown nine types of warning labels found on cigarette packages.They comprised one text only warning label used within Nepalese market and eight foreign brand labels. Participants were asked about the impact of the warning labels on: their knowledge of harm from smoking, giving cigarettes as a gift, and quitting smoking. On comparing the Nepalese warning label with other foreign labels with regards to providing knowledge of harm warning, impact of quitting smoking and giving cigarettes as a gift, the overseas labels were found to be more effective. Both smokers and non-smokers thought that warning labels with text plus graphics were substantially more of a deterrent than text-only labels. The findings from this study support previous research that has found that text-plus graphic warning labels were more salient and potentially more effective than text-only labels.Warning labels are one of the component of comprehensive tobacco control and smoking cessation efforts. Stronger warnings on cigarette packages need to be part of a larger Nepalese public health educational efforts.

  14. SURVEY

    DEFF Research Database (Denmark)

    SURVEY er en udbredt metode og benyttes inden for bl.a. samfundsvidenskab, humaniora, psykologi og sundhedsforskning. Også uden for forskningsverdenen er der mange organisationer som f.eks. konsulentfirmaer og offentlige institutioner samt marketingsafdelinger i private virksomheder, der arbejder...

  15. AREA MONITORING OF AMBIENT DOSE RATES IN PARTS OF SOUTH-WESTERN NIGERIA USING A GPS-INTEGRATED RADIATION SURVEY METER.

    Science.gov (United States)

    Okeyode, I C; Rabiu, J A; Alatise, O O; Makinde, V; Akinboro, F G; Al-Azmi, D; Mustapha, A O

    2017-04-01

    A radiation monitoring system comprising a Geiger-Muller counter connected to a smart phone via Bluetooth was used for a dose rate survey in some parts of south-western Nigeria. The smart phone has the Geographical Positioning System, which provides the navigation information and saves it along with the dose rate data. A large number of data points was obtained that shows the dose rate distribution within the region. The results show that the ambient dose rates in the region range from 60 to 520 nSv -1 and showed a bias that is attributable to the influence of geology on the ambient radiation dose in the region. The geology influence was demonstrated by superimposing the dose rate plot and the geological map of the area. The potential applications of the device in determining baseline information and in area monitoring, e.g. for lost or abandoned sources, radioactive materials stockpiles, etc., were discussed in the article, particularly against the background of Nigeria's plan to develop its nuclear power program. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Serological survey for Chagas disease in the rural areas of Manaus, Coari, and Tefé in the Western Brazilian Amazon

    Directory of Open Access Journals (Sweden)

    Belisa Maria Lopes Magalhães

    2011-12-01

    Full Text Available INTRODUCTION: Deforestation, uncontrolled forest, human population migration from endemic areas, and the large number of reservoirs and wild vectors naturally infected by Trypanosoma cruzi promote the endemicity of Chagas disease in the Amazon region. METHODS: We conducted an initial serological survey (ELISA in a sample of 1,263 persons; 1,095 (86.7% were natives of the State of Amazonas, 666 (52.7% were male, and 948 (75.1% were over 20 years old. Serum samples that were found to be reactive, indeterminate, or inconclusive by indirect immunofluorescence (IFI or positive with low titer by IFA were tested by Western blot (WB. Serologically confirmed patients (WB were evaluated in terms of epidemiological, clinical, ECG, and echocardiography characteristics. RESULTS: Fifteen patients had serologically confirmed T. cruzi infection, and 12 of them were autochthonous to the state of Amazonas, for an overall seroprevalence of 1.2% and 0.9% for the state of Amazonas. Five of the 15 cases were males, and the average age was 47 years old; most were farmers with low education. One patient who was not autochthonous, having originated from Alagoas, showed right bundle branch block, bundle branch block, and anterosuperior left ventricular systolic dysfunction with an ejection fraction of 54%. CONCLUSIONS: The results of this study ratify the importance of monitoring CD cases in Amazonia, particularly in the state of Amazonas.

  17. Serological survey for Chagas disease in the rural areas of Manaus, Coari, and Tefé in the Western Brazilian Amazon.

    Science.gov (United States)

    Magalhães, Belisa Maria Lopes; Coelho, Leíla Ines Aguiar Raposo Câmara; Maciel, Marcel Gonçalves; Ferreira, João Marcos Benfica Barbosa; Umezawa, Eufrozina Setsu; Coura, José Rodrigues; Guerra, Jorge Augusto de Oliveira; Barbosa, Maria das Graças Vale

    2011-01-01

    Deforestation, uncontrolled forest, human population migration from endemic areas, and the large number of reservoirs and wild vectors naturally infected by Trypanosoma cruzi promote the endemicity of Chagas disease in the Amazon region. We conducted an initial serological survey (ELISA) in a sample of 1,263 persons; 1,095 (86.7%) were natives of the State of Amazonas, 666 (52.7%) were male, and 948 (75.1%) were over 20 years old. Serum samples that were found to be reactive, indeterminate, or inconclusive by indirect immunofluorescence (IFI) or positive with low titer by IFA were tested by Western blot (WB). Serologically confirmed patients (WB) were evaluated in terms of epidemiological, clinical, ECG, and echocardiography characteristics. Fifteen patients had serologically confirmed T. cruzi infection, and 12 of them were autochthonous to the state of Amazonas, for an overall seroprevalence of 1.2% and 0.9% for the state of Amazonas. Five of the 15 cases were males, and the average age was 47 years old; most were farmers with low education. One patient who was not autochthonous, having originated from Alagoas, showed right bundle branch block, bundle branch block, and anterosuperior left ventricular systolic dysfunction with an ejection fraction of 54%. The results of this study ratify the importance of monitoring CD cases in Amazonia, particularly in the state of Amazonas.

