WorldWideScience

Sample records for assessment lake ontario

  1. Bathymetry of Lake Ontario

    Data.gov (United States)

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

  2. Spatial extent and dissipation of the deep chlorophyll layer in Lake Ontario during the Lake Ontario lower foodweb assessment, 2003 and 2008

    Science.gov (United States)

    Watkins, J. M.; Weidel, Brian M.; Rudstam, L. G.; Holek, K. T.

    2014-01-01

    Increasing water clarity in Lake Ontario has led to a vertical redistribution of phytoplankton and an increased importance of the deep chlorophyll layer in overall primary productivity. We used in situ fluorometer profiles collected in lakewide surveys of Lake Ontario in 2008 to assess the spatial extent and intensity of the deep chlorophyll layer. In situ fluorometer data were corrected with extracted chlorophyll data using paired samples from Lake Ontario collected in August 2008. The deep chlorophyll layer was present offshore during the stratified conditions of late July 2008 with maximum values from 4–20 μg l−1 corrected chlorophyll a at 10 to 17 m depth within the metalimnion. Deep chlorophyll layer was closely associated with the base of the thermocline and a subsurface maximum of dissolved oxygen, indicating the feature's importance as a growth and productivity maximum. Crucial to the deep chlorophyll layer formation, the photic zone extended deeper than the surface mixed layer in mid-summer. The layer extended through most of the offshore in July 2008, but was not present in the easternmost transect that had a deeper surface mixed layer. By early September 2008, the lakewide deep chlorophyll layer had dissipated. A similar formation and dissipation was observed in the lakewide survey of Lake Ontario in 2003.

  3. Lake Ontario: Nearshore Variability

    Science.gov (United States)

    We conducted a high-resolution survey with towed electronic instrumentation along the Lake Ontario nearshore (720 km) at a 20 meter contour. The survey was conducted September 6-10, 2008 with a shorter 300 km survey conducted August 14-15 for comparing of temporal variability. ...

  4. Origins of rainbow smelt in Lake Ontario

    Science.gov (United States)

    Bergstedt, Roger A.

    1983-01-01

    The first rainbow smelt (Osmerus mordax) to enter Lake Ontario were probably migrants from an anadromous strain introduced into New York's Finger Lakes. Since the upper Great Lakes were originally stocked with a landlocked strain from Green Lake, Maine, subsequent migration to Lake Ontario from Lake Erie makes Lake Ontario unique among the Great Lakes in probably having received introductions from two distinct populations.

  5. The Status of Benthos in Lake Ontario

    Science.gov (United States)

    The benthic community of Lake Ontario was dominated by an amphipod (Diporeia spp.) prior to the 1990’s. Two dreissenid mussel species D. polymorpha (zebra) and D. bugensis (quagga) were introduced in 1989 and 1991 via ballast water exchange. D. bugensis was observed as deep as 85...

  6. Egg thiamine status of Lake Ontario salmonines 1995-2004 with emphasis on lake trout

    Science.gov (United States)

    Fitzsimons, J.D.; Williston, B.; Williston, G.; Brown, L.; El-Shaarawi, A.; Vandenbyllaardt, L.; Honeyfeld, D.; Tillitt, D.; Wolgamood, M.; Brown, S.B.

    2007-01-01

    Alewives (Alosa pseudoharengus), the major prey fish for Lake Ontario, contain thiaminase. They are associated with development of a thiamine deficiency in salmonines which greatly increases the potential for developing an early mortality syndrome (EMS). To assess the possible effects of thiamine deficiency on salmonine reproduction we measured egg thiamine concentrations for five species of Lake Ontario salmonines. From this we estimated the proportion of families susceptible to EMS based on whether they were below the ED20, the egg thiamine concentration associated with 20% mortality due to EMS. The ED20s were 1.52, 2.63, and 2.99 nmol/g egg for Chinook salmon (Oncorhynchus tshawytscha), lake trout (Salvelinus namaycush), and coho salmon (Oncorhynchus kisutch), respectively. Based on the proportion of fish having egg thiamine concentrations falling below the ED20, the risk of developing EMS in Lake Ontario was highest for lake trout, followed by coho (O. kisutch), and Chinook salmon, with the least risk for rainbow trout (O. mykiss). For lake trout from western Lake Ontario, mean egg thiamine concentration showed significant annual variability during 1994 to 2003, when the proportion of lake trout at risk of developing EMS based on ED20 ranged between 77 and 100%. Variation in the annual mean egg thiamine concentration for western Lake Ontario lake trout was positively related (p < 0.001, r2 = 0.94) with indices of annual adult alewife biomass. While suggesting the possible involvement of density-dependent changes in alewives, the changes are small relative to egg thiamine concentrations when alewife are not part of the diet and are of insufficient magnitude to allow for natural reproduction by lake trout.

  7. Modeling wetland plant community response to assess water-level regulation scenarios in the Lake Ontario-St. Lawrence River basin

    Science.gov (United States)

    Hudon, Christiane; Wilcox, Douglas; Ingram, Joel

    2006-01-01

    The International Joint Commission has recently completed a five-year study (2000-2005) to review the operation of structures controlling the flows and levels of the Lake Ontario - St. Lawrence River system. In addition to addressing the multitude of stakeholder interests, the regulation plan review also considers environmental sustainability and integrity of wetlands and various ecosystem components. The present paper outlines the general approach, scientific methodology and applied management considerations of studies quantifying the relationships between hydrology and wetland plant assemblages (% occurrence, surface area) in Lake Ontario and the Upper and Lower St. Lawrence River. Although similar study designs were used across the study region, different methodologies were required that were specifically adapted to suit the important regional differences between the lake and river systems, range in water-level variations, and confounding factors (geomorphic types, exposure, sediment characteristics, downstream gradient of water quality, origin of water masses in the Lower River). Performance indicators (metrics), such as total area of wetland in meadow marsh vegetation type, that link wetland response to water levels will be used to assess the effects of different regulation plans under current and future (climate change) water-supply scenarios.

  8. Research needs to better understand Lake Ontario ecosystem function: A workshop summary

    Science.gov (United States)

    Stewart, Thomas J.; Rudstam, Lars G.; Watkins, James M.; Johnson, Timothy B.; Weidel, Brian C.; Koops, Marten A.

    2016-01-01

    Lake Ontario investigators discussed and interpreted published and unpublished information during two workshops to assess our current understanding of Lake Ontario ecosystem function and to identify research needs to guide future research and monitoring activities. The purpose of this commentary is to summarize key investigative themes and hypotheses that emerged from the workshops. The outcomes of the workshop discussions are organized under four themes: spatial linkages and interactions, drivers of primary production, trophic transfer, and human interactions.

  9. Assessing past and present P Retention in Sediments in Lake Ontario (Bay of Quinte) by Reaction-Transport Diagenetic Modeling

    Science.gov (United States)

    Doan, Phuong; Berry, Sandra; Markovic, Stefan; Watson, Sue; Mugalingam, Shan; Dittrich, Maria

    2016-04-01

    Phosphorus (P) is an important macronutrient that can limit aquatic primary production and the risk of harmful algal blooms. Although there is considerable evidence that P release from sediments can represent a significant source of P and burial in sediments returns P to the geological sink; these processes have been poorly characterised. In this study, we applied a non-steady state reactive transport diagenetic model to gain insights into the dynamics of phosphorus binding forms in sediments and the phosphorus cycling of the Bay of Quinte, an embayment of Lake Ontario, Canada. The three basins of the bay (Belleville, Hay Bay and Napanee) that we investigated had differences in their phosphorus binding forms and phosphorus release, reflecting the distinct spatial temporal patterns of land use and urbanization levels in the watershed. Sediment cores from the three stations were collected during summer and under ice cover in 2013-14. Oxygen, pH and redox potential were monitored by microsensors; porewater and sediment solid matter were analyzed for P content, and a sequential extraction was used to analyze P binding forms. In the reaction-transport model, total phosphorus was divided into adsorbed phosphorus, phosphorus bound with aluminium, organic phosphorus, redox sensitive and apatite phosphorus. Using the fluxes of organic and inorganic matter as dynamic boundary conditions, we simulated the depth profiles of solute and solid components. The model closely reproduced the fractionation data of phosphorus binding forms and soluble reactive phosphorus. The past and present P fluxes were calculated and estimated; they related to geochemical conditions, and P binding forms in sediments. Our results show that P release from sediments is dominated by the redox-sentive P fraction accounting for higher percentage at Napanee station. The main P binding form that can be immobilized through diagenesis is apatite P contributing highest P retention at HayBay station. The mass

  10. 2001 USACE LRE Topobathy Lidar: Lake Ontario (NY)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Office for Coastal Management received the 2001 Lake Ontario dataset with 2 separate metadata records in 2013 on a hard-drive device from the USGS Center for...

  11. Oxygen-isotope variations in post-glacial Lake Ontario

    Science.gov (United States)

    Hladyniuk, Ryan; Longstaffe, Fred J.

    2016-02-01

    The role of glacial meltwater input to the Atlantic Ocean in triggering the Younger Dryas (YD) cooling event has been the subject of controversy in recent literature. Lake Ontario is ideally situated to test for possible meltwater passage from upstream glacial lakes and the Laurentide Ice Sheet (LIS) to the Atlantic Ocean via the lower Great Lakes. Here, we use the oxygen-isotope compositions of ostracode valves and clam shells from three Lake Ontario sediment cores to identify glacial meltwater contributions to ancient Lake Ontario since the retreat of the LIS (∼16,500 cal [13,300 14C] BP). Differences in mineralogy and sediment grain size are also used to identify changes in the hydrologic regime. The average lakewater δ18O of -17.5‰ (determined from ostracode compositions) indicates a significant contribution from glacial meltwater. Upon LIS retreat from the St. Lawrence lowlands, ancient Lake Ontario (glacial Lake Iroquois) lakewater δ18O increased to -12‰ largely because of the loss of low-18O glacial meltwater input. A subsequent decrease in lakewater δ18O (from -12 to -14‰), accompanied by a median sediment grain size increase to 9 μm, indicates that post-glacial Lake Ontario received a final pulse of meltwater (∼13,000-12,500 cal [11,100-10,500 14C] BP) before the onset of hydrologic closure. This meltwater pulse, which is also recorded in a previously reported brief freshening of the neighbouring Champlain Valley (Cronin et al., 2012), may have contributed to a weakening of thermohaline circulation in the Atlantic Ocean. After 12,900 cal [11,020 14C] BP, the meltwater presence in the Ontario basin continued to inhibit entry of Champlain seawater into early Lake Ontario. Opening of the North Bay outlet diverted upper Great Lakes water from the lower Great Lakes causing a period (12,300-8300 cal [10,400-7500 14C] BP) of hydrologic closure in Lake Ontario (Anderson and Lewis, 2012). This change is demarcated by a shift to higher δ18Olakewater

  12. 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.

  13. Sea lamprey mark type, marking rate, and parasite-host relationships for lake trout and other species in Lake Ontario

    Science.gov (United States)

    Lantry, Brian F.; Adams, Jean V.; Christie, Gavin; Schaner, Teodore; Bowlby, James; Keir, Michael; Lantry, Jana; Sullivan, Paul; Bishop, Daniel; Treska, Ted; Morrison, Bruce

    2015-01-01

    We examined how attack frequency by sea lampreys on fishes in Lake Ontario varied in response to sea lamprey abundance and preferred host abundance (lake trout > 433 mm). For this analysis we used two gill net assessment surveys, one angler creel survey, three salmonid spawning run datasets, one adult sea lamprey assessment, and a bottom trawl assessment of dead lake trout. The frequency of fresh sea lamprey marks observed on lake trout from assessment surveys was strongly related to the frequency of sea lamprey attacks observed on salmon and trout from the creel survey and spawning migrations. Attack frequencies on all salmonids examined were related to the ratio between the abundances of adult sea lampreys and lake trout. Reanalysis of the susceptibility to sea lamprey attack for lake trout strains stocked into Lake Ontario reaffirmed that Lake Superior strain lake trout were among the most and Seneca Lake strain among the least susceptible and that Lewis Lake strain lake trout were even more susceptible than the Superior strain. Seasonal attack frequencies indicated that as the number of observed sea lamprey attacks decreased during June–September, the ratio of healing to fresh marks also decreased. Simulation of the ratios of healing to fresh marks indicated that increased lethality of attacks by growing sea lampreys contributed to the decline in the ratios and supported laboratory studies about wound healing duration.

  14. Lake Ontario: Nearshore Conditions and Variability in Water Quality Parameters

    Science.gov (United States)

    Interest in recent years has increased regarding conditions in the nearshore of the Great Lakes. We conducted a high-resolution survey of the Lake Ontario nearshore along the 20 m contour using towed electronic instrumentation. The 720 km survey was conducted September 6-10, 20...

  15. Evaluation of offshore stocking of Lake Trout in Lake Ontario

    Science.gov (United States)

    Lantry, B.F.; O'Gorman, R.; Strang, T.G.; Lantry, J.R.; Connerton, M.J.; Schanger, T.

    2011-01-01

    Restoration stocking of hatchery-reared lake trout Salvelinus namaycush has occurred in Lake Ontario since 1973. In U.S. waters, fish stocked through 1990 survived well and built a large adult population. Survival of yearlings stocked from shore declined during 1990–1995, and adult numbers fell during 1998–2005. Offshore stocking of lake trout was initiated in the late 1990s in response to its successful mitigation of predation losses to double-crested cormorants Phalacrocorax auritus and the results of earlier studies that suggested it would enhance survival in some cases. The current study was designed to test the relative effectiveness of three stocking methods at a time when poststocking survival for lake trout was quite low and losses due to fish predators was a suspected factor. The stocking methods tested during 2000–2002 included May offshore, May onshore, and June onshore. Visual observations during nearshore stockings and hydroacoustic observations of offshore stockings indicated that release methods were not a direct cause of fish mortality. Experimental stockings were replicated for 3 years at one site in the southwest and for 2 years at one site in the southeast. Offshore releases used a landing craft to transport hatchery trucks from 3 to 6 km offshore out to 55–60-m-deep water. For the southwest site, offshore stocking significantly enhanced poststocking survival. Among the three methods, survival ratios were 1.74 : 1.00 : 1.02 (May offshore : May onshore : June onshore). Although not statistically significant owing to the small samples, the trends were similar for the southeast site, with survival ratios of 1.67 : 1.00 : 0.72. Consistent trends across years and sites indicated that offshore stocking of yearling lake trout during 2000–2002 provided nearly a twofold enhancement in survival; however, this increase does not appear to be great enough to achieve the 12-fold enhancement necessary to return population abundance to restoration

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

    Science.gov (United States)

    Carl, Leon M.; McGuiness, Fiona

    2006-01-01

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

  17. 77 FR 39411 - Safety Zone; Village of Sackets Harbor, Lake Ontario, Sackets Harbor, NY

    Science.gov (United States)

    2012-07-03

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Village of Sackets Harbor, Lake Ontario... establishing a temporary safety zone on Lake Ontario, Sackets Harbor, NY. This zone is intended to restrict vessels from a portion of Lake Ontario during the Village of Sackets Harbor Fireworks display....

  18. Early observations on an emerging Great Lakes invader Hemimysis anomala in Lake Ontario

    Science.gov (United States)

    Walsh, Maureen G.; Lantry, Brian F.; Boscarino, Brent; Bowen, Kelly; Gerlofsma, Jocelyn; Schaner, Ted; Back, Richard; Questel, Jennifer; Smythe, A. Garry; Cap, Roberta; Goehle, Michael; Young, Bryan; Chalupnicki, Marc A.; Johnson, James H.; McKenna, James E.

