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Sample records for site antelope lake

  1. Closure Letter Report for Corrective Action Unit 496: Buried Rocket Site - Antelope Lake (TTR)

    International Nuclear Information System (INIS)

    NSTec Environmental Restoration

    2007-01-01

    A Streamlined Approach for Environmental Restoration (SAFER) Plan for investigation and closure of CAU 496, Corrective Action Site (CAS) TA-55-008-TAAL (Buried Rocket), at the Tonopah Test Range (TTR), was approved by the Nevada Department of Environmental Protection (NDEP) on July 21,2004. Approval to transfer CAS TA-55-008-TAAL from CAU 496 to CAU 4000 (No Further Action Sites) was approved by NDEP on December 21, 2005, based on the assumption that the rocket did not present any environmental concern. The approval letter included the following condition: ''NDEP understands, from the NNSA/NSO letter dated November 30,2005, that a search will be conducted for the rocket during the planned characterization of other sites at the Tonopah Test Range and, if found, the rocket will be removed as a housekeeping measure''. NDEP and U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office personnel located the rocket on Mid Lake during a site visit to TTR, and a request to transfer CAS TA-55-008-TAAL from CAU 4000 back to CAU 496 was approved by NDEP on September 11,2006. CAS TA-55-008-TAAL was added to the ''Federal Facility Agreement and Consent Order'' of 1996, based on an interview with a retired TTR worker in 1993. The original interview documented that a rocket was launched from Area 9 to Antelope Lake and was never recovered due to the high frequency of rocket tests being conducted during this timeframe. The interviewee recalled the rocket being an M-55 or N-55 (the M-50 ''Honest John'' rocket was used extensively at TTR from the 1960s to early 1980s). A review of previously conducted interviews with former TTR personnel indicated that the interviewees confused information from several sites. The location of the CAU 496 rocket on Mid Lake is directly south of the TTR rocket launch facility in Area 9 and is consistent with information gathered on the lost rocket during recent interviews. Most pertinently, an interview in 2005 with a

  2. Roan antelope ( Hippotragus equinus desmarest1804) food plants ...

    African Journals Online (AJOL)

    The habitat changes in Borgu sector of Kainji lake National Park affects the food plants and feeding habits of roan antelope. The changes which are usually seasonal variation in climate and the effect of uncontrolled bush burning by poachers. The objectives of the study were to determine the food plants and feeding habits ...

  3. Improvements to Web Toolkits for Antelope-based Real-time Monitoring Systems

    Science.gov (United States)

    Lindquist, K. G.; Newman, R. L.; Vernon, F. L.; Hansen, T. S.; Orcutt, J.

    2005-12-01

    The Antelope Environmental Monitoring System (http://www.brtt.com) is a robust middleware architecture for near-real-time data collection, analysis, archiving and distribution. Antelope has an extensive toolkit allowing users to interact directly with their datasets. A rudimentary interface was developed in previous work between Antelope and the web-scripting language PHP (The PHP language is described in more detail at http://www.php.net). This interface allowed basic application development for remote access to and interaction with near-real-time data through a World Wide Web interface. We have added over 70 new functions for the Antelope interface to PHP, providing a solid base for web-scripting of near-real-time Antelope database applications. In addition, we have designed a new structure for web sites to be created from the Antelope platform, including PHP applications and Perl CGI scripts as well as static pages. Finally we have constructed the first version of the dbwebproject program, designed to dynamically create and maintain web-sites from specified recipes. These tools have already proven valuable for the creation of web tools for the dissemination of and interaction with near-real-time data streams from multi-signal-domain real-time sensor networks. We discuss current and future directions of this work in the context of the ROADNet project. Examples and applications of these core tools are elaborated in a companion presentation in this session (Newman et al., AGU 2005, session IN06).

  4. Strontium-90 concentrations in pronghorn antelope bones near a nuclear fuel reprocessing plant

    International Nuclear Information System (INIS)

    Markham, O.D.; Halford, D.K.

    1980-01-01

    Metacarpal bones were collected from pronghorn antelope near a nuclear fuel reprocessing plant and adjacent areas on the Idaho National Engineering Laboratory (INEL) Site in Southeastern Idaho. Control bones were collected from offsite animals at higher elevations. Average concentrations in metacarpals were 9.6+-2.8(SE) pCi/g(ash) within 10 km of the Idaho Chemical Processing Plant (ICPP), 4.0+-0.9pCi/g for animals on the remainder of the INEL Site and 5.5+-1.0pCi/g for control animals. ICPP atmospheric releases of 90 Sr appeared to have caused a significant (P 90 Sr concentrations in antelope bones within 10 km of the ICPP as compared to bones of other INEL antelope. However, the ICPP antelope bone 90 Sr concentrations were not statistically different from that occurring in bones of the control animals from higher elevations. Antelope near the ICPP received approximately double the radiation dose to bone compared to doses received by other INEL antelope as a result of 90 Sr in bone. Strontium-90 in bone from both fallout and ICPP sources resulted in an estimated average radiation dose of 40 mrad/yr to edosteal cells and 20 mrad/yr to active bone marrow. (author)

  5. The presence and distribution of polycyclic aromatic hydrocarbons and inorganic elements in water and lakebed materials and the potential for bioconcentration in biota at established sampling sites on Lake Powell, Utah and Arizona

    Science.gov (United States)

    Schonauer, Kurt T.; Hart, Robert J.; Antweiler, Ronald C.

    2014-01-01

    The National Park Service is responsible for monitoring the effects of visitor use on the quality of water, lakebed material (bottom sediments), and biota, in Lake Powell, Utah and Arizona. A sampling program was begun in 2010 to assess the presence, distribution, and concentrations of organic and inorganic compounds in the water column and bottom sediment. In response to an Environmental Impact Statement regarding personal watercraft and as a continuation from previous studies by the U.S. Geological Survey and the National Park Service, Glen Canyon National Recreation Area, water samples were collected and analyzed for polycyclic aromatic hydrocarbons (PAHs) using semipermeable membrane devices and inorganic elements using a fixed-bottle sampler deployed at established monitoring sites during 2010 and 2011. Lakebed material samples were also analyzed for polycyclic aromatic hydrocarbons and inorganic elements, some of which could be harmful to aquatic biota if present at concentrations above established aquatic life criteria. Of the 44 PAH compounds analyzed, 26 individual compounds were detected above the censoring limit in the water column by semipermeable membrane devices. The highest number of compounds detected were at Lone Rock Beach, Wahweap Marina, Rainbow Bridge National Monument, and Antelope Marina which are all located in the southern part of Lake Powell where visitation and boat use is high. Because PAHs can remain near their source, the potential for bioconcentration is highest near these sites. The PAH compound found in the highest concentration was phenol (5,902 nanograms per liter), which is included in the U.S. Environmental Protection Agency’s priority pollutants list. The dissolved inorganic chemistry of water samples measured at the sampling sites in Lake Powell defined three different patterns of elements: (1) concentrations were similar between sites in the upper part of the lake near Farley Canyon downstream to Halls Crossing Marina, a

  6. Drowsy cheetah hunting antelopes: a diffusing predator seeking fleeing prey

    Science.gov (United States)

    Winkler, Karen; Bray, Alan J.

    2005-02-01

    We consider a system of three random walkers (a 'cheetah' surrounded by two 'antelopes') diffusing in one dimension. The cheetah and the antelopes diffuse, but the antelopes experience in addition a deterministic relative drift velocity, away from the cheetah, proportional to their distance from the cheetah, such that they tend to move away from the cheetah with increasing time. Using the backward Fokker-Planck equation we calculate, as a function of their initial separations, the probability that the cheetah has caught neither antelope after infinite time.

  7. Groundwater quality in the Antelope Valley, California

    Science.gov (United States)

    Dawson, Barbara J. Milby; Belitz, Kenneth

    2012-01-01

    Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Antelope Valley is one of the study areas being evaluated. The Antelope study area is approximately 1,600 square miles (4,144 square kilometers) and includes the Antelope Valley groundwater basin (California Department of Water Resources, 2003). Antelope Valley has an arid climate and is part of the Mojave Desert. Average annual rainfall is about 6 inches (15 centimeters). The study area has internal drainage, with runoff from the surrounding mountains draining towards dry lakebeds in the lower parts of the valley. Land use in the study area is approximately 68 percent (%) natural (mostly shrubland and grassland), 24% agricultural, and 8% urban. The primary crops are pasture and hay. The largest urban areas are the cities of Palmdale and Lancaster (2010 populations of 152,000 and 156,000, respectively). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. The primary aquifers in Antelope Valley are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells in Antelope Valley are completed to depths between 360 and 700 feet (110 to 213 meters), consist of solid casing from the land surface to a depth of 180 to 350 feet (55 to 107 meters), and are screened or perforated below the solid casing. Recharge to the groundwater system is primarily runoff from the surrounding mountains, and by direct infiltration of irrigation and sewer and septic

  8. Drowsy Cheetah Hunting Antelopes: A Diffusing Predator Seeking Fleeing Prey

    OpenAIRE

    Winkler, Karen; Bray, Alan J.

    2004-01-01

    We consider a system of three random walkers (a `cheetah' surrounded by two `antelopes') diffusing in one dimension. The cheetah and the antelopes diffuse, but the antelopes experience in addition a deterministic relative drift velocity, away from the cheetah, proportional to their distance from the cheetah, such that they tend to move away from the cheetah with increasing time. Using the backward Fokker-Planck equation we calculate, as a function of their initial separations, the probability...

  9. DNA in the conservation and management of African antelope

    DEFF Research Database (Denmark)

    Lorenzen, Eline

    2016-01-01

    tool in informed species conservation and sustainable wildlife management. The movement of antelope through translocations, reintroductions, and population augmentations is common practice in wildlife management. DNA-led species identification using genetic barcoding is an effective use of genetic data...... within forensics. DNA barcoding is a taxonomic method that uses a short genetic marker in an organism's DNA to identify it as belonging to a particular species....... databases, and represents a valuable reference database of antelope DNA diversity. For the evolution of antelope, sub-Saharan Africa is a region of particular intrigue. The geographic regions of sub-Saharan Africa represent unique evolutionary scenarios. Molecular data have become an increasingly important...

  10. Water-quality variations in Antelope Creek and Deadmans Run, Lincoln, Nebraska

    Science.gov (United States)

    Pettijohn, R.A.; Engberg, R.A.

    1985-01-01

    Eleven sets of samples from five sites on Antelope Creek and Dead Man 's Run in Lincoln, Nebraska, were collected from December 1982 through June 1983 to study water-quality variations. Specific-conductance values generally were similar for Antelope Creek at 52nd Street and 27th Street, but during a low-flow survey of December 1 they increased from 974 to 8,700 microsiemens per centimeter at 25 C from 27th Street to Court Street. Seepage of saline water from underlying bedrock to the stream occurs in this reach. Specific-conductance values were less variable for Dead Man 's Run, increasing an average of only 47 percent from 66th Street to U.S. Highway 6. Specific-conductance values were less at high flows in Antelope Creek, except in samples collected on January 6, 1983, which contained runoff from salted streets. Sodium and chloride concentrations in these samples were from 5 to 10 times greater than those measured in any other samples. Stray-current corrosion occurs when current flows between dissimilar metals. Zinc-coated wire of channel-stabilization structures (gabions) may be an anode and material within the stream banks may be a cathode. Dissolution of the zinc coating by this type of corrosion may be a cause for gabion deterioration in both streams. (USGS)

  11. McClean Lake. Site Guide

    International Nuclear Information System (INIS)

    2016-09-01

    Located over 700 kilometers northeast of Saskatoon, Areva's McClean Lake site is comprised of several uranium mines and one of the most technologically advanced uranium mills in the world - the only mill designed to process high-grade uranium ore without dilution. Areva has operated several open-pit uranium mines at the McClean Lake site, and is evaluating future mines at and near the site. The McClean Lake mill has recently undergone a multimillion-dollar upgrade and expansion, which has doubled its annual production capacity of uranium concentrate to 24 million pounds. It is the only facility in the world capable of processing high-grade uranium ore without diluting it. The mill processes the ore from the Cigar Lake mine, the world's second largest and highest-grade uranium mine. The McClean Lake site operates 365 days a year on a week-in/week-out rotation schedule for workers, over 50% of whom reside in northern Saskatchewan communities. Tailings are waste products resulting from milling uranium ore. This waste is made up of leach residue solids, waste solutions and chemical precipitates that are carefully engineered for long-term disposal. The TMF serves as the repository for all resulting tailings. This facility allows proper waste management, which minimizes potential adverse environmental effects. Mining projections indicate that the McClean Lake mill will produce tailings in excess of the existing capacity of the TMF. After evaluating a number of options, Areva has decided to pursue an expansion of this facility. Areva is developing the Surface Access Borehole Resource Extraction (SABRE) mining method, which uses a high-pressure water jet placed at the bottom of the drill hole to extract ore. Areva has conducted a series of tests with this method and is evaluating its potential for future mining operations. McClean Lake maintains its certification in ISO 14001 standards for environmental management and OHSAS 18001 standards for occupational health

  12. Groundwater-flow and land-subsidence model of Antelope Valley, California

    Science.gov (United States)

    Siade, Adam J.; Nishikawa, Tracy; Rewis, Diane L.; Martin, Peter; Phillips, Steven P.

    2014-01-01

    Antelope Valley, California, is a topographically closed basin in the western part of the Mojave Desert, about 50 miles northeast of Los Angeles. The Antelope Valley groundwater basin is about 940 square miles and is separated from the northern part of Antelope Valley by faults and low-lying hills. Prior to 1972, groundwater provided more than 90 percent of the total water supply in the valley; since 1972, it has provided between 50 and 90 percent. Most groundwater pumping in the valley occurs in the Antelope Valley groundwater basin, which includes the rapidly growing cities of Lancaster and Palmdale. Groundwater-level declines of more than 270 feet in some parts of the groundwater basin have resulted in an increase in pumping lifts, reduced well efficiency, and land subsidence of more than 6 feet in some areas. Future urban growth and limits on the supply of imported water may increase reliance on groundwater.

  13. 78 FR 59840 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2013-09-30

    ...] Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management District... of plan. * * * * * (c) * * * (428) * * * (i) * * * (B) Antelope Valley Air Quality Management...) * * * (i) * * * (B) Antelope Valley Air Quality Management District. (1) Rule 431.1, ``Sulfur Content of...

  14. 78 FR 45114 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2013-07-26

    ... the California State Implementation Plan, Antelope Valley Air Quality Management District AGENCY... the Antelope Valley Air Quality Management District (AVAQMD) portion of the California State... for the South Coast Air Quality Management District (SCAQMD). The Antelope Valley Air Pollution...

  15. 131I concentrations in air, milk and antelope thyroids in southeastern Idaho

    International Nuclear Information System (INIS)

    Markham, O.D.; Halford, D.K.; Bihl, D.E.

    1980-01-01

    Iodine-131 concentrations were determined in air, milk, and antelope (Antilocapra americana) thyroids from southeastern Idaho during 1972-77. Samples were collected in the vicinity of the Idaho National Engineering Laboratory Site which has 17 operating nuclear reactors, a fuel reprocessing plant, and a nuclear waste management facility. Samples were also collected from control areas. During the study, fallout occurred from five People's Republic of China above-ground nuclear weapon detonations. All 131 I detected in air and milk samples was attributed to fallout from the Chinese nuclear tests. 131 I was detected in low-volume air samples following only one of the five detonations while 131 I was detected in milk following four of the detonations. 131 I occurred in antelope thyroids during all five of the fallout periods and following at least one atmospheric release from facilities at the Idaho National Engineering Laboratory Site. Thyroids were the most sensitive indicators of 131 I in the environment followed by milk and then air. Maximum concentrations in thyroids, milk, and air were 400, 20 and 4 times higher respectively than their respective detection limits. (author)

  16. 76 FR 38572 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2011-07-01

    ... the California State Implementation Plan, Antelope Valley Air Quality Management District AGENCY... approve revisions to the Antelope Valley Air Quality Management District (AVAQMD) portion of the... approving with the dates that they were adopted by the Antelope Valley Air Quality Management District...

  17. Lake and lake-related drainage area parameters for site investigation program

    Energy Technology Data Exchange (ETDEWEB)

    Blomqvist, P.; Brunberg, A.K. [Uppsala Univ. (Sweden). Dept. of Limnology; Brydsten, L [Umeaa Univ. (Sweden). Dept. of Ecology and Environmental Science

    2000-09-01

    In this paper, a number of parameters of importance to a preliminary determination of the ecological function of lakes are presented. The choice of parameters have been made with respect to a model for the determination of the nature conservation values of lakes which is currently being developed by the authors of this report, but is also well suited for a general description of the lake type and the functioning of the inherent ecosystem. The parameters have been divided into five groups: (1) The location of the object relative important gradients in the surrounding nature; (2) The lake catchment area and its major constituents; (3) The lake morphometry; (4) The lake ecosystem; (5) Human-induced damages to the lake ecosystem. The first two groups, principally based on the climate, hydrology, geology and vegetation of the catchment area represent parameters that can be used to establish the rarity and representativity of the lake, and will in the context of site investigation program be used as a basis for generalisation of the results. The third group, the lake morphometry parameters, are standard parameters for the outline of sampling programmes and for calculations of the physical extension of different key habitats in the system. The fourth group, the ecosystem of the lake, includes physical, chemical and biological parameters required for determination of the stratification pattern, light climate, influence from the terrestrial ecosystem of the catchment area, trophic status, distribution of key habitats, and presence of fish and rare fauna and flora in the lake. In the context of site investigation program, the parameters in these two groups will be used for budget calculations of the flow of energy and material in the system. The fifth group, finally, describes the degree on anthropogenic influence on the ecosystem and will in the context of site investigation programmes be used to judge eventual malfunctioning within the entire, or parts of, the lake

  18. Lake and lake-related drainage area parameters for site investigation program

    International Nuclear Information System (INIS)

    Blomqvist, P.; Brunberg, A.K.; Brydsten, L

    2000-09-01

    In this paper, a number of parameters of importance to a preliminary determination of the ecological function of lakes are presented. The choice of parameters have been made with respect to a model for the determination of the nature conservation values of lakes which is currently being developed by the authors of this report, but is also well suited for a general description of the lake type and the functioning of the inherent ecosystem. The parameters have been divided into five groups: 1) The location of the object relative important gradients in the surrounding nature; 2) The lake catchment area and its major constituents; 3) The lake morphometry; 4) The lake ecosystem; 5) Human-induced damages to the lake ecosystem. The first two groups, principally based on the climate, hydrology, geology and vegetation of the catchment area represent parameters that can be used to establish the rarity and representativity of the lake, and will in the context of site investigation program be used as a basis for generalisation of the results. The third group, the lake morphometry parameters, are standard parameters for the outline of sampling programmes and for calculations of the physical extension of different key habitats in the system. The fourth group, the ecosystem of the lake, includes physical, chemical and biological parameters required for determination of the stratification pattern, light climate, influence from the terrestrial ecosystem of the catchment area, trophic status, distribution of key habitats, and presence of fish and rare fauna and flora in the lake. In the context of site investigation program, the parameters in these two groups will be used for budget calculations of the flow of energy and material in the system. The fifth group, finally, describes the degree on anthropogenic influence on the ecosystem and will in the context of site investigation programmes be used to judge eventual malfunctioning within the entire, or parts of, the lake ecosystem

  19. In vivo and in vitro development of Tibetan antelope (Pantholops hodgsonii interspecific cloned embryos

    Directory of Open Access Journals (Sweden)

    Guanghua SU,Lei CHENG,Yu GAO,Kun LIU,Zhuying WEI,Chunling BAI,Fengxia YIN,Li GAO,Guangpeng LI,Shorgan BOU

    2014-02-01

    Full Text Available The Tibetan antelope is endemic to the Tibetan Plateau, China, and is now considered an endangered species. As a possible rescue strategy, the development of embryos constructed by interspecies somatic cell nuclear transfer (iSCNT was examined. Tibetan antelope fibroblast cells were transferred into enucleated bovine, ovine and caprine oocytes. These cloned embryos were then cultured in vitro or in the oviducts of intermediate animals. Less than 0.5% of the reconstructed antelope-bovine embryos cultured in vitro developed to the blastocyst stage. However, when the cloned antelope-bovine embryos were transferred to caprine oviducts, about 1.6% of the embryos developed to the blastocyst stage. In contrast, only 0.7% of the antelope-ovine embryos developed to the morula stage and none developed to blastocysts in ovine oviducts. The treatment of donor cells and bovine oocytes with trichostatin A did not improve the embryo development even when cultured in the oviducts of ovine and caprine. When the antelope-bovine embryos, constructed from oocytes treated with roscovitine or trichostatin A, were cultured in rabbit oviducts 2.3% and 14.3% developed to blastocysts, respectively. It is concluded that although some success was achieved with the protocols used, interspecies cloning of Tibetan antelope presents difficulties still to be overcome. The mechanisms resulting in the low embryo development need investigation and progress might require a deeper understanding of cellular reprogramming.

  20. Running energetics in the pronghorn antelope.

    Science.gov (United States)

    Lindstedt, S L; Hokanson, J F; Wells, D J; Swain, S D; Hoppeler, H; Navarro, V

    1991-10-24

    The pronghorn antelope (Antilocapra americana) has an alleged top speed of 100 km h-1, second only to the cheetah (Acionyx jubatus) among land vertebrates, a possible response to predation in the exposed habitat of the North American prairie. Unlike cheetahs, however, pronghorn antelope are distance runners rather than sprinters, and can run 11 km in 10 min, an average speed of 65 km h-1. We measured maximum oxygen uptake in pronghorn antelope to distinguish between two potential explanations for this ability: either they have evolved a uniquely high muscular efficiency (low cost of transport) or they can supply oxygen to the muscles at unusually high levels. Because the cost of transport (energy per unit distance covered per unit body mass) varies as a predictable function of body mass among terrestrial vertebrates, we can calculate the predicted cost to maintain speeds of 65 and 100 km h-1 in an average 32-kg animal. The resulting range of predicted values, 3.2-5.1 ml O2 kg-1 s-1, far surpasses the predicted maximum aerobic capacity of a 32-kg mammal (1.5 ml O2 kg-1 s-1). We conclude that their performance is achieved by an extraordinary capacity to consume and process enough oxygen to support a predicted running speed greater than 20 ms-1 (70 km h-1), attained without unique respiratory-system structures.

  1. Characterization of a novel pestivirus originating from a pronghorn antelope.

    Science.gov (United States)

    Vilcek, S; Ridpath, J F; Van Campen, H; Cavender, J L; Warg, J

    2005-03-01

    A unique pestivirus, isolated from a pronghorn antelope (Antilocopra americana), was characterized. Serum neutralization studies suggested that this virus was antigenically related to pestiviruses. Genomic characteristics, unique to pestiviruses, indicated that this virus belongs to the Pestivirus genus. These characteristics included the organization of the 5' untranslated region (5'-UTR), the presence and length of a viral Npro coding region, conservation of cysteine residues in Npro, conservation of predicted amino acid sequences flanking the cleavage sites between viral polypeptides Npro and C and between C and Erns and conservation of predicted hydrophobicity plots of Npro protein. While this data indicated the virus belongs to the Pestivirus genus, phylogenetic analysis in 5'-UTR, Npro and E2 regions suggested that it is the most divergent of the pestiviruses identified to date. This conclusion was also supported by the amino acid identity in coding regions. The corresponding values were much lower for the comparison of pronghorn pestivirus to other pestivirus genotypes than only between previous recognized genotypes. These results suggest the virus isolated from pronghorn antelope represents a new pestivirus genotype. It also represents the only pestivirus genotype first isolated from New World wildlife.

  2. A questionnaire survey of the management and use of anthelmintics in cattle and antelope in mixed farming systems in Zimbabwe

    Directory of Open Access Journals (Sweden)

    O. Madzingira

    2002-07-01

    Full Text Available A survey of the management of mixed farming of cattle and antelope and use of anthelmintics was conducted on eleven farms between August and December 1999 by a self-administered questionnaire. Seventeen antelope species ranging from grey duikers (Sylvicapra grimmia to eland (Taurotragus oryx occurred on the farms. Impala (Aepyceros melampus was the most abundant antelope on the farms. Seventy-five per cent of the antelope species on the farms were grazers and mixed feeders and shared grazing with cattle. Most farmers (n =8 did not consider the stocking density for cattle and antelope as an important management factor. Fifty-four per cent of the farmers (n = 6 routinely dewormed both cattle and antelopes. Albendazole and fenbendazole were the most commonly used drugs for deworming cattle (72.7 % and antelope species (54.5 %. The deworming of antelope was carried out during the dry season, using albendazole-, fenbendazole-and rafoxanide-medicated supplementary feed blocks. Doramectin injections were given to antelopes on two farms. Cattle were dewormed preventively and according to the general body condition of the animal. Few farmers (n = 4 followed the recommended deworming programme for cattle in Zimbabwe and only one farmer followed a specified dosing programme for game. However, results from the survey on the deworming of game indicate that farmers perceived helminth infections in antelope to be important.

  3. 78 FR 49925 - Revisions to California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2013-08-16

    ... California State Implementation Plan, Antelope Valley Air Quality Management District and Ventura County Air...: EPA is taking direct final action to approve revisions to the Antelope Valley Air Quality Air Management District (AVAQMD) and Ventura County Air Pollution Control District (VCAPCD) portions of the...

  4. Habitat preference of Roan Antelope (Hippotragus equinus ...

    African Journals Online (AJOL)

    Key words: Habitat Preference, Roan Antelope, Seasons. INTRODUCTION. Habitat quality and quantity have been identified as the primary limiting factors that influence animal population dynamics. (Jansen et al., 2001). Habitat influences the presence, abundance, distribution, movement and behavior of game animals.

  5. 77 FR 2469 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2012-01-18

    ... the California State Implementation Plan, Antelope Valley Air Quality Management District and Imperial... Quality Management District (AVAQMD) and Imperial County Air Pollution Control District (ICAPCD) portions... Technology (RACT),'' adopted on February 23, 2010. * * * * * (G) Antelope Valley Air Quality Management...

  6. 78 FR 58459 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2013-09-24

    ... the California State Implementation Plan, Antelope Valley Air Quality Management District, Santa Barbara County Air Pollution Control District, South Coast Air Quality Management District and Ventura.... SUMMARY: EPA is finalizing approval of revisions to the Antelope Valley Air Quality Management District...

  7. 78 FR 25011 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2013-04-29

    ... the California State Implementation Plan, Antelope Valley Air Quality Management District, Santa Barbara County Air Pollution Control District, South Coast Air Quality Management District and Ventura... rule. SUMMARY: EPA is proposing to approve revisions to the Antelope Valley Air Quality Management...

  8. 77 FR 12526 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2012-03-01

    ... the California State Implementation Plan, Antelope Valley Air Quality Management District and Mojave Desert Quality Management District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the Antelope Valley Air Quality Management District...

  9. 76 FR 38589 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2011-07-01

    ... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 [EPA-R09-OAR-2011-0383; FRL-9428-1] Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management District AGENCY... the Antelope Valley Air Quality Management District (AVAQMD) portion of the California State...

  10. 77 FR 2496 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2012-01-18

    ... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 [EPA-R09-OAR-2011-0987; FRL-9617-5] Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management District and Imperial... rule. SUMMARY: EPA is proposing to approve revisions to the Antelope Valley Air Quality Management...

  11. 78 FR 49992 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2013-08-16

    ... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 [EPA-R09-OAR-2013-0394; FRL-9845-4] Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management District and Ventura... rule. SUMMARY: EPA is proposing to approve revisions to the Antelope Valley Air Quality Management...

  12. Addendum to the Closure Report for Corrective Action Unit 484: Surface Debris, Waste Sites, and Burn Area, Tonopah Test Range, Nevada (Revision 0)

    International Nuclear Information System (INIS)

    Burmeister, Mark

    2011-01-01

    Corrective Action Unit (CAU) 484 Streamlined Approach for Environmental Restoration (SAFER) activities called for the identification and remediation of surface hot spot depleted uranium (DU) with some excavation to determine the vertical extent of contamination (NNSA/NSO, 2004). During the CAU 484 SAFER investigation (conducted November 2003 through August 2007), approximately 50 locations containing DU were identified on Antelope Lake. All but four locations (CA-1, SA-5-9, SA-12-15, and SA-4) were remediated. Figure 1-1 shows locations of the four use restriction (UR) sites. The four locations were determined to have failed the SAFER conceptual site model assumption of a small volume hot spot. Two of the locations (CA-1 and SA-5-9) were excavated to depths of 3.5 to 7 feet (ft) below ground surface (bgs), and a third location (SA-12-15) with a footprint of 30 by 60 ft was excavated to a depth of 0.5 ft. At the fourth site (SA-4), the discovery of unexploded ordnance (UXO) halted the excavation due to potential safety concerns. Remediation activities on Antelope Lake resulted in the removal of approximately 246 cubic yards (yd3) of DU-impacted soil from the four UR sites; however, Kiwi surveys confirmed that residual DU contamination remained at each of the four sites. (The Kiwi was a Remote Sensing Laboratory [RSL] vehicle equipped with a data-acquisition system and four sodium iodide gamma detectors. Surveys were conducted with the vehicle moving at a rate of approximately 10 miles per hour with the gamma detectors positioned 14 to 28 inches [in.] above the ground surface [NNSA/NSO, 2004]).

  13. Antelope Valley Community College District Education Center.

    Science.gov (United States)

    Newmyer, Joe

    An analysis is provided of a proposal to the Board of Governors of the California Community Colleges by the Antelope Valley Community College District (AVCCD) to develop an education center in Palmdale to accommodate rapid growth. First, pros and cons are discussed for the following major options: (1) increase utilization and/or expand the…

  14. The species of the Antelope-genus Pediotragus

    NARCIS (Netherlands)

    Jentink, F.A.

    1900-01-01

    A skin of a male antelope, collected by Mr. A. Sharpe in Southern Angoniland has been described by Mr. Oldfield Thomas under a new specific title, Rhaphiceros Sharpei (P. Z. S. L. 1896, p. 796, plate XXXIX); the author had no cranial evidence of its age, as the skull of the individual was wanting.

  15. Carcass and primal cuts yield evaluation of African antelope ...

    African Journals Online (AJOL)

    Iwoye, Ogun State Nigeria and were transported to the Meat Science Laboratory of the Department of Animal Production, Olabisi Onabanjo University, Yewa Campus, Ayetoro, Ogun State, where the study was conducted. The Antelopes were ...

  16. Genetic patterns in forest antelope populations in the Udzungwa Mountains, Tanzania, as inferred from non-invasive sampling

    DEFF Research Database (Denmark)

    Bowkett, Andrew E.; Jones, Trevor; Rovero, Francesco

    2015-01-01

    As for many tropical regions, the evolutionary and demographic status of antelope populations in the Udzungwa Mountains, Tanzania, are poorly resolved. We employed genetic information from 618 faecal samples to assess the status of forest antelope species in terms of their distribution, intraspec...... except the endangered C. spadix. Overall, our results demonstrate the value of non-invasive genetic sampling in studying the distribution and evolution of rarely observed species.......As for many tropical regions, the evolutionary and demographic status of antelope populations in the Udzungwa Mountains, Tanzania, are poorly resolved. We employed genetic information from 618 faecal samples to assess the status of forest antelope species in terms of their distribution......, intraspecific diversity and population subdivision within the Udzungwa landscape. Most species were detected in the majority of forest fragments, except for Philantomba monticola. Phylogenetic analyses were consistent with traditional taxonomy with the exception of Cephalophus harveyi which was paraphyletic...

  17. [Genetic cloning and expression of hypoxia inducible factor 1 alpha in high altitude hypoxic adaptation species Tibetan antelope (Pantholops hodgsonii)].

    Science.gov (United States)

    Liu, Fang; Wuren, Tana; Ma, Lan; Yang, Ying-Zhong; Ge, Ri-Li

    2011-12-25

    In order to investigate the role of the hypoxia inducible factor 1 alpha (HIF-1α) in the adaptation mechanism to high altitude hypoxia, the cloning of the HIF-1α gene cDNA of Tibetan antelope (Pantholops hodgsonii), using RT-PCR and RACE, was applied, and the comparative analysis of the tissue-specific expressions of HIF-1α among Tibetan antelope, Tibetan sheep and plain sheep was performed using real-time PCR and Western blot. The sequence analysis indicated that the cDNA sequences acquired by cloning from the HIF-1α gene of Tibetan antelope comprised a 2 471-bp open reading frame (ORF) and a 1 911-bp 3'UTR. The similarity between its coding sequence, predicted amino acid sequence and HIF-1α of other mammals exceeded 87%, in which the similarity with cow was up to more than 98%, which showed that this sequence was the cDNA of HIF-1α of Tibetan antelope. The results of real-time PCR and Western blot showed that expressions of HIF-1α mRNA and protein appeared in Tibetan antelope's lung, cardiac muscle and skeletal muscle, with the highest expression in lung. HIF-1α mRNA and protein had obvious differential expression in these tissues. Further research showed that Tibetan antelope and Tibetan sheep possessed higher expressions of HIF-1α protein in the three tissues above-mentioned compared with plain sheep, and the expressions of HIF-1α mRNA and protein in Tibetan antelope's lung, cardiac muscle and skeletal muscle were higher than those of Tibetan sheep. It illustrates that the hypoxic HIF-1α-specific expression is one of the molecular bases of high altitude hypoxia adaptation in Tibetan antelope.

  18. Site Observational Work Plan for the UMTRA project site at Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    1995-02-01

    Ground water compliance for the Uranium Mill Tailings Remedial Action (UMTRA) Project sites, including the Ambrosia Lake, New Mexico, site, is governed by the Uranium Mills Tailings Radiation Control Act (42 USC section 7901 et seq.) and the U.S. Environmental Protection Agency's Health and Environmental Protection Standards for Uranium and Thorium Mill Tailings (40 CFR Part 192; 60 FR 2854). The EPA standards describe specific conditions for which the U.S. Department of Energy (DOE) may apply for supplemental standards for contaminated ground water rather than meeting background levels or numerical standards. To achieve compliance with Subpart A of the EPA standards the residual radioactive materials are currently being consolidated on the site by the DOE in a disposal cell, isolating them from direct human or ecological contact and further dispersion into the environment. Completion of the disposal cell is scheduled for early 1995. An environmental assessment and a Finding of No Significant Impact (FONSI) were completed in 1987. Concurrence with the UMTRA Surface Project Ambrosia Lake remedial action plan (RAP) was granted by the U.S. Nuclear Regulatory Commission (NRC) and state of New Mexico in 1990. The DOE deferred compliance with Subpart B of the EPA standards in the Surface Project RAP. This site observational work plan (SOWP) is the first document to address ground water compliance under Subpart B at the Ambrosia Lake site. The Ambrosia Lake UMTRA Project site is within the Grants Mineral Belt and was one of numerous uranium mills supplied by many local mines. Ground water contamination at the site occurred as a result of uranium mill operations. Contamination of ground water resulted from discharge of waste water, infiltration of water through the tailings pile, hydraulic placement of mill tailings in nearby mines, and water pumped from mine shafts

  19. Rangeland restoration for Hirola, the world's most endangered antelope

    Science.gov (United States)

    Rangeland restoration can improve habitat for threatened species such as the hirola antelope (Beatragus hunteri) that inhabit savannas of eastern Kenya. However, restoration success likely varies across soil types and target restoration species, as well as according to restoration approach. We teste...

  20. Late Pleistocene to Holocene lake levels of Lake Warner, Oregon (USA) and their effect on archaeological site distribution patterns

    Science.gov (United States)

    Wriston, T.; Smith, G. M.

    2017-12-01

    Few chronological controls are available for the rise and fall of small pluvial lake systems in the Northwestern Great Basin. Within Warner Basin this control was necessary for interpretation of known archaeological sites and for predicting where evidence of its earliest inhabitants might be expected. We trenched along relic beach ridges of Lake Warner, surveyed a stratified sample of the area for archaeological sites, and excavated some sites and a nearby rockshelter. These efforts produced new ages that we used to construct a lake level curve for Lake Warner. We found that the lake filled the valley floor between ca. 30,000 cal yr BP and ca. 10,300 cal yr BP. In nearby basins, several oscillations are evident before ca. 21,100 cal yr BP, but a steep rise to the LGM maximum occurred between 21,000 and 20,000 cal yr BP. Lake Warner likely mirrored these changes, dropped to the valley floor ca. 18,340 cal yr BP, and then rose to its maximum highstand when its waters briefly reached 1454 m asl. After this highstand the lake receded to moderately high levels. Following ca. 14,385 cal yr BP, the lake oscillated between moderate to moderately-high levels through the Bolling-Allerod interstadials and into the Younger Dryas stadial. The basin's first occupants arrived along its shore around this time, while the lake still filled the valley floor. These earliest people carried either Western Stemmed or Clovis projectile points, both of which are found along the lake margin. The lake receded into the valley floor ca. 10,300 cal yr BP and dune development began, ringing wetlands and small lakes that persisted in the footprint of the once large lake. By the time Mazama tephra fell 7,600 cal yr BP it blanketed pre-existing dunes and marsh peats. Our Lake Warner lake level curve facilitates interdisciplinary testing and refinement of it and similar curves throughout the region while helping us understand the history of lake and the people who lived along its shores.

  1. Site observational work plan for the UMTRA Project site at Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    1994-09-01

    The Ambrosia Lake Uranium Mill Tailings Remedial Action (UMTRA) Project site is within the Grants Mineral Belt and was one of numerous uranium mills supplied by many local mines. Ground water contamination at the site occurred as a result of uranium mill operations. The potential for impacts to human health and the environment from contaminated ground water currently does not exist. No domestic or livestock wells accessing ground water from the uppermost aquifer have been identified within a 5 mile radius from the site. Therefore, no current exposure pathways to humans, livestock, or wildlife exist, nor are any foreseen. The proposed ground water compliance strategy under consideration for application at the Ambrosia Lake site is to perform no remediation, based on the application of supplemental standards because the ground water has ''limited use.''

  2. Spawning site fidelity and apparent annual survival of walleye (Sander vitreus) differ between a Lake Huron and Lake Erie tributary

    Science.gov (United States)

    Hayden, Todd A.; Binder, Thomas; Holbrook, Christopher; Vandergoot, Christopher; Fielder, David G.; Cooke, Steven J.; Dettmers, John M.; Krueger, Charles C.

    2018-01-01

    Fidelity to spawning habitats can maximise reproductive success of fish by synchronising movements to sites of previous recruitment. To determine the role of reproductive fidelity in structuring walleye Sander vitreus populations in the Laurentian Great Lakes, we used acoustic telemetry combined with Cormack–Jolly–Seber capture–recapture models to estimate spawning site fidelity and apparent annual survival for the Tittabawassee River in Lake Huron and Maumee River in Lake Erie. Walleye in spawning condition were tagged from the Tittabawassee River in Lake Huron and Maumee River in Lake Erie in 2011–2012. Site fidelity and apparent annual survival were estimated from return of individuals to the stream where tagged. Site fidelity estimates were higher in the Tittabawassee River (95%) than the Maumee River (70%) and were not related to sex or fish length at tagging. Apparent annual survival of walleye tagged in the Tittabawassee did not differ among spawning seasons but was higher for female than male walleye and decreased linearly as fish length increased. Apparent annual survival of walleye tagged in the Maumee River did not differ among spawning seasons but was higher for female walleye than male walleye and increased linearly as fish length increased. Greater fidelity of walleye tagged in the Tittabawassee River than walleye tagged in the Maumee River may be related to the close proximity to the Maumee River of other spawning aggregations and multiple spawning sites in Lake Erie. As spawning site fidelity increases, management actions to conserve population structure require an increasing focus on individual stocks.

  3. Scent marking in a territorial African antelope: I. The maintenance of borders between male oribi.

    Science.gov (United States)

    Brashares; Arcese

    1999-01-01

    Scent marking is ubiquitous among the dwarf antelope and gazelles of Africa, but its function has been the subject of debate. This study examined preorbital gland scent marking in the oribi, Ourebia ourebi, a territorial African antelope. Several hypotheses for the function of scent marking by territorial antelope were tested with observational data. Of these, the hypotheses that scent marking is driven by intrasexual competition between neighbouring males, and that marks serve as an honest advertisement of a male's ability to defend his territory from rivals, were supported best. Thirty-three territorial male oribi on 23 territories marked most at borders shared with other territorial males, and territorial males marked more often at borders shared with multimale groups than at borders shared with a single male. This suggests that males perceived neighbouring male groups as a greater threat to territory ownership than neighbouring males that defended their territories without the aid of adult subordinates. Marking rate was unrelated to territory size or the number of females on adjacent territories, but males with many male neighbours marked at higher rates than those with fewer male neighbours. These results suggest that the presence of male neighbours has a greater effect on the scent marking behaviour of territorial antelope than has been considered previously. Copyright 1999 The Association for the Study of Animal Behaviour.

  4. Tephrostratigraphy the DEEP site record, Lake Ohrid

    Science.gov (United States)

    Leicher, N.; Zanchetta, G.; Sulpizio, R.; Giaccio, B.; Wagner, B.; Francke, A.

    2016-12-01

    In the central Mediterranean region, tephrostratigraphy has been proofed to be a suitable and powerful tool for dating and correlating marine and terrestrial records. However, for the period older 200 ka, tephrostratigraphy is incomplete and restricted to some Italian continental basins (e.g. Sulmona, Acerno, Mercure), and continuous records downwind of the Italian volcanoes are rare. Lake Ohrid (Macedonia/Albania) in the eastern Mediterranean region fits this requisite and is assumed to be the oldest continuously existing lake of Europe. A continous record (DEEP) was recovered within the scope of the ICDP deep-drilling campaign SCOPSCO (Scientific Collaboration on Past Speciation Conditions in Lake Ohrid). In the uppermost 450 meters of the record, covering more than 1.2 Myrs of Italian volcanism, 54 tephra layers were identified during core-opening and description. A first tephrostratigraphic record was established for the uppermost 248 m ( 637 ka). Major element analyses (EDS/WDS) were carried out on juvenile glass fragments and 15 out of 35 tephra layers have been identified and correlated with known and dated eruptions of Italian volcanoes. Existing 40Ar/39Ar ages were re-calculated by using the same flux standard and used as first order tie points to develop a robust chronology for the DEEP site succession. Between 248 and 450 m of the DEEP site record, another 19 tephra horizons were identified and are subject of ongoing work. These deposits, once correlated with known and dated tephra, will hopefully enable dating this part of the succession, likely supported by major paleomagnetic events, such as the Brunhes-Matuyama boundary, or the Cobb-Mountain or the Jaramillo excursions. This makes the Lake Ohrid record a unique continuous, distal record of Italian volcanic activity, which is candidate to become the template for the central Mediterranean tephrostratigraphy, especially for the hitherto poorly known and explored lower Middle Pleistocene period.

  5. Challenges faced in the conservation of rare antelope: a case study on the northern basalt plains of the Kruger National Park

    Directory of Open Access Journals (Sweden)

    C.C. Grant

    2002-12-01

    Full Text Available The conservation of rare antelope has long been one of the goals of the Kruger National Park. The roan antelope Hippotragus equinus, and to a lesser extent the tsessebe Damaliscus lunatus, represent low-density species or rare antelope in the park. Specific management approaches representing the older equilibrium approach, have been employed to conserve these antelope. Of these, the supply of artificial water over many decades was the most resource intensive. The sudden, severe drop in the roan antelope population towards the end of the 1980s was unexpected and, retrospectively, attributed to the development of a high density of perennial waterpoints. The postulated mechanism was that the perennial presence of water allowed Burchell’s zebra Equus burchelli to stay permanently in an area that was previously only seasonally accessible. The combined effect of a long, dry climatic cycle, high numbers of zebra and their associated predators was proposed to be the cause of this decline. As part of the new nature evolving or ecosystem resilience approach, twelve artificial waterpoints were closed in the prime roan antelope habitat in 1994 in an attempt to move the zebra out of this area. The zebra numbers declined as the rainfall increased. Closure of waterholes clearly led to redistribution of zebra numbers on the northern plains, zebra tending to avoid areas within several kilometres of closed waterpoints. However, at a larger scale, regional densities appeared similar in areas with and without closed waterpoints. There was an initial drop in the lion numbers in 1995, after which they stabilised. In spite of an improvement in the grass species composition and an increase in biomass the roan antelope population did not increase. The complexity of maintaining a population at the edge of their distribution and the problems associated with the conservation of such populations are discussed in terms of management options and monitoring approaches that

  6. Plutonium in the lungs of pronghorn antelope near a nuclear fuel reprocessing plant

    International Nuclear Information System (INIS)

    Markham, O.D.; Dickson, R.L.; Autenrieth, R.E.

    1979-01-01

    The lungs of pronghorn antelope which are common on the Idaho National Engineering Laboratory (INEL) site were sampled as a bioindicator of plutonium in the environment near the Idaho Chemical Processing Plant which is located on the INEL site. Lungs were collected from September 1972 to December 1976 and analyzed for Pu. The source of Pu found in the lungs could be determined from a study of the 238 Pu/ 239-240 Pu ratio as there is a higher proportion of 238 Pu in the chemical plant releases than in world-wide fallout in the soils of Southeastern Idaho. Results indicate that 238 Pu from the chemical plant is being deposited in lungs and possibly other tissues of pronghorn. Only a proportion of the animals close to the plant had detectable quantities. Concentrations were near the detection limits and do not constitute a health hazard to the pronghorn. Meaningful comparisons can be made to radiation protection standards since pronghorn lungs are similar in size to man's. (author)

  7. Antelope--Fossil rebuild project

    International Nuclear Information System (INIS)

    1992-04-01

    The Columbia Power Cooperative Association (CPCA), Monument, Oregon, proposes to upgrade a 69-kV transmission line in Wasco and Wheeler Counties, Oregon, between the Antelope Substation and the Bonneville Power Administration's (BPA) Fossil Substation. The project involves rebuilding and reconductoring 23.2 miles of transmission line, including modifying it for future use at 115 kV. Related project activities will include setting new wood pole structures, removing and disposing of old structures, conductors, and insulators, and stringing new conductor, all within the existing right-of-way. No new access roads will be required. A Borrower's Environmental Report was prepared for the 1992--1993 Work Plan for Columbia Power Cooperative Association in March 1991. This report investigated cultural resources, threatened or endangered species, wetlands, and floodplains, and other environmental issues, and included correspondence with appropriate Federal, state, and local agencies. The report was submitted to the Rural Electrification Administration for their use in preparing their environmental documentation for the project

  8. Intracytoplasmic Crystalline Inclusions in the Hepatocytes of an Antelope

    Science.gov (United States)

    2010-01-01

    trout [7]. They have never been described in antelopes. The current report describes the his- tological and electron microscopic features of...red O (Figure 2(b)), glycogen with periodic acid-Schiff stain (with and without diastase digestion ) (Figure 2(d)), and acid mucopolysaccharides. The...female Ohrid trout (Salmo letnica Kar.),” Tissue and Cell, vol. 41, no. 4, pp. 281–285, 2009. [8] G. S. Murti and R. Borgmann, “Intracytoplasmic periodic

  9. Book review: Bovids of the World: Antelopes, gazelles, cattle, goats, sheep, and relatives

    Science.gov (United States)

    Leslie, David

    2017-01-01

    No abstract available.Book info: Bovids of the World: Antelopes, Gazelles, Cattle, Goats, Sheep, and Relatives. José R. Castelló. 2016. Princeton University Press, Princeton, New Jersey, USA. 664 pp. ISBN 978-0-691-16717-6.

  10. Microchip transponder thermometry for monitoring core body temperature of antelope during capture.

    Science.gov (United States)

    Rey, Benjamin; Fuller, Andrea; Hetem, Robyn S; Lease, Hilary M; Mitchell, Duncan; Meyer, Leith C R

    2016-01-01

    Hyperthermia is described as the major cause of morbidity and mortality associated with capture, immobilization and restraint of wild animals. Therefore, accurately determining the core body temperature of wild animals during capture is crucial for monitoring hyperthermia and the efficacy of cooling procedures. We investigated if microchip thermometry can accurately reflect core body temperature changes during capture and cooling interventions in the springbok (Antidorcas marsupialis), a medium-sized antelope. Subcutaneous temperature measured with a temperature-sensitive microchip was a weak predictor of core body temperature measured by temperature-sensitive data loggers in the abdominal cavity (R(2)=0.32, bias >2 °C). Temperature-sensitive microchips in the gluteus muscle, however, provided an accurate estimate of core body temperature (R(2)=0.76, bias=0.012 °C). Microchips inserted into muscle therefore provide a convenient and accurate method to measure body temperature continuously in captured antelope, allowing detection of hyperthermia and the efficacy of cooling procedures. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. California; Antelope Valley Air Quality Management District; VOCs from Motor Vehicle Assembly Coating Operations

    Science.gov (United States)

    EPA is proposing to approve a revision to the Antelope Valley Air Quality Management District portion of the California SIP concerning emissions of volatile organic compounds (VOCs) from motor vehicle assembly coating operations.

  12. The Cottonwood Lake study area, a long-term wetland ecosystem monitoring site

    Science.gov (United States)

    Mushet, David M.; Euliss, Ned H.

    2012-01-01

    The Cottonwood Lake study area is one of only three long-term wetland ecosystem monitoring sites in the prairie pothole region of North America; the other two are Orchid Meadows in South Dakota and St. Denis in Saskatchewan. Of the three, Cottonwood Lake has, by far, the longest continuous data-collection record. Research was initiated at the study area in 1966, and intensive investigations of the hydrology, chemistry, and biology of prairie pothole wetlands continue at the site today. This fact sheet describes the study area, provides an overview of wetland ecology research that has been conducted at the site in the past, and provides an introduction to current work being conducted at the study area by USGS scientists.

  13. A note on the behaviour of Four-horned Antelope Tetracerus quadricornis de Blainville, 1816 (Mammalia: Cetartiodactyla: Bovidae in lowland Nepal

    Directory of Open Access Journals (Sweden)

    Krishna Prasad Pokharel

    2015-05-01

    Full Text Available Behavioural studies provide the reasons behind habitat preferences of animals and their fitness to survive and propagate.  The Four-horned Antelope, an endangered endemic species to the Indian subcontinent was monitored at Ratamate area of Babai Valley in Bardia National Park, Nepal.  We used ad libitum sampling and focal animal sampling within the rule for continuous recording of ‘all-occurrences’ of ‘vigilance’ behaviour. We found that the Four-horned Antelope remains ‘alert and vigilant’ during 40% of its behavioural time budget when it scans the surroundings with raised head, with or without chewing. In the event of sudden threat it ‘freezes’, lying down still and hiding in the ground cover.  Therefore, maintenance of ground cover should form a regular practice in conservation management of the Four-horned Antelope

  14. Wildlife mitigation and monitoring report Gunnison, Colorado, site

    International Nuclear Information System (INIS)

    1997-04-01

    The Uranium Mill Tailings Remedial Action (UMTRA) Project is administered by the U.S. Department of Energy (DOE); its purpose is to cleanup uranium mill tailings and other contaminated material at 24 UMTRA Project sites in 10 states. This report summarizes the wildlife mitigation and monitoring program under way at the Gunnison UMTRA Project, Gunnison, Colorado. Remedial action at the Gunnison site was completed in December 1995 and is described in detail in the Gunnison completion report. The impacts of this activity were analyzed in the Gunnison environmental assessment (EA). These impacts included two important game species: the pronghorn antelope (Antilocapra americans) and sage grouse (Wentrocerus urophasianus). Haul truck traffic was predicted to limit antelope access to water sources north of the Tenderfoot Mountain haul road and that truck traffic along this and other haul roads could result in antelope road kills. Clearing land at the disposal cell, haul road and borrow site activities, and the associated human activities also were predicted to negatively impact (directly and indirectly) sage grouse breeding, nesting, loafing, and wintering habitat. As a result, an extensive mitigation and monitoring plan began in 1992. Most of the monitoring studies are complete and the results of these studies, written by different authors, appear in numerous reports. This report will: (1) Analyze existing impacts and compare them to predicted impacts. (2) Summarize mitigation measures. (3) Summarize all existing monitoring data in one report. (4) Analyze the effectiveness of the mitigation measures

  15. Towards an adaptive management approach for the conservation of rare antelope in the Kruger National Park - outcome of a workshop held in May 2000

    Directory of Open Access Journals (Sweden)

    C.C. Grant

    2000-07-01

    Full Text Available A precipitous drop in rare antelope numbers specifically roan (Hippotragus equinis sable (Hippotragus niger and tsessebe (Damaliscus lunatus since 1986 has become one of the main concerns of management. The zebra (Equus burchelli population in the preferred habitats of these species had increased with the development of artificial waterpoints especially in the areas occupied by roan and tsessebe, and these events are hypothesised to be the main cause of the decline. Closure of artificial waterpoints resulted in moving the high-density, water-dependent zebra from the northern basalt plains, the preferred roan habitat. However, the expected responding increase in the rare antelope populations did not materialise. This lack of response over six years necessitated a critical re-evaluation of the management of rare antelope in the Kruger National Park. Subsequently, a workshop was held at Skukuza during May 2000. The options for adaptive management of the declining rare antelope populations, which was discussed at the workshop, is the subject of this manuscript. The participants felt that the removal/closure of artificial waterpoints was the most unintrusive management tool available to move high density grazers from the habitats preferred by rare antelope. Waterpoints to be closed should be carefully evaluated, and time allowed for rare antelope to respond to habitat changes. Boosting populations of roan and tsessebe by supplementing animals was seriously considered, with the proviso that it should be done under favourable circumstances. Small patch fires that could provide green grazing over extended periods were recommended. Predator control was discussed but could not obtain general support as a viable option in the Kruger National Park.

  16. A coupled regolith-lake development model applied to the Forsmark site

    Energy Technology Data Exchange (ETDEWEB)

    Brydsten, Lars; Stroemgren, Maarten (Umeaa Univ., Umeaa (Sweden))

    2010-11-15

    The Quaternary geology at the Forsmark site has been characterized using both a map of Quaternary deposits and a regolith depth model (RDM) that show the stratigraphy and thickness of different deposits. Regolith refers to all the unconsolidated deposits overlying the bedrock. The surface geology and regolith depth are important parameters for hydrogeological and geochemical modelling and for the overall understanding of the area. The safety assessment analysis should focus on processes involved during a period of 120,000 years, which includes a full glacial cycle; however, the investigations within the site description model do not cover the temporal change of the regolith, a limitation that does not fulfil the requirements for the safety assessment. To this end, this study constructs a model that can predict the surface geology, stratigraphy, and thickness of different strata at any time during a glacial cycle and applies this model to the Forsmark site. The Weichselian ice sheet covered the study area until around 9500 BC. The deglaciation revealed a marine landscape with bedrock, till and glacial clay. For the safety assessment, the most important unconsolidated strata are clay or silt: these small grains can bind nuclear elements more easily than coarser sediment particles. Thick layers of clay can be found where post-glacial clay settled on top of glacial clay, especially where the middle-aged erosion of postglacial clay is missing and where there is an uninterrupted sequence of accumulation of finegrained particles. Such areas could be found in deep marine basins that later become lakes when raised into a supra-marine position. The coupled regolith-lake development model (RLDM) predicts the course of events described above during an interglacial, especially the dynamics of the clay and silt particles. The RLDM is divided into two modules: a marine module that predicts the sediment dynamics caused by wind waves and a lake module that predicts the lake infill

  17. A coupled regolith-lake development model applied to the Forsmark site

    International Nuclear Information System (INIS)

    Brydsten, Lars; Stroemgren, Maarten

    2010-11-01

    The Quaternary geology at the Forsmark site has been characterized using both a map of Quaternary deposits and a regolith depth model (RDM) that show the stratigraphy and thickness of different deposits. Regolith refers to all the unconsolidated deposits overlying the bedrock. The surface geology and regolith depth are important parameters for hydrogeological and geochemical modelling and for the overall understanding of the area. The safety assessment analysis should focus on processes involved during a period of 120,000 years, which includes a full glacial cycle; however, the investigations within the site description model do not cover the temporal change of the regolith, a limitation that does not fulfil the requirements for the safety assessment. To this end, this study constructs a model that can predict the surface geology, stratigraphy, and thickness of different strata at any time during a glacial cycle and applies this model to the Forsmark site. The Weichselian ice sheet covered the study area until around 9500 BC. The deglaciation revealed a marine landscape with bedrock, till and glacial clay. For the safety assessment, the most important unconsolidated strata are clay or silt: these small grains can bind nuclear elements more easily than coarser sediment particles. Thick layers of clay can be found where post-glacial clay settled on top of glacial clay, especially where the middle-aged erosion of postglacial clay is missing and where there is an uninterrupted sequence of accumulation of finegrained particles. Such areas could be found in deep marine basins that later become lakes when raised into a supra-marine position. The coupled regolith-lake development model (RLDM) predicts the course of events described above during an interglacial, especially the dynamics of the clay and silt particles. The RLDM is divided into two modules: a marine module that predicts the sediment dynamics caused by wind waves and a lake module that predicts the lake infill

  18. An evaluation of the chemical, radiological, and ecological conditions of West Lake on the Hanford site

    Energy Technology Data Exchange (ETDEWEB)

    Poston, T.M.; Price, K.L.; Newcomer, D.R.

    1991-03-01

    West Lake and its immediate surrounding basin represent a unique habitat that is dominated by highly saline water and soil. The basin offers a valuable research site for studies of a rare and complex wetland area in the desert. This report is an evaluation of the chemical, radiological, and ecological conditions at West Lake and describes how ground water influences site properties. The scope of this evaluation consisted of a sampling program in 1989 and a review of data from the perspective of assessing the impact of Hanford Site operations on the physical, chemical, and ecological conditions of West Lake and its surrounding basin. The water level in West Lake fluctuates in relation to changes in the water table. The connection between West Lake and ground water is also supported by the presence of {sup 3}H and {sup 99}Tc in the ground water and in the lake. There are relatively high concentrations of uranium in West Lake; the highest concentrations are found in the northernmost isolated pool. Analyses of water, sediment, vegetation, and soil indicate possible shifts of isotropic ratios that indicate a reduction of {sup 235}U. Uranium-236 was not detected in West Lake water; its presence would indicate neutron-activated {sup 235}U from fuel reprocessing at Hanford. Trace metals are found at elevated concentrations in West Lake. Arsenic, chromium, copper, and zinc were found at levels in excess of US Environmental Protection Agency water quality criteria. Levels of radiological and chemical contamination in the West Lake basin are relatively low. Concentrations of fission isotopes exceed those that could be explained by atmospheric fallout, but fall short of action levels for active waste management areas. 31 refs., 8 figs., 18 tabs.

  19. An evaluation of the chemical, radiological, and ecological conditions of West Lake on the Hanford site

    International Nuclear Information System (INIS)

    Poston, T.M.; Price, K.L.; Newcomer, D.R.

    1991-03-01

    West Lake and its immediate surrounding basin represent a unique habitat that is dominated by highly saline water and soil. The basin offers a valuable research site for studies of a rare and complex wetland area in the desert. This report is an evaluation of the chemical, radiological, and ecological conditions at West Lake and describes how ground water influences site properties. The scope of this evaluation consisted of a sampling program in 1989 and a review of data from the perspective of assessing the impact of Hanford Site operations on the physical, chemical, and ecological conditions of West Lake and its surrounding basin. The water level in West Lake fluctuates in relation to changes in the water table. The connection between West Lake and ground water is also supported by the presence of 3 H and 99 Tc in the ground water and in the lake. There are relatively high concentrations of uranium in West Lake; the highest concentrations are found in the northernmost isolated pool. Analyses of water, sediment, vegetation, and soil indicate possible shifts of isotropic ratios that indicate a reduction of 235 U. Uranium-236 was not detected in West Lake water; its presence would indicate neutron-activated 235 U from fuel reprocessing at Hanford. Trace metals are found at elevated concentrations in West Lake. Arsenic, chromium, copper, and zinc were found at levels in excess of US Environmental Protection Agency water quality criteria. Levels of radiological and chemical contamination in the West Lake basin are relatively low. Concentrations of fission isotopes exceed those that could be explained by atmospheric fallout, but fall short of action levels for active waste management areas. 31 refs., 8 figs., 18 tabs

  20. Natural attenuation of trichloroethene and its degradation products at a lake-shore site

    International Nuclear Information System (INIS)

    An, Youn-Joo; Kampbell, Donald H.; Weaver, James W.; Wilson, John T.; Jeong, Seung-Woo

    2004-01-01

    Subsurface contamination by trichloroethene (TCE) was detected at a Michigan National Priorities List (NPL) site in 1982. The TCE plume resulted from the disposal of spent solvent and other chemicals at an industrial facility located in the eastern shore of Lake Michigan. TCE degradation products of three dichloroethene (DCE) isomers, vinyl chloride (VC) and ethene were present. The plume was depleted of oxygen and methanogenic at certain depths. Transects of the plume were sampled by slotted auger borings the year after the TCE plume was first discovered. Water samples were also taken from lake sediments to a depth of 12 m about 100 m offshore. Later samples were taken along the shoreline of the lake with a hand-driven probe. Later in 1998 water was taken from sediments about 3-m from the shoreline. The average concentration of each chemical and net apparent base coefficient between appropriate pairs of transects between the lower site and lakeshore were calculated. Loss rates were then calculated from an analytical solution of the two-dimensional advective-dispersive-reactive transport equation. Net apparent rate coefficients and a set of coupled reaction rate equations were used to extract the apparent loss coefficients. This study showed the field evidence for natural attenuation of TCE. - Field investigation of TCE contamination at a lake-shore site indicates that TCE is anaerobically degrading under ambient conditions

  1. Final audit report of remedial action construction at the UMTRA Project Ambrosia Lake, New Mexico, site

    International Nuclear Information System (INIS)

    1995-09-01

    The final audit report for remedial action at the Ambrosia Lake, New Mexico, Uranium Mill Tailings Remedial Action (UMTRA) Project site consists of a summary of the radiological surveillances/audits, quality assurance (QA) in-process surveillances, and a QA final closeout inspection performed by the US Department of Energy (DOE) and the Technical Assistance Contractor (TAC). One radiological surveillance and three radiological audits were performed at the Ambrosia Lake site. The surveillance was performed on 12--16 April 1993 (DOE, 1993d). The audits were performed on 26--29 July 1993 (DOE, 1993b); 21--23 March 1994 (DOE, 1994d); and 1--2 August 1994 (DOE, 1994d). The surveillance and audits resulted in 47 observations. Twelve of the observations raised DOE concerns that were resolved on site or through subsequent corrective action. All outstanding issues were satisfactorily closed out on 28 December 1994. The radiological surveillance and audits are discussed in this report. A total of seven QA in-process surveillances were performed at the Ambrosia Lake UMTRA site are discussed. The DOE/TAC Ambrosia Lake final remedial action close-out inspection was conducted on 26 July 1995 (DOE, 1995a). To summarize, a total of 155 observations were noted during DOE/TAC audit and surveillance activities. Follow-up to responses required from the RAC for the DOE/TAC surveillance and audit observations indicated that all issues related to the Ambrosia Lake site were resolved and closed to the satisfaction of the DOE

  2. Environmental Assessment of remedial action at the Ambrosia Lake uranium mill tailings site, Ambrosia Lake, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    1987-06-01

    This document assesses and compares the environmental impacts of various alternatives for remedial action at the Ambrosia Lake uranium mill tailings site located near Ambrosia Lake, New Mexico. The designated site covers 196 acres and contains 111 acres of tailings and some of the original mill structures. The Uranium Mill Tailings Radiation Control Act (UMTRCA), Public Law 95-604, authorizes the US Department of Energy to clean up the site to reduce the potential health impacts associated with the residual radioactive materials remaining at the site and at associated properties off the site. The US Environmental Protection Agency promulgated standards for th remedial action (40 CFR Part 192). Remedial action must be performed in accordance with these standards and with the concurrence of the Nuclear Regulatory Commission. The proposed action is to stabilize the tailings at their present location by consolidating the tailings and associated contaminated materials into a recontoured pile. A radon barrier would be constructed over the pile and various erosion protection measures would be taken to assure the long-term stability of the pile. Another alternative which would involve moving the tailings to a new location is also assessed in this document. This alternative would generally involve greater short-term impacts and costs but would result in stabilization of the tailings at an undeveloped location. The no action alternative is also assessed in this document.

  3. Environmental Assessment of remedial action at the Ambrosia Lake uranium mill tailings site, Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    1987-06-01

    This document assesses and compares the environmental impacts of various alternatives for remedial action at the Ambrosia Lake uranium mill tailings site located near Ambrosia Lake, New Mexico. The designated site covers 196 acres and contains 111 acres of tailings and some of the original mill structures. The Uranium Mill Tailings Radiation Control Act (UMTRCA), Public Law 95-604, authorizes the US Department of Energy to clean up the site to reduce the potential health impacts associated with the residual radioactive materials remaining at the site and at associated properties off the site. The US Environmental Protection Agency promulgated standards for th remedial action (40 CFR Part 192). Remedial action must be performed in accordance with these standards and with the concurrence of the Nuclear Regulatory Commission. The proposed action is to stabilize the tailings at their present location by consolidating the tailings and associated contaminated materials into a recontoured pile. A radon barrier would be constructed over the pile and various erosion protection measures would be taken to assure the long-term stability of the pile. Another alternative which would involve moving the tailings to a new location is also assessed in this document. This alternative would generally involve greater short-term impacts and costs but would result in stabilization of the tailings at an undeveloped location. The no action alternative is also assessed in this document

  4. Environmental assessment of remedial action at the Gunnison Uranium Mill Tailings Site near Gunnison, Colorado

    International Nuclear Information System (INIS)

    1992-02-01

    The presence of contaminated uranium mill tailings adjacent to the city of Gunnison has been a local concern for many years. The following issues were identified during public meetings that were held by the DOE prior to distribution of an earlier version of this EA. Many of these issues will require mitigation. Groundwater contamination; in December 1989, a herd of 105 antelope were introduced in an area that includes the Landfill disposal site. There is concern that remedial action-related traffic in the area would result in antelope mortality. The proposed Tenderfoot Mountain haul road may restrict antelope access to their water supply; a second wildlife issue concerns the potential reduction in sage grouse use of breeding grounds (leks) and nesting habitat; the proposed Tenderfoot Mountain haul road would cross areas designated as wetlands by US Army Corps of Engineers (COE); the proposed disposal site is currently used for grazing by cattle six weeks a year in the spring. Additional concerns were stated in comments on a previous version of this EA. The proposed action is to consolidate and remove all contaminated materials associated with the Gunnison processing site to the Landfill disposal site six air miles east of Gunnison. All structures on the site (e.g., water tower, office buildings) were demolished in 1991. The debris is being stored on the site until it can be incorporated into the disposal cell at the disposal site. All contaminated materials would be trucked to the Landfill disposal site on a to-be-constructed haul road that crosses BLM-administered land

  5. Diet of the Four-horned Antelope Tetracerus quadricornis (De Blainville, 1816 in the Churia Hills of Nepal

    Directory of Open Access Journals (Sweden)

    Amar Kunwar

    2016-05-01

    Full Text Available The food composition of the Four-horned Antelope Tetracerus quadricornis was studied in the Churia Hills of Nepal during summer, monsoon and the winter seasons of 2012–2013.  Microhistological technique was used to determine the diet.  The Four-horned Antelope was found to be a mixed feeder feeding on trees, shrubs, forbs, grasses and climbers.  Trees and shrubs contribute the major percentage of diet in all the three seasons.  The Gramineae family is consumed in highest proportion.  Mitragyna parvifolia, Bridelia retusa, Bambusa vulgaris, Hymenodictyon sp. and Ziziphus mauritiana are major tree species while Barleria cristata, Pogostemon benghalensis, Achyranthes sp., Clerodendrum viscosum are among shrubs.  Ageratum conyzoides and Blumea virens are the main forbs Eulaliopsis binata and Imperata cylindrica are the principal grass species.  Climber Trachelospermum lucidum is consumed in a small proportion.  Grasses in monsoon were consumed distinctly at a higher percentage than during the other two seasons.  The Four-horned Antelopes are concentrated feeders and browsers with a generalized feeding strategy. Similar studies need to be conducted in other landscapes and with sympatric and potential competitor species to understand its niche overlaps and degree of competition. 