  18. Surveys of Gynaecotyla squatarolae and Microphallus koreana (Digenea: Microphallidae) Metacercariae in Two Species of Estuarine Crabs in Western Coastal Areas, Korea

    Science.gov (United States)

    Lee, Hye Jung; Chai, Jong-Yil; Lee, Jin-Woo; Jin, Ho; Min, Kwan-Hong; Cho, Yong-Jun

    2010-01-01

    To figure out the geographical distribution of Gynaecotyla squatarolae and Microphallus koreana metacercariae in Korea, shore crabs of southwestern coastal areas were examined. Eight coastal areas in Inchon-si (A), Gyeonggi-do (B), Chungcheongnam-do (C, D, and E), Jeollabuk-do (F), and Jeollanam-do (G and H) were selected, and 2 kinds of crabs, Macrophthalmus dilatatus and/or Macrophthalmus japonicus, were caught. After transportation to the laboratory, 15 crabs per each group were grouped and ground in a mortar and pestle, and examined for microphallid metacercariae. In M. dilatatus, G. squatarolae metacercariae were recovered from 3 (C, E, and H) out of 6 regions, but M. koreana metacercariae were not recovered. In the case of M. japonicus, G. squatarolae metacercariae were recovered from 6 (B, D, E, F, G, and H) of 7 areas surveyed, and M. koreana matacercariae were detected from 5 regions (A, B, D, F, and H). These results indicate that the life cycle of G. squatarolae is maintained in the western coastal areas using M. dilatatus and M. japonicus as intermediate hosts, while that of M. koreana is maintained only using M. japonicus. PMID:20333292

  19. Fish survey report of selected impoundments in September 2004

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A fish survey of the following Carolina Sandhills NWR impoundments; Pool L, Lake Bee, Lake 16, Pool G, Mays Lake, Oxpen 1, was conducted in late September of 2004....

  20. Schistosoma bovis in western Uganda.

    Science.gov (United States)

    Stothard, J R; Lockyer, A E; Kabatereine, N B; Tukahebwa, E M; Kazibwe, F; Rollinson, D; Fenwick, A

    2004-09-01

    During routine parasitological surveillance and monitoring activities within a National Control Programme for control of human schistosomiasis in Uganda, it was noted that cattle grazing in a water meadow immediately adjacent to Tonya primary school, where the prevalence of intestinal schistosomiasis in children was in excess of 90%, were unusually emaciated. To test the hypothesis that there may have been an anthropozoonotic focus of Schistosoma mansoni within the local herd, a young female heifer, clearly emaciated and c. 8 months old, was slaughtered from which schistosome worms were later recovered by dissection. As female worms inspected by microscopy were not gravid, morphological identification proved inconclusive but analysis of cytochrome oxidase subunit I (COI) and small subunit (SSU) ribosomal DNA sequences from these worms identified them as Schistosoma bovis Sonsino, 1876. This is the first substantiated report of S. bovis from Lake Albert, western Uganda. Further epidemiological surveys are needed to clarify the extent of bovine schistosomiasis within this region, particularly so since this lakeside plain has been earmarked as a future game reserve.

  1. Using a morpho-functional approach to assess phytoplankton dynamics in two adjacent high-mountain lakes: a 10-year survey

    Directory of Open Access Journals (Sweden)

    Renata Trevisan

    2014-05-01

    Full Text Available Colbricon Superiore and Inferiore are two small adjacent high-mountain lakes located in the Paneveggio Natural Park (Italy. The lakes differ by size and depth while sharing the same bedrock setting and catchment basin. Changes in the phytoplankton communities were studied over a 10-years period to individuate which environmental variables would determine the main differences in biotic assemblages across time and between the two lakes.The study was conducted with fortnightly samplings, assessing the density and biomass of algal taxa. Relationships of each of the biological variables with water temperature, pH, conductivity, transparency, water level, previous week rainfall, and relative water column stability were analyzed by correlation and regression analyses, cluster analysis, and by canonical correspondence analysis. The most significant variables resulted air temperature, hydrologic water level and pH. The smaller Colbricon Inferiore had about double the amount of phytoplankton density and biomass than did the larger Colbricon Superiore. The same lake had higher diversity and lower evenness in structure of the phytoplankton community. Notwithstanding their proximity each lake appears to follow independent species composition dynamics, however parallel patterns were interestingly revealed when data were analyzed by pooling taxa into morpho-functional groups. Morpho-functional groups (MFGs 1b, 3a, 6b, 7a, 9b were differentially most abundant in warm periods, while 2c, 3b, 11c, 5e, 10a prevailed in cold years. MFGs 1b, 2d, 3a and 3b were more characteristic of Lake Colbricon Superiore, while Colbricon Inferiore preferentially featured MFGs 5a, 5e, 9a, 9b, 10a, 11a and 8a. The role of the meteo-climatic parameters was pointed out in driving the different patterns observed in the two lakes.