    2010-01-01

    Hemimysis anomala, a Ponto-Caspian littoral mysid, is an emerging Great Lakes invader that was discovered in Lakes Michigan and Ontario in 2006. Similar to the native mysid Mysis diluviana, Hemimysis exhibits a diel vertical migration pattern but generally inhabits shallower and warmer waters than M. diluviana. Because basic information on the distribution, habitat use, and biology of Hemimysis in the Great Lakes is scarce, the potential for food web disruption by Hemimysis cannot easily be predicted. Preliminary observations indicate widespread invasion of Hemimysis in Lake Ontario. In this study, we confirm the presence of Hemimysis at sites spanning the northern and southern shores of Lake Ontario and the presence of the individuals during winter months. In one horizontal tow in November 2007, over 26,000 individuals were collected with a length range of 4.4 to 9.0. mm and an average caloric density of 611. cal/g wet weight. The most effective methods for sampling Hemimysis were horizontal tows with either a zooplankton net in the water column or a benthic sled near the lake bottom. Although more quantitative data on the life history and distribution of this species is necessary, our preliminary observations support the prediction that the potential for Hemimysis to impact the nearshore food web in Lake Ontario appears high.

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

    OpenAIRE

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

    2006-01-01

    Two sediment cores collected from Lake Ontario and Lake Erie were sectioned, dated, and analyzed for five polycyclic musk fragrances and two nitro musk fragrances. The polycyclic musk fragrances were HHCB (Galaxolide), AHTN (Tonalide), ATII (Traseolide), ADBI (Celestolide), and AHMI (Phantolide). The nitro musk fragrances were musk ketone and musk xylene. Chemical analysis was performed by gas chromatography/mass spectrometry (GC/MS) and results from Lake Erie were confirmed using gas chromat...

  20. Sea lamprey mark type, wounding rate, and parasite-host preference and abundance relationships for lake trout and other species in Lake Ontario

    Science.gov (United States)

    Lantry, Brian F.; Adams, Jean; Christie, Gavin; Schaner, Teodore; Bowlby, James; Keir, Michael; Lantry, Jana; Sullivan, Paul; Bishop, Daniel; Treska, Ted; Morrison, Bruce

    2015-01-01

    We examined how attack frequency by sea lampreys on fishes in Lake Ontario varied in response to sea lamprey abundance and preferred host abundance (lake trout > 433 mm). For this analysis we used two gill net assessment surveys, one angler creel survey, three salmonid spawning run datasets, one adult sea lamprey assessment, and a bottom trawl assessment of dead lake trout. The frequency of fresh sea lamprey marks observed on lake trout from assessment surveys was strongly related to the frequency of sea lamprey attacks observed on salmon and trout from the creel survey and spawning migrations. Attack frequencies on all salmonids examined were related to the ratio between the abundances of adult sea lampreys and lake trout. Reanalysis of the susceptibility to sea lamprey attack for lake trout strains stocked into Lake Ontario reaffirmed that Lake Superior strain lake trout were among the most and Seneca Lake strain among the least susceptible and that Lewis Lake strain lake trout were even more susceptible than the Superior strain. Seasonal attack frequencies indicated that as the number of observed sea lamprey attacks decreased during June–September, the ratio of healing to fresh marks also decreased. Simulation of the ratios of healing to fresh marks indicated that increased lethality of attacks by growing sea lampreys contributed to the decline in the ratios and supported laboratory studies about wound healing duration.

  1. 77 FR 30451 - Safety Zone; Olcott Fireworks, Lake Ontario, Olcott, NY

    Science.gov (United States)

    2012-05-23

    ... Federal Register (73 FR 3316). Public Meeting We do not now plan to hold a public meeting. But you may... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Olcott Fireworks, Lake Ontario, Olcott, NY... establish a temporary safety zone on Lake Ontario, Olcott, NY. This proposed rule is intended to...

  2. 77 FR 38492 - Safety Zone; Olcott Fireworks, Lake Ontario, Olcott, NY

    Science.gov (United States)

    2012-06-28

    ... Fireworks, Lake Ontario, Olcott, NY in the Federal Register (77 FR 30451). We received no letters commenting... Security FR Federal Register NPRM Notice of Proposed Rulemaking A. Regulatory History and Information On... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Olcott Fireworks, Lake Ontario, Olcott,...

  3. Estimates of lake trout (Salvelinus namaycush) diet in Lake Ontario using two and three isotope mixing models

    Science.gov (United States)

    Colborne, Scott F.; Rush, Scott A.; Paterson, Gordon; Johnson, Timothy B.; Lantry, Brian F.; Fisk, Aaron T.

    2016-01-01

    Recent development of multi-dimensional stable isotope models for estimating both foraging patterns and niches have presented the analytical tools to further assess the food webs of freshwater populations. One approach to refine predictions from these analyses is to include a third isotope to the more common two-isotope carbon and nitrogen mixing models to increase the power to resolve different prey sources. We compared predictions made with two-isotope carbon and nitrogen mixing models and three-isotope models that also included sulphur (δ34S) for the diets of Lake Ontario lake trout (Salvelinus namaycush). We determined the isotopic compositions of lake trout and potential prey fishes sampled from Lake Ontario and then used quantitative estimates of resource use generated by two- and three-isotope Bayesian mixing models (SIAR) to infer feeding patterns of lake trout. Both two- and three-isotope models indicated that alewife (Alosa pseudoharengus) and round goby (Neogobius melanostomus) were the primary prey items, but the three-isotope models were more consistent with recent measures of prey fish abundances and lake trout diets. The lake trout sampled directly from the hatcheries had isotopic compositions derived from the hatchery food which were distinctively different from those derived from the natural prey sources. Those hatchery signals were retained for months after release, raising the possibility to distinguish hatchery-reared yearlings and similarly sized naturally reproduced lake trout based on isotopic compositions. Addition of a third-isotope resulted in mixing model results that confirmed round goby have become an important component of lake trout diet and may be overtaking alewife as a prey resource.

  4. 78 FR 40260 - International Joint Commission: Public Comment on a Proposal for Lake Ontario and St. Lawrence...

    Science.gov (United States)

    2013-07-03

    ... International Joint Commission: Public Comment on a Proposal for Lake Ontario and St. Lawrence River Regulation... the water levels and flows in Lake Ontario and the St. Lawrence River that will continue to contribute... health of Lake Ontario and the upper St. Lawrence River. Since 1960, the IJC has managed the flow...

  5. Hypothesis carbon flow through the deepwater Lake Ontario foodweb

    International Nuclear Information System (INIS)

    Several accounts in recent years have attempted to conceptualize foodwebs in valuable fishery systems, producing useful heuristic tools to help shape research and management policy. Here a mass balance conceptual model of the Lake Ontario deepwater foodweb is developed to evaluate energy pathways and determine available nutrition for predatory salmonines. A number of different trophic links were defined from phytoplankton, through the various forage species, to the tertiary consumers. Phytoplankton photosynthesis resulted in 178 g C/m/sup 2//yr production at the base of the foodweb. Approximately 60% of primary production was counted as required support for pelagic zooplankton and benthos. Dominant forage fish (alewife, smelt and sculpin) annually appeared to consume all smaller zooplankton carbon production, 93% of mysid production, 66% of most benthic community production, and, more specifically, 94% of amphipod carbon production. The model indicated that approximately 1.22 g C/m/sup 2//yr was available for support of top level predators. Based upon historic fishery records and stocking rates, these predators required approximately half of the annual carbon available as nutritional support. Impacts of trophic rearrangements in the Lake Ontario foodweb are discussed based upon model results

  6. A synthesis of ecological and fish-community changes in Lake Ontario, 1970-2000

    Science.gov (United States)

    Mills, E.L.; Casselman, J.M.; Dermott, R.; Fitzsimons, J.D.; Gal, G.; Holeck, K. T.; Hoyle, J.A.; Johannsson, O.E.; Lantry, B.F.; Makarewicz, J.C.; Millard, E.S.; Munawar, I.F.; Munawar, M.; O'Gorman, R.; Owens, R.W.; Rudstam, L. G.; Schaner, T.; Stewart, T.J.

    2005-01-01

    We assessed stressors associated with ecological and fishcommunity changes in Lake Ontario since 1970, when the first symposium on Salmonid Communities in Oligotrophic Lakes (SCOL I) was held (J. Fish. Res. Board Can. 29: 613-616). Phosphorus controls implemented in the early 1970s were undeniably successful; lower food-web studies showed declines in algal abundance and epilimnetic zooplankton production and a shift in pelagic primary productivity toward smaller organisms. Stressors on the fish community prior to 1970 such as exploitation, sea lamprey (Petromyzon marinus) predation, and effects of nuisance populations of alewife (Alosa pseudoharengus) were largely ameliorated by the 1990s. The alewife became a pivotal species supporting a multi-million-dollar salmonid sport fishery, but alewife-induced thiamine deficiency continued to hamper restoration and sustainability of native lake trout (Salvelinus namaycush). Expanding salmonine populations dependent on alewife raised concerns about predator demand and prey supply, leading to reductions in salmonine stocking in the early 1990s. Relaxation of the predation impact by alewives and their shift to deeper water allowed recovery of native fishes such as threespine stickleback (Gasterosteus aculeatus) and emerald shiner (Notropis atherinoides). The return of the Lake Ontario ecosystem to historical conditions has been impeded by unplanned introductions. Establishment of Dreissena spp. led to increased water clarity and increased vectoring of lower trophic-level production to benthic habitats and contributed to the collapse of Diporeia spp. populations, behavioral modifications of key fish species, and the decline of native lake whitefish (Coregonus clupeaformis). Despite reduced productivity, exotic-species introductions, and changes in the fish community, offshore Mysis relicta populations remained relatively stable. The effects of climate and climate change on the population abundance and dynamics of Lake Ontario

  7. Aquatic dispersion modelling of a tritium plume in Lake Ontario

    International Nuclear Information System (INIS)

    Approximately 2900 kg of tritiated water, containing 2.3E+15 Bq of tritium, were released to Lake Ontario via the cooling water discharge when a leak developed in a moderator heat exchanger in Unit 1 at the Pickering Nuclear Generating Station (PNGS) on 1992 August 2. The release provided the opportunity to study the dispersion of a tritium plume in the coastal zone of Lake Ontario. Current direction over the two-week period following the release was predominantly parallel to the shore, and elevated tritium concentrations were observed up to 20 km east and 85 km west of the PNGS. Predictions of the tritium plume movement were made using current velocity measurements taken at 8-m depth, 2.5 km offshore from Darlington and using a empirical relationship where alongshore current speed is assumed to be proportional to the alongshore component of the wind speed. The tritium migration was best described using current velocity measurements. The tritium plume dispersion is modelled using the one-dimensional advection-dispersion equation. Transport parameters are the alongshore current speed and longitudinal dispersion coefficient. Longitudinal dispersion coefficients, estimated by fitting the solution of the advection-dispersion equation to measured concentration distance profiles ranged from 3.75 to 10.57 m2s-1. Simulations using the fitted values of the dispersion coefficient were able to describe maximum tritium concentrations measured at water supply plants located within 25 km of Pickering to within a factor of 3. The dispersion coefficient is a function of spatial and temporal variability in current velocity and the fitted dispersion coefficients estimated here may not be suitable for predicting tritium plume dispersion under different current conditions. The sensitivity of the dispersion coefficient to variability in current conditions should be evaluated in further field experiments. (author). 13 refs., 7 tabs., 12 figs

  8. Hydrography - Lakes Assessments - Attaining

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This layer shows only attaining lakes of the Integrated List. The Lakes Integrated List represents lake assessments in an integrated format for the Clean Water Act...

  9. Paternal Lake Ontario fish consumption and risk of conception delay, New York state angler cohort

    Energy Technology Data Exchange (ETDEWEB)

    Buck, G.M.; Mendola, P.; Vena, J.E.; Kostyniak, P.; Greizerstein, H.; Olson, J.; Stephen, F.D. [State Univ. of New York, Buffalo, NY (United States). Dept. of Social and Preventive Medicine; Sever, L.E. [Battelle, Seattle, WA (United States). Centers for Public Health and Evaluation

    1999-02-01

    The aquatic ecosystems of the Great Lakes are contaminated with a variety of compounds, some of which are considered reproductive toxicants. Few studies of paternal fish consumption and reproductive endpoints have been undertaken and serve as the impetus for study. Standardized telephone interviews were conducted with 2,445 female members of the New York State Angler Cohort (82% response) to update reproductive profiles and to ascertain specific information on time-to-pregnancy (TTP). The study sample includes women with a known TTP and paternal fish consumption data (n = 785). Conception delay was defined as more than 12 cycles of unprotected intercourse to achieve pregnancy. Paternal fish consumption was assessed by three measures: frequency of Lake Ontario sport fish meals in 1991, numbers of years eating fish, and estimated PCB exposure from fish consumption. Adjusted ORs for number of fish meals, based on logistic regression, ranged from 0.69 to 0.80; from 0.61 to .82 for number of years eating fish; and from 0.44 to 1.14 for quartiles of estimated PCB exposure from fish consumption. All confidence intervals included one. These findings suggest that, based on paternal self-reports, Lake Ontario fish consumption does not increase the risk of conception delay.

  10. 46 CFR 401.405 - Basic rates and charges on the St. Lawrence River and Lake Ontario.

    Science.gov (United States)

    2010-10-01

    ... affecting § 401.405, see the List of CFR Sections Affected, which appears in the Finding Aids section of the... Lake Ontario. 401.405 Section 401.405 Shipping COAST GUARD (GREAT LAKES PILOTAGE), DEPARTMENT OF... § 401.405 Basic rates and charges on the St. Lawrence River and Lake Ontario. Except as provided...

  11. The impact of acid deposition and forest harvesting on lakes and their forested catchments in south central Ontario: a critical loads approach

    OpenAIRE

    Watmough, S. A.; Dillon, P. J.

    2002-01-01

    International audience The impact of acid deposition and tree harvesting on three lakes and their representative sub-catchments in the Muskoka-Haliburton region of south-central Ontario was assessed using a critical loads approach. As nitrogen dynamics in forest soils are complex and poorly understood, for simplicity and to allow comparison among lakes and their catchments, CLs (A) for both lakes and forest soils were calculated assuming that nitrate leaching from catchments will not chang...

  12. Maternal characteristics versus egg size and energy density: do stocked lake trout in Lake Ontario experience premature reproductive senescence?

    Science.gov (United States)

    Lantry, B.F.; O'Gorman, R.; Machut, L.S.

    2008-01-01

    Observations from September 1994 and 1997 collections of hatchery-origin, mature female lake trout (Salvelinus namaycush) from Lake Ontario indicated that egg mass decreased with age, fueling the notion that stocked fish experienced premature reproductive senescence. Supplemental collections during September 2002 and November 2002-2004 were combined with the 1994 and 1997 samples to examine whether sample date or maternal age, body mass, condition (K), egg count, or strain were related to egg mass or energy content (percentage dry mass [%DM]). Body mass was correlated with egg mass for age ≥ 8 lake trout sampled in September, and egg count was correlated with egg mass for September age-6 lake trout only. Within each month, egg mass was not related to K or egg %DM, however, egg %DM was 1.52% greater (P ≤ 0.0247) in November than in September which is equivalent to a 110 cal/g difference. Samples were grouped for the three most abundant strains (Seneca, Superior, and Ontario) after finding no strain or year effects from our 1994 and 1997 samples and based on life history data from the literature and our assessment sampling. Further analysis indicated that September egg masses were greater for fish ages ≤ 6 than for fish ages ≥ 8. The age effect disappeared in November when mean egg mass across all ages (0.078 g) was greater than September means (P < 0.0005) for ages -5 (0.054 g), -6 (0.057 g) and ≥ 8 (0.041 g). Our results indicate that the decrease in egg mass with female age in September was not due to senescence, but to oogenesis being closer to completion in young age-5 and -6 fish than in older individuals.