  6. 77 FR 12495 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2012-03-01

    ... the California State Implementation Plan, Antelope Valley Air Quality Management District and Mojave Desert Quality Management District AGENCY: Environmental Protection Agency (EPA). ACTION: Direct final... Quality Management District (AVAQMD) and Mojave Desert Air Quality Management District (MDAQMD) portion of...

  7. Environmental assessment of remedial action at the Gunnison Uranium Mill Tailings Site near Gunnison, Colorado. Final

    Energy Technology Data Exchange (ETDEWEB)

    1992-02-01

    The presence of contaminated uranium mill tailings adjacent to the city of Gunnison has been a local concern for many years. The following issues were identified during public meetings that were held by the DOE prior to distribution of an earlier version of this EA. Many of these issues will require mitigation. Groundwater contamination; in December 1989, a herd of 105 antelope were introduced in an area that includes the Landfill disposal site. There is concern that remedial action-related traffic in the area would result in antelope mortality. The proposed Tenderfoot Mountain haul road may restrict antelope access to their water supply; a second wildlife issue concerns the potential reduction in sage grouse use of breeding grounds (leks) and nesting habitat; the proposed Tenderfoot Mountain haul road would cross areas designated as wetlands by US Army Corps of Engineers (COE); the proposed disposal site is currently used for grazing by cattle six weeks a year in the spring. Additional concerns were stated in comments on a previous version of this EA. The proposed action is to consolidate and remove all contaminated materials associated with the Gunnison processing site to the Landfill disposal site six air miles east of Gunnison. All structures on the site (e.g., water tower, office buildings) were demolished in 1991. The debris is being stored on the site until it can be incorporated into the disposal cell at the disposal site. All contaminated materials would be trucked to the Landfill disposal site on a to-be-constructed haul road that crosses BLM-administered land.

  8. Antelope bitterbrush reestablishment: a case study of plant size and browse protection effects.

    Science.gov (United States)

    G. Randy Johnson; Joel P. Okula

    2006-01-01

    After an intense stand-replacement fire in south-central Oregon, 1-y-old (1+0) bareroot seedlings of antelope bitterbrush (Purshia tridentata (Pursh) DC. [Rosaceae]) were outplanted over a 4-y period. Paired-plots were established to examine the benefits of protecting the plants from damage due to animal browsing with Vexar mesh tubing. In the first...

  9. Supplement to the site observational work plan for the UMTRA project site at Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    1995-11-01

    The purpose of this document is to provide additional and more detailed information to supplement review of the site observational work plan (SOWP) (DOE, 1995) for the Ambrosia Lake, New Mexico, Uranium Mill Tailings Remedial Action (UMTRA) Project site. This document includes a discussion of the average linear velocity of the ground water in the alluvium and a discussion of the ground water quality of the alluvium, weathered Mancos Shale, and the Tres Hermanos-C Member of the Mancos Shale. The data from a 1989 aquifer test were analyzed using the curve-matching software AQTESOLV and then compared with the original results. A hydrograph of the ground water elevations in monitoring wells screened in the alluvium is presented to show how the ground water elevations change with time. Stiff and Piper diagrams were created to describe the changes in ground water geochemistry in the alluvium/weathered Mancos Sahel unit, the Tres Hermanos-C Sandstone unit, the Tres Hermanos-B Sandstone unit, and the Dakota Sandstone. Background information on other related topics such as site history, cell construction, soil characteristics, and well construction are presented in the SOWP. A geologic cross section depicts the conceptual model of the hydrostratigraphy and ground water chemistry of the Ambrosia Lake site. Hydrogeologic information of each hydrostratigraphic unit is presented

  10. Role and movement of nilgai antelope, Boselaphus tragocamelus, in the epizootiology of cattle fever ticks (Acari: Ixodidae) in re-infestations along the Texas/Mexico border in south Texas

    Science.gov (United States)

    Nilgai antelope are the largest Asian antelope and are originally endemic to the Indian subcontinent. Nilgai were introduced into Texas in the 1940s for hunting purposes and are now the most abundant free-ranging ungulate in south Texas with population estimates in the early 1990s of more than 36,0...

  11. Preliminary hydrogeologic assessment near the boundary of the Antelope Valley and El Mirage Valley groundwater basins, California

    Science.gov (United States)

    Stamos, Christina L.; Christensen, Allen H.; Langenheim, Victoria

    2017-07-19

    The increasing demands on groundwater for water supply in desert areas in California and the western United States have resulted in the need to better understand groundwater sources, availability, and sustainability. This is true for a 650-square-mile area that encompasses the Antelope Valley, El Mirage Valley, and Upper Mojave River Valley groundwater basins, about 50 miles northeast of Los Angeles, California, in the western part of the Mojave Desert. These basins have been adjudicated to ensure that groundwater rights are allocated according to legal judgments. In an effort to assess if the boundary between the Antelope Valley and El Mirage Valley groundwater basins could be better defined, the U.S. Geological Survey began a cooperative study in 2014 with the Mojave Water Agency to better understand the hydrogeology in the area and investigate potential controls on groundwater flow and availability, including basement topography.Recharge is sporadic and primarily from small ephemeral washes and streams that originate in the San Gabriel Mountains to the south; estimates range from about 400 to 1,940 acre-feet per year. Lateral underflow from adjacent basins has been considered minor in previous studies; underflow from the Antelope Valley to the El Mirage Valley groundwater basin has been estimated to be between 100 and 1,900 acre-feet per year. Groundwater discharge is primarily from pumping, mostly by municipal supply wells. Between October 2013 and September 2014, the municipal pumpage in the Antelope Valley and El Mirage Valley groundwater basins was reported to be about 800 and 2,080 acre-feet, respectively.This study was motivated by the results from a previously completed regional gravity study, which suggested a northeast-trending subsurface basement ridge and saddle approximately 3.5 miles west of the boundary between the Antelope Valley and El Mirage Valley groundwater basins that might influence groundwater flow. To better define potential basement

  12. New approaches to dust mitigation in the Antelope Valley

    Energy Technology Data Exchange (ETDEWEB)

    Farber, R.J.; Kim, B.M.; Grantz, D.A.; Vaughn, D.L.; Zink, T.; Skadberg, K.; Cowherd, C.; Grelinger, M.A.; Campbell, R.; De Salvio, A.; VanCuren, T.; Bort, J.

    1999-07-01

    The arid deserts of the southwestern US experience a frequent dust problem which can lead to PM10 violations. Blowing dust is also one of the major air quality problems of the arid deserts. From 1992 through the present, a group of research scientists have been investigating new techniques for mitigating the windblown dust in the Mojave Desert and more specifically the Antelope Valley near Palmdale and Lancaster, CA. This paper summarizes the progress made toward dust suppression in the Antelope Valley during the initial research phase from 1992 through 1996. During this period, there were both successes and failures. Stabilizing disturbed desert lands in a water-starved environment is challenging. The initial attempts focused on revegetation of native plants by seedings. There were mixed results depending on both the magnitude and timing of the rainfall. Various types of windfences were also erected and their effectiveness was studied using BSNE's. In the present program, the objectives have been broadened to include mitigating dust from all types of disturbed lands, not only abandoned farmlands. Techniques include new approaches to revegetation using seedlings, varying water treatments and soil amendments. An array of chemical suppressants are also being evaluated for cost-effectiveness as a function of longevity. Various geometries of wind fences have also been erected in blow sand areas and are being evaluated for cost-effectiveness using an interesting evaluation scheme. This portion of the paper provides a progress report of these latest dust mitigation techniques. This current research program is due to conclude about 2002. The end product of this decade research program will be a cookbook of dust mitigation solutions for various users including regulatory agencies, the USDA NRCS, farmers and construction interests.

  13. Seismic investigations of ancient Lake Ohrid (Macedonia/Albania): a pre-site survey for the SCOPSCO ICDP-drilling campaign

    Science.gov (United States)

    Lindhorst, K.; Krastel, S.; Schwenk, T.; Kurschat, S.; Daut, G.; Wessel, M.; Wagner, B.

    2009-04-01

    Lake Ohrid (Macedonia/Albania) is probably the oldest lake in Europe (2-5 Ma), and has been found as an important archive to study the sedimentary evolution of a graben system over several million years. Lake Ohrid has a length of 30 km (N-S) and a width of 15 km (W-E) and covers an area of 360 sqkm. Two major mountain chains surround the lake, on the west side the Mocra Mountains (app. 1500 m) and on the east side the Galicica Mountain (app. 2250 m). With more than 210 endemic species described, the lake is a unique aquatic ecosystem that is of worldwide importance. An international group of scientists has recently submitted a full drilling proposal entitled SCOPSCO (Scientific Collaboration On Past Speciation Conditions in Lake Ohrid) to ICDP in order to (i) to obtain more precise information about the age and origin of the lake, (ii) to unravel the seismotectonic history of the lake area including effects of major earthquakes and associated mass wasting events, (iii) to obtain a continuous record containing information on volcanic activities and climate changes in the central northern Mediterranean region, and (iv) to better understand the impact of major geological/environmental events on general evolutionary patterns and shaping an extraordinary degree of endemic biodiversity as a matter of global significance. The lake was the target of several geophysical pre-site surveys starting with a first shallow seismic campaign in spring 2004 using a high resolution parametric sediment echosounder (INNOMAR SES-96 light). Airgun multichannel seismic data were collected during two surveys in 2007 and 2008, resulting in a dense grid of seismic lines over the entire lake. In total 650 km of shallow seismic lines 400 km of airgun multichannel seismics demonstrates the potential of Lake Ohrid as target for ICDP. Seismic profiles show that the lake can be divided into slope areas and a large central basin. The slope areas are characterized by a dense net of faults

  14. Chemical characteristics of surface waters in the Forsmark area. Evaluation of data from lakes, streams and coastal sites

    International Nuclear Information System (INIS)

    Sonesten, Lars

    2005-06-01

    This report is an evaluation of the chemical composition of surface water in lakes, streams, and at coastal sampling sites in the Forsmark area. The aim with this study is to characterise the surface water systems in the area, and the further aim with this characterisation is to be used as input material to the safety analyses and environmental impact assessments for the potential deep repository of used nuclear fuels. The data used consist of water chemical composition of lakes, streams and coastal sites from the period March 2002 - April 2004. The sampling has been performed predominantly on a monthly basis. The emphasis of the assessment has been on surface waters (0.5 m), as the water depth at all sampling locations is limited, and thereby the water systems are rarely stratified for prolonged periods. The characterisations have been restricted to the most commonly measured chemical parameters.The assessment has been divided into three parts: Comparisons within and between the lakes, streams, and coastal sites, respectively; Temporal and spatial variation, predominantly within lakes and stream sites; and Relationships between the various chemical parameters. Beside comparisons between the sampling sites within the Forsmark area, comparisons have also been made with regional and national data from the latest Swedish National Survey (2000). The analyses of temporal and spatial variation have been concentrated on the freshwater systems in the Norra Bassaengen catchment area. This catchment area is the most comprehensively investigated, and it also includes the Bolundsfjaerden sub-catchment, which is the area where the continued site investigations will be concentrated. The relationships among the sampling sites, the catchment areas, as well as the chemical parameters investigated, were examined by applying PCA analyses on the lake and stream data. In general, the freshwater systems in the Forsmark area are characterised by small and shallow oligotrophic hardwater

  15. Chemical characteristics of surface waters in the Forsmark area. Evaluation of data from lakes, streams and coastal sites

    Energy Technology Data Exchange (ETDEWEB)

    Sonesten, Lars [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Environmental Assessment

    2005-06-01

    This report is an evaluation of the chemical composition of surface water in lakes, streams, and at coastal sampling sites in the Forsmark area. The aim with this study is to characterise the surface water systems in the area, and the further aim with this characterisation is to be used as input material to the safety analyses and environmental impact assessments for the potential deep repository of used nuclear fuels. The data used consist of water chemical composition of lakes, streams and coastal sites from the period March 2002 - April 2004. The sampling has been performed predominantly on a monthly basis. The emphasis of the assessment has been on surface waters (0.5 m), as the water depth at all sampling locations is limited, and thereby the water systems are rarely stratified for prolonged periods. The characterisations have been restricted to the most commonly measured chemical parameters.The assessment has been divided into three parts: Comparisons within and between the lakes, streams, and coastal sites, respectively; Temporal and spatial variation, predominantly within lakes and stream sites; and Relationships between the various chemical parameters. Beside comparisons between the sampling sites within the Forsmark area, comparisons have also been made with regional and national data from the latest Swedish National Survey (2000). The analyses of temporal and spatial variation have been concentrated on the freshwater systems in the Norra Bassaengen catchment area. This catchment area is the most comprehensively investigated, and it also includes the Bolundsfjaerden sub-catchment, which is the area where the continued site investigations will be concentrated. The relationships among the sampling sites, the catchment areas, as well as the chemical parameters investigated, were examined by applying PCA analyses on the lake and stream data. In general, the freshwater systems in the Forsmark area are characterised by small and shallow oligotrophic hardwater

  16. Supplement to the site observational work plan for the UMTRA Project Site at Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    1996-02-01

    The purpose of this document is to provide additional and more detailed information to supplement review of the site observational work plan (SOWP) for the Ambrosia Lake, New Mexico, Uranium Mill Tailings Remedial Action (UMTRA) Project site. This document includes a discussion of (1) the average linear velocity of the ground water in the alluvium; (2) the ground water quality of the alluvium, weathered Mancos Shale, and the Tres Hermanos-C Member of the Mancos Shale; and (3) the fate and transport of contaminants from the uppermost aquifer to the Westwater Canyon Member of the Morrison Formation. The data from a 1989 aquifer test were analyzed using the curve-matching software AQTESOLV and then compared with the original results. A hydrograph of the ground water elevations in monitoring wells screened in the alluvium is presented to show how the ground water elevations change with time. Stiff and Piper diagrams were created to describe the changes in ground water geochemistry in the alluvium/weathered Mancos Shale unit, the Tres Hermanos-C Sandstone unit, the Tres Hermanos-B Sandstone unit, and the Dakota Sandstone. Background information on other related topics such as site history, cell construction, soil characteristics, and well construction are presented in the SOWP. Figure 1 is a geologic cross section depicting the conceptual model of the hydrostratigraphy and ground water chemistry of the Ambrosia Lake site. Table 1 presents hydrogeologic information of each hydrostratigraphic unit

  17. Simulation of ground-water flow and land subsidence in the Antelope Valley ground-water basin, California

    Science.gov (United States)

    Leighton, David A.; Phillips, Steven P.

    2003-01-01

    Antelope Valley, California, is a topographically closed basin in the western part of the Mojave Desert, about 50 miles northeast of Los Angeles. The Antelope Valley ground-water basin is about 940 square miles and is separated from the northern part of Antelope Valley by faults and low-lying hills. Prior to 1972, ground water provided more than 90 percent of the total water supply in the valley; since 1972, it has provided between 50 and 90 percent. Most ground-water pumping in the valley occurs in the Antelope Valley ground-water basin, which includes the rapidly growing cities of Lancaster and Palmdale. Ground-water-level declines of more than 200 feet in some parts of the ground-water basin have resulted in an increase in pumping lifts, reduced well efficiency, and land subsidence of more than 6 feet in some areas. Future urban growth and limits on the supply of imported water may continue to increase reliance on ground water. To better understand the ground-water flow system and to develop a tool to aid in effectively managing the water resources, a numerical model of ground-water flow and land subsidence in the Antelope Valley ground-water basin was developed using old and new geohydrologic information. The ground-water flow system consists of three aquifers: the upper, middle, and lower aquifers. The aquifers, which were identified on the basis of the hydrologic properties, age, and depth of the unconsolidated deposits, consist of gravel, sand, silt, and clay alluvial deposits and clay and silty clay lacustrine deposits. Prior to ground-water development in the valley, recharge was primarily the infiltration of runoff from the surrounding mountains. Ground water flowed from the recharge areas to discharge areas around the playas where it discharged either from the aquifer system as evapotranspiration or from springs. Partial barriers to horizontal ground-water flow, such as faults, have been identified in the ground-water basin. Water-level declines owing to

  18. Evaluation of volatile organic compounds in two Mojave Desert basins-Mojave River and Antelope Valley-in San Bernardino, Los Angeles, and Kern Counties, California, June-October 2002

    Science.gov (United States)

    Densmore, Jill N.; Belitz, Kenneth; Wright, Michael T.; Dawson, Barbara J.; Johnson, Tyler D.

    2005-01-01

    The California Aquifer Susceptibility Assessment of the Ground-Water Ambient Monitoring and Assessment Program was developed to assess water quality and susceptibility of ground-water resources to contamination from surficial sources. This study focuses on the Mojave River and the Antelope Valley ground-water basins in southern California. Volatile organic compound (VOC) data were evaluated in conjunction with tritium data to determine a potential correlation with aquifer type, depth to top of perforations, and land use to VOC distribution and occurrence in the Mojave River and the Antelope Valley Basins. Detection frequencies for VOCs were compiled and compared to assess the distribution in each area. Explanatory variables were evaluated by comparing detection frequencies for VOCs and tritium and the number of compounds detected. Thirty-three wells were sampled in the Mojave River Basin (9 in the floodplain aquifer, 15 in the regional aquifer, and 9 in the sewered subset of the regional aquifer). Thirty-two wells were sampled in the Antelope Valley Basin. Quality-control samples also were collected to identify, quantify, and document bias and variability in the data. Results show that VOCs generally were detected slightly more often in the Antelope Valley Basin samples than in the Mojave River Basin samples. VOCs were detected more frequently in the floodplain aquifer than in the regional aquifer and the sewered subset. Tritium was detected more frequently in the Mojave River Basin samples than in the Antelope Valley Basin samples, and it was detected more frequently in the floodplain aquifer than in the regional aquifer and the sewered subset. Most of the samples collected in both basins for this study contained old water (water recharged prior to 1952). In general, in these desert basins, tritium need not be present for VOCs to be present. When VOCs were detected, young water (water recharge after 1952) was slightly more likely to be contaminated than old water

  19. Sedimentology, tephrostratigraphy, and chronology of the DEEP site sediment record, Lake Ohrid (Albania, FYROM)

    Science.gov (United States)

    Leicher, Niklas; Wagner, Bernd; Francke, Alexander; Just, Janna; Zanchetta, Giovanni; Sulpizio, Roberto; Giaccio, Biagio; Nomade, Sebastien

    2017-04-01

    Lake Ohrid, located on the Balkan Peninsula, is one of the very few lakes in the world that provides a continuous and high-resolution record of environmental change of >1.3 Ma. The sedimentary archive was drilled in spring 2013 within the scope of the International Continental Scientific Drilling Program (ICDP) and the Scientific Collaboration on Past Speciation Conditions in Lake Ohrid (SCOPSCO) project in order to investigate local and regional geological and paleoclimatic processes, as well as triggers of evolutionary patterns and endemic biodiversity. The continuous composite profile (584 m) of the main drill site DEEP was logged (XRF, MSCL) and subsampled for biogeochemical (TIC, TOC, TN, TS) and sedimentological (grain size) analyses. The lithology of the DEEP site indicates that the history of Lake Ohrid can roughly be separated into two parts, with the older section between 584 and 450 m depth being characterised by a sedimentary facies indicating shallow water conditions, which is likely younger than ca. 1.9 Ma. In the lowermost few meters of the succession gravels and pebbles hampered a deeper drilling penetration and indicate that fluvial conditions existed during the onset of lake formation. Together with geotectonic, seismic, and biological information, the data imply that the Ohrid basin formed by transtension during the Miocene, opened during the Pliocene and Pleistocene, and that the lake established between 1.9 and 1.3 Ma ago. The sediments of the younger part (DEEP site sequence and are subject of ongoing investigations aimed at identifying their specific volcanic sources and equivalent known tephra by using geochemical fingerprinting of glass fragments. This was already successfully approved for tephra horizons in the upper 247.8 m of the sequence, obtaining important chronological information from 11 well dated tephra layers. These tephrochronological constraints were complemented by ages obtained from tuning the consistent pattern of the

  20. Faunal communities at sites of gas- and oil-bearing fluids in Lake Baikal

    Science.gov (United States)

    Zemskaya, Tamara I.; Sitnikova, Tatiana Y.; Kiyashko, Sergei I.; Kalmychkov, Gennady V.; Pogodaeva, Tatiana V.; Mekhanikova, Irina V.; Naumova, Tatiana V.; Shubenkova, Olga V.; Chernitsina, Svetlana M.; Kotsar, Oleg V.; Chernyaev, Evgeny S.; Khlystov, Oleg M.

    2012-12-01

    Macro- and meiofaunal communities were examined at four geomorphologically distinct sites with different gas- and oil-bearing fluid characteristics in the northern, central and southern basins of Lake Baikal. All sites had elevated concentrations of bicarbonate, nitrate, sulphate and chloride ions in pore fluids, with highest values at the Frolikha vent. Elevated levels of iron ions were found in pore waters of the St. Petersburg methane seep and the Gorevoy Utes oil seep. The chemical composition of pore waters at the Malenky mud volcano was similar to that reported in earlier work. Consistent with published data, the Frolikha vent (northern basin) and the St. Petersburg methane seep (central basin) were characterised by methane of mixed genesis (thermogenic + biogenic), whereas the methane source was mainly thermogenic at the Gorevoy Utes oil seep (central basin) and biogenic at the Malenky mud volcano (southern basin). In contrast to marine seep ecosystems, the macrofauna was dominated only by amphipods, giant planarians and oligochaetes, whereas bivalves were absent; the meiofauna was similar to its marine counterpart, being dominated by nematodes, cyclops, harpacticoids and ostracods. A statistically significant positive relationship was revealed between faunal abundance and the availability of bacterial mats on seep sediments. Moreover, ANOVA tests showed significant increases in both meiozoobenthic and macrozoobenthic densities at "hot spot" vent/seep sites relative to discharge-free reference sites. The isotopic composition of carbon and nitrogen at various trophic levels of these benthic vent/seep communities was found to differ markedly from that reported by earlier studies for the pelagic and other benthic food webs in Lake Baikal. As in marine seeps, the macrofauna had variable isotopic signatures. Light δ13C and δ15N values suggest the utilization of chemosynthetically fixed and/or methane-derived organic matter. By contrast, the heavy δ13C

  1. Completion report for the UMTRA project Vitro processing site, Salt Lake City, Utah

    International Nuclear Information System (INIS)

    1996-08-01

    This completion report provides evidence that the final Salt Lake City, Utah, processing site property conditions are in accordance with the approval design and that all U.S. Environmental Protection Agency (EPA) standards have been satisfied. Included as appendixes to support the stated conclusions are the record drawings; a summary of grid test results; contract specifications and construction drawing and the EPA standards; the audit, inspection, and surveillance summary; the permit information; and project photographs. The principal objectives of remedial action at Salt Lake City were to remove the tailings from the former processing site, render the site free of contamination to EPA standards, and restore the site to the final design grade elevations. The final remedial action plan, which is approved by the U.S. Department of Energy and concurred upon by the U.S. Nuclear Regulator Commission and the state of Utah, contains the conceptual design used to develop the final approved design. During remedial action construction operations, conditions were encountered that required design features that differed form the conceptual design. These conditions and the associated design changes are noted in the record drawings. All remedial action activities were completed in conformance with the specifications and drawings. In the opinion of the state of Utah, the record drawings accurately reflect existing property conditions at the processing site

  2. Long-term surveillance plan for the Ambrosia Lake, New Mexico disposal site

    International Nuclear Information System (INIS)

    1995-11-01

    This long-term surveillance plan (LTSP) for the Uranium Mill Tailings Remedial Action (UMTRA) Project Ambrosia Lake disposal site in McKinley County, New Mexico, describes the US Department of Energy's (DOE) long-term care program for the disposal site. The DOE will carry out this program to ensure that the disposal cell continues to function as designed. This LTSP was prepared as a requirement for acceptance under the US Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials

  3. Long-term surveillance plan for the Ambrosia Lake, New Mexico disposal site

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-07-01

    This long-term surveillance plan (LTSP) for the Uranium Mill Tailings Remedial Action (UMTRA) Project Ambrosia Lake disposal site in McKinley County, New Mexico, describes the U.S. Department of Energy`s (DOE) long-term care program for the disposal site. The DOE will carry out this program to ensure that the disposal cell continues to function as designed. This LTSP was prepared as a requirement for acceptance under the U.S. Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials.

  4. Long-term surveillance plan for the Ambrosia Lake, New Mexico disposal site

    International Nuclear Information System (INIS)

    1996-07-01

    This long-term surveillance plan (LTSP) for the Uranium Mill Tailings Remedial Action (UMTRA) Project Ambrosia Lake disposal site in McKinley County, New Mexico, describes the U.S. Department of Energy's (DOE) long-term care program for the disposal site. The DOE will carry out this program to ensure that the disposal cell continues to function as designed. This LTSP was prepared as a requirement for acceptance under the U.S. Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials

  5. Lake-wide distribution of Dreissena in Lake Michigan, 1999

    Science.gov (United States)

    Fleischer, Guy W.; DeSorcie, Timothy J.; Holuszko, Jeffrey D.

    2001-01-01

    The Great Lakes Science Center has conducted lake-wide bottom trawl surveys of the fish community in Lake Michigan each fall since 1973. These systematic surveys are performed at depths of 9 to 110 m at each of seven index sites around Lake Michigan. Zebra mussel (Dreissena polymorpha) populations have expanded to all survey locations and at a level to sufficiently contribute to the bottom trawl catches. The quagga (Dreissena bugensis), recently reported in Lake Michigan, was likely in the catches though not recognized. Dreissena spp. biomass ranged from about 0.6 to 15 kg/ha at the various sites in 1999. Dreissenid mussels were found at depths of 9 to 82 m, with their peak biomass at 27 to 46 m. The colonization of these exotic mussels has ecological implications as well as potential ramifications on the ability to sample fish consistently and effectively with bottom trawls in Lake Michigan.

  6. Final Approval of California Air Plan Revision; Antelope Valley Air Quality Management District; VOCs From Motor Vehicle Assembly Coating Operations

    Science.gov (United States)

    EPA is taking final action to approve a revision to the Antelope Valley Air Quality Management District (AVAQMD) portion of the California SIP concerning the emissions of volatile organic compounds (VOCs) from motor vehicle assembly coating operations.

  7. Mercury pollution in the lake sediments and catchment soils of anthropogenically-disturbed sites across England.

    Science.gov (United States)

    Yang, Handong; Turner, Simon; Rose, Neil L

    2016-12-01

    Sediment cores and soil samples were taken from nine lakes and their catchments across England with varying degrees of direct human disturbance. Mercury (Hg) analysis demonstrated a range of impacts, many from local sources, resulting from differing historical and contemporary site usage and management. Lakes located in industrially important areas showed clear evidence for early Hg pollution with concentrations in sediments reaching 400-1600 ng g -1 prior to the mid-19th century. Control of inputs resulting from local management practices and a greater than 90% reduction in UK Hg emissions since 1970 were reflected by reduced Hg pollution in some lakes. However, having been a sink for Hg deposition for centuries, polluted catchment soils are now the major Hg source for most lakes and consequently recovery from reduced Hg deposition is being delayed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Estimating microcystin levels at recreational sites in western Lake Erie and Ohio

    Science.gov (United States)

    Francy, Donna S.; Brady, Amie M. G.; Ecker, Christopher D.; Graham, Jennifer L.; Stelzer, Erin A.; Struffolino, Pamela; Loftin, Keith A.

    2016-01-01

    Cyanobacterial harmful algal blooms (cyanoHABs) and associated toxins, such as microcystin, are a major global water-quality issue. Water-resource managers need tools to quickly predict when and where toxin-producing cyanoHABs will occur. This could be done by using site-specific models that estimate the potential for elevated toxin concentrations that cause public health concerns. With this study, samples were collected at three Ohio lakes to identify environmental and water-quality factors to develop linear-regression models to estimate microcystin levels. Measures of the algal community (phycocyanin, cyanobacterial biovolume, and cyanobacterial gene concentrations) and pH were most strongly correlated with microcystin concentrations. Cyanobacterial genes were quantified for general cyanobacteria, general Microcystis and Dolichospermum, and for microcystin synthetase (mcyE) for Microcystis, Dolichospermum, and Planktothrix. For phycocyanin, the relations were different between sites and were different between hand-held measurements on-site and nearby continuous monitor measurements for the same site. Continuous measurements of parameters such as phycocyanin, pH, and temperature over multiple days showed the highest correlations to microcystin concentrations. The development of models with high R2values (0.81–0.90), sensitivities (92%), and specificities (100%) for estimating microcystin concentrations above or below the Ohio Recreational Public Health Advisory level of 6 μg L−1 was demonstrated for one site; these statistics may change as more data are collected in subsequent years. This study showed that models could be developed for estimates of exceeding a microcystin threshold concentration at a recreational freshwater lake site, with potential to expand their use to provide relevant public health information to water resource managers and the public for both recreational and drinking waters.

  9. Comment and response document for the UMTRA Project vitro processing site completion report Salt Lake City, Utah. Revision 1

    International Nuclear Information System (INIS)

    1995-03-01

    This Comment and Response Document is a series of UMTRA document review forms regarding the UMTRA Project Vitro Processing Site Completion Report for Salt Lake City, Utah in March, 1995. The completion report provides evidence that the final Salt Lake City, Utah, processing site property conditions are in accordance with the approved design and that all U.S. Environmental Protection Agency (EPA) standards have been satisfied. Included as appendices to support the stated conclusions are the record drawings; a summary of grid test results; contract specifications and construction drawings, the EPA standards (40 CFR Part 192); the audit, inspection, and surveillance summary; the permit information; and project photographs. The principal objective of the remedial action at Salt Lake City is to remove the tailings from the processing site, render the site free of contamination to EPA standards, and restore the site to the final design grade elevations. Each section is evaluated in detail to check all aspects of above report, especially the inclusion of adequate verification data. Each review form contains a section entitled State of Utah Response and Action, which is an explanation or correction of DOE criticisms of the report

  10. 77 FR 12527 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2012-03-01

    ...EPA is proposing to approve revisions to the Antelope Valley Air Quality Management District (AVAQMD) and San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portions of the California State Implementation Plan (SIP). These revisions concern negative declarations for volatile organic compound (VOC) and oxides of sulfur source categories. We are proposing to approve these negative declarations under the Clean Air Act as amended in 1990 (CAA or the Act).

  11. Advanced Reservoir Characterization in the Antelope Shale to Establish the Viability of CO2 Enhanced Oil Recovery in California's Monterey Formation Siliceous Shales

    International Nuclear Information System (INIS)

    Morea, Michael F.

    1999-01-01

    The primary objective of this research is to conduct advanced reservoir characterization and modeling studies in the Antelope Shale reservoir. Characterization studies will be used to determine the technical feasibility of implementing a CO2 enhanced oil recovery project in the Antelope Shale in Buena Vista Hills Field. The Buena Vista Hills pilot CO2 project will demonstrate the economic viability and widespread applicability of CO2 flooding in fractured siliceous shale reservoirs of the San Joaquin Valley. The research consists of four primary work processes: (1) Reservoir Matrix and Fluid Characterization; (2) Fracture characterization; (3) reservoir Modeling and Simulation; and (4) CO2 Pilot Flood and Evaluation. Work done in these areas is subdivided into two phases or budget periods. The first phase of the project will focus on the application of a variety of advanced reservoir characterization techniques to determine the production characteristics of the Antelope Shale reservoir. Reservoir models based on the results of the characterization work will be used to evaluate how the reservoir will respond to secondary recovery and EOR processes. The second phase of the project will include the implementation and evaluation of an advanced enhanced oil recovery (EOR) pilot in the United Anticline (West Dome) of the Buena Vista Hills Field

  12. Geophysical investigations of the Olonium Roman site (Northern Como Lake)

    Science.gov (United States)

    Arlsan, Ermanno; Biella, Giancarlo; Boniolo, Graziano; Caporusso, Donatella; de Franco, Roberto; Lozej, Alfredo; Veronese, Luigi

    1999-03-01

    The study area is located at S. Agata (Gera Lario), a small center at the northern end of Como Lake, near the junction of Valchiavenna and Valtellina Valleys. This site played a strategic role since ancient times, providing the control on the communications routes to both the Como Lake and the Spluga and Septimer alpine passes. Since the end of the last century archaeological findings are reported in literature, also supported, from the early XI century, by archival documents confirming the existence of the `Olonium' settlement, an administrative and fiscal center of primary importance, as well as a parish amongst the most influential in the Como Lake area. Within an area of 45,000 m 2 an electrical survey has been carried out in conjunction with magnetic and GPR investigations. These studies have indicated the presence of a number of sub-areas characterized by significant anomalies defined by the overlapping of the results obtained from two or more geophysical methods. In two of such sub-areas, excavation tests have been conducted, which have brought to light a number of archaeological findings of interest. In one of the two sub-areas, which is characterized by the superimposition of electrical and radar anomalies, a deposit of large pebbles has been found. The origin of this deposit has not been ascertained, whether it is of fluvial origin, related to the deviation of the Adda river in the Pian di Spagna region in Roman times, or it is part of reclamation works, still of Roman times, of paleolacustrine marshes. The overlapping stratigraphy, however, suggests the development of fluvial channels between Roman and Low-Medieval times. In the other sub-area, excavations were carried out on sites defined by electrical and radar anomalies, and confirmed by the results from magnetic survey. The excavations brought to light, below the fluvial deposits, a large medieval edifice, which could be identified as the S. Stefano church abandoned in 1444. The church is built on

  13. Valuation of provisional and cultural services of a Ramsar site: A preliminary study on Rudrasagar lake, India

    Directory of Open Access Journals (Sweden)

    Moitree Taran

    2017-01-01

    Full Text Available Rudrasagar lake, a Ramsar site in India offers a variety of ecosystem services. The contribution of Rudrasagar lake to the society has not been estimated so far. The preliminary study aims to provide an economic valuation of the provisional and cultural services of the Rudrasagar lake. Official records of revenue collected by the Tourism Department of Tripura and a socio- economic survey was the source of information used in the economic valuation of the lake. The main provisional services provided by the lake are food (aquatic plants and fishes, fuel wood and timber whereas, the cultural services provided were boat raiding and tourism due to its historical importance. The provisioning and cultural services provided by the Rudrasagar lake are 40810 US$ and 33929.33 US$ per year respectively during the period of 2010-2015. The main threats to the wetland identified are increasing silt loads due to deforestation, expansion of agricultural land and land conversion due to population pressure. To alleviate the anthropogenic stress on the lake, better monitoring, planning and management are essential. By proper conservation and management it will be possible to enjoy the provisional and cultural services of the lake in a sustainable way.

  14. Pliocene and pleistocene hominid-bearing sites from west of lake turkana, kenya.

    Science.gov (United States)

    Harris, J M; Brown, F H; Leakey, M G; Walker, A C; Leakey, R E

    1988-01-01

    Pliocene and Pleistocene fossil localities near the western shoreline of Lake Turkana, ranging in age between 1 million and 3.5 million years in age, have produced important new hominid specimens including most of a Homo erectus skeleton and a relatively complete early robust australopithecine cranium. The lacustrine, fluviatile, and terrestrial strata are designated the Nachukui Formation, which is subdivided into eight members. The distribution of sedimentary facies within the Nachukui Formation suggests that, as today, the Labur and Murua Rith ranges formed the western margin of the basin and were drained by eastward-flowing rivers that fed into the forerunner of the present lake or a major river system. There is also stratigraphic evidence for tectonic movement during the deposition of these sediments. Twenty-three of the tuffs observed in the succession occur also in the Koobi Fora Formation east of the lake and in the Shungura Formation of the lower Omo Valley and permit precise correlation among these three localities. Fortyseven fossiliferous sites from West Turkana have yielded more than 1000 specimens of 93 mammalian species. The mammalian fossils represent nine sequential assemblages that augment information about faunal and environmental change from elsewhere in the basin.

  15. Scope of work-supplemental standards-related fieldwork - Salt Lake City UMTRA Project Site, Salt Lake City, Utah

    International Nuclear Information System (INIS)

    1996-01-01

    This scope of work governs the field effort to conduct transient in situ (hereafter referred to by the trademark name HydroPunch reg-sign) investigative subsurface logging and ground water sampling, and perform well point installation services at the U.S. Department of Energy's (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project site near Salt Lake City, Utah. The HydroPunch reg-sign and well point services subcontractor (the Subcontractor) shall provide services as stated herein to be used to investigate the subsurface, collect and analyze ground water samples, and install shallow well points

  16. An exceptional case of historical outbreeding in African sable antelope populations

    DEFF Research Database (Denmark)

    Pitra, C.; Hansen, Anders J.; Lieckfeldt, D.

    2002-01-01

    ) sequences analysed from 95 individuals representing 17 sampling locations scattered through the African miombo (Brachystegia) woodland ecosystem] and phylogeographical statistical procedures (gene genealogy, nested cladistic and admixture proportion analyses), we (i) give a detailed dissection...... of the geographical genetic structure of Hippotragus niger; (ii) infer the processes and events potentially involved in the population history; and (iii) trace extensive introgressive hybridization in the species. The present-day sable antelope population shows a tripartite pattern of genetic subdivision representing...... West Tanzanian, Kenya/East Tanzanian and Southern Africa locations. Nested clade analysis revealed that past allopatric fragmentation, caused probably by habitat discontinuities associated with the East African Rift Valley system, together with intermediary episodic long-distance colonization...

  17. 77 FR 12491 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2012-03-01

    ...EPA is taking direct final action to approve revisions to the Antelope Valley Air Quality Management District (AVAQMD) and San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portions of the California State Implementation Plan (SIP). These revisions concern negative declarations for volatile organic compound (VOC) and oxides of sulfur source categories for the AVAQMD and SJVUAPCD. We are approving these negative declarations under the Clean Air Act as amended in 1990 (CAA or the Act).

  18. Bayesian, Maximum Parsimony and UPGMA Models for Inferring the Phylogenies of Antelopes Using Mitochondrial Markers

    OpenAIRE

    Khan, Haseeb A.; Arif, Ibrahim A.; Bahkali, Ali H.; Al Farhan, Ahmad H.; Al Homaidan, Ali A.

    2008-01-01

    This investigation was aimed to compare the inference of antelope phylogenies resulting from the 16S rRNA, cytochrome-b (cyt-b) and d-loop segments of mitochondrial DNA using three different computational models including Bayesian (BA), maximum parsimony (MP) and unweighted pair group method with arithmetic mean (UPGMA). The respective nucleotide sequences of three Oryx species (Oryx leucoryx, Oryx dammah and Oryx gazella) and an out-group (Addax nasomaculatus) were aligned and subjected to B...

  19. Health evaluation of a pronghorn antelope population in Oregon

    Science.gov (United States)

    Dunbar, M.R.; Velarde, Roser; Gregg, M.A.; Bray, M.

    1999-01-01

    During 1996 and 1997, the U.S. Fish and Wildlife Service conducted a study to determine the cause(s) of population decline and low survival of pronghorn antelope (Antilocapra americana) fawns on Hart Mountain National Antelope Refuge (HMNAR) located in southeastern Oregon (USA). As part of that study, blood, fecal, and tissue samples from 104 neonatal fawns, 40 adult does, and nine adult male pronghorns were collected to conduct a health evaluation of the population. Physiological parameters related to nutrition and/or disease were studied. No abnormalities were found in the complete blood cell counts of adults (n = 40) or fawns (n = 44 to 67). Serum total protein and blood urea nitrogen (BUN) levels were lower compared to other pronghorn populations. Does had mean BUN values significantly lower (P the does' marginal values in about 3 days Whole blood, serum and liver selenium (Se) levels were considered marginal to low in most segments of the pronghorn population. However, serum levels of vitamin E (range 1.98 to 3.27 ??g/ml), as determined from the does captured in March, were apparently sufficient to offset any signs of Se deficiency. No clinical signs of Cu or Se deficiency were observed. Fifty-five of 87 dead fawns were necropsied. Trauma, due to predation by coyotes (Canis latrans), accounted for 62% of the mortality during mid-May to mid-July of each year. Other causes included predation by golden eagles (Aquila chrysaetos) (4%), dystocia (2%), septicemic pasteurellosis (4%), starvation (5%), and unknown (23%). Adult females were tested for serum neutralizing antibodies to Brucella spp. (n = 20, negative), Leptospira interrogans (n = 20, negative), bluetongue virus (n = 20, 35% positive), epizootic hemorrhagic disease virus (n = 20, 30% positive), respiratory syncytial virus (n = 18, negative), parainfluenza virus type 3 (n = 18, 67% positive), infectious bovine rhinotracheitis (n = 18, negative), and bovine viral diarrhea (n = 18, negative). Considering the

  20. Evapotranspiration from marsh and open-water sites at Upper Klamath Lake, Oregon, 2008--2010

    Science.gov (United States)

    Stannard, David I.; Gannett, Marshall W.; Polette, Danial J.; Cameron, Jason M.; Waibel, M. Scott; Spears, J. Mark

    2013-01-01

    Water allocation in the Upper Klamath Basin has become difficult in recent years due to the increase in occurrence of drought coupled with continued high water demand. Upper Klamath Lake is a central component of water distribution, supplying water downstream to the Klamath River, supplying water for irrigation diversions, and providing habitat for various species within the lake and surrounding wetlands. Evapotranspiration (ET) is a major component of the hydrologic budget of the lake and wetlands, and yet estimates of ET have been elusive—quantified only as part of a lumped term including other substantial water-budget components. To improve understanding of ET losses from the lake and wetlands, measurements of ET were made from May 2008 through September 2010. The eddy-covariance method was used to monitor ET at two wetland sites continuously during this study period and the Bowen-ratio energy-balance method was used to monitor open-water lake evaporation at two sites during the warmer months of the 3 study years. Vegetation at one wetland site (the bulrush site) consists of a virtual monoculture of hardstem bulrush (formerly Scirpus acutus, now Schoenoplectus acutus), and at the other site (the mixed site) consists of a mix of about 70 percent bulrush, 15 percent cattail (Typha latifolia), and 15 percent wocus (Nuphar polysepalum). Measured ET at these two sites was very similar (means were ±2.5 percent) and mean wetland ET is computed as a 70 to 30 percent weighted average of the bulrush and mixed sites, respectively, based on community-type distribution estimated from satellite imagery. Biweekly means of wetland ET typically vary from maximum values of around 6 to 7 millimeters per day during midsummer, to minimum values of less than 1 mm/d during midwinter. This strong annual signal primarily reflects life-cycle changes in the wetland vegetation, and the annual variation of radiative input to the surface and resulting temperature. The perennial vegetation

  1. [Identification of ecological corridors for Tibetan antelope and assessment of their human disturbances in the alpine desert of Qinghai-Tibet Plateau].

    Science.gov (United States)

    Zhuge, Hai-jin; Lin, Dan-qi; Li, Xiao-wen

    2015-08-01

    The alpine desert of Qinghai-Tibet Plateau (QTP) provides the largest habitats for those endangered ungulates (e.g., Tibetan antelope, Tibetan Kiang and wild yak) on the earth. However, human disturbance especially infrastructure constructions (e.g., railway & highway) has increasingly fragmented the habitats of those endangered ungulates by disturbing and interrupting their ecological corridors for their seasonal migration. Aiming at identifying the potential ecological corridors for Tibetan antelope, a GIS-based model-Linkage Mapper was used to model and detect the potential ecological corridors of Tibetan antelope based on the principle of least cost path. Three categories of ecological corridors, i. e., closed (inside reserves), linking (linking the reserves) and open (starting from reserve but ending outside) corridors were distinguished by their spatial interactions with existing major national nature reserves (i.e., Altun, Kekexili and Qiangtang NNRs) in the alpine desert of QTP, and their spatial patterns, conservation status associated with human disturbance were also examined. Although our research indicated a general ecological integration of both habitats and ecological corridors in the alpine desert ecosystem, increasing human disturbance should not be ignored, which particularly partially undermined the functioning of those ecological corridors linking the nature reserves. Considering disadvantages of prevailing separate administrative structure of nature reserve on the effective conservation of ecological corridors for those endangered ungulates, a coordinative conservation network among these major national nature reserves should be established to ensure the unified trans-boundary conservation efforts and to enhance its overall conservation efficacy by sharing information, knowledge and optimizing conservation resources.

  2. 78 FR 21581 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2013-04-11

    ...EPA is proposing to approve revisions to the Antelope Valley Air Quality Management District (AVAQMD), Monterey Bay Unified Air Pollution Control District (MBUAPCD) and Santa Barbara County Air Pollution Control District (SCAPCD) portions of the California State Implementation Plan (SIP). We are proposing to approve revisions local rules that address emission statements for AVAQMD, rule rescissions that address public records for MBUAPCD, and define terms for SBCAPCD, under the Clean Air Act as amended in 1990 (CAA or the Act).

  3. High-frequency acoustic imaging of L Lake Phase 4 [Savannah River Site, South Carolina

    International Nuclear Information System (INIS)

    Dunn, D.L.; Sjostrom, Keith J.; Leist, Rodney L.; Harmon, Thomas S. Jr.

    1997-01-01

    The objective of the seismic reflection and side scan sonar survey is to determine the location, aerial extent, and depth of burial pits situated along the reservoir bottom of L Lake, Savannah River Site, SC. The results will be used in the overall characterization of L Lake by providing continuous profile line coverage of the bottom and subbottom sediment structure along the entire length of the project area. The results are also intended to supplement previous scientific information obtained from soil samples, aerial photography, and radiometric studies. Resultant information will be used as input for an Environmental Impact Statement of the site. Overall, the seismic reflection data will provide better descriptions of variations in the actual subbottom conditions and help identify the differing sediment layers. The side scan sonar will help identify the location of the burial pits and any other features on the bottom of the reservoir. A 3.5 kiloHertz (kHz), high resolution subbottom profiling system and an EG and G Model 260 side scan sonar system were used to meet the primary objectives of the investigation

  4. The Ambrosia Lake project archaeological investigations of three small sites associated with the southern Chacoan outlier of Kin Nizhoni, McKinley County, New Mexico

    International Nuclear Information System (INIS)

    Cullington, B.J.

    1990-01-01

    During the fall of 1987, Complete Archaeological Service Associates conducted mitigative excavations at three sites (LA50363, LA50364, and LA50371) in McKinley County, New Mexico. These sites are adjacent to the Phillips/United Nuclear Inactive Uranium Mill and Tailings site at Ambrosia Lake, New Mexico. The primary deposition at each of these sites appears to be related to a Pueblo II or Bonito Phase occupation. Temporal placement is based primarily on the cross dating of ceramics and archaeomagnetic determinations when possible. No tree-ring or radiocarbon samples are available from these sites. These Ambrosia Lake sites indicate that this area was occupied primarily by Pueblo II people who may have had close social, economic, and ceremonial ties with the people living at the nuclear community of Lower Nizhoni about 3 km south-southeast. The later component at LA50364 indicates a Pueblo III occupation by people who may have had similar ties to the people of the Kin Nizhoni nuclear community. The Ambrosia Lake sites, then, provide important information on the structure of subnuclear communities within the southern Chaco periphery

  5. Assessment of land use/land cover dynamics of Tso Moriri Lake, a Ramsar site in India.

    Science.gov (United States)

    Gupta, Sharad Kumar; Shukla, Dericks Praise

    2016-12-01

    Wetlands accounts for 6% area of the Earth's land cover and nearly 17% of the Hindu Kush Himalayan region. They are of utmost importance to climate dynamics and are critical links between terrestrial and aquatic ecosystems. Despite the need of high attention towards conserving and managing wetland resources, mapping them is a least practiced activity. This study shows the temporal change in land use and land cover pattern of Tso Moriri Lake, the highest altitude lake in India and designated as Ramsar site in year 2002, using multi-sensor and multi-date imagery. Due to change in hydro-meteorological conditions of the region, this lake area has been reduced. Since the lake recharge is dependent on snowmelt, hence change in climatic conditions (less snowfall in winters), to a certain extent, is also responsible for the decrease in water level and water spread of the lake. The result shows that the lake area has reduced approximately 2 km 2 in the last 15 years, and also, agriculture, grasslands, and vegetation cover have increased to a significant extent. Agricultural land and grasslands have doubled while the vegetation cover has increased more than six times, showing the coupled effect of climate change and anthropogenic activities. Trend of temperature and precipitation corroborates the effects of climate change in this region.

  6. Population trends of antelopes in Waza National Park (Cameroon) from 1960 to 2001: The interacting effects of rainfall, flooding and human interventions

    NARCIS (Netherlands)

    Scholte, P.; Adam, S.; Serge, B.K.

    2007-01-01

    Antelopes are prominent wildlife in Waza National Park, situated in Sahelo-Sudanian Cameroon, which has witnessed dramatic changes in rainfall and flooding. To assess their impacts, we reviewed 26 aerial and terrestrial surveys, comprising total, transect and localized counts. Estimated numbers of

  7. 77 FR 26475 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2012-05-04

    ...EPA is proposing to approve revisions to the Antelope Valley Air Quality Management District (AVAQMD), Eastern Kern Air Pollution Control District (EKAPCD), and Santa Barbara County Air Pollution Control District (SBCAPCD) portions of the California State Implementation Plan (SIP). We are proposing to approve revisions to local rules that define terms used in other air pollution regulations in these areas and a rule rescission that address Petroleum Coke Calcining Operations--Oxides of Sulfur, under the Clean Air Act as amended in 1990 (CAA or the Act).

  8. Lakes, Lagerstaetten, and Evolution

    Science.gov (United States)

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

    2001-12-01

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

  9. Questioning the Origin of the Great Salt Lake "Microbialites"

    Science.gov (United States)

    Frantz, C.; Matyjasik, M.; Newell, D. L.; Vanden Berg, M. D.; Park, C.

    2017-12-01

    The Great Salt Lake (GSL) of Utah contains abundant carbonate mounds that have been described in the literature as "biostromes", "bioherms", "stromatolites", and "microbialites". The structures are commonly cited as being rare examples of modern lacustrine microbialites, which implies that they are actively-forming and biogenic. Indeed, at least in some regions of the lake, the mounds are covered in a mixed community of cyanobacteria, algae, insect larval casings, microbial heterotrophs, and other organisms that is thought to contribute significantly to benthic primary productivity in GSL. However, the presence of a modern surface microbial community does not implicate a biogenic or modern origin for the mounds. The few studies to date GSL microbialites indicate that they are ancient, with radiocarbon calendar ages in the late Pleistocene and Holocene ( 13 - 3 cal ka). However, could they still be actively growing, and are the surface microbial communities playing a role? Here, we present results of a suite geochemical measurements used to constrain parameters—including groundwater seepage—influencing carbonate saturation and precipitation in the vicinity of one currently-submerged "microbialite reef" on the northern shore of Antelope Island in the South Arm of GSL. Our data suggests that calcium-charged brackish groundwater input to the lake through a permeable substratum in this location results in locally supersaturated conditions for aragonite, which could lead to modern, abiogenic mineralization. In addition, a series of laboratory experiments suggest that the modern surface microbial communities that coat the mounds do not appreciably facilitate carbonate precipitation in simulated GSL conditions, although they may serve as a template for precipitation when local waters become supersaturated.

  10. Hydrogeologic characterization of the former Vitro processing site, Salt Lake City, Utah

    International Nuclear Information System (INIS)

    1993-01-01

    During fiscal year (FY) 1992, the US Department of Energy received Congressional direction to investigate whether contamination from former processing activities is present in groundwater and soils at the former Vitro processing site in Salt Lake City, Utah. A total of $100,000 was appropriated for this activity. The surface of the Vitro site was cleaned up by the state of Utah under the Uranium Mill Tailings Remedial Action (UMTRA) Project during the mid- to late 1980s. The basis for the directive was the desire of the site owners, the Central Valley Water Reclamation Facility (CVWRF), to develop the site. This report, as well as the final Vitro Site Certification Report and the Clive Completion Report (both to be prepared and submitted by the state of Utah), will have to be reviewed and concurred with by the US Nuclear Regulatory Commission (NRC) prior to release of the Vitro site for restricted development. The groundwater and soil investigation was performed by the Technical Assistance Contractor (TAC) to the DOE UMTRA Project Office during FY92. The investigation at the Vitro site consisted of the installation of monitoring wells and soil borings, aquifer testing, and the collection and analyses of groundwater and soil samples. This report presents the results of this hydrogeologic investigation

  11. 77 FR 26448 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2012-05-04

    ...EPA is taking direct final action to approve revisions to the Antelope Valley Air Quality Management District (AVAQMD), Eastern Kern Air Pollution Control District (EKAPCD), and Santa Barbara County Air Pollution Control District (SBCAPCD) portions of the California State Implementation Plan (SIP). Under authority of the Clean Air Act as amended in 1990 (CAA or the Act), we are approving local rules that define terms used in other air pollution regulation in these areas and approving a rule rescission that addresses Petroleum Coke Calcining Operations--Oxides of Sulfur.

  12. Remedial action plan and site conceptual design for stabilization of the inactive uranium mill tailings site at Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    Matthews, M.L.; Mitzelfelt, R.

    1991-11-01

    This Remedial Action Plan (RAP) has been developed to serve a dual purpose. It presents the series of activities that is proposed by the US Department of Energy (DOE) to stabilize and control radioactive materials at the inactive Phillips/United Nuclear uranium processing site designated as the Ambrosia Lake site in McKinley County, New Mexico. It also serves to document the concurrence of both State of New Mexico and the US Nuclear Regulatory Commission (NRC) in the remedial action. This agreement, upon execution by the DOE and the state and concurrence by NRC, becomes Appendix B of the Cooperative Agreement

  13. Natural recharge estimation and uncertainty analysis of an adjudicated groundwater basin using a regional-scale flow and subsidence model (Antelope Valley, California, USA)

    Science.gov (United States)

    Siade, Adam J.; Nishikawa, Tracy; Martin, Peter

    2015-01-01

    Groundwater has provided 50–90 % of the total water supply in Antelope Valley, California (USA). The associated groundwater-level declines have led the Los Angeles County Superior Court of California to recently rule that the Antelope Valley groundwater basin is in overdraft, i.e., annual pumpage exceeds annual recharge. Natural recharge consists primarily of mountain-front recharge and is an important component of the total groundwater budget in Antelope Valley. Therefore, natural recharge plays a major role in the Court’s decision. The exact quantity and distribution of natural recharge is uncertain, with total estimates from previous studies ranging from 37 to 200 gigaliters per year (GL/year). In order to better understand the uncertainty associated with natural recharge and to provide a tool for groundwater management, a numerical model of groundwater flow and land subsidence was developed. The transient model was calibrated using PEST with water-level and subsidence data; prior information was incorporated through the use of Tikhonov regularization. The calibrated estimate of natural recharge was 36 GL/year, which is appreciably less than the value used by the court (74 GL/year). The effect of parameter uncertainty on the estimation of natural recharge was addressed using the Null-Space Monte Carlo method. A Pareto trade-off method was also used to portray the reasonableness of larger natural recharge rates. The reasonableness of the 74 GL/year value and the effect of uncertain pumpage rates were also evaluated. The uncertainty analyses indicate that the total natural recharge likely ranges between 34.5 and 54.3 GL/year.

  14. Real-estate lakes

    Science.gov (United States)

    Rickert, David A.; Spieker, Andrew Maute

    1971-01-01

    Since the dawn of civilization waterfront land has been an irresistible attraction to man. Throughout history he has sought out locations fronting on oceans, rivers, and lakes. Originally sought for proximity .to water supply and transportation, such locations are now sought more for their esthetic qualities and for recreation. Usable natural waterfront property is limited, however, and the more desirable sites in many of our urban areas have already been taken. The lack of available waterfront sites has led to the creation of many artificial bodies of water. The rapid suburbanization that has characterized urban growth in America since the end of World War II, together with increasing affluence and le-isure time, has created a ready market for waterfront property. Accordingly, lake-centered subdivisions and developments dot the suburban landscape in many of our major urban areas. Literally thousands of lakes surrounded by homes have materialized during this period of rapid growth. Recently, several "new town" communities have been planned around this lake-centered concept. A lake can be either an asset or a liaoility to a community. A clean, clear, attractively landscaped lake is a definite asset, whereas a weed-choked, foul-smelling mudhole is a distinct liability. The urban environment poses both problems and imaginative opportunities in the development of lakes. Creation of a lake causes changes in all aspects of the environment. Hydrologic systems and ecological patterns are usually most severely altered. The developer should be aware of the potential changes; it is not sufficient merely to build a dam across a stream or to dig a hole in the ground. Development of Gl a successful lake requires careful planning for site selection and design, followed by thorough and cc ntinual management. The purpose of this report is to describe the characteristics of real-estate lakes, to pinpoint potential pmblems, and to suggest possible planning and management guidelines

  15. Water Budgets of the Walker River Basin and Walker Lake, California and Nevada

    Science.gov (United States)

    Lopes, Thomas J.; Allander, Kip K.

    2009-01-01

    The Walker River is the main source of inflow to Walker Lake, a closed-basin lake in west-central Nevada. The only outflow from Walker Lake is evaporation from the lake surface. Between 1882 and 2008, upstream agricultural diversions resulted in a lake-level decline of more than 150 feet and storage loss of 7,400,000 acre-feet. Evaporative concentration increased dissolved solids from 2,500 to 17,000 milligrams per liter. The increase in salinity threatens the survival of the Lahontan cutthroat trout, a native species listed as threatened under the Endangered Species Act. This report describes streamflow in the Walker River basin and an updated water budget of Walker Lake with emphasis on the lower Walker River basin downstream from Wabuska, Nevada. Water budgets are based on average annual flows for a 30-year period (1971-2000). Total surface-water inflow to the upper Walker River basin upstream from Wabuska was estimated to be 387,000 acre-feet per year (acre-ft/yr). About 223,000 acre-ft/yr (58 percent) is from the West Fork of the Walker River; 145,000 acre-ft/yr (37 percent) is from the East Fork of the Walker River; 17,000 acre-ft/yr (4 percent) is from the Sweetwater Range; and 2,000 acre-ft/yr (less than 1 percent) is from the Bodie Mountains, Pine Grove Hills, and western Wassuk Range. Outflow from the upper Walker River basin is 138,000 acre-ft/yr at Wabuska. About 249,000 acre-ft/yr (64 percent) of inflow is diverted for irrigation, transpired by riparian vegetation, evaporates from lakes and reservoirs, and recharges alluvial aquifers. Stream losses in Antelope, Smith, and Bridgeport Valleys are due to evaporation from reservoirs and agricultural diversions with negligible stream infiltration or riparian evapotranspiration. Diversion rates in Antelope and Smith Valleys were estimated to be 3.0 feet per year (ft/yr) in each valley. Irrigated fields receive an additional 0.8 ft of precipitation, groundwater pumpage, or both for a total applied-water rate

  16. Systematically variable planktonic carbon metabolism along a land-to-lake gradient in a Great Lakes coastal zone.

    Science.gov (United States)

    Weinke, Anthony D; Kendall, Scott T; Kroll, Daniel J; Strickler, Eric A; Weinert, Maggie E; Holcomb, Thomas M; Defore, Angela A; Dila, Deborah K; Snider, Michael J; Gereaux, Leon C; Biddanda, Bopaiah A

    2014-11-01

    During the summers of 2002-2013, we measured rates of carbon metabolism in surface waters of six sites across a land-to-lake gradient from the upstream end of drowned river-mouth Muskegon Lake (ML) (freshwater estuary) to 19 km offshore in Lake Michigan (LM) (a Great Lake). Despite considerable inter-year variability, the average rates of gross production (GP), respiration (R) and net production (NP) across ML (604 ± 58, 222 ± 22 and 381 ± 52 µg C L -1 day -1 , respectively) decreased steeply in the furthest offshore LM site (22 ± 3, 55 ± 17 and -33 ± 15 µg C L -1 day -1 , respectively). Along this land-to-lake gradient, GP decreased by 96 ± 1%, whereas R only decreased by 75 ± 9%, variably influencing the carbon balance along this coastal zone. All ML sites were consistently net autotrophic (mean GP:R = 2.7), while the furthest offshore LM site was net heterotrophic (mean GP:R = 0.4). Our study suggests that pelagic waters of this Great Lakes coastal estuary are net carbon sinks that transition into net carbon sources offshore. Reactive and dynamic estuarine coastal zones everywhere may contribute similarly to regional and global carbon cycles.

  17. Identification of a novel Babesia sp. from a sable antelope (Hippotragus niger Harris, 1838).

    Science.gov (United States)

    Oosthuizen, Marinda C; Zweygarth, Erich; Collins, Nicola E; Troskie, Milana; Penzhorn, Banie L

    2008-07-01

    Babesiosis in a sable antelope (Hippotragus niger Harris, 1838) was first reported in 1930; the parasite was named Babesia irvinesmithi. Recently, specimens from an adult sable that presented with a sudden onset of disease and that subsequently died during immobilization were submitted for molecular characterization. Microscopic examination of thin blood smears revealed the presence of small piroplasms. DNA was extracted from blood samples; the V4 variable region of the 18S rRNA gene was amplified and analyzed using the reverse line blot (RLB) assay. Amplicons did not hybridize with any of the Babesia or Theileria species-specific probes present on the blot and hybridized only with a Babesia or Theileria genus-specific probe, suggesting the presence of a novel species. The full-length 18S rRNA gene sequence was obtained and aligned with published sequences of related genera, and phylogenetic trees were constructed. Sequence similarity analyses indicated that a Babesia species, designated Babesia sp. (sable), was present. The sequence showed its highest similarity to B. orientalis and to an unnamed Babesia species previously detected in bovine samples. The latter was later established to be Babesia occultans. A Babesia sp. (sable)-specific RLB oligonucleotide probe was designed and used to screen 200 South African sable samples, but so far, no other sample has been found to be positive for the presence of Babesia sp. (sable) DNA. In summary, we identified a novel piroplasm parasite from a sable antelope that died from an unknown illness. While the parasite was observed in blood smears, there is no direct evidence that it was the cause of death.

  18. Detection of Viral Hemorrhagic Septicemia Virus by Quantitative Reverse Transcription Polymerase Chain Reaction from Two Fish Species at Two Sites in Lake Superior

    Science.gov (United States)

    Cornwell, Emily R.; Eckerlin, Geofrey E.; Getchell, Rodman G.; Groocock, Geoffrey H.; Thompson, Tarin M.; Batts, William N.; Casey, Rufina N.; Kurath, Gael; Winton, James R.; Bowser, Paul R.; Bain, Mark B.; Casey, James W.

    2011-01-01

    Viral hemorrhagic septicemia virus (VHSV) was first detected in the Laurentian Great Lakes in 2005 during a mortality event in the Bay of Quinte, Lake Ontario. Subsequent analysis of archived samples determined that the first known isolation of VHSV in the Laurentian Great Lakes was from a muskellunge Esox masquinongy collected in Lake St. Clair in 2003. By the end of 2008, mortality events and viral isolations had occurred in all of the Laurentian Great Lakes except Lake Superior. In 2009, a focused disease surveillance program was designed to determine whether VHSV was also present in Lake Superior. In this survey, 874 fish from 7 sites along the U.S. shoreline of Lake Superior were collected during June 2009. Collections were focused on nearshore species known to be susceptible to VHSV. All fish were dissected individually by using aseptic techniques and were tested for the presence of VHSV genetic material by use of a quantitative reverse transcription (qRT) polymerase chain reaction (PCR) targeting the viral nucleoprotein gene. Seventeen fish from two host species at two different sites tested positive at low levels for VHSV. All attempts to isolate virus in cell culture were unsuccessful. However, the presence of viral RNA was confirmed independently in five fish by using a nested PCR that targeted the glycoprotein (G) gene. Partial G gene sequences obtained from three fish were identical to the corresponding sequence from the original 2003 VHSV isolate (MI03) from muskellunge. These detections represent the earliest evidence for the presence of VHSV in Lake Superior and illustrate the utility of the highly sensitive qRT-PCR assay for disease surveillance in aquatic animals.

  19. Baseline risk assessment of ground water contamination at the uranium mill tailings site Salt Lake City, Utah

    Energy Technology Data Exchange (ETDEWEB)

    1994-09-01

    This baseline risk assessment of groundwater contamination at the uranium mill tailings site near Salt Lake City, Utah, evaluates potential public health or environmental impacts resulting from ground water contamination at the former uranium ore processing site. The tailings and other contaminated material at this site were placed in a disposal cell located at Clive, Utah, in 1987 by the US Department of Energy`s Uranium Mill Tailings Remedial Action (UMTRA) Project. The second phase of the UMTRA Project is to evaluate residual ground water contamination at the former uranium processing site, known as the Vitro processing site. This risk assessment is the first site-specific document under the Ground Water Project. It will help determine the appropriate remedial action for contaminated ground water at the site.

  20. Baseline risk assessment of ground water contamination at the uranium mill tailings site Salt Lake City, Utah

    International Nuclear Information System (INIS)

    1994-09-01

    This baseline risk assessment of groundwater contamination at the uranium mill tailings site near Salt Lake City, Utah, evaluates potential public health or environmental impacts resulting from ground water contamination at the former uranium ore processing site. The tailings and other contaminated material at this site were placed in a disposal cell located at Clive, Utah, in 1987 by the US Department of Energy's Uranium Mill Tailings Remedial Action (UMTRA) Project. The second phase of the UMTRA Project is to evaluate residual ground water contamination at the former uranium processing site, known as the Vitro processing site. This risk assessment is the first site-specific document under the Ground Water Project. It will help determine the appropriate remedial action for contaminated ground water at the site

  1. Microbial communities and fecal indicator bacteria associated with Cladophora mats on beach sites along Lake Michigan shores.

    Science.gov (United States)

    Olapade, Ola A; Depas, Morgan M; Jensen, Erika T; McLellan, Sandra L

    2006-03-01

    A high biomasses of Cladophora, a filamentous green alga, is found mainly during the summer along the shores of Lake Michigan. In this study, the abundance and persistence of the fecal indicator bacterium Escherichia coli and sulfate-reducing bacteria (SRB) on Cladophora mats collected at Lake Michigan beaches were evaluated using both culture-based and molecular analyses. Additionally, 16S rRNA gene cloning and sequencing were used to examine the bacterial community composition. Overall, E. coli was detected in all 63 samples obtained from 11 sites, and the average levels at most beaches ranged from 2,700 CFU/100 g (wet weight) of Cladophora to 7,500 CFU/100 g of Cladophora. However, three beaches were found to have site average E. coli densities of 12,800, 21,130, and 27,950 CFU/100 g of Cladophora. The E. coli levels in the lake water collected at the same time from these three sites were less than the recommended U.S. Environmental Protection Agency limit, 235 CFU/100 ml. E. coli also persisted on Cladophora mats in microcosms at room temperature for more than 7 days, and in some experiments it persisted for as long as 28 days. The SRB densities on Cladophora mats were relatively high, ranging from 4.4x10(6) cells/g (6.64 log CFU/g) to 5.73x10(6) cells/g (6.76 log CFU/g) and accounting for between 20% and 27% of the total bacterial counts. Partial sequences of the 16S rRNA gene clones revealed a phylogenetically diverse community, in which the Cytophaga-Flavobacterium-Bacteroides cluster and the low-G+C-content gram-positive bacteria were the dominant organisms, accounting for 40% and 12.8%, respectively, of the total clone library. These results further reveal the potential public health and ecological significance of Cladophora mats that are commonly found along the shoreline of Lake Michigan, especially with regard to the potential to harbor microorganisms associated with fecal pollution and odor-causing bacteria.