  2. Prevalence and correlates of tobacco use amongst junior collegiates in twin cities of western Nepal: A cross-sectional, questionnaire-based survey

    Directory of Open Access Journals (Sweden)

    Paudel Jagadish

    2008-03-01

    Full Text Available Abstract Background College students are vulnerable to tobacco addiction. Tobacco industries often target college students for marketing. Studies about prevalence of tobacco use and its correlates among college students in Nepal are lacking. Methods A cross-sectional survey was carried out in two cities of western Nepal during January-March, 2007. A pre-tested, anonymous, self-administered questionnaire (in Nepali adapted from Global Youth Tobacco Survey (GYTS and a World Bank study was administered to a representative sample of 1600 students selected from 13 junior colleges by two-stage stratified random sampling. Results Overall prevalence of 'ever users' of tobacco products was 13.9%. Prevalence among boys and girls was 20.5% and 2.9% respectively. Prevalence of 'current users' was 10.2% (cigarette smoking: 9.4%, smokeless products: 6.5%, and both forms: 5.7%. Median age at initiation of cigarette smoking and chewable tobacco was 16 and 15 years respectively. Among the current cigarette smokers, 58.7% (88/150 were smoking at least one cigarette per day. Most (67.8% 'Current users' purchased tobacco products by themselves from stores or got them from friends. Most of them (66.7% smoked in tea stalls or restaurants followed by other public places (13.2%. The average daily expenditure was 20 Nepalese rupees (~0.3 USD and most (59% students reported of having adequate money to buy tobacco products. Majority (82% of the students were exposed to tobacco advertisements through magazines/newspapers, and advertising hoardings during a period of 30 days prior to survey. The correlates of tobacco use were: age, gender, household asset score and knowledge about health risks, family members, teachers and friends using tobacco products, and purchasing tobacco products for family members. Conclusion School/college-based interventions like counseling to promote cessation among current users and tobacco education to prevent initiation are necessary

  3. Mapping of the total magnetic field in the area of Lake Balaton

    Science.gov (United States)

    Visnovitz, Ferenc; Hegyi, Betti; Raveloson, Andrea; Rozman, Gábor; Lenkey, László; Kovács, Péter; Csontos, András; Heilig, Balázs; Horváth, Ferenc

    2017-04-01

    The Lake Balaton with 600 km2 area represents the largest lake in Central Europe and a blank spot on the magnetic anomaly map of Hungary. It is because the construction of the Hungarian magnetic anomaly map dates back to the 1960s and relied mainly on classical vertical-field balance surveys. To fill the gap, we initiated a systematic mapping using modern magnetometers and positioning system in the framework of a complex geophysical study of Lake Balaton (National Research Project 109255 K). The main goal of this study has been to identify subvolcanic bodies and tectonic structures below the lake and correlate them with well-known features mapped onshore in the vicinity of Balaton. During the magnetic survey an Overhauser field magnetometer (GEM System, GSM-19) was mounted on a plastic boat and towed behind a motorboat in a distance of 20 m with a speed of 6 to 16 km/h depending on weather conditions. Tests measurements showed that at this distance the magnetic noise generated by the motorboat was negligible. We measured total field values with a sampling interval of 1 to 2 s. As a result, the whole lake has been covered by magnetic profiles in an orthogonal grid with spacing of 1 km. During data interpretation we applied for correction of temporal variation of magnetic field registered in the Tihany Geophysical Observatory and normal field correction from a regional model. The final anomaly map in the western part of the lake shows anomalies with amplitudes of 20 to 60 nT and a half wavelength of 0.5 to 1 km. A larger feature was recognized related to the Badacsony Hill a major basaltic bute at the northern shore of the lake. In the middle part of the lake the total field is rather smooth, no significant anomaly has been revealed. However, slight disturbances can be noticed in the proximity of a neotectonic fault zone mapped by high resolution seismic data. In the eastern part of the lake few low amplitude (5-20 nT) anomalies have been observed that are associated

  4. Status of important prey fishes in the U.S. waters of Lake Ontario, 2013: Introduction and methods, alewife, rainbow smelt, sculpins, and round goby

    Science.gov (United States)

    Walsh, Maureen; Weidel, Brian C.; Connerton, Michael J.

    2014-01-01

    Lake Ontario has a mean depth of 86 m (282 ft) and a maximum depth of 244 m (801 ft) (Herdendorf 1982). The southern, New York portion of the lake has the deepest water (Figure 1). In New York waters, about 67% of the lake is lake is Lake Ontario prey fishes each year since 1978. Bottom trawl assessments were initially focused on Alewife Alosa pseudoharengus (April), Rainbow Smelt Osmerus mordax (June), and Slimy Sculpin Cottus cognatus (October). Seasonal survey timing corresponded to the peak catches in 1972 when collections were made every month May to October (Owens et al. 2003). Twelve transects were established at approximately 25-km intervals along the U.S. shoreline (Figure 2). Alewife assessment was conducted at all transects, Rainbow Smelt assessment at all transects except Fair Haven, and six transects representing eastern, southern, and western lake areas were sampled for Slimy Sculpin (Figure 2). Changes in the Lake Ontario ecosystem (species invasion, oligotrophication, native species rebound) require ongoing evaluation of current methods which sometimes necessitate redistribution of trawl effort, or changes in sampling designs and/or gear. For instance, the spring Alewife assessment is now used also to assess invasive Round Goby Neogobius melanostomus population dynamics. Likewise, the fall benthic fish assessment (formerly sculpin assessment) now also tracks dynamics of the rebounding native Deepwater Sculpin Myoxocephalus thompsonii population, the apparent declining population of Slimy Sculpin, and fall distribution of Round Goby.