  13. Analysis of three cisco forms (Coregonus, Salmonidae) from Lake Saganaga and adjacent lakes near the Minnesota/Ontario border

    NARCIS (Netherlands)

    Etnier, DA; Skelton, CE

    2003-01-01

    Based on examination of 655 ciscoes from Lake Saganaga, a Minnesota/Ontario border lake, three forms, about 90% separable on gill raker counts, are present. Form L, with the lowest gill raker counts (26-40, mean = 31.9, n = 96) is tentatively identified as Coregonus zenithicus. Form M, with intermed

  14. SF6 ventilation study at Agnew Lake Mines, Ontario

    International Nuclear Information System (INIS)

    In September 1978, James F. MacLaren Limited was awarded a contract by the Canada Centre for Mineral and Energy Technology (CANMET) to undertake a ventilation study at an underground uranium mine using sulphur hexafluoride (SF6) as a tracer gas. The mine selected for the study was that of Agnew Lake Mines Limited in Northern Ontario. This is a relatively new mine with the combined mine/mill facilities first operational in mid-1977. Uranium is recovered from broken ore by in-situ leaching. The ventilation study was divided into two phases. A laboratory study was undertaken to develop a practical sampling technique, provide an evaluation of the logistics of long range sample transport and develop a laboratory analytical technique. Field programmes demonstrated the SF6 tracer gas technique for mine ventilation trouble-shooting with the intent of providing information which will lead to more efficient use of existing mine ventilation capacity. This report outlines the findings of the laboratory study and the two field programmes

  15. National Lakes Assessment Data

    Data.gov (United States)

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

  16. Hidden plastics of Lake Ontario, Canada and their potential preservation in the sediment record

    International Nuclear Information System (INIS)

    Microplastics are a source of environmental pollution resulting from degradation of plastic products and spillage of resin pellets. We report the amounts of microplastics from various sites of Lake Ontario and evaluate their potential for preservation in the sediment record. A total of 4635 pellets were sampled from the Humber Bay shoreline on three sampling dates. Pellet colours were similar to those from the Humber River bank, suggesting that the river is a pathway for plastics transport into Lake Ontario. Once in the lake, high density microplastics, including mineral-polyethylene and mineral-polypropylene mixtures, sink to the bottom. The minerals may be fillers that were combined with plastics during production, or may have adsorbed to the surfaces of the polymers in the water column or on the lake bottom. Based on sediment depths and accumulation rates, microplastics have accumulated in the offshore region for less than 38 years. Their burial increases the chance of microplastics preservation. Shoreline pellets may not be preserved because they are mingled with organic debris that is reworked during storm events. - Highlights: • We determine the amount of microplastics in Lake Ontario shore and bottom sediments. • Pellet preservation in shoreline sediment is unlikely. • Microplastics have been accumulating in bottom sediments over <38 years. • Buried plastics in lake bottom sediment have a high potential for preservation. - Microplastics were identified in bottom sediments of Lake Ontario. Their burial could result in microplastics preservation in the future rock record

  17. Lake sturgeon population attributes and reproductive structure in the Namakan Reservoir, Minnesota and Ontario

    Science.gov (United States)

    Shaw, S. L.; Chipps, Steven R.; Windels, S. K.; Webb, M.A.H.; McLeod, D. T.; Willis, D.W.

    2012-01-01

    Quantified were the age, growth, mortality and reproductive structure of lake sturgeon (Acipenser fulvescens) collected in the US and Canadian waters of the Namakan Reservoir. The hypotheses were tested that (i) age and growth of lake sturgeon in the Namakan Reservoir would differ by sex and reproductive stage of maturity, and (ii) that the relative strength of year-classes of lake sturgeon in the reservoir would be affected by environmental variables. To quantify age, growth and mortality of the population, existing data was used from a multi-agency database containing information on all lake sturgeon sampled in the reservoir from 2004 to 2009. Lake sturgeon were sampled in the Minnesota and Ontario waters of the Namakan Reservoir using multi-filament gillnets 1.8 m high and 30–100 m long and varying in mesh size from 178 to 356 mm stretch. Reproductive structure of the lake sturgeon was assessed only during spring 2008 and 2009 using plasma testosterone and estradiol-17β concentrations. Ages of lake sturgeon >75 cm ranged from 9 to 86 years (n = 533, mean = 36 years). A catch-curve analysis using the 1981–1953 year classes estimated total annual mortality of adults to be 4.8% and annual survival as 95.2%. Using logistic regression analysis, it was found that total annual precipitation was positively associated with lake sturgeon year-class strength in the Namakan Reservoir. A 10 cm increase in total annual precipitation was associated with at least a 39% increase in the odds of occurrence of a strong year class of lake sturgeon in the reservoir. Plasma steroid analysis revealed a sex ratio of 2.4 females: 1 male and, on average, 10% of female and 30% of male lake sturgeon were reproductively mature each year (i.e. potential spawners). Moreover, there was evidence based on re-captured male fish of both periodic and annual spawning, as well as the ability of males to rapidly undergo gonadal maturation prior to spawning. Knowledge of lake sturgeon

  18. Utilization of bathymetry data to examine lead sediment contamination distributions in Lake Ontario

    Directory of Open Access Journals (Sweden)

    Chris H. Marvin

    2016-06-01

    Full Text Available Bathymetry data offer interesting opportunities for the analysis of contaminant distribution patterns. This research utilized lead surficial sediment sample data from Lake Ontario that were collected by the Canada Centre for Inland Waters in 1968 and 1998. Traditionally, two-dimensional analyses such as dot maps or proportional circle representation have been utilized to examine pollutant levels. Generating area estimates allows for expanded spatial analysis of contaminant distribution patterns. Lake-wide surfaces were derived using the ordinary kriging technique. These were then layered on bathymetry data to examine three-dimensional relationships between observed pollution patterns and lake-bottom features. Spatial variability was observed in both the 1968 and 1998 datasets. Contamination levels in 1998 dropped substantially, especially in areas that were previously the most heavily polluted and above the Probable Effect Level (4660.23 km2 or 26.72% of the common analysis area lake-bottom in 1998 versus 6189.07 km2 or 62.00% in 1968. Conversely, areas below the Threshold Effect Level increased from 922.09 km2 (5.29% in 1968 to 3484.22 km2 (19.98% in 1998. In both years, shallow and sill/ridge areas tended to have lower levels of contamination than deeper lake basins or contaminant inflow areas. The 1968 dataset likely provides a more detailed estimation surface as there were more points available for interpolation procedures. The kriging surfaces when combined with bathymetry, sedimentology information, and knowledge of physical processes provide a comprehensive illustration of the contaminant distributions whether they are high (1968 or when loadings are significantly reduced (1998. The results have implications for future sediment assessment programs and survey design on a lake-wide basis. The bathymetry data allowed for enhanced interpretation and an improved understanding of observed lead pollution patterns.

  19. A heuristic simulation model of Lake Ontario circulation and mass balance transport

    Science.gov (United States)

    McKenna, J.E., Jr.; Chalupnicki, M.A.

    2011-01-01

    The redistribution of suspended organisms and materials by large-scale currents is part of natural ecological processes in large aquatic systems but can contribute to ecosystem disruption when exotic elements are introduced into the system. Toxic compounds and planktonic organisms spend various lengths of time in suspension before settling to the bottom or otherwise being removed. We constructed a simple physical simulation model, including the influence of major tributaries, to qualitatively examine circulation patterns in Lake Ontario. We used a simple mass balance approach to estimate the relative water input to and export from each of 10 depth regime-specific compartments (nearshore vs. offshore) comprising Lake Ontario. Despite its simplicity, our model produced circulation patterns similar to those reported by more complex studies in the literature. A three-gyre pattern, with the classic large counterclockwise central lake circulation, and a simpler two-gyre system were both observed. These qualitative simulations indicate little offshore transport along the south shore, except near the mouths of the Niagara River and Oswego River. Complex flow structure was evident, particularly near the Niagara River mouth and in offshore waters of the eastern basin. Average Lake Ontario residence time is 8 years, but the fastest model pathway indicated potential transport of plankton through the lake in as little as 60 days. This simulation illustrates potential invasion pathways and provides rough estimates of planktonic larval dispersal or chemical transport among nearshore and offshore areas of Lake Ontario. ?? 2011 Taylor & Francis.

  20. Diet composition and feeding periodicity of wild and hatchery subyearling Chinook salmon in Lake Ontario

    Science.gov (United States)

    Johnson, J.H.

    2008-01-01

    Diel feeding periodicity, daily ration, and diet composition of wild and hatchery subyearling Chinook salmon Oncorhynchus tshawytscha were examined in Lake Ontario and the Salmon River, New York. The diet of wild riverine salmon was composed mainly of aquatic invertebrates (63.4%), mostly ephemeropterans (25.8%), chiromomids (15.8%), and trichopterans (8.3%). The diet of riverine Chinook was more closely associated with the composition of drift samples rather than bottom samples, suggesting mid-water feeding. In Lake Ontario terrestrial invertebrates were more important in the diet of hatchery Chinook (49.0%) than wild salmon (30.5%) and diet overlap between hatchery and wild salmon was low (0.46%). The diet of both hatchery and wild Chinook salmon was more closely associated with the composition of mid-water invertebrate samples rather than benthic core samples, indicating mid-water and surface feeding. Hatchery Chinook salmon consumed significantly less food (P Ontario consumed more food than wild salmon in the Salmon River. Peak feeding of wild Chinook salmon occurred between 1200-1600 hours in Lake Ontario and between 1600-2000 hours in the Salmon River; there was no discernable feeding peak for the hatchery Chinook in Lake Ontario. Hatchery Chinook salmon also had the least diverse diet over the 24-hour sample period. These results suggest that at 7 days post-stocking hatchery Chinook salmon had not yet fully adapted to their new environment.

  1. Interspecific competition in tributaries: Prospectus for restoring Atlantic salmon in Lake Ontario

    Science.gov (United States)

    Johnson, James H.; Wedge, Leslie R.

    1999-01-01

    Historically, Lake Ontario may have supported the world's largest freshwater population of Atlantic salmon (Salmo salar). However, by the late 1800's, salmon were virtually extinct in the lake due to the damming of tributaries, overharvest, deforestation, and pollution. Of these factors, the building of dams on tributaries, which precluded access by the salmon to natal spawning streams, was probably the most detrimental. Since the extirpation of Atlantic salmon in the Lake Ontario watershed over a century ago, considerable change has occurred throughout the lake and tributary ecosystem. The changes within the ecosystem that may have the most profound effect on Atlantic salmon restoration include the presence of exotic species, including other salmonines, and reduced habitat quality, especially in tributaries. These changes must be taken into account when considering Atlantic salmon restoration.

  2. Active shoreline of Ontario Lacus, Titan: A morphological study of the lake and its surroundings

    Science.gov (United States)

    Wall, S.; Hayes, A.; Bristow, C.; Lorenz, R.; Stofan, E.; Lunine, J.; Le, Gall A.; Janssen, M.; Lopes, R.; Wye, L.; Soderblom, L.; Paillou, P.; Aharonson, O.; Zebker, H.; Farr, Tom; Mitri, G.; Kirk, R.; Mitchell, Ken; Notarnicola, C.; Casarano, D.; Ventura, B.

    2010-01-01

    Of more than 400 filled lakes now identified on Titan, the first and largest reported in the southern latitudes is Ontario Lacus, which is dark in both infrared and microwave. Here we describe recent observations including synthetic aperture radar (SAR) images by Cassini's radar instrument (??= 2 cm) and show morphological evidence for active material transport and erosion. Ontario Lacus lies in a shallow depression, with greater relief on the southwestern shore and a gently sloping, possibly wave-generated beach to the northeast. The lake has a closed internal drainage system fed by Earth-like rivers, deltas and alluvial fans. Evidence for active shoreline processes, including the wave-modified lakefront and deltaic deposition, indicates that Ontario is a dynamic feature undergoing typical terrestrial forms of littoral modification. Copyright ?? 2010 by the American Geophysical Union.

  3. Comparative diets of subyearling Atlantic salmon and subyearling coho salmon in Lake Ontario tributaries

    Science.gov (United States)

    Johnson, James H.; Ringler, Neil H.

    2016-01-01

    Restoration of Atlantic salmon (Salmo salar) in Lake Ontario could potentially be negatively affected by the presence of non-native salmonids that are naturalized in the basin. Coho salmon (Oncorhynchus kisutch) have been spawning successfully in Lake Ontario tributaries for over 40 years and their juveniles will reside in streams with juvenile Atlantic salmon for one year. This study sought to examine interspecific diet associations between these species, and to compare diets to the composition of the benthos and drift in three Lake Ontario tributaries. Aquatic insects, mainly ephemeropterans and chironomids were the major prey consumed by subyearling Atlantic salmon whereas terrestrial invertebrates made up only 3.7% of the diet. Ephemeropterans and chironomids were the primary aquatic taxa consumed by subyearling coho salmon but, as a group, terrestrial invertebrates (41.8%) were the major prey. In sympatry, Atlantic salmon fed more actively from the benthos whereas the diet of coho salmon was more similar to the drift. The different feeding pattern of each species resulted in low interspecific diet similarity. There is likely little competition between these species for food in Lake Ontario tributaries as juveniles.

  4. Sources and sinks of microplastics in Canadian Lake Ontario nearshore, tributary and beach sediments.

    Science.gov (United States)

    Ballent, Anika; Corcoran, Patricia L; Madden, Odile; Helm, Paul A; Longstaffe, Fred J

    2016-09-15

    Microplastics contamination of Lake Ontario sediments is investigated with the aim of identifying distribution patterns and hotspots in nearshore, tributary and beach depositional environments. Microplastics are concentrated in nearshore sediments in the vicinity of urban and industrial regions. In Humber Bay and Toronto Harbour microplastic concentrations were consistently >500 particles per kg dry sediment. Maximum concentrations of ~28,000 particles per kg dry sediment were determined in Etobicoke Creek. The microplastic particles were primarily fibres and fragments microplastics in terms of how and where to implement preventative measures to reduce the contaminant influx. Although the impacts of microplastics contamination on ecosystem health and functioning is uncertain, understanding, monitoring and preventing further microplastics contamination in Lake Ontario and the other Great Lakes is crucial. PMID:27342902

  5. Lake acidity and the distribution and abundance of water striders (Hemiptera: Gerridae) near Sudbury, Ontario

    Energy Technology Data Exchange (ETDEWEB)

    Bendell, B.E. (Canadian Wildlife Service, Ottawa, ON (Canada))

    1988-01-01

    The presence of major water strider species was recorded in a survey of 53 lakes covering a wide range of acidity near Sudbury, Ontario. The mean pH of lakes on which Metrobates hesperius and Trepobates inermis were found was significantly higher than the mean pH lakes from which they were absent. Metrobates hesperius was never found at pH<5.1. There was no evidence that the distributions of Gerris spp. were related to lake acidity. Quantitative sampling was undertaken to examine the relationship between the abundance of Rheumatobates rileyi and lake acidity, and any concomitant relationship to fish. A highly significant positive relationship was found between densities of R. rileyi and lake pH, but no relationship was found with the presence or absence of fish. 19 refs., 2 figs.