  2. In-Flight Validation of Mid and Thermal Infrared Remotely Sensed Data Using the Lake Tahoe and Salton Sea Automated Validation Sites

    Science.gov (United States)

    Hook, Simon J.

    2008-01-01

    The presentation includes an introduction, Lake Tahoe site layout and measurements, Salton Sea site layout and measurements, field instrument calibration and cross-calculations, data reduction methodology and error budgets, and example results for MODIS. Summary and conclusions are: 1) Lake Tahoe CA/NV automated validation site was established in 1999 to assess radiometric accuracy of satellite and airborne mid and thermal infrared data and products. Water surface temperatures range from 4-25C.2) Salton Sea CA automated validation site was established in 2008 to broaden range of available water surface temperatures and atmospheric water vapor test cases. Water surface temperatures range from 15-35C. 3) Sites provide all information necessary for validation every 2 mins (bulk temperature, skin temperature, air temperature, wind speed, wind direction, net radiation, relative humidity). 4) Sites have been used to validate mid and thermal infrared data and products from: ASTER, AATSR, ATSR2, MODIS-Terra, MODIS-Aqua, Landsat 5, Landsat 7, MTI, TES, MASTER, MAS. 5) Approximately 10 years of data available to help validate AVHRR.

  3. Alternative management techniques for the uranium mill tailings site at Salt Lake City, UT

    International Nuclear Information System (INIS)

    Rogers, V.C.; Goldsmith, W.A.; Haywood, F.F.; Gantner, G.K.

    1976-01-01

    The concentrations of 226 Ra and other uranium-chain radionuclides present in tailings piles at uranium-milling sites are on the order of 10 3 times higher than those usually found in soil-surface minerals. The public radiation exposure attributable to these sites is primarily due to inhalation of 222 Rn progeny. This paper presents the radiological assessment of the uranium-milling site at Salt Lake City, Utah. Adverse health effects are estimated from present and projected public radiation exposures. Three alternative remedial action measures can be used to reduce radiation exposures: (1) decontamination of offsite areas contaminated by tailings materials; (2) covering the tailings with contamination-free material; and (3) removal of the tailings to a more remote location. These three measures are examined in terms of costs incurred and serious health effects avoided

  4. Radiological surveillance of Remedial Action activities at the processing site, Ambrosia Lake, New Mexico, April 12--16, 1993. Final report

    International Nuclear Information System (INIS)

    1993-04-01

    The Uranium Mill Tailings Remedial Action (UMTRA) Project's Technical Assistance Contractor (TAC) performed a radiological surveillance of the Remedial Action Contractor (RAC), MK-Ferguson and CWM Federal Environmental Services, Inc., at the processing site in Ambrosia Lake, New Mexico. The requirements and attributes examined during the audit were developed from reviewing working-level procedures developed by the RAC. Objective evidence, comments, and observations were verified based on investigating procedures, documentation, records located at the site, personal interviews, and tours of the site. No findings were identified during this audit. Ten site-specific observations, three good practice observations, and five programmatic observations are presented in this report. The overall conclusion from the surveillance is that the radiological aspects of the Ambrosia Lake, New Mexico, remedial action program are performed adequately. The results of the good practice observations indicate that the site health physics (HP) staff is taking the initiative to address and resolve potential issues, and implement suggestions useful to the UMTRA Project. However, potential exists for improving designated storage areas for general items, and the RAC Project Office should consider resolving site-specific and procedural inconsistencies

  5. Continuous and discrete water-quality data collected at five sites on Lake Houston near Houston, Texas, 2006-08

    Science.gov (United States)

    Beussink, Amy M.; Burnich, Michael R.

    2009-01-01

    Lake Houston, a reservoir impounded in 1954 by the City of Houston, Texas, is a primary source of drinking water for Houston and surrounding areas. The U.S. Geological Survey, in cooperation with the City of Houston, developed a continuous water-quality monitoring network to track daily changes in water quality in the southwestern quadrant of Lake Houston beginning in 2006. Continuous water-quality data (the physiochemical properties water temperature, specific conductance, pH, dissolved oxygen concentration, and turbidity) were collected from Lake Houston to characterize the in-lake processes that affect water quality. Continuous data were collected hourly from mobile, multi-depth monitoring stations developed and constructed by the U.S. Geological Survey. Multi-depth monitoring stations were installed at five sites in three general locations in the southwestern quadrant of the lake. Discrete water-quality data (samples) were collected routinely (once or twice each month) at all sites to characterize the chemical and biological (phytoplankton and bacteria) response to changes in the continuous water-quality properties. Physiochemical properties (the five continuously monitored plus transparency) were measured in the field when samples were collected. In addition to the routine samples, discrete water-quality samples were collected synoptically (one or two times during the study period) at all sites to determine the presence and levels of selected constituents not analyzed in routine samples. Routine samples were measured or analyzed for acid neutralizing capacity; selected major ions and trace elements (calcium, silica, and manganese); nutrients (filtered and total ammonia nitrogen, filtered nitrate plus nitrite nitrogen, total nitrate nitrogen, filtered and total nitrite nitrogen, filtered and total orthophosphate phosphorus, total phosphorus, total nitrogen, total organic carbon); fecal indicator bacteria (total coliform and Escherichia coli); sediment

  6. Summary of the engineering assessment of inactive uranium mill tailings. Vitro site, Salt Lake City, Utah

    International Nuclear Information System (INIS)

    1981-04-01

    This report is a summary of a parent report (issued under separate cover) entitled Engineering Assessment of Inactive Uranium Mill Tailings for Vitro Site, Salt Lake City, Utah. Bacon and Davis Utah Inc. has reevaluated the Vitro site in order to revise the April 1976 assessment of the problems resulting from the existence of radioactive uranium mill tailings at Salt Lake City, Utah. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 1.9 million tons of tailings at the Vitro site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The four alternative actions presented in this engineering assessment range from millsite and off-site decontamination with the addition of 3 m of stabilization cover material (Option 1), to removal of the tailings to remote disposal sites, and decontamination of the tailings site (Options II through IV). Cost estimates for the four options range from about $36,400,000 for stabilization in-place, to about $91,000,000 for disposal at a distance of about 85 mi. Three principal alternatives for the reprocessing of the Vitro tailings were examined: heap leaching; treatment at an existing mill; and reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be about $200/lb by heap leach and $130/lb by conventional plant processes. Spot market price for uranium was $28.00 in November 1980. Therefore, reprocessing the tailings for uranium recovery appears to be economically unattractive at present

  7. 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

  8. Lake Ontario benthic prey fish assessment, 2015

    Science.gov (United States)

    Weidel, Brian C.; Walsh, Maureen; Holden, Jeremy P.; Connerton, Michael J.

    2016-01-01

    Benthic prey fishes are a critical component of the Lake Ontario food web, serving as energy vectors from benthic invertebrates to native and introduced piscivores. Since the late 1970’s, Lake Ontario benthic prey fish status was primarily assessed using bottom trawl observations confined to the lake’s south shore, in waters from 8 – 150 m (26 – 492 ft). In 2015, the Benthic Prey Fish Survey was cooperatively adjusted and expanded to address resource management information needs including lake-wide benthic prey fish population dynamics. Effort increased from 55 bottom trawl sites to 135 trawl sites collected in depths from 8 - 225m (26 – 738 ft). The spatial coverage of sampling was also expanded and occurred in all major lake basins. The resulting distribution of tow depths more closely matched the available lake depth distribution. The additional effort illustrated how previous surveys were underestimating lake-wide Deepwater Sculpin, Myoxocephalus thompsonii, abundance by not sampling in areas of highest density. We also found species richness was greater in the new sampling sites relative to the historic sites with 11 new fish species caught in the new sites including juvenile Round Whitefish, Prosopium cylindraceum, and Mottled sculpin, Cottus bairdii. Species-specific assessments found Slimy Sculpin, Cottus cognatus abundance increased slightly in 2015 relative to 2014, while Deepwater Sculpin and Round Goby, Neogobius melanostomus, dramatically increased in 2015, relative to 2014. The cooperative, lake-wide Benthic Prey Fish Survey expanded our understanding of benthic fish population dynamics and habitat use in Lake Ontario. This survey’s data and interpretations influence international resource management decision making, such as informing the Deepwater Sculpin conservation status and assessing the balance between sport fish consumption and prey fish populations. Additionally a significant Lake Ontario event occurred in May 2015 when a single

  9. Bayesian, maximum parsimony and UPGMA models for inferring the phylogenies of antelopes using mitochondrial markers.

    Science.gov (United States)

    Khan, Haseeb A; Arif, Ibrahim A; Bahkali, Ali H; Al Farhan, Ahmad H; Al Homaidan, Ali A

    2008-10-06

    This investigation was aimed to compare the inference of antelope phylogenies resulting from the 16S rRNA, cytochrome-b (cyt-b) and d-loop segments of mitochondrial DNA using three different computational models including Bayesian (BA), maximum parsimony (MP) and unweighted pair group method with arithmetic mean (UPGMA). The respective nucleotide sequences of three Oryx species (Oryx leucoryx, Oryx dammah and Oryx gazella) and an out-group (Addax nasomaculatus) were aligned and subjected to BA, MP and UPGMA models for comparing the topologies of respective phylogenetic trees. The 16S rRNA region possessed the highest frequency of conserved sequences (97.65%) followed by cyt-b (94.22%) and d-loop (87.29%). There were few transitions (2.35%) and none transversions in 16S rRNA as compared to cyt-b (5.61% transitions and 0.17% transversions) and d-loop (11.57% transitions and 1.14% transversions) while comparing the four taxa. All the three mitochondrial segments clearly differentiated the genus Addax from Oryx using the BA or UPGMA models. The topologies of all the gamma-corrected Bayesian trees were identical irrespective of the marker type. The UPGMA trees resulting from 16S rRNA and d-loop sequences were also identical (Oryx dammah grouped with Oryx leucoryx) to Bayesian trees except that the UPGMA tree based on cyt-b showed a slightly different phylogeny (Oryx dammah grouped with Oryx gazella) with a low bootstrap support. However, the MP model failed to differentiate the genus Addax from Oryx. These findings demonstrate the efficiency and robustness of BA and UPGMA methods for phylogenetic analysis of antelopes using mitochondrial markers.

  10. Water Quality, Cyanobacteria, and Environmental Factors and Their Relations to Microcystin Concentrations for Use in Predictive Models at Ohio Lake Erie and Inland Lake Recreational Sites, 2013-14

    Science.gov (United States)

    Francy, Donna S.; Graham, Jennifer L.; Stelzer, Erin A.; Ecker, Christopher D.; Brady, Amie M. G.; Pam Struffolino,; Loftin, Keith A.

    2015-11-06

    Harmful cyanobacterial “algal” blooms (cyanoHABs) and associated toxins, such as microcystin, are a major water-quality issue for Lake Erie and inland lakes in Ohio. Predicting when and where a bloom may occur is important to protect the public that uses and consumes a water resource; however, predictions are complicated and likely site specific because of the many factors affecting toxin production. Monitoring for a variety of environmental and water-quality factors, for concentrations of cyanobacteria by molecular methods, and for algal pigments such as chlorophyll and phycocyanin by using optical sensors may provide data that can be used to predict the occurrence of cyanoHABs.

  11. Connection of the Late Paleolithic archaeological sites of the Chuya depression with geological evidence of existence of the Late Pleistocene ice-dammed lakes

    Science.gov (United States)

    Agatova, A. R.; Nepop, R. K.

    2017-07-01

    The complexity of the age dating of the Pleistocene ice-dammed paleolakes in the Altai Mountains is a reason why geologists consider the Early Paleolithic archaeological sites as an independent age marker for dating geological objects. However, in order to use these sites for paleogeographic reconstructions, their locations, the character of stratification, and the age of stone artifacts need to be comprehensively studied. We investigate 20 Late Paleolithic archaeological sites discovered in the Chuya depression of the Russian Altai (Altai Mountains) with the aim of their possible use for reconstructions of the period of development of the Kurai-Chuya glacio-limnosystem in the Late Neopleistocene. The results of our investigation show that it is improper to use the Paleolithic archaeological sites for the dating of the existence period and the draining time of ice-dammed lakes of the Chuya Depression in the modern period of their study owing to a lack of quantitative age estimates, a wide age range of possible existence of these sites, possible redeposition of the majority of artifacts, and their surface occurrence. It is established that all stratified sites where cultural layers are expected to be dated in the future lie above the uppermost and well-expressed paleolake level (2100 m a.s.l.). Accordingly, there are no grounds to determine the existence time of shallower paleolakes. Since the whole stone material collected below the level of 2100 m a.s.l. is represented by surface finds, it is problematic to use these artifacts for absolute geochronology. The Late Paleolithic Bigdon and Chechketerek sites are of great interest for paleogeographic reconstructions of ice-dammed lakes. The use of iceberg rafting products as cores is evidence that these sites appeared after the draining of a paleolake (2000 m a.s.l.). At this time, the location of these archaeological sites on the slope of the Chuya Depression allows one to assume the existence of a large lake as deep

  12. Lake Sturgeon, Lake Whitefish, and Walleye egg deposition patterns with response to fish spawning substrate restoration in the St. Clair–Detroit River system

    Science.gov (United States)

    Fischer, Jason L.; Pritt, Jeremy J.; Roseman, Edward; Prichard, Carson G.; Craig, Jaquelyn M.; Kennedy, Gregory W.; Manny, Bruce A.

    2018-01-01

    Egg deposition and use of restored spawning substrates by lithophilic fishes (e.g., Lake Sturgeon Acipenser fulvescens, Lake Whitefish Coregonus clupeaformis, and Walleye Sander vitreus) were assessed throughout the St. Clair–Detroit River system from 2005 to 2016. Bayesian models were used to quantify egg abundance and presence/absence relative to site-specific variables (e.g., depth, velocity, and artificial spawning reef presence) and temperature to evaluate fish use of restored artificial spawning reefs and assess patterns in egg deposition. Lake Whitefish and Walleye egg abundance, probability of detection, and probability of occupancy were assessed with detection-adjusted methods; Lake Sturgeon egg abundance and probability of occurrence were assessed using delta-lognormal methods. The models indicated that the probability of Walleye eggs occupying a site increased with water velocity and that the rate of increase decreased with depth, whereas Lake Whitefish egg occupancy was not correlated with any of the attributes considered. Egg deposition by Lake Whitefish and Walleyes was greater at sites with high water velocities and was lower over artificial spawning reefs. Lake Sturgeon eggs were collected least frequently but were more likely to be collected over artificial spawning reefs and in greater abundances than elsewhere. Detection-adjusted egg abundances were not greater over artificial spawning reefs, indicating that these projects may not directly benefit spawning Walleyes and Lake Whitefish. However, 98% of the Lake Sturgeon eggs observed were collected over artificial spawning reefs, supporting the hypothesis that the reefs provided spawning sites for Lake Sturgeon and could mitigate historic losses of Lake Sturgeon spawning habitat.

  13. Limnology of the Green Lakes Valley: Phytoplankton ecology and dissolved organic matter biogeochemistry at a long-term ecological research site

    Science.gov (United States)

    Miller, Matthew P.; McKnight, Diane M.

    2015-01-01

    Background: Surface waters are the lowest points in the landscape, and therefore serve as excellent integrators and indicators of changes taking place in the surrounding terrestrial and atmospheric environment.Aims: Here we synthesise the findings of limnological studies conducted during the past 15 years in streams and lakes in the Green Lakes Valley, which is part of the Niwot Ridge Long-term Ecological Research (LTER) Site.Methods: The importance of these studies is discussed in the context of aquatic ecosystems as indicators, integrators, and regulators of environmental change. Specifically, investigations into climatic, hydrologic, and nutrient controls on present-day phytoplankton, and historical diatom, community composition in the alpine lake, Green Lake 4, are reviewed. In addition, studies of spatial and temporal patterns in dissolved organic matter (DOM) biogeochemistry and reactive transport modelling that have taken place in the Green Lakes Valley are highlighted.Results and conclusions: The findings of these studies identify specific shifts in algal community composition and DOM biogeochemistry that are indicative of changing environmental conditions and provide a framework for detecting future environmental change in the Green Lakes Valley and in other alpine watersheds. Moreover, the studies summarised here demonstrate the importance of long-term monitoring programmes such as the LTER programme.

  14. Remedial actions at the former Vitro Chemical Company site, South Salt Lake, Salt Lake County, Utah. Volume I. Text. Final Environmental Impact Statement

    International Nuclear Information System (INIS)

    1984-07-01

    This statement evaluates the environmental impacts associated with the cleanup of those residues remaining at the abandoned uranium-mill-tailings site located in South Salt Lake, Utah, and hereinafter called the Vitro site. The site is a 128-acre property owned by the Central Valley Water Reclamation Facility (CVWRP) Board which also operates a sewage treatment plant adjacent to the northern boundaries of the Vitro site. The site contains approximately 2.5 million cubic yards of contaminated residues and soil; the residues were produced by the Vitro Chemical Company of America which processed uranium ore for sale to the US Atomic Energy Commission on the site from 1951 to 1964. This statement evaluates three alternatives for minimizing the public health hazards associated with the Vitro site contaminated materials: (1) no action; (2) stabilization of the contaminated material on the Vitro site; and (3) decontamination of the Vitro site and disposal of the contaminated material at a site located about one mile south of Clive, Utah. Alternative 3 is DOE's preferred alternative. An assessment of the impacts of these three alternatives was made in terms of effects on radiation levels, air quality, soils and mineral resources, surface- and ground-water resources, ecosystems, land use, sound levels, historical and cultural resources, populations and employment, economic structures, and transportation networks

  15. Radionuclide and metal contamination in pit lakes in former U mining sites in Central Asia

    Energy Technology Data Exchange (ETDEWEB)

    Skipperud, L.; Rosseland, B.O.; Heier, L.S.; Salbu, B. [Centre for Environmental Radioactivity - CERAD, Norwegian University of Life Sciences - NMBU (Norway); Stegnar, P. [Josef Stefan Institute (Slovenia); Yunusov, M. [IA Vostokredmet (Tajikistan); Burkitbaev, L.M. [Al-Farabi Kazakh National University (Kazakhstan)

    2014-07-01

    The uranium mining industry in the USSR was established in the late 1940's - early 1950's in the former Soviet Republics of Kazakhstan, Kyrgyzstan, Tajikistan and Uzbekistan as part of the nuclear weapon program. In most countries, uranium mining is considered a hazardous step of nuclear materials production, both in terms of radiation doses and in the number of people affected. Key problems have been associated with the transport of uranium and its daughters in aquatic and terrestrial ecosystems, where radionuclides are transferred from air, water, and soils into plants, fish/animals and finally to man. In this paper, special attention is paid to the assessment of radionuclides and metals in Central Asian Pit Lakes. Field works to Kurday, Kasakhstan, and Taboshar, Tajikistan, Pit Lakes have been performed. In addition to sampling of water, fish, sediments, and vegetation, in situ fractionation of water were achieved. The concentrations of U and associated trace metals were enriched in the Kurday Pit Lake and in the artesian water at the Kurday site (U exceeding the WHO guideline value for drinking water), and decreased downstream from the mining area. Uranium, As, Mo and Ni were predominantly present as mobile low molecular mass species in waters, while a significant proportion of Cr, Mn and Fe were associated with colloids and particles. Due to oxidation of divalent iron in the artesian ground water upon contact with air, Fe served as scavenger for other elements, and peak concentrations of U, Ra-isotopes, As and Mn were seen. The U concentrations in water from Taboshar Pit Lake (2.0 mg U/L) were higher than waters collected in other areas in Tajikistan. The Pit Lake and the stream water from the tailing mountain were also characterized by elevated concentrations of As, Mo, Mn and Fe, exceeding the WHO recommended values for drinking water. Uranium, As, Mo and Ni were present as low molecular mass species in the waters, and are therefore considered

  16. Geochemical investigation of UMTRAP designated site at Salt Lake City, Utah

    International Nuclear Information System (INIS)

    Markos, G.; Bush, K.J.

    1983-09-01

    This report is the result of a geochemical investigation of the former uranium mill and tailings site at Salt Lake City, Utah. This is one in a series of site specific geochemical investigations performed on the inactive uranium mill tailings included in the Uranium Mill Tailings Remedial Action Project. The objectives of the investigation are to characterize the geochemistry, to determine the contaminant distribution resulting from the former milling activities and tailings, and to infer chemical pathways and transport mechanisms from the contaminant distribution. The results will be used to model contaminant migration and to develop criteria for long-term containment media such as a cover system which is impermeable to contaminant migration. This report assumes a familiarity with the hydrologic conditions of the site and the geochemical concepts underlying the investigation. The results reported are based on a one-time sampling of waters and solid material from the background, the area adjacent to the site, and the site. The solid samples were water extracted to remove easily soluble salts and acid extracted to remove carbonates and hydroxides. The water extracts and solid samples were anlyzed for the major and trace elements. The report includes the methods of sampling, sample processing, analysis, and data interpretation. Four major conclusions are: (1) sediments in the ditches and creeks adjacent to the site contain tailings, however, the waters were generally not contaminated; (2) tailings are mixed with the soils within a meter below the tailings in some locations, however, water-soluble contaminants decrease to below background levels within 30 cm below the tailings; (3) there has not been significant acid seepage into the soils below the tailings; and (4) salt crusts on the tailings contain trace elements, with the elements that form chloride complexes having the greatest accumulation

  17. Changes in the dreissenid community in the lower Great Lakes with emphasis on southern Lake Ontario

    Science.gov (United States)

    Mills, Edward L.; Chrisman, Jana R.; Baldwin, Brad; Owens, Randall W.; O'Gorman, Robert; Howell, Todd; Roseman, Edward F.; Raths, Melinda K.

    1999-01-01

    A field study was conducted in the lower Great Lakes to assess changes in spatial distribution and population structure of dreissenid mussel populations. More specifically, the westward range expansion of quagga mussel into western Lake Erie and toward Lake Huron was investigated and the shell size, density, and biomass of zebra and quagga mussel with depth in southern Lake Ontario in 1992 and 1995 were compared. In Lake Erie, quagga mussel dominated the dreissenid community in the eastern basin and zebra mussel dominated in the western basin. In southern Lake Ontario, an east to west gradient was observed with the quagga mussel dominant at western sites and zebra mussel dominant at eastern locations. Mean shell size of quagga mussel was generally larger than that of zebra mussel except in western Lake Erie and one site in eastern Lake Erie. Although mean shell size and our index of numbers and biomass of both dreissenid species increased sharply in southern Lake Ontario between 1992 and 1995, the increase in density and biomass was much greater for quagga mussels over the 3-year period. In 1995, zebra mussels were most abundant at 15 to 25 m whereas the highest numbers and biomass of quagga mussel were at 35 to 45 m. The quagga mussel is now the most abundant dreissenid in areas of southern Lake Ontario where the zebra mussel was once the most abundant dreissenid; this trend parallels that observed for dreissenid populations in the Dneiper River basin in the Ukraine.

  18. Onondaga Lake: A Forsaken Superfund Site, or a Sampling Playground for Environmental Geochemistry Classes?

    Science.gov (United States)

    Karmosky, C. C.; Harpp, K. S.

    2004-05-01

    Onondaga Lake, in Syracuse, NY, is described by the EPA as one of the most polluted lakes in the US. High levels of heavy metal and semi-volatile organic contamination provide an excellent case study that serves as the cornerstone for an environmental geochemistry course at Colgate University. Our course is designed to teach students basic environmental analysis skills including experimental design, sample preparation, analytical instrumentation operation, data processing and statistical analysis, and preparation of a collaborative scientific paper. Participating students generally have some background in environmental geology, but rarely more than one semester of chemistry. The Onondaga Lake project is the focus of the course for approximately half the semester. At the outset of the project, students are presented with a driving question that is answered through a series of guided field and lab investigations, such as an assessment of the environmental consequences of a proposed marina along the lakefront. The students' first task is to delve into the lake's environmental history, including identification of contaminants, location of point and non-point pollution sources, and clean-up efforts. Students then participate in 2 field trips to the site. First, students learn the geography of the lake system, collect sediment and water samples, and observe mitigation efforts at the wastewater treatment plant. The second trip is 2-3 weeks later, after students have assessed further sampling needs. Identification and quantification of organic compounds are accomplished by GC-MS, and heavy metal contents are determined by ICP-MS. Students compile their results, perform statistical analyses, and collaboratively draw their conclusions regarding the impact of the proposed project. The final product is a single report written by the entire class, an exercise in organization, cooperation, and planning that is usually the most challenging, but ultimately the most rewarding

  19. Using lead isotopes and trace element records from two contrasting Lake Tanganyika sediment cores to assess watershed – Lake exchange

    Science.gov (United States)

    Odigie, Kingsley; Cohen, A.D.; Swarzenski, Peter W.; Flegal, R

    2014-01-01

    Lead isotopic and trace element records of two contrasting sediment cores were examined to reconstruct historic, industrial contaminant inputs to Lake Tanganyika, Africa. Observed fluxes of Co, Cu, Mn, Ni, Pb, and Zn in age-dated sediments collected from the lake varied both spatially and temporally over the past two to four centuries. The fluxes of trace elements were lower (up to 10-fold) at a mid-lake site (MC1) than at a nearshore site (LT-98-58), which is directly downstream from the Kahama and Nyasanga River watersheds and adjacent to the relatively pristine Gombe Stream National Park. Trace element fluxes at that nearshore site did not measurably change over the last two centuries (1815–1998), while the distal, mid-lake site exhibited substantial changes in the fluxes of trace elements – likely caused by changes in land use – over that period. For example, the flux of Pb increased by ∼300% from 1871 to 1991. That apparent accelerated weathering and detrital mobilization of lithogenic trace elements was further evidenced by (i) positive correlations (r = 0.77–0.99, p factors (EF operations within the lake’s watershed over the past century. The data also indicate that the mid-lake site is a much more sensitive and useful recorder of environmental changes than the nearshore site. Furthermore, the lead isotopic compositions of sediment at the sites differed spatially, indicating that the Pb (and other trace elements by association) originated from different natural sources at the two locations.

  20. Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 408: Bomblet Target Area, Tonopah Test Range, Nevada

    International Nuclear Information System (INIS)

    NSTec Environmental Management

    2006-01-01

    This Streamlined Approach for Environmental Restoration Plan provides the details for the closure of Corrective Action Unit (CAU) 408, Bomblet Target Area. CAU 408 is located at the Tonopah Test Range and is currently listed in Appendix III of the Federal Facility Agreement and Consent Order of 1996. One Corrective Action Site (CAS) is included in CAU 408: (lg b ullet) CAS TA-55-002-TAB2, Bomblet Target Areas Based on historical documentation, personnel interviews, process knowledge, site visits, aerial photography, multispectral data, preliminary geophysical surveys, and the results of data quality objectives process (Section 3.0), clean closure will be implemented for CAU 408. CAU 408 closure activities will consist of identification and clearance of bomblet target areas, identification and removal of depleted uranium (DU) fragments on South Antelope Lake, and collection of verification samples. Any soil containing contaminants at concentrations above the action levels will be excavated and transported to an appropriate disposal facility. Based on existing information, contaminants of potential concern at CAU 408 include explosives. In addition, at South Antelope Lake, bomblets containing DU were tested. None of these contaminants is expected to be present in the soil at concentrations above the action levels; however, this will be determined by radiological surveys and verification sample results. The corrective action investigation and closure activities have been planned to include data collection and hold points throughout the process. Hold points are designed to allow decision makers to review the existing data and decide which of the available options are most suitable. Hold points include the review of radiological, geophysical, and analytical data and field observations

  1. Forsmark site investigation. Investigation of marine and lacustrine sediment in lakes. Field data 2003

    Energy Technology Data Exchange (ETDEWEB)

    Hedenstroem, Anna [SGU, Uppsala (Sweden)

    2003-04-01

    The aim of this activity is to describe the aerial and stratigraphical distribution of marine and lacustrine sediment i.e. sediment overlaying the glacial till and/or bedrock surface, in lakes in the Forsmark area. The investigation is carried out within areas where mapping of unconsolidated Quaternary deposits is presently carried out. Since small and shallow lakes cover a large part of the region, this work will give important information on the distribution and stratigraphy of sedimentary deposits not included in the regular mapping of unconsolidated Quaternary deposits within the site investigation programme. Samples were also collected for laboratory analyses of grain size distribution, mineralogical composition as well as the total content of C, N and S and calcium carbonate. The analyses will be carried out on selected samples of representative sedimentary units in order to characterise the chemical and physical properties of the unconsolidated deposits. The analytical data will be useful for the hydrogeological modelling and for models of the Quaternary evolution of the area. The mineralogical analyses of clay may provide information on the origin of the clay particles. One stratigraphic sequence from Lake Eckarfjaerden will be stored for later analyses, e.g. pollen analysis. This report includes field data from spring 2003. Together, the field data and the forthcoming results from the laboratory analyses will form the basis for construction of stratigraphical profiles to be presented in a following report in the fall 2003.

  2. Forsmark site investigation. Investigation of marine and lacustrine sediment in lakes. Field data 2003

    International Nuclear Information System (INIS)

    Hedenstroem, Anna

    2003-04-01

    The aim of this activity is to describe the aerial and stratigraphical distribution of marine and lacustrine sediment i.e. sediment overlaying the glacial till and/or bedrock surface, in lakes in the Forsmark area. The investigation is carried out within areas where mapping of unconsolidated Quaternary deposits is presently carried out. Since small and shallow lakes cover a large part of the region, this work will give important information on the distribution and stratigraphy of sedimentary deposits not included in the regular mapping of unconsolidated Quaternary deposits within the site investigation programme. Samples were also collected for laboratory analyses of grain size distribution, mineralogical composition as well as the total content of C, N and S and calcium carbonate. The analyses will be carried out on selected samples of representative sedimentary units in order to characterise the chemical and physical properties of the unconsolidated deposits. The analytical data will be useful for the hydrogeological modelling and for models of the Quaternary evolution of the area. The mineralogical analyses of clay may provide information on the origin of the clay particles. One stratigraphic sequence from Lake Eckarfjaerden will be stored for later analyses, e.g. pollen analysis. This report includes field data from spring 2003. Together, the field data and the forthcoming results from the laboratory analyses will form the basis for construction of stratigraphical profiles to be presented in a following report in the fall 2003

  3. Malaria vectors in Lake Victoria and adjacent habitats in western Kenya.

    Directory of Open Access Journals (Sweden)

    Noboru Minakawa

    Full Text Available The prevalence of malaria among the residents of the Lake Victoria basin remains high. The environment associated with the lake may maintain a high number of malaria vectors. Lake habitats including water hyacinths have been suspected to be the source of vectors. This study investigated whether malaria vectors breed in the lake habitats and adjacent backwater pools. Anopheline larvae were collected within the littoral zone of the lake and adjacent pools located along approximately 24.3 km of the lakeshore in western Kenya, and their breeding sites characterized. Three primary vector species, Anopheles arabiensis, Anopheles gambiae s.s. and Anopheles funestus s.s., and three potential vectors, were found in the lake habitats. Unexpectedly, An. arabiensis was the most dominant vector species in the lake sampling sites. Its habitats were uncovered or covered with short grass. A potential secondary malaria vector, Anopheles rivulorum, dominated the water hyacinths in the lake. Most breeding sites in the lake were limited to areas that were surrounded by tall emergent plants, including trees, and those not exposed to waves. Nearly half of adjacent habitats were lagoons that were separated from the lake by sand bars. Lagoons contained a variety of microhabitats. Anopheles arabiensis dominated open habitats, whereas An. funestus s.s. was found mainly in vegetated habitats in lagoons. The current study confirmed that several breeding sites are associated with Lake Victoria. Given that Lake Victoria is the second largest lake in the world, the lake related habitats must be extensive; therefore, making targeted vector control difficult. Further exploration is necessary to estimate the effects of lake associated habitats on malaria transmission so as to inform a rational decision-making process for vector control.

  4. Cordova Lake dam hydroelectric generating station case study

    International Nuclear Information System (INIS)

    Kerr, D.; Huxley, J.

    1993-01-01

    The Ontario Ministry of Natural Resources released a Crown owned site to the private water power industry as part of the small hydro site release program initiated by the Ontario Government in the mid 1980's. The Cordova Lake Dam Hydroelectric Generating Station, built on this site, has been in operation since the first week of October, 1992. Since that time, the plant has been operating with less than 1 % down time and has generated over 2,400 MWh of electricity. Algonquin Power Systems is responsible for the management and operations of the plant which includes full time monitoring from the company's Mississauga office and a part time employee at Cordova Lake. Cordova Lake Dam is located on the Crowe River at the outlet of Cordova Lake, approximately 125 kilometers east of Toronto, Ontario. The total cost of the Cordova Lake Dam project was $1.6 million. Algonquin Power contributed 20% equity to the project. Algonquin Power was also responsible for all engineering and geotechnical work and for completing the construction and equipment contracts. 1 tab., 2 figs

  5. Development of a zoning-based environmental-ecological-coupled model for lakes to assess lake restoration effect

    Science.gov (United States)

    Xu, Mengjia; Zou, Changxin; Zhao, Yanwei

    2017-04-01

    Environmental/ecological models are widely used for lake management as they provide a means to understand physical, chemical and biological processes in highly complex ecosystems. Most research focused on the development of environmental (water quality) and ecological models, separately. Limited studies were developed to couple the two models, and in these limited coupled models, a lake was regarded as a whole for analysis (i.e., considering the lake to be one well-mixed box), which was appropriate for small-scale lakes and was not sufficient to capture spatial variations within middle-scale or large-scale lakes. This paper seeks to establish a zoning-based environmental-ecological-coupled model for a lake. The Baiyangdian Lake, the largest freshwater lake in Northern China, was adopted as the study case. The coupled lake models including a hydrodynamics and water quality model established by MIKE21 and a compartmental ecological model used STELLA software have been established for middle-sized Baiyangdian Lake to realize the simulation of spatial variations of ecological conditions. On the basis of the flow field distribution results generated by MIKE21 hydrodynamics model, four water area zones were used as an example for compartmental ecological model calibration and validation. The results revealed that the developed coupled lake models can reasonably reflected the changes of the key state variables although there remain some state variables that are not well represented by the model due to the low quality of field monitoring data. Monitoring sites in a compartment may not be representative of the water quality and ecological conditions in the entire compartment even though that is the intention of compartment-based model design. There was only one ecological observation from a single monitoring site for some periods. This single-measurement issue may cause large discrepancies particularly when sampled site is not representative of the whole compartment. The

  6. Mercury concentrations of fish in Southern Indian Lake and Issett Lake, Manitoba 1975-88: The effect of lake impoundment and Churchill River diversion

    International Nuclear Information System (INIS)

    Strange, N.E.; Bodaly, R.A.; Fudge, R.J.P.

    1991-01-01

    Southern Indian and Issett Lakes in northern Manitoba were flooded in 1976 as part of Manitoba Hydro's Churchill River diversion project. Fish were collected from 1975 to 1988 from five regional sites on the lakes to examine the effects of impoundment and river diversion on muscle mercury concentrations. Raw data for individual fish caught in 1987 and 1988 are presented, along with means and analyses calculated over the entire 1975-1988 study period. Mercury concentrations in whitefish, pike, and walleye increased significantly after impoundment. Whitefish mercury levels peaked in 1978 and have since declined to near pre-flooding levels. Northern pike and walleye mercury levels were much higher than for whitefish. Pike mercury concentrations showed no indication of declining after 12 years of impoundment, but walleye mercury levels at 2 of the 5 Southern Indian Lake sites declined from maximum recorded levels. Significant variability in fish mercury concentrations was noted both from year to year and among the sites. It is suggested that site-to-site variations are due to varying conditions in the reservoir which stimulate mercury methylation. Since there appears to be an ongoing long-term source of mercury and organic material from the eroding shorelines, pike and walleye mercury concentrations are expected to remain high for many years. 25 refs., 7 figs., 20 tabs

  7. Evaluation of Brucella abortus strain RB51 and strain 19 in pronghorn antelope

    Science.gov (United States)

    Elzer, P.H.; Smith, J.; Roffe, T.; Kreeger, T.; Edwards, J.; Davis, D.

    2002-01-01

    Free-roaming elk and bison in the Greater Yellowstone Area remain the only wildlife reservoirs for Brucella abortus in the United States, and the large number of animals and a lack of holding facilities make it unreasonable to individually vaccinate each animal. Therefore, oral delivery is being proposed as a possible option to vaccinate these wild ungulates. One of the main problems associated with oral vaccination is the potential exposure of nontarget species to the vaccines. The purpose of this study was to determine the effects of two Brucella vaccines, strain 19 (S19) and the rough strain RB51 (SRB51), in pregnant pronghorn antelope. We conclude that S19 and SRB51 rarely colonize maternal and fetal tissues of pregnant pronghorn and were not associated with fetal death. Oral delivery of either vaccine at this dose appears to be nonhazardous to pregnant pronghorn.

  8. 75 FR 34448 - Proposed CERCLA Administrative Cost Recovery Settlement; Great Lakes Container Corporation...

    Science.gov (United States)

    2010-06-17

    ... Settlement; Great Lakes Container Corporation Superfund Site, Coventry Rhode Island AGENCY: Environmental... and future response costs concerning the Great Lakes Container Corporation Superfund Site, located in...), Boston, MA 02109-3912, (617) 918-1216. Comments should reference the Great Lakes Container Corporation...

  9. Visual observations of historical lake trout spawning grounds in western Lake Huron

    Science.gov (United States)

    Nester, Robert T.; Poe, Thomas P.

    1987-01-01

    Direct underwater video observations were made of the bottom substrates at 12 spawning grounds formerly used by lake trout Salvelinus namaycush in western Lake Huron to evaluate their present suitability for successful reproduction by lake trout. Nine locations examined north of Saginaw Bay in the northwestern end of the lake are thought to provide the best spawning habitat. The substrate at these sites consisted of angular rough cobble and rubble with relatively deep interstitial spaces (a?Y 0.5 m), small amounts of fine sediments, and little or no periphytic growth. Conditions at the three other sampling locations south of Saginaw Bay seemed much less suitable for successful reproduction based on the reduced area of high-quality substrate, shallow interstitial spaces, high infiltration of fine sediments, and greater periphytic growth.

  10. Sedimentological, mineralogical, and geochemical results from surface sediments and the sediment record from Site 2 of the ICDP drilling project at Lake Towuti, Indonesia

    Science.gov (United States)

    Hasberg, A. K.; Melles, M.; Wennrich, V.; Vogel, H.; Just, J.; Russell, J. M.; Bijaksana, S.; Morlock, M.; Opitz, S.

    2017-12-01

    More than 1000 m of sediment core were recovered in spring 2015 from three different drill sites in tropical Lake Towuti (2.5°S, 121°E), Indonesia, during the Towuti Drilling Project (TDP) of the International Continental Scientific Drilling Program (ICDP). Furthermore, a set of 84 lake surface sediment samples, distributed over the entire lake, was collected in order to better understand modern sedimentary processes. The surface samples were investigated for physical, chemical, mineralogical, and biological properties at the University of Cologne (UoC), Germany. On the sediment cores macro- and microscopical lithological descriptions, line-scan imaging, logging of physical properties (MSCL), and subsampling was conducted at the National Lacustrine Core Facility of the University of Minnesota, USA, in November 2015 and January 2016. Afterwards, the archive core halves and 672 subsamples of TDP Site 2 were shipped to the UoC for X-Ray Fluorescence (XRF) scanning and sedimentological, geochemical, and mineralogical analyses, respectively, supplemented by visible to near-infrared spectroscopy (VNIR) at Brown University, USA. The data from the surface samples evidence that allochthonous sedimentation in Lake Towuti today is dominated by fluvial supply from five distinguishable source areas: (i) the Mahalona River to the north, which drains lakes Mahalona and Matano, (ii) inlets around the village of Timampu to the northwest, (iii) the Loeha River to the east, (iv) the Lengke River to the south, and (v) the Lemo-Lemo River to the northeast of Lake Towuti. Of these, source areas (ii) and (iii) as well as (iv) and (v) have similar geochemical compositions, respectively. In addition, the lake sedimentation is significantly influenced by gravitational sediment supply from steep slopes as well as lake-internal gravitational and density-driven processes. The uppermost 41 m of sediment core 2A consist of pelagic sediments (totaling 11 m) and event layers from mass movement

  11. Conceptual modeling framework to support development of site-specific selenium criteria for Lake Koocanusa, Montana, U.S.A., and British Columbia, Canada

    Science.gov (United States)

    Jenni, Karen E.; Naftz, David L.; Presser, Theresa S.

    2017-10-16

    The U.S. Geological Survey, working with the Montana Department of Environmental Quality and the British Columbia Ministry of the Environment and Climate Change Strategy, has developed a conceptual modeling framework that can be used to provide structured and scientifically based input to the Lake Koocanusa Monitoring and Research Working Group as they consider potential site-specific selenium criteria for Lake Koocanusa, a transboundary reservoir located in Montana and British Columbia. This report describes that modeling framework, provides an example of how it can be applied, and outlines possible next steps for implementing the framework.

  12. Potential reference mires and lakes ecosystems for biosphere assessment of Olkiluoto site

    International Nuclear Information System (INIS)

    Haapanen, R.; Aro, L.; Kirkkala, T.; Paloheimo, A.; Koivunen, S.; Lahdenperae, A.-M.

    2010-10-01

    New lakes and mires will develop in the sea area now surrounding Olkiluoto Island due to the postglacial land uplift. The properties of these objects can be forecast using data from existing lakes and mires. There are, however, no such objects on the present Olkiluoto Island. This Working Report presents a project, initiated in 2007, where lakes and mires at different successional stages, suitable as reference objects for the future ones, were searched. The task included delineation of the study area, based on e.g. geological and climatological factors, and development of the selection criteria. As background, development history and properties of present lakes and mires in the study area are described in this report. For this and forthcoming projects, several GIS data sets were acquired. With help of these data, literature and environmental databases, 33 mires and 27 lakes were selected. These were considered to be the best available analogues for the future objects around Olkiluoto Island. The characteristics of these objects are presented briefly; more detailed information is found in the literature and databases. (orig.)

  13. Stress transfer by the 1988-1989 M=5.3 and 5.4 Lake Elsman foreshocks to the Loma Prieta fault: Unclamping at the site of peak mainshock slip

    Science.gov (United States)

    Perfettini, H.; Stein, R.S.; Simpson, R.; Cocco, M.

    1999-01-01

    We study the stress transferred by the June 27, 1988, M=5.3 and August 8, 1989, M=5.4 Lake Elsman earthquakes, the largest events to strike within 15 km of the future Loma Prieta rupture zone during 74 years before the 1989 M=6.9 Loma Prieta earthquake. We find that the first Lake Elsman event brought the rupture plane of the second event 0.3-1.6 bars (0.03-0.16 MPa) closer to Coulomb failure but that the Lake Elsman events did not bring the future Loma Prieta hypocentral zone closer to failure. Instead, the Lake Elsman earthquakes are calculated to have reduced the normal stress on (or "undamped") the Loma Prieta rupture surface by 0.5-1.0 bar (0.05-0.10 MPa) at the site where the greatest slip subsequently occurred in the Loma Prieta earthquake. This association between the sites of peak unclamping and slip suggests that the Lake Elsman events did indeed influence the Loma Prieta rupture process. Unclamping the fault would have locally lowered the resistance to sliding. Such an effect could have been enhanced if the lowered normal stress permitted fluid infusion into the undamped part of the fault. Although less well recorded, the ML=5.0 1964 and ML=5.3 1967 Corralitos events struck within 10 km of the southwest end of the future Loma Prieta rupture. No similar relationship between the normal stress change and subsequent Loma Prieta slip is observed, although the high-slip patch southwest of the Loma Prieta epicenter corresponds roughly to the site of calculated Coulomb stress increase for a low coefficient of friction. The Lake Elsman-Loma Prieta result is similar to that for the 1987 M=6.2 Elmore Ranch and M=6.7 Superstition Hills earthquakes, suggesting that foreshocks might influence the distribution of mainshock slip rather than the site of mainshock nucleation. Copyright 1999 by the American Geophysical Union.

  14. An overview of the recent palaeolimnology of selected lakes in the Romanian Carpathians

    Directory of Open Access Journals (Sweden)

    Simon M. HUTCHINSON

    2011-06-01

    Full Text Available Lakesediments can act as sensitive monitors of environmental change and human impacts. The Romanian Carpathians hold a significant number of glacial lakes and transverse a region of considerable environmental concerns, but relatively sparse environmental data and little recent lake sediment based research. Findings from selected lakes in two of the highest sections of these mountains inRomaniaare presented. In addition the palaeolimnological record held in the surficial sediments of other lower elevations sites in theEastern Carpathiansis also discussed. These sites are situated in contrasting sites comprising a volcanic crater lake (Lacul Sfânta Ana,HarghitaMountains and a lake dammed by land sliding (Lacul Iezer-Feredeu, Obcina Feredeului. 

  15. Engineering assessment of inactive uranium mill tailings. Vitro site, Salt Lake City, Utah

    International Nuclear Information System (INIS)

    1981-04-01

    Ford, Bacon and Davis Utah Inc. has reevaluated the Vitro site in order to revise the April 1976 assessment of the problems resulting from the existence of radioactive uranium mill tailings at Salt Lake City, Utah. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 1.9 million tons of tailings at the Vitro site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The four alternative actions presented in this engineering assessment range from millsite and off-site decontamination with the addition of 3 m of stabilization cover material (Option I), to removal of the tailings to remote disposal sites, and decontamination of the tailings site (Options II through IV). Cost estimates for the four options range from about $36,400,000 for stabilization in-place, to about $91,000,000 for disposal at a distance of about 85 mi. Three principal alternatives for the reprocessing of the Vitro tailings were examined: heap leaching; treatment at an existing mill; and reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be about $200/lb by heap leach and $130/lb by conventional plant processes. Spot market price for uranium was $28.00 in November 1980. Therefore, reprocessing the tailings for uranium recovery appears to be economically unattractive at present

  16. 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

  17. Modelling of soil depth and lake sediments. An application of the GeoEditor at the Forsmark site

    International Nuclear Information System (INIS)

    Vikstroem, Maria

    2005-02-01

    This report aims at describing the modelled soil depth according to three layers with different hydrogeological properties at the Forsmark site, based on available data from boreholes, observation points, seismic data and radar profiles. For the lakes in the area, the sediment has been modelled according to six layers of the most common deposits in the area. The peat layer at Stenroesmossen has also been visualized. The program used in the modelling of soil depths is the GeoEditor, which is an ArcView3.3-extension. The input data used in the model consist of 1,532 points based on seismic measurements, 31 profiles of interpreted ground penetrating radar data, 119 boreholes and 472 observation points. The western and south eastern part of the area has a low data density. In the southern parts the data density with respect to estimated bedrock elevation is low. Observation points in this area are generally not very deep and do not describe the actual bedrock elevation. They do, however, describe the minimum soil depth at each location. A detailed topographical DEM, bathymetry and map of Quaternary deposits were also used. The model is based on a three-layer-principle where each layer is assumed to have similar hydrological characteristics. The uppermost layer, Z1, is characterized by the impact from surface processes, roots and biological activity. The bottom layer, Z3, is characterized by contact with the bedrock. The middle layer, Z2, is assumed to have different hydraulic qualities than Z1 and Z3. The lake sediments have been modelled according to six classes of typical deposits. The modelled soil depths show a relatively high bedrock elevation and thus small total soil depth in the major part of the area. The median soil depth has been calculated to 1.9 m, based on model results in areas with higher data density. The maximum modelled soil depth is about 13 m, just north of Lake Stocksjoen. Generally, the sediment layers in the lakes of the area consists of a

  18. Past climate changes and permafrost depth at the Lake El'gygytgyn site: implications from data and thermal modeling

    Directory of Open Access Journals (Sweden)

    D. Mottaghy

    2013-01-01

    Full Text Available This study focuses on the temperature field observed in boreholes drilled as part of interdisciplinary scientific campaign targeting the El'gygytgyn Crater Lake in NE Russia. Temperature data are available from two sites: the lake borehole 5011-1 located near the center of the lake reaching 400 m depth, and the land borehole 5011-3 at the rim of the lake, with a depth of 140 m. Constraints on permafrost depth and past climate changes are derived from numerical simulation of the thermal regime associated with the lake-related talik structure. The thermal properties of the subsurface needed for these simulations are based on laboratory measurements of representative cores from the quaternary sediments and the underlying impact-affected rock, complemented by further information from geophysical logs and data from published literature. The temperature observations in the lake borehole 5011-1 are dominated by thermal perturbations related to the drilling process, and thus only give reliable values for the lowermost value in the borehole. Undisturbed temperature data recorded over more than two years are available in the 140 m deep land-based borehole 5011-3. The analysis of these observations allows determination of not only the recent mean annual ground surface temperature, but also the ground surface temperature history, though with large uncertainties. Although the depth of this borehole is by far too insufficient for a complete reconstruction of past temperatures back to the Last Glacial Maximum, it still affects the thermal regime, and thus permafrost depth. This effect is constrained by numerical modeling: assuming that the lake borehole observations are hardly influenced by the past changes in surface air temperature, an estimate of steady-state conditions is possible, leading to a meaningful value of 14 ± 5 K for the post-glacial warming. The strong curvature of the temperature data in shallower depths around 60 m can be explained by a

  19. Hydrology and water quality of East Lake Tohopekaliga, Osceola County, Florida

    Science.gov (United States)

    Schiffer, Donna M.

    1987-01-01

    East Lake Tohopekaliga, one of the major lakes in central Florida, is located in the upper Kissimmee River basin in north-east Osceola County. It is one of numerous lakes in the upper basin used for flood control, in addition to recreation and some irrigation of surrounding pasture. This report is the fourth in a series of lake reconnaissance studies in the Kissimmee River basin prepared in cooperation with the South Florida Water Management District. The purpose of the report is to provide government agencies and the public with a brief summary of the lake 's hydrology and water quality. Site information is given and includes map number, site name, location, and type of data available (specific conductivity, pH, alkalinity, turbidity, color, dissolved oxygen, hardness, dissolved chlorides, dissolved sodium, dissolved calcium, dissolved magnesium, dissolved potassium, nitrogen, ammonia, nitrates, carbon and phosphorus). The U.S. Geological Survey (USGS) maintained a lake stage gaging station on East Lake Tohopekaliga from 1942 to 1968. The South Florida Water Management District has recorded lake stage since 1963. Periodic water quality samples have been collected from the lake by the South Florida Water Management District and USGS. Water quality and discharge data have been collected for one major tributary to the lake, Boggy Creek. Although few groundwater data are available for the study area, results of previous studies of the groundwater resources of Osceola County are included in this report. To supplement the water quality data for East Lake Tohopekaliga, water samples were collected at selected sites in November 1982 (dry season) and in August 1983 (rainy season). Samples were taken at inflow points, and in the lake, and vertical profiles of dissolved oxygen and temperature were measured in the lake. A water budget from an EPA report on the lake is also included. (Lantz-PTT)

  20. Lithosphere-biosphere interaction at a shallow-sea hydrothermal vent site; Hot Lake, Panarea, Italy

    Science.gov (United States)

    Huang, Chia-I.; Amann, Rudolf; Amend, Jan P.; Bach, Wolfgang; Brunner, Benjamin; Meyerdierks, Anke; Price, Roy E.; Schubotz, Florence; Summons, Roger; Wenzhöfer, Frank

    2010-05-01

    Deep-Sea hydrothermal systems are unique habitats for microbial life with primary production based on chemosynthesis and are considered to be windows to the subsurface biosphere. It is often overlooked, however, that their far more accessible shallow-sea counterparts are also valuable targets to study the effects of hydrothermal activity on geology, seawater chemistry and finally, on microbial life. Such an area of shallow marine hydrothermal venting is observed approximately 2.5 km east of Panarea Island (Sicily, Italy). This system is characterized by fluid temperatures of up to 135° C, gas emissions dominated by CO2 and precipitation of elemental sulfur on the seafloor. In an interdisciplinary project to investigate the influence of geofuels on marine microbiota, sediment cores and pore fluids were sampled for geological and geochemical analyses. An attempt was made to link these geochemical data with a characterization of the microbial community. One of the investigated sites (Lago Caldo, Hot Lake) is an oval-shaped (~10 by 6 meters) shallow (~2.5 m deep) depression covered by elemental sulfur. The sediments in this depression are strongly affected by hydrothermal activity: the pH of pore fluids is in a range between 5 and 6; the salinity is approximately two times higher than seawater. In situ temperatures of 36° C and 74° C (10 cm sediment depth) at two different locations within Hot Lake indicate variability in hydrothermal flux. The sediment surface layer is anoxic, and with increasing depth from the sediment-water interface, sulfate concentrations decrease from ~30 mM to less than 10 mM, whereas sulfide concentrations increase from less than 50 μm to ~1000 μm at 25 cm sediment depth, thus suggesting a higher potential for energy gain based on sulfur disequilibrium. As indicated by the variability in the sediment temperatures at 10 cm, fluid fluxes and mixing with seawater is not found to be uniform at Hot Lake. This is reflected in variability of the

  1. Water quality assessment in a shallow lake used for tourism

    Directory of Open Access Journals (Sweden)

    Dembowska Ewa A.

    2015-12-01

    Full Text Available The routine evaluation of water quality is limited to lakes with the largest area. In Poland, only lakes with an area exceeding 50 hectares are monitored by the State Environmental Monitoring System. For many local communities, however, small lakes are more important. This applies mainly to areas with a small number of lakes, where even the smallest lakes are used for various purposes. This paper presents the results of phytoplankton analysis in a small and shallow lake used for recreation. The study was conducted at three sites located in different parts of the lake. A total of 122 algae taxa were identified in the phytoplankton, mainly diatoms and green algae. The most constant taxa in the lake were: Stephanodiscus hantzschii, Desmodesmus communis, Pediastrum tetras and Crucigenia tetrapedia. The average phytoplankton biomass was 37 mg l−1. The maximum biomass, almost 140 mg dm−3, was recorded in late July at the site located near the beach. At that time, there was a massive cyanobacterial bloom composed of Microcystis wesenbergii and Aphanizomenon issatschenkoi. Based on these studies, the lake should be classified as hypertrophic with bad ecological status. This lake should not be used for recreational purposes in the current state.

  2. Origin of the Livelihood Dilemma for Local Fisherman in Poyang Lake Wetland: a Ramsar Site in China

    Science.gov (United States)

    Xie, Dongming; Zhou, Guohong; Zhou, Yangming; Chen, Yayun; Jia, Junsong

    2018-01-01

    Poyang Lake is one of the first Ramsar sites in China; it has plenty of natural resources that support the survival of local residents. However, local fisherman have encountered a livelihood dilemma, as natural resources have declined, obviously because of the change in the ecological environment and anthropic disturbance. We seek to explain what lead to livelihood dilemma to the local fishermen, so semi-structured interviews, questionnaire surveys, Geographic information system (GIS), Remote sensing (RS), Global position system (GPS), and department data were used to analyze the internal and external factors for these dilemmas. The results explained the external factors including the exhaustion of natural resources, the drying up of wetlands, landscape fragmentation, water contamination, and disturbance through anthropic behavior; the internal factors included the ageing of fishermen, poor cultural quality, conservative ideas, and unreasonable fishing practices. Eco-compensation, industry transformation, and capacity innovation may help to resolve livelihood dilemmas for the local fisherman of the Poyang Lake wetlands.

  3. A WILDLIFE MONITORING SYSTEM BASED ON TIANDITU AND BEIDOU: IN CASE OF THE TIBETAN ANTELOPE

    Directory of Open Access Journals (Sweden)

    H. Zhang

    2016-06-01

    Full Text Available Positioning and tracking wildlife is already being an effective way to collect biological information for research and species of wildlife protection. The common technologies of tracking wildlife are divided into several categories, such as radio tracking technology, GPS tracking system, radio frequency identification technology (RFID, and SIM card based technology. Some positive results achieved from these technologies, but there are some problems in location accuracy, price of the system. Taking the case of the protection of the Tibetan antelope, this paper introduces a wildlife monitoring system based on Tianditu and Beidou navigation satellite system. The system consists of two parts: real-time location system and 3D display system. The practical application demonstrates that the system is stable, and data transmission is reliable with lower construction cost, which can improve the capability of national rare wildlife monitoring and protection effectively.

  4. A mass balance mercury budget for a mine-dominated lake: Clear Lake, California

    Science.gov (United States)

    Suchanek, T.H.; Cooke, J.; Keller, K.; Jorgensen, S.; Richerson, P.J.; Eagles-Smith, Collin A.; Harner, E.J.; Adam, D.P.

    2009-01-01

    The Sulphur Bank Mercury Mine (SBMM), active intermittently from 1873–1957 and now a USEPA Superfund site, was previously estimated to have contributed at least 100 metric tons (105 kg) of mercury (Hg) into the Clear Lake aquatic ecosystem. We have confirmed this minimum estimate. To better quantify the contribution of the mine in relation to other sources of Hg loading into Clear Lake and provide data that might help reduce that loading, we analyzed Inputs and Outputs of Hg to Clear Lake and Storage of Hg in lakebed sediments using a mass balance approach. We evaluated Inputs from (1) wet and dry atmospheric deposition from both global/regional and local sources, (2) watershed tributaries, (3) groundwater inflows, (4) lakebed springs and (5) the mine. Outputs were quantified from (1) efflux (volatilization) of Hg from the lake surface to the atmosphere, (2) municipal and agricultural water diversions, (3) losses from out-flowing drainage of Cache Creek that feeds into the California Central Valley and (4) biotic Hg removal by humans and wildlife. Storage estimates include (1) sediment burial from historic and prehistoric periods (over the past 150–3,000 years) from sediment cores to ca. 2.5m depth dated using dichloro diphenyl dichloroethane (DDD), 210Pb and 14C and (2) recent Hg deposition in surficial sediments. Surficial sediments collected in October 2003 (11 years after mine site remediation) indicate no reduction (but a possible increase) in sediment Hg concentrations over that time and suggest that remediation has not significantly reduced overall Hg loading to the lake. Currently, the mine is believed to contribute ca. 322–331 kg of Hg annually to Clear Lake, which represents ca. 86–99% of the total Hg loading to the lake. We estimate that natural sedimentation would cover the existing contaminated sediments within ca. 150–300 years.

  5. Morphometric and histopathological parameters of gonadal development in adult common carp from contaminated and reference sites in Lake Mead, Nevada

    Science.gov (United States)

    Patino, R.; Goodbred, S.L.; Draugelis-Dale, R.; Barry, C.E.; Scott, Foott J.; Wainscott, M.R.; Gross, T.S.; Covay, K.J.

    2003-01-01

    This study examined the hypothesis that exposure to sublethal concentrations of contaminants alters the gonadal condition of feral common carp Cyprinus carpio. Adult common carp in Lake Mead, Nevada, were collected from a contaminated site (Las Vegas Bay) that receives municipal and industrial effluent and from a reference site (Overton Arm) with a relatively low level of contamination. Fish were sampled seven times over a 1-year period extending over two separate spawning seasons. Morphometric and histopathological parameters of gonadal and germ cell development were determined. In males, the pattern of seasonal changes in the gonadosomatic index (GSI) was similar between the sites and showed no clear association with site-specific seasonal temperature profiles. However, Las Vegas Bay males had consistently lower GSI values and, on one of the sampling dates, a lower proportion of sperm relative to other germ cell stages (determined histologically). Further, Las Vegas Bay males had a higher incidence of gonadal macrophage aggregates, which are putative tissue biomarkers of contaminant exposure in fishes. In females, seasonal GSI profiles, the frequency of fish with postovulatory follicles (an index of spawning activity), and the timing of new follicle recruitment all showed differences between sites, but these differences generally matched differences in water temperature profile. Also, the peak size-frequency of full-grown follicles did not differ between sites, and estimates of fecundity for the second spawning season indicated that females from the reference site unexpectedly produced a lower number of gametes, Overall, site differences in gonadal condition were observed in carp of both sexes but they seemed to be associated with site differences in contaminant levels only in males. The apparent lack of association between contaminant level and gonadal condition in female carp from mildly mesotrophic Lake Mead may indicate a lack of contaminant effects in

  6. Limnological characteristics of 56 lakes in the Central Canadian Arctic Treeline Region

    Directory of Open Access Journals (Sweden)

    John P. SMOL

    2003-02-01

    Full Text Available Measured environmental variables from 56 lakes across the Central Canadian Treeline Region exhibited clear limnological differences among subpolar ecozones, reflecting strong latitudinal changes in biome characteristics (e.g. vegetation, permafrost, climate. Principal Components Analysis (PCA clearly separated forested sites from tundra sites based on distinct differences in limnological characteristics. Increases in major ions and related variables (e.g. dissolved inorganic carbon, DIC were higher in boreal forest sites in comparison to arctic tundra sites. The higher values recorded in the boreal forest lakes may be indirectly related to differences in climatic factors in these zones, such as the degree of permafrost development, higher precipitation and runoff, duration of ice-cover on the lakes, and thicker and better soil development. Similar to trends observed in DIC, substantially higher values for dissolved organic carbon (DOC were measured in boreal forest lakes than in arctic tundra lakes. This was likely due to higher amounts of catchment-derived DOC entering the lakes from coniferous leaf litter sources. Relative to arctic tundra lakes, boreal forest lakes had higher nutrient concentrations, particularly total nitrogen (TN, likely due to warmer conditions, a longer growing season, and higher precipitation, which would enhance nutrient cycling and primary productivity. Results suggest that modern aquatic environments at opposite sides of the central Canadian arctic treeline (i.e. boreal forest and arctic tundra exhibit distinct differences in water chemistry and physical conditions. These limnological trends may provide important information on possible future changes with additional warming.

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

    Science.gov (United States)

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

    1994-01-01

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

  8. Climatic changes inferred fron analyses of lake-sediment cores, Walker Lake, Nevada

    International Nuclear Information System (INIS)

    Yang, In Che.

    1989-01-01

    Organic and inorganic fractions of sediment collected from the bottom of Walker Lake, Nevada, have been dated by carbon-14 techniques. Sedimentation rates and the organic-carbon content of the sediment were correlated with climatic change. The cold climate between 25,000 and 21,000 years ago caused little runoff, snow accumulation on the mountains, and rapid substantial glacial advances; this period of cold climate resulted in a slow sedimentation rate (0.20 millimeter per year) and in a small organic-carbon content in the sediment. Also, organic-carbon accumulation rates in the lake during this period were slow. The most recent period of slow sedimentation rate and small organic-carbon content occurred between 10,000 and 5500 years ago, indicative of low lake stage and dry climatic conditions. This period of dry climate also was evidenced by dry conditions for Lake Lahontan in Nevada and Searles Lake in California, as cited in the literature. Walker Lake filled rapidly with water between 5500 and 4500 years ago. The data published in this report was not produced under an approved Site Investigation Plan (SIP) or Study Plan (SP) and will not be used in the licensing process. 10 refs., 3 figs., 2 tabs

  9. Local to regional scale industrial heavy metal pollution recorded in sediments of large freshwater lakes in central Europe (lakes Geneva and Lucerne) over the last centuries

    International Nuclear Information System (INIS)

    Thevenon, Florian; Graham, Neil D.; Chiaradia, Massimo; Arpagaus, Philippe; Wildi, Walter; Poté, John

    2011-01-01

    This research first focuses on the spatial and temporal patterns of heavy metals from contrasting environments (highly polluted to deepwater sites) of Lake Geneva. The mercury (Hg) and lead (Pb) records from two deepwater sites show that the heavy metal variations before the industrial period are primarily linked to natural weathering input of trace elements. By opposition, the discharge of industrial treated wastewaters into Vidy Bay of Lake Geneva during the second part of the 20th century, involved the sedimentation of highly metal-contaminated sediments in the area surrounding the WWTP outlet pipe discharge. Eventually, a new Pb isotope record of sediments from Lake Lucerne identifies the long-term increasing anthropogenic lead pollution after ca. 1500, probably due to the development of metallurgical activities during the High Middle Ages. These data furthermore allows to compare the recent anthropogenic sources of water pollution from three of the largest freshwater lakes of Western Europe (lakes Geneva, Lucerne, and Constance). High increases in Pb and Hg highlight the regional impact of industrial pollution after ca. 1750–1850, and the decrease of metal pollution in the 1980s due to the effects of remediation strategies such as the implementation of wastewater treatment plants (WWTPs). However, at all the studied sites, the recent metal concentrations remain higher than pre-industrial levels. Moreover, the local scale pollution data reveal two highly contaminated sites (> 100 μg Pb/g dry weight sediment) by industrial activities, during the late-19th and early-20th centuries (Lake Lucerne) and during the second part of the 20th century (Vidy Bay of Lake Geneva). Overall, the regional scale pollution history inferred from the three large and deep perialpine lakes points out at the pollution of water systems by heavy metals during the last two centuries due to the discharge of industrial effluents. Highlights: ► Natural sources dominated trace element

  10. On the optimization of empirical data concerning radionuclides in water of Lake Juodis

    International Nuclear Information System (INIS)

    Tarasiuk, N.; Koviazina, E.; Shliahtich, E.

    2004-01-01

    Quality of site-dependent water sampling for radionuclide analysis assessing their removal from the complicated aquatic system of eutrophic Lake Juodis is analyzed comparing time courses of site-specific data on standard variables (pH, temperature, redox potential, oxygen concentration, conductivity) in 2003-2004. Compared data were measured simultaneously: a) in the open bottom terrace of the lake adjoining its outflow; b) before the beaver dam bounding the lake rush grown area and c) at the site of the outflowing brook usually used for water sampling for radionuclide analysis. The rush grown area adjoining the outflowing brook is a natural filter for plutonium transport from the lake during warm season as well as for radiocesium activity fraction associated with the suspended matter. Using information on site-specific variations of vertical profiles of standard variables measured in the shallow bottom terrace of the lake, seasonal peculiarities of vertical radionuclide transport in the water column and their release from the sediments are discussed. In winter beaver activities in the lake as well as formation of the anaerobic zone in the rush grown area are considered as supplementary mechanisms facilitating vertical transport of radionuclides in the temperature stratificated water column and their removal from similar lakes. (author)

  11. A short-term look at potential changes in Lake Michigan slimy sculpin diets

    Science.gov (United States)

    French, John R. P.; Stickel, Richard G.; Stockdale, Beth A.; Black, M. Glen

    2010-01-01

    Diporeia hoyi and Mysis relicta are the most important prey items of slimy sculpins (Cottus cognatus) in the Great Lakes. Slimy sculpins were collected from dreissenid-infested bottoms off seven Lake Michigan ports at depths of 27–73 m in fall 2003 to study their lake-wide diets. Relatively large dreissenid biomass occurred at depths of 37- and 46-m. Quagga mussels (Dreissena bugnesis) composed at least 50% of dreissenid biomass at Manistique, Saugatuck, and Sturgeon Bay. Mysis accounted for 82% of the sculpin diet by dry weight at eastern Lake Michigan while Diporeia composed 54–69% of the diet at western Lake Michigan and dominated the diets of slimy sculpins at all sites deeper than 46 m. In northern Lake Michigan, this diet study in new sites showed that slimy sculpin consumed more prey with low energy contents, especially chironomids, than Mysis and Diporeia in shallow sites (depth diet studies on sedentary benthic fishes to be conducted along perimeters of the Great Lakes to observe changes in their diets that may be impacted by changing benthic macroinvertebrate communities.