  5. Playa Lakes

    Data.gov (United States)

    Kansas Data Access and Support Center — This digital dataset provides information about the spatial distribution of soil units associated with playa lakes. Specific soil types have been designated by the...

  6. Lake Cadagno

    DEFF Research Database (Denmark)

    Tonolla, Mauro; Storelli, Nicola; Danza, Francesco

    2017-01-01

    Lake Cadagno (26 ha) is a crenogenic meromictic lake located in the Swiss Alps at 1921 m asl with a maximum depth of 21 m. The presence of crystalline rocks and a dolomite vein rich in gypsum in the catchment area makes the lake a typical “sulphuretum ” dominated by coupled carbon and sulphur...... cycles. The chemocline lies at about 12 m depth, stabilized by density differences of salt-rich water supplied by sub-aquatic springs to the monimolimnion and of electrolyte-poor surface water feeding the mixolimnion. Steep sulphide and light gradients in the chemocline support the growth of a large...... in the chemocline. Small-celled PSB together with the sulfate-reducing bacterium Desulfocapsa thiozymogenes sp. form stable aggregates in the lake, which represent small microenvironments with an internal sulphur cycle. Eukaryotic primary producers in the anoxic zones are dominated by Cryptomonas phaseolus...

  7. BATHYMETRIC STUDY OF WADI EL-RAYAN LAKES, EGYPT

    Directory of Open Access Journals (Sweden)

    Radwan Gad Elrab ABD ELLAH

    2016-12-01

    Full Text Available Bathymetry is a technique of measuring depths to determine the morphometry of water bodies. The derivation of bathymetry from the surveys is one of the basic researches of the aquatic environment, which has several practical implications to on the lake environment and it's monitoring. Wadi El-Rayan, as Ramsar site, is a very important wetland, in Egypt, as a reservoir for agricultural drainage water, fisheries and tourism. The Lakes are man-made basins in the Fayoum depression. Wadi El-Rayan Lakes are two reservoirs (upper Lake and Lower Lake, at different elevations. The Upper Lake is classified as open basin, while the Lower Lake is a closed basin, with no significant obvious water outflow. During recent decades, human impact on Wadi El-Rayan Lakes has increased due to intensification of agriculture and fish farming. Analyses of bathyemtric plans from 1996, 2010 and 2016 showed, the differences between morphometric parameters of the Upper Lake were generally small, while the Lower Lake changes are obvious at the three periods. The small fluctuate, in the features of Upper Lake is due to the water balance between the water inflow and water. The Lower Lake has faced extreme water loss through last twenty years is due to the agricultural lands and fish farms extended in the depression. The Upper Lake is rich in Lakeshores macrophyets, while decline the water plants in the Lower Lake. With low water levels, in the Lower Lake, the future continuity of the Lake system is in jeopardy

  8. Discrimination among spawning concentrations of Lake Superior lake herring based on trace element profiles in sagittae

    Science.gov (United States)

    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.

  9. Serologic survey for selected viral pathogens in free-ranging endangered European mink (Mustela lutreola) and other mustelids from south-western France.

    Science.gov (United States)

    Philippa, Joost; Fournier-Chambrillon, Christine; Fournier, Pascal; Schaftenaar, Willem; van de Bildt, Marco; van Herweijnen, Rob; Kuiken, Thijs; Liabeuf, Marie; Ditcharry, Sébastien; Joubert, Laurent; Bégnier, Michel; Osterhaus, Ab

    2008-10-01

    To investigate the possible role of selected pathogens in the decline of endangered European mink (Mustela lutreola) populations and the potential for these pathogens to affect mink survival, a serologic survey was conducted using serum samples collected from March 1996 to March 2003 in eight departments of south-western France. In total, 481 free-ranging individuals of five mustelid species (including the European mink) were tested. Sympatric mustelids can serve as sentinels to determine the presence of antibodies to viruses in the study area that could potentially infect mink. Antibodies to Canine distemper virus (CDV) were detected in all species; 9% of 127 European mink, 20% of 210 polecats (Mustela putorius), 5% of 112 American mink (Mustela vison), 33% of 21 stone marten (Martes foina) and 5% of 20 pine marten (Martes martes). Antibody prevalence was significantly higher in stone marten and polecats, possibly because their ranges overlap more closely with that of domestic species than that of the other species tested. Antibodies to Canine adenovirus were detected in all species but the pine marten; antibody prevalence estimates ranging from 2% to 10%. Antibodies to canine parainfluenza virus were detected in 1% of European mink, 1% of American mink and 5% of tested polecats but were not detected in Martes species. Antibodies to Rabies virus (RV) were detected in three animals, possibly because of interspecies transmission of bat lyssaviruses as the sampling area is considered to be free of RV, or to a lack of test specificity, as antibody titers were low. The high antibody prevalence to potentially lethal CDV suggests that this pathogen could have significant effects on the free-ranging populations and has implications for the conservation efforts for the endangered European mink.