  6. Protecting Lake Ontario - Treating Wastewater from the Remediated Low-Level Radioactive Waste Management Facility - 13227

    Energy Technology Data Exchange (ETDEWEB)

    Freihammer, Till; Chaput, Barb [AECOM, 99 Commerce Drive, Winnipeg, Manitoba, R3P 0Y7 (Canada); Vandergaast, Gary [Atomic Energy of Canada Limited, Port Hope, Ontario (Canada); Arey, Jimi [Public Works and Government Services Canada, Ontario (Canada)

    2013-07-01

    The Port Granby Project is part of the larger Port Hope Area Initiative, a community-based program for the development and implementation of a safe, local, long-term management solution for historic low level radioactive waste (LLRW) and marginally contaminated soils (MCS). The Port Granby Project involves the relocation and remediation of up to 0.45 million cubic metres of such waste from the current Port Granby Waste Management Facility located in the Municipality of Clarington, Ontario, adjacent to the shoreline of Lake Ontario. The waste material will be transferred to a new suitably engineered Long-Term Waste Management Facility (LTWMF) to be located inland approximately 700 m from the existing site. The development of the LTWMF will include construction and commissioning of a new Wastewater Treatment Plant (WWTP) designed to treat wastewater consisting of contaminated surface run off and leachate generated during the site remediation process at the Port Granby Waste Management Facility as well as long-term leachate generated at the new LTWMF. Numerous factors will influence the variable wastewater flow rates and influent loads to the new WWTP during remediation. The treatment processes will be comprised of equalization to minimize impacts from hydraulic peaks, fine screening, membrane bioreactor technology, and reverse osmosis. The residuals treatment will comprise of lime precipitation, thickening, dewatering, evaporation and drying. The distribution of the concentration of uranium and radium - 226 over the various process streams in the WWTP was estimated. This information was used to assess potential worker exposure to radioactivity in the various process areas. A mass balance approach was used to assess the distribution of uranium and radium - 226, by applying individual contaminant removal rates for each process element of the WTP, based on pilot scale results and experience-based assumptions. The mass balance calculations were repeated for various flow

  7. Radium-226 in water, sediments, and fish from lakes near the city of Elliot Lake, Ontario, Canada.

    Science.gov (United States)

    Clulow, F V; Davé, N K; Lim, T P; Avadhanula, R

    1998-01-01

    Ra-226 was measured by alpha-emission spectroscopy in water, sediments, and fish (tissues and gut contents), from five lakes in a watershed containing U mining and milling operations at Elliot Lake, Ontario, and from control lakes in an adjacent non-industrialized watershed. Ra-226 transfer parameters from lake water and sediments to fish tissues, and annual intakes by humans consuming fish, were estimated. Mean dissolved 226Ra levels ranged from approximately 76 mBq litre(-1) in water of the most affected lake, to Ra-226 levels in lake trout muscle were low and showed erratic variation among lakes whereas levels in whitefish muscle did not vary significantly among study and control sites. Lake herring (= cisco, Coregonus artedii), a planktivorous fish taken only from Quirke Lake, had mean 226Ra levels of 18 and 1.4 mBq g(-1) dry wt in bone and muscle, respectively. Gut 226Ra levels, highest in lake trout from McCabe and Quirke Lakes (126 +/- 53, 64 +/- 44 mBq g(-1) dry wt, respectively), and just detectable in McCabe and Elliot Lake whitefish (24 +/- 2, 36 +/- 14 mBq g(-1) dry wt, respectively), were below detection in lake trout and whitefish from other lakes. Concentration ratios (CRs) of 226Ra from water to muscle ranged from 8 to 14 in lake trout, 7 to 14 in whitefish, and 4 to 6 in lake herring. The water to bone CRs varied from 81 to 142, 314 to 548, and 126 to 272 in the same species. CRs were always 2 mSv year(-1)) and the public dose limit (5 mSv year(-1)).

  8. Status of important prey fishes in the U.S. waters of Lake Ontario, 2013: Introduction and methods, alewife, rainbow smelt, sculpins, and round goby

    Science.gov (United States)

    Weidel, Brian C.; Walsh, Maureen; Connerton, Michael

    2014-01-01

    Lake Ontario has a mean depth of 86 m (282 ft) and a maximum depth of 244 m (801 ft) (Herdendorf 1982). The southern, New York portion of the lake has the deepest water (Figure 1). In New York waters, about 67% of the lake is <160 m (525 ft) deep and about 82% of the lake is <180 m (591 ft) deep. The U.S. Geological Survey (USGS) and New York State Department of Environmental Conservation (NYSDEC) have cooperatively assessed Lake Ontario prey fishes each year since 1978. Bottom trawl assessments were initially focused on Alewife Alosa pseudoharengus (April), Rainbow Smelt Osmerus mordax (June), and Slimy Sculpin Cottus cognatus (October). Seasonal survey timing corresponded to the peak catches in 1972 when collections were made every month May to October (Owens et al. 2003). Twelve transects were established at approximately 25-km intervals along the U.S. shoreline (Figure 2). Alewife assessment was conducted at all transects, Rainbow Smelt assessment at all transects except Fair Haven, and six transects representing eastern, southern, and western lake areas were sampled for Slimy Sculpin (Figure 2). Changes in the Lake Ontario ecosystem (species invasion, oligotrophication, native species rebound) require ongoing evaluation of current methods which sometimes necessitate redistribution of trawl effort, or changes in sampling designs and/or gear. For instance, the spring Alewife assessment is now used also to assess invasive Round Goby Neogobius melanostomus population dynamics. Likewise, the fall benthic fish assessment (formerly sculpin assessment) now also tracks dynamics of the rebounding native Deepwater Sculpin Myoxocephalus thompsonii population, the apparent declining population of Slimy Sculpin, and fall distribution of Round Goby.

  9. Origin of drumlins on the floor of Lake Ontario and in upper New York State

    Science.gov (United States)

    Kerr, Michael; Eyles, Nick

    2007-01-01

    Upper New York State, USA contains one of the largest drumlin fields (12,000 km 2) on the North America continent consisting of some 10,000 drumlins located between Lake Ontario in the north and the Finger Lakes; drumlin-like bedforms have also recently been discovered in deep water (˜ 200 m) on the nearby floor of the Rochester Basin in Lake Ontario. The New York State drumlin field was produced under the Laurentide Ice Sheet 18,000 years ago when it extended southwards to terminate against the Allegheny Plateau. Outcrops of drumlin cores exposed by erosion along the Lake Ontario shoreline provide windows into the stratigraphy and sedimentology of the northern part of the field. Sedimentological description of 10 coastal drumlin cores, combined with quantitative morphometric analysis of 1487 drumlins, shows that they are the product of subglacial erosion of till sheets separated by glaciolacustrine deposits. A two-phase subglacial model for drumlin formation is suggested consisting of initial aggradation of extensive till deposits during ice advance followed by erosion and streamlining possibly accompanying stillstand of the ice margin and building of moraines. Systematic changes in drumlin morphometry and spacing are evident, ranging from small numbers ( 60%) closely spaced, ovoid drumlins (L/W ratios between 1 and 3). Drumlin shape appears to be systematically related to sediment thickness available for erosional streamlining; elongate spindle forms occur on the crests and lee sides of bedrock escarpments where sediment cover is thin. Larger ovoid drumlins occur in topographic depressions where sediment thickness is greater. Offshore streamlined forms on the floor of the deep water Rochester Basin in Lake Ontario have long axes at right angles to the trend of onshore drumlins. These are composed of rock (rock drumlins) and have an orientation structurally controlled by a newly identified inlier of Proterozoic Grenville Province metasediments.

  10. The impact of acid deposition and forest harvesting on lakes and their forested catchments in south central Ontario: a critical loads approach

    OpenAIRE

    Watmough, S. A.; Dillon, P. J.

    2002-01-01

    The impact of acid deposition and tree harvesting on three lakes and their representative sub-catchments in the Muskoka-Haliburton region of south-central Ontario was assessed using a critical loads approach. As nitrogen dynamics in forest soils are complex and poorly understood, for simplicity and to allow comparison among lakes and their catchments, CLs (A) for both lakes and forest soils were calculated assuming that nitrate leaching from catchments will not change over time (i.e. a best c...

  11. Hydrography - Lakes Assessments - Non Attaining

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This layer shows only non attaining lakes of the Integrated List. The Lakes Integrated List represents lake assessments in an integrated format for the Clean Water...

  12. Mortality factors in whistling swans at Lake St. Clair, Ontario

    Energy Technology Data Exchange (ETDEWEB)

    Irwin, J.C.

    1975-01-01

    Post mortem examinations of 31 whistling swans (Olor columbianus) collected from the Lake St. Clair marshes in the spring of 1972 indicated that lead toxicosis and filariasis (Sarconema eurycerca) were the main causes of mortality. 13 references, 2 tables.

  13. The Expansion of Dreissena and Long-term Shifts in Benthic Macroinvertebrate Community Structure in Lake Ontario, 1998-2008

    Science.gov (United States)

    The introduction of Dreissena to the Great lakes has profoundly impacted benthic ecosystems, resulting in the decline of native species and dramatic community restructuring. In Lake Ontario, long-term monitoring has yielded a wealth of detailed information regarding both the exp...

  14. Occurrence and food habits of the round goby in the profundal zone of southwestern Lake Ontario

    Science.gov (United States)

    Walsh, M.G.; Dittman, D.E.; O'Gorman, R.

    2007-01-01

    Little is known about the ecology of round goby (Neogobius melanostomus), an invasive benthic fish, in the profundal zone of the Great Lakes. In April 2002–2005 we caught increasing numbers of round gobies with a bottom trawl in the 45–150 m depth range of southwestern Lake Ontario. In 2005, we examined gut contents of 30 round gobies from each of three depths, 55, 95, and 130 m, and qualitatively compared gut contents with density of benthic invertebrates determined by Ponar grabs. Round goby guts contained mostly Dreissena spp. and opposum shrimp, Mysis relicta (Mysis); the frequency of occurrence of dreissenids in guts decreased with depth, whereas the frequency of occurrence of Mysis in guts increased with depth. Abundance of these invertebrates in the environment followed the same pattern, although dreissenids of optimum edible size (3–12 mm) were still abundant (1,373/m2) at 130 m, where round gobies primarily consumed Mysis, suggesting that round gobies may switch from dreissenids to more profitable prey when it is available. Other food items were ostracods and fish, with ostracods generally eaten by smaller round gobies and fish eaten by larger round gobies. Occurrence and increasing abundance of round gobies in the profundal zone and predation on Mysis by round goby could have far-reaching consequences for the Lake Ontario fish community.

  15. The Lake Ontario zooplankton community before (1987-1991) and after (2001-2005) invasion-induced ecosystem change

    Science.gov (United States)

    Stewart, T.J.; Johannsson, O.E.; Holeck, K.; Sprules, W.G.; O'Gorman, R.

    2010-01-01

    We assessed changes in Lake Ontario zooplankton biomass, production, and community composition before (1987–1991) and after (2001–2005) invasion-induced ecosystem changes. The ecosystem changes were associated with establishment of invasive dreissenid mussels and invasive predatory cladocerans (Bythotrephes and Cercopagis). Whole-lake total epilimnetic plus metalimnetic zooplankton production declined by approximately half from 42.45 (g dry wt∙m−2∙ year−1) during 1987–1991 to 21.91 (g dry wt∙m−2∙ year−1) in 2003 and averaged 21.01 (g dry wt∙m−2∙ year−1) during 2001–2005. Analysis of two independent data sets indicates that the mean biomass and biomass proportion of cyclopoid copepods declined while the same measures increased for the invasive predatory cladocerans. Changes in means and proportions of all other zooplankton groups were not consistent between the data sets. Cyclopoid copepod biomass and production declined by factors ranging from 3.6 to 5.7. Invasive predatory cladoceran biomass averaged from 5.0% to 8.0% of the total zooplankton biomass. The zooplankton community was otherwise resilient to the invasion-induced disruption as zooplankton species richness and diversity were unaffected. Zooplankton production was likely reduced by declines in primary productivity but may have declined further due to increased predation by alewives and invasive predatory cladocerans. Shifts in zooplankton community structure were consistent with increased predation pressure on cyclopoid copepods by alewives and invasive predatory cladocerans. Predicted declines in the proportion of small cladocerans were not evident. This study represents the first direct comparison of changes in Lake Ontario zooplankton production before and after the invasion-induced disruption and will be important to food web-scale investigations of invasion effects.

  16. Preliminary assessment of the current impact and potential risk of acidic deposition on walleye populations in Ontario

    Energy Technology Data Exchange (ETDEWEB)

    Wales, D.L.; Liimatainen, V.A.

    1987-01-01

    Netting survey and field bioassay data were used to determine a pH threshold for survival of walleye. Established pH thresholds were then used to assess the current impact and potential risk of acidic deposition on walleye populations in Ontario. Extinction of walleye appeared to occur in lakes with pH < 5.5. Some losses may also have occurred in lakes with pH 5.5-6.0. An estimated 0.3% (number of lakes (N)=12) of the Ontario walleye lakes currently have pH < 5.5 and have likely lost walleye populations. A further 1.5% (N=60) of the lakes have pH 5.5-6.0 and may show signs of acidification stress. An estimated 2.0% (N=79) of the province's walleye lakes have very low alkalinities (0.0-2.0 mg/l) and are classified as extremely sensitive to continued high deposition of acidic precipitation. 19 refs., 4 figs., 7 tabs.

  17. Diel diet composition and feeding activity of round goby in the nearshore region of Lake Ontario

    Science.gov (United States)

    Johnson, J.H.; McKenna, J.E., Jr.; Nack, C.C.; Chalupnicki, M.A.

    2008-01-01

    Expansion of the invasive round goby Apollonia melanostoma (=Neogobius melanostomus) throughout the Great Lakes drainage has created considerable concern among fisheries management agencies. These concerns have led to several studies on the biology and impact of the goby in the basin. However, little information exists on diel patterns in food consumption of the round goby. We examined the diets of 300 round gobies collected during crepuscular, diurnal, and nocturnal periods in Lake Ontario. There was little variation in the diel diet composition of the goby, as chironomid larvae were the major prey consumed during each period. Feeding intensity of the round goby was significantly (P<0.05) greater at night than during crepuscular or diurnal periods.

  18. Estimating mercury concentrations and fluxes in the water column and sediment of Lake Ontario with HERMES model.

    Science.gov (United States)

    Ethier, Adrienne L M; Atkinson, Joseph F; Depinto, Joseph V; Lean, David R S

    2012-02-01

    The HERMES model-predicted Hg concentrations and fluxes in Lake Ontario were based on twelve lake and drainage basin variables (i.e., water temperature, precipitation rate, air Hg, surface area, mean depth, water volume, water inflow rate, inflow water Hg, inflow and lake suspended particulate matter, air-water and water-air mass transfer coefficients, and sedimentation rate). The HERMES model-predicted Hg water and surface sediment concentrations were found to be significantly correlated (±20%) with measured values (r(2) = 0.94, p < 0.0001, n = 13) and mechanistic model predictions (LOTOX2-Hg, r(2) = 0.95, p < 0.0001, n = 10). The predictive capacity of HERMES was previously tested on smaller (≤1 km(2)) lakes in Nova Scotia and Ontario, Canada (i.e., water and sediment Hg concentrations were ±15% of measured data). Results suggest that HERMES could be applicable to a broad range of lake sizes. Uncertainty analyses on HERMES model input variables indicated a larger atmospheric Hg contribution for Lake Ontario when compared to previous predictions for smaller lakes. PMID:21726924

  19. Pathogenesis of skin and liver neoplasms in white suckers from industrially polluted areas in Lake Ontario.

    Science.gov (United States)

    Hayes, M A; Smith, I R; Rushmore, T H; Crane, T L; Thorn, C; Kocal, T E; Ferguson, H W

    1990-05-01

    Increased prevalences of epidermal and hepatobiliary neoplasms in white suckers (Catostomu commersoni) and brown bullheads (Ictalurus nebulosus) in the Western region of Lake Ontario have been associated with industrial pollution, but the identity and causative role of environmental carcinogens have not yet been established. Most epidermal tumors of lip and body skin are benign focal proliferations that occur in fish from the polluted Hamilton region, and also in fish from less polluted sites in the Great Lakes. These skin tumors in white suckers do not have consistent alterations in cellular glutathione S-transferases (GST), suggesting that growth of skin tumors is not promoted by chemicals normally detoxified by GST. However, elevated levels of glutathione peroxidase (GPO) and glutathione reductase (GR) in skin papillomas are indicative of promotional peroxidative tissue injury, either caused directly by xenobiotics or indirectly by chemical-induced inflammation. Liver tumors in white suckers from Lake Ontario include preneoplastic, benign, and malignant populations of hepatocellular and biliary cells, all of which are more prevalent in fish from polluted sites. These liver tumors are consistently associated with chronic cholangiohepatitis and segmental cholangiofibrosis, but these conditions also occur in white suckers in non-industrial locations. Thus, the natural occurrence of biliary disease, not attributable to industrial pollution, may have some influence on the development of liver tumors. Some preneoplastic lesions and the majority of neoplastic hepatocellular and biliary lesions in white suckers have low levels of total GST, indicating that these liver neoplasms are not promoted by xenobiotics normally detoxified by hepatic GSTs.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2360036

  20. Biodiversity of Clostridium botulinum Type E Associated with a Large Outbreak of Botulism in Wildlife from Lake Erie and Lake Ontario

    OpenAIRE

    Hannett, George E.; Stone, Ward B.; Davis, Stephen W.; Wroblewski, Danielle

    2010-01-01

    The genetic relatedness of Clostridium botulinum type E isolates associated with an outbreak of wildlife botulism was studied using random amplification of polymorphic DNA (RAPD). Specimens were collected from November 2000 to December 2008 during a large outbreak of botulism affecting birds and fish living in and around Lake Erie and Lake Ontario. In our present study, a total of 355 wildlife samples were tested for the presence of botulinum toxin and/or organisms. Type E botulinum toxin was...