  12. Assessing lake eutrophication using chironomids: understanding the nature of community response in different lake types

    DEFF Research Database (Denmark)

    Langdon, P. G.; Ruiz, Z.; Brodersen, K. P.

    2006-01-01

    in the original calibration or extended datasets. However, since the transfer functions are based on weighted averages of the trophic optima for the taxa present and not on community similarities, reasonable downcore inferences were produced. Ordination analyses also showed that the lakes retain their 'identity......1. Total phosphorus (TP) and chlorophyll a (Chl a) chironomid inference models ( Brodersen & Lindegaard, 1999 ; Brooks, Bennion & Birks, 2001 ) were used in an attempt to reconstruct changes in nutrients from three very different lake types. Both training sets were expanded, particularly at the low....... A response to nutrients (TP or total nitrogen (TN) ) at this site is also indirect, and the TP reconstruction therefore cannot be reliably interpreted. The third lake, March Ghyll Reservoir has little change in historic chironomid communities, suggesting that this well mixed, relatively unproductive lake has...

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

    Science.gov (United States)

    Manteufel, S. Bridgett; Robertson, Dale M.

    2017-05-25

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

  14. USGS Activities at Lake Roosevelt and the Upper Columbia River

    Science.gov (United States)

    Barton, Cynthia; Turney, Gary L.

    2010-01-01

    Lake Roosevelt (Franklin D. Roosevelt Lake) is the impoundment of the upper Columbia River behind Grand Coulee Dam, and is the largest reservoir within the Bureau of Reclamation's Columbia Basin Project (CBP). The reservoir is located in northeastern Washington, and stretches 151 miles from Grand Coulee Dam north to the Canadian border. The 15-20 miles of the Columbia River downstream of the border are riverine and are under small backwater effects from the dam. Grand Coulee Dam is located on the mainstem of the Columbia River about 90 miles northwest of Spokane. Since the late 1980s, trace-element contamination has been known to be widely present in Lake Roosevelt. Trace elements of concern include arsenic, cadmium, copper, lead, mercury, and zinc. Contaminated sediment carried by the Columbia River is the primary source of the widespread occurrence of trace-element enrichment present in Lake Roosevelt. In 2001, the U.S. Environmental Protection Agency (EPA) initiated a preliminary assessment of environmental contamination of the Lake Roosevelt area (also referred to as Upper Columbia River, UCR site, or UCR/LR site) and has subsequently begun remedial investigations of the UCR site.

  15. Fish impingement at Lake Michigan power plants

    International Nuclear Information System (INIS)

    Sharma, R.K.; Freeman, R.F.; Spigarelli, S.A.

    1976-01-01

    A study was initiated in 1974 to survey the magnitude and to evaluate the impact of fish impingement at 20 power plants on the Great Lakes. Data on impingement rates, site characteristics, intake designs and operational features have been collected and analyzed. Interpretive analyses of these data are in progress. The objectives of this study were: to summarize fish impingement data for Lake Michigan (16/20 plants surveyed are on Lake Michigan); to assess the significance of total and source-related mortalities on populations of forage and predator species; and to expand the assessment of power plant impingement to include all water intakes on Lake Michigan. Data are tabulated

  16. Local to regional scale industrial heavy metal pollution recorded in sediments of large freshwater lakes in central Europe (lakes Geneva and Lucerne) over the last centuries

    Energy Technology Data Exchange (ETDEWEB)

    Thevenon, Florian, E-mail: Florian.Thevenon@yahoo.fr [Institute F.-A. Forel, University of Geneva, Versoix (Switzerland); Graham, Neil D. [Institute F.-A. Forel, University of Geneva, Versoix (Switzerland); Chiaradia, Massimo [Department of Mineralogy, University of Geneva, Geneva (Switzerland); Arpagaus, Philippe; Wildi, Walter; Pote, John [Institute F.-A. Forel, University of Geneva, Versoix (Switzerland)

    2011-12-15

    This research first focuses on the spatial and temporal patterns of heavy metals from contrasting environments (highly polluted to deepwater sites) of Lake Geneva. The mercury (Hg) and lead (Pb) records from two deepwater sites show that the heavy metal variations before the industrial period are primarily linked to natural weathering input of trace elements. By opposition, the discharge of industrial treated wastewaters into Vidy Bay of Lake Geneva during the second part of the 20th century, involved the sedimentation of highly metal-contaminated sediments in the area surrounding the WWTP outlet pipe discharge. Eventually, a new Pb isotope record of sediments from Lake Lucerne identifies the long-term increasing anthropogenic lead pollution after ca. 1500, probably due to the development of metallurgical activities during the High Middle Ages. These data furthermore allows to compare the recent anthropogenic sources of water pollution from three of the largest freshwater lakes of Western Europe (lakes Geneva, Lucerne, and Constance). High increases in Pb and Hg highlight the regional impact of industrial pollution after ca. 1750-1850, and the decrease of metal pollution in the 1980s due to the effects of remediation strategies such as the implementation of wastewater treatment plants (WWTPs). However, at all the studied sites, the recent metal concentrations remain higher than pre-industrial levels. Moreover, the local scale pollution data reveal two highly contaminated sites (> 100 {mu}g Pb/g dry weight sediment) by industrial activities, during the late-19th and early-20th centuries (Lake Lucerne) and during the second part of the 20th century (Vidy Bay of Lake Geneva). Overall, the regional scale pollution history inferred from the three large and deep perialpine lakes points out at the pollution of water systems by heavy metals during the last two centuries due to the discharge of industrial effluents. Highlights: Black-Right-Pointing-Pointer Natural sources

  17. Hydrochemical patterns of a small lake and a stream in an uplifting area proposed as a repository site for spent nuclear fuel, Forsmark, Sweden

    Science.gov (United States)

    Rönnback, Pernilla; Åström, Mats

    2007-10-01

    SummaryThe overall aim of this study was to increase the understanding of the chemical dynamics of small catchments. The focus was on a small oligotropic lake and its major inflow stream in an uplifting area in eastern Sweden (Forsmark) proposed as a repository site for spent nuclear fuel. The hydrochemical sampling campaign lasted for nearly 4 years with sample collection monthly to semi-monthly, and continuous flow measurements carried out over the last 20 months. All this was done as part of the Swedish Nuclear Fuel and Waste Management Company's (SKBs) Site Investigation Programme. The major findings were: (1) as a result of the calcareous overburden caused by redistributed Paleozoic deposits, pH and the Ca and HCO3- concentrations were relatively high in both the stream and lake throughout the period, (2) limnic primary production resulted in decreased concentrations of Ca, HCO3-, NH4+, NO3- and Si, and increased pH and concentrations of chlorophyll a, O 2, DON, POC, PON and POP in the lake in summer, while in other seasons (in winter in particular) when the production was minimal or non-existent the concentrations in the lake and the inflow stream were similar, (3) intrusion of brackish-water resulted in moderately to strongly increased concentrations of Cl -, Na, Mg, Br -, SO42-, K and Sr in the lake: the ratio versus Cl - were for Na and Br - always similar to those in sea water, for Mg and SO42- similar to those in sea water at elevated Cl - concentrations (>3 mM), while K and Sr always occurred in relative excess as compared to sea water, (4) high U concentrations in both the stream and the lake was derived most likely from reduced U-minerals in the overburden and was predicted to be carried to >90% in the form of calcium uranyl carbonate, in a model in which colloidal Fe and Al oxyhydroxides were not considered, (5) the rare earth elements (REEs) had similar concentrations and fractionation patterns in the stream and lake, unlike those found in the

  18. Lake Turkana National Parks Kenya.

    OpenAIRE

    2005-01-01

    Lake Turkana is the largest, most northerly and most saline of Africa's Rift Valley lakes and an outstanding laboratory for the study of plant and animal communities. The three National Parks are a stopover for migrant waterfowl and are major breeding grounds for the Nile crocodile and hippopotamus. The Koobi Fora deposits are rich in pre-human, mammalian, molluscan and other fossil remains and have contributed more to the understanding of Quaternary palaeoenvironments than any other site on ...

  19. Evaluation of a butorphanol, detomidine, and midazolam combination for immobilization of captive Nile lechwe antelopes (Kobus magaceros).

    Science.gov (United States)

    Laricchiuta, Pietro; De Monte, Valentina; Campolo, Marco; Grano, Fabio; Iarussi, Fabrizio; Crovace, Antonio; Staffieri, Francesco

    2012-07-01

    Field immobilization of captive antelope may be required for medical examination, blood sample collection, and animal identification. The aim of this study was to evaluate the effects of a combination of butorphanol, detomidine, and midazolam (BDM) and its partial reversibility in Nile lechwe antelope (Kobus megaceros). Nine captive lechwes, weighing 28-64 kg, were immobilized, in February 2011, with butorphanol 0.20 ± 0.05 (mean ± SD) mg/kg, detomidine 0.20 ± 0.05 mg/kg, and midazolam 0.31 ± 0.08 mg/kg administered intramuscularly (IM) with a blowpipe. Physiologic parameters and depth of anesthesia were recorded when the animals became recumbent at 19.55 ± 8.36 min after darting (T0) and after 10 (T10), 20 (T20), and 30 (T30) min. An arterial blood sample was collected at T20. At the end of the procedures, immobilization was partially reversed with atipamezole 0.25 mg/kg IM. Quality of induction, immobilization, and recovery was scored. The BDM combination induced immobilization and lateral recumbency in 13.44 ± 5.61 min. Median induction score (scored 1 [excellent] to 4 [poor]) was 1 (range 1-2). Heart rate varied 40-104 beats/min, respiratory rate 16-108 breaths/min, and rectal temperature 36.5-40.3 C. Hyperthermia was observed and rapidly treated in three animals that demonstrated insufficient immobilization after darting. Arterial blood gas analyses revealed a mean pH of 7.43 ± 0.07, partial arterial pressure of CO(2) of 44.1 ± 6.0 mmHg, partial arterial pressure of O(2) of 74.0 ± 13.5 mmHg, and an arterial O(2) saturation of 94.77 ± 3.96%. Recovery was smooth and animals were walking in 13.44 ± 7.85 min. Median recovery score (1 = excellent to 4 = poor) was 1 (range 1-2). The BDM was effective in immobilizing captive healthy lechwes with minimal cardiorespiratory changes.

  20. Modelling lake-water photochemistry: three-decade assessment of the steady-state concentration of photoreactive transients (·OH, CO3(-·) and (3)CDOM(∗)) in the surface water of polymictic Lake Peipsi (Estonia/Russia).

    Science.gov (United States)

    Minella, Marco; De Laurentiis, Elisa; Buhvestova, Olga; Haldna, Marina; Kangur, Külli; Maurino, Valter; Minero, Claudio; Vione, Davide

    2013-03-01

    Over the last 3-4 decades, Lake Peipsi water (sampling site A, middle part of the lake, and site B, northern part) has experienced a statistically significant increase of bicarbonate, pH, chemical oxygen demand, nitrate (and nitrite in site B), due to combination of climate change and eutrophication. By photochemical modelling, we predicted a statistically significant decrease of radicals ·OH and CO3(-·) (site A, by 45% and 35%, respectively) and an increase of triplet states of chromophoric dissolved organic matter ((3)CDOM(∗); site B, by ∼25%). These species are involved in pollutant degradation, but formation of harmful by-products is more likely with (3)CDOM(∗) than with ·OH. Therefore, the photochemical self-cleansing ability of Lake Peipsi probably decreased with time, due to combined effects of climate change and eutrophication. In different environments (e.g. Lake Maggiore, NW Italy), ecosystem restoration policies had the additional advantage of enhancing sunlight-driven detoxification, suggesting that photochemical self-cleansing would be positively correlated with lake water quality. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. A chronology for glacial Lake Agassiz shorelines along Upham's namesake transect

    Science.gov (United States)

    Lepper, Kenneth; Buell, Alex W.; Fisher, Timothy G.; Lowell, Thomas V.

    2013-07-01

    Four traditionally recognized strandline complexes in the southern basin of glacial Lake Agassiz are the Herman, Norcross, Tintah and Campbell, whose names correspond to towns in west-central Minnesota that lie on a linear transect defined by the Great Northern railroad grade; the active corridor for commerce at the time when Warren Upham was mapping and naming the shorelines of Lake Agassiz (ca.1880-1895). Because shorelines represent static water planes, their extension around the lake margin establishes time-synchronous lake levels. Transitions between shoreline positions represent significant water-level fluctuations. However, geologic ages have never been obtained from sites near the namesake towns in the vicinity of the southern outlet. Here we report the first geologic ages for Lake Agassiz shorelines obtained at field sites along the namesake transect, and evaluate the emerging chronology in light of other paleoclimate records. Our current work from 11 sampling sites has yielded 16 independent ages. These results combined with a growing OSL age data set for Lake Agassiz's southern basin provide robust age constraints for the Herman, Norcross and Campbell strandlines with averages and standard deviations of 14.1 ± 0.3 ka, 13.6 ± 0.2 ka, and 10.5 ± 0.3 ka, respectively.

  2. Using historical aerial photography and softcopy photogrammetry for waste unit mapping in L Lake

    International Nuclear Information System (INIS)

    Christel, L.M.

    1997-10-01

    L Lake was developed as a cooling water reservoir for the L Reactor at the Savannah River Site. The construction of the lake, which began in the fall of 1984, altered the structure and function of Steel Creek. Completed in the fall of 1985, L Lake has a capacity of 31 million cubic meters and a normal pool of 58 meters. When L Reactor operations ceased in 1988, the water level in the lake still had to be maintained. Site managers are currently trying to determine the feasibility of draining or drawing down the lake in order to save tax dollars. In order to understand the full repercussions of such an undertaking, it was necessary to compile a comprehensive inventory of what the lake bottom looked like prior to filling. Aerial photographs, acquired nine days before the filling of the lake began, were scanned and used for softcopy photogrammetry processing. A one-meter digital elevation model was generated and a digital orthophoto mosaic was created as the base map for the project. Seven categories of features, including the large waste units used to contain the contaminated soil removed from the dam site, were screen digitized and used to generate accurate maps. Other map features include vegetation waste piles, where contaminated vegetation from the flood plain was contained, and ash piles, which are sites where vegetation debris was burned and then covered with clean soil. For all seven categories, the area of disturbance totaled just over 63 hectares. When the screen digitizing was completed, the elevation at the centroid of each disturbance was determined. When the information is used in the Savannah River Site Geographical Information System, it can be used to visualize the various L Lake draw-down scenarios suggested by site managers and hopefully, to support evaluations of the cost effectiveness for each proposed activity

  3. Variations of alkaline phosphatase activity and P fractions in sediments of a shallow Chinese eutrophic lake (Lake Taihu)

    International Nuclear Information System (INIS)

    Zhang Tingxi; Wang Xiaorong; Jin Xiangcan

    2007-01-01

    The distribution of alkaline phosphatase activity (APA) and P fractions in sediment cores and the relationship between them were studied in a shallow Chinese freshwater lake (Lake Taihu). Sediment cores were collected from four sites, characterized by different degrees of eutrophication in June 2004. Sediment P was fractionated into Fe/Al-P, Ca-P, organic P (OP), inorganic P (IP) and total P (TP). The former two species made the largest contribution to the sediment P pool. Results show that trophic status and hydrological conditions have great impact on the APA of the sediments. The order of the APA in sediments was conjectured to be: macrophyte dominated lake > transitional lake > algal dominated lake. APA profiles follow a similar downcore decreasing trend. There was a positive relationship between the APA and the TP, IP. The multiple linear regression equation of the APA and P fractions is: APA = -97 + 0.768TP - 0.985Fe/Al-P. - Characteristics of the alkaline phosphatase activity and P fractions in sediments of different trophic status lake were studied in Lake Taihu

  4. Siderite formation in mining lakes. Sanitation strategy for the Spreetal Nordost lake; Sideritbildung in Tagebaurestseen. Moegliche Sanierungsstrategie des Restlochs Spreetal Nordost

    Energy Technology Data Exchange (ETDEWEB)

    Unger, Y.; Wolkersdorfer, C. [Technische Univ. Bergakademie Freiberg (Germany)

    2006-07-01

    The treatment of acid mine lakes is a worldwide problem. In this study, it will be investigated since the sludge from acid mine drainage (AMD) treatment plants combined with carbon dioxide injections may improve the water quality in such pit lakes. Simultaneously, the emissions of carbon dioxide into the atmosphere may be reduced. The CO{sub 2} will be sequestered in the lake sediments as siderite (FeCO{sub 3}). The acid mine lake Spreetal-Nordost (Lusatia/Germany) was chosen as a test site. Since 1998 iron hydroxide sludge from an AMD treatment plant was deposited into the lake. In preliminary tests the feasibility of this treatment scheme will be investigated. (orig.)

  5. Changes in depth occupied by Great Lakes lake whitefish populations and the influence of survey design

    Science.gov (United States)

    Rennie, Michael D.; Weidel, Brian C.; Claramunt, Randall M.; Dunlob, Erin S.

    2015-01-01

    Understanding fish habitat use is important in determining conditions that ultimately affect fish energetics, growth and reproduction. Great Lakes lake whitefish (Coregonus clupeaformis) have demonstrated dramatic changes in growth and life history traits since the appearance of dreissenid mussels in the Great Lakes, but the role of habitat occupancy in driving these changes is poorly understood. To better understand temporal changes in lake whitefish depth of capture (Dw), we compiled a database of fishery-independent surveys representing multiple populations across all five Laurentian Great Lakes. By demonstrating the importance of survey design in estimating Dw, we describe a novel method for detecting survey-based bias in Dw and removing potentially biased data. Using unbiased Dw estimates, we show clear differences in the pattern and timing of changes in lake whitefish Dw between our reference sites (Lake Superior) and those that have experienced significant benthic food web changes (lakes Michigan, Huron, Erie and Ontario). Lake whitefish Dw in Lake Superior tended to gradually shift to shallower waters, but changed rapidly in other locations coincident with dreissenid establishment and declines in Diporeia densities. Almost all lake whitefish populations that were exposed to dreissenids demonstrated deeper Dw following benthic food web change, though a subset of these populations subsequently shifted to more shallow depths. In some cases in lakes Huron and Ontario, shifts towards more shallow Dw are occurring well after documented Diporeia collapse, suggesting the role of other drivers such as habitat availability or reliance on alternative prey sources.

  6. Microplastic pollution in Vembanad Lake, Kerala, India: The first report of microplastics in lake and estuarine sediments in India.

    Science.gov (United States)

    Sruthy, S; Ramasamy, E V

    2017-03-01

    We present the first study of microplastics in the sediments of Vembanad Lake, a Ramsar site in India. Microplastics are emerging pollutants of increasing environmental concern with a particle size of microplastics pollution on the environment and biota is not well known. Vast data exist in the literature on marine microplastics while reports on freshwater ecosystems are scarce. In this context, to examine the occurrence of microplastic particles (MPs) in the Vembanad Lake, samples were collected from ten sites and processed for microplastic extraction through density separation. Identification of the polymer components of MPs was done using micro Raman spectroscopy. MPs were recovered from all sediment samples, indicating their extensive distribution in the lake. The abundance of MPs recorded from the sediment samples is in the range of 96-496 particles m -2 with a mean abundance of 252.80 ± 25.76 particles m -2 . Low density polyethylene has been identified as the dominant type of polymer component of the MPs. As clams and fishes are the major source of protein to the local population, the presence of MPs in the lake becomes critically important, posing a severe threat of contaminating the food web of this lake. This study, being the first report from India on MPs in lake sediments, provide impetus for further research on the distribution and impact of this emerging pollutant on the biota of many aquatic systems spread across India. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Tale of two pit lakes: initial results of a three-year study of the Main Zone and Waterline pit lakes near Houston, British Columbia, Canada

    Science.gov (United States)

    Crusius, John; Pieters, R.; Leung, A.; Whittle, P.; Pedersen, T.; Lawrence, G.; McNee, J.J.

    2003-01-01

    Pit lakes are becoming increasingly common in North America as well as in the rest of the world. They are created as openpit mines fill passively with ground water and surface inflows on cessation of mining activity. In many instances, the water quality in these pit lakes does not meet regulatory requirements due to a number of influences. The most important are the oxidation of sulfide minerals and the associated release of acid and metals and the flushing of soluble metals during pit filling. Examples of pit lakes with severe water-quality problems include the Berkeley Pit lake (Butte, MT) and the Liberty Pit lake (Nevada), whose waters are characterized by a pH near 3 and Cu concentrations as high as ~150 mg/L (Miller et al., 1996; Davis and Eary, 1997). The importance of the problem can be seen in the fact that some of these sites in the United States are Superfund sites.

  8. Environmental assessment for the natural fluctuation of water level in Par Pond and reduced water flow in Steel Creek below L-Lake at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-01

    The Savannah River Operations Office Strategic Plan directs Savannah River Site (SRS) to find ways to reduce operating costs, and to determine what site infrastructure must be maintained and what infrastructure is surplus. Because of the mission change, L-Lake, Par Pond, and the river water system are no longer needed to support current missions and therefore provide an opportunity for operating cost reduction. If SRS determines that L-Lake, Par Pond, and the river water system are no longer needed to support future missions and are considered surplus, appropriate NEPA documentation will be prepared. The purpose of the proposed action in this Environmental Assessment is to begin an examination of the need for the Site`s river water system by (1) developing data needed to evaluate the potential environmental impacts of further reducing or eliminating the flow demands from the Site`s river water system and; (2) evaluating the potential of reducing operating costs by allowing the water level in Par Pond to fluctuate naturally through reduced pumping. This action also includes reducing the current flow rates from L-Lake to Steel Creek to natural stream flows while maintaining full pool. The recently approved Par Pond CERCLA Interim Action Proposed Plan (IAPP) committed to evaluate in a NEPA document the environmental consequences of this proposed action. This document evaluated the remediation of human health and ecological risks associated with the three year drawdown of Par Pond. Should any of the parameters sampled in the reservoir and streams (e.g., water quality, biota, etc.) exceed established threshold levels during the implementation of the proposed action, water would again be pumped into the reservoir to minimize any impacts by bringing the water level back to an appropriate level about 58.2 m (195 ft).

  9. Do religion and religiosity have anything to do with alcohol consumption patterns? Evidence from two fish landing sites on Lake Victoria Uganda.

    Science.gov (United States)

    Tumwesigye, Nazarius M; Atuyambe, Lynn; Kibira, Simon P S; Wabwire-Mangen, Fred; Tushemerirwe, Florence; Wagner, Glenn J

    2013-09-01

    Fish landing sites have high levels of harmful use of alcohol. This paper examines the role of religion and religiosity on alcohol consumption at two fish landing sites on Lake Victoria in Uganda. Questionnaires were administered to randomly selected people at the sites. Dependent variables included alcohol consumption during the previous 30 days, whereas the key independent variables were religion and religiosity. Bivariate and multivariate analysis techniques were applied. People reporting low religiosity were five times more likely to have consumed alcohol (95% confidence interval: 2.45-10.04) compared with those reporting low/average religiosity. Religion and religiosity are potential channels for controlling alcohol use.

  10. Radial ooids from Great Salt Lake (Utah) as paleoenvironmental archives: Insights from radiocarbon chronology and stable isotopes

    Science.gov (United States)

    Paradis, O. P.; Corsetti, F. A.; Bardsley, A.; Hammond, D. E.; Xu, X.; Walker, J. C.

    2017-12-01

    Ooids (laminated, carbonate coated grains) are ubiquitous in the geologic record in marine and lacustrine settings, and thus remain a common target for geochemical analysis to understand modern and ancient aqueous environments. However, the processes governing ooid formation remain unclear. Recently, radiocarbon dating has revealed that modern marine ooids grow slowly (Beaupre et al. 2015), and laboratory experiments have highlighted the importance of sediment transport and abrasion on net growth rates and ooid size (Trower et al. 2017). Ooid cortex structure includes micritic, tangential and/or radially oriented fabrics. Most modern marine ooids have tangential or micritic cortices, whereas many ancient ooids have radial cortices—thus, there is a need to understand how radial ooids in ancient rocks might inform us about their depositional environment. The Great Salt Lake (GSL), Utah, provides a unique environment to assess the growth rate of primary radial aragonitic ooids. Ooids collected near Antelope Island in the south arm of GSL were sieved, the 355-500 µm fraction was sequentially leached, and 14C of the evolved gas was analyzed to provide a time series of growth. The oldest inorganic carbon of this size fraction has an apparent 14C age of 6600 yr BP, with subsequent growth spanning over 6,000 years. Closed-basin lakes are particularly susceptible to a "reservoir effect" which results in anomalously old apparent radiocarbon ages. The 14C age of the modern dissolved inorganic carbon (DIC) of the south arm was measured to be 295 yr BP, a reservoir age comparable to estimates from lacustrine cave carbonates (McGee et al. 2012). Net growth rate of south arm ooids ranges between 0.01-0.025 µm per year. The δ13C of the outermost cortex suggests that the ooids resemble the modern DIC in the south arm water, suggesting ooids precipitate in equilibrium with lake water. Finer-scale structure in the δ13C of the ooid cortex through time suggests lake level changed

  11. Phase II, Title I engineering assessment of inactive uranium mill tailings, Phillips/United Nuclear Site, Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    1977-12-01

    An engineering assessment was performed of the problems resulting from the existence of radioactive uranium mill tailings at the Phillips/United Nuclear site at Ambrosia Lake, New Mexico. Services included the preparation of topographic maps, the performance of core drillings sufficient to determine areas and volumes of tailings, and radiometric measurements to determine radium-contaminated materials, the evaluation of resulting radiation exposures of individuals and nearby populations, the investigation of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas release from the 2.6 million tons of tailings at the Phillips/United Nuclear site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation are also factors. The estimated radiological health effects to the general population are considered to be minimal. The two alternative actions presented are: dike stabilization, fencing, and maintenance; and adding 2 ft of stabilization cover material. Both options include remedial action at off-site structures and on-site decontamination around the tailings pile. Cost estimates for the two options are $920,000 and $2,230,000, respectively

  12. Position paper on the applicability of supplemental standards to the uppermost aquifer at the Uranium Mill Tailings Vitro Processing Site, Salt Lake City, Utah

    International Nuclear Information System (INIS)

    1996-03-01

    This report documents the results of the evaluation of the potential applicability of supplemental standards to the uppermost aquifer underlying the Uranium Mill Tailings Remedial Action (UMTRA) Project, Vitro Processing Site, Salt Lake City, Utah. There are two goals for this evaluation: provide the landowner with information to make an early qualitative decision on the possible use of the Vitro property, and evaluate the proposed application of supplemental standards as the ground water compliance strategy at the site. Justification of supplemental standards is based on the contention that the uppermost aquifer is of limited use due to wide-spread ambient contamination not related to the previous site processing activities. In support of the above, this report discusses the site conceptual model for the uppermost aquifer and related hydrogeological systems and establishes regional and local background water quality. This information is used to determine the extent of site-related and ambient contamination. A risk-based evaluation of the contaminants' effects on current and projected land uses is also provided. Reports of regional and local studies and U.S. Department of Energy (DOE) site investigations provided the basis for the conceptual model and established background ground water quality. In addition, a limited field effort (4 through 28 March 1996) was conducted to supplement existing data, particularly addressing the extent of contamination in the northwestern portion of the Vitro site and site background ground water quality. Results of the field investigation were particularly useful in refining the conceptual site model. This was important in light of the varied ground water quality within the uppermost aquifer. Finally, this report provides a critical evaluation, along with the related uncertainties, of the applicability of supplemental standards to the uppermost aquifer at the Salt Lake City Vitro processing site

  13. Ecological risk of methylmercury to piscivorous fish of the Great Lakes region.

    Science.gov (United States)

    Sandheinrich, Mark B; Bhavsar, Satyendra P; Bodaly, R A; Drevnick, Paul E; Paul, Eric A

    2011-10-01

    Contamination of fish populations with methylmercury is common in the region of the Laurentian Great Lakes as a result of atmospheric deposition and methylation of inorganic mercury. Using fish mercury monitoring data from natural resource agencies and information on tissue concentrations injurious to fish, we conducted a screening-level risk assessment of mercury to sexually mature female walleye (Sander vitreus), northern pike (Esox lucius), smallmouth bass (Micropterus dolomieu), and largemouth bass (Micropterus salmoides) in the Great Lakes and in interior lakes, impoundments, and rivers of the Great Lakes region. The assessment included more than 43,000 measurements of mercury in fish from more than 2000 locations. Sexually mature female fish that exceeded threshold-effect tissue concentrations of 0.20 μg g(-1) wet weight in the whole body occurred at 8% (largemouth bass) to 43% (walleye) of sites. Fish at 3% to 18% of sites were at risk of injury and exceeded 0.30 μg g(-1) where an alteration in reproduction or survival is predicted to occur. Most fish at increased risk were from interior lakes and impoundments. In the Great Lakes, no sites had sexually mature fish that exceeded threshold-effect concentrations. Results of this screening-level assessment indicate that fish at a substantive number of locations within the Great Lakes region are potentially at risk from methylmercury contamination and would benefit from reduction in mercury concentrations.

  14. Evidence for early hunters beneath the Great Lakes

    OpenAIRE

    O'Shea, John M.; Meadows, Guy A.

    2009-01-01

    Scholars have hypothesized that the poorly understood and rarely encountered archaeological sites from the terminal Paleoindian and Archaic periods associated with the Lake Stanley low water stage (10,000–7,500 BP) are lost beneath the modern Great Lakes. Acoustic and video survey on the Alpena-Amberley ridge, a feature that would have been a dry land corridor crossing the Lake Huron basin during this time period, reveals the presence of a series of stone features that match, in form and loca...

  15. Local to regional scale industrial heavy metal pollution recorded in sediments of large freshwater lakes in central Europe (lakes Geneva and Lucerne) over the last centuries.

    Science.gov (United States)

    Thevenon, Florian; Graham, Neil D; Chiaradia, Massimo; Arpagaus, Philippe; Wildi, Walter; Poté, John

    2011-12-15

    This research first focuses on the spatial and temporal patterns of heavy metals from contrasting environments (highly polluted to deepwater sites) of Lake Geneva. The mercury (Hg) and lead (Pb) records from two deepwater sites show that the heavy metal variations before the industrial period are primarily linked to natural weathering input of trace elements. By opposition, the discharge of industrial treated wastewaters into Vidy Bay of Lake Geneva during the second part of the 20th century, involved the sedimentation of highly metal-contaminated sediments in the area surrounding the WWTP outlet pipe discharge. Eventually, a new Pb isotope record of sediments from Lake Lucerne identifies the long-term increasing anthropogenic lead pollution after ca. 1500, probably due to the development of metallurgical activities during the High Middle Ages. These data furthermore allows to compare the recent anthropogenic sources of water pollution from three of the largest freshwater lakes of Western Europe (lakes Geneva, Lucerne, and Constance). High increases in Pb and Hg highlight the regional impact of industrial pollution after ca. 1750-1850, and the decrease of metal pollution in the 1980s due to the effects of remediation strategies such as the implementation of wastewater treatment plants (WWTPs). However, at all the studied sites, the recent metal concentrations remain higher than pre-industrial levels. Moreover, the local scale pollution data reveal two highly contaminated sites (>100 μg Pb/g dry weight sediment) by industrial activities, during the late-19th and early-20th centuries (Lake Lucerne) and during the second part of the 20th century (Vidy Bay of Lake Geneva). Overall, the regional scale pollution history inferred from the three large and deep perialpine lakes points out at the pollution of water systems by heavy metals during the last two centuries due to the discharge of industrial effluents. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Variation of limnological parameters in a tropical lake used for tilapia cage farming

    Directory of Open Access Journals (Sweden)

    Graciele P. Venturoti

    2015-11-01

    Full Text Available The aim of this study was to assess the effects of tilapia cage culture on the water quality and sediment of Palminhas Lake during both the dry and rainy seasons. Eight sites within the lake (four in fish farms and four in areas without fish farms and one site on an affluent stream were sampled monthly from February 2011 to January 2012. Dissolved oxygen and pH were significantly lower at fish farm sites than at locations without farms, while chlorophyll a was higher at fish farm sites. Moreover, large seasonal variations were observed, which were not related to the fish farms. The Secchi disc depth and ammonia nitrogen level were significantly higher during the dry season, but temperature, dissolved oxygen, pH, total phosphorus and chlorophyll a were significantly higher during the rainy season. The affluent stream contributed substantially to lake eutrophication. Palminhas Lake is mesotrophic and has exhibited a progressive worsening in water quality over the past 20 years. These changes were not caused by fish farming alone but probably by other anthropic activities in the areas surrounding the lake.

  17. Occurrence of and trends in selected sediment-associated contaminants in Caddo Lake, East Texas, 1940-2002

    Science.gov (United States)

    Wilson, Jennifer T.

    2003-01-01

    Bottom-sediment cores were collected from four sites in Caddo Lake in East Texas during May 2002 for analyses of radionuclides (for age dating), organochlorine pesticides, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and major and trace elements, and to describe the occurrence and trends of these sediment-associated contaminants. The Goose Prairie Creek and Harrison Bayou sites receive drainage from an area that includes parts of the now-closed Longhorn Army Ammunitions Plant. The mid-lake site is relatively close to dense oil and gas operations in the lake. The Carter Lake site receives minimal discharge from developed areas. Sediment age (deposition) dates represented in the cores ranged from 1940 to 2002. The only organochlorine compounds detected in all core samples were the DDT degradation products DDE or DDD, and PCB Aroclors 1242, 1254, and 1260 were detected only at the Goose Prairie Creek site. One or more of the DDE concentrations at all sites exceeded a consensus-based threshold effect concentration (on benthic biota), but none exceeded a consensus-based probable effect concentration. The Goose Prairie Creek site had significant downward trends in concentrations of organochlorine compounds, except for no trend in DDE concentrations. The Ammunitions Plant is a possible historical source of the few organochlorine compounds detected at the Goose Prairie Creek and Harrison Bayou sites. PAH concentrations at all sites were below respective threshold effect concentrations. Highest PAH concentrations at all four sites were of C2- alkylated naphthalenes. Nearly all statistically significant PAH trends in the cores were downward. On the basis of PAH source-indicator ratios, the majority of PAH compounds appear to have originated from uncombusted sources such as leaks or spills from oil and gas operations or vehicles (automobiles, boats, aircraft) in the Caddo Lake area. Concentrations of several of the eight trace elements with

  18. Tracing the sources of PCDD/Fs and PCBs in Lake Baikal

    Energy Technology Data Exchange (ETDEWEB)

    Mamontov, A.A.; Mamontova, E.A.; Tarasova, E.N.; McLachlan, M.S.

    2000-03-01

    Lake Baikal is a unique freshwater ecosystem that has been declared a UNESCO World Heritage Site. It contains high levels of PCBs, and Baikal seal were recently found to have PCDD/F concentrations comparable to those in the Baltic Sea. In this work fish and soil were analyzed to trace the sources of these compounds to the lake. The fish samples indicated that the PCDD/F and PCB contamination of Lake Baikal does not originate from background inputs and that the contamination increases from north to south. The soil inventory was determined at 34 sites around Lake Baikal and in the Angara River valley. For the PCDD/Fs and most PCBs, the soil inventory is a good approximation of the cumulative atmospheric deposition. It varied over a factor of 1,000, with the highest levels in Usol'ye Sibirskoe, a city 110 km north of the southwestern tip of the lake in the highly industrialized Angara River valley, and the lowest values in the pristine areas to the northeast of the lake. A continuous decrease in the soil inventory was observed moving from Usol'ye S. up the Angara River valley to Lake Baikal and from there northeastward along the lake.

  19. Climatic Characteristics of the Subtropical Mountainous Cloud Forest at the Yuanyang Lake Long-Term Ecological Research Site, Taiwan

    Directory of Open Access Journals (Sweden)

    I-Ling Lai

    2006-12-01

    Full Text Available To better understand the climatic characteristics in a subtropical mountainous cloud forest at the Yuanyang Lake long-term ecological research site, weather data collected from January 1994 to December 2004 were analyzed in the present study. The obvious seasonal changes in climatic factors were observed at this site. The annual mean air temperature was 12.7°C. The lowest temperature was recorded in February (monthly mean 5.9°C, and the highest one was taken in July (monthly mean 18.1°C. Winter featured light rain with a prolonged occurrence of fog, resulting in a large reduction of radiation. In summer, fog occurred once in the early morning and the other time from afternoon to evening. The latter one was associated with the wind direction changes and usually accompanied with short moderate to heavy convective rain. Consequently the photosynthetic photon flux density (PPFD was high in the morning but reduced drastically in the afternoon. Typhoons occurred in the summer had contributed to 37% of the annual rainfall, usually resulting in torrential rain events and sharp increases in the water level of this lake. As a matter of fact, perhumid environment of this site was attributed to abundant rainfall (mean annual precipitation 3396 mm and high frequency (up to 40% of foggy time. Such conditions would reduce the intensity of solar radiation and PPFD. The average annual solar radiation at the site was 2475 MJ m-2, and annual PPFD was 5713 mol m-2. The average degree of reduction of PPFD under foggy condition was up to 88%. Such climatic characteristics are suggested to constrain the growth of plants and play an important role in competition among plant species in this cloud forest. It is considered that the distinct seasonal fluctuation in environmental factors, perhumid and dim light conditions are the most distinguished characteristics of this subtropical mountainous cloud forest ecosystem.

  20. Evaluation of conceptual, mathematical and physical-and-chemical models for describing subsurface radionuclide transport at the Lake Karachai Waste Disposal Site

    International Nuclear Information System (INIS)

    Rumynin, V.G.; Mironenko, V.A.; Sindalovsky, L.N.; Boronina, A.V.; Konosavsky, P.K.; Pozdniakov, S.P.

    1998-01-01

    The goal of this work was to develop the methodology and to improve understanding of subsurface radionuclide transport for application to the Lake Karachai Site and to identify the influence of the processes and interactions involved into transport and fate of the radionuclides. The report is focused on two sets of problems, which have to do both with, hydrodynamic and hydrogeochemical aspects of the contaminant transport

  1. Tritium in well waters, streams and atomic lakes in the East Kazakhstan Oblast of the Semipalatinsk Nuclear Test Site.

    Science.gov (United States)

    Mitchell, Peter I; Vintró, Luis León; Omarova, Aigul; Burkitbayev, Mukhambetkali; Nápoles, Humberto Jiménez; Priest, Nicholas D

    2005-06-01

    The concentration of tritium has been determined in well waters, streams and atomic lakes in the Sarzhal, Tel'kem, Balapan and Degelen Mountains areas of the Semipalatinsk Test Site. The data show that levels of tritium in domestic well waters within the settlement of Sarzhal are extremely low at the present time with a median value of 4.4 Bq dm(-3) (95% confidence interval:4.1-4.7 Bq dm(-3)). These levels are only marginally above the background tritium content in surface waters globally. Levels in the atomic craters at Tel'kem 1 and Tel'kem 2 are between one and two orders of magnitude higher, while the level in Lake Balapan is approximately 12,600 Bq dm(-3). Significantly, levels in streams and test-tunnel waters sourced in the Degelen Mountains, the site of approximately 215 underground nuclear tests, are a further order of magnitude higher, being in the range 133,000--235,500 Bq dm(-3). No evidence was adduced which indicates that domestic wells in Sarzhal are contaminated by tritium-rich waters sourced in the Degelen massif, suggesting that the latter are not connected hydrologically to the near-surface groundwater recharging the Sarzhal wells. Annual doses to humans arising from the ingestion of tritium in these well waters are very low at the present time and are of no radiological significance.

  2. Water-quality and lake-stage data for Wisconsin lakes, water years 2012–2013

    Science.gov (United States)

    Manteufel, S. Bridgett; Robertson, Dale M.

    2017-05-25

    IntroductionThe U.S. Geological Survey (USGS), in cooperation with local and other agencies, collects data at selected lakes throughout Wisconsin. These data, accumulated over many years, provide a data base for developing an improved understanding of the water quality of lakes. To make these data available to interested parties outside the USGS, the data are published annually in this report series. The locations of water-quality and lake-stage stations in Wisconsin for water year 2012 are shown in figure 1. A water year is the 12-month period from October 1 through September 30. It is designated by the calendar year in which it ends. Thus, the period October 1, 2011 through September 30, 2012, is called “water year 2012.”The purpose of this report is to provide information about the chemical and physical characteristics of Wisconsin lakes. Data that have been collected at specific lakes, and information to aid in the interpretation of those data, are included in this report. Data collected include measurements of in-lake water quality and lake stage. Time series of Secchi depths, surface total phosphorus and chlorophyll a concentrations collected during non-frozen periods are included for all lakes. Graphs of vertical profiles of temperature, dissolved oxygen, pH, and specific conductance are included for sites where these parameters were measured. Descriptive information for each lake includes: location of the lake, area of the lake’s watershed, period for which data are available, revisions to previously published records, and pertinent remarks. Additional data, such as streamflow and water quality in tributary and outlet streams of some of the lakes, are published online at http://nwis.waterdata.usgs.gov/wi/nwis.Water-resources data, including stage and discharge data at most streamflow-gaging stations, are available online. The Wisconsin Water Science Center’s home page is at https://www.usgs.gov/centers/wisconsin-water-science-center. Information on

  3. Recolonization and possible recovery of burrowing mayflies (Ephemeroptera: Ephemeridae: Hexagenia spp.) in Lake Erie of the Laurentian Great Lakes

    Science.gov (United States)

    Schloesser, Don W.; Krieger, Kenneth A.; Ciborowski, Jan J.H.; Corkum, Lynda D.

    2000-01-01

    Burrowing mayflies of the genus Hexagenia spp. were widely distributed (ca. 80% of sites) and abundant (ca. 160 nymphs/m2) in the western basin of Lake Erie of the Laurentian Great Lakes in 1929–1930, prior to a period of anoxia in the mid 1950s. Nymphs were absent or rare in the basin between 1961 and 1973–1975. In 1979–1991, nymphs were infrequently found (13–46% of sites) in low abundance (3–40 nymphs/m2) near shore (recolonized sediments of western Lake Erie and that their abundance may be similar to levels observed before their disappearance in the mid 1950s. However, prior to the mid 1950s, densities were greater in offshore than nearshore waters, but between 1979 and 1998 greater densities occurred near shore than offshore. In addition, there were two areas in the 1990s where low densities consistently occurred. Therefore, recovery of nymphs in western Lake Erie may not have been complete in 1998. At present we do not know the cause for the sudden recolonization of nymphs in large portions of western Lake Erie. Undoubtedly, pollution-abatement programs contributed to improved conditions that would have ultimately led to mayfly recovery in the future. However, the explosive growth of the exotic zebra mussel, Dreissena polymorpha, undoubtedly diverted plankton foods to bottom substrates which could have increased the speed at which Hexagenia spp. nymphs recolonized sediments in western Lake Erie in the 1990s.

  4. Loktak Lake, Manipur, northeast India: a Ramsar site with rich rotifer (Rotifera: Eurotatoria diversity and its meta-analysis

    Directory of Open Access Journals (Sweden)

    Bhushan Kumar Sharma

    2016-04-01

    Full Text Available A total of 162 species (S of Rotifera belonging to 40 genera and 20 families examined from Loktak Lake, an important floodplain lake of northeast India (NEI that is one of the richest assemblages of the taxon known from the Indian sub-region. It merits biodiversity value as ~40.0% and ~62.0% of species recorded from India and NEI, respectively. One species is new to India, 23 species are new to Manipur and 14 species are new to Loktak basin. Biogeographically interesting elements included three Australasian, five Oriental, ten palaeotropical and one cosmo-subtropical species. Lecanidae > Lepadellidae > Brachionidae > Trichocercidae collectively comprised 65.4% of S; Lecane > Lepadella > Trichocerca are diverse genera; and paucity of Brachionus spp. is distinct. Loktak Rotifera indicated importance of cosmopolitan, the littoral-periphytonic and small-sized species, and ‘tropical character’. ANOVA recorded significant variations of the rotifer richness amongst three sampling sites of Loktak during June 2010–May 2012 survey. The richness followed osscillaring monthly variations and indicated lack of significant influence of any individual abioitic parameter at all three stations.

  5. 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

  6. Fine-scale acoustic telemetry reveals unexpected lake trout, Salvelinus namaycush, spawning habitats in northern Lake Huron, North America

    Science.gov (United States)

    Binder, Thomas; Farha, Steve A.; Thompson, Henry T.; Holbrook, Christopher; Bergstedt, Roger A.; Riley, Stephen; Bronte, Charles R.; He, Ji; Krueger, Charles C.

    2018-01-01

    Previous studies of lake trout, Salvelinus namaycush, spawning habitat in the Laurentian Great Lakes have used time- and labour-intensive survey methods and have focused on areas with historic observations of spawning aggregations and on habitats prejudged by researchers to be suitable for spawning. As an alternative, we used fine-scale acoustic telemetry to locate, describe and compare lake trout spawning habitats. Adult lake trout were implanted with acoustic transmitters and tracked during five consecutive spawning seasons in a 19–27 km2 region of the Drummond Island Refuge, Lake Huron, using the VEMCO Positioning System. Acoustic telemetry revealed discrete areas of aggregation on at least five reefs in the study area, subsequently confirmed by divers to contain deposited eggs. Notably, several identified spawning sites would likely not have been discovered using traditional methods because either they were too small and obscure to stand out on a bathymetric map or because they did not conform to the conceptual model of spawning habitat held by many biologists. Our most unique observation was egg deposition in gravel and rubble substrates located at the base of and beneath overhanging edges of large boulders. Spawning sites typically comprised <10% of the reef area and were used consistently over the 5-year study. Evaluation of habitat selection from the perspective of fish behaviour through use of acoustic transmitters offers potential to expand current conceptual models of critical spawning habitat.

  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. Mercury levels, reproduction, and hematology in western grebes from three California Lakes, USA

    Energy Technology Data Exchange (ETDEWEB)

    Elbert, R.A.; Anderson, D.W. [Univ. of California, Davis, CA (United States). Wildlife, Fish, and Conservation Biology

    1998-02-01

    Twenty-three healthy adult western and Clark`s grebes (Aechmorphorus occidentalis and Aechmorphorus clarkii) were collected at three study sites in California, USA, in 1992: Clear Lake, Lake County; Eagle Lake, Lassen County; and Tule Lake, Siskiyou County. Liver, kidney, breast muscle, and brain were analyzed for total mercury (Hg) concentration (ppm wet weight), and blood was analyzed for various blood parameters. Clear Lake birds had greater Hg concentrations in kidney, breast muscle, and brain than birds from the other two lakes whereas liver concentrations were not statistically different. Average concentrations for Clear Lake birds were 2.74 ppm for liver, 2.06 ppm for kidney, 1.06 ppm for breast muscle, and 0.28 ppm for brain. The tissue levels of kidney, breast muscle, and brain at the other two study sites were one half the levels found at Clear Lake. These mean tissue levels were near, but below, those known to cause adverse effects. When data from all sites were merged, kidney, breast muscle, and brain concentrations are positively correlated to each other. Liver concentrations were not correlated to any other value. Brain Hg concentrations were also negatively correlated to blood potassium and blood phosphorus levels. Kidney Hg levels were positively correlated to percent blood heterophils and negatively correlated to percent eosinophils, suggesting that mercury levels might be affecting immune function. These biomarkers could not be related to any obvious ecological effects.

  9. 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.

  10. Gaseous and Freely-Dissolved PCBs in the Lower Great Lakes Based on Passive Sampling: Spatial Trends and Air-Water Exchange.

    Science.gov (United States)

    Liu, Ying; Wang, Siyao; McDonough, Carrie A; Khairy, Mohammed; Muir, Derek C G; Helm, Paul A; Lohmann, Rainer

    2016-05-17

    Polyethylene passive sampling was performed to quantify gaseous and freely dissolved polychlorinated biphenyls (PCBs) in the air and water of Lakes Erie and Ontario during 2011-2012. In view of differing physical characteristics and the impacts of historical contamination by PCBs within these lakes, spatial variation of PCB concentrations and air-water exchange across these lakes may be expected. Both lakes displayed statistically similar aqueous and atmospheric PCB concentrations. Total aqueous concentrations of 29 PCBs ranged from 1.5 pg L(-1) in the open lake of Lake Erie (site E02) in 2011 spring to 105 pg L(-1) in Niagara (site On05) in 2012 summer, while total atmospheric concentrations were 7.7-634 pg m(-3) across both lakes. A west-to-east gradient was observed for aqueous PCBs in Lake Erie. River discharge and localized influences (e.g., sediment resuspension and regional alongshore transport) likely dominated spatial trends of aqueous PCBs in both lakes. Air-water exchange fluxes of Σ7PCBs ranged from -2.4 (±1.9) ng m(-2) day(-1) (deposition) in Sheffield (site E03) to 9.0 (±3.1) ng m(-2) day(-1) (volatilization) in Niagara (site On05). Net volatilization of PCBs was the primary trend across most sites and periods. Almost half of variation in air-water exchange fluxes was attributed to the difference in aqueous concentrations of PCBs. Uncertainty analysis in fugacity ratios and mass fluxes in air-water exchange of PCBs indicated that PCBs have reached or approached equilibrium only at the eastern Lake Erie and along the Canadian shore of Lake Ontario sites, where air-water exchange fluxes dominated atmospheric concentrations.

  11. Feeding ecology of lake whitefish larvae in eastern Lake Ontario

    Science.gov (United States)

    Johnson, James H.; McKenna, James E.; Chalupnicki, Marc A.; Wallbridge, Tim; Chiavelli, Rich

    2009-01-01

    We examined the feeding ecology of larval lake whitefish (Coregonus clupeaformis) in Chaumont Bay, Lake Ontario, during April and May 2004-2006. Larvae were collected with towed ichthyoplankton nets offshore and with larval seines along the shoreline. Larval feeding periodicity was examined from collections made at 4-h intervals over one 24-h period in 2005. Inter-annual variation in diet composition (% dry weight) was low, as was spatial variation among collection sites within the bay. Copepods (81.4%), primarily cyclopoids (59.1%), were the primary prey of larvae over the 3-year period. Cladocerans (8.1%; mainly daphnids, 6.7%) and chironomids (7.3%) were the other major prey consumed. Larvae did not exhibit a preference for any specific prey taxa. Food consumption of lake whitefish larvae was significantly lower at night (i.e., 2400 and 0400 h). Substantial variation in diet composition occurred over the 24-h diel study. For the 24-h period, copepods were the major prey consumed (50.4%) and their contribution in the diet ranged from 29.3% (0400 h) to 85.9% (1200 h). Chironomids made up 33.4% of the diel diet, ranging from 8.0% (0800 h) to 69.9% (0400 h). Diel variation in the diet composition of lake whitefish larvae may require samples taken at several intervals over a 24-h period to gain adequate representation of their feeding ecology.

  12. Data report: Jean Lake Area, Nevada. National Uranium Resource Evaluation Program

    International Nuclear Information System (INIS)

    Cook, J.R.

    1982-05-01

    This report presents the results of detailed sampling of soils, rocks, and dry lake bed material from the area of Jean Dry Lake in southern Nevada. The study area is in the Kingman 1 0 x 2 0 quadrangle of the National Topographic Map Series. Samples were collected from 1000 sites. The target density of sampling was 16 sites per square mile in the lake bed and four sites per square mile for soil samples. Neutron activation analyses are presented for uranium and 16 other elements. Scintillometer readings are reported for each site. Analytical data and scintillometer measurements are presented in tables. Statistical summaries and a brief description of the results are given. Data from the sites (on microfiche in pocket) include; (1) elemental analyses (U, Th, Hf, Al, Ce, Dy, Eu, Fe, La, Lu, Mn, Sc, Sm, Na, Ti, and V); and (2) scintillometer readings. To make the data available for public use without further delay, this report is being issued without the normal technical and copy editing

  13. Geomorphic and sedimentologic evidence for the separation of Lake Superior from Lake Michigan and Huron

    Science.gov (United States)

    Johnston, J.W.; Thompson, T.A.; Wilcox, D.A.; Baedke, S.J.

    2007-01-01

    A common break was recognized in four Lake Superior strandplain sequences using geomorphic and sedimentologic characteristics. Strandplains were divided into lakeward and landward sets of beach ridges using aerial photographs and topographic surveys to identify similar surficial features and core data to identify similar subsurface features. Cross-strandplain, elevation-trend changes from a lowering towards the lake in the landward set of beach ridges to a rise or reduction of slope towards the lake in the lakeward set of beach ridges indicates that the break is associated with an outlet change for Lake Superior. Correlation of this break between study sites and age model results for the strandplain sequences suggest that the outlet change occurred sometime after about 2,400 calendar years ago (after the Algoma phase). Age model results from one site (Grand Traverse Bay) suggest an alternate age closer to about 1,200 calendar years ago but age models need to be investigated further. The landward part of the strandplain was deposited when water levels were common in all three upper Great Lakes basins (Superior, Huron, and Michigan) and drained through the Port Huron/Sarnia outlet. The lakeward part was deposited after the Sault outlet started to help regulate water levels in the Lake Superior basin. The landward beach ridges are commonly better defined and continuous across the embayments, more numerous, larger in relief, wider, have greater vegetation density, and intervening swales contain more standing water and peat than the lakeward set. Changes in drainage patterns, foreshore sediment thickness and grain size help in identifying the break between sets in the strandplain sequences. Investigation of these breaks may help identify possible gaps in the record or missing ridges in strandplain sequences that may not be apparent when viewing age distributions and may justify the need for multiple age and glacial isostatic adjustment models. ?? 2006 Springer Science

  14. Late Quaternary lake-level changes constrained by radiocarbon and stable isotope studies on sediment cores from Lake Titicaca, South America

    Science.gov (United States)

    Rowe, Harold D.; Guilderson, Thomas P.; Dunbar, Robert B.; Southon, John R.; Seltzer, Geoffrey O.; Mucciarone, David A.; Fritz, Sherilyn C.; Baker, Paul A.

    2003-09-01

    We present and compare AMS- 14C geochronologies for sediment cores recovered from Lake Titicaca, South America. Radiocarbon dates from three core sites constrain the timing of late Quaternary paleoenvironmental changes in the Central Andes and highlight the site-specific factors that limit the radiocarbon geochronometer. With the exception of mid-Holocene sediments, all cores are generally devoid of macrophyte fragments, thus bulk organic fractions are used to build core chronologies. Comparisons of radiocarbon results for chemically defined fractions (bulk decalcified, humate, humin) suggest that ages derived from all fractions are generally coherent in the post-13,500 yr BP time interval. In the pre-13,500 yr BP time interval, ages derived from humate extracts are significantly younger (300-7000 years) than ages from paired humin residues. Gross age incoherencies between paired humate and humin sub-fractions in pre-13,500 yr BP sediments from all core sites probably reflect the net downward migration of humates. Ages derived from bulk decalcified fractions at our shallow water (90 m) and deep water (230 m) core sites consistently fall between ages derived from humate and humin sub-fractions in the pre-13,500 yr BP interval, reflecting that the bulk decalcified fraction is predominantly a mixture of humate and humin sub-fractions. Bulk decalcified ages from the pre-13,500 yr BP interval at our intermediate depth core site (150 m) are consistently older than humate (youngest) and humin sub-fractions. This uniform, reproducible pattern can be explained by the mobilization of a relatively older organic sub-fraction during and after the re-acidification step following the alkaline treatment of the bulk sediment. The inferred existence of this 'alkali-mobile, acid-soluble' sub-fraction implies a different depositional/post-depositional history that is potentially associated with a difference in source material. While internally consistent geochronologies can be

  15. Water Quality Conditions in Upper Klamath and Agency Lakes, Oregon, 2006

    Science.gov (United States)

    Lindenberg, Mary K.; Hoilman, Gene; Wood, Tamara M.

    2008-01-01

    The U.S. Geological Survey Upper Klamath Lake water quality monitoring program gathered information from multiparameter continuous water quality monitors, physical water samples, dissolved oxygen production and consumption experiments, and meteorological stations during the June-October 2006 field season. The 2006 study area included Agency Lake and all of Upper Klamath Lake. Seasonal patterns in water quality were similar to those observed in 2005, the first year of the monitoring program, and were closely related to bloom dynamics of the cyanobacterium (blue-green alga) Aphanizomenon flos-aquae (AFA) in the two lakes. High dissolved oxygen and pH conditions in both lakes before the bloom declined in July, which coincided with seasonal high temperatures and resulted in seasonal lows in dissolved oxygen and decreased pH. Dissolved oxygen and pH in Upper Klamath and Agency Lakes increased again after the bloom recovered. Seasonal low dissolved oxygen and decreased pH coincided with seasonal highs in ammonia and orthophosphate concentrations. Seasonal maximum daily average temperatures were higher and minimum dissolved oxygen concentrations were lower in 2006 than in 2005. Conditions potentially harmful to fish were influenced by seasonal patterns in bloom dynamics and bathymetry. Potentially harmful low dissolved oxygen and high un-ionized ammonia concentrations occurred mostly at the deepest sites in the Upper Klamath Lake during late July, coincident with a bloom decline. Potentially harmful pH conditions occurred mostly at sites outside the deepest parts of the lake in July and September, coincident with a heavy bloom. Instances of possible gas bubble formation, inferred from dissolved oxygen data, were estimated to occur frequently in shallow areas of Upper Klamath and Agency Lakes simultaneously with potentially harmful pH conditions. Comparison of the data from monitors in nearshore areas and monitors near the surface of the water column in the open waters of

  16. Fish Lake, Utah - a promising long core site straddling the Great Basin to Colorado Plateau transition zone

    Science.gov (United States)

    Marchetti, D. W.; Abbott, M. B.; Bailey, C.; Wenrich, E.; Stoner, J. S.; Larsen, D. J.; Finkenbinder, M. S.; Anderson, L.; Brunelle, A.; Carter, V.; Power, M. J.; Hatfield, R. G.; Reilly, B.; Harris, M. S.; Grimm, E. C.; Donovan, J.

    2015-12-01

    Fish Lake (~7x1.5 km and 2696 m asl) is located on the Fish Lake Plateau in central Utah. The Lake occupies a NE-striking tectonic graben; one of a suite of grabens on the Plateau that cut 21-26 Ma volcanic rocks. The lake outflows via Lake Creek to the NE where it joins Sevenmile Creek to become the Fremont River, a tributary to the Colorado River. A bathymetric survey reveals a mean depth of 27 m and a max depth of 37.2 m. The lake bottom slopes from NW to SE with the deepest part near the SE wall, matching the topographic expression of the graben. Nearby Fish Lake Hightop (3545 m) was glaciated with an ice field and outlet glaciers. Exposure ages indicate moraine deposition during Pinedale (15-23 ka) and Bull Lake (130-150 ka) times. One outlet glacier at Pelican Canyon deposited moraines and outwash into the lake but the main basin of the lake was never glaciated. Gravity measurements indicate that lake sediments thicken toward the SE side of the lake and the thickest sediment package is modeled to be between 210 and 240 m. In Feb 2014 we collected cores from Fish Lake using a 9-cm diameter UWITECH coring system in 30.5 m of water. A composite 11.2-m-long core was constructed from overlapping 2 m drives that were taken in triplicate to ensure total recovery and good preservation. Twelve 14C ages and 3 tephra layers of known age define the age model. The oldest 14C age of 32.3±4.2 cal ka BP was taken from 10.6 m. Core lithology, CT scans, and magnetic susceptibility (ms) reveal three sediment packages: an organic-rich, low ms Holocene to post-glacial section, a fine-grained, minerogenic glacial section with high ms, and a short section of inferred pre-LGM sediment with intermediate composition. Extrapolating the age model to the maximum estimated sediment thicknesses suggest sediments may be older than 500-700 ka. Thus Fish Lake is an ideal candidate for long core retrieval as it likely contains paleoclimatic records extending over multiple glacial cycles.

  17. Phylogenetic Diversity of Archaea and Bacteria in the Anoxic Zone of a Meromictic Lake (Lake Pavin, France)▿ †

    Science.gov (United States)

    Lehours, Anne-Catherine; Evans, Paul; Bardot, Corinne; Joblin, Keith; Gérard, Fonty

    2007-01-01

    The compositions of archaeal and bacterial populations at different depths (60 m [mixolimnion-chemocline interface], 70 m [chemocline-subchemocline interface], 90 m, and 92 m [the water-sediment interface]) in the anoxic zone of the water column in Lake Pavin, a freshwater permanently stratified mountain lake in France, were determined. Phylogenetic trees were constructed from sequences to assess archaeal and bacterial diversity at the four sites. PMID:17261512

  18. Ecosystem element transport model for Lake Eckarfjaerden

    Energy Technology Data Exchange (ETDEWEB)

    Konovalenko, L.; Bradshaw, C. [The Department of Ecology, Environment and Plant Sciences, Stockholm University (Sweden); Andersson, E.; Kautsky, U. [Swedish Nuclear Fuel and Waste Management Co. - SKB (Sweden)

    2014-07-01

    The ecosystem transport model of elements was developed for Lake Eckarfjaerden located in the Forsmark area in Sweden. Forsmark has currently a low level repository (SFR) and a repository for spent fuel is planned. A large number of data collected during site-investigation program 2002-2009 for planning the repository were available for the creation of the compartment model based on carbon circulation, physical and biological processes (e.g. primary production, consumption, respiration). The model is site-specific in the sense that the food web model is adapted to the actual food web at the site, and most estimates of biomass and metabolic rates for the organisms and meteorological data originate from site data. The functional organism groups of Lake Eckarfjaerden were considered as separate compartments: bacterio-plankton, benthic bacteria, macro-algae, phytoplankton, zooplankton, fish, benthic fauna. Two functional groups of bacteria were taken into account for the reason that they have the highest biomass of all functional groups during the winter, comprising 36% of the total biomass. Effects of ecological parameters, such as bacteria and algae biomass, on redistribution of a hypothetical radionuclide release in the lake were examined. The ecosystem model was used to estimate the environmental transfer of several elements (U, Th, Ra) and their isotopes (U-238, U-234,Th-232, Ra-226) to various aquatic organisms in the lake, using element-specific distribution coefficients for suspended particle and sediment. Results of chemical analyses of the water, sediment and biota were used for model validation. The model gives estimates of concentration factors for fish based on modelling rather on in situ measurement, which reduces the uncertainties for many radionuclides with scarce of data. Document available in abstract form only. (authors)

  19. Identifying Watershed Regions Sensitive to Soil Erosion and Contributing to Lake Eutrophication—A Case Study in the Taihu Lake Basin (China)

    Science.gov (United States)

    Lin, Chen; Ma, Ronghua; He, Bin

    2015-01-01

    Taihu Lake in China is suffering from severe eutrophication partly due to non-point pollution from the watershed. There is an increasing need to identify the regions within the watershed that most contribute to lake water degradation. The selection of appropriate temporal scales and lake indicators is important to identify sensitive watershed regions. This study selected three eutrophic lake areas, including Meiliang Bay (ML), Zhushan Bay (ZS), and the Western Coastal region (WC), as well as multiple buffer zones next to the lake boundary as the study sites. Soil erosion intensity was designated as a watershed indicator, and the lake algae area was designated as a lake quality indicator. The sensitive watershed region was identified based on the relationship between these two indicators among different lake divisions for a temporal sequence from 2000 to 2012. The results show that the relationship between soil erosion modulus and lake quality varied among different lake areas. Soil erosion from the two bay areas was more closely correlated with water quality than soil erosion from the WC region. This was most apparent at distances of 5 km to 10 km from the lake, where the r2 was as high as 0.764. Results indicate that soil erosion could be used as an indicator for identifying key watershed protection areas. Different lake areas need to be considered separately due to differences in geographical features, land use, and the corresponding effects on lake water quality. PMID:26712772

  20. Identifying Watershed Regions Sensitive to Soil Erosion and Contributing to Lake Eutrophication--A Case Study in the Taihu Lake Basin (China).

    Science.gov (United States)

    Lin, Chen; Ma, Ronghua; He, Bin

    2015-12-24

    Taihu Lake in China is suffering from severe eutrophication partly due to non-point pollution from the watershed. There is an increasing need to identify the regions within the watershed that most contribute to lake water degradation. The selection of appropriate temporal scales and lake indicators is important to identify sensitive watershed regions. This study selected three eutrophic lake areas, including Meiliang Bay (ML), Zhushan Bay (ZS), and the Western Coastal region (WC), as well as multiple buffer zones next to the lake boundary as the study sites. Soil erosion intensity was designated as a watershed indicator, and the lake algae area was designated as a lake quality indicator. The sensitive watershed region was identified based on the relationship between these two indicators among different lake divisions for a temporal sequence from 2000 to 2012. The results show that the relationship between soil erosion modulus and lake quality varied among different lake areas. Soil erosion from the two bay areas was more closely correlated with water quality than soil erosion from the WC region. This was most apparent at distances of 5 km to 10 km from the lake, where the r² was as high as 0.764. Results indicate that soil erosion could be used as an indicator for identifying key watershed protection areas. Different lake areas need to be considered separately due to differences in geographical features, land use, and the corresponding effects on lake water quality.

  1. Hypervariability of ribosomal DNA at multiple chromosomal sites in lake trout (Salvelinus namaycush).

    Science.gov (United States)

    Zhuo, L; Reed, K M; Phillips, R B

    1995-06-01

    Variation in the intergenic spacer (IGS) of the ribosomal DNA (rDNA) of lake trout (Salvelinus namaycush) was examined. Digestion of genomic DNA with restriction enzymes showed that almost every individual had a unique combination of length variants with most of this variation occurring within rather than between populations. Sequence analysis of a 2.3 kilobase (kb) EcoRI-DraI fragment spanning the 3' end of the 28S coding region and approximately 1.8 kb of the IGS revealed two blocks of repetitive DNA. Putative transcriptional termination sites were found approximately 220 bases (b) downstream from the end of the 28S coding region. Comparison of the 2.3-kb fragments with two longer (3.1 kb) fragments showed that the major difference in length resulted from variation in the number of short (89 b) repeats located 3' to the putative terminator. Repeat units within a single nucleolus organizer region (NOR) appeared relatively homogeneous and genetic analysis found variants to be stably inherited. A comparison of the number of spacer-length variants with the number of NORs found that the number of length variants per individual was always less than the number of NORs. Examination of spacer variants in five populations showed that populations with more NORs had more spacer variants, indicating that variants are present at different rDNA sites on nonhomologous chromosomes.

  2. Effect of site on sedimentological characteristics and metal pollution in two semi-enclosed embayments of great freshwater reservoir: Lake Nasser, Egypt

    Science.gov (United States)

    Farhat, Hassan I.; Aly, Walid

    2018-05-01

    This study was carried out to assess the effect of site on the spatial variations of sedimentological characteristics and heavy metal pollution of two semi-enclosed embayments of Lake Nasser. Grain Size, texture and mode of transportation as well as some heavy metals and organic matter were assessed in sediment samples from those embayments. The results indicated that the grain size of the lake sediments was affected by site variation. Moreover, heavy metal distribution in the sediments was mainly directed by grain size distribution and organic matter, though, the organic matter was more critical than grain size in controlling heavy metals distribution in each embayment. The main source of heavy metals in studied embayments was concluded to be the metals brought with flood waters rather than being of anthropogenic origin. The results also indicated the association of studied metals with Fe and Mn oxides of suspended matters and dissolved solids which come with flood water and trapped and settled to the bottom sediment in the stagnation period. Measured indices indicated that southern embayment is more polluted than northern one, which could be explained on the basis that the southern embayment reserves larger amounts of suspended matter coming with the flood than northern embayment.