  10. Ethnobotanical survey of medicinal plants used to manage High Blood Pressure and Type 2 Diabetes Mellitus in Bitterfontein, Western Cape Province, South Africa.

    Science.gov (United States)

    Davids, Denver; Gibson, Diana; Johnson, Quinton

    2016-12-24

    The aim of this study was to identify and document medicinal plants used to manage High Blood Pressure and Type 2 Diabetes Mellitus in Bitterfontein, Western Cape Province, South Africa. One hundred and twelve (112) respondents were interviewed between August 2014 and September 2015 through semi-structured surveys to gather data on the percentage of people who had been diagnosed with High Blood Pressure and/or Type 2 Diabetes Mellitus and to determine the frequency of medicinal plant and allopathic medicine use. Twelve (12) key respondents were subsequently selected, using a non-probability snowball sampling method. They were interviewed in-depth concerning their plant practices and assisted with plant collection. Twenty-four plant (24) species belonging to 15 families were identified for the management of High Blood Pressure and Type 2 Diabetes Mellitus. The most frequently reported families were Asteraceae (20.8%), Lamiaceae (16.67%), Crassulaceae (8.33%) and Aizoaceae (8.33%). The remaining (45.54%) were evenly split over eleven families- Fabaceae, Amaryllidaceae, Anacardiaceae, Capparaceae, Geraniaceae, Apiaceae, Convolvulaceae, Apocynaceae, Rutaceae, Asphodelaceae and Thymelaeaceae. The most commonly used plant species overall was Lessertia frutescens (96.55%). The most frequently used plant parts included leaves (57.63%) roots/bulbs (15.25%) and stems (11.86%), mostly prepared as infusions or decoctions for oral administration. Medicinal plants are widely used by High Blood Pressure and Type 2 Diabetes Mellitus sufferers. They employ diverse plant species to manage both conditions. In addition, some sufferers often use prescribed allopathic medication, as well as medicinal plants, but at different intervals. Despite high usage the plants identified are not currently threatened (Red Data list status: least concern). Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  11. Does anti-malarial drug knowledge predict anti-malarial dispensing practice in drug outlets? A survey of medicine retailers in western Kenya

    Directory of Open Access Journals (Sweden)

    Rusk Andria

    2012-08-01

    Full Text Available Abstract Background Malaria is a major cause of morbidity and mortality in Kenya, where it is the fifth leading cause of death in both children and adults. Effectively managing malaria is dependent upon appropriate treatment. In Kenya, between 17 to 83 percent of febrile individuals first seek treatment for febrile illness over the counter from medicine retailers. Understanding medicine retailer knowledge and behaviour in treating suspected malaria and dispensing anti-malarials is crucial. Methods To investigate medicine retailer knowledge about anti-malarials and their dispensing practices, a survey was conducted of all retail drug outlets that sell anti-malarial medications and serve residents of the Webuye Health and Demographic Surveillance Site in the Bungoma East District of western Kenya. Results Most of the medicine retailers surveyed (65% were able to identify artemether-lumefantrine (AL as the Kenyan Ministry of Health recommended first-line anti-malarial therapy for uncomplicated malaria. Retailers who correctly identified this treatment were also more likely to recommend AL to adult and paediatric customers. However, the proportion of medicine retailers who recommend the correct treatment is disappointingly low. Only 48% would recommend AL to adults, and 37% would recommend it to children. It was discovered that customer demand has an influence on retailer behaviour. Retailer training and education were found to be correlated with anti-malarial drug knowledge, which in turn is correlated with dispensing practices. Medicine retailer behaviour, including patient referral practice and dispensing practices, are also correlated with knowledge of the first-line anti-malarial medication. The Kenya Ministry of Health guidelines were found to influence retailer drug stocking and dispensing behaviours. Conclusion Most medicine retailers could identify the recommended first-line treatment for uncomplicated malaria, but the percentage that could

  12. White Lake AOC

    Science.gov (United States)

    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.

  13. Limnology of southern African coastal lakes — new vistas from ...

    African Journals Online (AJOL)

    Characteristically relict estuarine/marine fauna (a calanoid copepod, crown crab, amphipod and fish) were present in two oligotrophic lakes, including the largest — putatively a drowned-valley lake. ... Survey findings were used to assess the suitability of these lakes as prospective habitats for exotic grass and silver carp.

  14. Geologic map database of the El Mirage Lake area, San Bernardino and Los Angeles Counties, California

    Science.gov (United States)

    Miller, David M.; Bedford, David R.