  1. Embryotoxicity of extracts from Lake Ontario rainbow trout (Oncorhynchus mykiss) to Japanese medaka (Oryzias latipes)

    Energy Technology Data Exchange (ETDEWEB)

    Harris, G.E.; Metcalfe, T.L.; Metcalfe, C.D. (Trent Univ., Peterborough, Ontario (Canada). Environmental and Resources Studies Program); Huestis, S.Y. (Canada Centre for Inland Waters, Burlington, Ontario (Canada))

    1994-09-01

    Various preparative techniques were used to extract nonpolar organic compounds from the muscle tissue of Lake Ontario rainbow trout (Oncorhynchus mykiss). In this extract, PCBs and organochlorine compounds were detected in nanogram-per-milliliter quantities, and polychlorinated dibenzo-p-dioxins and dibenzofurans were detected in picogram-per-milliliter quantities. The extract and various subfractions of the extract were tested for embryotoxicity in a bioassay with embryos of Japanese medaka (Oryzias latipes). The whole extract was embryotoxic to medaka, as were an extract fraction containing PCBs (fraction A) and extract fractions containing nonpolar organochlorine compounds (fractions B and C). When subfractions prepared from fraction A were tested for embryotoxicity, a subfraction containing non-ortho-substituted PCB congeners was embryo-toxic, whereas subfractions containing mono-ortho- and di-ortho-substituted PCB congeners were relatively nontoxic. Pathological lesions characteristic of exposure to planar halogenated aromatic hydrocarbons were observed only in embryos exposed to the non-ortho-PCB subfraction. The non-ortho-PCB subfraction of fraction A was more toxic than the original fraction A, which indicates that nontoxic PCBs reduce the toxicity of the non-ortho-PCBs through some unknown mechanism. This study indicates that organochlorine compounds and non-ortho-substituted PCBs have the potential to be embryotoxic to early life stages of Great lakes fish, but nontoxic contaminants can modify this toxic response. These data are relevant to the interpretation of correlations between embryo mortalities and concentrations of persistent organic contaminants in Great Lakes salmonids.

  2. Further study on source parameters at Quirke Mine, Elliot Lake, Ontario

    International Nuclear Information System (INIS)

    A further analysis on source parameters for thirty-seven mining-induced seismic events at Quirke Mine, Elliot Lake, Ontario, has been carried out to study the self-similarity assumption in scaling law of seismic spectrum for mining-induced microearthquakes, and to understand the focal mechanism in the mine. Evidence from high P-wave energy in a ratio Ep/Es of 5% to 30%, and about 80% of the events with Es/Ep L). For the same total seismic energy, the apparent stress is limited by 80 GN.m and 800 GN.m of seismic moment. The observed stress drop is dependent on the seismic moment, which implies a breakdown in scaling law for events induced by mining. An analysis of peak particle velocity and acceleration presents the evidence for seismic attenuation over the fractured zone above the rock burst area in the mine

  3. Diel periodicity of drift of larval fishes in tributaries of Lake Ontario

    Science.gov (United States)

    Johnson, J.H.; McKenna, J.E., Jr.

    2007-01-01

    Diel patterns of downstream drift were examined during mid-June in three tributaries of Lake Ontario. Larval fishes were collected in drift nets that were set in each stream for 72 consecutive hours and emptied at 4-h intervals. Fantail darter (Ethostoma flabellare) and blacknose dace (Rhinichthys atractulus) were the two most abundant native stream fishes and were two of the three species collected in the ichthyoplankton drift. Fantail darter larvae comprised 100%, 98.9%, and 70.2% of the ichthyoplankton in the three streams. Most larval fishes (96%) drifted at night with peak catches occurring at 2400h in Orwell Brook and Trout Brook and 0400h in Little Sandy Creek. Based on stream temperatures, peak spawning and larval drift of blacknose dace probably occurred later in the season.

  4. Sedimentary records of spheroidal carbonaceous particles from fossil-fuel combustion in western Lake Ontario

    Energy Technology Data Exchange (ETDEWEB)

    Lan, Y.L.; Breslin, V.T. [Syracuse University, Stony Brook, NY (USA). Marine Science Research Center

    1999-07-01

    Spheroidal carbonaceous particles (SCPs) were quantified in three sediment cores collected in the western basin of Lake Ontario to examine the impact of fossil-fuel combustion on sediment metal concentrations. SCP profiles were similar for the three cores showing the initiation of the SCP record deep in the core, followed by a rapid increase to a sub-surface maximum, and a subsequent decrease towards the sediment surface. Subsurface maximum SCP concentrations ranged from 1.97 to 5.61 x 10{sup 5} per gram dry matter/gDM. For Pb-210 dated cores, dates for the initiation of the SCP record (1850 {+-} 10 years), the initiation of the rapid rise in SCPs (1880 {+-} 13 years), and the SCP subsurface maximum (1961 {+-} 3 years) agree well. The rapid increase in sediment SCPs also agrees well with the US bituminous coal consumption during this same period (1880 to 1980). SCPs in surface sediments decreased between 55 to 83% from the subsurface maximum (1961 to 1996) in these cores while US coal usage continued to increase. SCP decreases were attributed to the increased use and efficiency of particle collection devices by utilities and industry. Lead, Cr, Cu, and Zn showed significant correlations with SCPs within each respective sediment core. Calculations show that although SCPs are not the major source of anthropogenic metals in Lake Ontario sediments, they may account for between 4 to 55% of the Zn, 1 to 12% of the Cu, 2 to 22% of the Pb and 1 to 18% of the Cr in these sediments.

  5. Windsor, Ontario Exposure Assessment Study: Design and Methods Validation of Personal, Indoor and Outdoor Air Pollution Monitoring

    Science.gov (United States)

    The Windsor, Ontario Exposure Assessment Study evaluated the contribution of ambient air pollutants to personal and indoor exposures of adults and asthmatic children living in Windsor, Ontario, Canada. In addition, the role of personal, indoor, and outdoor air pollution exposures...

  6. Lake Ontario zooplankton in 2003 and 2008: community changes and vertical redistribution

    Science.gov (United States)

    Rudstam, Lars G.; Holeck, Kristen T.; Bowen, Kelly L.; Watkins, James M.; Weidel, Brian C.; Luckey, Frederick J.

    2014-01-01

    Lake-wide zooplankton surveys are critical for documenting and understanding food web responses to ecosystem change. Surveys in 2003 and 2008 during the binational intensive field year in Lake Ontario found that offshore epilimnetic crustacean zooplankton declined by a factor of 12 (density) and factor of 5 (biomass) in the summer with smaller declines in the fall. These declines coincided with an increase in abundance of Bythotrephes and are likely the result of direct predation by, or behavioral responses to this invasive invertebrate predator. Whole water column zooplankton density also declined from 2003 to 2008 in the summer and fall (factor of 4), but biomass only declined in the fall (factor of 2). The decline in biomass was less than the decline in density because the average size of individual zooplankton increased. This was due to changes in the zooplankton community composition from a cyclopoid/bosminid dominated community in 2003 to a calanoid dominated community in 2008. The increase in calanoid copepods was primarily due to the larger species Limnocalanus macrurus and Leptodiaptomus sicilis. These coldwater species were found in and below the thermocline associated with a deep chlorophyll layer. In 2008, most of the zooplankton biomass resided in or below the thermocline during the day. Increased importance of copepods in deeper, colder water may favor cisco and rainbow smelt over alewife because these species are better adapted to cold temperatures than Alewife.

  7. The impact of acid deposition and forest harvesting on lakes and their forested catchments in south central Ontario: a critical loads approach

    Directory of Open Access Journals (Sweden)

    S. A. Watmough

    2002-01-01

    Full Text Available The impact of acid deposition and tree harvesting on three lakes and their representative sub-catchments in the Muskoka-Haliburton region of south-central Ontario was assessed using a critical loads approach. As nitrogen dynamics in forest soils are complex and poorly understood, for simplicity and to allow comparison among lakes and their catchments, CLs (A for both lakes and forest soils were calculated assuming that nitrate leaching from catchments will not change over time (i.e. a best case scenario. In addition, because soils in the region are shallow, base cation weathering rates for the representative sub-catchments were calculated for the entire soil profile and these estimates were also used to calculate critical loads for the lakes. These results were compared with critical loads obtained by the Steady State Water Chemistry (SSWC model. Using the SSWC model, critical loads for lakes were between 7 and 19 meq m-2yr-1 higher than those obtained from soil measurements. Lakes and forests are much more sensitive to acid deposition if forests are harvested, but two acid-sensitive lakes had much lower critical loads than their respective forested sub-catchments implying that acceptable acid deposition levels should be dictated by the most acid-sensitive lakes in the region. Under conditions that assume harvesting, the CL (A is exceeded at two of the three lakes and five of the six sub-catchments assessed in this study. However, sulphate export from catchments greatly exceeds input in bulk deposition and, to prevent lakes from falling below the critical chemical limit, sulphate inputs to lakes must be reduced by between 37% and 92% if forests are harvested. Similarly, sulphate leaching from forested catchments that are harvested must be reduced by between 16 and 79% to prevent the ANC of water draining the rooting zone from falling below 0 μeq l-1. These calculations assume that extremely low calcium leaching losses (9–27 μeq l-1 from

  8. Summer-autumn habitat use of yearling rainbow trout in two streams in the Lake Ontario watershed

    Science.gov (United States)

    Johnson, James H.; McKenna, James E.; Chalupnicki, Marc

    2016-01-01

    Understanding the habitat requirements of salmonids in streams is an important component of fisheries management. We examined the summer and autumn habitat use of yearling Rainbow Trout Oncorhynchus mykiss in relation to available habitat in two streams in the Lake Ontario watershed. Little interstream variation in trout habitat use was observed; the variation that did occur was largely due to differences between streams in available habitat in the autumn. In both streams, yearling Rainbow Trout utilized pool habitat and during periods of high stream discharge were associated with larger substrate that may provide a velocity barrier. These findings may assist resource managers in their efforts to protect and restore habitat for migratory Rainbow Trout in the Lake Ontario watershed.

  9. Distinguishing wild vs. stocked lake trout (Salvelinus namaycush) in Lake Ontario: Evidence from carbon and oxygen stable isotope values of otoliths

    Science.gov (United States)

    Schaner, T.; Patterson, W.P.; Lantry, B.F.; O'Gorman, R.

    2007-01-01

    We investigated the potential for using carbon and oxygen isotope values of otolith carbonate as a method to distinguish naturally produced (wild) lake trout (Salvelinus namaycush) from hatchery-reared lake trout in Lake Ontario. We determined δ 13C(CaCO3) and δ 18O(CaCO3) values of otoliths from juvenile fish taken from two hatcheries, and of otoliths from wild yearlings. Clear differences in isotope values were observed between the three groups. Subsequently we examined otoliths from large marked and unmarked fish captured in the lake, determining isotope values for regions of the otolith corresponding to the first year of life. Marked (i.e., stocked) fish showed isotope ratios similar to one of the hatchery groups, whereas unmarked fish, (wild fish or stocked fish that lost the mark) showed isotope ratios similar either to one of the hatchery groups or to the wild group. We interpret these data to suggest that carbon and oxygen isotope values can be used to determine the origin of lake trout in Lake Ontario, if a catalogue of characteristic isotope values from all candidate years and hatcheries is compiled.

  10. Lakewide estimates of alewife biomass and Chinook salmon abundance and consumption in Lake Ontario, 1989–2005: implications for prey fish sustainability

    Science.gov (United States)

    Murry, Brent A.; Connerton, Michael J.; O'Gorman, Robert; Stewart, Donald J.; Ringlerd, Neil H.

    2010-01-01

    Stocking levels of Chinook salmon Oncorhynchus tshawytscha for Lake Ontario have been highly controversial since the early 1990s, largely because of uncertainties about lakewide abundance and rates of prey consumption. Previous estimates have focused on years before 1995; since then, however, the Lake Ontario ecosystem has undergone substantial changes, and there is new evidence of extensive natural recruitment. Presented here are new abundance estimates of Chinook salmon and alewives Alosa pseudoharengus in Lake Ontario and a reevaluation of the potential risk of alewife population collapse. We found that Lake Ontario has been supporting, on average (1989–2005), 1.83 × 106 (range, 1.08 × 106 to 3.24 × 106) Chinook salmon of ages 1–4, amounting to a mean annual biomass of 11.33 × 103 metric tons (range, 5.83 × 103 to 23.04 × 103 metric tons). During the same period (1989–2005), the lake supported an alewife biomass of 173.66 × 103 metric tons (range, 62.37 × 103 to 345.49 × 103 metric tons); Chinook salmon of ages 1–4 consumed, on average, 22% (range, 11–44%) of the alewife biomass annually. Because our estimates probably underestimate total consumption and because Chinook salmon are only one of several salmonine species that depend on alewives, predation pressure on the Lake Ontario alewife population may be high enough to raise concerns about long-term stability of this predator–prey system.

  11. Ontario Hydro's experience in linking sustainable development, full cost accounting and environmental assessment

    International Nuclear Information System (INIS)

    Ontario Hydro's mission is ''to make Ontario Hydro a leader in energy efficiency and sustainable development, and to provide its customers with safe and reliable energy services at competitive prices''. In April 1995, Ontario Hydro's Board of Directors approved a sustainable energy development (SED) policy, guiding principles and strategic guidelines that elaborate on Ontario Hydro's commitment to sustainable development as expressed in the mission statement. This policy provides the framework for operational sustainable development. One of Ontario Hydro's guiding principles for SED is integration of environmental and social factors into planning, decision making and business practices. Full cost accounting is a tool used at Ontario Hydro to achieve this integration. Ontario Hydro's approach to full cost accounting has two components: (1) to better define and allocate the internal environmental costs; and (2) to better define and cost the externalities associated with its activities. Three examples are provided of Ontario Hydro's success in integrating environmental considerations into its planning and decision making: (a) A set of SED decision criteria are applied to business case analyses for investment proposals. The SED decision criteria focus on five components for investment decisions: maximizing resource use and energy efficiency, reducing environmental damage/impacts, avoiding/improving social impacts, increasing the use of renewable technologies, and identifying financial gains attributable to sustainable development initiatives. (b) The environmental assessment for the Corporate Integrated Resource Plan was performed on an environmental damage basis consistent with Ontario Hydro's corporate guidelines for full cost accounting. The results of the environmental assessment were combined with fourteen other measures using multicriteria analysis to evaluate alternative system plans. (c) A study was undertaken to examine the potential externalities associated

  12. Erosional dynamics and morphological analysis along the southeastern Lake Ontario shoreline, New York state

    International Nuclear Information System (INIS)

    Glacial drumlins, trending near perpendicular to the southeastern shore of Lake Ontario, display two distinct forms of coastal erosion. Some drumlins are eroding into beachfront bluffs that feature amphitheater-shaped gullies with steep headwalls and moderately sloping floors, separated by narrow, resistant, steep-sided ridges. Other drumlins of similar till composition, vegetative cover, and wave exposure are eroding into bluff's characterized by steep, planar (i.e., ungullied) surfaces. Aerial photograph and topographic analyses, combines with field observations, clearly indicate that the dominant factors controlling these morphological differences are bluff height and the manner of erosional retreat. The large volume of sediments supplied to the base of high (>30 m) bluffs creates broad (≤15 m) and thick (≤2 m) colluvial terraces between the beach and bluff base. Except during severe storms, these colluvial deposits reduce or prevent wave undercutting of the cliff base and subsequent slumping of the cliff face. This results in channeling and headward erosion of the bluff faces that, in time, evolve into a deeply incensed (>10 m) gully system. In contrast, at the base of low (<20 m) bluffs, colluvial beach terraces are smaller (≤10 m broad; <0.5 m thick) or nonexistent because the rate of wave erosion exceeds the rate of sediment supply from the bluffs. Thus, the gullying effects of surface water runoff, mud flows, rain and wind attack, so influential on high bluffs, are overwhelmed by the frequency of the slumping and sliding processes, producing planar morphologies on low-lying bluffs. Drumlin bluffs of intermediate height are affected by both slumping and gullying processes, and tend to develop a quasi-planar channeled surface

  13. Shifts in the diet of Lake Ontario alewife in response to ecosystem change

    Science.gov (United States)

    Stewart, T.J.; Sprules, W.G.; O'Gorman, R.