  3. 1975 progress report: Idaho National Engineering Laboratory site radioecology--ecology programs

    International Nuclear Information System (INIS)

    Markham, O.D.

    1976-06-01

    Results are reported from measurements of the content of various radionuclides in the tissues of wild animals on or near the Idaho National Engineering Laboratory sampled during 1975. Tissue samples from antelope, waterfowl, rodents, rabbits, and doves were analyzed for 13 radionuclides, including 134 Cs, 137 Cs, 95 Zr, 95 Nb, 103 Ru, 238 Pu, 239 Pu, 90 Sr, 131 I, and 60 Co which were responsible for the largest amounts of radioactivity. Measurements were also made of the content of 238 Pu, 239 Pu, and 241 Am in soil samples and the radioactivity in tumbling weeds at the radioactive waste management site. Data are included from studies on the ecology of the pygmy rabbit, Salvilagus idahoensis, amphibians, reptiles, birds of prey, rodents, and coyotes, and vegetation in relation to land use at the site. Seasonal variations in the deposition and retention of 141 Ce and 134 Cs on sagebrush and bottlebrush grass were compared

  4. Tritium in well waters, streams and atomic lakes in the East Kazakhstan Oblast of the Semipalatinsk Nuclear Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Peter I [Department of Experimental Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Vintro, Luis Leon [Department of Experimental Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Omarova, Aigul [Department of Experimental Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Burkitbayev, Mukhambetkali [Department of Inorganic Chemistry, Al-Farabi Kazakh National University, Almaty (Kazakhstan); Napoles, Humberto Jimenez [Department of Experimental Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Priest, Nicholas D [School of Health and Social Sciences, Middlesex University, Enfield EN3 4SA (United Kingdom)

    2005-06-01

    The concentration of tritium has been determined in well waters, streams and atomic lakes in the Sarzhal, Tel'kem, Balapan and Degelen Mountains areas of the Semipalatinsk Test Site. The data show that levels of tritium in domestic well waters within the settlement of Sarzhal are extremely low at the present time with a median value of 4.4 Bq dm{sup -3} (95% confidence interval: 4.1-4.7 Bq dm{sup -3}). These levels are only marginally above the background tritium content in surface waters globally. Levels in the atomic craters at Tel'kem 1 and Tel'kem 2 are between one and two orders of magnitude higher, while the level in Lake Balapan is approximately 12 600 Bq dm{sup -3}. Significantly, levels in streams and test-tunnel waters sourced in the Degelen Mountains, the site of approximately 215 underground nuclear tests, are a further order of magnitude higher, being in the range 133 000-235 500 Bq dm{sup -3}. No evidence was adduced which indicates that domestic wells in Sarzhal are contaminated by tritium-rich waters sourced in the Degelen massif, suggesting that the latter are not connected hydrologically to the near-surface groundwater recharging the Sarzhal wells. Annual doses to humans arising from the ingestion of tritium in these well waters are very low at the present time and are of no radiological significance.

  5. Local to regional scale industrial heavy metal pollution recorded in sediments of large freshwater lakes in central Europe (lakes Geneva and Lucerne) over the last centuries

    OpenAIRE

    Thevenon F; Graham ND; Chiaradia M; Arpagaus P; Wildi W; Pote J

    2011-01-01

    This research first focuses on the spatial and temporal patterns of heavy metals from contrasting environments (highly polluted to deepwater sites) of Lake Geneva. The mercury (Hg) and lead (Pb) records from two deepwater sites show that the heavy metal variations before the industrial period are primarily linked to natural weathering input of trace elements. By opposition the discharge of industrial treated wastewaters into Vidy Bay of Lake Geneva during the second part of the 20th century i...

  6. Final report. Conceptual studies nuclear energy center Lake Hartwell, S.C., Phase III

    International Nuclear Information System (INIS)

    1981-01-01

    This document summarizes a conceptual study on the feasibility and practicality of developing a nuclear energy center (NEC) at a specific site in the SSEB region. The site selected for this conceptual study is at Lake Hartwell, South Carolina. The conceptual NEC at Lake Hartwell consists of twelve nuclear electric generating units, arranged on the site in four clusters of three units each, known as triads. The nominal distance between triads was selected as 2-1/2 miles. Each unit was assumed to be a 1250 MW(e). The total electric output of 15,000 MWe would be transmitted to five major utilities in South Carolina, North Carolina, and Georgia. The basic finding was that the concept of a NEC on the Lake Hartwell site is feasible, but further analysis of institutional issues and possible legislation would be required

  7. Catchment tracers reveal discharge, recharge and sources of groundwater-borne pollutants in a novel lake modelling approach

    Science.gov (United States)

    Kristensen, Emil; Madsen-Østerbye, Mikkel; Massicotte, Philippe; Pedersen, Ole; Markager, Stiig; Kragh, Theis

    2018-02-01

    Groundwater-borne contaminants such as nutrients, dissolved organic carbon (DOC), coloured dissolved organic matter (CDOM) and pesticides can have an impact the biological quality of lakes. The sources of pollutants can, however, be difficult to identify due to high heterogeneity in groundwater flow patterns. This study presents a novel approach for fast hydrological surveys of small groundwater-fed lakes using multiple groundwater-borne tracers. Water samples were collected from the lake and temporary groundwater wells, installed every 50 m within a distance of 5-45 m to the shore, were analysed for tracer concentrations of CDOM, DOC, total dissolved nitrogen (TDN, groundwater only), total nitrogen (TN, lake only), total dissolved phosphorus (TDP, groundwater only), total phosphorus (TP, lake only), δ18O / δ16O isotope ratios and fluorescent dissolved organic matter (FDOM) components derived from parallel factor analysis (PARAFAC). The isolation of groundwater recharge areas was based on δ18O measurements and areas with a high groundwater recharge rate were identified using a microbially influenced FDOM component. Groundwater discharge sites and the fractions of water delivered from the individual sites were isolated with the Community Assembly via Trait Selection model (CATS). The CATS model utilized tracer measurements of TDP, TDN, DOC and CDOM from the groundwater samples and related these to the tracer measurements of TN, TP, DOC and CDOM in the lake. A direct comparison between the lake and the inflowing groundwater was possible as degradation rates of the tracers in the lake were taken into account and related to a range of water retention times (WRTs) of the lake (0.25-3.5 years in 0.25-year increments). These estimations showed that WRTs above 2 years required a higher tracer concentration of inflowing water than found in any of the groundwater wells around the lake. From the estimations of inflowing tracer concentration, the CATS model isolated

  8. Mercury levels in herring gulls and fish: 42 years of spatio-temporal trends in the Great Lakes.

    Science.gov (United States)

    Blukacz-Richards, E Agnes; Visha, Ariola; Graham, Matthew L; McGoldrick, Daryl L; de Solla, Shane R; Moore, David J; Arhonditsis, George B

    2017-04-01

    Total mercury levels in aquatic birds and fish communities have been monitored across the Canadian Great Lakes by Environment and Climate Change Canada (ECCC) for the past 42 years (1974-2015). These data (22 sites) were used to examine spatio-temporal variability of mercury levels in herring gull (Larus argentatus) eggs, lake trout (Salvelinus namaycush), walleye (Sander vitreus), and rainbow smelt (Osmerus mordax). Trends were quantified with dynamic linear models, which provided time-variant rates of change of mercury concentrations. Lipid content (in both fish and eggs) and length in fish were used as covariates in all models. For the first three decades, mercury levels in gull eggs and fish declined at all stations. In the 2000s, trends for herring gull eggs reversed at two sites in Lake Erie and two sites in Lake Ontario. Similar trend reversals in the 2000s were observed for lake trout in Lake Superior and at a single station in Lake Ontario. Mercury levels in lake trout continued to slowly decline at all of the remaining stations, except for Lake Huron, where the levels remained stable. A post-hoc Bayesian regression analysis suggests strong trophic interactions between herring gulls and rainbow smelt in Lake Superior and Lake Ontario, but also pinpoints the likelihood of a trophic decoupling in Lake Huron and Lake Erie. Continued monitoring of mercury levels in herring gulls and fish is required to consolidate these trophic shifts and further evaluate their broader implications. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  9. Executive summary. Conceptual studies nuclear energy center Lake Hartwell, S.C., Phase III

    International Nuclear Information System (INIS)

    1981-01-01

    This document summarizes a conceptual study on the feasibility and practicality of developing a nuclear energy center (NEC) at a specific site in the SSEB region. The site selected for this conceptual study is at Lake Hartwell, South Carolina. The conceptual NEC at Lake Hartwell consists of twelve 1250-MW(e) LWRs arranged on the site in four cluster of three units each, know as triads. The nominal distance between triads was selected as 2-1/2 miles. The total electric output of 15,000 MWe to be generated by the NEC would be transmitted to five major utilities in South Carolina, North Carolina, and Georgia. Objective of the study was to assess the technical, socioeconomic, environmental, and institutional issues relating to the NEC at the conceptual study site. The basic finding was that the concept of a NEC on the Lake Hartwell site is feasible, but further analysis of institutional issues and possible legislation would be required

  10. Evidence for early hunters beneath the Great Lakes.

    Science.gov (United States)

    O'Shea, John M; Meadows, Guy A

    2009-06-23

    Scholars have hypothesized that the poorly understood and rarely encountered archaeological sites from the terminal Paleoindian and Archaic periods associated with the Lake Stanley low water stage (10,000-7,500 BP) are lost beneath the modern Great Lakes. Acoustic and video survey on the Alpena-Amberley ridge, a feature that would have been a dry land corridor crossing the Lake Huron basin during this time period, reveals the presence of a series of stone features that match, in form and location, structures used for caribou hunting in both prehistoric and ethnographic times. These results present evidence for early hunters on the Alpena-Amberley corridor, and raise the possibility that intact settlements and ancient landscapes are preserved beneath Lake Huron.

  11. 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.

  12. Empirical models of wind conditions on Upper Klamath Lake, Oregon

    Science.gov (United States)

    Buccola, Norman L.; Wood, Tamara M.

    2010-01-01

    Upper Klamath Lake is a large (230 square kilometers), shallow (mean depth 2.8 meters at full pool) lake in southern Oregon. Lake circulation patterns are driven largely by wind, and the resulting currents affect the water quality and ecology of the lake. To support hydrodynamic modeling of the lake and statistical investigations of the relation between wind and lake water-quality measurements, the U.S. Geological Survey has monitored wind conditions along the lakeshore and at floating raft sites in the middle of the lake since 2005. In order to make the existing wind archive more useful, this report summarizes the development of empirical wind models that serve two purposes: (1) to fill short (on the order of hours or days) wind data gaps at raft sites in the middle of the lake, and (2) to reconstruct, on a daily basis, over periods of months to years, historical wind conditions at U.S. Geological Survey sites prior to 2005. Empirical wind models based on Artificial Neural Network (ANN) and Multivariate-Adaptive Regressive Splines (MARS) algorithms were compared. ANNs were better suited to simulating the 10-minute wind data that are the dependent variables of the gap-filling models, but the simpler MARS algorithm may be adequate to accurately simulate the daily wind data that are the dependent variables of the historical wind models. To further test the accuracy of the gap-filling models, the resulting simulated winds were used to force the hydrodynamic model of the lake, and the resulting simulated currents were compared to measurements from an acoustic Doppler current profiler. The error statistics indicated that the simulation of currents was degraded as compared to when the model was forced with observed winds, but probably is adequate for short gaps in the data of a few days or less. Transport seems to be less affected by the use of the simulated winds in place of observed winds. The simulated tracer concentration was similar between model results when

  13. Reconstructing Heat Fluxes Over Lake Erie During the Lake Effect Snow Event of November 2014

    Science.gov (United States)

    Fitzpatrick, L.; Fujisaki-Manome, A.; Gronewold, A.; Anderson, E. J.; Spence, C.; Chen, J.; Shao, C.; Posselt, D. J.; Wright, D. M.; Lofgren, B. M.; Schwab, D. J.

    2017-12-01

    The extreme North American winter storm of November 2014 triggered a record lake effect snowfall (LES) event in southwest New York. This study examined the evaporation from Lake Erie during the record lake effect snowfall event, November 17th-20th, 2014, by reconstructing heat fluxes and evaporation rates over Lake Erie using the unstructured grid, Finite-Volume Community Ocean Model (FVCOM). Nine different model runs were conducted using combinations of three different flux algorithms: the Met Flux Algorithm (COARE), a method routinely used at NOAA's Great Lakes Environmental Research Laboratory (SOLAR), and the Los Alamos Sea Ice Model (CICE); and three different meteorological forcings: the Climate Forecast System version 2 Operational Analysis (CFSv2), Interpolated observations (Interp), and the High Resolution Rapid Refresh (HRRR). A few non-FVCOM model outputs were also included in the evaporation analysis from an atmospheric reanalysis (CFSv2) and the large lake thermodynamic model (LLTM). Model-simulated water temperature and meteorological forcing data (wind direction and air temperature) were validated with buoy data at three locations in Lake Erie. The simulated sensible and latent heat fluxes were validated with the eddy covariance measurements at two offshore sites; Long Point Lighthouse in north central Lake Erie and Toledo water crib intake in western Lake Erie. The evaluation showed a significant increase in heat fluxes over three days, with the peak on the 18th of November. Snow water equivalent data from the National Snow Analyses at the National Operational Hydrologic Remote Sensing Center showed a spike in water content on the 20th of November, two days after the peak heat fluxes. The ensemble runs presented a variation in spatial pattern of evaporation, lake-wide average evaporation, and resulting cooling of the lake. Overall, the evaporation tended to be larger in deep water than shallow water near the shore. The lake-wide average evaporations

  14. Hydrology and water quality of Park Lake, south-central Wisconsin

    Science.gov (United States)

    Kammerer, P.A.

    1996-01-01

    Park Lake extends to the northeast from the village of Pardeeville in Columbia County (fig. 1). Local residents perceive water-quality problems in the lake that include excessive algae and aquatic plant growth. Algae and plant growth in a lake are controlled, in part, by the availability of phosphorus in the water. However, no measurements of phosphorus enter- ing the lake or of other factors that affect lake-water quality had been made, and available data on water quality were limited to 2 years of measurements at one site in the lake in 1986- 87. To obtain the data and in- formation needed to address the water-quality problems at Park Lake and to develop a management plan that would limit the input of phosphorus to the lake, the U.S. Geologi- cal Survey, in cooperation with the Park Lake Management District, studied the hydrology of the lake and collected data needed to determine sources and amount of phosphorus en- tering the lake. This Fact Sheet summarizes the results of that study. Data collected during the study were published in a separate report (Holmstrom and others, 1994, p. 70-85).

  15. Multi-Elements in Waters and Sediments of Shallow Lakes: Relationships with Water, Sediment, and Watershed Characteristics.

    Science.gov (United States)

    Kissoon, La Toya T; Jacob, Donna L; Hanson, Mark A; Herwig, Brian R; Bowe, Shane E; Otte, Marinus L

    2015-06-01

    We measured concentrations of multiple elements, including rare earth elements, in waters and sediments of 38 shallow lakes of varying turbidity and macrophyte cover in the Prairie Parkland (PP) and Laurentian Mixed Forest (LMF) provinces of Minnesota. PP shallow lakes had higher element concentrations in waters and sediments compared to LMF sites. Redundancy analysis indicated that a combination of site- and watershed-scale features explained a large proportion of among-lake variability in element concentrations in lake water and sediments. Percent woodland cover in watersheds, turbidity, open water area, and macrophyte cover collectively explained 65.2 % of variation in element concentrations in lake waters. Sediment fraction smaller than 63 µm, percent woodland in watersheds, open water area, and sediment organic matter collectively explained 64.2 % of variation in element concentrations in lake sediments. In contrast to earlier work on shallow lakes, our results showed the extent to which multiple elements in shallow lake waters and sediments were influenced by a combination of variables including sediment characteristics, lake morphology, and percent land cover in watersheds. These results are informative because they help illustrate the extent of functional connectivity between shallow lakes and adjacent lands within these lake watersheds.

  16. A 9,000-year-old caribou hunting structure beneath Lake Huron

    OpenAIRE

    O’Shea, John M.; Lemke, Ashley K.; Sonnenburg, Elizabeth P.; Reynolds, Robert G.; Abbott, Brian D.

    2014-01-01

    Some of the most pivotal questions in human history necessitate the investigation of archaeological sites that are now under water. These contexts have unique potentials for preserving ancient sites without disturbance from later human occupation. The Alpena-Amberley Ridge beneath modern Lake Huron in the Great Lakes offers unique evidence of prehistoric caribou hunters for a time period that is very poorly known on land. The newly discovered Drop 45 Drive Lane and associated artifacts presen...

  17. Development of Petrov glacial-lake system (Tien Shan and outburst risk assessment

    Directory of Open Access Journals (Sweden)

    I. A. Torgoev

    2013-01-01

    Full Text Available Global climate warming causes an intensive melting and retreat of glaciers in the Tien Shan mountains. Melting water of glaciers causes overfilling of high mountain lakes. The increase of the surface and volume of the Petrov Lake accompanied with the decrease of stability of the dam represents an extremely dangerous situation that can produce a natural disaster. Failure can happen due to erosion, a buildup of water pressure, an earthquake or if a large enough portion of a glacier breaks off and massively displaces the waters in a glacial lake at its base. In case of the lake dam rupture, flooding of a disposal site of highly toxic tailing from the gold mine Kumtor is a threat. If this happens, the toxic waste containing cyanides would contaminate a large area in the Naryn (Syrdarya river basin. Even if the flooding of the disposal site does not occur, the damage after lake dam fracture will be immense due to the glacial lake outburst flood may be a devastating mudslide. In order to prevent or reduce the risk of this event we recommend performing engineering surveys for the development and implementation of the project for the controlled reduction of water level in the Blue Bay of the Petrov Lake to a safe volume.

  18. Radiological investigations at the 'Taiga' nuclear explosion site: Site description and in situ measurements

    Energy Technology Data Exchange (ETDEWEB)

    Ramzaev, V., E-mail: V.Ramzaev@mail.ru [Institute of Radiation Hygiene, Mira str. 8, 197101 St.-Petersburg (Russian Federation); Repin, V.; Medvedev, A.; Khramtsov, E.; Timofeeva, M.; Yakovlev, V. [Institute of Radiation Hygiene, Mira str. 8, 197101 St.-Petersburg (Russian Federation)

    2011-07-15

    In the summer of 2009, we performed a field survey of the 'Taiga' peaceful underground nuclear explosion site, the Perm region, Russia (61.30{sup o} N, 56.60{sup o} E). The explosion was carried out by the USSR in 1971. This paper provides an extended summary of the available published data on the 'Taiga' experiment. A detailed description of the site is illustrated by original aerial and ground-level photos. A large artificial lake (700 m long and 350 m wide) currently occupies the central area of the experimental site. The ground lip surrounding the lake is covered by a newly grown mixed forest. In situ measurements, performed in August 2009, revealed elevated levels of the {gamma}-ray dose rate in air on the banks of the lake 'Taiga'. Two hot spots were detected on the eastern bank of the lake. The excess of the {gamma}-ray radiation is attributable to the man-made radionuclides {sup 60}Co and {sup 137}Cs. The current external {gamma}-ray dose rate to a human from the contaminations associated with the 'Taiga' experiment was between 9 and 70 {mu}Sv per week. Periodic monitoring the site is recommended. - Highlights: > We studied a radiation anomaly at the 'Taiga' underground nuclear explosion site. > The anomaly currently has an area of approximately 1 km{sup 2}. > The excess of {gamma}-ray radiation at the site is mainly attributable to {sup 60}Co and {sup 137}Cs. > The external effective dose may currently exceed the negligible value of 10 {mu}Sv y{sup -1}.

  19. Engineering assessment of inactive uranium mill tailings: Phillips/United Nuclear site, Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    1981-10-01

    Ford, Bacon and Davis Utah, Inc., has reevaluated the Phillips/United Nuclear site in order to revise the December 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Ambrosia Lake, New Mexico. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from 2.6 million dry tons of tailings at the Phillips/United Nuclear site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The four alternative actions presented in this engineering assessment range from millsite decontamination with the addition of 3 m of stabilization cover material, to removal of the tailings to remote disposal sites and decontamination of the tailings site. Cost estimates for the four options range from about $21,500,000 for stabilization in-place, to about $45,200,000 for disposal at a distance of about 15 mi. Three principal alternatives for the reprocessing of the Phillips/United Nuclear tailings were examined: heap leaching; treatment at an existing mill; and reprocessing at a new conventional mill constructed for tailings reprocessing.The cost of the uranium recovered would be about $87/lb of U 3 O 8 by either heap leach or conventional plant process. The spot market price for uranium was $25/lb early in 1981. Reprocessing the Phillips/United Nuclear tailings for uranium recovery does not appear to be economically attractive under present or foreseeable market conditions

  20. Identifying non-point sources of endocrine active compounds and their biological impacts in freshwater lakes

    Science.gov (United States)

    Baker, Beth H.; Martinovic-Weigelt, Dalma; Ferrey, Mark L.; Barber, Larry B.; Writer, Jeffrey H.; Rosenberry, Donald O.; Kiesling, Richard L.; Lundy, James R.; Schoenfuss, Heiko L.

    2014-01-01

    Contaminants of emerging concern, particularly endocrine active compounds (EACs), have been identified as a threat to aquatic wildlife. However, little is known about the impact of EACs on lakes through groundwater from onsite wastewater treatment systems (OWTS). This study aims to identify specific contributions of OWTS to Sullivan Lake, Minnesota, USA. Lake hydrology, water chemistry, caged bluegill sunfish (Lepomis macrochirus), and larval fathead minnow (Pimephales promelas) exposures were used to assess whether EACs entered the lake through OWTS inflow and the resultant biological impact on fish. Study areas included two OWTS-influenced near-shore sites with native bluegill spawning habitats and two in-lake control sites without nearby EAC sources. Caged bluegill sunfish were analyzed for plasma vitellogenin concentrations, organosomatic indices, and histological pathologies. Surface and porewater was collected from each site and analyzed for EACs. Porewater was also collected for laboratory exposure of larval fathead minnow, before analysis of predator escape performance and gene expression profiles. Chemical analysis showed EACs present at low concentrations at each study site, whereas discrete variations were reported between sites and between summer and fall samplings. Body condition index and liver vacuolization of sunfish were found to differ among study sites as did gene expression in exposed larval fathead minnows. Interestingly, biological exposure data and water chemistry did not match. Therefore, although results highlight the potential impacts of seepage from OWTS, further investigation of mixture effects and life history factor as well as chemical fate is warranted.

  1. Environmental assessment for the natural fluctuation of water level in Par Pond and reduced water flow in Steel Creek below L-Lake at the Savannah River Site

    International Nuclear Information System (INIS)

    1995-08-01

    The Savannah River Operations Office Strategic Plan directs Savannah River Site (SRS) to find ways to reduce operating costs, and to determine what site infrastructure must be maintained and what infrastructure is surplus. Because of the mission change, L-Lake, Par Pond, and the river water system are no longer needed to support current missions and therefore provide an opportunity for operating cost reduction. If SRS determines that L-Lake, Par Pond, and the river water system are no longer needed to support future missions and are considered surplus, appropriate NEPA documentation will be prepared. The purpose of the proposed action in this Environmental Assessment is to begin an examination of the need for the Site's river water system by (1) developing data needed to evaluate the potential environmental impacts of further reducing or eliminating the flow demands from the Site's river water system and; (2) evaluating the potential of reducing operating costs by allowing the water level in Par Pond to fluctuate naturally through reduced pumping. This action also includes reducing the current flow rates from L-Lake to Steel Creek to natural stream flows while maintaining full pool. The recently approved Par Pond CERCLA Interim Action Proposed Plan (IAPP) committed to evaluate in a NEPA document the environmental consequences of this proposed action. This document evaluated the remediation of human health and ecological risks associated with the three year drawdown of Par Pond. Should any of the parameters sampled in the reservoir and streams (e.g., water quality, biota, etc.) exceed established threshold levels during the implementation of the proposed action, water would again be pumped into the reservoir to minimize any impacts by bringing the water level back to an appropriate level about 58.2 m (195 ft)

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

    Science.gov (United States)

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

    2016-06-01

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

  3. Modern processes of sediment formation in Lake Towuti, Indonesia, as derived from the composition of lake surface sediments

    Science.gov (United States)

    Hasberg, Ascelina; Melles, Martin; Morlock, Marina; Vogel, Hendrik; Russel, James M.; Bijaksana, Satria

    2016-04-01

    In summer 2015, a drilling operation funded by the International Continental Scientific Drilling Program (ICDP) was conducted at Lake Towuti (2.75°S, 121.5°E), the largest tectonically formed lake (surface area: 561 km²) of the Republic Indonesia. The Towuti Drilling Project (TDP) recovered more than 1000 meters of sediment core from three sites. At all three sites replicate cores down to 133, 154, and 174 m below lake floor have penetrated the entire lake sediment record, which is expected to comprise the past ca. 650.000 years continuously. Lake Towutís sediment record thus can provide unique information for instance concerning the climatic and environmental history in the Indo-Pacific-Warm-Pool (IPWP) and concerning the evolutionary biology in SE Asia. For a better understanding of the palaeoenvironmental proxies to be analyzed on the drill cores, the modern processes of sediment formation in the lake and in its catchment - under known environmental conditions - were investigated on a set of 84 lake sediment surface samples. Sampling was conducted by grab sampler (UWITEC Corp., Austria) in a grid of 1 to 4 km resolution that covers the entire lake. The samples were analyzed for inorganic geochemical composition (XRF powder scans and ICP-MS), magnetic susceptibility (Kappabridge), grain-size distribution (laser scanner), biogenic components (smear-slide analyses), biogenic silica contents (leaching), and carbonate, total organic carbon (TOC), nitrogen (TN), and sulfur (TS) concentrations (elemental analyzer). The sediments close to the lake shores and in front of the major river inlets are characterized by mean grain sizes coarser than average and high magnetic susceptibilities presented by high ratios of Cr, Ni, Co, and Zr. This reflects higher energies due to wave action and fluvial sediment supply, as well as the occurrence of magnetic minerals particularly in the sand and gravel fractions of the sediments. In regions of deeper waters and more distal to

  4. The environmental state of Lake Ladoga sediments, Russia

    International Nuclear Information System (INIS)

    Pellinen, J.; Ristola, T.; Kukkonen, J.; Leppaenen, M.; Hoof, P.L. van; Robbins, J.A.

    1994-01-01

    The authors collected sediments in the summer 1993 from Lake Ladoga for chemical analyses and toxicity tests to assess the state of the lake. The sediments were analyzed for heavy metals, fluorides, chlorinated hydrocarbons, polyaromatic hydrocarbons, and certain radionuclides related to the fallout from the Chernobyl accident. In general, the concentrations of toxic chemicals were low. Most chemicals were below the limit of detection. The range of the total concentration of 17 PCB congeners was from 6 to 30 ng/kg dw; the highest value was at the pulp and paper mill located in the northeastern shore of the lake (Pitkaeranta). The highest concentrations of Cr, Co, Ni, Cu, Zn, Pb were 10, 42, 46, 36, 188, and 143 μg/g dw, respectively. Arsene was not detected at all and Cd only at one out of 12 sites studied. The toxicological testing with larvae of a midge, Chironomus riparius, and Daphnia magna resulted in only slight effects which may in part be related to different physical characteristics of the sediments rather than to toxic effects. The highest mortality was 75% at the deepest part of the lake (close to Valamo Island) which was believed to be the least polluted. The highest heavy metal concentrations and slow development of the larvae were observed for the same site. In the south of the lake at the Volhov Bay which receives effluents from forest and aluminum industry, the mortality was 10--50%

  5. Key Lake human resources and northern business initiative

    International Nuclear Information System (INIS)

    Dudar, R.; McIntyre, J.; McInnes, B.P.

    1994-01-01

    The Key Lake Operation is committed to a policy of maximizing Saskatchewan, and particularly northern Saskatchewan, employment and business opportunities. The participation rate of northern people in the Key Lake operation's workforce has risen from 23.8% in 1983, to 42% today. Cameco's objective is to achieve 50% representation of residents of Saskatchewan's north in the Key Lake workforce by 1995. The company also extends this strategic objective to contractors. All contractors are required to maximize employment opportunities for residents of Saskatchewan's north, and report employment levels to the company as a condition of the contract. Today, contractors at the Key Lake site have achieved a northern participation rate of 47%. This paper highlights strategies for increasing northern/aboriginal participation and provides several examples of successes from these initiatives. (author)

  6. Secondary Pollutants in the Lake Tahoe Basin, USA

    Science.gov (United States)

    Zielinska, B.; Bytnerowicz, A.; Gertler, A.; McDaniel, M.; Burley, J. D.

    2013-12-01

    Lake Tahoe, located at 6,225 ft. (1,897 m) in the Sierra Nevada mountain range, is the largest alpine lake in North America. Known for the clarity of its water and the panorama of surrounding mountains on all sides, Lake Tahoe is a prime tourist attraction in the California - Nevada area. However, the Lake Tahoe Basin is facing significant problems in air quality and declining water clarity. In July 21 - 26, 2012, we conducted a field study in the Basin designed to characterize the precursors and pathways of secondary pollutant formation, including ozone, secondary organic aerosol (SOA) and ammonium nitrate. Four strategic sampling sites were selected inside the Basin; two of these sites were located at high elevation (one each on the western and eastern sides of the Basin) and two were positioned near the Lake level. Ozone and NO/NO2 concentrations were continuously measured. With a resolution of several hours over a 6-day sampling period we collected canister samples for detailed speciation of volatile organic compounds (VOC), 2,4-dinitrophenylhydrazine (DNPH) impregnated Sep-Pak cartridges for analysis of carbonyl compounds and honeycomb denuder/filter pack samples for measurement of concentrations of ammonia, nitrous acid, nitric acid, and fine particulate ammonium nitrate. We also collected PM2.5 Teflon and quartz filter samples for measurements of mass, organic and elemental carbon (OC/EC) concentrations and speciation of organic compounds. Whereas the concentrations of lower molecular weight (mw) C2 - C3 hydrocarbons were generally the highest in all sampling sites, ranging from 25 to 76% of the total measured VOC (over 70 species from C2 to C10), the concentrations of biogenic hydrocarbons, isoprene and α-pinene were significant, ranging from 1.4 to 26% and 1.5 to 30%, respectively, of the total VOC, depending on the site and sampling period. For comparison, the sum of benzene, toluene, ethylbenzene and xylenes (BTEX) constituted from 2.5 to 37% of the

  7. Lake Michigan Offshore Wind Feasibility Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Boezaart, Arnold [GVSU; Edmonson, James [GVSU; Standridge, Charles [GVSU; Pervez, Nahid [GVSU; Desai, Neel [University of Michigan; Williams, Bruce [University of Delaware; Clark, Aaron [GVSU; Zeitler, David [GVSU; Kendall, Scott [GVSU; Biddanda, Bopi [GVSU; Steinman, Alan [GVSU; Klatt, Brian [Michigan State University; Gehring, J. L. [Michigan State University; Walter, K. [Michigan State University; Nordman, Erik E. [GVSU

    2014-06-30

    project including to: 1) test and validate floating LIDAR technology; 2) collect and access offshore wind data; 3) detect and measure bird and bat activity over Lake Michigan; 4) conduct an over water sound propagation study; 5) prepare and offer a college course on offshore energy, and; 6) collect other environmental, bathometric, and atmospheric data. Desk-top research was performed to select anchorage sites and to secure permits to deploy the buoy. The project also collected and analyzed data essential to wind industry investment decision-making including: deploying highly mobile floating equipment to gather offshore wind data; correlating offshore wind data with conventional on-shore MET tower data; and performing studies that can contribute to the advancement and deployment of offshore wind technologies. Related activities included: • Siting, permitting, and deploying an offshore floating MET facility; • Validating the accuracy of floating LWS using near shoreline cup anemometer MET instruments; • Assessment of laser pulse technology (LIDAR) capability to establish hub height measurement of wind conditions at multiple locations on Lake Michigan; • Utilizing an extended-season (9-10 month) strategy to collect hub height wind data and weather conditions on Lake Michigan; • Investigation of technology best suited for wireless data transmission from distant offshore structures; • Conducting field-validated sound propagation study for a hypothetical offshore wind farm from shoreline locations; • Identifying the presence or absence of bird and bat species near wind assessment facilities; • Identifying the presence or absence of benthic and pelagic species near wind assessment facilities; All proposed project activities were completed with the following major findings: • Floating Laser Wind Sensors are capable of high quality measurement and recordings of wind resources. The WindSentinel presented no significant operational or statistical limitations in

  8. If an antelope is a document, then a rock is data: preserving earth science samples for the future

    Science.gov (United States)

    Ramdeen, S.

    2015-12-01

    As discussed in seminal works by Briet (1951) and Buckland (1998), physical objects can be considered documents when given specific context. In the case of an antelope, in the wild it's an animal, in a zoo it's a document. It is the primary source of information, specifically when it is made an object of study. When discussing earth science data, we may think about numbers in a spreadsheet or verbal descriptions of a rock. But what about physical materials such as cores, cuttings, fossils, and other tangible objects? The most recent version of the American Geophysical Union's data position statement states data preservation and management policies should apply to both "digital data and physical objects"[1]. If an antelope is a document, than isn't a rock a form of data? Like books in a library or items in a museum, these objects require surrogates (digital or analog) that allow researchers to access and retrieve them. Once these scientific objects are acquired, researchers can process the information they contain. Unlike books, and some museum materials, most earth science objects cannot yet be completely replaced by digital surrogates. A fossil may be scanned, but the original is needed for chemical testing and ultimately for 'not yet developed' processes of scientific analysis. These objects along with their metadata or other documentation become scientific data when they are used in research. Without documentation of key information (i.e. the location where it was collected) these objects may lose their scientific value. This creates a complex situation where we must preserve the object, its metadata, and the connection between them. These factors are important as we consider the future of earth science data, our definitions of what constitutes scientific data, as well as our data preservation and management practices. This talk will discuss current initiatives within the earth science communities (EarthCube's EC3 and iSamples; USGS's data preservation program

  9. Impact of methane flow through deformable lake sediments on atmospheric release

    Science.gov (United States)

    Scandella, B.; Juanes, R.

    2010-12-01

    Methane is a potent greenhouse gas that is generated geothermally and biologically in lake and ocean sediments. Free gas bubbles may escape oxidative traps and contribute more to the atmospheric source than dissolved methane, but the details of the methane release depend on the interactions between the multiple fluid phases and the deformable porous medium. We present a model and supporting laboratory experiments of methane release through “breathing” dynamic flow conduits that open in response to drops in the hydrostatic load on lake sediments, which has been validated against a high-resolution record of free gas flux and hydrostatic pressure in Upper Mystic Lake, MA. In contrast to previous linear elastic fracture mechanics analysis of gassy sediments, the evolution of gas transport in a deformable compliant sediment is presented within the framework of multiphase poroplasticity. Experiments address how strongly the mode and rate of gas flow, captured by our model, impacts the size of bubbles released into the water column. A bubble's size in turn determines how efficiently it transports methane to the atmosphere, and integrating this effect will be critical to improving estimates of the atmospheric methane source from lakes. Cross-sectional schematic of lake sediments showing two venting sites: one open at left and one closed at right. The vertical release of gas bubbles (red) at the open venting site creates a local pressure drop, which drives both bubble formation from the methane-rich pore water (higher concentrations shaded darker red) and lateral advection of dissolved methane (purple arrows). Even as bubbles in the open site escape, those at the closed site remain trapped.

  10. A comparison between dispersed nuclear power plants and a nuclear energy center at a hypothetical site on Kentucky Lake, Tennessee. Vol. III. Environmental considerations

    International Nuclear Information System (INIS)

    Fitzpatrick, F.C.; Gray, D.D.; Hyndman, J.R.; Sisman, O.; Suffern, J.S.; Tyrrell, P.A.; West, D.C.

    1976-02-01

    The thermal, ecological, and social impacts of a 40-reactor NEC are compared to impacts from four 10-reactor NECs and ten 4-reactor power plants. The comparison was made for surrogate sites in western Tennessee. The surrogate site for the 40-reactor NEC is located on Kentucky Lake. A layout is postulated for ten clusters of four reactors each with 2.5-mile spacing between clusters. The plants use natural-draft cooling towers. A transmission system is proposed for delivering the power (48,000 MW) to five load centers. Comparable transmission systems are proposed for the 10-reactor NECs and the 4-reactor dispersed sites delivering power to the same load centers.

  11. Earliest Cucurbita from the Great Lakes, Northern USA

    Science.gov (United States)

    Monaghan, G. William; Lovis, William A.; Egan-Bruhy, Kathryn C.

    2006-03-01

    Directly dated Cucurbita from archaeological sites near Lake Huron expand the range and human usage of adventive, cultivated wild gourds or squash into the Great Lakes region, USA, by 4000 14C yr BP. The data also show that domesticated C. pepo squash was cultivated there by 3000 14C yr BP. Although milder Hypsithermal climate may have been a contributing factor, squash and gourds expanded northward during the mid-Holocene mainly by human agency and may be the first human-introduced adventive plant in temperate North America. Even after 3000 14C yr BP, when domesticated squash generally replaced wild varieties at northern sites, squash stands were probably informally managed rather than intensively cultivated.

  12. Hydrology of modern and late Holocene lakes, Death Valley, California

    International Nuclear Information System (INIS)

    Grasso, D.N.

    1996-01-01

    Above-normal precipitation and surface-water runoff, which have been generally related to the cyclic recurrence of the El Nino-Southern Oscillation, have produced modern ephemeral lakes in the closed-basin Death Valley watershed. This study evaluates the regional hydroclimatic relations between precipitation, runoff, and lake transgressions in the Death Valley watershed. Recorded precipitation, runoff, and spring discharge data for the region are used in conjunction with a closed-basin, lake-water-budget equation to assess the relative contributions of water from these sources to modern lakes in Death Valley and to identify the requisite hydroclimatic changes for a late Holocene perennial lake in the valley. As part of the Yucca Mountain Site Characterization Program, an evaluation of the Quaternary regional paleoflood hydrology of the potential nuclear-waste repository site at Yucca Mountain, Nevada, was planned. The objectives of the evaluation were (1) to identify the locations and investigate the hydraulic characteristics of paleofloods and compare these with the locations and characteristics of modern floods, and (2) to evaluate the character and severity of past floods and debris flows to ascertain the potential future hazards to the potential repository during the pre-closure period (US Department of Energy, 1988). This study addresses the first of these objectives, and the second in part, by assessing and comparing the sizes, locations, and recurrence rates of modern, recorded (1962--83) floods and late Holocene paleofloods for the 8,533-mi 2 , closed-basin, Death Valley watershed with its contributing drainage basins in the Yucca Mountain site area

  13. Hydrology of modern and late Holocene lakes, Death Valley, California

    Energy Technology Data Exchange (ETDEWEB)

    Grasso, D.N.

    1996-07-01

    Above-normal precipitation and surface-water runoff, which have been generally related to the cyclic recurrence of the El Nino-Southern Oscillation, have produced modern ephemeral lakes in the closed-basin Death Valley watershed. This study evaluates the regional hydroclimatic relations between precipitation, runoff, and lake transgressions in the Death Valley watershed. Recorded precipitation, runoff, and spring discharge data for the region are used in conjunction with a closed-basin, lake-water-budget equation to assess the relative contributions of water from these sources to modern lakes in Death Valley and to identify the requisite hydroclimatic changes for a late Holocene perennial lake in the valley. As part of the Yucca Mountain Site Characterization Program, an evaluation of the Quaternary regional paleoflood hydrology of the potential nuclear-waste repository site at Yucca Mountain, Nevada, was planned. The objectives of the evaluation were (1) to identify the locations and investigate the hydraulic characteristics of paleofloods and compare these with the locations and characteristics of modern floods, and (2) to evaluate the character and severity of past floods and debris flows to ascertain the potential future hazards to the potential repository during the pre-closure period (US Department of Energy, 1988). This study addresses the first of these objectives, and the second in part, by assessing and comparing the sizes, locations, and recurrence rates of modern, recorded (1962--83) floods and late Holocene paleofloods for the 8,533-mi{sup 2}, closed-basin, Death Valley watershed with its contributing drainage basins in the Yucca Mountain site area.

  14. Baseline risk assessment of ground water contamination at the uranium mill tailings site near Salt Lake City, Utah. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    The Uranium Mill Tailings Remedial Action (UMTRA) Project consists of two phases: the first is the Surface Project, and the second is the Ground Water Project. For the UMTRA Project site known as the Vitro site, near Salt Lake City, Utah, Surface Project cleanup occurred from 1985 to 1987. The UMTRA Project`s second phase, the Ground Water Project, evaluates the nature and extent of ground water contamination resulting from uranium processing and determines a strategy for ground water compliance with the Environmental Protection Agency (EPA) ground water standards established for the UMTRA Project. A risk assessment is the process of describing a source of contamination and showing how that contamination may reach people and the environment. The amount of contamination people or the environment may be exposed to is calculated and used to characterize the possible health or environmental effects that may result from this exposure. This risk assessment report is the first site-specific document prepared for the UMTRA Ground Water Project at the Vitro site. The results of this report and further site characterization of the Vitro site will be used to determine what is necessary, if anything, to protect human health and the environment while complying with EPA standards.

  15. Baseline risk assessment of ground water contamination at the uranium mill tailings site near Salt Lake City, Utah. Revision 1

    International Nuclear Information System (INIS)

    1995-09-01

    The Uranium Mill Tailings Remedial Action (UMTRA) Project consists of two phases: the first is the Surface Project, and the second is the Ground Water Project. For the UMTRA Project site known as the Vitro site, near Salt Lake City, Utah, Surface Project cleanup occurred from 1985 to 1987. The UMTRA Project's second phase, the Ground Water Project, evaluates the nature and extent of ground water contamination resulting from uranium processing and determines a strategy for ground water compliance with the Environmental Protection Agency (EPA) ground water standards established for the UMTRA Project. A risk assessment is the process of describing a source of contamination and showing how that contamination may reach people and the environment. The amount of contamination people or the environment may be exposed to is calculated and used to characterize the possible health or environmental effects that may result from this exposure. This risk assessment report is the first site-specific document prepared for the UMTRA Ground Water Project at the Vitro site. The results of this report and further site characterization of the Vitro site will be used to determine what is necessary, if anything, to protect human health and the environment while complying with EPA standards

  16. Use of wetlands for water quality improvement under the USEPA Region V Clean Lakes Program

    Science.gov (United States)

    Landers, Judith C.; Knuth, Barbara A.

    1991-03-01

    The United States Environmental Protection Agency (USEPA) Region V Clean Lakes Program employs artificial and modified natural wetlands in an effort to improve the water quality of selected lakes. We examined use of wetlands at seven lake sites and evaluated the physical and institutional means by which wetland projects are implemented and managed, relative to USEPA program goals and expert recommendations on the use of wetlands for water quality improvement. Management practices recommended by wetlands experts addressed water level and retention, sheet flow, nutrient removal, chemical treatment, ecological and effectiveness monitoring, and resource enhancement. Institutional characteristics recommended included local monitoring, regulation, and enforcement and shared responsibilities among jurisdictions. Institutional and ecological objectives of the National Clean Lakes Program were met to some degree at every site. Social objectives were achieved to a lesser extent. Wetland protection mechanisms and appropriate institutional decentralization were present at all sites. Optimal management techniques were employed to varying degrees at each site, but most projects lack adequate monitoring to determine adverse ecological impacts and effectiveness of pollutant removal and do not extensively address needs for recreation and wildlife habitat. There is evidence that the wetland projects are contributing to improved lake water quality; however, more emphasis needs to be placed on wetland protection and long-term project evaluation.

  17. Aquatic environmental assessment of Lake Balaton in the light of physical-chemical water parameters.

    Science.gov (United States)

    Sebestyén, Vitkor; Németh, József; Juzsakova, Tatjana; Domokos, Endre; Kovács, Zsófia; Rédey, Ákos

    2017-11-01

    One of the issues of the Hungarian Water Management Strategy is the improvement and upgrading of the water of Lake Balaton. The Water Framework Directive (WFD) specifies and sets forth the achievement of the good ecological status. However, the assessment of the water quality of the lake as a complex system requires a comprehensive monitoring and evaluation procedure. Measurements were carried out around the Lake Balaton at ten different locations/sites and 13 physical-chemical parameters were monitored at each measurement site.For the interpretation of the water chemistry parameters the Aquatic Environmental Assessment (AEA) method devised by authors was used for the water body of the Lake Balaton. The AEA method can be used for all types of the water bodies since it is flexible and using individual weighting procedure for the water chemistry parameters comprehensive information can be obtain. The AEA method was compared with existing EIA methods according to a predefined criterion system and proved to be the most suitable tool for evaluating the environmental impacts in our study.On the basis of the results it can be concluded that the status of the quality of studied area on the Lake Balaton can be categorized as proper quality (from the outcome of the ten measurement sites this conclusion was reached at seven sites).

  18. Measured and modelled trends in European mountain lakes: results of fifteen years of cooperative studies

    Directory of Open Access Journals (Sweden)

    Michela ROGORA

    2004-02-01

    Full Text Available Papers included in this Special Issue of the Journal of Limnology present results of long-term ecological research on mountain lakes throughout Europe. Most of these studies were performed over the last 15 years in the framework of some EU-funded projects, namely AL:PE 1 and 2, MOLAR and EMERGE. These projects together considered a high number of remote lakes in different areas or lake districts in Europe. Central to the projects was the idea that mountain lakes, while subject to the same chemical and biological processes controlling lowland lakes, are more sensitive to any input from their surroundings and can be used as earlywarning indicators of atmospheric pollution and climate change. A first section of this special issue deal with the results of long-term monitoring programmes at selected key-sites. A second section focuse on site-specific and regional applications of an acidification model designed to reconstruct and predict long-term changes in the chemistry of mountain lakes.

  19. Scientific Collaboration on Past Speciation Conditions in Lake Ohrid–SCOPSCO Workshop Report

    Directory of Open Access Journals (Sweden)

    Sasho Trajanovski

    2009-03-01

    Full Text Available Transboundary Lake Ohrid between Albania and Macedonia (SE Europe, Fig. 1 is considered to be the oldest continuously existing lake in Europe with a likely age of three to five million years. The lake has a surface area of 360 km2 and is 289 m deep. An extraordinarily high degree of endemism, including more than 210 described endemic species (Fig. 2, makes the lake a unique aquatic ecosystem of worldwide importance. Due to its old age, Lake Ohrid is one of the very few lakes in the world representing a hot spot of evolution and a potential evolutionary reservoir enabling the survival of relict species (Albrecht and Wilke, 2008. Its importance was emphasized when the lake was declared a UNESCO World Heritage Site in 1979.

  20. Quantifying the Variability of CH4 Emissions from Pan-Arctic Lakes with Lake Biogeochemical and Landscape Evolution Models

    Science.gov (United States)

    Tan, Z.; Zhuang, Q.

    2014-12-01

    Recent studies in the arctic and subarctic show that CH4 emissions from pan-arctic lakes are playing much more significant roles in the regional carbon cycling than previously estimated. Permafrost thawing due to pronounced warming at northern high latitudes affects lake morphology, changing its CH4 emissions. Thermokarst can enlarge the extent of artic lakes, exposing stable ancient carbon buried in the permafrost zone for degradation and changing a previously known carbon sink to a large carbon source. In some areas, the thawing of subarctic discontinuous and isolated permafrost can diminish thermokarst lakes. To date, few models have considered these important hydrological and biogeochemical processes to provide adequate estimation of CH4 emissions from these lakes. To fill this gap, we have developed a process-based climate-sensitive lake biogeochemical model and a landscape evolution model, which have been applied to quantify the state and variability of CH4 emissions from this freshwater system. Site-level experiments show the models are capable to capture the spatial and temporal variability of CH4 emissions from lakes across Siberia and Alaska. With the lake biogeochemical model solely, we estimate that the magnitude of CH4 emissions from lakes is 13.2 Tg yr-1 in the north of 60 ºN at present, which is on the same order of CH4 emissions from northern high-latitude wetlands. The maximum increment is 11.8 Tg CH4 yr-1 by the end of the 21st century when the worst warming scenario is assumed. We expect the landscape evolution model will improve the existing estimates.

  1. The EGU2010 SM1.3 Seismic Centers Data Acquisition session: an introduction to Antelope, EarthWorm and SeisComP, and their use around the World

    Directory of Open Access Journals (Sweden)

    Damiano Pesaresi

    2011-04-01

    Full Text Available Session «SM1.3 - Seismic Centers Data Acquisition» was part of the General Assembly 2010 of the European Geosciences Union (EGU that took place in Vienna (Austria from 2-7 May, 2010. This session was organized to present both the differences and similarities in the operations of different types of seismic data centers, to share the experiences and to stimulate constructive discussion. There are only a few, widely used, "all-in-one" data acquisition and processing packages available for seismic data centers, with two public-domain tools (SeisComP and EarthWorm and one commercial tool (Antelope. The choice of any particular tool will depend on many different criteria, from operational aspects to scientific results, or on the availability of specific requirements in relation to a specific mission. The development of EarthWorm originally started in 1993 in the USA, and it was designed to replace the aging and vendor-tied, regional processing systems. Antelope, started around 1996, with the aim to have real-time data flow from field sensors to scientist. SeisComP also started in the nineties as a real-time data acquisition and processing system, and it evolved towards an early warning system for seismic observatories. Protocols have been established to exchange real-time waveform data between the different packages. In this introductory report, we outline the main characteristics of the three software packages for seismic data acquisition.

  2. Nuclear Energy Center study. Phase II. Site suitability analysis. Final report

    International Nuclear Information System (INIS)

    Fellows, W.S.; Sharp, J.M.; Benator, B.I.

    1978-06-01

    A site screening study was conducted to identify a site or sites for detailed, site-specific study as a nuclear energy center. Using technical criteria of water requirements, geotechnical constraints, and projected load center and transmission considerations as well as environmental and institutional considerations, five potential study sites in the State of South Carolina were identified, evaluated against established criteria, and ranked according to their acceptability as potential nuclear energy center study sites. Consideration of what is ''representative'' of a site as well as the ranking score was factored into site recommendations, since the site deemed easiest to license and permit may not be the most desirable site for future study of the technical and institutional feasibility and practicality of a specific site. The sites near Lake Hartwell and the Savannah River Plant (SRP) of the Department of Energy were selected as potential study sites after consideration of the above criteria. Because the Lake Hartwell site offers the opportunity to consider institutional issues which may be more representative of other possible NEC sites, it is recommended that the Lake Hartwell site be studied to establish the feasibility and practicality of the nuclear energy concept on a site-specific basis

  3. Solar and atmospheric forcing on mountain lakes.

    Science.gov (United States)

    Luoto, Tomi P; Nevalainen, Liisa

    2016-10-01

    We investigated the influence of long-term external forcing on aquatic communities in Alpine lakes. Fossil microcrustacean (Cladocera) and macrobenthos (Chironomidae) community variability in four Austrian high-altitude lakes, determined as ultra-sensitive to climate change, were compared against records of air temperature, North Atlantic Oscillation (NAO) and solar forcing over the past ~400years. Summer temperature variability affected both aquatic invertebrate groups in all study sites. The influence of NAO and solar forcing on aquatic invertebrates was also significant in the lakes except in the less transparent lake known to have remained uniformly cold during the past centuries due to summertime snowmelt input. The results suggest that external forcing plays an important role in these pristine ecosystems through their impacts on limnology of the lakes. Not only does the air temperature variability influence the communities but also larger-scale external factors related to atmospheric circulation patterns and solar activity cause long-term changes in high-altitude aquatic ecosystems, through their connections to hydroclimatic conditions and light environment. These findings are important in the assessment of climate change impacts on aquatic ecosystems and in greater understanding of the consequences of external forcing on lake ontogeny. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Alaska Open-file Report 144 Assessment of Thermal Springs Sites Aleutian Arc, Atka Island to Becherof Lake -- Preliminary Results and Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Motyka, R.J.; Moorman, M.A.; Liss, S.A.

    1981-12-01

    Twenty of more than 30 thermal spring areas reported to exist in the Aleutian arc extending from Atka Island to Becherof Lake were investigated during July and August, 1980. Thermal activity of three of these sites had diminished substantially or no longer existed. At least seven more sites where thermal-spring activity is probable or certain were not visited because of their remoteness or because of time constraints. The existence of several other reported thermal spring sites could not be verified; these sites are considered questionable. On the basis of geothermometry, subsurface reservoir temperatures in excess of 150 C are estimated for 10 of the thermal spring sites investigated. These sites all occur in or near regions of Recent volcanism. Five of the sites are characterized by fumaroles and steaming ground, indicating the presence of at least a shallow vapor-dominated zone. Two, the Makushin Valley and Glacier Valley thermal areas, occur on the flanks of active Mukushin Volcano located on Unalaska Island, and may be connected to a common source of heat. Gas geothermometry suggests that the reservoir feeding the Kliuchef thermal field, located on the flanks of Kliuchef volcano of northeast Atka Island, may be as high as 239 C.

  5. Catchment tracers reveal discharge, recharge and sources of groundwater-borne pollutants in a novel lake modelling approach

    Directory of Open Access Journals (Sweden)

    E. Kristensen

    2018-02-01

    Full Text Available Groundwater-borne contaminants such as nutrients, dissolved organic carbon (DOC, coloured dissolved organic matter (CDOM and pesticides can have an impact the biological quality of lakes. The sources of pollutants can, however, be difficult to identify due to high heterogeneity in groundwater flow patterns. This study presents a novel approach for fast hydrological surveys of small groundwater-fed lakes using multiple groundwater-borne tracers. Water samples were collected from the lake and temporary groundwater wells, installed every 50 m within a distance of 5–45 m to the shore, were analysed for tracer concentrations of CDOM, DOC, total dissolved nitrogen (TDN, groundwater only, total nitrogen (TN, lake only, total dissolved phosphorus (TDP, groundwater only, total phosphorus (TP, lake only, δ18O ∕ δ16O isotope ratios and fluorescent dissolved organic matter (FDOM components derived from parallel factor analysis (PARAFAC. The isolation of groundwater recharge areas was based on δ18O measurements and areas with a high groundwater recharge rate were identified using a microbially influenced FDOM component. Groundwater discharge sites and the fractions of water delivered from the individual sites were isolated with the Community Assembly via Trait Selection model (CATS. The CATS model utilized tracer measurements of TDP, TDN, DOC and CDOM from the groundwater samples and related these to the tracer measurements of TN, TP, DOC and CDOM in the lake. A direct comparison between the lake and the inflowing groundwater was possible as degradation rates of the tracers in the lake were taken into account and related to a range of water retention times (WRTs of the lake (0.25–3.5 years in 0.25-year increments. These estimations showed that WRTs above 2 years required a higher tracer concentration of inflowing water than found in any of the groundwater wells around the lake. From the estimations of inflowing tracer concentration

  6. Terrestrial CDOM in Lakes of Yamal Peninsula: Connection to Lake and Lake Catchment Properties

    Directory of Open Access Journals (Sweden)

    Yury Dvornikov

    2018-01-01

    Full Text Available In this study, we analyze interactions in lake and lake catchment systems of a continuous permafrost area. We assessed colored dissolved organic matter (CDOM absorption at 440 nm (a(440CDOM and absorption slope (S300–500 in lakes using field sampling and optical remote sensing data for an area of 350 km2 in Central Yamal, Siberia. Applying a CDOM algorithm (ratio of green and red band reflectance for two high spatial resolution multispectral GeoEye-1 and Worldview-2 satellite images, we were able to extrapolate the a(λCDOM data from 18 lakes sampled in the field to 356 lakes in the study area (model R2 = 0.79. Values of a(440CDOM in 356 lakes varied from 0.48 to 8.35 m−1 with a median of 1.43 m−1. This a(λCDOM dataset was used to relate lake CDOM to 17 lake and lake catchment parameters derived from optical and radar remote sensing data and from digital elevation model analysis in order to establish the parameters controlling CDOM in lakes on the Yamal Peninsula. Regression tree model and boosted regression tree analysis showed that the activity of cryogenic processes (thermocirques in the lake shores and lake water level were the two most important controls, explaining 48.4% and 28.4% of lake CDOM, respectively (R2 = 0.61. Activation of thermocirques led to a large input of terrestrial organic matter and sediments from catchments and thawed permafrost to lakes (n = 15, mean a(440CDOM = 5.3 m−1. Large lakes on the floodplain with a connection to Mordy-Yakha River received more CDOM (n = 7, mean a(440CDOM = 3.8 m−1 compared to lakes located on higher terraces.

  7. Multi-contamination (heavy metals, polychlorinated biphenyls and polycyclic aromatic hydrocarbons) of littoral sediments and the associated ecological risk assessment in a large lake in France (Lake Bourget).

    Science.gov (United States)

    Lécrivain, Nathalie; Aurenche, Vincent; Cottin, Nathalie; Frossard, Victor; Clément, Bernard

    2018-04-01

    The lake littoral sediment is exposed to a large array of contaminants that can exhibit significant spatial variability and challenge our ability to assess contamination at lake scale. In this study, littoral sediment contamination was characterized among ten different sites in a large peri-alpine lake (Lake Bourget) regarding three groups of contaminants: 6 heavy metals, 15 polycyclic aromatic hydrocarbons and 7 polychlorinated biphenyls. The contamination profiles significantly varied among sites and differed from those previously reported for the deepest zone of the lake. An integrative approach including chemical and biological analyses was conducted to relate site contamination to ecological risk. The chemical approach consisted in mean PEC quotient calculation (average of the ratios of the contaminants concentration to their corresponding Probable Effect Concentration values) and revealed a low and heterogeneous toxicity of the contaminant mixture along the littoral. Biological analysis including both laboratory (microcosm assays) and in situ (Acetylcholine Esterase (AChE) and Glutathione S-Transferase (GST) activity measurements) experiments highlighted significant differences among sites both in the field and in laboratory assays suggesting a spatial variation of the biota response to contamination. Linear regressions were performed between mean PEC quotients and biological results to assess whether littoral ecological risk was explained by the contamination profiles. The results highly depended on the study benthic or pelagic compartment. Regarding autochthonous Corbicula fluminea, no significant relationship between mean PEC quotients and biomarker activity was found while a significant increase in AChE was observed on autochthonous chironomids, suggesting different stress among benthic organisms. Both AChE and GST in caged pelagic Daphnia magna showed a significant positive relationship with mean PEC quotients. This study underlines the importance of

  8. Summary of the Phase II, Title I engineering assessment of inactive uranium mill tailings, Phillips/United Nuclear Site, Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    1977-12-01

    An engineering assessment was performed of the problems resulting from the existence of radioactive uranium mill tailings at the Phillips/United Nuclear site at Ambrosia Lake, New Mexico. Services included the preparation of topographic maps, the performance of core drillings sufficient to determine areas and volumes of tailings and radiometric measurements to determine radium-contaminated materials, the evaluation of resulting radiation exposures of individuals and nearby populations, the investigation of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas release from the 2.6 million tons of tailings at the Phillips/United Nuclear site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation are also factors. The estimated radiological health effects to the general population are considered to be minimal. The two alternative actions presented are: dike stabilization, fencing, and maintenance; and adding 2 ft of stabilization cover material. Both options include remedial action at off-site structures and on-site decontamination around the tailings pile. Cost estimates for the two options are $920,000 and $2,230,000, respectively

  9. Estimating the recreational value of Pakistan's largest freshwater lake to support sustainable tourism management using a travel cost model

    NARCIS (Netherlands)

    Mangan, T.; Brouwer, R.; Lohano, H.; Nagraj, G.M.

    2013-01-01

    Keenjhar Lake, Pakistan's largest freshwater lake and an important Ramsar site, provides habitat for internationally important water birds. Annually, 385,000 people visit the lake. The lake is threatened by a variety of causes, including industrial and agricultural pollution. To support its

  10. Carbonaceous particle record in lake sediments from the Arctic and other remote areas of the northern hemisphere

    International Nuclear Information System (INIS)

    Rose, N.L.

    1995-01-01

    Lake sediments, including spheroidal carbonaceous particles produced by high temperature combustion of fossil fuels, contain a record of lake, catchment and atmospheric deposition history. The spatial and temporal distributions of these particles can indicate the extent to which a single lake or a region has been contaminated by airborne pollutants (e.g. sulfur, polycyclic aromatic hydrocarbons (PAHs)) derived from fossil fuels. The carbonaceous particle records of two Arctic lakes, Shuonijavr and Stepanovichjarvi, close to local pollution sources on the Kola Peninsula, Russia, are compared with the record of a remote lake on Svalbard and with mid-latitude remote mountain lakes in Europe and Asia. Although, Shuonijavr and Stepanovichjarvi show relatively high levels of contamination, as expected, the presence of carbonaceous particles at all of the remote sites studied suggests there is a hemispherical background of these particles. Other less remote mountain lakes in Europe have been found to contain significant concentrations of particles and these may represent regional deposition patterns. Carbonaceous particle analysis may provide an effective assessment of whether a lake site is receiving local, regional or background levels of deposition

  11. An ecohydrological-based management of Lake Beratan in Bedugul, Bali

    Science.gov (United States)

    Atmaja, D. M.; Budiastuti, M. S.; Setyono, P.; Sunarto

    2018-04-01

    Lake Beratan is one of waterway ecosystems located in the upper land of Bedugul, Bali and has become a tourist object which is visited by many foreign as well as domestic tourists. This is supported by a sufficiently high economic growth which, without the community’s being aware of, has caused environmental problems such as the shallowing of the lake, erosion, and water pollution to such an extent that have resulted in the degradation of the function of the lake as the site of catchment. The degradation of the function of the lake can be overcome by ecohydrological-based management. This study was aimed at developing an integrated and long lasting Lake Beratan environment management concept. The study used a descriptive qualitative approach using a survey, by collecting primary and secondary data. On the basis of those data the mapping of the potentials of the lake and problems of the lake which were then integrated to formulate criteria for sustainable use of Lake Beratan waters environment resources. The determination of zonation of the lake was done based on those criteria and the community’s existence consideration as well as the exising system of the lake waterway environment use. Based on the study in the field, some recommendations could be made concerning Lake Beratan waterway sustainable and integrated management.

  12. Modeling Lake Storage Dynamics to support Arctic Boreal Vulnerability Experiment (ABoVE)

    Science.gov (United States)

    Vimal, S.; Lettenmaier, D. P.; Smith, L. C.; Smith, S.; Bowling, L. C.; Pavelsky, T.

    2017-12-01

    The Arctic and Boreal Zone (ABZ) of Canada and Alaska includes vast areas of permafrost, lakes, and wetlands. Permafrost thawing in this area is expected to increase due to the projected rise of temperature caused by climate change. Over the long term, this may reduce overall surface water area, but in the near-term, the opposite is being observed, with rising paludification (lake/wetland expansion). One element of NASA's ABoVE field experiment is observations of lake and wetland extent and surface elevations using NASA's AirSWOT airborne interferometric radar, accompanied by a high-resolution camera. One use of the WSE retrievals will be to constrain model estimates of lake storage dynamics. Here, we compare predictions using the lake dynamics algorithm within the Variable Infiltration Capacity (VIC) land surface scheme. The VIC lake algorithm includes representation of sub-grid topography, where the depth and area of seasonally-flooded areas are modeled as a function of topographic wetness index, basin area, and slope. The topography data used is from a new global digital elevation model, MERIT-DEM. We initially set up VIC at sites with varying permafrost conditions (i.e., no permafrost, discontinuous, continuous) in Saskatoon and Yellowknife, Canada, and Toolik Lake, Alaska. We constrained the uncalibrated model with the WSE at the time of the first ABoVE flight, and quantified the model's ability to predict WSE and ΔWSE during the time of the second flight. Finally, we evaluated the sensitivity of the VIC-lakes model and compared the three permafrost conditions. Our results quantify the sensitivity of surface water to permafrost state across the target sites. Furthermore, our evaluation of the lake modeling framework contributes to the modeling and mapping framework for lake and reservoir storage change evaluation globally as part of the SWOT mission, planned for launch in 2021.

  13. Converting the Key Lake mill process for McArthur River ore

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, C. [McArthur River Operation, Cameco Corporation, Saskatoon, Saskatchewan (Canada)

    2000-07-01

    The Key Lake mill was commissioned in 1983 to process the two Key Lake ore deposits. With the depletion of these ore bodies in 1999, the plant was converted to mill the exceptionally rich McArthur River deposit located seventy eight kilometers northeast of the Key Lake mine site. This paper describes in detail the Key Lake milling process. The mill consists of a grinding circuit, a leach/counter current decantation circuit, a solvent extraction circuit, a yellowcake precipitation/calciner circuit, an ammonium sulphate crystallization circuit, and a waste treatment circuit. The paper also describes process changes to handle McArthur River ore, including the ore receiving station. (author)

  14. Toxicological evaluation of a lake ecosystem contaminated with crude oil

    International Nuclear Information System (INIS)

    Twigg, D.; Ramey, B.

    1995-01-01

    Winona Lake on the Daniel Boone National Forest in Powell County, Kentucky, was used from the mid 1950's to 1987 as a water source for water-injection oil drilling and as a brine disposal site. The lake was contaminated with excessive amounts of crude oil. A multi phase investigation was conducted, including chemical analysis of water and sediment, water toxicity tests using a cladoceran, Ceriodaphnia dubia, sediment toxicity tests using an amphipod, Hyalella azteca, and a faunal survey of the communities of the lake and stream both above and below the lake. The sediment was laden with petroleum hydrocarbons (4.1 parts per thousand), while the water showed no contamination. The C dubia test results showed no significant water toxicity. The contaminated sediment adjacent to the dam produced 75% mortality in H. azteca. The faunal survey indicated little or no impact on the upstream and downstream communities but the lake community was highly impacted, especially the benthos. Pollution tolerant Chaoborus sp. were the only organisms collected from sediment samples dredged from the lake. Contamination was limited to the sediment within the lake but the impact on the entire lake community was severe

  15. Lake-level variation in the Lahontan basin for the past 50,000 years

    Science.gov (United States)

    Benson, L.V.; Thompson, R.S.

    1987-01-01

    Selected radiocarbon data on surficial materials from the Lahontan basin, Nevada and California, provide a chronology of lake-level variation for the past 50,000 yr. A moderate-sized lake connected three western Lahontan subbasins (the Smoke Creek-Black Rock Desert subbasin, the Pyramid Lake subbasin, and the Winnemucca Dry Lake subbasin) from about 45,000 to 16,500 yr B.P. Between 50,000 and 45,000 yr B.P., Walker Lake rose to its sill level in Adrian Valley and spilled to the Carson Desert subbasin. By 20,000 yr B.P., lake level in the western Lahontan subbasins had risen to about 1265 m above sea level, where it remained for 3500 yr. By 16,000 yr B.P., lake level in the western Lahontan subbasins had fallen to 1240 m. This recession appears synchronous with a desiccation of Walker Lake; however, whether the Walker Lake desiccation resulted from climate change or from diversion of the Walker River is not known. From about 15,000 to 13,500 yr B.P., lake level rapidly rose, so that Lake Lahontan was a single body of water by 14,000 yr B.P. The lake appears to have reached a maximum highstand altitude of 1330 m by 13,500 yr B.P., a condition that persisted until about 12,500 yr B.P., at which time lake level fell ???100 m. No data exist that indicate the level of lakes in the various subbasins between 12,000 and 10,000 yr B.P. During the Holocene, the Lahontan basin was the site of shallow lakes, with many subbasins being the site of one or more periods of desiccation. The shape of the lake-level curve for the three western subbasins indicates that past changes in the hydrologic balance (and hence climate) of the Lahontan basin were large in magnitude and took place in a rapid step-like manner. The rapid changes in lake level are hypothesized to have resulted from changes in the mean position of the jet stream, as it was forced north or south by the changing size and shape of the continental ice sheet. ?? 1987.