    2000-01-01

    This geologic map database for the El Mirage Lake area describes geologic materials for the dry lake, parts of the adjacent Shadow Mountains and Adobe Mountain, and much of the piedmont extending south from the lake upward toward the San Gabriel Mountains. This area lies within the western Mojave Desert of San Bernardino and Los Angeles Counties, southeastern California. The area is traversed by a few paved highways that service the community of El Mirage, and by numerous dirt roads that lead to outlying properties. An off-highway vehicle area established by the Bureau of Land Management encompasses the dry lake and much of the land north and east of the lake. The physiography of the area consists of the dry lake, flanking mud and sand flats and alluvial piedmonts, and a few sharp craggy mountains. This digital geologic map database, intended for use at 1:24,000-scale, describes and portrays the rock units and surficial deposits of the El Mirage Lake area. The map database was prepared to aid in a water-resource assessment of the area by providing surface geologic information with which deepergroundwater-bearing units may be understood. The area mapped covers the Shadow Mountains SE and parts of the Shadow Mountains, Adobe Mountain, and El Mirage 7.5-minute quadrangles. The map includes detailed geology of surface and bedrock deposits, which represent a significant update from previous bedrock geologic maps by Dibblee (1960) and Troxel and Gunderson (1970), and the surficial geologic map of Ponti and Burke (1980); it incorporates a fringe of the detailed bedrock mapping in the Shadow Mountains by Martin (1992). The map data were assembled as a digital database using ARC/INFO to enable wider applications than traditional paper-product geologic maps and to provide for efficient meshing with other digital data bases prepared by the U.S. Geological Survey's Southern California Areal Mapping Project.

  15. Suppression of invasive lake trout in an isolated backcountry lake in Glacier National Park

    Science.gov (United States)

    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.

  16. Sea lamprey mark type, marking rate, and parasite-host relationships for lake trout and other species in Lake Ontario

    Science.gov (United States)

    Lantry, Brian F.; Adams, Jean V.; Christie, Gavin; Schaner, Teodore; Bowlby, James; Keir, Michael; Lantry, Jana; Sullivan, Paul; Bishop, Daniel; Treska, Ted; Morrison, Bruce

    2015-01-01

    We examined how attack frequency by sea lampreys on fishes in Lake Ontario varied in response to sea lamprey abundance and preferred host abundance (lake trout > 433 mm). For this analysis we used two gill net assessment surveys, one angler creel survey, three salmonid spawning run datasets, one adult sea lamprey assessment, and a bottom trawl assessment of dead lake trout. The frequency of fresh sea lamprey marks observed on lake trout from assessment surveys was strongly related to the frequency of sea lamprey attacks observed on salmon and trout from the creel survey and spawning migrations. Attack frequencies on all salmonids examined were related to the ratio between the abundances of adult sea lampreys and lake trout. Reanalysis of the susceptibility to sea lamprey attack for lake trout strains stocked into Lake Ontario reaffirmed that Lake Superior strain lake trout were among the most and Seneca Lake strain among the least susceptible and that Lewis Lake strain lake trout were even more susceptible than the Superior strain. Seasonal attack frequencies indicated that as the number of observed sea lamprey attacks decreased during June–September, the ratio of healing to fresh marks also decreased. Simulation of the ratios of healing to fresh marks indicated that increased lethality of attacks by growing sea lampreys contributed to the decline in the ratios and supported laboratory studies about wound healing duration.

  17. Loss of glutathione S-transferases in pollution-associated liver neoplasms in white suckers (Catostomus commersoni) from Lake Ontario

    National Research Council Canada - National Science Library

    Stalker, M J; Kirby, G M; Kocal, T E; Smith, I R; Hayes, M A

    1991-01-01

    White suckers (Catostomus commersoni) are one of two species of bottom-feeding fish in which various liver neoplasms are more prevalent in urban/industrial sites in western Lake Ontario than in less polluted sites in the Great Lakes...

  18. Diet of lake trout and burbot in northern Lake Michigan during spring: Evidence of ecological interaction

    Science.gov (United States)

    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. Reformatted Hypack Navigation from Lake Mead - 2000

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Lake Mead is a large interstate reservoir located in the Mojave Desert of southeastern Nevada and northwestern Arizona. It was impounded in 1935 by the construction...

  20. Reformatted Navigation from Lake Mead - 1999

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Lake Mead is a large interstate reservoir located in the Mojave Desert of southeastern Nevada and northwestern Arizona. It was impounded in 1935 by the construction...

  1. Prescribed fire monitoring protocol : Medicine Lake NWR

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Initial Survey Instructions for prescribed fire monitoring at Medicine Lake National Wildlife Refuge. Instructions contain methods on data collection, an equipment...

  2. Reformatted Hypack Navigation from Lake Mead - 2001

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Lake Mead is a large interstate reservoir located in the Mojave Desert of southeastern Nevada and northwestern Arizona. It was impounded in 1935 by the construction...

  3. Combining lake and watershed characteristics with Landsat TM data for remote estimation of regional lake clarity

    Science.gov (United States)

    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

  4. Cooperative science to inform Lake Ontario management: Research from the 2013 Lake Ontario CSMI program

    Science.gov (United States)

    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.

  5. Distribution of native mussel (unionidae) assemblages in coastal areas of Lake Erie, Lake St. Clair, and connecting channels, twenty-five years after a dreissenid invasion

    Science.gov (United States)

    Zanatta, David T.; Bossenbroek, Jonathan M.; Burlakova, Lyubov E.; Crail, Todd D.; Szalay, Ferenc de; Griffith, Traci A.; Kapusinski, Douglas; Karatayev, Alexander Y.; Krebs, Robert A.; Meyer, Elizabeth S.; Paterson, Wendy L.; Prescott, Trevor J.; Rowe, Matthew T.; Schloesser, Donald W.; Walsh, Mary C.