    2009-01-01

    In the 1990s, the Lake Ontario ecosystem was dramatically altered due to continued invasions of exotic species including dreissenid mussels and predatory cladocerans. We describe the diet and biomass of prey in the stomachs of adult (≥ 109 mm TL) and sub-adult (Alosa pseudoharengus) in 2004 and 2005 across seasons and depths and compare our results to data from 1972 to 1988. During 2004 and 2005, adult alewife consumed primarily zooplankton prey at bottom depth zones Mysis at bottom depth zones > 70 m. Mysis dominated the diets of adult alewife in all seasons except during the summer of 2004 when zooplankton dominated. Mysis dominated the diets of sub-adult alewife during early and late spring and zooplankton dominated the diets in summer and fall. Bythotrephes and Cercopagis were observed in the diets of both sub-adult and adult alewife. Diporeia was observed only rarely in adult alewife diets. The biomass of prey in alewife stomachs varied seasonally and increased with bottom depth for adult alewife. Alewife diets in 2004–2005 differed from those in 1972 and 1988 with an increase in the prevalence of Mysis, and a decline in the prevalence of zooplankton. The biomass of prey in adult alewife stomachs declined in 2004 and 2005 compared to 1972 and 1988, at bottom depth zones 70 m suggesting reduced food availability closer to shore. We hypothesize that consumption levels at the shallower depth zones, as indicated by very low biomass of prey in alewife stomachs, may not be sufficient to sustain alewife growth. The increased prevalence of Mysis and common occurrence of predatory cladocerans in the diet of alewife means that alewife have shifted to a higher trophic position.

  14. Stereo Pair of Height as Color & Shaded Relief, New York State, Lake Ontario to Long Island

    Science.gov (United States)

    2000-01-01

    From Lake Ontario and the St. Lawrence River (at the top of the image) and extending to Long Island (at the bottom) this image shows the varied topography of eastern New York State and parts of Massachusetts, Connecticut, Pennsylvania and New Jersey. The high 'bumpy' area in the middle to top right is the southern and western Adirondack Mountains, a deeply eroded landscape that includes the oldest exposed rocks in the eastern U.S.On the left side is the Catskill Mountains, a part of the Appalachian Mountain chain, where river erosion has produced an intricate pattern of valleys. Between the Adirondacks and Catskills is a wide valley that contains the Mohawk River and the Erie Canal. On the northwest (top) of the Catskills are several long, narrow lakes, some of the Finger Lakes of central New York that were carved by the vast glacier that covered this entire image as recently as 18,000 years ago.The Hudson River runs along a straight valley from right center (near Glens Falls), widening out as it approaches New York City at the lower left on the image. The Connecticut River valley has a similar north-south trend further to the east (across the lower right corner of the image). The Berkshires are between the Hudson and Connecticut valleys. Closer to the coast are the more deeply eroded rocks of the area around New York City, where several resistant rock units form topographic ridges.This image product is derived from a preliminary SRTM elevation model, processed with preliminary navigation information from the Space Shuttle. Broad scale and fine detail distortions in the model seen here will be corrected in the final elevation model.This stereoscopic image was generated by first creating and combining a shaded relief image and a height as color image, both of which were derived from the elevation model. Large water bodies were then masked, and the result was then draped back over the elevation model. Two differing perspectives were then calculated, one for each eye

  15. Racetrack and Bonnie Claire: southwestern US playa lakes as analogs for Ontario Lacus, Titan

    OpenAIRE

    Lorenz, Ralph D.; Jackson, Brian; Hayes, Alex

    2010-01-01

    We note the geomorphological and meteorological processes at Racetrack Playa, Death Valley National Park, as analogs for those at Ontario Lacus on Titan. Although Ontario is ~50× larger, the planforms of the two features are nearly identical, both are extremely flat, and are in environments where infrequent rainfall occurs against a climate, where evaporation exceeds precipitation. While the famous moving rocks on the Racetrack Playa may be exceptional on the Earth, the lower gravity and thic...

  16. Tracking the History and Ecological Changes of Rising Double-Crested Cormorant Populations Using Pond Sediments from Islands in Eastern Lake Ontario.

    Directory of Open Access Journals (Sweden)

    Emily M Stewart

    Full Text Available In the Laurentian Great Lakes region, the double-crested cormorant (Phalacrocorax auritus has seen a thousand-fold population increase in recent decades. These large colonies of birds now often conflict with socioeconomic interests, particularly due to perceived competition with fisheries and the destruction of terrestrial vegetation in nesting habitats. Here we use dated sediment cores from ponds on islands in eastern Lake Ontario that receive waste inputs from dense colonies of cormorants and ring-billed gulls (Larus delawarensis to chronicle the population rise of these species and assess their long-term ecological impacts. Modern water chemistry sampling from these sites reveals drastically elevated nutrient and major ion concentrations compared to reference ponds not influenced by waterbirds. Geochemical tracers in dated sediment cores, particularly δ15N and chlorophyll-a concentrations, track waterbird influences over time. Fossil diatom assemblages were dominated by species tolerant of hyper-eutrophic and polluted systems, which is in marked contrast to assemblages in reference sites. In addition to establishing long-term ecological impacts, this multi-proxy paleoecological approach can be used to determine whether islands of concern have been long-term nesting sites or were only recently colonized by cormorant or ring-billed gull populations across the Great Lakes, facilitating informed management decisions about controversial culling programs.

  17. contaminant migration in a sand aquifer near an inactive uranium tailings impoundment, Elliot Lake, Ontario

    International Nuclear Information System (INIS)

    An investigation of the movement of contaminated groundwater from inactive uranium tailings through a sand aquifer is being conducted at the Nordic Main tailings impoundment near Elliot Lake, Ontario. During 1979 and 1980, multilevel bundle-type piezometers were installed at several locations around the edge of the tailings impoundment. Chemical analysis of water samples from the bundle piezometers indicate that a major contaminant plume extends outward through a sand aquifer from the southeastern part of the Nordic Main impoundment dam. In the vincinity of the contaminant plume, the sand aquifer varies in thickness from about 9 to 15 m. The plume has two distinct segments, referred to as the inner core and the outer zone. The inner core, which has a pH of 4.3-5.0 and extends about 15 m from the foot of the tailings dam, contains several grams per litre of iron and sulfate, and tens of pCi/L of 226Ra and 210Pb. Water levels in piezometers within the inner core show that groundwater is moving horizontally, away from the tailings impoundment, with a velocity of up to several hundred metres per year. The outer zone, which extends a few hundred metres downgradient from the dam, is characterized by hundreds to thousands of milligrams per litre of iron and sulfate, less than 15pCi/L of 226Ra, and a pH greater than 5.7. Comparison of 1979 and 1980 data shows that the front of the inner core is advancing a few metres per year, which is less than a few percent of the groundwater velocity. This retardation of movement of the inner core is caused by neutralization of the acidic water as a result of dissolution of calcium carbonate in the sand. With the rise in pH, precipitation of iron carbonate and possibly some iron hydroxide occurs and the contaminants of main concern such as 226Ra, 210Pb, and uranium are removed from solution by adsorption or coprecipitation

  18. Groundwater quality in the Eastern Lake Ontario Basin of New York, 2008

    Science.gov (United States)

    Risen, Amy J.; Reddy, James E.

    2011-01-01

    Water samples were collected from nine production wells and nine private residential wells in the Eastern Lake Ontario Basin of New York from August through October 2008 and analyzed to characterize the chemical quality of groundwater. The wells were selected to provide adequate spatial coverage of the 3,225-square-mile study area; areas of greatest groundwater use were emphasized. Eight of the 18 wells sampled, were screened in sand and gravel aquifers, and 10 were finished in bedrock aquifers. The samples were collected and processed by standard U.S. Geological Survey procedures and were analyzed for 223 physical properties and constituents, including major ions, nutrients, trace elements, radon-222, pesticides, volatile organic compounds (VOCs), and indicator bacteria. Water quality in the study area is generally good, but concentrations of some constituents exceeded current or proposed Federal or New York State drinking-water standards; these were: color (2 samples), pH (1 sample), sodium (5 samples), chloride (1 sample), aluminum (2 samples), iron (5 unfiltered samples), manganese (3 samples), radon-222 (13 samples), and bacteria (4 samples). Dissolved-oxygen concentrations in samples from wells finished in sand and gravel [median 3.8 milligrams per liter (mg/L)] were greater than those from wells finished in bedrock (median less than 0.7 mg/L). The pH of all samples was typically neutral or slightly basic (median 7.4); the median water temperature was 11.3 degrees Celsius. The ions with the highest concentrations were bicarbonate (median 174 mg/L) and calcium (median 24.1 mg/L). Groundwater in the basin ranges from soft to moderately hard [less than or equal to 120 mg/L as CaCO3] and median hardness was 90 mg/L as CaCO3. Concentrations of nitrate plus nitrite in samples from sand and gravel wells (median concentration 0.42 mg/L as nitrogen) were generally higher than those in samples from bedrock wells (median standard of 300 pCi/L. Five pesticides and

  19. A study on the levels of radioactivity in fish samples from the experimental lakes area in Ontario, Canada.

    Science.gov (United States)

    Chen, Jing; Rennie, Michael D; Sadi, Baki; Zhang, Weihua; St-Amant, Nadereh

    2016-03-01

    To better understand background radiation levels in country foods, a total of 125 fish samples were collected from three lakes (Lake 226, Lake 302 and Lake 305) in the Experimental Lakes Area (ELA) in Ontario of Canada during the summer of 2014. Concentrations of naturally occurring radionuclides ((226)Ra, (210)Pb and (210)Po) as well as anthropogenic radionuclides ((134)Cs and (137)Cs) were measured. This study confirmed that (210)Po is the dominant contributor to radiation doses resulting from fish consumption. While concentrations of (210)Pb and (226)Ra were below conventional detection limits, (210)Po was measured in almost all fish samples collected from the ELA. The average concentration was about 1.5 Bq/kg fresh weight (fw). None of the fish samples analysed in this study contained any detectable levels of (134)Cs. An average (137)Cs level of 6.1 Bq/kg fw was observed in freshwater fishes harvested in the ELA, almost twice that of samples measured in the National Capital Region of Canada in 2014 and more than 20 times higher than the levels observed in marine fish harvested from the Canadian west coast in 2013 and 2014. However, it is important to note that the concentrations of (137)Cs in fish samples from these inland lakes are considered very low from a radiological protection perspective. The resulting radiation dose for people from fish consumption would be a very small fraction of the annual dose from exposure to natural background radiation in Canada. The results indicate that fishes from inland lakes do not pose a radiological health concern. PMID:26803403

  20. Cattail invasion of sedge/grass meadows in Lake Ontario: Photointerpretation analysis of sixteen wetlands over five decades

    Science.gov (United States)

    Wilcox, D.A.; Kowalski, K.P.; Hoare, H.L.; Carlson, M.L.; Morgan, H.N.

    2008-01-01

    Photointerpretation studies were conducted to evaluate vegetation changes in wetlands of Lake Ontario and the upper St. Lawrence River associated with regulation of water levels since about 1960. The studies used photographs from 16 sites (four each from drowned river mouth, barrier beach, open embayment, and protected embayment wetlands) and spanned a period from the 1950s to 2001 at roughly decadal intervals. Meadow marsh was the most prominent vegetation type in most wetlands in the late 1950s when water levels had declined following high lake levels in the early 1950s. Meadow marsh increased at some sites in the mid-1960s in response to low lake levels and decreased at all sites in the late 1970s following a period of high lake levels. Typha increased at nearly all sites, except wave-exposed open embayments, in the 1970s. Meadow marsh continued to decrease and Typha to increase at most sites during sustained higher lake levels through the 1980s, 1990s, and into 2001. Most vegetation changes could be correlated with lake-level changes and with life-history strategies and physiological tolerances to water depth of prominent taxa. Analyses of GIS coverages demonstrated that much of the Typha invasion was landward into meadow marsh, largely by Typha x glauca. Lesser expansion toward open water included both T. x glauca and T. angustifolia. Although many models focus on the seed bank as a key component of vegetative change in wetlands, our results suggest that canopy-dominating, moisture-requiring Typha was able to invade meadow marsh at higher elevations because sustained higher lake levels allowed it to survive and overtake sedges and grasses that can tolerate periods of drier soil conditions.

  1. Late Quaternary seismo-stratigraphy of Lake Wanapitei, Sudbury, Ontario, Canada: Arguments for a possible meteorite impact origin

    Science.gov (United States)

    Lazorek, Michael; Eyles, Nick; Eyles, Carolyn; Doughty, Mike; L'Heureux, Elizabeth; Milkereit, Berndt

    2006-12-01

    Lake Wanapitei (132.75 km2) fills what has been identified as an Eocene (c. 37 Ma) meteorite impact basin in the Canadian Shield near Sudbury, Ontario, Canada. The area was glaciated many times during the Pleistocene and the basin lies immediately north of the prominent Cartier Moraine built during the last glaciation by the retreating Laurentide Ice Sheet some 11,000 years ago. Study of the deeper geophysics of the basin using magnetic and gravity techniques, and confirmation of its origin, is hampered by lack of data regarding water depths, the form of the bedrock surface and the thickness and character of glacial and postglacial sediment. To this end, more than 300 km of high-resolution single channel seismic chirp and 200 kHz bathymetric data were collected from the basin in the summer of 2002. Water depths reach a maximum of 118 m and acoustic basement is defined by a glacially scoured bedrock surface. The overlying Pleistocene sediment fill exceeds 35 m in thickness and consists of a lowermost late-glacial succession of rhythmically laminated silty clays deposited when the basin was flooded by a deep and regionally extensive ice dammed water body (Glacial Lake Algonquin). Truncation of the upper surface of this succession across large parts of the lake floor records the drainage of Lake Algonquin and the isolation of Wanapitei Lake as a separate water body. Overlying Holocene sediment is up to 10 m thick but is markedly discontinuous and commonly occurs as mounded ‘drifts’ reflecting strong bottom currents and low inputs of modern sediment. The presence of apparently undisturbed Precambrian bedrock below large portions of the lake basin places significant constraints on the dimensions of any meteorite impact structure.

  2. A telephone survey of eel fishermen regarding external lesions and mortalities of American eels (Anguilla rostrata) from Lake Ontario and the St. Lawrence River basin, Canada.