  16. Water-quality and bottom-material characteristics of Cross Lake, Caddo Parish, Louisiana, 1997-99

    Science.gov (United States)

    McGee, Benton D.

    2004-01-01

    Cross Lake is a shallow, monomictic lake that was formed in 1926 by the impoundment of Cross Bayou. The lake is the primary drinking-water supply for the City of Shreveport, Louisiana. In recent years, the lakeshore has become increasinginly urbanized. In addition, the land use of the watershed contributing runoff to Cross Lake has changed. Changes in land use and urbanization could affect the water chemistry and biology of the Lake. Water-quality data were collected at 10 sites on Cross Lake from February 1997 to February 1999. Water-column and bottom-material samples were collected. The water-column samples were collected at least four times per year. These samples included physical and chemical-related properties such as water temperature, dissolved oxygen, pH, and specific conductance; selected major inorganic ions; nutrients; minor elements; organic chemical constituents; and bacteria. Suspended-sediment samples were collected seven times during the sampling period. The bottom-material samples, which were collected once during the sampling period, were analyzed for selected minor elements and inorganic carbon. Aside from the nutrient-enriched condition of Cross Lake, the overall water-quality of Cross Lake is good. No primary Federal or State water-quality criteria were exceeded by any of the water-quality constituents analyzed for this report. Concentrations of major inorganic constituents, except iron and manganese, were low. Water from the lake is a sodium-bicarbonate type and is soft. Minor elements and organic compounds were present in low concentrations, many below detection limits. Nitrogen and phosphorus were the nutrients occurring in the highest concentrations. Nutrients were evenly distributed across the lake with no particular water-quality site indicating consistently higher or lower nutrient concentrations. No water samples analyzed for nitrate exceeded the U.S. Environmental Protection Agency's Maximum Contaminant Level of 10 milligrams per

  17. Sanctuaries for lake trout in the Great Lakes

    Science.gov (United States)

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

    1987-01-01

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

  18. An improved active contour model for glacial lake extraction

    Science.gov (United States)

    Zhao, H.; Chen, F.; Zhang, M.

    2017-12-01

    Active contour model is a widely used method in visual tracking and image segmentation. Under the driven of objective function, the initial curve defined in active contour model will evolve to a stable condition - a desired result in given image. As a typical region-based active contour model, C-V model has a good effect on weak boundaries detection and anti noise ability which shows great potential in glacial lake extraction. Glacial lake is a sensitive indicator for reflecting global climate change, therefore accurate delineate glacial lake boundaries is essential to evaluate hydrologic environment and living environment. However, the current method in glacial lake extraction mainly contains water index method and recognition classification method are diffcult to directly applied in large scale glacial lake extraction due to the diversity of glacial lakes and masses impacted factors in the image, such as image noise, shadows, snow and ice, etc. Regarding the abovementioned advantanges of C-V model and diffcults in glacial lake extraction, we introduce the signed pressure force function to improve the C-V model for adapting to processing of glacial lake extraction. To inspect the effect of glacial lake extraction results, three typical glacial lake development sites were selected, include Altai mountains, Centre Himalayas, South-eastern Tibet, and Landsat8 OLI imagery was conducted as experiment data source, Google earth imagery as reference data for varifying the results. The experiment consequence suggests that improved active contour model we proposed can effectively discriminate the glacial lakes from complex backgound with a higher Kappa Coefficient - 0.895, especially in some small glacial lakes which belongs to weak information in the image. Our finding provide a new approach to improved accuracy under the condition of large proportion of small glacial lakes and the possibility for automated glacial lake mapping in large-scale area.

  19. Nuclear Energy Center study. Phase II. Site suitability analysis. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Fellows, W.S.; Sharp, J.M.; Benator, B.I.

    1978-06-01

    A site screening study was conducted to identify a site or sites for detailed, site-specific study as a nuclear energy center. Using technical criteria of water requirements, geotechnical constraints, and projected load center and transmission considerations as well as environmental and institutional considerations, five potential study sites in the State of South Carolina were identified, evaluated against established criteria, and ranked according to their acceptability as potential nuclear energy center study sites. Consideration of what is ''representative'' of a site as well as the ranking score was factored into site recommendations, since the site deemed easiest to license and permit may not be the most desirable site for future study of the technical and institutional feasibility and practicality of a specific site. The sites near Lake Hartwell and the Savannah River Plant (SRP) of the Department of Energy were selected as potential study sites after consideration of the above criteria. Because the Lake Hartwell site offers the opportunity to consider institutional issues which may be more representative of other possible NEC sites, it is recommended that the Lake Hartwell site be studied to establish the feasibility and practicality of the nuclear energy concept on a site-specific basis.

  20. Methane emission by bubbling from Gatun Lake, Panama

    Science.gov (United States)

    Keller, Michael; Stallard, Robert F.

    1994-01-01

    We studied methane emission by bubbling from Gatun Lake, Panama, at water depths of less than 1 m to about 10 m. Gas bubbles were collected in floating traps deployed during 12- to 60-hour observation periods. Comparison of floating traps and floating chambers showed that about 98% of methane emission occurred by bubbling and only 2% occurred by diffusion. Average methane concentration of bubbles at our sites varied from 67% to 77%. Methane emission by bubbling occurred episodically, with greatest rates primarily between the hours of 0800 and 1400 LT. Events appear to be triggered by wind. The flux of methane associated with bubbling was strongly anticorrelated with water depth. Seasonal changes in water depth caused seasonal variation of methane emission. Bubble methane fluxes through the lake surface into the atmosphere measured during 24-hour intervals were least (10-200 mg/m2/d) at deeper sites (greater than 7 m) and greatest (300-2000 mg/m2/d) at shallow sites (less than 2 m).

  1. Phytoplankton composition of Sazlidere Dam lake, Istanbul, Turkey

    Directory of Open Access Journals (Sweden)

    Nese Yilmaz

    2013-05-01

    Full Text Available The phytoplankton composition of Sazlidere Dam lake was studied at 5 sampling sites between December 2003 - November 2005. A total of 67 taxa were recorded, representing Bacillariophyta (31, Chlorophyta (18, Cyanophyta (9, Chrysophyta (1, Cryptophyta (1, Dinophyta (3 and Euglenophyta (4. Bacillariophyta members constituted the dominant phytoplankton group in terms of species number. Nygaard’s compound index value and composition of phytoplankton indicate that the trophic state of Sazlidere Dam lake was changing from oligotrophic to mesotrophic.

  2. Hydrologic and Water-Quality Characterization and Modeling of the Onondaga Lake Basin, Onondaga County, New York

    Science.gov (United States)

    Coon, William F.; Reddy, James E.

    2008-01-01

    Onondaga Lake in Onondaga County, New York, has been identified as one of the Nation?s most contaminated lakes as a result of industrial and sanitary-sewer discharges and stormwater nonpoint sources, and has received priority cleanup status under the national Water Resources Development Act of 1990. A basin-scale precipitation-runoff model of the Onondaga Lake basin was identified as a desirable water-resources management tool to better understand the processes responsible for the generation of loads of sediment and nutrients that are transported to Onondaga Lake. During 2003?07, the U.S. Geological Survey (USGS) developed a model based on the computer program, Hydrological Simulation Program?FORTRAN (HSPF), which simulated overland flow to, and streamflow in, the major tributaries of Onondaga Lake, and loads of sediment, phosphorus, and nitrogen transported to the lake. The simulation period extends from October 1997 through September 2003. The Onondaga Lake basin was divided into 107 subbasins and within these subbasins, the land area was apportioned among 19 pervious and impervious land types on the basis of land use and land cover, hydrologic soil group (HSG), and aspect. Precipitation data were available from three sources as input to the model. The model simulated streamflow, water temperature, concentrations of dissolved oxygen, and concentrations and loads of sediment, orthophosphate, total phosphorus, nitrate, ammonia, and organic nitrogen in the four major tributaries to Onondaga Lake?Onondaga Creek, Harbor Brook, Ley Creek, and Ninemile Creek. Simulated flows were calibrated to data from nine USGS streamflow-monitoring sites; simulated nutrient concentrations and loads were calibrated to data collected at six of the nine streamflow-monitoring sites. Water-quality samples were collected, processed, and analyzed by personnel from the Onondaga County Department of Water Environment Protection. Several time series of flow, and sediment and nutrient loads

  3. Evolution of alkaline lakes - Lake Van case study

    Science.gov (United States)

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

    2017-04-01

    Lake Van in Eastern Anatolia (Turkey) is the largest terminal soda lake on Earth. The lake sedimentary profile covers ca. 600 ka (Stockhecke et al. 2014) Based on lithological changes, the presence of freshwater microfossils and close-to-freshwater pH value in the pore water, members of ICDP PALEOVAN concluded that Lake Van might have started as an open lake. Here we show paleontological and geochemical evidence in favour of this idea and constrain the time, when Lake Van likely transformed into a closed lake. Additionally we provide the first conceptual model of how this closure may have happened. Our archives of choice are inorganic and biogenic carbonates, separated by wet sieving. We identified microfossil assemblages (fraction > 125 µm) and performed high-resolution oxygen isotope (delta18O) and elemental (Mg/Ca, Sr/Ca) analyses of the fraction plants growing in the photic zone as food supply. These two aspects point to an increasing salinity in a shallowing lake. The delta18O values of inorganic carbonates are relatively low during the initial phase of Lake Van and increase abruptly (ca. 7‰) after 530 ka BP. At approximately the same time combination of Sr/Ca and Mg/Ca data suggest first occurrence of aragonite. Again, these findings suggest geochemical changes of the lake water concurrent with transition documented by microfossils. Comparison between Lake Van and Lake Ohrid (Lacey et al. 2016) delta18O data, precludes regional climate change (e.g.: increased evaporation) as the main driver of observed changes. With no evidence for increased volcanic or tectonic activity (e.g.: tephra layers, deformation structures, slumping) in the Lake Van sedimentary profile around 530 ka, it seems unlikely that a pyroclastic flow blocked the outflow of the lake. Alternatively, a portion of inflow has been diverged which might have caused a change in the hydrological balance and lake level falling below its outlet. However, as no geomorphological data confirming this

  4. Characterization of habitat and biological communities at fixed sites in the Great Salt Lake basins, Utah, Idaho, and Wyoming, water years 1999-2001

    Science.gov (United States)

    Albano, Christine M.; Giddings, Elise M.P.

    2007-01-01

    Habitat and biological communities were sampled at 10 sites in the Great Salt Lake Basins as part of the U.S. Geological Survey National Water-Quality Assessment program to assess the occurrence and distribution of biological organisms in relation to environmental conditions. Sites were distributed among the Bear River, Weber River, and Utah Lake/Jordan River basins and were selected to represent stream conditions in different land-use settings that are prominent within the basins, including agriculture, rangeland, urban, and forested.High-gradient streams had more diverse habitat conditions with larger substrates and more dynamic flow characteristics and were typically lower in discharge than low-gradient streams, which had a higher degree of siltation and lacked variability in geomorphic channel characteristics, which may account for differences in habitat. Habitat scores were higher at high-gradient sites with high percentages of forested land use within their basins. Sources and causes of stream habitat impairment included effects from channel modifications, siltation, and riparian land use. Effects of hydrologic modifications were evident at many sites.Algal sites where colder temperatures, less nutrient enrichment, and forest and rangeland uses dominated the basins contained communities that were more sensitive to organic pollution, siltation, dissolved oxygen, and salinity than sites that were warmer, had higher degrees of nutrient enrichment, and were affected by agriculture and urban land uses. Sites that had high inputs of solar radiation and generally were associated with agricultural land use supported the greatest number of algal species.Invertebrate samples collected from sites where riffles were the richest-targeted habitat differed in species composition and pollution tolerance from those collected at sites that did not have riffle habitat (nonriffle sites), where samples were collected in depositional areas, woody snags, or macrophyte beds

  5. Bathymetry of Lake Erie and Lake Saint Clair

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Erie and Lake Saint Clair has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and...

  6. Key Lake mine water spill: further clean-up not required

    International Nuclear Information System (INIS)

    Potvin, R.

    1984-02-01

    The Atomic Energy Control Board (AECB) has concluded that no additional remedial measures are warranted with regard to the mine water spill which occurred in early January at the Key Lake Mining Corporation facility in northern Saskatchewan, and has advised the company to reconsider its proposal for clean-up of the adjoining Gerald Lake basin. On January 5, an estimated 87 million litres of mine water was accidentally released to the environment when a water storage reservoir at the mine site overflowed. The spilled water flowed into the adjoining Gerald Lake catchment area where it has remained adequately contained

  7. Annual variation in polychlorinated biphenyl (PCB) exposure in tree swallow (Tachycineta bicolor) eggs and nestlings at Great Lakes Restoration Initiative (GLRI) study sites

    Science.gov (United States)

    Custer, Christine M.; Custer, Thomas W.; Dummer, Paul; Goldberg, Diana R.; Franson, J. Christian

    2018-01-01

    Tree swallow (Tachycineta bicolor) eggs and nestlings were collected from 16 sites across the Great Lakes to quantify normal annual variation in total polychlorinated biphenyl (PCB) exposure and to validate the sample size choice in earlier work. A sample size of five eggs or five nestlings per site was adequate to quantify exposure to PCBs in tree swallows given the current exposure levels and variation. There was no difference in PCB exposure in two randomly selected sets of five eggs collected in the same year, but analyzed in different years. Additionally, there was only modest annual variation in exposure, with between 69% (nestlings) and 73% (eggs) of sites having no differences between years. There was a tendency, both statistically and qualitatively, for there to be less exposure in the second year compared to the first year.

  8. Sediment pollution in margins of the Lake Guaíba, Southern Brazil.

    Science.gov (United States)

    de Andrade, Leonardo Capeleto; Tiecher, Tales; de Oliveira, Jessica Souza; Andreazza, Robson; Inda, Alberto Vasconcellos; de Oliveira Camargo, Flávio Anastácio

    2017-12-02

    Sediments are formed by deposition of organic and inorganic particles on depth of water bodies, being an important role in aquatic ecosystems, including destination and potential source of essential nutrients and heavy metals, which may be toxic for living organisms. The Lake Guaíba supplies water for approximately two million people and it is located in the metropolitan region of Porto Alegre, Rio Grande do Sul State, Brazil. Thus, the aim of this study was to evaluate the sediment pollution in the margins of Lake Guaíba in the vicinity of Porto Alegre city. Surface sediment was sampled in 12 sites to assess the concentration of several elements (C, N, P, Fe, Al, Ca, Mg, Na, K, Mn, Ba, Zn, V, Pb, Cu, Cr, Ni, Cd, Mo, and Se) and the mineralogical composition. Sediment in margins of Lake Guaíba presented predominantly (> 95%) sandy fraction in all samples, but with significant differences between evaluated sites. Sediments in the margins of Lake Guaíba showed indications of punctual water pollution with Pb, Cu, Cr, Ni, TOC, TKN, and P, mainly derived from urban streams that flow into the lake. In order to solve these environmental liabilities, public actions should not focus only on Guaíba, but also in the streams that flow into the lake.

  9. REGULARITIES OF CONGELATION ICE DEVELOPMENT IN SUBGLACIAL LAKE VOSTOK

    Directory of Open Access Journals (Sweden)

    V. Ya. Lipenkov

    2012-01-01

    Full Text Available Petrographic studies performed on the continuous basis along the two ice cores obtained from holes 5G-1 and 5G-2 at Vostok Station has allowed to characterize with great details the evolution of the ice texture and fabric in the 232-m thick stratum of accreted ice formed from theLakeVostokwater. Conventionally the whole thickness of accreted ice is divided into two strata: lake ice 1 and lake ice 2. Lake ice 1 (3537–3618 m, formed in the sallow strait50 kmupstream of Vostok, is characterized by presence of disseminated mineral inclusions of Lake Vostok sediments, as well as of «water pockets» that represent frozen water inclusions trapped during the ice accretion. The latter constitute less than 1% of the total ice volume, their mean size is about0.5 cm. Gases trapped by «water pockets» during ice formation transform into crystalline inclusions of mixed gas hydrates. Accretion of lake ice 2 (3618–3769 m proceeds in the deep part of the lake at a very small rate that does not assume trapping of liquid water inclusions and gases.Both strata of accreted ice are formed by orthotropic crystal growth from pure water. The main tendency in the evolution of accreted ice texture is growth of the mean crystal size with depth as the lake ice becomes younger towards the ice-water interface. The high-amplitude variations of crystal size and orientation observed around this general trend are shown to be linked with temporal and spatial variability of the supercooled melt-water flux from the northern part of the lake towards the ice formation site. The presence of supercooled water at the crystallization front supports persistent preferable growth of ice crystals with sub-horizontally oriented c-axes. The lack of supercooled water in turn support persistent growth of ice crystals with vertical or inclined with respect to the crystallization front c-axis orientation. It means that each of these preferred fabric orientations could serve as an indicator of

  10. Preliminary Study of the Effect of the Proposed Long Lake Valley Project Operation on the Transport of Larval Suckers in Upper Klamath Lake, Oregon

    Science.gov (United States)

    Wood, Tamara M.

    2009-01-01

    A hydrodynamic model of Upper Klamath and Agency Lakes, Oregon, was used to explore the effects of the operation of proposed offstream storage at Long Lake Valley on transport of larval suckers through the Upper Klamath and Agency Lakes system during May and June, when larval fish leave spawning sites in the Williamson River and springs along the eastern shoreline and become entrained in lake currents. A range in hydrologic conditions was considered, including historically high and low outflows and inflows, lake elevations, and the operation of pumps between Upper Klamath Lake and storage in Long Lake Valley. Two wind-forcing scenarios were considered: one dominated by moderate prevailing winds and another dominated by a strong reversal of winds from the prevailing direction. On the basis of 24 model simulations that used all combinations of hydrology and wind forcing, as well as With Project and No Action scenarios, it was determined that the biggest effect of project operations on larval transport was the result of alterations in project management of the elevation in Upper Klamath Lake and the outflow at the Link River and A Canal, rather than the result of pumping operations. This was because, during the spring time period of interest, the amount of water pumped between Upper Klamath Lake and Long Lake Valley was generally small. The dominant effect was that an increase in lake elevation would result in more larvae in the Williamson River delta and in Agency Lake, an effect that was enhanced under conditions of wind reversal. A decrease in lake elevation accompanied by an increase in the outflow at the Link River had the opposite effect on larval concentration and residence time.

  11. Lake Urmia (Iran): can future socio-ecologically motivated river basin management restore lake water levels in an arid region with extensive agricultural development?

    Science.gov (United States)

    Fazel, Nasim; Berndtsson, Ronny; Bertacchi Uvo, Cintia; Klove, Bjorn; Madani, Kaveh

    2015-04-01

    Lake Urmia, one of the world's largest hyper saline lakes located in northwest of Iran, is a UNESCO Biosphere Reserve and Ramsar site, protected as a national park and, supports invaluable and unique biodiversity and related ecosystem services for the region's 6.5 million inhabitants. Due to increased development of the region's water resources for agriculture and industry and to a certain extent climate change, the lake has started to shrink dramatically since 1995 and now is holding less than 30 percent of its volume. Rapid development in agricultural sector and land-use changes has resulted in immense construction of dams and water diversions in almost all lake feeding rivers, intensifying lake shrinking, increasing salinity and degrading its ecosystem. Recently, lake's cultural and environmental importance and social pressure has raised concerns and brought government attention to the lake restoration plans. Along with poor management, low yield agriculture as the most water consuming activity in the region with, rapid, insufficient development is one of the most influential drivers in the lake desiccation. Part of the lake restoration plans in agricultural sector is to restrict the agricultural areas in the main feeding river basins flowing mostly in the southern part of the lake and decreasing the agricultural water use in this area. This study assess the efficiency and effectiveness of the proposed plans and its influence on the lake level rise and its impacts on economy in the region using a system dynamics model developed for the Lake consist of hydrological and agro-economical sub-systems. The effect of decrease in agricultural area in the region on GDP and region economy was evaluated and compared with released water contribution in lake level rise for a five year simulation period.

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

    Science.gov (United States)

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

    2013-01-01

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

  13. Landowner and permit-holder perceptions of wildlife damage around the Idaho National Engineering and Environmental Laboratory. A survey of INEEL neighbors about elk, mule deer, pronghorn antelope, and depredation

    Energy Technology Data Exchange (ETDEWEB)

    Roush, D.E. Jr. [Environmental Science and Research Foundation, Inc., Idaho Falls, ID (United States); Beaver, D.E. [Univ. of Idaho, Moscow, ID (United States). Coll. of Forestry, Wildlife, and Range Sciences

    1998-06-01

    Property-owners (N = 220) around the Idaho National Engineering and Environmental Laboratory (INEEL) in southeastern Idaho were surveyed about depredation, control methods and economic issues related to use of the area by elk (Cervus elaphus), mule deer (Odocoileus hemionus), and pronghorn antelope (Antilocapra americana). Depredation was defined as damage to privately-owned crops, forage, and fences and irrigation equipment by these animals. The focus on the three ungulate species was prompted by concerns that elk, which had recolonized the INEEL since 1984, were responsible for an inordinate amount of unprecedented damage to agricultural operations. As the INEEL is a US Department of Energy (DOE) reserve with little public hunting access, there have been calls for removal of elk from this land. This study`s objective was to quantify the wildlife damage occurring on agricultural operations adjacent to the INEEL and to characterize the damage attributed to each big game species. Responses from 70.2% of the target population indicate an evenness of opinion, by which the authors mean that various opinions were represented equitably, toward these animals and wildlife damage Total estimated wildlife damage in 1996 was between $140,000 and $180,000 It was attributed foremost to elk, although pronghorn antelope were viewed nearly as damaging. Respondents placed high values in big game animals and wished to see them continue to inhabit these lands. For managing depredation, adjusting hunting seasons was preferred.

  14. Changes in lake level and trophy at Lake Vrana, a large karstic lake on the Island of Cres (Croatia, with respect to palaeoclimate and anthropogenic impacts during the last approx. 16,000 years

    Directory of Open Access Journals (Sweden)

    Ante BARIĆ

    2000-08-01

    Full Text Available A multi-proxy approach study (cladocerans, diatoms, geochemistry, plant macrofossils, pollen, was performed on a sediment core from Lake Vrana (Vransko Jezero, a large and deep karstic lake on the northern Adriatic island of Cres, Croatia. Considerable lake-level changes occurred during the last approx. 16,000 years. The stratigraphic evidence suggests that periods of enhanced precipitation and the post-LGM rise in sea level were the main driving forces. The lake records indicate early human impacts. Sediment echo-sounding indicated that >25 m of lake sediments lies within the site, from which 5 m have been cored. Shallow lake stages occurred from 14.4 14C ky BP to early Holocene. Prior to Alleröd, interglacial sediments were redeposited, reflecting the influences of rising sea-level (forming a local groundwater barrier, a temporary increase in precipitation, and lake-level changes. There appears to be a hiatus in the sequence, for no sediments assignable to the Alleröd chronozone could be found. A discordance in the echo profile at the appropriate horizon in the sequence supports this interpretation. Groundwater level increased again at 10.6 ky BP (during Younger Dryas chronozone, a swamp vegetation formed, which gave way to a shallow lake. During the Preboreal chronozone, this freshwater lake persisted with fluctuating levels. The establishment and subsequent persistence of the present deep water lake at about 8.5 ky BP, correspond with findings of a pluvial period at the Dalmatian coast, which lasted from 8.4 to 6 ky BP. First human catchment disturbances were related to settlements of Neolithic or Bronze Age. The increase in summer drought, coupled with forest clearance during Illyrian times, are assumed to be responsible for the change towards present evergreen oak vegetation in the lake catchment. The intensification in land-use during Roman and post-Roman settlements caused a slight increase in the lake trophic level.

  15. Modeling the GLOF Hazard Process Chain at Imja Lake in the Nepal Himalaya

    Science.gov (United States)

    Lala, J.; McKinney, D. C.; Rounce, D.

    2017-12-01

    The Hindu Kush-Himalaya region contains more glacial ice than any other non-polar region on earth. Many glacial lakes in Nepal are held in place by natural moraine dams, which are inherently unstable. Avalanches or landslides entering glacial lakes can cause tsunami-like waves that can overtop the moraines and trigger glacial lake outburst floods (GLOF). Mass loss at the Imja glacier is the highest in the Mount Everest region, and contributes to the expansion of Imja Tsho, a lake with several villages downstream. A GLOF from the lake might destroy both property and human life, making an understanding of flood triggering processes beneficial for both the downstream villages and other GLOF-prone areas globally. The process chain for an avalanche-induced GLOF was modeled numerically. The volume and velocity of debris from avalanches entering various future lake extents were calculated using RAMMS. Resulting waves and downstream flooding were simulated using BASEMENT to evaluate erosion at the terminal moraine. Wave characteristics in BASEMENT were validated with empirical equations to ensure the proper transfer of momentum from the avalanche to the lake. Moraine erosion was determined for two geomorphologic scenarios: a site-specific scenario using field samples, and a worst-case scenario based on past literature. Both cases resulted in no flooding outside the river channel at downstream villages. Worst-case scenario geomorphology resulted in increased channelization of the lake outlet and some moraine erosion but no catastrophic collapse. Site-specific data yielded similar results but with even less erosion and downstream discharge. While the models confirmed that Imja Tsho is unlikely to produce a catastrophic GLOF in the near future, they also highlight the importance of continued monitoring of the lake. Furthermore, the ease and flexibility of these methods allows for their adoption by a wide range of stakeholders for modeling other high-risk lakes.

  16. Polonium-210 accumulates in a lake receiving coal mine discharges-anthropogenic or natural?

    Science.gov (United States)

    Nelson, A W; Eitrheim, E S; Knight, A W; May, D; Wichman, M D; Forbes, T Z; Schultz, M K

    2017-02-01

    Coal is an integral part of global energy production; however, coal mining is associated with numerous environmental health impacts. It is well documented that coal-mine waste can contaminate the environment with naturally-occurring radionuclides from the uranium-238 ( 238 U) decay series. However, the behavior of the final radionuclide in the 238 U-series, i.e., polonium-210 ( 210 Po) arising from coal-mine waste-water discharge is largely unexplored. Here, results of a year-long (2014-2015) field study, in which the concentrations of 210 Po in sediments and surface water of a lake that receives coal-mine waste-water discharge in West Virginia are presented. Initial measurements identified levels of 210 Po in the lake sediments that were in excess of that which could be attributed to ambient U-series parent radionuclides; and were indicative of discharge site contamination of the lake ecosystem. However, control sediment obtained from a similar lake system in Iowa (an area with no coal mining or unconventional drilling) suggests that the levels of 210 Po in the lake are a natural phenomenon; and are likely unrelated to waste-water treatment discharges. Elevated levels of 210 Po have been reported in lake bottom sediments previously, yet very little information is available on the radioecological implications of 210 Po accumulation in lake bottom sediments. The findings of this study suggest that (Monthly Energy Review, 2016) the natural accumulation and retention of 210 Po in lake sediments may be a greater than previously considered (Chadwick et al., 2013) careful selection of control sites is important to prevent the inappropriate attribution of elevated levels of NORM in lake bottom ecosystems to industrial sources; and (Van Hook, 1979) further investigation of the source-terms and potential impacts on elevated 210 Po in lake-sediment ecosystems is warranted. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Radioactive material in the West Lake Landfill: Summary report

    International Nuclear Information System (INIS)

    1988-04-01

    The West Lake Landfill is located near the city of St. Louis in Bridgeton, St. Louis County, Missouri. The site has been used since 1962 for disposing of municipal refuse, industrial solid and liquid wastes, and construction demolition debris. This report summarizes the circumstances of the radioactive material found in the West Lake Landfill. Primary emphasis is on the radiological environmental aspects as they relate to potential disposition of the material. 8 refs., 2 figs., 1 tab

  18. Hexabromocyclododecane (HBCDD) Flame Retardant in Top Predator Fish across Canada and its 36-Year Temporal Trends for Lake Ontario.

    Science.gov (United States)

    Su, Guanyong; McGoldrick, Daryl; Clark, Mandi G; Evans, Marlene; Gledhill, Melissa; Garron, Christine; Armellin, Alain; Backus, Sean; Letcher, Robert J

    2018-05-08

    Hexabromocyclododecane (HBCDD) is a high concern environmental pollutant due to its persistent, bioaccumulative and toxic properties. The spatial distribution of HBCDD was investigated in top predator fish (Lake Trout, Walleye or Brook Trout) collected in 2013 (n=165) from nineteen sampling sites and in 2015 (n=145) from twenty sites across Canada. HBCDD was measurable in at least one sample at each sampling site regardless of sampling year with the exception of Walleye from the south basin of Lake Winnipeg (2013). Sampling sites in or near the Laurentian Great Lakes had greater HBCDD concentrations compared to locations to the west or east. The greatest mean HBCDD concentration was 72.6 ng/g lw in fish from Lake Huron-Goderich (2015). Regardless of the sampling sites, α-HBCDD was the dominant congener followed by γ-HBCDD, whereas β-HBCDD was barely detectable. In fish from the same waterbody there were comparable α/γ isomer concentration ratios. The greatest ratio was 20.8 in fish from Lake Ontario, whereas the lowest ratio was 6.3 for fish from Lac Memphrémagog (Québec) likely related to more recent emissions of technical HBCDD mixture. Temporal trends of HBCDD in Lake Trout from Lake Ontario showed a significant decreasing trend for γ-HBCDD with a half-life estimate of 10 years over a 36-year period (1979-2015), and for -HBCDD with a half-life of 11 years over the years of 2008 to 2015. The proportion of α-HBCDD to ΣHBCDD increased significantly during 1979 to 2015. The present study provided novel information on the isomer-specific HBCDDs in Canada freshwater fish.

  19. Cormorant predation on PIT-tagged lake fish

    DEFF Research Database (Denmark)

    Skov, Christian; Jepsen, Niels; Baktoft, Henrik

    2014-01-01

    The present study use data from recovered PIT (Passive Integrated Transponder) tags to explore species-and size-specific annual predation rates by cormorants on three common lacustrine fishes (size range 120-367 mm) in a European lake; roach (Rutilus rutilus), common bream (Abramis brama) and perch...... (Perca fluviatilis). In addition, we quantify the level of age/size truncation that cormorant predation could introduce in a population of perch, an important fish for recreational angling as well as for trophic interactions and ecosystem function in European lakes. Based on three years of PIT tagging...... of fish in Lake Viborg and subsequent recoveries of PIT tags from nearby cormorant roosting and breeding sites, we show that cormorants are major predators of roach, bream and perch within the size groups we investigated and for all species larger individuals had higher predation rates. Perch appear...

  20. Cyanobacterial bloom in the world largest freshwater lake Baikal

    Science.gov (United States)

    Namsaraev, Zorigto; Melnikova, Anna; Ivanov, Vasiliy; Komova, Anastasia; Teslyuk, Anton

    2018-02-01

    Lake Baikal is a UNESCO World Heritage Site and holds 20% of the world’s freshwater reserves. On July 26, 2016, a cyanobacterial bloom of a green colour a few kilometers in size with a bad odor was discovered by local people in the Barguzinsky Bay on the eastern shore of Lake Baikal. Our study showed very high concentration of chlorophyll a (41.7 g/m3) in the sample of bloom. We found that the bloom was dominated by a nitrogen-fixing heterocystous cyanobacteria of the genus Dolichospermum. The mass accumulation of cyanobacteria in the lake water with an extremely high chlorophyll a concentration can be explained by a combination of several factors: the discharge of biologicaly-available nutrients, including phosphorus, into the water of Lake Baikal; low wind speed and weak water mixing; buoyant cyanobacterial cells on the lake surface, which drifted towards the eastern coast, where the maximum concentration of chlorophyll a was recorded. In the center of the Barguzinsky Bay and in the open part of Lake Baikal, according to satellite data, the chlorophyll a concentration is several orders of magnitude lower than at the shoreline.

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

    Science.gov (United States)

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

    2017-08-15

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

  2. A Floristic Study of Hamun Lake Basin, South East of Iran

    Directory of Open Access Journals (Sweden)

    Maryam Keshavarzi

    2017-06-01

    Full Text Available Lake Hamun is the largest freshwater resource in Iran with area of about 3820 km2. The present study aims to evaluate the floristic elements of the studied site. Plant samples were gathered from nature, from March to July at the growing season. Life form and chorotype of plants in Lake Hamun basin were investigated. Totally 128 plant species belonging to 80 genera and 30 families were identified. Families as Poaceae, Amaranthaceae and Fabaceae were the most dominant and frequent families. Considering biological types revealed that the most frequent forms were therophytes (61% and hemicryptophytes (17%. Floristic elements of the area were mainly Iranotouranian mixed with Saharo-Arabian and Sindu-Sudanian types, although multi- and bi- regional elements were also frequent. As the lake has recently become an international conserved area, the complete biological and ecological study of the site is a necessity.

  3. Sediment characteristics and wind-induced sediment dynamics in shallow Lake Markermeer, the Netherlands

    NARCIS (Netherlands)

    Kelderman, P.; Ang'weya, R.O.; De Rozari, P.; Vijverberg, T.

    2012-01-01

    In 2007/08, a study was undertaken on the sediment dynamics in shallow Lake Markermeer (the Netherlands). Firstly, sediment characteristics were determined at 49 sites in the lake. Parameters such as median grain size and loss on ignition showed a spatial as well as water depth related pattern,

  4. Surface system Forsmark. Site descriptive modelling SDM-Site Forsmark

    International Nuclear Information System (INIS)

    Lindborg, Tobias

    2008-12-01

    SKB has undertaken site characterization of two different areas, Forsmark and Laxemar-Simpevarp, in order to find a suitable location for a geological repository for spent nuclear fuel. This report focuses on the site descriptive modelling of the surface system at Forsmark. The characterization of the surface system at the site was primarily made by identifying and describing important properties in different parts of the surface system, properties concerning e.g. hydrology and climate, Quaternary deposits and soils, hydrochemistry, vegetation, ecosystem functions, but also current and historical land use. The report presents available input data, methodology for data evaluation and modelling, and resulting models for each of the different disciplines. Results from the modelling of the surface system are also integrated with results from modelling of the deep bedrock system. The Forsmark site is located within the municipality of Oesthammar, about 120 km north of Stockholm. The investigated area is located along the shoreline of Oeregrundsgrepen, a funnel-shaped bay of the Baltic Sea. The area is characterized by small-scale topographic variations and is almost entirely located at altitudes lower than 20 metres above sea level. The Quaternary deposits in the area are dominated by till, characterized by a rich content of calcite which was transported by the glacier ice to the area from the sedimentary bedrock of Gaevlebukten about 100 km north of Forsmark. As a result, the surface waters and shallow groundwater at Forsmark are characterized by high pH values and high concentrations of certain major constituents, especially calcium and bicarbonate. The annual precipitation and runoff are 560 and 150 mm, respectively. The lakes are small and shallow, with mean and maximum depths ranging from approximately 0.1 to 1 m and 0.4 to 2 m. Sea water flows into the most low-lying lakes during events giving rise to very high sea levels. Wetlands are frequent and cover 25 to 35

  5. Emergent Macrophytes Support Zooplankton in a Shallow Tropical Lake: A Basis for Wetland Conservation

    Science.gov (United States)

    Gebrehiwot, Mesfin; Kifle, Demeke; Triest, Ludwig

    2017-12-01

    Understanding the biodiversity value of littoral zones of lakes is a priority for aquatic biodiversity conservation. However, less emphasis has been given to the littoral part of tropical African lakes, with many of the previous researches focusing only on the open water side. The aim of the present study was, therefore, to investigate the impact of the littoral zone of a shallow freshwater tropical lake (Ziway, Ethiopia), dominated by two emergent macrophytes, on zooplankton community structure. We hypothesized that the wetland vegetation serves as a preferred microhabitat for zooplankton communities. A lake with substantial coverage of emergent macrophytes was monitored monthly from January to August, 2016. The monitoring included the measurements of physical, chemical, and biological parameters. Sampling sites were selected to represent areas of the macrophyte vegetation ( Typha latifolia and Phragmites australis) and the open water part of the lake. Sites with macrophyte vegetation were found to be the home of more dense and diverse zooplankton community. However, during the period of high vegetation loss, the density of crustacean zooplankton showed significant reduction within the patches of macrophytes. From biodiversity conservation perspective, it was concluded that the preservation of such small areas of macrophytes covering the littoral zone of lakes could be as important as protecting the whole lake. However, the rapid degradation of wetland vegetation by human activities is a real threat to the lake ecosystem. In the not-too-far future, it could displace and evict riparian vegetation and the biota it supports.

  6. Palaeoecology and geoarchaeology of the Varna Lake, northern Bulgarian Black Sea coast

    Directory of Open Access Journals (Sweden)

    Mariana FILIPOVA-MARINOVA

    2014-11-01

    Full Text Available The coastal lakes are rich sources of biostratigraphic information that is very useful in palaeoecological reconstructions of climate changes and human impact on the natural vegetation. This information is of great importance for the archaeological descriptions of submerged praehistorical settlements found in the northern Bulgarian Black sea area. There are 4 archaeological sites in this area that have been palynologically studied for the last 30 years: the Durankulak Lake, the Shabla-Ezeretz Lake system, the Lake Bolata, as well as the Varna-Beloslav Lake system. Because of the lack of AMS radiocarbon dates for these sites, it was not possible to correlate adequately all palaeoenvironmental results with the available archaeological chronology.Aimed to receive additional information on the Holocene vegetation dynamics and lake level changes, as well as on the anthropogenic impact during the Late Eneolithic and Early Bronze Age, the high-resolution spore-pollen analysis of AMS dated laminated sediments from a new Core 3 – Varna Lake was combined with analyses of dinoflagellate cysts, acritarchs, and other non-pollen palynomorphs.The location of the core is close to several sites of submerged praehistorical settlements and the Varna Late Eneolithic (Chalcolithic Necropolis, which is famous with the oldest hand-made gold treasure in the Worlds, and permits the palaeoenvironmental correlations of obtained results with available archaeological and geochronological data. The core is 995 cm long, but its palynologically investigated length is 870 cm. It contains dark grey clay and laminated sediments (varves. Seven samples of sediments were submitted for radiocarbon dating to the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS Facility of Woods Hole Oceanographic Institution (WHOI. The dates have been calibrated using the program CALIB version 6.1.0 of using the IntCal09 curve. An Age Model for the sedimentation rate was created by the

  7. Karachay lake is the storage of the radioactive wastes under open sky

    International Nuclear Information System (INIS)

    Merkushkin, A.O.

    2001-01-01

    Lake Karachay is situated at 'Mayak' PA site. From October 1951 the lake was used as a storage of technological radioactive waste to stop the waste discharge into the Techa River. At present time the reservoir contains about 120 million Ci of radionuclides. Lake Karachay presents a serious ecological problem being source of the contamination of the air, grounds and underground water. In this work a review of available sources dealing with Karachay's problem is made. Present and past approaches to this problem are shown. (authors)

  8. Preliminary analysis of downhole logging data from ICDP Lake Junin drilling Project, Peru

    Science.gov (United States)

    Pierdominici, Simona; Kück, Jochem; Rodbell, Donald T.; Abbott, Mark B.

    2016-04-01

    The International Continental Drilling Programm (ICDP) has supported a scientific drilling campaign in Peru during the summer season 2015. The Lake Junin Drilling Project mainly aims at obtaining high-resolution paleoclimate records from lacustrine sediments to reconstruct the history of the continental records covering the glacial-interglacial cycles. Lake Junín is located at 4000 m a.s.l. in the tropical Andes of Peru, and is characterized by a thick (> 125 m) sediment package deposited at a high rate (0.2 to 1.0 mm yr-1). Lake Junín is one of the few lakes in the tropical Andes that predates the maximum extent of glaciation and is in a geomorphic position to record the waxing and waning of glaciers in nearby cordillera, hence making the lake a key site for the investigation of the Quaternary climate evolution in the inner-tropics of the Southern Hemisphere. Continous coring was performed at three sites in overall 11 boreholes on the lake with at least two overlapping boreholes per site to avoid core gaps. The depth of the boreholes varied between approx. 30 m and 110 m depending on the drill site. The core bit had a bit size of 122.6 mm and yielded a core diameter of 85 mm. Upon completion of coring operations downhole geophysical logging was performed in five of the 11 boreholes (1A, 1C, 1D, 2A and 3B) by the Operational Support Group of ICDP. The main objective was to record in-situ the physical properties of the lacustrine sediments of Lake Junin. Downhole logs provide a powerful tool to fill in information at intervals with core gaps and as depth reference for depth matching of the discontinous cores. Furthermore it will be used for the lithological reconstruction and interpretation. The OSG downhole logging comprised total and spectrum gamma ray, magnetic susceptibility, borehole geometry, temperature, and sonic P-wave velocity. Unstable and collapsing borehole walls made it neccessary to carry out logging in several sections instead of in one run. The

  9. Fate and transport of petroleum hydrocarbons in the subsurface near Cass Lake, Minnesota

    Science.gov (United States)

    Drennan, Dina M.; Bekins, Barbara A.; Warren, Ean; Cozzarelli, Isabelle M.; Baedecker, Mary Jo; Herkelrath, William N.; Delin, Geoffrey N.; Rosenbauer, Robert J.; Campbell, Pamela L.

    2010-01-01

    The U.S. Geological Survey (USGS) investigated the natural attenuation of subsurface petroleum hydrocarbons leaked over an unknown number of years from an oil pipeline under the Enbridge Energy Limited Partnership South Cass Lake Pumping Station, in Cass Lake, Minnesota. Three weeks of field work conducted between May 2007 and July 2008 delineated a dissolved plume of aromatic hydrocarbons and characterized the biodegradation processes of the petroleum. Field activities included installing monitoring wells, collecting sediment cores, sampling water from wells, and measuring water-table elevations. Geochemical measurements included concentrations of constituents in both spilled and pipeline oil, dissolved alkylbenzenes and redox constituents, sediment bioavailable iron, and aquifer microbial populations. Groundwater in this area flows east-southeast at approximately 26 meters per year. Results from the oil analyses indicate a high degree of biodegradation, characterized by nearly complete absence of n-alkanes. Cass Lake oil samples were more degraded than two oil samples collected in 2008 from the similarly contaminated USGS Bemidji, Minnesota, research site 40 kilometers away. Based on 19 ratios developed for comparing oil sources, the conclusion is that the oils at the two sites appear to be from the same hydrocarbon source. In the Cass Lake groundwater plume, benzene concentrations decrease by three orders of magnitude within 150 meters (m) downgradient from the oil body floating on the water table (between well MW-10 and USGS-4 well nest). The depths of the highest benzene concentrations increase with distance downgradient from the oil, a condition typical of plumes in shallow, unconfined aquifers. Background groundwater, which is nearly saturated with oxygen, becomes almost entirely anaerobic in the plume. As at the Bemidji site, the most important biodegradation processes are anaerobic and dominated by iron reduction. The similarity between the Cass Lake and

  10. Technical procedures for water resources, Deaf Smith County site, Texas: Volume 2: Environmental Field Program: Final draft

    International Nuclear Information System (INIS)

    1987-08-01

    This volume contains the following Technical Procedures pursuant to the Water Resources Site Study Plan operation of a Playa Lake conductivity monitoring station and processing of data from a Playa Lake conductivity monitoring station. This procedure defines steps and methods for the installation, operation, and maintenance of the Playa Lake conductivity monitoring stations. Conductivity measurements will be taken at six playa lakes in the site study area to record changes in total dissolved solids as a function of stage. Playa lake conductivity and stage (volume) measurements will be used, in conjunction with other water quality data collected at the Playa Lake and precipitation stations, to determine the mass of dissolved solids entering and leaving the playas. This baseline information on the pollutant mass balance of the playas will be used to assess potential changes in playa lake water quality and the magnitude of those changes due to site development. The pollutant mass balances will also be used on determining the source of pollutants. 2 refs., 5 figs

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

    Science.gov (United States)

    Wiche, Gregg J.; Vecchia, Aldo V.

    1996-01-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2006-01-01

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

  14. Sediment baseline study of levels and sources of polycyclic aromatic hydrocarbons and heavy metals in Lake Nicaragua

    DEFF Research Database (Denmark)

    Scheibye, Katrine; Weisser, Johan Juhl; Borggaard, Ole K.

    2014-01-01

    Selected metals and polycyclic aromatic hydrocarbons (PAHs) were analyzed in sediment samples from 24 sites in Lake Nicaragua sampled May 2010 to provide a baseline of pollution levels. Cu exceeded the Consensus-Based Sediment Quality Guideline (CBSQG) Threshold Effect Concentrations (TECs) at 21...... showed that the CBSQG TECs were exceeded by naphthalene at five sites. The sum concentrations of the 16 US EPA priority PAHs (∑PAH16) ranged from 0.01mgkg(-1)dw to 0.64mgkg(-1)dw. The highest ∑PAH16 concentration was found upstream in River Mayales and the PAH composition revealed a heavy PAH fraction (e....... This study concluded that areas of Lake Nicaragua represent an important pollution baseline for future studies in this lake and other tropical lakes....

  15. Zooplankton communities in a large prealpine lake, Lake Constance: comparison between the Upper and the Lower Lake

    Directory of Open Access Journals (Sweden)

    Gerhard MAIER

    2005-08-01

    Full Text Available The zooplankton communities of two basins of a large lake, Lake Constance, were compared during the years 2002 and 2003. The two basins differ in morphology, physical and chemical conditions. The Upper Lake basin has a surface area of 470 km2, a mean depth of 100 and a maximum depth of 250 m; the Lower Lake basin has a surface area of 62 km2, a mean depth of only 13 and a maximum depth of 40 m. Nutrient, chlorophyll-a concentrations and mean temperatures are somewhat higher in the Lower than in the Upper Lake. Total abundance of rotifers (number per m2 lake surface was higher and rotifer development started earlier in the year in the Lower than in the Upper Lake. Total abundance of crustaceans was higher in the Upper Lake in the year 2002; in the year 2003 no difference in abundance could be detected between the lake basins, although in summer crustacean abundance was higher in the Lower than in the Upper Lake. Crustacean communities differed significantly between lake basins while there was no apparent difference in rotifer communities. In the Lower Lake small crustaceans, like Bosmina spp., Ceriodaphnia pulchella and Thermocyclops oithonoides prevailed. Abundance (number per m2 lake surface of predatory cladocerans, large daphnids and large copepods was much lower in the Lower than in the Upper Lake, in particular during the summer months. Ordination with nonmetric multidimensional scaling (NMS separated communities of both lakes along gradients that correlated with temperature and chlorophyll a concentration. Clutches of copepods were larger in the Lower than in the Upper Lake. No difference could be detected in clutch size of large daphnids between lake basins. Our results show that zooplankton communities in different basins of Lake Constance can be very different. They further suggest that the lack of large crustaceans in particular the lack of large predatory cladocerans in the Lower Lake can have negative effects on growth and

  16. Lake trout rehabilitation in Lake Erie: a case history

    Science.gov (United States)

    Cornelius, Floyd C.; Muth, Kenneth M.; Kenyon, Roger

    1995-01-01

    Native lake trout (Salvelinus namaycush) once thrived in the deep waters of eastern Lake Erie. The impact of nearly 70 years of unregulated exploitation and over 100 years of progressively severe cultural eutrophication resulted in the elimination of lake trout stocks by 1950. Early attempts to restore lake trout by stocking were unsuccessful in establishing a self-sustaining population. In the early 1980s, New York's Department of Environmental Conservation, Pennsylvania's Fish and Boat Commission, and the U.S. Fish and Wildlife Service entered into a cooperative program to rehabilitate lake trout in the eastern basin of Lake Erie. After 11 years of stocking selected strains of lake trout in U.S. waters, followed by effective sea lamprey control, lake trout appear to be successfully recolonizing their native habitat. Adult stocks have built up significantly and are expanding their range in the lake. Preliminary investigations suggest that lake trout reproductive habitat is still adequate for natural reproduction, but natural recruitment has not been documented. Future assessments will be directed toward evaluation of spawning success and tracking age-class cohorts as they move through the fishery.

  17. Microbiology of Lonar Lake and other soda lakes

    Science.gov (United States)

    Paul Antony, Chakkiath; Kumaresan, Deepak; Hunger, Sindy; Drake, Harold L; Murrell, J Colin; Shouche, Yogesh S

    2013-01-01

    Soda lakes are saline and alkaline ecosystems that are believed to have existed throughout the geological record of Earth. They are widely distributed across the globe, but are highly abundant in terrestrial biomes such as deserts and steppes and in geologically interesting regions such as the East African Rift valley. The unusual geochemistry of these lakes supports the growth of an impressive array of microorganisms that are of ecological and economic importance. Haloalkaliphilic Bacteria and Archaea belonging to all major trophic groups have been described from many soda lakes, including lakes with exceptionally high levels of heavy metals. Lonar Lake is a soda lake that is centered at an unusual meteorite impact structure in the Deccan basalts in India and its key physicochemical and microbiological characteristics are highlighted in this article. The occurrence of diverse functional groups of microbes, such as methanogens, methanotrophs, phototrophs, denitrifiers, sulfur oxidizers, sulfate reducers and syntrophs in soda lakes, suggests that these habitats harbor complex microbial food webs that (a) interconnect various biological cycles via redox coupling and (b) impact on the production and consumption of greenhouse gases. Soda lake microorganisms harbor several biotechnologically relevant enzymes and biomolecules (for example, cellulases, amylases, ectoine) and there is the need to augment bioprospecting efforts in soda lake environments with new integrated approaches. Importantly, some saline and alkaline lake ecosystems around the world need to be protected from anthropogenic pressures that threaten their long-term existence. PMID:23178675

  18. Applicability of API ZYM to capture seasonal and spatial variabilities in lake and river sediments.

    Science.gov (United States)

    Patel, Drashti; Gismondi, Renee; Alsaffar, Ali; Tiquia-Arashiro, Sonia M

    2018-05-02

    Waters draining into a lake carry with them much of the suspended sediment that is transported by rivers and streams from the local drainage basin. The organic matter processing in the sediments is executed by heterotrophic microbial communities, whose activities may vary spatially and temporally. Thus, to capture and evaluate some of these variabilities in the sediments, we sampled six sites: three from the St. Clair River and three from Lake St. Clair in spring, summer, fall, and winter of 2016. At all sites and dates, we investigated the spatial and temporal variations in 19 extracellular enzyme activities using API ZYM. Our results indicated that a broad range of enzymes were found to be active in the sediments. Phosphatases, lipases, and esterases were synthesized most intensively by the sediment microbial communities. No consistent difference was found between the lake and sediment samples. Differences were more obvious between sites and seasons. Sites with the highest metabolic (enzyme) diversity reflected the capacity of the sediment microbial communities to breakdown a broader range of substrates and may be linked to differences in river and lake water quality. The seasonal variability of the enzymes activities was governed by the variations of environmental factors caused by anthropogenic and terrestrial inputs, and provides information for a better understanding of the dynamics of sediment organic matter of the river and lake ecosystems. The experimental results suggest that API ZYM is a simple and rapid enzyme assay procedure to evaluate natural processes in ecosystems and their changes.

  19. Results of the independent radiological verification survey at 4400 Piehl Road, Ottawa Lake, Michigan (BTO002)

    Energy Technology Data Exchange (ETDEWEB)

    Murray, M.E.; Brown, K.S.

    1996-04-01

    At the request of the US Department of Energy (DOE), a team from Oak Ridge National Laboratory (ORNL) conducted an independent radiological verification survey at Ottawa Lake, Michigan. The survey was performed in November and December of 1994. The purpose of the survey was to verify that the site was remediated to levels below the DOE guidelines for FUSRAP sites. Results of the independent radiological verification survey at Ottawa Lake, Michigan confirm that the residual uranium contamination at the site is below DOE FUSRAP guidelines for unrestricted use.

  20. Evaluating lake stratification and temporal trends by using near-continuous water-quality data from automated profiling systems for water years 2005-09, Lake Mead, Arizona and Nevada

    Science.gov (United States)

    Veley, Ronald J.; Moran, Michael J.

    2012-01-01

    The U.S. Geological Survey, in cooperation with the National Park Service and Southern Nevada Water Authority, collected near-continuous depth-dependent water-quality data at Lake Mead, Arizona and Nevada, as part of a multi-agency monitoring network maintained to provide resource managers with basic data and to gain a better understanding of the hydrodynamics of the lake. Water-quality data-collection stations on Lake Mead were located in shallow water (less than 20 meters) at Las Vegas Bay (Site 3) and Overton Arm, and in deep water (greater than 20 meters) near Sentinel Island and at Virgin and Temple Basins. At each station, near-continual depth-dependent water-quality data were collected from October 2004 through September 2009. The data were collected by using automatic profiling systems equipped with multiparameter water-quality sondes. The sondes had sensors for temperature, specific conductance, dissolved oxygen, pH, turbidity, and depth. Data were collected every 6 hours at 2-meter depth intervals (for shallow-water stations) or 5-meter depth intervals (for deep-water stations) beginning at 1 meter below water surface. Data were analyzed to determine water-quality conditions related to stratification of the lake and temporal trends in water-quality parameters. Three water-quality parameters were the main focus of these analyses: temperature, specific conductance, and dissolved oxygen. Statistical temporal-trend analyses were performed for a single depth at shallow-water stations [Las Vegas Bay (Site 3) and Overton Arm] and for thermally-stratified lake layers at deep-water stations (Sentinel Island and Virgin Basin). The limited period of data collection at the Temple Basin station prevented the application of statistical trend analysis. During the summer months, thermal stratification was not observed at shallow-water stations, nor were major maxima or minima observed for specific-conductance or dissolved-oxygen profiles. A clearly-defined thermocline

  1. Localized enrichment of polycyclic aromatic hydrocarbons in soil, spruce needles, and lake sediments linked to in-situ bitumen extraction near Cold Lake, Alberta

    International Nuclear Information System (INIS)

    Korosi, J.B.; Irvine, G.; Skierszkan, E.K.; Doyle, J.R.; Kimpe, L.E.; Janvier, J.; Blais, J.M.

    2013-01-01

    The extraction of bitumen from the Alberta oil sands using in-situ technologies is expanding at a rapid rate; however, investigations into the environmental impacts of oil sands development have focused on surface mining in the Athabasca region. We measured polycyclic aromatic hydrocarbons (PAH) in soils, spruce needles, and lake sediment cores in the Cold Lake oil sands region to provide a historical and spatial perspective on PAH contamination related to in-situ extraction activities. A pronounced increase in PAH concentrations was recorded in one of two study lakes (Hilda Lake) corresponding to the onset of commercial bitumen production in ∼1985. Distance from extraction rigs was not an important predictor of PAH concentrations in soils, although two samples located near installations were elevated in alkyl PAHs. Evidence of localized PAH contamination in Hilda Lake and two soil samples suggests that continued environmental monitoring is justified to assess PAH contamination as development intensifies. -- Highlights: •In-situ bitumen extraction linked to rise in alkyl PAHs in one of two study lakes. •Alkyl PAHs elevated in two soil samples. •PAH contamination likely related to effluent sources, not atmospheric deposition. -- PAHs in sediments and soils were generally low in areas adjacent to in-situ bitumen extraction rigs in the Cold Lake Alberta oil sands, but evidence of localized contamination at some sites was evident

  2. Predicting the locations of naturally fishless lakes

    Science.gov (United States)

    Schilling, Emily Gaenzle; Loftin, C.S.; Degoosh, K.E.; Huryn, Alexander D.; Webster, K.E.

    2008-01-01

    1. Fish have been introduced into many previously fishless lakes throughout North America over the past 100+ years. It is difficult to determine the historical distribution of fishless lakes, however, because these introductions have not always been well-documented. 2. Due to its glacial history and low human population density, the state of Maine (U.S.A.) may host the greatest number of naturally fishless lakes in the northeastern United States. However, less than one-quarter of Maine's 6000+ lakes have been surveyed for fish presence, and no accurate assessments of either the historical or current abundance and distribution of fishless lakes exist. 3. We developed methods to assess the abundance and distribution of Maine's naturally fishless lakes (0.6-10.1 ha). We hypothesized that the historical distribution of fishless lakes across a landscape is controlled by geomorphic and geographic conditions. 4. We used ArcGIS to identify landscape-scale geomorphic and geographic factors (e.g. connectivity, surrounding slope) correlated with fish absence in two geomorphic regions of Maine - the western and interior mountains and the eastern lowlands and foothills. By using readily available geographic information systems data our method was not limited to field-visited sites. We estimated the likelihood that a particular lake is fishless with a stepwise logistic regression model developed for each region. 5. The absence of fish from western lakes is related to altitude (+), minimum percent slope in the 500 m buffer (+), maximum percent slope in the 500 m buffer (+) and percent cover of herbaceous-emergent wetland in 1000 m buffer (-). The absence of fish from eastern lakes is related to the lack of a stream within 50 m of the lake. 6. The models predict that a total of 4% (131) of study lakes in the two regions were historically fishless, with the eastern region hosting a greater proportion than the western region. 7. We verified the model predictions with two

  3. On the radiocesium behavior in a small humic lake (Lithuania)

    International Nuclear Information System (INIS)

    Tarasiuk, N.; Koviazina, E.; Karpicz, R.; Moisejenkova, A.; Astrauskiene, N.

    2009-01-01

    Peculiarities of radiocesium contamination of a small humic lake, which became meromictic some thirty-five years ago due to the inflow of a large amount of humic water, are presented. The lake consists of two separate water layers, which do not intermix. A lower water layer of the lake below some 3-m depth is stagnant and anaerobic, and radiocesium load of the sediments is mainly caused by nuclear weapons fallout. The radiocesium load of the sediments of the upper monomictic water layer is significantly larger due to additional contamination after the Chernobyl accident. Radiocesium activity concentrations in lake water increase with depth, and even in the surface layer, they are commonly the largest among the neighboring lakes with transparent water. It is shown that bottom areas of the monomictic part of the lake with the elevated radiocesium deepening into sediments are related to the favorite sites of the tench (Tinca tinca) winter torpor. Sediment bioturbation and redistribution due to tench activities distort naturally formed radiocesium vertical profiles and they cannot be used for estimations of sedimentation rates and sediment chronology. The studied lake can be useful as an analogous model in analyzing structural and radiological consequences of humic water inflows to closed lakes. Concerning extreme radiological situations in closed humic lakes related to their specific vertical structure, they may be treated as critical objects in assessing the risk to humans after radionuclide deposition events. (authors)

  4. Estimating future temperature maxima in lakes across the United States using a surrogate modeling approach.

    Directory of Open Access Journals (Sweden)

    Jonathan B Butcher

    Full Text Available A warming climate increases thermal inputs to lakes with potential implications for water quality and aquatic ecosystems. In a previous study, we used a dynamic water column temperature and mixing simulation model to simulate chronic (7-day average maximum temperatures under a range of potential future climate projections at selected sites representative of different U.S. regions. Here, to extend results to lakes where dynamic models have not been developed, we apply a novel machine learning approach that uses Gaussian Process regression to describe the model response surface as a function of simplified lake characteristics (depth, surface area, water clarity and climate forcing (winter and summer air temperatures and potential evapotranspiration. We use this approach to extrapolate predictions from the simulation model to the statistical sample of U.S. lakes in the National Lakes Assessment (NLA database. Results provide a national-scale scoping assessment of the potential thermal risk to lake water quality and ecosystems across the U.S. We suggest a small fraction of lakes will experience less risk of summer thermal stress events due to changes in stratification and mixing dynamics, but most will experience increases. The percentage of lakes in the NLA with simulated 7-day average maximum water temperatures in excess of 30°C is projected to increase from less than 2% to approximately 22% by the end of the 21st century, which could significantly reduce the number of lakes that can support cold water fisheries. Site-specific analysis of the full range of factors that influence thermal profiles in individual lakes is needed to develop appropriate adaptation strategies.

  5. Suspended sediment impact on chlorophyll a, nitrogen and phosphorus relationships in Moon Lake, MS

    Science.gov (United States)

    Moon Lake, MS is a 947 ha. oxbow lake of the Mississippi River Alluvial Plain also known as the Mississippi Delta. Water was sampled from five sites, bi-weekly from 1982 to 1985. Analysis of surface water quality reviled loading of nutrients from nonpoint source pollution associated with agricultu...

  6. Lake and watershed influences on the distribution of elemental contaminants in the Rideau Canal System, a UNESCO world heritage site.

    Science.gov (United States)

    Stuyt, Shannon S M; Chapman, E Emily V; Campbell, Linda M

    2015-08-01

    Watershed-specific variables such as sediment particle size distribution, water depth, sedimentation rate, focusing factors, and catchment area to lake area ratio can affect the distribution of trace element contaminants to lakes. The aim of this study was to investigate sources of metals to three headwater lakes and to quantify effects of watershed-specific variables on spatial and temporal trends of trace elements (As, Cd, Co, Cr, Cu, Hg, K, Ni, Pb, Rb, and Zn) in sediments and mercury (Hg) concentrations in fish. Surface sediment and water samples were used to characterize spatial patterns, while sediment cores were collected to portray temporal trends. Historical trends of Hg in northern pike (Esox lucius) were assessed in relation to paleolimnological trends of sediment Hg concentrations. Similarity in timing of sediment peak trace element concentrations for the lakes suggests large-scale, atmospheric sources. The lake with highest catchment area-to-lake area ratio was consistently associated with highest sediment elemental concentrations and displayed significant correlations between increased sediment Hg concentrations and decreased pike tissue concentrations over time. This suggests that catchment area-to-lake area ratio is an important factor influencing the concentration of atmospherically derived contaminants within lake sediments and their transfer through the food web.

  7. Lake ecosystem response to rapid lateglacial climate changes in lake sediments from northern Poland

    Science.gov (United States)

    Słowiński, Michał; Zawiska, Izabela; Ott, Florian; Noryśkiewicz, Agnieszka M.; Apolinarska, Karina; Lutyńska, Monika; Michczyńska, Danuta J.; Brauer, Achim; Wulf, Sabine; Skubała, Piotr; Błaszkiewicz, Mirosław

    2013-04-01

    During the Late Glacial Period environment changes were triggered by climatic oscillations which in turn controlled processes like, for example, permafrost thawing, vegetation development and ground water circulation. These environmental changes are ideally recorded in lake sediments and thus can be reconstructed applying a multi-poxy approach. Here, we present the results from the Trzechowskie paleolake, located in the northern Polish lowlands (eastern part of the Pomeranian Lakeland). The site is situated on the outwash plain of the Wda River, which was formed during the Pomeranian phase of the Vistulian glaciation ca 16,000 14C yrs BP. The depression of the Trzechowskie lake basin formed after melting of a buried ice block during the Allerød (13903±170 cal yrs BP). We reconstructed environmental changes in the Trzechowskie paleolake and its catchment using biotic proxies (macrofossils, pollen, cladocera, diatoms, oribatidae mite) and geochemical proxies (δ18O, δ13C, loss-on-ignition (LOI), CaCO3 content). In addition, we carried out µ-XRF element core scanning. The chronology has been established by means of biostratigraphyAMS14C dating on plant macro remains, varve counting in laminated intervals and the late Allerød Laacher See Tephra isochrone. Our results showed that biogenic accumulation in the lake started during the Bølling. Development of coniferous forest during the Allerød with dominance of Pinus sylvestris lead to leaching of carbonates in the catchment due to low pH increasing the flux of Ca ions into the lake. In consequence calcite precipitating in the lake increased as evidences by increasing CaCO3 contents. Both biotic and physical proxies clearly reflect the rapid decrease in productivity at the onset of the Younger Dryas. We compare the data from the Trzechowskie paleolake with the Meerfelder Maar and Rehwiese lake records based on tephrochronological synchronization using the Laacher See Tephra. This study is a contribution to the

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

    Science.gov (United States)

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

    2001-09-01

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

  9. UMTRA project water sampling and analysis plan, Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    1994-02-01

    This water sampling and analysis plan (WSAP) provides the basis for ground water sampling at the Ambrosia Lake Uranium Mill Tailings Remedial Action (UMTRA) Project site during fiscal year 1994. It identifies and justifies the sampling locations, analytical parameters, detection limits, and sampling frequency for the monitoring locations and will be updated annually. The Ambrosia Lake site is in McKinley County, New Mexico, about 40 kilometers (km) (25 miles [mi]) north of Grants, New Mexico, and 1.6 km (1 mi) east of New Mexico Highway 509 (Figure 1.1). The town closest to the tailings pile is San Mateo, about 16 km ( 10 mi) southeast (Figure 1.2). The former mill and tailings pile are in Section 28, and two holding ponds are in Section 33, Township 14 North, Range 9 West. The site is shown on the US Geological Survey (USGS) map (USGS, 1980). The site is approximately 2100 meters (m) (7000 feet [ft]) above sea level

  10. Measurements of evaporation from a mine void lake and testing of modelling approaches

    Science.gov (United States)

    McJannet, David; Hawdon, Aaron; Van Niel, Tom; Boadle, Dave; Baker, Brett; Trefry, Mike; Rea, Iain

    2017-12-01

    Pit lakes often form in the void that remains after open cut mining operations cease. As pit lakes fill, hydrological and geochemical processes interact and these need to be understood for appropriate management actions to be implemented. Evaporation is important in the evolution of pit lakes as it acts to concentrate various constituents, controls water level and changes the thermal characteristics of the water body. Despite its importance, evaporation from pit lakes is poorly understood. To address this, we used an automated floating evaporation pan and undertook measurements at a pit lake over a 12 month period. We also developed a new procedure for correcting floating pan evaporation estimates to lake evaporation estimates based on surface temperature differences. Total annual evaporation was 2690 mm and reflected the strong radiation inputs, high temperatures and low humidity experienced in this region. Measurements were used to test the performance of evaporation estimates derived using both pan coefficient and aerodynamic modelling techniques. Daily and monthly evaporation estimates were poorly reproduced using pan coefficient techniques and their use is not recommended for such environments. Aerodynamic modelling was undertaken using a range of input datasets that may be available to those who manage pit lake systems. Excellent model performance was achieved using over-water or local over-land meteorological observations, particularly when the sheltering effects of the pit were considered. Model performance was reduced when off-site data were utilised and differences between local and off-site vapor pressure and wind speed were found to be the major cause.

  11. Preliminary Report on Unique Laminated Holocene Sediments from the Qarun Lake in Egypt

    Directory of Open Access Journals (Sweden)

    Marks Leszek

    2016-06-01

    Full Text Available The Lake Qarun (Faiyum Oasis, northern Egypt is a relic of the much larger Holocene lake. Past lake levels and extensions were reconstructed, based on setting of archaeological sites scattered along northern paleoshores of the ancient lake. However, geoarcheological works did not yield enough data to establish continuous environmental history of the lake. A deep drilling FA-1 on the southeastern shore of the lake, performed in 2014, supplied with a core, 26 m long that is the one of the longest lake sediment cores in northeastern Africa. The basal section of the core consisted of thin-laminated diatom marly deposits, underlain at the Late Pleistocene/Holocene boundary by coarse-grained sands. The sediment lamine were quite well developed, especially in the lower part of the core. Preliminary results indicated annually deposited sediment sequence with seasonality signals provided by microlamine of diatoms, calcite, organic matter and clastic material. Early Holocene varved sediments from the Faiyum Oasis supplied with exceptional paleoenvironmental data for northeastern Africa, which enriched a record from previous logs drilled at the southwestern margin of the Qarun Lake.