    2015-01-01

    Over the past 25 years, unionid mussels in the Laurentian Great Lakes of North America have been adversely impacted by invasive dreissenid mussels, which directly (e.g., by attachment to unionid shells) and indirectly (e.g., by competing for food) cause mortality. Despite the invasion, unionids have survived in several areas in the presence of dreissenid mussels. We investigated current spatial patterns in these native mussel refuges based on surveys for unionid mussels across 48 sampling locations (141 sites) in 2011 and 2012, and documented species abundance and diversity in coastal areas of lakes St. Clair and Erie. The highest-quality assemblages of native mussels (densities, richness, and diversity) appear to be concentrated in the St. Clair delta, where abundance continues to decline, as well as in in Thompson Bay of Presque Isle in Lake Erie and in just a few coastal wetlands and drowned river-mouths in the western basin of Lake Erie. The discovery of several new refuge areas suggests that unionids have a broader distribution within the region than previously thought.

  6. Western Sufism

    DEFF Research Database (Denmark)

    Sedgwick, Mark

    Western Sufism is sometimes dismissed as a relatively recent "new age" phenomenon, but in this book, Mark Sedgwick argues that it actually has very deep roots, both in the Muslim world and in the West. In fact, although the first significant Western Sufi organization was not established until 1915...... to the internet, Mark Sedgwick demonstrates that the phenomenon of Western Sufism not only draws on centuries of intercultural transfers, but is also part of a long-established relationship between Western thought and Islam that can be productive, not confrontational....

  7. In-lake processes offset increased terrestrial inputs of dissolved organic carbon and color to lakes.

    Directory of Open Access Journals (Sweden)

    Stephan J Köhler

    Full Text Available Increased color in surface waters, or browning, can alter lake ecological function, lake thermal stratification and pose difficulties for drinking water treatment. Mechanisms suggested to cause browning include increased dissolved organic carbon (DOC and iron concentrations, as well as a shift to more colored DOC. While browning of surface waters is widespread and well documented, little is known about why some lakes resist it. Here, we present a comprehensive study of Mälaren, the third largest lake in Sweden. In Mälaren, the vast majority of water and DOC enters a western lake basin, and after approximately 2.8 years, drains from an eastern basin. Despite 40 years of increased terrestrial inputs of colored substances to western lake basins, the eastern basin has resisted browning over this time period. Here we find the half-life of iron was far shorter (0.6 years than colored organic matter (A₄₂₀; 1.7 years and DOC as a whole (6.1 years. We found changes in filtered iron concentrations relate strongly to the observed loss of color in the western basins. In addition, we observed a substantial shift from colored DOC of terrestrial origin, to less colored autochthonous sources, with a substantial decrease in aromaticity (-17% across the lake. We suggest that rapid losses of iron and colored DOC caused the limited browning observed in eastern lake basins. Across a wider dataset of 69 Swedish lakes, we observed greatest browning in acidic lakes with shorter retention times (< 1.5 years. These findings suggest that water residence time, along with iron, pH and colored DOC may be of central importance when modeling and projecting changes in brownification on broader spatial scales.

  8. Modern non-pollen palynomorphs from East African Lake sediments

    NARCIS (Netherlands)

    Gelorini, V.; Verbeken, A.; van Geel, B.; Cocquyt, C.; Verschuren, D.

    2011-01-01

    This paper presents an illustrated guide to the identification of non-pollen palynomorphs (NPPs) preserved in lake-sediment archives from equatorial East Africa. Modern NPPs were recovered from recently deposited surface sediment in 20 small crater lakes in western Uganda, located along

  9. U-Pb isochron age and Pb isotope systematics of the Golden Fleece vein - implications for the relationship of mineralization to the Lake City caldera, western San Juan Mountains, Colorado.

    Science.gov (United States)

    Hon, K.; Ludwig, K. R.; Simmons, K.R.; Slack, J.F.; Grauch, R.I.

    1985-01-01

    A U/Pb isochron age of 27.5 + or - 0.5 m.y. is determined for the Golden Fleece vein, an age which is identical with the age of the quartz latite lavas that the vein cuts. Within the Lake City area, only the Golden Fleece vein contains pitchblende and Au-Ag tellurides and has Pb isotope ratios that together define it as unique within the area. The 27.5 m.y. age relates this vein to the waning stages of the Uncompahgre caldera (27-29) rather than to the Lake City caldera (23.1 m.y.). -G.J.N.

  10. Potential nitrate removal in a coastal freshwater sediment (Haringvliet Lake, The Netherlands) and response to salinization

    NARCIS (Netherlands)

    Laverman, A.M.; Canavan, R.W.; Slomp, C.P.; Van Cappellen, P.

    2007-01-01

    Nitrogen transformations and their response to salinization were studied in bottom sediment of a coastal freshwater lake (Haringvliet Lake, The Netherlands). The lake was formed as the result of a river impoundment along the south-western coast of the Netherlands, and is currently targeted for

  11. Great Lakes

    Science.gov (United States)

    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

  12. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the North Canadian River from Canton Lake to Lake Overholser in central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital water-level elevation contours for the alluvial and terrace deposits along the North Canadian River from Canton Lake to Lake...