    Science.gov (United States)

    Dutil, L; Bélanger, D; Couillard, C M

    1997-07-01

    Signs of decreasing landings and recruitment have been observed during the last decade in American eels (Anguilla rostrata) from the St. Lawrence River basin, Canada. A study was undertaken to examine whether important manifestational diseases among commercial catches could be associated with these declines. During this survey, 56 fishermen from Lakes Ontario, Saint-François and Saint-Pierre, the Richelieu River, the Québec City area and the St. Lawrence Estuary were interviewed. Most fishermen from every area reported decreasing catches since the 1980s. Eel mortalities were reported from 1990 to 1992 in Lake Saint-François, Lake Saint-Pierre and the Québec City area, but in apparently lower magnitude than in the past decades. The lesions observed on dead eels in Lake Saint-François indicated that the cause of the mortalities might be associated with the upstream hydroelectric dam. Eels with 'scratches all over the body' were only observed in the St. Lawrence Estuary. Fishermen from almost every area reported that they had observed eels with 'crooked tail', 'humpback' and 'cut tail' in low frequency in 1992. The questionnaire data were validated by comparing some of the results of the questionnaire survey and a processing plant survey in 1992. The use of questionnaires for assessing fish diseases in commercial species is discussed. The results of this survey do not indicate that the health of the American eels from the St. Lawrence River basin is severely impaired. However, the magnitude of diseases and mortalities was probably underestimated. PMID:9234424

  3. Biodiversity of Clostridium botulinum type E associated with a large outbreak of botulism in wildlife from Lake Erie and Lake Ontario.

    Science.gov (United States)

    Hannett, George E; Stone, Ward B; Davis, Stephen W; Wroblewski, Danielle

    2011-02-01

    The genetic relatedness of Clostridium botulinum type E isolates associated with an outbreak of wildlife botulism was studied using random amplification of polymorphic DNA (RAPD). Specimens were collected from November 2000 to December 2008 during a large outbreak of botulism affecting birds and fish living in and around Lake Erie and Lake Ontario. In our present study, a total of 355 wildlife samples were tested for the presence of botulinum toxin and/or organisms. Type E botulinum toxin was detected in 110 samples from birds, 12 samples from fish, and 2 samples from mammals. Sediment samples from Lake Erie were also examined for the presence of C. botulinum. Fifteen of 17 sediment samples were positive for the presence of C. botulinum type E. Eighty-one C. botulinum isolates were obtained from plants, animals, and sediments; of these isolates, 44 C. botulinum isolates produced type E toxin, as determined by mouse bioassay, while the remaining 37 isolates were not toxic for mice. All toxin-producing isolates were typed by RAPD; that analysis showed 12 different RAPD types and multiple subtypes. Our study thus demonstrates that multiple genetically distinct strains of C. botulinum were involved in the present outbreak of wildlife botulism. We found that C. botulinum type E is present in the sediments of Lake Erie and that a large range of bird and fish species is affected. PMID:21115703

  4. Numerical study of tides in Ontario Lacus, a hydrocarbon lake on the surface of the Saturnian moon Titan

    Science.gov (United States)

    Vincent, David; Karatekin, Özgur; Vallaeys, Valentin; Hayes, Alexander G.; Mastrogiuseppe, Marco; Notarnicola, Claudia; Dehant, Véronique; Deleersnijder, Eric

    2016-04-01

    In the context of the emergence of extra-terrestrial oceanography, we adapted an existing oceanographic model, SLIM (www.climate.be/slim), to the conditions of Titan, a moon of Saturn. The tidal response of the largest southern lake at Titan's surface, namely Ontario Lacus, is simulated. SLIM solves the 2D, depth-averaged shallow water equations on an unstructured mesh using the discontinuous Galerkin finite element method, which allows for high spatial resolution wherever needed. The impact of the wind forcing, the bathymetry, and the bottom friction is also discussed. The predicted maximum tidal range is about 0.56 m in the southern part of the lake, which is more than twice as large as the previous estimates (see Tokano, Ocean Dyn 60:(4) 803-817 10.1007/s10236-010-0285-3 (Tokano 2010)). The patterns and magnitude of the current are also markedly different from those of previous studies: the tidal motion is not aligned with the major axis of the lake and the speed is larger nearshore. Indeed, the main tidal component rotates clockwise in an exact period of one Titan day and the tidal currents can reach 0.046 ms -1 close to the shores depending on the geometry and the bathymetry. Except for these specific nearshore regions, the current speed is less than 0.02 ms -1. Circular patterns can be observed offshore, their rotational direction and size varying along the day.

  5. Predation on Pacific salmonid eggs and carcass's by subyearling Atlantic salmon in a tributary of Lake Ontario

    Science.gov (United States)

    Johnson, James H.; Chalupnicki, Marc A.; Abbett, Ross; Verdoliva, Francis

    2016-01-01

    A binational effort to reintroduce Atlantic salmon (Salmo salar) that were extirpated in the Lake Ontario ecosystem for over a century is currently being undertaken by the New York State Department of Environmental Conservation and the Ontario Ministry of Natural Resources. Reintroduction actions include the release of several life stages including fry, fall fingerlings, and yearling smolts. In this study we describe the diet of recently released fall fingerling Atlantic salmon in a tributary of the Salmon River, New York. A specific objective of the study was to determine if juvenile Atlantic salmon would utilize the high caloric food source provided by introduced Pacific salmonids (Oncorhynchus spp.) that includes eggs and carcass flesh. Salmon eggs and carcass flesh comprised 20.5% of the October to January diet in 2013–14 and 23.9% in 2014–15. The consumption of steelhead (O. mykiss) eggs was a major part of the diet in April in both 2014 (54.1%) and 2015 (33.2%). This study documented that recently released Atlantic salmon will consume the high caloric food material provided by Pacific salmonids and that the consumption of this material extends for several months.

  6. Groundwater quality in the Chemung River, Eastern Lake Ontario, and Lower Hudson River Basins, New York, 2013

    Science.gov (United States)

    Scott, Tia-Marie; Nystrom, Elizabeth A.; Reddy, James E.

    2015-11-10

    In a study conducted by the U.S. Geological Survey (USGS) in cooperation with the New York State Department of Environmental Conservation, water samples were collected from 4 production wells and 4 domestic wells in the Chemung River Basin, 8 production wells and 7 domestic wells in the Eastern Lake Ontario Basin, and 12 production wells and 13 domestic wells in the Lower Hudson River Basin (south of the Federal Lock and Dam at Troy) in New York. All samples were collected in June, July, and August 2013 to characterize groundwater quality in these basins. The samples were collected and processed using standard USGS procedures and were analyzed for 148 physiochemical properties and constituents, including dissolved gases, major ions, nutrients, trace elements, pesticides, volatile organic compounds, radionuclides, and indicator bacteria.

  7. Examination of the influence of juvenile Atlantic salmon on the feeding mode of juvenile steelhead in Lake Ontario tributaries

    Science.gov (United States)

    Johnson, James H.; Waldt, Emily M.

    2014-01-01

    We examined diets of 1204 allopatric and sympatric juvenile Atlantic salmon (Salmo salar) and steelhead (Oncorhynchus mykiss) in three tributaries of Lake Ontario. The diet composition of both species consisted primarily of ephemeropterans, trichopterans, and chironomids, although juvenile steelhead consumed more terrestrial invertebrates, especially at the sympatric sites. Subyearlings of both species consumed small prey (i.e. chironomids) whereas large prey (i.e. perlids) made up a higher percentage of the diet of yearlings. The diet of juvenile steelhead at the allopatric sites was more closely associated with the composition of the benthos than with the drift, but was about equally associated with the benthos and drift at the sympatric sites. The diet of both subyearling and yearling Atlantic salmon was more closely associated with the benthos than the drift at the sympatric sites. The evidence suggests that juvenile steelhead may subtly alter their feeding behavior in sympatry with Atlantic salmon. This behavioral adaptation may reduce competitive interactions between these species.

  8. A comparative analysis of double-crested cormorant diets from stomachs and pellets from two Lake Ontario colonies

    Science.gov (United States)

    Johnson, James H.; Ross, Robert M.; McCullough, Russell D.; Mathers, Alastair

    2010-01-01

    Double-crested cormorant (Phalacrocorax auritus) diets were compared with evidence from the stomachs of shot birds and from regurgitated pellets at High Bluff Island and Little Galloo Island, Lake Ontario. The highest similarity in diets determined by stomach and pellet analyses occurred when both samples were collected on the same day. Diet overlap dropped substantially between the two methods when collection periods were seven to ten days apart, which suggested differences in prey availability between the two periods. Since the average number of fish recovered in pellets was significantly higher than that in stomachs, use of pellets to determine fish consumption of double-crested cormorants may be more valid than stomach analysis because pellet content represent an integrated sampling of food consumed over approximately 24 hours.

  9. Health impact assessment of Ontario's green energy and green economy act. The roles of environmental informatics in sustainability

    International Nuclear Information System (INIS)

    Renewable energy received a boost in Ontario, Canada with the Green Energy and Green Economy Act (GEGEA), ushering in a new Feed-in-Tariff (FIT) program modelled on programs from Germany, Spain, Denmark and other jurisdictions. Information about lessons learned elsewhere has clearly benefited the Ontario experience. Part of the Ontario program included streamlining the impact assessment process to facilitate the swift development of provincial renewable energy capacities. In this context, the GEGEA has been remarkably successful, generating renewable energy sector capacities, resources, projects and their spin-off benefits in Ontario, along with more sustainable electricity system. Environmentalists along with industry continue to laud the benefits of renewable energy and the GEGEA, and with good reason. Renewable energy generation in Ontario has grown from to 2 per cent in 2012 and is expected to reach 10 per cent in 2013. (orig.)

  10. Nearshore human interventions reverse patterns of decline in lake calcium budgets in central Ontario as demonstrated by mass-balance analyses

    Science.gov (United States)

    Yao, Huaxia; McConnell, Christopher; Somers, Keith M.; Yan, Norman D.; Watmough, Shaun; Scheider, Wolfgang

    2011-06-01

    Calcium (Ca) has declined to levels threatening aquatic biota in lakes on the eastern Canadian Shield. Predictive models for future changes in lake Ca are generally based on catchment-scale studies, but these models rarely account for unmeasured sources of Ca supply that are common in the nearshore areas of developed lakes. In this study we utilize up to 29 years of hydrological and water chemistry data for three lakes in central Ontario that differ in degree of human intervention to demonstrate that shoreline development may exert large effects on Ca mass balances. In the relative absence of shoreline development, Red Chalk Lake exhibited what we consider to be the normal response, a reduction in Ca load from the catchment over the last three decades, leading to a reduction in lake export and lake Ca concentration. Calcium load, export, and lake water Ca concentration also fell in Harp Lake, but less than in Red Chalk Lake, because Ca loads were elevated by human activities in Harp Lake's moderately developed shoreline area. By contrast, Dickie Lake experienced an exceptional change in Ca dynamics: both export and lake concentrations rose because of elevated load from the shoreline area linked to the use of dust suppressants on gravel roads. Reductions in both stream Ca concentration and flow volume have led to calcium decline in streams and lakes. Long-term soil acidification processes and climatic variability with its link to hydrology can explain the general pattern of Ca decline in lakes on the south-central Canadian Shield. However, given the widespread lakeshore development and use of dust suppressants on gravel roads, predictions of lake Ca levels need to take into account nearshore activities, especially those that augment rates of Ca supply.

  11. Preliminary results: shale gas assessment project of the Kettle Point formation, Southern Ontario

    Energy Technology Data Exchange (ETDEWEB)

    Beland Otis, Catherine [Ontario Geological Survey (Canada)

    2010-07-01

    The Kettle Point formation, situated in southern Ontario, is an Upper Devonian unit. In the course of a project of the Ontario Geological Survey, the formation was identified, amongst others, as a promising shale gas unit, due to its high organic content. The formation was therefore selected for the second phase of this study, which aimed at assessing its shale gas potential. Two boreholes have were drilled and sampled and a core sample was collected. The samples were stored in a specialized canister and analyzed for gas concentration and other important parameters. Results showed an important difference in gas quantities in the two wells, indicating that the gas has two origins within the formation. The preliminary results are not sufficient to determine if the formation is economically viable. This study constitutes a step towards the assessment of the gas potential of the Kettle Point formation and further hydrogeological work needs to be undertaken.

  12. Binational ecological risk assessment of bigheaded carps (Hypophthalmichthys spp.) for the Great Lakes Basin.

    Science.gov (United States)

    Cudmore, B.; Mandrak, N.E.; Dettmers, J.; Chapman, D.C.; Kolar, C.S.

    2012-01-01

    Bigheaded carps (Bighead and Silver carps) are considered a potential threat to the Great Lakes basin. A binational ecological risk assessment was conducted to provide scientifically defensible advice for managers and decision-makers in Canada and the United States. This risk assessment looked at the likelihood of arrival, survival, establishment, and spread of bigheaded carps to obtain an overall probability of introduction. Arrival routes assessed were physical connections and human-mediated releases. The risk assessment ranked physical connections (specifically the Chicago Area Waterway System) as the most likely route for arrival into the Great Lakes basin. Results of the risk assessment show that there is enough food and habitat for bigheaded carp survival in the Great Lakes, especially in Lake Erie and productive embayments in the other lakes. Analyses of tributaries around the Canadian Great Lakes and the American waters of Lake Erie indicate that there are many suitable tributaries for bigheaded carp spawning. Should bigheaded carps establish in the Great Lakes, their spread would not likely be limited and several ecological consequences can be expected to occur. These consequences include competition for planktonic food leading to reduced growth rates, recruitment and abundance of planktivores. Subsequently this would lead to reduced stocks of piscivores and abundance of fishes with pelagic, early life stages. Overall risk is highest for lakes Michigan, Huron, and Erie, followed by Lake Ontario then Lake Superior. To avoid the trajectory of the invasion process and prevent or minimize anticipated consequences, it is important to continue to focus efforts on reducing the probability of introduction of these species at either the arrival, survival, establishment, or spread stage (depending on location).