  12. Nitrogen Dynamics Variation in Overlying Water of Jinshan Lake, China

    Directory of Open Access Journals (Sweden)

    Xiaohong Zhou

    2015-01-01

    Full Text Available Jinshan Lake is a famous urban landscape lake with approximately 8.8 km2 water area, which is located on the north of Zhenjiang, of Jiangsu Province, China. Eighteen sampled sites were selected and overlying water was sampled from 2013 to 2014 to study the seasonal and spatial variation of nitrogen in overlying water of Jinshan Lake. Results showed that physicochemical characteristics of temperature, pH, and DO showed high seasonal variation, whereas they had no significant spatial differences in the 18 sampling points (P>0.05 in overlying water of Jinshan Lake. Nitrogen concentrations showed strong seasonal variation trends. The ranked order of TN was as follows: spring > summer > autumn > winter; the order of NH4+-N was as follows: spring > autumn > summer > winter, whereas NO3--N concentrations revealed an inverse seasonal pattern, with maxima occurring in winter and minimal values occurring in spring. Nitrogen concentrations had dramatic spatial changes in 18 sampling points of Jinshan Lake. Physicochemical parameter difference, domestic wastes pollution, and rainfall runoff source may have led to seasonal and spatial fluctuation variations of nitrogen in overlying water of Jinshan Lake, China.

  13. Characterization of three acid strip mine lakes in Grundy County, Illinois

    Energy Technology Data Exchange (ETDEWEB)

    Master, W. A.

    1979-09-01

    Three small lakes with acid water and one with circumneutral water at an abandoned strip mine site were characterized to identify factors limiting biological productivity. Dissolved oxygen, specific conductance, and temperature profiles were determined. Water samples were analyzed for 23 parameters, and the lakes were examined for the presence of aquatic vascular plants and benthic inhabitants. The acid lakes ranged from 0.9 ha to 2.7 ha in surface area and from 3.1 m to 6.7 m in maximum depth. The mean pH of the acid lakes ranged from 3.1 to 3.9. Chemicals found at concentrations higher than Illinois surface water standards or federal criteria for the protection of aquatic life included Cd, Cu, Fe, Mn, SO/sub 4/=, and Zn. A number of these chemicals were at sufficiently high concentrations to limit the survival and productivity of most aquatic fauna. The lake with the poorest water quality had the least diversity of aquatic vascular plants and benthic invertebrates, while the circumneutral lake had the greatest diversity of species.

  14. Characterization of water and lake sediments in Laguna de Bay

    International Nuclear Information System (INIS)

    San Diego, Cherry Ann; Francisco, Pattrice Armynne; Navoa, Joshua Antonio; Johnson, Bryan; Dave, Harshil; Cryer, Karl; Panemanglor, Rajeev; Rama, Mariecar; Sucgang, Raymond J.

    2011-01-01

    In this work we studied elemental distributions of trace elements, dissolved oxygen and microbiological allotment (total plate count, Coliform, and E. coli) in sediment and surface water from 3 sites in Laguna de Bay. The measured parameters were associated with the quality of the water and to anthropogenic and geogenic processes taking place in the lake. In all cases sediment samples were collected and analyzed for elemental composition using an X-ray fluorescence technique. Water samples were collected and analyzed for nitrate, chloride, and sulfate ions using selective electrodes. Bicarbonate ions in the lake water were determined by titration. The microbial load (total plate count, total coliform and E,. Coli) were determined using Simplate. Field parameters such as pH and conductivity were likewise measured. Preliminary assumptions suggest that proximity to anthropogenic sources has substantially contributed to the combined loads of major ions pollution in the lake. Laguna de Bay is classified as Class C (DENR Administrative Order No. 34). For all the sites, the conductivity of the water were considerably elevated, which ranged from 929 to 933 uS/cm; Site 1 water exceeded the permissible range for pH for Class C water which is 6.5 to 8.5 for the support and rearing of fish. None of the lake waters exceeded the limits for the ions, chloride (set at 350 mg/L) and nitrate (set at 10 mg/L), for Class C water criteria. All the sites meet the dissolved oxygen, DO, criterion for Class C waters which is set at 5 mg/L. In terms of microbiological load, Site 1 had the least most probable number per ml of water, MPN/ml: total plate count (6720), Coliform (less that detection limit) and E. coli (less than LLD); Site 3 was the most contaminated: total plate count (greater than 70,000), Coliform(48768) and E. Coli (23808). X-ray fluorescence analyses of sediments allowed the determination of elements Na, Mg, Al, P, Si, Cl, K. Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, As, Br, Rb

  15. 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 in January and February 2002 for Lake Victoria and in March and April 2002 for Lake Burigi. Ten genera were recorded from four zones of Lake Victoria while only ...

  16. Lake Morphometry for NHD Lakes in Great Lakes Region 4 HUC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

  17. ('fingerponds\\') in the wetlands of Lake Victoria, Kenya

    African Journals Online (AJOL)

    The potential effect on ecosystem integrity of the use of natural wetlands for seasonal wetland fishponds ('fingerponds\\'), integrated with vegetable production for livelihood demands, was evaluated using experimental sites at Lake Victoria, Kenya. Soluble reactive phosphorous and total phosphorus, ammonium, nitrate and ...

  18. Geophysical Investigation of a Thermokarst Lake Talik in Continuous Permafrost

    Science.gov (United States)

    Creighton, A.; Parsekian, A.; Arp, C. D.; Jones, B. M.; Babcock, E.; Bondurant, A. C.

    2016-12-01

    On the Arctic Coastal Plain (ACP) of northern Alaska, shallow thermokarst lakes cover up to 25% of the landscape. These lakes occupy depressions created by the subsidence of thawed, ice-rich permafrost. Areas of unfrozen sediment, or taliks, can form under lakes that have a mean annual bottom temperature greater than 0°C. The geometry of these taliks, as well as the processes that create them, are important for understanding interactions between surface water, groundwater, and carbon cycling. Non-invasive geophysical methods are a useful means to study talik sediments as borehole studies yield few data points, and the contrast between unfrozen and frozen sediments is an ideal geophysical target. To study talik configuration associated with an actively expanding thermokarst lake, we conducted a geophysical transect across Peatball Lake. This lake has an estimated initiation age of 1400 calendar years BP. Over the past 60 years, lake surface area has increased through thermal and mechanical shoreline erosion. A talik of previously unknown thickness likely exists below Peatball Lake. We conducted a transect of transient electromagnetic soundings across the lake extending into the surrounding terrestrial environment. Since permafrost has relatively high resistivity compared to talik sediments, the interpreted electrical structure of the subsurface likely reflects talik geometry. We also conducted nuclear magnetic resonance soundings at representative locations along the transect. These measurements can provide data on sub-lake sediment properties including water content. Together, these measurements resolve the talik structure across the lake transect and showed evidence of varying talik thicknesses from the lake edge to center. These is no evidence of a talik at the terrestrial control sites. These results can help constrain talik development models and thus provide insight into Arctic and permafrost processes in the face of a changing climate.

  19. Inter-annual variations in water yield to lakes in northeastern Alberta: implications for estimating critical loads of acidity

    Directory of Open Access Journals (Sweden)

    Roderick HAZEWINKEL

    2010-08-01

    Full Text Available Stable isotopes of water were applied to estimate water yield to fifty lakes in northeastern Alberta as part of an acid sensitivity study underway since 2002 in the Athabasca Oil Sands Region (AOSR. Herein, we apply site-specific water yields for each lake to calculate critical loads of acidity using water chemistry data and a steady-state water chemistry model. The main goal of this research was to improve site-specific critical load estimates and to understand the sensitivity to hydrologic variability across a Boreal Plains region under significant oil sands development pressure. Overall, catchment water yields were found to vary significantly over the seven year monitoring period, with distinct variations among lakes and between different regions, overprinted by inter-annual climate-driven shifts. Analysis of critical load estimates based on site-specific water yields suggests that caution must be applied to establish hydrologic conditions and define extremes at specific sites in order to protect more sensitive ecosystems. In general, lakes with low (high water yield tended to be more (less acid sensitive but were typically less (more affected by interannual hydrological variations. While it has been customary to use long-term water yields to define a static critical load for lakes, we find that spatial and temporal variability in water yield may limit effectiveness of this type of assessment in areas of the Boreal Plain characterized by heterogeneous runoff and without a long-term lake-gauging network. Implications for predicting acidification risk are discussed for the AOSR.

  20. Changing climate in the Lake Superior region: a case study of the June 2012 flood and its effects on the western-lake water column

    Science.gov (United States)

    Minor, E. C.; Forsman, B.; Guildford, S. J.

    2013-12-01

    In Lake Superior, the world's largest freshwater lake by area, we are seeing annual surface-water temperature increases outpacing those of the overlying atmosphere. We are also seeing ever earlier onsets of water-column stratification (in data sets from the mid-1980s to the present). In Minnesota, including the Lake Superior watershed, precipitation patterns are also shifting toward fewer and more extreme storm events, such as the June 2012 solstice flood, which impacted the western Lake Superior basin. We are interested in how such climatological changes will affect nutrient and carbon biogeochemistry in Lake Superior. The lake is currently an oligotrophic system exhibiting light limitation of primary production in winter and spring, with summer primary production generally limited by phosphorus and sometimes co-limited by iron. Analyses in the western arm of Lake Superior showed that the June 2012 flood brought large amounts of sediment and colored dissolved organic matter (CDOM) from the watershed into the lake. There was initially a ~50-fold spike in the total phosphorus concentrations (and a 5 fold spike in soluble reactive phosphorus) in flood-impacted waters. This disappeared rapidly, in large part due to sediment settling and did not lead to an increase in chlorophyll concentrations at monitored sampling sites. Instead, lake phytoplankton appeared light limited by a surface lens of warm water enriched in CDOM that persisted for over a month after the flood event itself. Our observations highlight the need for continuing research on these complex in-lake processes in order to make accurate predictions about longer term impacts of these large episodic inputs in CDOM, sediment, and nutrient loading.

  1. Potentially dangerous glacial lakes in Kyrgyzstan - Research overview of 2004-2015

    Science.gov (United States)

    Jansky, Bohumir; Yerokhin, Sergey; Sobr, Miroslav; Engel, Zbynek; Cerny, Michal; Falatkova, Kristyna; Kocum, Jan; Benes, Vojtech

    2016-04-01

    Global warming causes intensive melting and retreat of glaciers in most of high mountains all over the world. This process is also evident in the mountain regions of central Tien Shan. Glacier melt water affects changes in hydrological regime of water streams and causes overfilling of high mountain lake basins. The dams of many lakes are very unstable and can burst open. To determine the degree of such risk, it is necessary to analyse the genesis of lakes, to characterize the morphology of the lake basins and to know the particularities of their hydrological regime. According to the latest inventory within territory of Kyrgyzstan, a total of 1328 lakes have been identified as potentially dangerous, 12 lakes are considered as currently dangerous, other 25 feature high potential hazard. Since 1952 more than 70 disastrous cases of lake outburst have been registered. The hazardous alpine lakes are studied in Kyrgyzstan systematically since 1966. Since 2004, Czech-Kyrgyz research team has been operating in Kyrgyzstan in the field of dangerous glacial lakes. Projects were focused primarily on high-mountain glacial lakes risk assessment, propositions of risk mitigation measures, establishment of permanent research station near one of the studied glacier complexes, preparation of risk analysis for selected endangered valleys, evaluation of climatic and hydrological data and glacier development within observed regions. The most significant portion of data and information has been gathered during field work, complemented by satellite image analysis and surveillance flights over the monitored sites.

  2. Data Validation Package December 2015 Groundwater Sampling at the Ambrosia Lake, New Mexico, Disposal Site March 2016

    Energy Technology Data Exchange (ETDEWEB)

    Tsosie, Bernadette [USDOE Office of Legacy Management, Washington, DC (United States); Johnson, Dick [Navarro Research and Engineering, Inc., Oak Ridge, TN (United States)

    2016-03-01

    The Long-Term Surveillance Plan for the Ambrosia Lake, New Mexico, Disposal Site does not require groundwater monitoring because groundwater in the uppermost aquifer is of limited use, and supplemental standards have been applied to the aquifer. However, at the request of the New Mexico Environment Department, the U.S. Department of Energy conducts annual monitoring at three locations: monitoring wells 0409, 0675, and 0678. Sampling and analyses were conducted as specified in the Sampling and Analysis Plan for US. Department of Energy Office of Legacy Management Sites (LMS/PRO/S04351, continually updated). Monitoring Well 0409 was not sampled during this event because it was dry. Water levels were measured at each sampled well. One duplicate sample was collected from location 0675. Groundwater samples from the two sampled wells were analyzed for the constituents listed in Table 1. Time-concentration graphs for selected analytes are included in this report. At well 0675, the duplicate results for total dissolved solids and for most metals (magnesium, molybdenum, potassium, selenium, sodium, and uranium) were outside acceptance criteria, which may indicate non-homogeneous conditions at this location. November 2014 results for molybdenum and uranium at well 0675 also were outside acceptance criteria. The well condition will be evaluated prior to the next sampling event.

  3. Bacterial Abundance and Activity across Sites within Two Northern Wisconsin Sphagnum Bogs.

    Science.gov (United States)

    Fisher; Graham; Graham

    1998-11-01

    Abstract Bacterial abundance, temperature, pH, and dissolved organic carbon (DOC) concentration were compared across surface sites within and between two northern Wisconsin Sphagnum peatlands over the summer seasons in 1995 and 1996. Sites of interest were the Sphagnum mat surface, the water-filled moat (lagg) at the bog margin, and the bog lake littoral zone. Significant differences in both bacterial populations and water chemistry were observed between sites. pH was highest in the lake and lowest in the mat at both bogs; the opposite was true for DOC. Large populations of bacteria were present in surface interstitial water from the mat; abundance in this site was consistently higher than in the moat or lake. Bacterial abundance also increased across sites of increasing DOC concentration and declining pH. Bacterial activities (rates of [3H]leucine incorporation) and growth in dilution cultures (with grazers removed) were also assessed in lake, moat, and mat sites. Results using these measures generally supported the trends observed in abundance, although high rates of [3H]leucine incorporation were recorded in the moat at one of the bogs. Our results indicate that bacterial populations in Sphagnum peatlands are not adversely affected by acidity, and that DOC may be more important than pH in determining bacterial abundance in these environments.

  4. Land, lake, and fish: Investigation of fish remains from Gesher Benot Ya'aqov (paleo-Lake Hula).

    Science.gov (United States)

    Zohar, Irit; Biton, Rebecca

    2011-04-01

    The question of whether or not pre-modern hominins were responsible for the accumulation of fish remains is discussed through analyses of remains recovered from two lacustrine facies (I-4 and I-5) from Area A of the Acheulian site of Gesher Benot Ya'aqov (GBY) in the Jordan Rift Valley, Israel. The fish remains provide the first glimpse into the naturally accumulated fish assemblage from the fluctuating shores of a lake that had been continually exploited by early hominins some 780,000 years ago. Preliminary analysis of the remains show that thirteen of the seventeen species native to Lake Hula were identified at GBY. These represent three of the five freshwater fish families native to the lake: Cyprinidae (carps), Cichlidae (tilapini, St. Peter's fish), and Clariidae (catfish). From a taphonomical perspective, a significant difference is found between the two lithofacies (Layers I-4 and I-5) in terms of species composition, richness, diversity, and skeleton completeness. It appears that the fish remains recovered from Layer I-4 (clay) are better preserved than those from Layer I-5 (coquina). In both lithofacies, Cyprinidae are highly abundant while Cichlidae and Clariidae are rare and under-represented, especially when compared to the Lake Hula fishery report from the 1950s. All of these identified species may have contributed significantly to the diet of GBY hominins. Copyright © 2010 Elsevier Ltd. All rights reserved.

  5. Statistical analysis of lake levels and field study of groundwater and surface-water exchanges in the northeast Twin Cities Metropolitan Area, Minnesota, 2002 through 2015: Chapter A of Water levels and groundwater and surface-water exchanges in lakes of the northeast Twin Cities Metropolitan Area, Minnesota, 2002 through 2015

    Science.gov (United States)

    Jones, Perry M.; Trost, Jared J.; Diekoff, Aliesha L.; Rosenberry, Donald O.; White, Eric A.; Erickson, Melinda L.; Morel, Daniel L.; Heck, Jessica M.

    2016-10-19

    ages of recharge may have resulted from the wide range in the open-interval lengths and depths for the wells.Results from stable isotope analyses of water samples, lake-sediment coring, continuous seismic-reflection profiling, and water-level and flow monitoring indicated that there is groundwater inflow from nearshore sites and lake-water outflow from deep-water sites in White Bear Lake. Continuous seismic-reflection profiling indicated that deep sections of White Bear, Pleasant, Turtle, and Big Marine Lakes have few trapped gases and little organic material, which indicates where groundwater and lake-water exchanges are more likely. Water-level differences between White Bear Lake and piezometer and seepage measurements in deep waters of the lake indicate that groundwater and lake-water exchange is happening in deep waters, predominantly downgradient from the lake and into the lake sediment. Seepage fluxes measured in the nearshore sites of White Bear Lake generally were higher than seepage fluxes measured in the deep-water sites, which indicates that groundwater-inflow rates at most of the nearshore sites are higher than lake-water outflow from the deep-water sites.

  6. Critical examination of information related to the ecological impact of mining sites on Ritord drainage basin and Saint-Pardoux lake. Preliminary study

    International Nuclear Information System (INIS)

    Garnier-Laplace, J.; Beaugelin-Seiller, K.

    2006-01-01

    This expertise report addresses the potential impact of liquid releases of any kind due to mining sites managed by AREVA on aquatic ecosystems (rivers, dams, lakes, and so on). The analysis comprises a detailed analysis of a report published by SENES Consultants on the potential effects on the roach and other fish species present in the St-Pardoux lake in relationship with their exposure to radionuclides, and a proposition of additional studies for the assessment of the ecological risk associated with releases of radioactive substances and of metals in relationship with the past and present exploitation and management of mining sites. A second part proposes an overview of European methods of assessment of the ecological risk and impact. The traditional method comprises an identification of hazards, an analysis of effects through a critical examination of relationship between dose and associated effects for each substance with a determination of predicted no-effect concentrations (PNEC), an analysis of exposure ways through a calculation or measurement of concentrations to which a part of an ecosystem may be exposed (PEC, predicted environmental concentration), and the risk characterization. Evolutions and approaches are discussed. The third part discusses the study performed by SENES Consultants. The method is presented as well as main general criteria for radiological and chemical aspects. Critics are formulated on the approach to the radiological and chemical aspects, and on the conclusions of this study. The fourth part proposes a brief discussion of the AREVA decennial environmental review and proposes additional studies regarding the screening performed on ecosystems

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

    Science.gov (United States)

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

    2013-01-01

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

  8. The behaviour of residual contaminants at a former station site, Antarctica

    International Nuclear Information System (INIS)

    Webster, Jenny; Webster, Kerry; Nelson, Peter; Waterhouse, Emma

    2003-01-01

    Minor contamination by metals, phosphorus, and fuel products were found at a former research station site in Antarctica. - In 1994, New Zealand's only mainland Antarctic base, Vanda Station, was removed from the shores of Lake Vanda, in the McMurdo Dry Valleys region of southern Victoria Land, Antarctica. Residual chemical contamination of the station site has been identified, in the form of discrete fuel spills, locally elevated Pb, Zn, Ag and Cd concentrations in soil and elevated Cu, Ni, Co and phosphate concentrations in suprapermafrost fluids in a gully formerly used for domestic washing water disposal. Pathways for contaminant transfer to Lake Vanda, potential environmental impacts and specific remediation/monitoring options are considered. While some contaminants (particularly Zn) could be selectively leached from flooded soil, during a period of rising lake level, the small area of contaminated soils exposed and low level of contamination suggests that this would not adversely affect either shallow lake water quality or the growth of cyanobacteria. Phosphate-enhanced growth of the latter may, however, be a visible consequence of the minor contamination occurring at this site

  9. Algal and water-quality data for Rapid Creek and Canyon Lake near Rapid City, South Dakota, 2007

    Science.gov (United States)

    Hoogestraat, Galen K.; Putnam, Larry D.; Graham, Jennifer L.

    2008-01-01

    This report summarizes the results of algae and water-quality sampling on Rapid Creek and Canyon Lake during May and September 2007. The overall purpose of the study was to determine the algal community composition of Rapid Creek and Canyon Lake in relation to organisms that are known producers of unwanted tastes and odors in drinking-water supplies. Algal assemblage structure (phytoplankton and periphyton) was examined at 16 sites on Rapid Creek and Canyon Lake during May and September 2007, and actinomycetes bacteria were sampled at the Rapid City water treatment plant intake in May 2007, to determine if taste-and-odor producing organisms were present. During the May 2007 sampling, 3 Rapid Creek sites and 4 Canyon Lake sites were quantitatively sampled for phytoplankton in the water column, 7 Rapid Creek sites were quantitatively sampled for attached periphyton, and 4 lake and retention pond sites were qualitatively sampled for periphyton. Five Rapid Creek sites were sampled for geosmin and 2-methylisoborneol, two common taste-and-odor causing compounds known to affect water supplies. During the September 2007 sampling, 4 Rapid Creek sites were quantitatively sampled for attached periphyton, and 3 Canyon Lake sites were qualitatively sampled for periphyton. Water temperature, dissolved oxygen, pH, and specific conductance were measured during each sampling event. Methods of collection and sample analysis are presented for the various types of biological and chemical constituent samples. Diatoms comprised 91-100 percent of the total algal biovolume in periphyton samples collected during May and September. Cyanobacteria (also called blue-green algae) were detected in 7 of the 11 quantitative periphyton samples and ranged from 0.01 to 2.0 percent of the total biovolume. Cyanobacteria were present in 3 of the 7 phytoplankton samples collected in May, but the relative biovolumes were small (0.01-0.2 percent). Six of seven qualitative samples collected from Canyon Lake

  10. Evaluating the importance of abiotic and biotic drivers on Bythotrephes biomass in Lakes Superior and Michigan

    Science.gov (United States)

    Keeler, Kevin M.; Bunnell, David B.; Diana, James S.; Adams, Jean V.; Mychek-Londer, Justin G.; Warner, David M.; Yule, Daniel; Vinson, Mark

    2015-01-01

    The ability of planktivorous fishes to exert top-down control on Bythotrephes potentially has far-reaching impacts on aquatic food-webs, given previously described effects of Bythotrephes on zooplankton communities. We estimated consumption of Bythotrephes by planktivorous and benthivorous fishes, using bioenergetics and daily ration models at nearshore (18 m), intermediate (46 m), and offshore (110 m) depths along one western Lake Superior transect (April, and September-November) and two northern Lake Michigan transects (April, July, September). In Lake Superior, consumption (primarily by cisco Coregonus artedi) exceeded Bythotrephes production at all offshore sites in September-November (up to 396% of production consumed) and at the intermediate site in November (842%) with no evidence of consumption nearshore. By comparing Bythotrephes biomass following months of excessive consumption, we conservatively concluded that top-down control was evident only at the offshore site during September-October. In Lake Michigan, consumption by fishes (primarily alewife Alosa pseudoharengus) exceeded production at nearshore sites (up to 178%), but not in deeper sites (additive models, temperature, and not fish consumption, not zooplankton prey density, best explained variability in Bythotrephes biomass. The non-linear pattern revealed Bythotrephes to increase with temperature up to 16 °C, and then decline between 16 and 23 °C. We discuss how temperature likely has direct negative impacts on Bythotrephes when temperatures near 23 °C, but speculate that predation also contributes to declining biomass when temperatures exceed 16 °C.

  11. Summary of the engineering assessment of inactive uranium mill tailings: Phillips/United Nuclear site, Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    1981-10-01

    Ford, Bacon and Davis Utah, Inc., has reevaluated the Phillips/United Nuclear site in order to revise the December 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Ambrosia Lake, New Mexico. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 2.6 million dry tons of tailings at the Phillips/United Nuclear site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The four alternative actions presented in this engineering assessment range from millsite decontamination with the addition of 3 m of stabilization cover material, to removal of the tailings to remote disposal sites and decontamination of the tailings site. Cost estimates for the four options range from about $21,500,000 for stabilization in-place, to about $45,200,000 for disposal at a distance of about 15 mi. Three principal alternatives for the reprocessing of the Phillips/United Nuclear tailings were examined: heap leaching; treatment at an existing mill; reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be about $87/lb of U 3 O 8 by either heap leach or conventional plant process. The spot market price for uranium was $25/lb early in 1981. Reprocessing the Phillips/United Nuclear tailings for uranium recovery does not appear to be economically attractive under present or foreseeable market conditions

  12. The first US National Coastal Condition Assessment survey in the Great Lakes: Development of the GIS frame and exploration of spatial variation in nearshore water quality results

    Science.gov (United States)

    A comprehensive approach to assess conditions in the Great Lakes nearshore zone has been lacking for decades. We had the opportunity to conduct a pilot survey in Lake Erie (45 sites) in summer 2009 and to develop a full survey across the 5 lakes (~400 sites) as part of the US N...

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

    Science.gov (United States)

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

    2006-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  15. Landsat-based trend analysis of lake dynamics across northern permafrost regions

    Science.gov (United States)

    Nitze, Ingmar; Grosse, Guido; Jones, Benjamin M.; Arp, Christopher D.; Ulrich, Mathias; Federov, Alexander; Veremeeva, Alexandra

    2017-01-01

    Lakes are a ubiquitous landscape feature in northern permafrost regions. They have a strong impact on carbon, energy and water fluxes and can be quite responsive to climate change. The monitoring of lake change in northern high latitudes, at a sufficiently accurate spatial and temporal resolution, is crucial for understanding the underlying processes driving lake change. To date, lake change studies in permafrost regions were based on a variety of different sources, image acquisition periods and single snapshots, and localized analysis, which hinders the comparison of different regions. Here we present, a methodology based on machine-learning based classification of robust trends of multi-spectral indices of Landsat data (TM,ETM+, OLI) and object-based lake detection, to analyze and compare the individual, local and regional lake dynamics of four different study sites (Alaska North Slope, Western Alaska, Central Yakutia, Kolyma Lowland) in the northern permafrost zone from 1999 to 2014. Regional patterns of lake area change on the Alaska North Slope (-0.69%), Western Alaska (-2.82%), and Kolyma Lowland (-0.51%) largely include increases due to thermokarst lake expansion, but more dominant lake area losses due to catastrophic lake drainage events. In contrast, Central Yakutia showed a remarkable increase in lake area of 48.48%, likely resulting from warmer and wetter climate conditions over the latter half of the study period. Within all study regions, variability in lake dynamics was associated with differences in permafrost characteristics, landscape position (i.e. upland vs. lowland), and surface geology. With the global availability of Landsat data and a consistent methodology for processing the input data derived from robust trends of multi-spectral indices, we demonstrate a transferability, scalability and consistency of lake change analysis within the northern permafrost region.

  16. Holocene hydrologic variation at Lake Titicaca, Bolivia/Peru, and its relationship to North Atlantic climate variation

    Science.gov (United States)

    Baker, P. A.; Fritz, S. C.; Garland, J.; Ekdahl, E.

    2005-10-01

    A growing number of sites in the Northern Hemisphere show centennial- to millennial-scale climate variation that has been correlated with change in solar variability or with change in North Atlantic circulation. However, it is unclear how (or whether) these oscillations in the climate system are manifest in the Southern Hemisphere because of a lack of sites with suitably high sampling resolution. In this paper, we reconstruct the lake-level history of Lake Titicaca, using the carbon isotopic content of sedimentary organic matter, to evaluate centennial- to millennial-scale precipitation variation and its phasing relative to sites in the Northern Hemisphere. The pattern and timing of lake-level change in Lake Titicaca is similar to the ice-rafted debris record of Holocene Bond events, demonstrating a possible coupling between precipitation variation on the Altiplano and North Atlantic sea-surface temperatures (SSTs). The cold periods of the Holocene Bond events correspond with periods of increased precipitation on the Altiplano. Holocene precipitation variability on the Altiplano is anti-phased with respect to precipitation in the Northern Hemisphere monsoon region. More generally, the tropical Andes underwent large changes in precipitation on centennial-to-millennial timescales during the Holocene.

  17. An Investigation of the Impacts of Climate and Environmental Change on Alpine Lakes in the Uinta Mountains, Utah

    Science.gov (United States)

    Moser, K. A.; Hundey, E. J.; Porinchu, D. F.

    2007-12-01

    Aquatic systems in alpine and sub-alpine areas of the western United States are potentially impacted by atmospheric pollution and climate change. Because these mountainous regions are an important water resource for the western United States, it is critical to monitor and protect these systems. The Uinta Mountains are an east- west trending mountain range located on the border between Utah, Wyoming and Colorado and downwind of the Wasatch Front, Utah, which is characterized by a rapidly expanding population, as well as mining and industry. This alpine area provides water to many areas in Utah, and contributes approximately nine percent of the water supply to the Upper Colorado River. Our research is focused on determining the impacts of climate change and pollution on alpine lakes in the Uinta Mountains. The results presented here are based on limnological measurements made at 64 Uinta Mountain lakes spanning a longitude gradient of one degree and an elevation gradient of 3000 feet. At each lake maximum depth, conductivity, salinity, pH, Secchi depth, temperature, alkalinity, and concentrations of major anions, cations and trace metals were measured. Principal Components Analysis (PCA) was performed to determine relationships between these variables and to examine the variability of the values of these variables. Our results indicate that steep climate gradients related to elevation and longitude result in clear differences in limnological properties of the study sites, with high elevation lakes characterized by greater amounts of nitrate and nitrite compared to low elevation sites. As well, diatoms in these lakes indicate that many high elevation sites are mesotrophic to eutrophic, which is unexpected for such remote aquatic ecosystems. We hypothesize that elevated nitrate and nitrite levels at high elevation sites are related to atmospherically derived nitrogen, but are being exacerbated relative to lower elevation sites by greater snow cover and reduced plant

  18. Relative Influence of Prior Life Stages and Habitat Variables on Dragonfly (Odonata: Gomphidae Densities among Lake Sites

    Directory of Open Access Journals (Sweden)

    Alysa Remsburg

    2011-04-01

    Full Text Available Many aquatic species have discrete life stages, making it important to understand relative influences of the different habitats occupied within those populations. Although population demographics in one stage can carry over to spatially separated life stages, most studies of habitat associations have been restricted to a single life stage. Among Gomphidae dragonflies (Odonata: Anisoptera, recruitment via adult oviposition establishes initial population sizes of the aquatic larvae. However, spatial variability in larval survivorship could obscure the relationship between adult and larval densities. This study uses surveys conducted during 2005 and 2006 of Gomphidae larval, emergence, and adult stages from 22 lake sites in northern Wisconsin, USA, to investigate (1 whether the Gomphidae density of each life stage correlated spatially with that of the preceding life stage and (2 what habitat factors help explain variation in densities at each life stage. Results indicated that adult densities from the previous season helped predict densities of early-instar larvae. This finding suggests that oviposition site selection controlled the local larval distribution more than larval survivorship or movement. Late-instar larval densities helped predict densities of emerging Gomphidae later the same season, suggesting that variation in survivorship of final-instar larvae among sites is small relative to the variation in larval recruitment. This study demonstrates that locations with higher densities of odonates in the water also have higher densities of odonates on land. In addition to the densities of Gomphidae in previous life stages, water clarity helped predict larval densities, and riparian wetland vegetation helped predict emergent dragonfly densities.

  19. Multiscale Terrain Analysis of Multibeam Bathymetry Data for Lake Trout Spawning Habitat Mapping in the Drummond Island Refuge, northern Lake Huron

    Science.gov (United States)

    Wattrus, N. J.; Binder, T.

    2012-12-01

    Until the 1950s, lake trout supported a valuable commercial fishery in the Great Lakes. The introduction of sea lamprey into the Great Lakes and overfishing resulted in the loss of most populations. Despite consistent stocking efforts since the 1960s, restoration of these populations has been slow. The reasons are numerous, but may be related to differences in the spawning behavior between hatchery and wild trout. A four-year study initiated in 2010, utilizes acoustic telemetry to characterize and compare the spawning behaviors of hatchery and wild lake trout in the Drummond Island Refuge in northern Lake Huron. In this project, the movement of tagged fish are monitored by an array of over 125 lake floor hydrophones during the fall spawning period. Fish behavior is overlaid over detailed bathymetric and substrate data and compared with environmental variables (e.g. water temperature, wind speed and direction, and wave height and direction) to develop a conceptual behavioral model. Sites suspected of being spawning sites based upon telemetry data are verified through the use of divers and trapping eggs and fry. Prior to this study, the factors that influenced how the spawning fish utilize the lake floor shoals have been poorly understood. Among the factors thought to impact spawning success were: bathymetry and substrate composition. Diver and telemetry data suggest that the fish(both hatchery raised and wild) are particularly attracted to rocky substrates and that fragment size is important. High resolution multibeam bathymetric surveys conducted in 2010 and 2011 have been used to characterize the shape and composition of the lake floor in the study area. Classification of the substrate is a labor intensive process requiring divers, drop cameras and sediment sampling. To improve this, the traditional approach has been to use supervised and unsupervised classification techniques that are based upon measured acoustic backscatter from an echosounder or sidescan sonar

  20. Great Lakes clams find refuge from zebra mussels in restored, lake-connected marsh (Ohio)

    Science.gov (United States)

    Nichols, S. Jerrine; Wilcox, Douglas A.

    2004-01-01

    Since the early 1990s, more than 95 percent of the freshwater clams once found in Lake Erie have died due to the exotic zebara mussel (Dreissena polymorpha). Zebra mussels attach themselves to native clams in large numbers, impeding the ability of the clams to eat and burrow. However, in 1996, we discovered a population of native clams in Metzger Marsh in western Lake Erie (about 50 miles [80 km] east of Toledo) that were thriving despite the longtime presence of zebra mussel in surrounding waters. At that time, Metzger Marsh was undergoing extensive restoration, including construction of a dike to replace the eroded barrier beach and of a water-control structure to maintain hydrologic connections with the lake (Wilcox and Whillans 1999). The restoration plan called for a drawdown of water levels to promote plant growth from the seedbank -- a process that would also destroy most of the clam population. State and federal resource managers recommended removing as many clams as possible to a site that was isolated from zebra mussels, and then returning them to the marsh after it was restored. We removed about 7,000 native clams in 1996 and moved them back to Metzger Marsh in 1999.

  1. Bioaccumulation and biomagnification of mercury in African lakes: The importance of trophic status

    Energy Technology Data Exchange (ETDEWEB)

    Poste, Amanda E., E-mail: amanda.poste@niva.no [Norwegian Institute for Water Research, Gaustadalléen 21, 0349 Oslo (Norway); Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1 (Canada); Muir, Derek C.G. [Aquatic Contaminants Research Division, Environment Canada, 867 Lakeshore Drive, Burlington, ON L7R 4A6 (Canada); Guildford, Stephanie J.; Hecky, Robert E. [Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1 (Canada); Large Lakes Observatory, University of Minnesota Duluth, 2205 East Fifth Street, Duluth, MN 55812 (United States)

    2015-02-15

    Despite the global prevalence of both mercury (Hg) contamination and anthropogenic eutrophication, relatively little is known about the behavior of Hg in eutrophic and hypereutrophic systems or the effects of lake trophic status on Hg uptake and trophodynamics. In the current study we explore Hg trophodynamics at 8 tropical East African study sites ranging from mesotrophic to hypereutrophic, in order to assess the influence of lake trophic status on Hg uptake and biomagnification. Comprehensive water, plankton and fish samples were collected for analysis of total mercury (THg) and stable carbon and nitrogen isotopic ratios. We found evidence that uptake of THg into phytoplankton tended to be lower in higher productivity systems. THg concentrations in fish were generally low, and THg trophic magnification factors (TMFs; representing the average increase in contaminant concentrations from one trophic level to the next) ranged from 1.9 to 5.6. Furthermore TMFs were significantly lower in hypereutrophic lakes than in meso- and eutrophic lakes, and were negatively related to chlorophyll a concentrations both across our study lakes, and across African lakes for which literature data were available. These observations suggest that THg concentrations were strongly influenced by trophic status, with year-round high phytoplankton and fish growth rates reducing the potential for high THg in fish in these productive tropical lakes. - Highlights: • We characterized Hg in water and biota from 8 East African study sites. • Hg concentrations in fish were low and should not pose a risk to human consumers. • Hg uptake and biomagnification rates were negatively related to trophic status. • Growth dilution in phytoplankton and consumer trophic levels led to low fish Hg.

  2. Bioaccumulation and biomagnification of mercury in African lakes: The importance of trophic status

    International Nuclear Information System (INIS)

    Poste, Amanda E.; Muir, Derek C.G.; Guildford, Stephanie J.; Hecky, Robert E.

    2015-01-01

    Despite the global prevalence of both mercury (Hg) contamination and anthropogenic eutrophication, relatively little is known about the behavior of Hg in eutrophic and hypereutrophic systems or the effects of lake trophic status on Hg uptake and trophodynamics. In the current study we explore Hg trophodynamics at 8 tropical East African study sites ranging from mesotrophic to hypereutrophic, in order to assess the influence of lake trophic status on Hg uptake and biomagnification. Comprehensive water, plankton and fish samples were collected for analysis of total mercury (THg) and stable carbon and nitrogen isotopic ratios. We found evidence that uptake of THg into phytoplankton tended to be lower in higher productivity systems. THg concentrations in fish were generally low, and THg trophic magnification factors (TMFs; representing the average increase in contaminant concentrations from one trophic level to the next) ranged from 1.9 to 5.6. Furthermore TMFs were significantly lower in hypereutrophic lakes than in meso- and eutrophic lakes, and were negatively related to chlorophyll a concentrations both across our study lakes, and across African lakes for which literature data were available. These observations suggest that THg concentrations were strongly influenced by trophic status, with year-round high phytoplankton and fish growth rates reducing the potential for high THg in fish in these productive tropical lakes. - Highlights: • We characterized Hg in water and biota from 8 East African study sites. • Hg concentrations in fish were low and should not pose a risk to human consumers. • Hg uptake and biomagnification rates were negatively related to trophic status. • Growth dilution in phytoplankton and consumer trophic levels led to low fish Hg

  3. Concentrations, Trends, and Air-Water Exchange of PAHs and PBDEs Derived from Passive Samplers in Lake Superior in 2011.

    Science.gov (United States)

    Ruge, Zoe; Muir, Derek; Helm, Paul; Lohmann, Rainer

    2015-12-01

    Polycyclic aromatic hydrocarbons (PAHs) and polybrominated diphenylethers (PBDEs) are both currently released into the environment from anthropogenic activity. Both are hence primarily associated with populated or industrial areas, although wildfires can be an important source of PAHs, as well. Polyethylene passive samplers (PEs) were simultaneously deployed in surface water and near surface atmosphere to determine spatial trends and air-water gaseous exchange of 21 PAHs and 11 PBDEs at 19 sites across Lake Superior in 2011. Surface water and atmospheric PAH concentrations were greatest at urban sites (up to 65 ng L(-1) and 140 ng m(-3), respectively, averaged from June to October). Near populated regions, PAHs displayed net air-to-water deposition, but were near equilibrium off-shore. Retene, probably depositing following major wildfires in the region, dominated dissolved PAH concentrations at most Lake Superior sites. Atmospheric and dissolved PBDEs were greatest near urban and populated sites (up to 6.8 pg L(-1) and 15 pg m(-3), respectively, averaged from June to October), dominated by BDE-47. At most coastal sites, there was net gaseous deposition of BDE-47, with less brominated congeners contributing to Sault Ste. Marie and eastern open lake fluxes. Conversely, the central open lake and Eagle Harbor sites generally displayed volatilization of PBDEs into the atmosphere, mainly BDE-47.

  4. Paleo-radioecology of Lake Sevan, Armenia

    International Nuclear Information System (INIS)

    Nalbandyan, A.; Ananyan, V.; Burnett, W.; Cable, J.

    2005-01-01

    This joint Armenian-American research was performed on Lake Sevan in period 2002-2004 in the frame of a NFSAT/CRDF project P aleoecology and paleo-radioecology of Lake Sevan, Armenia . The basic goal was conducting a detailed paleolimnological and radio-ecological study of Lake Sevan by sediment dating with 210Pb and 137Cs and geochemical analyses of sediment cores to reveal both natural and man-made changes that occurred in the lake over the last 120 years. The research was being performed by the CENS Laboratory of Radioecology and the Departments of Oceanography at the FSU and LSU (USA). The study object - Lake Sevan, the second highest freshwater lake in the world - is situated at a height 1916 m a.s.l. Such geographical position makes the lake an ideal site for obtaining and preserving valuable historical radio-ecological records of natural variations, man-induced changes, global fallout after nuclear weapon testing and the 1986 Chernobyl accident. Coring was accomplished during two cruises in 2002 and 2003. Sediment cores up to ∼ 1 m in length were collected from 8 locations in the Sevan. An important part of this research was sediment dating via analysis of 210Pb and 137Cs by direct-spectrometry (FSU, LSU). 226Ra, 137Cs, 40K, 234Th concentrations were determined at CENS through a low-background -spectrometry. To explore the possibility of ecological changes we analyzed several ecological indicators in the lake sediments: biogenic Si, total and available P (AVP), carbonates, and organic carbon. As found out, 210Pb is mainly concentrated in upper sediment layers (0-30cm), deeper its contents significantly decrease and approach equilibrium with 226Ra; 137Cs accumulates in the upper sediment layer (0-50cm) and shows two maxima representing fallout from the 1986 Chernobyl accident and from global bomb-testing that reached the peak in 1963. The ages of each level in the cores were calculated through CRS (constant rate of supply) model. There are some substantial

  5. Silver contamination on abiotic and biotic compartments of Nahuel Huapi National Park lakes, Patagonia, Argentina

    International Nuclear Information System (INIS)

    Ribeiro Guevara, Sergio; Arribere, Maria; Bubach, Debora; Vigliano, Pablo; Rizzo, Andrea; Alonso, Marcelo; Sanchez, Ricardo

    2005-01-01

    The Ag contents of abiotic and biotic compartments of different lakes of Nahuel Huapi National Park, Patagonia, Argentina were analyzed. The water bodies studied were lakes Nahuel Huapi, Moreno, Escondido, Espejo Chico and Traful, the latter chosen as a reference lake. The Ag concentration profiles of short sediment cores, dated by 210 Pb and 137 Cs techniques, were analyzed, as well as suspended load collected from three sites of lake Nahuel Huapi. The biota studied were the native mussel Diplodon chilensis (digestive gland and total soft tissues pooled samples) and five species of fish, two native and three introduced (liver and muscle pooled samples). Ag contents were determined by Instrumental Neutron Activation Analysis (INAA). The upper layers of the sediment cores sampled in lake Nahuel Huapi were enriched in Ag contents compared to deep layers in accumulation periods corresponding to the second half of the 20th century, but this enrichment was neither observed in the reference lake Traful, nor in lakes Espejo Chico and Escondido. Ag was enriched over background level (0.1 μg g -1 ) also in suspended load collected in lake Nahuel Huapi. Ag fluxes to sediments were computed for suspended load and enriched sediment core layers. Highest Ag fluxes, from 350 to 470 μg m -2 year -1 , were measured in Nahuel Huapi near the site where the liquid effluents of the Bariloche city sewage treatment plant are released to the lake. The spatial distribution of the other Ag fluxes suggests that this is the main source of Ag to lake Nahuel Huapi and lateral transport occurs within the water body. Ag concentrations on biota samples were consistent with these conclusions. Mussels collected in lake Nahuel Huapi showed higher Ag concentrations than in the other lakes, especially when compared to lake Traful. Ag contents in mussels were strongly associated with sediment intake, but enriched probably due to sediment grain size sorting during the intake processes. Evidence of food

  6. History of metal contamination in Lake Illawarra, NSW, Australia.

    Science.gov (United States)

    Schneider, Larissa; Maher, William; Potts, Jaimie; Batley, Graeme; Taylor, Anne; Krikowa, Frank; Chariton, Anthony; Zawadzki, Atun; Heijnis, Henk; Gruber, Bernd

    2015-01-01

    Lake Illawarra has a long history of sediment contamination, particularly by metals, as a result of past and current industrial operations and land uses within the catchment. In this study, we examined the history of metal contamination in sediments using metal analysis and (210)Pb and (137)Cs dating. The distributions of copper, zinc, arsenic, selenium, cadmium and lead concentrations within sediment cores were in agreement with historical events in the lake, and indicated that metal contamination had been occurring since the start of industrial activities in Port Kembla in the late 1800 s. Most metal contamination, however, has occurred since the 1960s. Sedimentation rates were found to be 0.2 cm year(-1) in Griffins Bay and 0.3 cm year(-1) in the centre of the lake. Inputs from creeks bringing metals from Port Kembla in the northeast of the lake and a copper slag emplacement from a former copper refinery on the Windang Peninsula were the main sources of metal inputs to Lake Illawarra. The metals of highest concern were zinc and copper, which exceeded the Australian and New Zealand sediment quality guideline values at some sites. Results showed that while historical contamination persists, current management practices have resulted in reduced metal concentrations in surface sediments in the depositional zones in the centre of the lake. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Hazards of volcanic lakes: analysis of Lakes Quilotoa and Cuicocha, Ecuador

    Directory of Open Access Journals (Sweden)

    G. Gunkel

    2008-01-01

    Full Text Available Volcanic lakes within calderas should be viewed as high-risk systems, and an intensive lake monitoring must be carried out to evaluate the hazard of potential limnic or phreatic-magmatic eruptions. In Ecuador, two caldera lakesLakes Quilotoa and Cuicocha, located in the high Andean region >3000 a.s.l. – have been the focus of these investigations. Both volcanoes are geologically young or historically active, and have formed large and deep calderas with lakes of 2 to 3 km in diameter, and 248 and 148 m in depth, respectively. In both lakes, visible gas emissions of CO2 occur, and an accumulation of CO2 in the deep water body must be taken into account.

    Investigations were carried out to evaluate the hazards of these volcanic lakes, and in Lake Cuicocha intensive monitoring was carried out for the evaluation of possible renewed volcanic activities. At Lake Quilotoa, a limnic eruption and diffuse CO2 degassing at the lake surface are to be expected, while at Lake Cuicocha, an increased risk of a phreatic-magmatic eruption exists.

  8. Echinococcus granulosus sensu stricto (s.s.) from the critically endangered antelope Addax nasomaculatus in Tunisia.

    Science.gov (United States)

    Boufana, Belgees; Saïd, Yousra; Dhibi, Mokhtar; Craig, Philip S; Lahmar, Samia

    2015-12-01

    Echinococcus granulosus sensu lato (s.l.) is a zoonotic disease highly endemic in Tunisia. Canids including stray and semi-stray dogs, jackals and foxes are known as definitive hosts and a wide range of ungulates have been shown to harbour the metacestode hydatid stage and may serve as intermediate hosts. Fertile hydatid cysts of Echinococcus equinus and E. granulosus sensu stricto (s.s.) were recently molecularly identified for the first time from Tunisian donkeys. E. granulosus (s.s.) was also identified from wild boars in Tunisia. Here we report the confirmation of hydatid cysts caused by E. granulosus (s.s.) in the critically endangered antelope, Addax nasomaculatus in Tunisia. DNA-based molecular analysis revealed that A.nasomaculatus was infected with E. granulosus (s.s.) which had a 100% identity with the main globally distributed E. granulosus (s.s.) (EgTu01) haplotype. Cysts of Taenia hydatigena (n=33) were also observed on the liver and in the body cavity. Due to their endangered status and their relatively small numbers, it is unlikely that hydatid infection of A. nasomaculatus will form a major contribution to the epidemiology and transmission of E. granulosus in Tunisia, but infection may result in pathology, morbidity and early mortality, and may still play a role in the perpetuation of the parasite in wildlife cycles. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Water quality in Danube Delta Lakes: An assessment using benthic macroinvertebrates community

    Directory of Open Access Journals (Sweden)

    IBRAM Orhan

    2016-12-01

    Full Text Available An assessment of the ecological status of selected lakes in the Danube Delta Biosphere Reserve was done based on temporal and spatial variation of macroinvertebrate communities during 2012 and 2013. Macroinvertebrate communities and measures of these communities were evaluated and a baseline characterization of assemblages was determined for the analyzed sites. Each year, three sampling campaigns, one for each ice-free season were organized for data collection. Macroinvertebrate samples have been collected in every lake from three different stations with the use of an Ekmann dredge. The highest taxa richness are recorded in Fortuna and Isac lakes in 2013. Total abundance followed a pattern similar to taxa number with Fortuna and Isac lakes having the highest yearly values (maximum number of individuals – 225 - per sample has been recorded in September 2013, in Isac Lake.Using saprobic index as an indicator of ecological status Isac lake was classifies as moderate and other three lakes, Merhei, Furtuna and Rosu as good ecological status. Lack of correlation between diversity indices and the saprobic values suggests that other assessment methods could be more effective and provide better information than saprobic index does at least for Danube Delta.

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

    International Nuclear Information System (INIS)

    Adams, W.C.

    2010-01-01

    The Rio Algom Mining (RAM) Limited Liability Corporation Ambrosia Lake site began processing uranium-bearing ore in 1958. Operating under U. S. Nuclear Regulatory Commission (NRC) Source Material License SUA-1473, the site processed approximately 33 million tons of ore through 1985 and continued to be an active uranium production facility through December 2002. Reclamation of the tailings began in 1989 and included the excavation and disposal of unlined evaporation pond residues, contaminated soil cleanup, construction of surface water erosion protection features and the demolition of the mill buildings (NRC 2006). Construction of the Section 4 evaporation ponds commenced in 1976 and was completed in 1979. The ponds were used to evaporate liquid wastes generated from RAM's processing mill. The ponds remained in active service until April 2004; reclamation activities included the pond sediments being relocated to the main tailings disposal area (KOMEX 2006). Other reclamation activities included the excavation and disposal of unlined evaporation pond residues, contaminated soil clean-up, completion of the majority of the required reclamations for Impoundments 1 and 2, construction of a rock apron on Impoundment 2 and demolition of the conventional milling structures and most support facilities. Additional activities at the site included the construction of erosion protection features adjacent to the tailings disposal facility. On January 19, 2005, the RAM submitted a Soil Decommissioning Plan for its Ambrosia Lake uranium mill tailings facility, specifically the evaporation ponds, to the NRC. The NRC requested, in several comment letters, that RAM provide additional information and a revised plan (NRC 2006). RAM issued a revised decommissioning plan (DP) that addresses the methods and procedures implemented to ensure soil remediation meets the requirements of the Uranium Mill Tailings Radiation Control Act (UMTRCA) and NRC regulations contained within the Code of

  11. Environmental Degradation in a Eutrophic Shallow Lake is not Simply Due to Abundance of Non-native Cyprinus carpio

    Science.gov (United States)

    Ramírez-Herrejón, Juan P.; Mercado-Silva, Norman; Balart, Eduardo F.; Moncayo-Estrada, Rodrigo; Mar-Silva, Valentín; Caraveo-Patiño, Javier

    2015-09-01

    Non-native species are often major drivers of the deterioration of natural ecosystems. The common carp Cyprinus carpio are known to cause major changes in lentic systems, but may not be solely responsible for large scale changes in these ecosystems. We used data from extensive collection efforts to gain insight into the importance of carp as drivers of ecosystem change in Lake Patzcuaro, Mexico. We compared the structure (fish density, biomass, diversity, and evenness) of fish assemblages from six Lake Patzcuaro sites with different habitat characteristics. Intersite comparisons were carried out for both wet and dry seasons. We explored the relationships between non-carp species and carp; and studied multivariate interactions between fish abundance and habitat characteristics. From a biomass perspective, carp was dominant in only four of six sites. In terms of density, carp was not a dominant species in all sites. Further, carp density and biomass were not negatively related to native species density and biomass, even when carp density and biomass were positively correlated to water turbidity levels. Carp dominated fish assemblages in the shallowest sites with the highest water turbidity, plant detritus at the bottom, and floating macrophytes covering the lake surface. These results suggest that the effect of carp on fish assemblages may be highly dependent on habitat characteristics in Lake Patzcuaro. Watershed degradation, pollution, water level loss, and other sources of anthropogenic influence may be more important drivers of Lake Patzcuaro degradation than the abundance of carp.

  12. Environmental Degradation in a Eutrophic Shallow Lake is not Simply Due to Abundance of Non-native Cyprinus carpio.

    Science.gov (United States)

    Ramírez-Herrejón, Juan P; Mercado-Silva, Norman; Balart, Eduardo F; Moncayo-Estrada, Rodrigo; Mar-Silva, Valentín; Caraveo-Patiño, Javier

    2015-09-01

    Non-native species are often major drivers of the deterioration of natural ecosystems. The common carp Cyprinus carpio are known to cause major changes in lentic systems, but may not be solely responsible for large scale changes in these ecosystems. We used data from extensive collection efforts to gain insight into the importance of carp as drivers of ecosystem change in Lake Patzcuaro, Mexico. We compared the structure (fish density, biomass, diversity, and evenness) of fish assemblages from six Lake Patzcuaro sites with different habitat characteristics. Intersite comparisons were carried out for both wet and dry seasons. We explored the relationships between non-carp species and carp; and studied multivariate interactions between fish abundance and habitat characteristics. From a biomass perspective, carp was dominant in only four of six sites. In terms of density, carp was not a dominant species in all sites. Further, carp density and biomass were not negatively related to native species density and biomass, even when carp density and biomass were positively correlated to water turbidity levels. Carp dominated fish assemblages in the shallowest sites with the highest water turbidity, plant detritus at the bottom, and floating macrophytes covering the lake surface. These results suggest that the effect of carp on fish assemblages may be highly dependent on habitat characteristics in Lake Patzcuaro. Watershed degradation, pollution, water level loss, and other sources of anthropogenic influence may be more important drivers of Lake Patzcuaro degradation than the abundance of carp.

  13. Description of surface hydrology and near-surface hydrogeology at Forsmark. Site descriptive modelling SDM. Site Forsmark

    International Nuclear Information System (INIS)

    Johansson, Per-Olof

    2008-12-01

    This report describes the modelling of the surface hydrology and near-surface hydrogeology that was performed for the final site descriptive model of Forsmark produced in the site investigation stage, SDM-Site Forsmark. The comprehensive investigation and monitoring programme forms a strong basis for the developed conceptual and descriptive model of the hydrological and near-surface hydrological system of the site investigation area. However, there are some remaining uncertainties regarding the interaction of deep and near-surface groundwater and surface water of importance for the understanding of the system: The groundwaters in till below Lake Eckarfjaerden, Lake Gaellbotraesket, Lake Fiskarfjaerden and Lake Bolundsfjaerden have high salinities. The hydrological and hydrochemical interpretations indicate that these waters are relict waters of mainly marine origin. From the perspective of the overall water balance, the water below the central parts of the lakes can be considered as stagnant. However, according to the hydrochemical interpretation, these waters also contain weak signatures of deep saline water. Rough chloride budget calculations for the Gaellbotraesket depression also raise the question of a possible upward flow of deep groundwater. No absolute conclusion can be drawn from the existing data analyses regarding the key question of whether there is a small ongoing upward flow of deep saline water. However, Lake Bolundsfjaerden is an exception where the clear downward flow gradient from the till to the bedrock excludes the possibility of an active deep saline source. The available data indicate that there are no discharge areas for flow systems involving deep bedrock groundwater in the northern part of the tectonic lens, where the repository is planned to be located (the so-called 'target area'). However, it can not be excluded that such discharge areas exist. Data indicate that the prevailing downward vertical flow gradients from the QD to the bedrock

  14. Description of surface hydrology and near-surface hydrogeology at Forsmark. Site descriptive modelling SDM. Site Forsmark

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Per-Olof (Artesia Grundvattenkonsult AB, Taeby (Sweden))

    2008-12-15

    This report describes the modelling of the surface hydrology and near-surface hydrogeology that was performed for the final site descriptive model of Forsmark produced in the site investigation stage, SDM-Site Forsmark. The comprehensive investigation and monitoring programme forms a strong basis for the developed conceptual and descriptive model of the hydrological and near-surface hydrological system of the site investigation area. However, there are some remaining uncertainties regarding the interaction of deep and near-surface groundwater and surface water of importance for the understanding of the system: The groundwaters in till below Lake Eckarfjaerden, Lake Gaellbotraesket, Lake Fiskarfjaerden and Lake Bolundsfjaerden have high salinities. The hydrological and hydrochemical interpretations indicate that these waters are relict waters of mainly marine origin. From the perspective of the overall water balance, the water below the central parts of the lakes can be considered as stagnant. However, according to the hydrochemical interpretation, these waters also contain weak signatures of deep saline water. Rough chloride budget calculations for the Gaellbotraesket depression also raise the question of a possible upward flow of deep groundwater. No absolute conclusion can be drawn from the existing data analyses regarding the key question of whether there is a small ongoing upward flow of deep saline water. However, Lake Bolundsfjaerden is an exception where the clear downward flow gradient from the till to the bedrock excludes the possibility of an active deep saline source. The available data indicate that there are no discharge areas for flow systems involving deep bedrock groundwater in the northern part of the tectonic lens, where the repository is planned to be located (the so-called 'target area'). However, it can not be excluded that such discharge areas exist. Data indicate that the prevailing downward vertical flow gradients from the QD to

  15. The endemic gastropod fauna of Lake Titicaca: correlation between molecular evolution and hydrographic history.

    Science.gov (United States)

    Kroll, Oliver; Hershler, Robert; Albrecht, Christian; Terrazas, Edmundo M; Apaza, Roberto; Fuentealba, Carmen; Wolff, Christian; Wilke, Thomas

    2012-07-01

    Lake Titicaca, situated in the Altiplano high plateau, is the only ancient lake in South America. This 2- to 3-My-old (where My is million years) water body has had a complex history that included at least five major hydrological phases during the Pleistocene. It is generally assumed that these physical events helped shape the evolutionary history of the lake's biota. Herein, we study an endemic species assemblage in Lake Titicaca, composed of members of the microgastropod genus Heleobia, to determine whether the lake has functioned as a reservoir of relic species or the site of local diversification, to evaluate congruence of the regional paleohydrology and the evolutionary history of this assemblage, and to assess whether the geographic distributions of endemic lineages are hierarchical. Our phylogenetic analyses indicate that the Titicaca/Altiplano Heleobia fauna (together with few extralimital taxa) forms a species flock. A molecular clock analysis suggests that the most recent common ancestor (MRCAs) of the Altiplano taxa evolved 0.53 (0.28-0.80) My ago and the MRCAs of the Altiplano taxa and their extralimital sister group 0.92 (0.46-1.52) My ago. The endemic species of Lake Titicaca are younger than the lake itself, implying primarily intralacustrine speciation. Moreover, the timing of evolutionary branching events and the ages of two precursors of Lake Titicaca, lakes Cabana and Ballivián, is congruent. Although Lake Titicaca appears to have been the principal site of speciation for the regional Heleobia fauna, the contemporary spatial patterns of endemism have been masked by immigration and/or emigration events of local riverine taxa, which we attribute to the unstable hydrographic history of the Altiplano. Thus, a hierarchical distribution of endemism is not evident, but instead there is a single genetic break between two regional clades. We also discuss our findings in relation to studies of other regional biota and suggest that salinity tolerance was

  16. Spatial difference in genetic variation for fenitrothion tolerance between local populations of Daphnia galeata in Lake Kasumigaura, Japan.

    Science.gov (United States)

    Mano, Hiroyuki; Tanaka, Yoshinari

    2017-12-01

    This study examines the spatial difference in genetic variation for tolerance to a pesticide, fenitrothion, in Daphnia galeata at field sites in Lake Kasumigaura, Japan. We estimated genetic values of isofemale lines established from dormant eggs of D. galeata collected from field sampling sites with the toxicant threshold model applied using acute toxicity. We compared genetic values and variances and broad-sense heritability across different sites in the lake. Results showed that the mean tolerance values to fenitrothion did not differ spatially. The variance in genetic value and heritability of fenitrothion tolerance significantly differed between sampling sites, revealing that long-term ecological risk of fenitrothion may differ between local populations in the lake. These results have implications for aquatic toxicology research, suggesting that differences in genetic variation of tolerance to a chemical among local populations must be considered for understanding the long-term ecological risks of the chemical over a large geographic area.

  17. Paleoenvironments, Evolution, and Geomicrobiology in a Tropical Pacific Lake: The Lake Towuti Drilling Project (TOWUTI)

    Science.gov (United States)

    Vogel, Hendrik; Russell, James M.; Bijaksana, Satria; Crowe, Sean; Fowle, David; Haffner, Douglas; King, John; Marwoto, Ristiyanti; Melles, Martin; von Rintelen, Thomas; Stevenson, Janelle; Watkinson, Ian; Wattrus, Nigel

    2014-05-01

    Lake Towuti (2.5°S, 121°E) is a, 560 km2, 200-m deep tectonic lake at the downstream end of the Malili lake system, a set of five, ancient (1-2 MYr) tectonic lakes in central Sulawesi, Indonesia. Lake Towuti's location in central Indonesia provides a unique opportunity to reconstruct long-term paleoclimate change in a crucially important yet understudied region- the Indo-Pacific warm pool (IPWP), heart of the El Niño-Southern Oscillation. The Malili Lakes have extraordinarily high rates of floral and faunal endemism, and the lakes are surrounded by one of the most diverse tropical forests on Earth. Drilling in Lake Towuti will identify the age and origin of the lake and the environmental and climatic context that shaped the evolution of this unique lacustrine and terrestrial ecosystem. The ultramafic (ophiolitic) rocks and lateritic soils surrounding Lake Towuti provide metal substrates that feed a diverse, exotic microbial community, analogous to the microbial ecosystems that operated in the Archean Oceans. Drill core will provide unique insight into long-term changes in this ecosystem, as well as microbial processes operating at depth in the sediment column. High-resolution seismic reflection data (CHIRP and airgun) combined with numerous long sediment piston cores collected from 2007-2013 demonstrate the enormous promise of Lake Towuti for an ICDP drilling campaign. Well-stratified sequences of up to 150 m thickness, uninterrupted by unconformities or erosional truncation, are present in multiple sub-basins within Towuti, providing ideal sites for long-term environmental, climatic, and limnological reconstructions. Multiproxy analyses of our piston cores document a continuous and detailed record of moisture balance variations in Lake Towuti during the past 60 kyr BP. In detail our datasets show that wet conditions and rainforest ecosystems in central Indonesia persisted during Marine Isotope Stage 3 (MIS3) and the Holocene, and were interrupted by severe

  18. SM1.3 Seismic Centers Data Acquisition: an introduction to Antelope, EarthWorm, SeisComP and their usage around the world

    Science.gov (United States)

    Pesaresi, Damiano; Sleeman, Reinoud

    2010-05-01

    Many medium to big size seismic data centers around the world are facing the same question: which software to use to acquire seismic data in real-time? A home-made or a commercial one? Both choices have pros and cons. The in-house development of software usually requires an increased investment in human resources rather than a financial investment. However, the advantage of fully accomplishing your own needs could be put in danger when the software engineer quits the job! Commercial software offers the advantage of being maintained, but it may require both a considerable financial investment and training. The main seismic software data acquisition suites available nowadays are the public domain SeisComP and EarthWorm packages and the commercial package Antelope. Nanometrics, Guralp and RefTek also provide seismic data acquisition software, but they are mainly intended for single station/network acquisition. Antelope is a software package for real-time acquisition and processing of seismic network data, with its roots in the academic seismological community. The software is developed by Boulder Real Time Technology (BRTT) and commercialized by Kinemetrics. It is used by IRIS affiliates for off-line data processing and it is the main acquisition tool for the USArray program and data centers in Europe like the ORFEUS Data Center, OGS (Italy), ZAMG (Austria), ARSO (Slovenia) and GFU (Czech Republic). SeisComP was originally developed for the GEOFON global network to provide a system for data acquisition, data exchange (SeedLink protocol) and automatic processing. It has evolved into to a widely distributed, networked seismographic system for data acquisition and real-time data exchange over Internet and is supported by ORFEUS as the standard seismic data acquisition tool in Europe. SeisComP3 is the next generation of the software and was developed for the German Indonesian Tsunami Early Warning System (GITEWS). SeisComP is licensed by GFZ (free of charge) and

  19. A 9,000-year-old caribou hunting structure beneath Lake Huron.

    Science.gov (United States)

    O'Shea, John M; Lemke, Ashley K; Sonnenburg, Elizabeth P; Reynolds, Robert G; Abbott, Brian D

    2014-05-13

    Some of the most pivotal questions in human history necessitate the investigation of archaeological sites that are now under water. Nine thousand years ago, the Alpena-Amberley Ridge (AAR) beneath modern Lake Huron was a dry land corridor that connected northeast Michigan to southern Ontario. The newly discovered Drop 45 Drive Lane is the most complex hunting structure found to date beneath the Great Lakes. The site and its associated artifacts provide unprecedented insight into the social and seasonal organization of prehistoric caribou hunting. When combined with environmental and simulation studies, it is suggested that distinctly different seasonal strategies were used by early hunters on the AAR, with autumn hunting being carried out by small groups, and spring hunts being conducted by larger groups of cooperating hunters.

  20. Principles of lake sedimentology

    International Nuclear Information System (INIS)

    Janasson, L.

    1983-01-01

    This book presents a comprehensive outline on the basic sedimentological principles for lakes, and focuses on environmental aspects and matters related to lake management and control-on lake ecology rather than lake geology. This is a guide for those who plan, perform and evaluate lake sedimentological investigations. Contents abridged: Lake types and sediment types. Sedimentation in lakes and water dynamics. Lake bottom dynamics. Sediment dynamics and sediment age. Sediments in aquatic pollution control programmes. Subject index

  1. Temporal variation in fish mercury concentrations within lakes from the western Aleutian Archipelago, Alaska.

    Directory of Open Access Journals (Sweden)

    Leah A Kenney

    Full Text Available We assessed temporal variation in mercury (Hg concentrations of threespine stickleback (Gasterosteus aculeatus from Agattu Island, Aleutian Archipelago, Alaska. Total Hg concentrations in whole-bodied stickleback were measured at two-week intervals from two sites in each of two lakes from June 1 to August 10, 2011 during the time period when lakes were ice-free. Across all sites and sampling events, stickleback Hg concentrations ranged from 0.37-1.07 µg/g dry weight (dw, with a mean (± SE of 0.55 ± 0.01 µg/g dw. Mean fish Hg concentrations declined by 9% during the study period, from 0.57 ± 0.01 µg/g dw in early June to 0.52 ± 0.01 µg/g dw in mid-August. Mean fish Hg concentrations were 6% higher in Loon Lake (0.56 ± 0.01 µg/g dw than in Lake 696 (0.53 ± 0.01 µg/g dw, and 4% higher in males (0.56 ± 0.01 µg/g dw than in females (0.54 ± 0.01 µg/g dw. Loon Lake was distinguished from Lake 696 by the presence of piscivorous waterbirds during the breeding season. Mercury concentrations in stickleback from Agattu Island were higher than would be expected for an area without known point sources of Hg pollution, and high enough to be of concern to the health of piscivorous wildlife.

  2. Temporal variation in fish mercury concentrations within lakes from the western Aleutian Archipelago, Alaska

    Science.gov (United States)

    Kenney, Leah A.; Eagles-Smith, Collin A.; Ackerman, Joshua T.; von Hippel, Frank A.