  13. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the North Canadian River from Canton Lake to Lake Overholser in central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital aquifer boundaries for the alluvial and terrace deposits along the North Canadian River from Canton Lake to Lake Overholser in...

  14. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the North Canadian River from Canton Lake to Lake Overholser in central Oklahoma

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital polygons of a constant recharge value for the alluvial and terrace deposits along the North Canadian River from Canton Lake to Lake...

  15. Optical remote sensing of lakes: an overview on Lake Maggiore

    Directory of Open Access Journals (Sweden)

    Claudia Giardino

    2013-08-01

    Full Text Available Optical satellite remote sensing represents an opportunity to integrate traditional methods for assessing water quality of lakes: strengths of remote sensing methods are the good spatial and temporal coverage, the possibility to monitor many lakes simultaneously and the reduced costs. In this work we present an overview of optical remote sensing techniques applied to lake water monitoring. Then, examples of applications focused on lake Maggiore, the second largest lake in Italy are discussed by presenting the temporal trend of chlorophyll-a (chl-a, suspended particulate matter (SPM, coloured dissolved organic matter (CDOM and the z90 signal depth (the latter indicating the water depth from which 90% of the reflected light comes from as estimated from the images acquired by the Medium Resolution Imaging Spectrometer (MERIS in the pelagic area of the lake from 2003 to 2011. Concerning the chl-a trend, the results are in agreement with the concentration values measured during field surveys, confirming the good status of lake Maggiore, although occasional events of water deterioration were observed (e.g., an average increase of chl-a concentration, with a decrease of transparency, as a consequence of an anomalous phytoplankton occurred in summer 2011. A series of MERIS-derived maps (summer period 2011 of the z90 signal are also analysed in order to show the spatial variability of lake waters, which on average were clearer in the central pelagic zones. We expect that the recently launched (e.g., Landsat-8 and the future satellite missions (e.g., Sentinel-3 carrying sensors with improved spectral and spatial resolution are going to lead to a larger use of remote sensing for the assessment and monitoring of water quality parameters, by also allowing further applications (e.g., classification of phytoplankton functional types to be developed.

  16. The preglacial sediment record of Lake Ladoga, NW Russia - first results from a multi-proxy study on a 23 m sediment record

    Science.gov (United States)

    Gromig, R.; Melles, M.; Wagner, B.; Krastel, S.; Andreev, A.; Fedorov, G.; Just, J.; Wennrich, V.; Savelieva, L.; Subetto, D.; Shumilovskikh, L.

    2016-12-01

    The joint German-Russian project 'PLOT - Paleolimnological Transect' aims to recover lake sediment sequences along a more than 6000 km long longitudinal transect across the Eurasian Arctic in order to study the Late Quaternary climatic and environmental history. The eastern end of the PLOT transect is formed by the well-studied record from Lake El'gygytgyn (NE Siberia). Lake Ladoga (N 60°50' E 31°30') is Europe's largest lake, both by size and volume and forms the westernmost end of the transect. Whereas modern sedimentation as well as the Holocene and Late Glacial history of Lake Ladoga have intensely been studied, the preglacial history of the lake is poorly studied to date by sediment cores drilled in the 1930's. A seismic survey of Lake Ladoga in summer 2013 revealed unconformities in the western lake basin, which may separate preglacial sediments in isolated depressions from Late Glacial and Holocene sediment successions above. A 23 m long sediment core (Co1309) was retrieved from one of these depressions. Core Co1309 was investigated by XRF-scanning, magnetic susceptibility measurements, as well as pollen, grain-size, and bio-geochemical analyses. An age-depth model combining radiocarbon, OSL, and paleomagnetic dates is in progress. Both, the pollen results and the OSL ages from the base of the record indicate a deposition during MIS 5e (Eemian). The well sorted reddish sands from this interval contain dinoflagellates suggesting at least brackish conditions, likely due to the existence of a gateway connecting a precursor of the Baltic Sea with the White Sea via Lake Ladoga. The Late Glacial sequence consists of greyish varved clays of decreasing thickness upwards with sporadically intercalated sand layers. The Holocene sequence is composed of brownish diatomaceous silty clay with minor proportions of sand.

  17. Continuous water-quality monitoring to improve lake management at Lake Mattamuskeet National Wildlife Refuge

    Science.gov (United States)

    Michelle Moorman; Tom Augspurger

    2016-01-01

    The U.S. Fish and Wildlife Service has partnered with U.S. Geological Survey to establish 2 continuous water-quality monitoring stations at Lake Mattamuskeet. Stations on the east and west side of the lake measure water level, clarity, dissolved oxygen, pH, temperature, salinity, and conductivity.

  18. Great Lakes Research Vessel Operations 1958-2016: Trawl

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — All trawl data represented here expand upon vessel operations (OP table) data, all of which are collected by the United States Geological Survey, Great Lakes Science...

  19. Great Lakes Research Vessel Operations 1958-2016: Mysis

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — All mysis data represented here expand upon vessel operations (OP table) data, all of which are collected by the United States Geological Survey, Great Lakes Science...

  20. Great Lakes Research Vessel Operations 1958-2016: Mensuration

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — All mensuration data represented here expand upon vessel operations (OP table) data, all of which are collected by the United States Geological Survey, Great Lakes...