    2014-01-01

    We assessed temporal variation in mercury (Hg) concentrations of threespine stickleback (Gasterosteus aculeatus) from Agattu Island, Aleutian Archipelago, Alaska. Total Hg concentrations in whole-bodied stickleback were measured at two-week intervals from two sites in each of two lakes from June 1 to August 10, 2011 during the time period when lakes were ice-free. Across all sites and sampling events, stickleback Hg concentrations ranged from 0.37–1.07 µg/g dry weight (dw), with a mean (± SE) of 0.55±0.01 µg/g dw. Mean fish Hg concentrations declined by 9% during the study period, from 0.57±0.01 µg/g dw in early June to 0.52±0.01 µg/g dw in mid-August. Mean fish Hg concentrations were 6% higher in Loon Lake (0.56±0.01 µg/g dw) than in Lake 696 (0.53±0.01 µg/g dw), and 4% higher in males (0.56±0.01 µg/g dw) than in females (0.54±0.01 µg/g dw). Loon Lake was distinguished from Lake 696 by the presence of piscivorous waterbirds during the breeding season. Mercury concentrations in stickleback from Agattu Island were higher than would be expected for an area without known point sources of Hg pollution, and high enough to be of concern to the health of piscivorous wildlife.

  3. WATER QUALITY ASSESSMENT OF LAKE TEXOMA BEACHES, 1999-2001

    Science.gov (United States)

    A biological and inorganic assessment of five beaches on Lake Texoma was conducted from September 1999 through July 2001. Water samples for each beach site were divided into two groups, a swimming season and non-swimming season. Water properties such as temperature, alkalinity,...

  4. Measuring variability in trophic status in the Lake Waco/Bosque River Watershed

    Directory of Open Access Journals (Sweden)

    Rodriguez Angela D

    2008-01-01

    Full Text Available Abstract Background Nutrient management in rivers and streams is difficult due to the spatial and temporal variability of algal growth responses. The objectives of this project were to determine the spatial and seasonal in situ variability of trophic status in the Lake Waco/Bosque River watershed, determine the variability in the lotic ecosystem trophic status index (LETSI at each site as indicators of the system's nutrient sensitivity, and determine if passive diffusion periphytometers could provide threshold algal responses to nutrient enrichment. Methods We used the passive diffusion periphytometer to measure in-situ nutrient limitation and trophic status at eight sites in five streams in the Lake Waco/Bosque River Watershed in north-central Texas from July 1997 through October 1998. The chlorophyll a production in the periphytometers was used as an indicator of baseline chlorophyll a productivity and of maximum primary productivity (MPP in response to nutrient enrichment (nitrogen and phosphorus. We evaluated the lotic ecosystem trophic status index (LETSI using the ratio of baseline primary productivity to MPP, and evaluated the trophic class of each site. Results The rivers and streams in the Lake Waco/Bosque River Watershed exhibited varying degrees of nutrient enrichment over the 18-month sampling period. The North Bosque River at the headwaters (NB-02 located below the Stephenville, Texas wastewater treatment outfall consistently exhibited the highest degree of water quality impact due to nutrient enrichment. Sites at the outlet of the watershed (NB-04 and NB-05 were the next most enriched sites. Trophic class varied for enriched sites over seasons. Conclusion Seasonality played a significant role in the trophic class and sensitivity of each site to nutrients. Managing rivers and streams for nutrients will require methods for measuring in situ responses and sensitivities to nutrient enrichment. Nutrient enrichment periphytometers show

  5. Historical abundance and morphology of Didymosphenia species in Naknek Lake, Alaska

    Science.gov (United States)

    Pite, D.P.; Lane, K.A.; Hermann, A.K.; Spaulding, S.A.; Finney, B.P.

    2009-01-01

    Since the 1980s, nuisance blooms of Didymosphenia geminata (Lyngbye) M. Schmidt have been documented in sites that are warmer and more mesotrophic than historical records indicate. While the invasion of D. geminata in New Zealand is well documented, it is less clear whether nuisance blooms in North America are a new phenomenon. In order to test the hypothesis that D. geminata blooms have increased in recent years, we examined the historical record of this species in sediments of Naknek Lake, in Katmai National Park, Alaska. Chronological control was established by relating the presence of two ash layers to known volcanic eruptions. We identified two species of Didymosphenia within the sediment record: D. geminata and D. clavaherculis (Ehrenberg) Metzeltin et Lange-Bertalot. This is the first published record of D. clavaherculis in North America. We found no statistically significant change in the numerical presence of D. geminata or D. clavaherculis, as a group, in Naknek Lake between the years 1218 and 2003. While there has been no sudden, or recent, increase in abundance of Didymosphenia in Naknek Lake, morphological features of D. geminata populations in Naknek Lake are distinct compared to morphological features of D. geminata in streams containing nuisance blooms from sites in North America and New Zealand. Variance in the morphology of Didymosphenia cells may help determine relationships between distinct sub-populations and establish the history of habitat invasion.

  6. Distribution of acidic and neutral drugs in surface waters near sewage treatment plants in the lower Great Lakes, Canada.

    Science.gov (United States)

    Metcalfe, Chris D; Miao, Xiu-Sheng; Koenig, Brenda G; Struger, John

    2003-12-01

    Prescription and nonprescription drugs have been detected in rivers and streams in Europe and the United States. Sewage treatment plants (STPs) are an important source of these contaminants, but few data exist on the spatial distribution of drugs in surface waters near STPs. Samples of surface water were collected in the summer and fall of 2000 at open-water sites in the lower Great Lakes (Lake Ontario and Lake Erie), at sites near the two STPs for the city of Windsor (ON, Canada), and at sites in Hamilton Harbour (ON, Canada), an embayment of western Lake Ontario that receives discharges from several STPs. In a follow-up study in the summer of 2002, samples of surface water and final effluent from adjacent STPs were collected from sites in Hamilton Harbour and Windsor. In addition, surface water and STP effluent samples were collected in Peterborough (ON, Canada). All samples of surface water and STP effluents were analyzed for selected acidic and neutral drugs. In the survey of Hamilton Harbour and Windsor conducted in 2000, acidic drugs and the antiepileptic drug carbamazepine were detected at ng/L concentrations at sites that were up to 500 m away from the STP, but the hydrological conditions of the receiving waters strongly influenced the spatial distribution of these compounds. Drugs were not detected at open-water locations in western Lake Erie or in the Niagara River near the municipality of Niagara-on-the-Lake (ON, Canada). However, clofibric acid, ketoprofen, fenoprofen, and carbamazepine were detected in samples collected in the summer of 2000 at sites in Lake Ontario and at a site in the Niagara River (Fort Erie, ON, Canada) that were relatively remote from STP discharges. Follow-up studies in the summer of 2002 indicated that concentrations of acidic and neutral drugs in surface waters near the point of sewage discharge into the Little River (ON, Canada) STP were approximately equal to the concentrations in the final effluent from the STP. Caffeine and

  7. Lake Afdera: a threatened saline lake in Ethiopia | Getahun | SINET ...

    African Journals Online (AJOL)

    Lake Afdera is a saline lake located in the Afar region, Northern Ethiopia. Because of its inaccessibility it is one of the least studied lakes of the country. It supports life including three species of fish of which two are endemic. Recently, reports are coming out that this lake is used for salt extraction. This paper gives some ...

  8. AMS radiocarbon analyses from Lake Baikal, Siberia: Challenges of dating sediments from a large, oligotrophic lake

    Science.gov (United States)

    Colman, Steven M.; Jones, Glenn A.; Rubin, M.; King, J.W.; Peck, J.A.; Orem, W.H.

    1996-01-01

    A suite of 146 new accelerator-mass spectrometer (AMS) radiocarbon ages provides the first reliable chronology for late Quaternary sediments in Lake Baikal. In this large, highly oligotrophic lake, biogenic and authigenic carbonate are absent, and plant macrofossils are extremely rare. Total organic carbon is therefore the primary material available for dating. Several problems are associated with the TOC ages. One is the mixture of carbon sources in TOC, not all of which are syndepositional in age. This problem manifests itself in apparent ages for the sediment surface that are greater than zero. However, because most of the organic carbon in Lake Baikal sediments is algal (autochthonous) in origin, this effect is limited to about 1000+500 years, which can be corrected, at least for young deposits. The other major problem with dating Lake Baikal sediments is the very low carbon contents of glacial-age deposits, which makes them extremely susceptible to contamination with modern carbon. This problem can be minimized by careful sampling and handling procedures. The ages show almost an order of magnitude difference in sediment-accumulation rates among different sedimentary environments in Lake Baikal, from about 0.04 mm/year on isolated banks such as Academician Ridge, to nearly 0.3 mm/year in the turbidite depositional areas beneath the deep basin floors, such as the Central Basin. The new AMS ages clearly indicate that the dramatic increase in diatom productivity in the lake, as evidenced by increases in biogenic silica and organic carbon, began about 13 ka, in contrast to previous estimates of 7 ka for the age of this transition. Holocene net sedimentation rates may be less than, equal to, or greater than those in the late Pleistocene, depending on the site. This variability reflects the balance between variable terrigenous sedimentation and increased biogenic sedimentation during interglaciations. The ages reported here, and the temporal and spatial variation in

  9. Report of ground water monitoring for expansion of the golf course, Salt Lake City, Utah, Vitro Processing Site. Revision 0

    International Nuclear Information System (INIS)

    1996-03-01

    Ground water elevations of the shallow unconfined aquifer have been monitored at the Uranium Mill Tailings Remedial Action (UMTRA) Project, Vitro Processing site, Salt Lake City, Utah, for the purposes of characterizing ground water flow conditions and evaluating the effects of irrigation of the golf driving range. Data collected, to date, show that the water table reached its highest level for the year during March and April 1995. From May through July 1995, the water table elevations decreased in most monitor wells due to less precipitation and higher evapotranspiration. Review and evaluation of collected data suggest that irrigation of the golf driving range will have negligible effects on water levels and ground water flow patterns if rates of irrigation do not significantly exceed future rates of evapotranspiration

  10. Modeling Prairie Pothole Lakes: Linking Satellite Observation and Calibration (Invited)

    Science.gov (United States)

    Schwartz, F. W.; Liu, G.; Zhang, B.; Yu, Z.

    2009-12-01

    This paper examines the response of a complex lake wetland system to variations in climate. The focus is on the lakes and wetlands of the Missouri Coteau, which is part of the larger Prairie Pothole Region of the Central Plains of North America. Information on lake size was enumerated from satellite images, and yielded power law relationships for different hydrological conditions. More traditional lake-stage data were made available to us from the USGS Cottonwood Lake Study Site in North Dakota. A Probabilistic Hydrologic Model (PHM) was developed to simulate lake complexes comprised of tens-of-thousands or more individual closed-basin lakes and wetlands. What is new about this model is a calibration scheme that utilizes remotely-sensed data on lake area as well as stage data for individual lakes. Some ¼ million individual data points are used within a Genetic Algorithm to calibrate the model by comparing the simulated results with observed lake area-frequency power law relationships derived from Landsat images and water depths from seven individual lakes and wetlands. The simulated lake behaviors show good agreement with the observations under average, dry, and wet climatic conditions. The calibrated model is used to examine the impact of climate variability on a large lake complex in ND, in particular, the “Dust Bowl Drought” 1930s. This most famous drought of the 20th Century devastated the agricultural economy of the Great Plains with health and social impacts lingering for years afterwards. Interestingly, the drought of 1930s is unremarkable in relation to others of greater intensity and frequency before AD 1200 in the Great Plains. Major droughts and deluges have the ability to create marked variability of the power law function (e.g. up to one and a half orders of magnitude variability from the extreme Dust Bowl Drought to the extreme 1993-2001 deluge). This new probabilistic modeling approach provides a novel tool to examine the response of the

  11. Environmentally relevant chemical mixtures of concern in waters of United States tributaries to the Great Lakes

    Science.gov (United States)

    Elliott, Sarah M.; Brigham, Mark E.; Kiesling, Richard L.; Schoenfuss, Heiko L.; Jorgenson, Zachary G.

    2018-01-01

    The North American Great Lakes are a vital natural resource that provide fish and wildlife habitat, as well as drinking water and waste assimilation services for millions of people. Tributaries to the Great Lakes receive chemical inputs from various point and nonpoint sources, and thus are expected to have complex mixtures of chemicals. However, our understanding of the co‐occurrence of specific chemicals in complex mixtures is limited. To better understand the occurrence of specific chemical mixtures in the US Great Lakes Basin, surface water from 24 US tributaries to the Laurentian Great Lakes was collected and analyzed for diverse suites of organic chemicals, primarily focused on chemicals of concern (e.g., pharmaceuticals, personal care products, fragrances). A total of 181 samples and 21 chemical classes were assessed for mixture compositions. Basin wide, 1664 mixtures occurred in at least 25% of sites. The most complex mixtures identified comprised 9 chemical classes and occurred in 58% of sampled tributaries. Pharmaceuticals typically occurred in complex mixtures, reflecting pharmaceutical‐use patterns and wastewater facility outfall influences. Fewer mixtures were identified at lake or lake‐influenced sites than at riverine sites. As mixture complexity increased, the probability of a specific mixture occurring more often than by chance greatly increased, highlighting the importance of understanding source contributions to the environment. This empirically based analysis of mixture composition and occurrence may be used to focus future sampling efforts or mixture toxicity assessments. 

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

    Science.gov (United States)

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

    1988-01-01

    Lake Austin and Town Lake are located on the Colorado River in Travis County, central Texas, and serve as a source of water for municipal and industrial water supplies, electrical-power generation, and recreation for more than 500,000 people in the Austin metropolitan area. Lake Austin, located immediately downstream of Lake Travis, extends for more than 20 miles into the western edge of the city of Austin. Town Lake extends through the downtown area of the city of Austin for nearly 6 miles where the Colorado River is impounded by Longhorn Dam.

  13. The Lake Bosumtwi impact structure in Ghana: A brief environmental assessment and discussion of ecotourism potential

    Science.gov (United States)

    Boamah, Daniel; Koeberl, Christian

    Lake Bosumtwi is a natural inland freshwater lake that originated from a meteorite impact. The lake is becoming a popular tourist attraction in Ghana and has the potential to be developed as an ecotourism site in the future. However, there have been some unregulated human activities and unplanned infrastructure development, and there are increased levels of pollutants in the lake water. In order to make ecotourism at Lake Bosumtwi successful in the long term, the Lake Bosumtwi Development Committee has been formed to ensure that local people are empowered to mobilize their own capacities. It has been realized that an important criterion required to develop ecotourism in a socially responsible, economically efficient, and environmentally viable way is to foster a constructive dialogue between the local people and tourists about the needs of the indigenous people.

  14. A synthesis of post-glacial diatom records from Lake Baikal

    Science.gov (United States)

    Bradbury, J. Platt; Bezrukova, E.; Chernyaeva, G.; Colman, S.M.; Khursevich, G.; King, J.W.; Likoshway, Ye. V.

    1994-01-01

    The biostratigraphy of fossil diatoms contributes important chronologic, paleolimnologic, and paleoclimatic information from Lake Baikal in southeastern Siberia. Diatoms are the dominant and best preserved microfossils in the sediments, and distinctive assemblages and species provide inter-core correlations throughout the basin at millennial to centennial scales, in both high and low sedimentation-rate environments. Distributions of unique species, once dated by radiocarbon, allow diatoms to be used as dating tools for the Holocene history of the lake.Diatom, pollen, and organic geochemical records from site 305, at the foot of the Selenga Delta, provide a history of paleolimnologic and paleoclimatic changes from the late glacial (15 ka) through the Holocene. Before 14 ka diatoms were very rare, probably because excessive turbidity from glacial meltwater entering the lake impeded productivity. Between 14 and 12 ka, lake productivity increased, perhaps as strong winds promoted deep mixing and nutrient regeneration. Pollen evidence suggests a cold shrub — steppe landscape dominated the central Baikal depression at this time. As summer insolation increased, conifers replaced steppe taxa, but diatom productivity declined between 11 and 9 ka perhaps as a result of increased summer turbidity resulting from violent storm runoff entering the lake via short, steep drainages. After 8 ka, drier, but more continental climates prevailed, and the modern diatom flora of Lake Baikal came to prominence.On Academician Ridge, a site of slow sedimentation rates, Holocene diatom assemblages at the top of 10-m cores reappear at deeper levels suggesting that such cores record at least two previous interglacial (or interstadial?) periods. Nevertheless, distinctive species that developed prior to the last glacial period indicate that the dynamics of nutrient cycling in Baikal and the responsible regional climatic environments were not entirely analogous to Holocene conditions. During

  15. Water sampling using a drone at Yugama crater lake, Kusatsu-Shirane volcano, Japan

    Science.gov (United States)

    Terada, Akihiko; Morita, Yuichi; Hashimoto, Takeshi; Mori, Toshiya; Ohba, Takeshi; Yaguchi, Muga; Kanda, Wataru

    2018-04-01

    Remote sampling of water from Yugama crater lake at Kusatsu-Shirane volcano, Japan, was performed using a drone. Despite the high altitude of over 2000 m above sea level, our simple method was successful in retrieving a 250 mL sample of lake water. The procedure presented here is easy for any researcher to follow who operates a drone without additional special apparatus. We compare the lake water sampled by drone with that sampled by hand at a site where regular samplings have previously been carried out. Chemical concentrations and stable isotope ratios are largely consistent between the two techniques. As the drone can fly automatically with the aid of navigation by Global Navigation Satellite System (GNSS), it is possible to repeatedly sample lake water from the same location, even when entry to Yugama crater lake is restricted due to the risk of eruption.[Figure not available: see fulltext.

  16. Carbon Metabolism in Lake Steinhuder Meer

    International Nuclear Information System (INIS)

    Ernst, D.

    1981-01-01

    Lake Steinhuder Meer is the largest lake in the Northern German plain. It is very shallow (average 1.35 m deep), highly productive and turbid due to a layer of loose sediments rich in organic matter (Ernst et al., 1980). It is an important recreational site, natural resort and still remarkable fishing area. It is fed by 2/3 from subsoil waters and by 1/3 by. rain. The response of the water body to increased nutrient load is investigated by enrichment experiments using plastic bags. Water in plastic bags is in contact with the atmosphere but is separated from the bottom sediment. Hence this technique may also give information about the roles of the sediment and the atmosphere in lake metabolism. Plasticisers may influence the experiment and mechanical damage may restrict the life-time of the facility. After several trials with polyethylene foils we now use a re-enforced PVC-foil. The material (Beneflex L) stands the wave movement for several weeks. Since Steinhuder Meer is not stratified we just pump the water into the bag. The water volume in the container is determined by a water clock

  17. Refuge Lake Reclassification in 620 Minnesota Cisco Lakes under Future Climate Scenarios

    Directory of Open Access Journals (Sweden)

    Liping Jiang

    2017-09-01

    Full Text Available Cisco (Coregonus artedi is the most common coldwater stenothermal fish in Minnesota lakes. Water temperature (T and dissolved oxygen (DO in lakes are important controls of fish growth and reproduction and likely change with future climate warming. Built upon a previous study, this study uses a modified method to identify which of 620 cisco lakes in Minnesota can still support cisco populations under future climate and therefore be classified as cisco refuge lakes. The previous study used oxythermal stress parameter TDO3, the temperature at DO of 3 mg/L, simulated only from deep virtual lakes to classify 620 cisco lakes. Using four categories of virtual but representative cisco lakes in modified method, a one-dimensional water quality model MINLAKE2012 was used to simulate daily T and DO profiles in 82 virtual lakes under the past (1961–2008 and two future climate scenarios. A multiyear average of 31-day largest TDO3 over variable benchmark (VB periods, AvgATDO3VB, was calculated from simulated T and DO profiles using FishHabitat2013. Contour plots of AvgATDO3VB for four categories of virtual lakes were then developed to reclassify 620 cisco lakes into Tier 1 (AvgATDO3VB < 11 °C or Tier 2 refuge lakes, and Tier 3 non-refuge lakes (AvgATDO3VB > 17 °C. About 20% of 620 cisco lakes are projected to be refuge lakes under future climate scenarios, which is a more accurate projection (improving the prediction accuracy by ~6.5% from the previous study since AvgATDO3VB was found to vary by lake categories.

  18. Indicators of Lake Temsah Potential by some heavy metals Heavy Metals in Sediment

    International Nuclear Information System (INIS)

    Abdel Sabour, M.F.; Aly, R.O.; Khalil, M.T.; Attwa, A.H.A.

    1999-01-01

    The Environmental impact of industrial, agricultural and domestic waster on heavy metals sediment content in lake Temsah has been investigated. Seven sites were chosen, differ in nature of activity and quantity of wastes, namely from south to north-west; Arab contractors shipyard workshop(A), The junction between the western logon and the lake(B), El-Temsah workshop (C), El-Temsah shipyard (private workshop) (D), El-Karakat workshop for SCA (E), El-Forsan drain out fall to the lake (F) and SCA Press outlet (G). Eight of heavy metal concentrations of concern (Fe, Mn, Zn, Cu, Co, Ni, Cd and Pb) were estimated in sediment samples collected from different chosen sites during the seasons; summer , autumn 1995 and winter , spring 1996. Results of this study reveal that pollution is directly related to the type of the activity in each site. Sediment samples results showed that the most suffering sites were found to be in the order of B> D> C> G> F, and the least polluted ones were E> A. And the highest polluted season was summer, whereas the least one was winter. It is obvious that the general mean values of Cu, Ni and Cd are exceeding the allowed concentrations documented for diverse trace components in coastal sediments. Strict regulations that must be followed in order to minimize this pollution specially, by heavy metals from marine workshop

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

    Science.gov (United States)

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

    2017-10-01

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

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

    Science.gov (United States)

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

    2014-12-01

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

  1. Exploratory Hydrocarbon Drilling Impacts to Arctic Lake Ecosystems

    Science.gov (United States)

    Thienpont, Joshua R.; Kokelj, Steven V.; Korosi, Jennifer B.; Cheng, Elisa S.; Desjardins, Cyndy; Kimpe, Linda E.; Blais, Jules M.; Pisaric, Michael FJ.; Smol, John P.

    2013-01-01

    Recent attention regarding the impacts of oil and gas development and exploitation has focused on the unintentional release of hydrocarbons into the environment, whilst the potential negative effects of other possible avenues of environmental contamination are less well documented. In the hydrocarbon-rich and ecologically sensitive Mackenzie Delta region (NT, Canada), saline wastes associated with hydrocarbon exploration have typically been disposed of in drilling sumps (i.e., large pits excavated into the permafrost) that were believed to be a permanent containment solution. However, failure of permafrost as a waste containment medium may cause impacts to lakes in this sensitive environment. Here, we examine the effects of degrading drilling sumps on water quality by combining paleolimnological approaches with the analysis of an extensive present-day water chemistry dataset. This dataset includes lakes believed to have been impacted by saline drilling fluids leaching from drilling sumps, lakes with no visible disturbances, and lakes impacted by significant, naturally occurring permafrost thaw in the form of retrogressive thaw slumps. We show that lakes impacted by compromised drilling sumps have significantly elevated lakewater conductivity levels compared to control sites. Chloride levels are particularly elevated in sump-impacted lakes relative to all other lakes included in the survey. Paleolimnological analyses showed that invertebrate assemblages appear to have responded to the leaching of drilling wastes by a discernible increase in a taxon known to be tolerant of elevated conductivity coincident with the timing of sump construction. This suggests construction and abandonment techniques at, or soon after, sump establishment may result in impacts to downstream aquatic ecosystems. With hydrocarbon development in the north predicted to expand in the coming decades, the use of sumps must be examined in light of the threat of accelerated permafrost thaw, and the

  2. Source characterization using compound composition and stable carbon isotope ratio of PAHs in sediments from lakes, harbor, and shipping waterway

    International Nuclear Information System (INIS)

    Kim, Moonkoo; Kennicutt, Mahlon C.; Qian, Yaorong

    2008-01-01

    Molecular compositions and compound specific stable carbon isotope ratios of polycyclic aromatic hydrocarbons (PAH) isolated from sediments were used to characterize possible sources of contamination at an urban lake, a harbor, a shipping waterway, and a relatively undisturbed remote lake in the northwest United States. Total PAH concentrations in urban lake sediments ranged from 66.0 to 16,500 μg g -1 dry wt. with an average of 2600 μg g -1 , which is ∼ 50, 100, and 400 times higher on average than PAH in harbor (48 μg g -1 on average), shipping waterway (26 μg g -1 ), and remote lake (7 μg g -1 ) sediments, respectively. The PAH distribution patterns, methyl phenanthrene/phenanthrene ratios, and a pyrogenic index at the sites suggest a pyrogenic origin for PAHs. Source characterization using principal component analysis and various molecular indices including C2-dibenzothiophenes/C2-phenanthrenes, C3-dibenzothiophenes/C3-phenanthrenes, and C2-chrysenes/C2-phenanthrenes ratios, was able to differentiate PAH deposited in sediments from the four sites. The uniqueness of the source of the sediment PAHs from urban lake was also illustrated by compound specific stable carbon isotope analysis. It was concluded that urban lake sediments are accumulating PAH from sources that are unique from contamination detected at nearby sites in the same watershed

  3. Environmental clustering of lakes to evaluate performance of a macrophyte index of biotic integrity

    Science.gov (United States)

    Vondracek, Bruce C.; Vondracek, Bruce; Hatch, Lorin K.

    2013-01-01

    Proper classification of sites is critical for the use of biological indices that can distinguish between natural and human-induced variation in biological response. The macrophyte-based index of biotic integrity was developed to assess the condition of Minnesota lakes in relation to anthropogenic stressors, but macrophyte community composition varies naturally across the state. The goal of the study was to identify environmental characteristics that naturally influence macrophyte index response and establish a preliminary lake classification scheme for biological assessment (bioassessment). Using a comprehensive set of environmental variables, we identified similar groups of lakes by clustering using flexible beta classification. Variance partitioning analysis of IBI response indicated that evaluating similar lake clusters could improve the ability of the macrophyte index to identify community change to anthropogenic stressors, although lake groups did not fully account for the natural variation in macrophyte composition. Diagnostic capabilities of the index could be improved when evaluating lakes with similar environmental characteristics, suggesting the index has potential for accurate bioassessment provided comparable groups of lakes are evaluated.

  4. Monitoring and Assessment of Hydrological and Ecological Changes in Lake Manyas

    Science.gov (United States)

    Curebal, Isa; Efe, Recep; Soykan, Abdullah; Sonmez, Suleyman

    2014-05-01

    Manyas Lake in the northwest of Turkey occupies an area of 165 square kilometers. The surface area of the lake is continuously changing due to human activities, hydrologic and climatic conditions. The objective of this study is to examine the changes in water level and the area of lake and the effects of these changes on the lake's ecosystem and human economic activities. In order to determine the changes lake level measurement data, 1/25000 scale topography maps, rainfall and temperature data and bathymetry maps were used and elevation models were made. During the study period the water level fluctuated between 14.0 and 17.8 meters, and surface area changed between 124,8 km2 and 170,6 km2 respectively. Prior to the construction of a flood barrier at the southern end of the lake in 1992 the maximum surface area of the lake was calculated at 209 km2. Lake Manyas is an important wetland on the route of migration of birds from/to Europe and Africa. 64 ha of the lake and its surroundings along with the entire National Park is a Ramsar site. Irrigated and dry farming is practiced around the lake and fishing is important economic activity. The changes in the water level as result of natural and human factors brought about negative effects on the lake's ecosystem in last ten years. Result of these effects, natural fluctuation of the lake changed and the marshes around the lake destroyed and the bird population decreased. Lowering the water level in the lake is also significantly reduced the number of fish and number of migratory birds. The construction of the flood barrier destroyed vegetation and bird life in about a 25% of area of the lake on the south. The natural ecosystem in this area has been adversely affected. Moreover, when the water level is low due to low rain fall and irrigation, vegetation on the lake's shore line dies and some areas turn to swamp. The fauna and flora are negatively affected by water level changes particularly in the protected National Park

  5. Large Lakes Dominate CO2 Evasion From Lakes in an Arctic Catchment

    Science.gov (United States)

    Rocher-Ros, Gerard; Giesler, Reiner; Lundin, Erik; Salimi, Shokoufeh; Jonsson, Anders; Karlsson, Jan

    2017-12-01

    CO2 evasion from freshwater lakes is an important component of the carbon cycle. However, the relative contribution from different lake sizes may vary, since several parameters underlying CO2 flux are size dependent. Here we estimated the annual lake CO2 evasion from a catchment in northern Sweden encompassing about 30,000 differently sized lakes. We show that areal CO2 fluxes decreased rapidly with lake size, but this was counteracted by the greater overall coverage of larger lakes. As a result, total efflux increased with lake size and the single largest lake in the catchment dominated the CO2 evasion (53% of all CO2 evaded). By contrast, the contribution from the smallest ponds (about 27,000) was minor (evasion at the landscape scale.

  6. Lake Michigan lake trout PCB model forecast post audit

    Science.gov (United States)

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

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

    Science.gov (United States)

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

    2015-12-01

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

  8. Silver contamination on abiotic and biotic compartments of Nahuel Huapi National Park lakes, Patagonia, Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro Guevara, Sergio; Arribere, Maria; Bubach, Debora; Vigliano, Pablo; Rizzo, Andrea; Alonso, Marcelo; Sanchez, Ricardo

    2005-01-05

    The Ag contents of abiotic and biotic compartments of different lakes of Nahuel Huapi National Park, Patagonia, Argentina were analyzed. The water bodies studied were lakes Nahuel Huapi, Moreno, Escondido, Espejo Chico and Traful, the latter chosen as a reference lake. The Ag concentration profiles of short sediment cores, dated by {sup 210}Pb and {sup 137}Cs techniques, were analyzed, as well as suspended load collected from three sites of lake Nahuel Huapi. The biota studied were the native mussel Diplodon chilensis (digestive gland and total soft tissues pooled samples) and five species of fish, two native and three introduced (liver and muscle pooled samples). Ag contents were determined by Instrumental Neutron Activation Analysis (INAA). The upper layers of the sediment cores sampled in lake Nahuel Huapi were enriched in Ag contents compared to deep layers in accumulation periods corresponding to the second half of the 20th century, but this enrichment was neither observed in the reference lake Traful, nor in lakes Espejo Chico and Escondido. Ag was enriched over background level (0.1 {mu}g g{sup -1}) also in suspended load collected in lake Nahuel Huapi. Ag fluxes to sediments were computed for suspended load and enriched sediment core layers. Highest Ag fluxes, from 350 to 470 {mu}g m{sup -2} year{sup -1}, were measured in Nahuel Huapi near the site where the liquid effluents of the Bariloche city sewage treatment plant are released to the lake. The spatial distribution of the other Ag fluxes suggests that this is the main source of Ag to lake Nahuel Huapi and lateral transport occurs within the water body. Ag concentrations on biota samples were consistent with these conclusions. Mussels collected in lake Nahuel Huapi showed higher Ag concentrations than in the other lakes, especially when compared to lake Traful. Ag contents in mussels were strongly associated with sediment intake, but enriched probably due to sediment grain size sorting during the intake

  9. The Influence of Macrophytes on Sediment Resuspension and the Effect of Associated Nutrients in a Shallow and Large Lake (Lake Taihu, China)

    Science.gov (United States)

    Zhu, Mengyuan; Zhu, Guangwei; Nurminen, Leena; Wu, Tingfeng; Deng, Jianming; Zhang, Yunlin; Qin, Boqiang; Ventelä, Anne-Mari

    2015-01-01

    A yearlong campaign to examine sediment resuspension was conducted in large, shallow and eutrophic Lake Taihu, China, to investigate the influence of vegetation on sediment resuspension and its nutrient effects. The study was conducted at 6 sites located in both phytoplankton-dominated zone and macrophyte-dominated zone of the lake, lasting for a total of 13 months, with collections made at two-week intervals. Sediment resuspension in Taihu, with a two-week high average rate of 1771 g·m-2·d-1 and a yearly average rate of 377 g·m-2·d-1, is much stronger than in many other lakes worldwide, as Taihu is quite shallow and contains a long fetch. The occurrence of macrophytes, however, provided quite strong abatement of sediment resuspension, which may reduce the sediment resuspension rate up to 29-fold. The contribution of nitrogen and phosphorus to the water column from sediment resuspension was estimated as 0.34 mg·L-1 and 0.051 mg·L-1 in the phytoplankton-dominated zone. Sediment resuspension also largely reduced transparency and then stimulated phytoplankton growth. Therefore, sediment resuspension may be one of the most important factors delaying the recovery of eutrophic Lake Taihu, and the influence of sediment resuspension on water quality must also be taken into account by the lake managers when they determine the restoration target. PMID:26030094

  10. Groundwater flux and nutrient loading in the northeast section of Bear Lake, Muskegon County, Michigan, 2015

    Science.gov (United States)

    Totten, Alexander R.; Maurer, Jessica A.; Duris, Joseph W.

    2017-11-30

    Bear Lake in North Muskegon, Michigan, is listed as part of the Muskegon Lake area of concern as designated by the U.S. Environmental Protection Agency. This area of concern was designated as a result of eutrophication and beneficial use impairments. On the northeast end of Bear Lake, two man-made retention ponds (Willbrandt Pond East and Willbrandt Pond West), formerly used for celery farming, may contribute nutrients to Bear Lake. Willbrandt Ponds (East and West) were previously muck fields that were actively used for celery farming from the early 1900s until 2002. The restoration and reconnection of the Willbrandt Ponds into Bear Lake prompted concerns of groundwater nutrient loading into Bear Lake. Studies done by the State of Michigan and Grand Valley State University revised initial internal phosphorus load estimates and indicated an imbalance in the phosphorus budget in Bear Lake. From June through November 2015, the U.S. Geological Survey (USGS) did an investigative study to quantify the load of nutrients from shallow groundwater around the Willbrandt Ponds in an effort to update the phosphorus budget to Bear Lake. Seven sampling locations were established, including five shallow groundwater wells and two surface-water sites, in the Willbrandt pond study area and Bear Lake. A total of 12 nutrient samples and discrete water-level measurements were collected from each site from June through November 2015. Continuous water-level data were recorded for both surface-water monitoring locations for the entire sampling period.Water-level data indicated that Willbrandt Pond West had the highest average water-level elevation of all sites monitored, which indicated the general direction of flux is from Willbrandt Pond West to Bear Lake. Nutrient and chloride loading from Willbrandt Pond West to Bear Lake was calculated using two distinct methods: Dupuit and direct seepage methods. Shallow groundwater loading calculations were determined by using groundwater levels to

  11. Advanced reservoir characterization in the Antelope Shale to establish the viability of CO2 enhanced oil recovery in California`s Monterey Formation siliceous shales. Annual report, February 7, 1997--February 6, 1998

    Energy Technology Data Exchange (ETDEWEB)

    Morea, M.F.

    1998-06-01

    The primary objective of this research is to conduct advanced reservoir characterization and modeling studies in the Antelope Shale reservoir. Characterization studies will be used to determine the technical feasibility of implementing a CO{sub 2} enhanced oil recovery project in the antelope Shale in Buena Vista Hills Field. The proposed pilot consists of four existing producers on 20 acre spacing with a new 10 acre infill well drilled as the pilot CO{sub 2} injector. Most of the reservoir characterization during Phase 1 of the project will be performed using data collected in the pilot pattern wells. During this period the following tasks have been completed: laboratory wettability; specific permeability; mercury porosimetry; acoustic anisotropy; rock mechanics analysis; core description; fracture analysis; digital image analysis; mineralogical analysis; hydraulic flow unit analysis; petrographic and confocal thin section analysis; oil geochemical fingerprinting; production logging; carbon/oxygen logging; complex lithologic log analysis; NMR T2 processing; dipole shear wave anisotropy logging; shear wave vertical seismic profile processing; structural mapping; and regional tectonic synthesis. Noteworthy technological successes for this reporting period include: (1) first (ever) high resolution, crosswell reflection images of SJV sediments; (2) first successful application of the TomoSeis acquisition system in siliceous shales; (3) first detailed reservoir characterization of SJV siliceous shales; (4) first mineral based saturation algorithm for SJV siliceous shales, and (5) first CO{sub 2} coreflood experiments for siliceous shale. Preliminary results from the CO{sub 2} coreflood experiments (2,500 psi) suggest that significant oil is being produced from the siliceous shale.

  12. Tools for the development of a benthic quality index for Italian lakes

    Directory of Open Access Journals (Sweden)

    Angelo SOLIMINI

    2006-02-01

    , the mean of these three variables was calculated for each taxon (mean BQIW. Third, the mean BQIW was multiplied by taxa abundance and divided by the total number of specimens present at each site for which the BQIL was obtained. Using a regression between BQIL and TSI values, lake sites were assigned to 5 quality classes as required by the Italian Law 152/99 and the WFD 2000/60/CE. This assignment must be considered as tentative, because different lake types should be considered separately to develop an index. At present the lack of information from different lake typologies hinders the development of a more sophisticated index such as the French Lake Biotic Index (LBI.

  13. Species composition, abundance and distribution of zooplankton in a tropical eutrophic lake: Lake Catemaco, México

    OpenAIRE

    Roberto E. Torres-Orozco B.; Sandra A. Zanatta

    1998-01-01

    From April 1992 to May 1993, zooplankton samples were collected monthly by means of horizontal tows in nine sites of the lake. Prior to the towing, temperature of surface water, transparency (Secchi), pH and dissolved oxygen were evaluated. A total of 31 zooplankton forms, including 14 species of rotifers, three copepods, five cladocerans and one ostracod, as well as protozoans (mainly vorticellids and ciliates), were detected. Rotifers were the dominant organisms, mainly Brachionus havanaens...

  14. Pathology and immunohistochemistry of papillomavirus-associated cutaneous lesions in Cape mountain zebra, giraffe, sable antelope and African buffalo in South Africa

    Directory of Open Access Journals (Sweden)

    J. H. Williams

    2011-04-01

    Full Text Available Skin lesions associated with papillomaviruses have been reported in many animal species and man. Bovine papillomavirus (BVP affects mainly the epidermis, but also the dermis in several species including bovine, the best-known example being equine sarcoid, which is associated with BVP types 1 and 2. This publication describes and illustrates the macroscopic and histological appearance of BPV-associated papillomatous, fibropapillomatous or sarcoid-like lesions in Cape mountain zebra (Equus zebra zebra from the Gariep Dam Nature Reserve, 2 giraffes (Giraffa camelopardalis from the Kruger National Park, and a sable antelope (Hippotragus niger from the Kimberley area of South Africa. An African buffalo (Syncerus caffer cow from Kruger National Park also had papillomatous lesions but molecular characterisation of lesional virus was not done. Immunohistochemical staining using polyclonal rabbit antiserum to chemically disrupted BPV-1, which cross-reacts with the L1 capsid of most known papillomaviruses, was positive in cells of the stratum granulosum of lesions in Giraffe 1, the sable and the buffalo and negative in those of the zebra and Giraffe 2. Fibropapillomatous and sarcoid-like lesions from an adult bovine were used as positive control for the immunohistochemistry and are described and the immunohistochemistry illustrated for comparison. Macroscopically, both adult female giraffe had severely thickened multifocal to coalescing nodular and occasionally ulcerated lesions of the head, neck and trunk with local poorly-circumscribed invasion into the subcutis. Necropsy performed on the 2nd giraffe revealed neither internal metastases nor serious underlying disease. Giraffe 1 had scattered, and Giraffe 2 numerous, large, anaplastic, at times indistinctly multinucleated dermal fibroblasts with bizarre nuclei within the sarcoid-like lesions, which were BPV-1 positive in Giraffe 1 and BPV-1 and -2 positive in Giraffe 2 by RT-PCR. The sable antelope

  15. Chronic genetic damages in Geophagus brasiliensis exposed to anthropic impact in estuarine lakes at Santa Catarina coast--southern of Brazil.

    Science.gov (United States)

    Benincá, Cristiane; Ramsdorf, Wanessa; Vicari, Taynah; de Oliveira Ribeiro, Ciro A; de Almeida, Marina I; Silva de Assis, Helena C; Cestari, Marta Margarete

    2012-04-01

    Biological monitoring through animals exposed to pollutants using biomarkers provides a promising tool for the identification of pollutants that may cause damage to human health and/or to sustainability of ecosystems. The effects of pollutants in fish tissues are important tools to understand the impact of human activities in natural ecosystems. The aim of this work was to study the water quality of two estuarine lakes in Santa Catarina, Brazil (Camacho Lake and Santa Marta Lake). Geophagus brasiliensis is a species widely distributed in Brazil and was used in this work. Comet assays in peripheral red blood and kidney cells, micronucleus tests in peripheral red blood cells, measurements of acetylcholinesterase activity in axial muscle and histopathological analysis of liver were used as biomarkers. Three sampling campaigns were undertaken in November 2004, June 2005 and November 2005. Thirty adult animals were sampled from each of three different sites (P1--Santa Marta Lake, P2 and P3--Camacho Lake). A negative control was sampled in a non-polluted site at Costa Ecological Park, Paraná. The positive control for genotoxicity was obtained by treating animals with copper sulphate. The results showed that both studied lakes are impacted by potential genotoxic substances. Severe lesions in liver of G. brasiliensis were also observed. The inhibition of acetylcholinesterase activity suggests the presence of pesticides or metals in the studied sites. This work shows that the water quality of Santa Marta and Camacho Lakes have been compromised and further control source of pollutants into these ecosystems is required.

  16. Precipitation and lake-level changes in the West and Midwest over the past 10,000 to 24,000 years. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Webb, T. III; Street, F.A.; Howe, S.

    1980-02-04

    The goal of the research described in this report is to document the climatic variability over the past 10,000 to 20,000 years in areas in which sites may be designated for the burial of nuclear wastes. Three separate data sets were studied, and the results are presented in three chapters. The first data set consisted of radiocarbon dates documenting past changes in lake levels in lakes and playas in the western United States. The sites were mapped where water levels were higher than the levels today and were presented in a table telling what evidence is available at each site. The lake-level fluctuations for the past 24,000 years at sites in the West were also mapped and time series for these fluctuations at four sites were presented. The second data set was a selection of the published radiocarbon-dated pollen diagrams from the western United States. These data are a valuable source of climatic information and complement the geological evidence of lake-level fluctuations in the West. A table is presented that gives the location, elevation, and number of radiocarbon dates for each site. The third data set was a set of fossil pollen data from 20 sites in the upper Midwest. These data were calibrated in terms of precipitation changes over the past 10,000 years, and maps are presented of the estimated precipitation changes between 10,000 and 7000 years ago and between 7000 years ago and today.

  17. Precipitation and lake-level changes in the West and Midwest over the past 10,000 to 24,000 years. Final report

    International Nuclear Information System (INIS)

    Webb, T. III; Street, F.A.; Howe, S.

    1980-01-01

    The goal of the research described in this report is to document the climatic variability over the past 10,000 to 20,000 years in areas in which sites may be designated for the burial of nuclear wastes. Three separate data sets were studied, and the results are presented in three chapters. The first data set consisted of radiocarbon dates documenting past changes in lake levels in lakes and playas in the western United States. The sites were mapped where water levels were higher than the levels today and were presented in a table telling what evidence is available at each site. The lake-level fluctuations for the past 24,000 years at sites in the West were also mapped and time series for these fluctuations at four sites were presented. The second data set was a selection of the published radiocarbon-dated pollen diagrams from the western United States. These data are a valuable source of climatic information and complement the geological evidence of lake-level fluctuations in the West. A table is presented that gives the location, elevation, and number of radiocarbon dates for each site. The third data set was a set of fossil pollen data from 20 sites in the upper Midwest. These data were calibrated in terms of precipitation changes over the past 10,000 years, and maps are presented of the estimated precipitation changes between 10,000 and 7000 years ago and between 7000 years ago and today

  18. Lithic technology of the “St Site Complex” from Peninj (Lake Natron, Tanzania: Analysis of an African Oldowan assemblage

    Directory of Open Access Journals (Sweden)

    de la Torre Sáinz, Ignacio

    2004-06-01

    Full Text Available In this work a sistematic analysis of the lithic materials from the ST Site Complex (Lake Natron, Tanzania is presented. This complex is composed of a cluster of eleven archaeological sites, which share a topographic proximity and the same stratigraphic position. They are located above Tuff 1 in the Upper Sandy Clays of the Humbu Formation of Peninj, dated around 1,6-1,4 ma. Lithic artefacts from each archaeological site will be analysed together from a technological perspective, focusing on the relevance of the conclusions obtained for knowledge of the African Oldowan.

    En este trabajo se presenta un análisis sistemático de los materiales líticos hasta ahora estudiados en el Complejo ST de Peninj, en el lago Natron (Tanzania. Este complejo está constituido por un grupo de 11 yacimientos arqueológicos muy próximos topográficamente y situados en la misma posición estratigráfica, por encima de la Toba 1 en las Upper Sandy Cáliz (Arcillas Arenosas Superiores de la Formación Humbu de Peninj, cuya cronología se estima entre los 1,6-1,4 ma. Desde una perspectiva tecnológica, se estudiarán conjuntamente los objetos líticos recuperados en cada uno de estos yacimientos, incidiendo en la relevancia de las conclusiones obtenidas para el conocimiento del Olduvayense africano.

  19. Water Data Analysis 393937093090901 TURKEY CREEK NR SUMNER MO, FULBRIGHT RD NEAR SWAN LAKE NWR-2013-2016

    Data.gov (United States)

    Department of the Interior — WATER MONITORING STATION ANALYSIS – CALENDAR YEAR 2013 to 2016 SITE NUMBER: 393937093090901 SITE NAME: Turkey Creek nr Sumner MO, Fulbright Rd COOPERATION: Swan Lake...

  20. Tides and lake-level variations in the great Patagonian lakes: Observations, modelling and geophysical implications.

    Science.gov (United States)

    Marderwald, Eric; Richter, Andreas; Horwath, Martin; Hormaechea, Jose Luis; Groh, Andreas

    2016-04-01

    In Patagonia, the glacial-isostatic adjustment (GIA) to past ice-mass changes (Ivins & James 2004; Klemann et al. 2007) is of particular interest in the context of the determination of the complex regional rheology related to plate subduction in a triple-junction constellation. To further complicate the situation, GIA is overlaid with load deformation not only due to present ice mass changes but also due to water-level changes in the lakes surrounding the icefields and the ocean surrounding Patagonia. These elastic deformations affect the determination of glacial-isostatic uplift rates from GPS observations (Dietrich et al. 2010; Lange et al. 2014). Observations of lake tides and their comparison with the theoretical tidal signal have been used previously to validate predictions of ocean tidal loading and have revealed regional deviations from conventional global elastic earth models (Richter et al. 2009). In this work we investigate the tides and lake-level variations in Lago Argentino, Lago Viedma, Lago San Martín/O'Higgins and Lago Buenos Aires/General Carrera. This allows us to test, among other things, the validity of tidal loading models. We present pressure tide-gauge records from two sites in Lago Argentino extending over 2.5 years (Richter et al. 2015). These observations are complemented by lake-level records provided by the Argentine National Hydrometeorological Network. Based on these lake-level time series the principal processes affecting the lake level are identified and quantified. Lake-level changes reflecting variations in lake volume are dominated by a seasonal cycle exceeding 1 m in amplitude. Lake-volume changes occur in addition with a daily period in response to melt water influx from surrounding glaciers. In Lago Argentino sporadic lake-volume jumps are caused by bursting of the ice dam of Perito Moreno glacier. Water movements in these lakes are dominated by surface seiches reaching 20 cm in amplitude. A harmonic tidal analysis of the lake

  1. 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...

  2. Relation between physico-chemical limnology and crustacean community in Wular Lake of Kashmir Himalaya.

    Science.gov (United States)

    Shah, Javaid Ahmad; Pandit, Ashok K

    2013-10-01

    The present study scrutinizes the seasonal variation in the distribution of crustacean zooplankton in relation to physico-chemical liminology of Wular lake. Water samples were collected from five study sites during September 2010-August 2011. Remarkable spatial and temporal variations were observed among the different study sites. Among the parameters recorded water temperature showed positive correlation with pH (p<0.01) and orthophosphate (p<0.05).Transparency showed a significant negative correlation with total alkalinity (p<0.01), free carbon dioxide (p<0.01) and ammonical nitrogen (p<0.01). Crustacean zooplankton were collected by filtering 100 L lake water through a 30 microm nytal mesh and preserved in 4% formalin. A total of 42 taxa of crustacean were recorded, among them 23 species belonged to Cladocera, 16 to Copepoda and only 3 to Ostracoda. Species diversity and density depicted an abrupt up surge on the advent of warmer period (extending from March). Among the various sites a maximum of 40 species were recorded from a single biotope (site III) against the minimum of only 17 species being recorded from site I. Bray-Curtis cluster analysis showed close similarity (0.928-0.944%) between summer and autumn in terms of species diversity. Pearson correlation coefficient of the various physico-chemical parameters of water with crustacean zooplankton depicted that not only a single but multiple factors govern over the distribution and diversity of crustacean in the lake.

  3. Lipid biomarkers in Holocene and glacial sediments from ancient Lake Ohrid (Macedonia, Albania

    Directory of Open Access Journals (Sweden)

    J. Holtvoeth

    2010-11-01

    Full Text Available Organic matter preserved in Lake Ohrid sediments originates from aquatic and terrestrial sources. Its variable composition reflects climate-controlled changes in the lake basin's hydrology and related organic matter export, i.e. changes in primary productivity, terrestrial plant matter input and soil erosion. Here, we present first results from lipid biomarker investigations of Lake Ohrid sediments from two near-shore settings: site Lz1120 near the southern shore, with low-lying lands nearby and probably influenced by river discharge, and site Co1202 which is close to the steep eastern slopes. Variable proportions of terrestrial n-alkanoic acids and n-alkanols as well as compositional changes of ω-hydroxy acids document differences in soil organic matter supply between the sites and during different climate stages (glacial, Holocene, 8.2 ka cooling event. Changes in the vegetation cover are suggested by changes in the dominant chain length of terrestrial n-alkanols. Effective microbial degradation of labile organic matter and in situ contribution of organic matter derived from the microbes themselves are both evident in the sediments. We found evidence for anoxic conditions within the photic zone by detecting epicholestanol and tetrahymanol from sulphur-oxidising phototrophic bacteria and bacterivorous ciliates and for the influence of a settled human community from the occurrence of coprostanol, a biomarker for human and animal faeces (pigs, sheep, goats, in an early Holocene sample. This study illustrates the potential of lipid biomarkers for future environmental reconstructions using one of Europe's oldest continental climate archives, Lake Ohrid.

  4. Radioactive material in the West Lake Landfill: Summary report

    International Nuclear Information System (INIS)

    1988-06-01

    The West Lake Landfill is located near the city of St. Louis in Bridgeton, St. Louis County, Missouri. The site has been used since 1962 for disposing of municipal refuse, industrial solid and liquid wastes, and construction demolition debris. This report summarizes the circumstances of the radioactive material in the West Lake Landfill. The radioactive material resulted from the processing of uranium ores and the subsequent by the AEC of processing residues. Primary emphasis is on the radiological environmental aspects as they relate to potential disposition of the material. It is concluded that remedial action is called for. 8 refs., 2 figs., 1 tab

  5. Methane bubbling from northern lakes: present and future contributions to the global methane budget.

    Science.gov (United States)

    Walter, Katey M; Smith, Laurence C; Chapin, F Stuart

    2007-07-15

    Large uncertainties in the budget of atmospheric methane (CH4) limit the accuracy of climate change projections. Here we describe and quantify an important source of CH4 -- point-source ebullition (bubbling) from northern lakes -- that has not been incorporated in previous regional or global methane budgets. Employing a method recently introduced to measure ebullition more accurately by taking into account its spatial patchiness in lakes, we estimate point-source ebullition for 16 lakes in Alaska and Siberia that represent several common northern lake types: glacial, alluvial floodplain, peatland and thermokarst (thaw) lakes. Extrapolation of measured fluxes from these 16 sites to all lakes north of 45 degrees N using circumpolar databases of lake and permafrost distributions suggests that northern lakes are a globally significant source of atmospheric CH4, emitting approximately 24.2+/-10.5Tg CH4yr(-1). Thermokarst lakes have particularly high emissions because they release CH4 produced from organic matter previously sequestered in permafrost. A carbon mass balance calculation of CH4 release from thermokarst lakes on the Siberian yedoma ice complex suggests that these lakes alone would emit as much as approximately 49000Tg CH4 if this ice complex was to thaw completely. Using a space-for-time substitution based on the current lake distributions in permafrost-dominated and permafrost-free terrains, we estimate that lake emissions would be reduced by approximately 12% in a more probable transitional permafrost scenario and by approximately 53% in a 'permafrost-free' Northern Hemisphere. Long-term decline in CH4 ebullition from lakes due to lake area loss and permafrost thaw would occur only after the large release of CH4 associated thermokarst lake development in the zone of continuous permafrost.

  6. PeRL: a circum-Arctic Permafrost Region Pond and Lake database

    Science.gov (United States)

    Muster, Sina; Roth, Kurt; Langer, Moritz; Lange, Stephan; Cresto Aleina, Fabio; Bartsch, Annett; Morgenstern, Anne; Grosse, Guido; Jones, Benjamin; Sannel, A. Britta K.; Sjöberg, Ylva; Günther, Frank; Andresen, Christian; Veremeeva, Alexandra; Lindgren, Prajna R.; Bouchard, Frédéric; Lara, Mark J.; Fortier, Daniel; Charbonneau, Simon; Virtanen, Tarmo A.; Hugelius, Gustaf; Palmtag, Juri; Siewert, Matthias B.; Riley, William J.; Koven, Charles D.; Boike, Julia

    2017-06-01

    Ponds and lakes are abundant in Arctic permafrost lowlands. They play an important role in Arctic wetland ecosystems by regulating carbon, water, and energy fluxes and providing freshwater habitats. However, ponds, i.e., waterbodies with surface areas smaller than 1. 0 × 104 m2, have not been inventoried on global and regional scales. The Permafrost Region Pond and Lake (PeRL) database presents the results of a circum-Arctic effort to map ponds and lakes from modern (2002-2013) high-resolution aerial and satellite imagery with a resolution of 5 m or better. The database also includes historical imagery from 1948 to 1965 with a resolution of 6 m or better. PeRL includes 69 maps covering a wide range of environmental conditions from tundra to boreal regions and from continuous to discontinuous permafrost zones. Waterbody maps are linked to regional permafrost landscape maps which provide information on permafrost extent, ground ice volume, geology, and lithology. This paper describes waterbody classification and accuracy, and presents statistics of waterbody distribution for each site. Maps of permafrost landscapes in Alaska, Canada, and Russia are used to extrapolate waterbody statistics from the site level to regional landscape units. PeRL presents pond and lake estimates for a total area of 1. 4 × 106 km2 across the Arctic, about 17 % of the Arctic lowland ( pangaea.de/10.1594/PANGAEA.868349" target="_blank">https://doi.pangaea.de/10.1594/PANGAEA.868349.

  7. Aquatic macrophyte richness in Danish lakes in relation to alkalinity, transparency, and lake area

    DEFF Research Database (Denmark)

    Vestergaard, Ole Skafte; Sand-Jensen, Kaj

    2000-01-01

    We examined the relationship between environmental factors and the richness of submerged macrophytes species in 73 Danish lakes, which are mainly small, shallow, and have mesotrophic to hypertrophic conditions. We found that mean species richness per lake was only 4.5 in acid lakes of low...... alkalinity but 12.3 in lakes of high alkalinity due to a greater occurrence of the species-rich group of elodeids. Mean species richness per lake also increased significantly with increasing Secchi depth. No significant relationship between species richness and lake surface area was observed among the entire...... group of lakes or a subset of eutrophic lakes, as the growth of submerged macrophytes in large lakes may be restricted by wave action in shallow water and light restriction in deep water. In contrast, macrophyte species richness increased with lake surface area in transparent lakes, presumably due...

  8. Steel Creek primary producers: Periphyton and seston, L-Lake/Steel Creek Biological Monitoring Program, January 1986--December 1991

    Energy Technology Data Exchange (ETDEWEB)

    Bowers, J.A. [Westinghouse Savannah River Co., Aiken, SC (United States); Toole, M.A.; van Duyn, Y. [Normandeau Associates Inc., New Ellenton, SC (United States)

    1992-02-01

    The Savannah River Site (SRS) encompasses 300 sq mi of the Atlantic Coastal Plain in west-central South Carolina. Five major tributaries of the Savannah River -- Upper Three Runs Creek, Four Mile Creek, Pen Branch, Steel Creek, and Lower Three Runs Creek -- drain the site. In 1985, L Lake, a 400-hectare cooling reservoir, was built on the upper reaches of Steel Creek to receive effluent from the restart of L-Reactor and to protect the lower reaches from thermal impacts. The Steel Creek Biological Monitoring Program was designed to assess various components of the system and identify and changes due to the operation of L-Reactor or discharge from L Lake. An intensive ecological assessment program prior to the construction of the lake provided baseline data with which to compare data accumulated after the lake was filled and began discharging into the creek. The Department of Energy must demonstrate that the operation of L-Reactor will not significantly alter the established aquatic ecosystems. This report summarizes the results of six years` data from Steel Creek under the L-Lake/Steel Creek Monitoring Program. L Lake is discussed separately from Steel Creek in Volumes NAI-SR-138 through NAI-SR-143.

  9. Steel Creek primary producers: Periphyton and seston, L-Lake/Steel Creek Biological Monitoring Program, January 1986--December 1991

    International Nuclear Information System (INIS)

    Bowers, J.A.; Toole, M.A.; van Duyn, Y.

    1992-02-01

    The Savannah River Site (SRS) encompasses 300 sq mi of the Atlantic Coastal Plain in west-central South Carolina. Five major tributaries of the Savannah River -- Upper Three Runs Creek, Four Mile Creek, Pen Branch, Steel Creek, and Lower Three Runs Creek -- drain the site. In 1985, L Lake, a 400-hectare cooling reservoir, was built on the upper reaches of Steel Creek to receive effluent from the restart of L-Reactor and to protect the lower reaches from thermal impacts. The Steel Creek Biological Monitoring Program was designed to assess various components of the system and identify and changes due to the operation of L-Reactor or discharge from L Lake. An intensive ecological assessment program prior to the construction of the lake provided baseline data with which to compare data accumulated after the lake was filled and began discharging into the creek. The Department of Energy must demonstrate that the operation of L-Reactor will not significantly alter the established aquatic ecosystems. This report summarizes the results of six years' data from Steel Creek under the L-Lake/Steel Creek Monitoring Program. L Lake is discussed separately from Steel Creek in Volumes NAI-SR-138 through NAI-SR-143

  10. Selecting Suitable Sites for Wind Energy Development in Ghana*

    African Journals Online (AJOL)

    Michae O. Mensah

    2016-06-01

    Jun 1, 2016 ... Ghana's wind power potential both on-shore and off-shore. ..... such as forest and game reserves, tourist sites, etc. (iv) Siting in lakes is restricted. (v) Slopes greater than 30° ... Atlantic coastline that stretches 560 km along the.

  11. Soil Fertility in relation to Landscape Position and Land Use/Cover Types: A Case Study of the Lake Kivu Pilot Learning Site

    Directory of Open Access Journals (Sweden)

    Majaliwa Mwanjalolo Jackson-Gilbert

    2015-01-01

    Full Text Available This study determined the change and distribution of land-uses/covers along the landscape, and evaluated the nutrient status of the top soil layer in the Lake Kivu Pilot Learning Site (LKPLS benchmarked micro-catchments. Soil physical and chemical properties were quantified using triplicate soil samples collected from each land-use/cover at two depths (0–15 and 15–30 cm in three LK PLS Learning Innovation Platform (IP sites (Bufundi in Uganda, Mupfuni-Shanga in D.R. Congo, Gataraga in Rwanda. Small scale agriculture has increased in all the benchmarked micro-catchments at the expense of other land-uses/covers. In the settlement areas land-use/cover distribution along the landscape varied across sites and countries; the major one being eucalyptus woodlots, wetland, and perennials and annuals crops in Bufundi; annuals and perennials crops in Mupfuni-Shanga; and annuals crops in Gataraga. Perennial crops tended to occur at the footslope and valley bottoms, while the annuals occurred at the upper backslopes and summits. Available P and K were relatively higher and C/N ratio (7.28 was the lowest in Mupfuni Shanga. Annual crops had the lowest available P and N across site (P<0.05. The key nutrients N, P and K were below the critical values for plant growth for Bufundi.

  12. LakeMIP Kivu: evaluating the representation of a large, deep tropical lake by a set of one-dimensional lake models

    Directory of Open Access Journals (Sweden)

    WIM Thiery

    2014-02-01

    Full Text Available The African great lakes are of utmost importance for the local economy (fishing, as well as being essential to the survival of the local people. During the past decades, these lakes experienced fast changes in ecosystem structure and functioning, and their future evolution is a major concern. In this study, for the first time a set of one-dimensional lake models are evaluated for Lake Kivu (2.28°S; 28.98°E, East Africa. The unique limnology of this meromictic lake, with the importance of salinity and subsurface springs in a tropical high-altitude climate, presents a worthy challenge to the seven models involved in the Lake Model Intercomparison Project (LakeMIP. Meteorological observations from two automatic weather stations are used to drive the models, whereas a unique dataset, containing over 150 temperature profiles recorded since 2002, is used to assess the model's performance. Simulations are performed over the freshwater layer only (60 m and over the average lake depth (240 m, since salinity increases with depth below 60 m in Lake Kivu and some lake models do not account for the influence of salinity upon lake stratification. All models are able to reproduce the mixing seasonality in Lake Kivu, as well as the magnitude and seasonal cycle of the lake enthalpy change. Differences between the models can be ascribed to variations in the treatment of the radiative forcing and the computation of the turbulent heat fluxes. Fluctuations in wind velocity and solar radiation explain inter-annual variability of observed water column temperatures. The good agreement between the deep simulations and the observed meromictic stratification also shows that a subset of models is able to account for the salinity- and geothermal-induced effects upon deep-water stratification. Finally, based on the strengths and weaknesses discerned in this study, an informed choice of a one-dimensional lake model for a given research purpose becomes possible.

  13. Geohydrology and evapotranspiration at Franklin Lake Playa, Inyo County, California

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1990-12-01

    Franklin Lake playa is one of the principal discharge areas of the Furnace Creek Ranch-Alkali Flat ground-water-flow system in southern Nevada and adjacent California. Yucca Mountain, Nevada, located within this flow system, is being evaluated by the US Department of Energy to determine its suitability as a potential site for a high-level nuclear-waste repository. To assist the US Department of Energy with its evaluation of the Yucca Mountain site, the US Geological Survey developed a parameter-estimation model of the Furnace Creek Ranch-Alkali Flat ground-water-flow system. Results from sensitivity analyses made using the parameter-estimation model indicated that simulated rates of evapotranspiration at Franklin Lake playa had the largest effect on the calculation of transmissivity values at Yucca Mountain of all the model-boundary conditions and, therefore, that evapotranspiration required careful definition. 72 refs., 59 figs., 26 tab.

  14. Geohydrology and evapotranspiration at Franklin Lake Playa, Inyo County, California

    International Nuclear Information System (INIS)

    1990-01-01

    Franklin Lake playa is one of the principal discharge areas of the Furnace Creek Ranch-Alkali Flat ground-water-flow system in southern Nevada and adjacent California. Yucca Mountain, Nevada, located within this flow system, is being evaluated by the US Department of Energy to determine its suitability as a potential site for a high-level nuclear-waste repository. To assist the US Department of Energy with its evaluation of the Yucca Mountain site, the US Geological Survey developed a parameter-estimation model of the Furnace Creek Ranch-Alkali Flat ground-water-flow system. Results from sensitivity analyses made using the parameter-estimation model indicated that simulated rates of evapotranspiration at Franklin Lake playa had the largest effect on the calculation of transmissivity values at Yucca Mountain of all the model-boundary conditions and, therefore, that evapotranspiration required careful definition. 72 refs., 59 figs., 26 tab

  15. Estimation of unregulated monthly, annual, and peak streamflows in Forest City Stream and lake levels in East Grand Lake, United States-Canada border between Maine and New Brunswick

    Science.gov (United States)

    Lombard, Pamela J.

    2018-04-30

    The U.S. Geological Survey, in cooperation with the International Joint Commission, compiled historical data on regulated streamflows and lake levels and estimated unregulated streamflows and lake levels on Forest City Stream at Forest City, Maine, and East Grand Lake on the United States-Canada border between Maine and New Brunswick to study the effects on streamflows and lake levels if two or all three dam gates are left open. Historical regulated monthly mean streamflows in Forest City Stream at the outlet of East Grand Lake (referred to as Grand Lake by Environment Canada) fluctuated between 114 cubic feet per second (ft3 /s) (3.23 cubic meters per second [m3 /s]) in November and 318 ft3 /s (9.01 m3 /s) in September from 1975 to 2015 according to Environment Canada streamgaging data. Unregulated monthly mean streamflows at this location estimated from regression equations for unregulated sites range from 59.2 ft3 /s (1.68 m3 /s) in September to 653 ft3 /s (18.5 m3 /s) in April. Historical lake levels in East Grand Lake fluctuated between 431.3 feet (ft) (131.5 meters [m]) in October and 434.0 ft (132.3 m) in May from 1969 to 2016 according to Environment Canada lake level data for East Grand Lake. Average monthly lake levels modeled by using the estimated hydrology for unregulated flows, and an outflow rating built from a hydraulic model with all gates at the dam open, range from 427.7 ft (130.4 m) in September to 431.1 ft (131.4 m) in April. Average monthly lake levels would likely be from 1.8 to 5.4 ft (0.55 to 1.6 m) lower with the gates at the dam opened than they have been historically. The greatest lake level changes would be from June through September.

  16. 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.

  17. Mercury in fish from the Pinchi Lake Region, British Columbia, Canada

    International Nuclear Information System (INIS)

    Weech, S.A.; Scheuhammer, A.M.; Elliott, J.E.; Cheng, K.M.

    2004-01-01

    Water, surface sediments, and <40 cm rainbow trout (Oncorhynchus mykiss) and northern pikeminnow (Ptychocheilus oregonensis) were collected from Pinchi Lake, British Columbia, and from several nearby reference lakes. Hg concentrations in sediment samples from Pinchi L. were highly elevated compared to sediments from reference lakes, especially in sites adjacent to and downstream of a former Hg mine. In both fish species examined, Hg concentration was positively related to age and/or fork length. In northern pikeminnow, Hg concentrations were also positively related to trophic level (δN). Hg concentrations in both fish species were highest in Pinchi L., and were higher in pikeminnow than in rainbow trout of similar size. Average Hg concentrations in small rainbow trout from all lakes, including Pinchi L., were lower than dietary levels reported to cause reproductive impairment in common loons (Gavia immer); however, Hg levels in small pikeminnow from Pinchi L. were sufficiently high to be of concern. The risk for Hg toxicity in the study area is greatest for animals that consume larger piscivorous fish such as larger northern pikeminnow or lake trout, which are known from previous studies to contain higher Hg concentrations

  18. Remedial action plan and site conceptual design for stabilization of the inactive uranium mill tailings site at Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    1991-11-01

    This volume deals with the main construction subcontract for the uranium mill tailings remedial action of Ambrosia Lake, New Mexico. Contents of subcontract documents AMB-4 include: bidding requirements; terms and conditions; specifications which cover general requirements and sitework; and subcontract drawings

  19. Results of submerged sediment core sampling and analysis on Par Pond, Pond C, and L Lake: July 1995

    International Nuclear Information System (INIS)

    Koch, J.W. II; Martin, F.D.; Friday, G.P.

    1996-06-01