  13. Species-level and community-level data analyses reveal spatial differences and temporal change in the crustacean zooplankton of a large Canadian lake (Lake Simcoe, Ontario

    Directory of Open Access Journals (Sweden)

    Claudiu TUDORANCEA

    2001-08-01

    Full Text Available Consensus-building univariate and multivariate data analyses were used to identify patterns in space and time over seven years among 12 sampling stations in a 720 km2 hardwater Canadian lake (Lake Simcoe, Ontario, Canada. There were 15 copepods and 26 cladoceran species identified in samples collected throughout the May-October periods of 1986-1992 from Lake Simcoe. Eleven crustacean zooplankters accounted for 88% of the total average density of all recorded species in the lake. Most of these (the main exceptions being Eubosmina coregoni and Daphnia pulicaria are ubiquitous taxa with wide environmental tolerances. Multivariate analyses of these data identified spatial differences and a temporal trend in community composition. The use of Cao et al.’s (1997a "CY-dissimilarity" measure combined with Ward's Linkage clustering algorithm and non-metric multidimensional scaling ordination resulted in several clearly defined groups of sampling units (SUs, which apparently were separated predominantly on the basis of variables related to space (sampling station and time (year. The 7-year record suggested several lines of evidence for trends in community structure. Averaged over all stations, the yearly intra-station dissimilarities steadily increased 78% by 1992. The greatest rates of increase in yearly intra-station dissimilarity with 1986 baselines were found for the deeper sampling stations. These whole community-level trends were the net results of a many different patterns of change identified in species-level analyses. Such patterns included increasing densities over the 7-year period of Daphnia longiremis and Diaphanosoma birgei and declining densities of Daphnia pulicaria. Many other taxa showed highest values in the middle years of the study. Community-level temporal trends were least evident at sampling locations in the shallower and warmer Cook’s Bay, despite clear trends in several individual species. A significantly greater

  14. Impact of a river system on carbon sedimentation and sequestration in Cook's Bay of Lake Simcoe, Ontario

    Science.gov (United States)

    Blodau, Christian; Agethen, Svenja; Spangenberg, Ines; Broder, Tanja; Gimbel, Nicole; Strauss, Harald; Knorr, Klaus-Holger

    2016-04-01

    The influence of sedimentation rates and organic matter quality on carbon sequestration and mineralization at the land-water interface of lakes is not well understood. To study this issue we investigated shallow Cook's Bay of temperate Lake Simcoe in southern Ontario. The elongated bay provides gradients in morphometry, trophic level, and distance to a major tributary as a potential point source of nutrients and terrestrial organic carbon. At five sampling sites of increasing distance to the river outlet the water column was examined during stratification regarding physio-chemical parameters, dissolved organic matter (DOM) characteristics, sedimentation rates and mineralization of settling material and sediments. To quantify actual organic carbon burial, sedimentation rates and mineralization were determined in situ and by diffusive flux modeling. Long-term carbon burial and sedimentation rates were determined using 210Pb dated sediment cores. Organic carbon quality and origin were analyzed in water samples via fluorescence spectroscopy, solid DOM and settling particles via elemental analysis and 13C isotopic data. Results showed that actual and long-term carbon burial were highest at the central sites of the transect (52-63%) and lowest at the profundal sites (0-25%). Current organic carbon deposition was highest near the river outlet (max. 0.3 g C m-2 d-1) and there the settling material reaching the sediments and in the sediments was also most highly decomposable. Total sedimentation rates and organic carbon burial were closely related. Compared to the outer sites, the DOM quality was significantly different at the site closest to the river outlet but already strongly influenced by lacustrine carbon cycling. Permanent organic carbon burial was mainly influenced by sedimentation related to lake morphometry and dependent parameters. The relation between sedimentation and carbon burial rates underlined the importance of oxygen exposure time and burial for

  15. AECB workshop on seismic hazard assessment in Southern Ontario. Recorded proceedings

    International Nuclear Information System (INIS)

    A workshop on seismic hazard assessment in southern Ontario was conducted on June 19-21, 1995. The purpose of the workshop was to review available geological and seismological data which could affect earthquake occurrence in southern Ontario and to develop a consensus on approaches that should be adopted for characterization of seismic hazard. The workshop was structured in technical sessions to focus presentations and discussions on four technical issues relevant to seismic hazard in southern Ontario, as follows: The importance of geological and geophysical observations for the determination of seismic sources; Methods and approaches which may be adopted for determining seismic sources based on integrated interpretations of geological and seismological information. Methods and data which should be used for characterizing the seismicity parameters of seismic sources. Methods for assessment of vibratory ground motion hazard. This document presents transcripts from recordings made of the presentations and discussion from the workshop. It will be noted, in some sections of the document, that the record is incomplete. This is due in part to recording equipment malfunction and in part due to the poor quality of recording obtained for certain periods

  16. Distribution of Gull Specific Molecular Marker in Coastal Areas of Lake Ontario

    Science.gov (United States)

    Gulls have been implicated as primary sources of fecal contamination in the Great Lakes, a fact that may have health implications due to the potential spread of microbial pathogens by waterfowl. To better understand the spatial variability of gull fecal contamination, a gull-spe...

  17. ECOLOGICAL RISKS OF DIOXINS IN LAKE ONTARIO: A TALE OF TWO CORES

    Science.gov (United States)

    Sediment box cores have frequently been used to determine organochlorine chemical loading histories of lakes and reservoirs. ? Typical profiles for PCBs or DDT show concentrations that increase from around 1940 to 1970 and then decline to the present. Applying these data to retr...

  18. An investigation of roof runoff during rain events at the Royal Military College of Canada and potential discharge to Lake Ontario.

    Science.gov (United States)

    Kelly, David G; Weir, Ron D; White, Steven D

    2011-01-01

    The Royal Military College of Canada, located on the north eastern shore of Lake Ontario, possesses an abundance of copper roofs and lacks surface water treatment prior to discharge into Lake Ontario. Rainwater, roof runoff and soil samples were collected and analyzed for copper and other parameters. Copper was consistently detected in runoff samples with average concentrations of 3200 +/- 2100 microg/L. Multivariable linear regression analysis for a dependant copper runoff concentration yielded an adjusted R2 value of 0.611, based on an independent variable model using minimum temperature, maximum temperature, total precipitation, and wind speed. Lake water samples taken in the vicinity of storm water outfalls draining areas with copper roofs ranged from 2.0 to 40 microg/L copper. Such data exceed the 2.0 microg/L Canadian Water Quality Guidelines for the Protection of Aquatic Life as outlined by the Canadian Council of Ministers of the Environment (CCME). Analysis of raw, filtered and digested forms suggested that the majority of copper present in runoff and lake water samples was in a dissolved form. The majority of soils taken in this study displayed copper concentrations below the 63 microg/g CCME residential/parkland land use limits. These findings suggested that ion exchange processes between runoff water and soil do not occur to a sufficient extent to elevate copper levels in soil. It may therefore be concluded that the eventual fate of copper, which is not discharged via storm water outfalls, is lost to the water table and Lake Ontario through the sub-soil. PMID:22125898

  19. Impacts of changing food webs in Lake Ontario: Implications of dietary fatty acids on growth of alewives

    Science.gov (United States)

    Snyder, R.J.; Demarche, C.J.; Honeyfield, D.C.

    2011-01-01

    Declines in the abundance and condition of Great Lakes Alewives have been reported periodically during the last two decades, and the reasons for these declines remain unclear. To better understand how food web changes may influence Alewife growth and Wisconsin growth model predictions, we fed Alewives isocaloric diets high in omega-6 fatty acids (corn oil) or high in omega-3 fatty acids (fish oil). Alewives were fed the experimental diets at either 1% ("low ration") or 3% ("high ration") of their wet body weight per day. After six weeks, Alewives maintained on the high ration diets were significantly larger than those fed the low ration diets. Moreover, Alewives given the high ration fish oil diet were significantly larger than those maintained on the high ration corn oil diet after six weeks of growth. Body lipid, energy density and total body energy of Alewives on the high ration diets were significantly higher than those fed the low ration diets, and total body energy was significantly higher in Alewives given the high ration fish oil diet compared to those on the high ration corn oil diet. The current Wisconsin bioenergetics model underestimated growth and overestimated food consumption by Alewives in our study. Alewife thiaminase activity was similar among treatment groups. Overall, our results suggest that future food web changes in Lake Ontario, particularly if they involve decreases in the abundance of lipid rich prey items such as Mysis, may reduce Alewife growth rates and total body energy due to reductions in the availability of dietary omega-3 fatty acids. ?? 2011 AEHMS.

  20. Application of neural networks to prediction of fish diversity and salmonid production in the Lake Ontario basin

    Science.gov (United States)

    McKenna, James E.

    2005-01-01

    Diversity and fish productivity are important measures of the health and status of aquatic systems. Being able to predict the values of these indices as a function of environmental variables would be valuable to management. Diversity and productivity have been related to environmental conditions by multiple linear regression and discriminant analysis, but such methods have several shortcomings. In an effort to predict fish species diversity and estimate salmonid production for streams in the eastern basin of Lake Ontario, I constructed neural networks and trained them on a data set containing abiotic information and either fish diversity or juvenile salmonid abundance. Twenty percent of the original data were retained as a test data set and used in the training. The ability to extend these neural networks to conditions throughout the streams was tested with data not involved in the network training. The resulting neural networks were able to predict the number of salmonids with more than 84% accuracy and diversity with more than 73% accuracy, which was far superior to the performance of multiple regression. The networks also identified the environmental variables with the greatest predictive power, namely, those describing water movement, stream size, and water chemistry. Thirteen input variables were used to predict diversity and 17 to predict salmonid abundance.

  1. Dissecting the spatial scales of mercury accumulation in Ontario lake sediment

    International Nuclear Information System (INIS)

    Total mercury concentration was analyzed in 171 lakes from pre-industrial (>30 cm depth; Hgpre-industrial) and present-day sediments (0.5-1 cm; Hgpresent-day). Numerous hot or cold spots of sediment mercury enrichment (Hg EF; Hgpre-industrial/Hgpresent-day) were evident as determined by local tests of autocorrelation, although in most cases, the maximum correlation among sites was not the nearest neighbor, indicating a strong influence of watershed characteristics. Hg EF was correlated with the area of open water (ha) (r = 0.91, p = 0.035), mine tailings (r = 0.94, p = 0.019), and organic deposits in surficial geology of the watershed (r = -0.91, p = 0.034). Through use of local rather than global regression coefficients, R2 increased from 0.20 (p = 0.005) to 0.60 (p = 0.013). A broad spatial pattern (>500 km) observed only in Hgpre-industrial was best explained by mean annual precipitation (shared variance = 3.5%), while finer spatial patterns only observed in Hgpresent-day and Hg EF were best explained by pH (average shared variance = 10.8%). - Present mercury accumulation in lake sediment occurs on finer spatial gradients than found pre-industrially, these new spatial gradients correlate well with gradients in lake pH.

  2. Survey of Lake Ontario bottom sediment off Rochester, New York, to define the extent of jettisoned World War II material and its potential for sediment contamination

    Science.gov (United States)

    Kennedy, Gregory; Kappel, William M.

    2000-01-01

    Military-type mat??riel was recovered from the bottom of Lake Ontario near Rochester, N.Y., during bottom-trawl, fish-stock surveys at depths of 75 to 180 feet each year from 1978 through 1996. The recovered mat??riel included many shell-detonator nose cones (2 inches in diameter by about 3.5 inches long); several electronic components; one corroded box of detonators; a corrugated container of mercury-filled capsules; and corroded batteries. Most of the recovered mat??riel has been identified as defective components of shell detonators (proximity-fuze assemblies) that were jettisoned in the lake to protect them from discovery during World War II. Side-scan SONAR, metal-detector, and ROV (remotely-operated-vehicle) surveys found no evidence of any large piles of mat??riel containing potentially hazardous, toxic, or polluting materials within the 17-square-mile study site. Many scattered magnetic anomalies were detected in this area, but chemical analysis of bottom sediment and of zebra- and quagga-mussel (Dreissena spp.) tissue indicate that the concentrations of mercury and other heavy metals are within the previously documented ranges for Lake Ontario sediment. The failure of ROV videos and of SCUBA-diver surveys and probes of the lake bottom to locate any debris indicates that most, if not all, of the debris is scattered and buried under a layer of fine-grained sediment and, possibly, mussels.

  3. Scaled-chrysophyte assemblage changes in the sediment records of lakes recovering from marked acidification and metal contamination near Wawa, Ontario, Canada

    Directory of Open Access Journals (Sweden)

    John P. Smol

    2012-07-01

    Full Text Available A remarkable example of point-source lake acidification and metal pollution, and subsequent recovery in limnological variables, has occurred in lakes near the former iron sintering plant at Wawa (Ontario, Canada. Surface water pH levels in some of these lakes have increased from 3 to 7 following local sulphur emission reductions with closure of industrial operations. Previous paleolimnological work documented striking successional changes in diatom species assemblages within dated sediment cores that could be related to past industrial activities. To gain additional insights into the chemical and biological recovery trajectories of the Wawa lakes, we used paleolimnological techniques to track euplanktonic scaled-chrysophyte (classes Chrysophyceae and Synurophyceae species assemblage responses to historical water quality changes in five lakes. Coincident with the period of iron sintering from 1939 to 1998, striking successional changes were noted in the sedimentary profiles, with marked increases in the relative abundances of the acid- and metal-tolerant taxon Synura echinulata. The scaled chrysophyte changes pre-dated diatom responses, confirming the former’s status as reliable early warning indicators of lake acidification. Following closure of the sintering plant, species-specific chrysophyte responses to decreased emissions varied amongst the study lakes, perhaps reflecting differences in local bedrock geology and hydrological regime. Although some water chemistry variables may have recovered to near pre-industrial levels, similar to the diatom study, our data show that chrysophyte assemblages in the most recent sediments are now significantly different from pre-industrial assemblages.

  4. Origin of Archean anorthosites - Evidence from the Bad Vermilion Lake anorthosite complex, Ontario

    Science.gov (United States)

    Ashwal, L. D.; Morrison, D. A.; Phinney, W. C.; Wood, J.

    1983-01-01

    Studies of the petrology and geochemistry of the anorthosite complex at Bad Vermillion Lake, Canada, based on 400 samples collected in summer, 1979, are presented. Petrographic, microprobe, X-ray-fluorescence, and instrumental-neutron-activation analyses were performed. Major and trace-element abundances of the anorthositic rocks and surrounding mafic and felsic rocks are reported in tables, chondrite-normalized rare-earth-element patterns are shown, and the anorthositic, intrusive, and metavolcanic formations are characterized in detail. The anothrositic plagioclases are found to have a coarse porphyritic texture and calcic composition (80 normative mol percent An) similar to those of other Archean anorthosite complexes. Chemical similarities indicate that the gabbro and mafic to felsic metavolcanic formations associated with the anorthosite complex may be comagmatic with it, while the absence of ultramafic material and the bulk composition of the comagmatic basalt (about 20 wt percent Al2O3) suggest that much of the original comagmatic material has been separated.

  5. Age and origin of uraninite in the Elliot Lake, Ontario uranium ores

    International Nuclear Information System (INIS)

    There is a strong, positive linear correlation between the 204Pb/206Pb and 207Pb/206Pb ratios and between the 208Pb/206Pb and 207Pb/206Pb ratios in the galenas. The linear relation is interpreted to be the result of ''mixing'' of isotopically distinct Pb produced during two uraninite Pb loss episodes. A complete mixing of crustal Pb and radiogenic Pb released from the associated uraninite at a time T1 formed one end member of the observed trends. The other end member consists of radiogenic Pb released from the uraninite at a later time T2. The galena Pb isotope data indicate that T0, the inital age of the uraninite in the Elliot Lake ores, is 2200-3300 Ma, T1 is less than 2200 Ma, and T2 is less than 1350 Ma. Upper concordia intercepts for most uraninite grains range from 2210 +/- 430 Ma to 2575 +/- 180 Ma; lower concordia intercepts range from 1200 +/- 120 Ma to 1705 +/- 30 Ma. During the first Pb loss episode, at time T1, the centers of most uraninite grains released 45-90% of the accumulated Pb and the outer 5 μm region of the grains released 95-100% of the accumulated Pb. During the second Pb loss episode, at time T2, the grain exteriors released 2-6 times more Pb than the grain centers. A few highly fractured grains appear to have been ''reset'' at T1. The uraninite U-Pb data indicate that T0 greater than or equal to 1700 Ma. Together, the galena Pb isotope and uraninite U-Pb data require that T0 = 2560 +/- 50 Ma, T1, = 1700 +/- 50 Ma, and T2 = 500 +/- 180 Ma, if the 2350 +/- 100 Ma estimated age of deposition of the Huronian rocks (Roscoe, 1973) is correct, the 2560 +/- Ma obtained for the uraninite requires that the uraninite in the Elliot Lake ores is of detrital derivation

  6. Assessing access for prospective adoptive parents living with HIV: an environmental scan of Ontario's adoption agencies.

    Science.gov (United States)

    Underhill, Angela A; Kennedy, V Logan; Lewis, Johanna; Ross, Lori E; Loutfy, Mona

    2016-10-01

    Work has been underway to increase the availability of parenting options for people living with and affected by HIV. One option, adoption, has not yet been explored in the literature. The study aimed to gain a better understanding of the potential of adoption for individuals/couples living with HIV in Ontario, and to assess potential structural barriers or facilitators that may impact their experience navigating the adoption system by conducting an environmental scan of adoption service providers in Ontario. A list of adoption service providers was compiled using the Ontario government's website. Information relevant to the study's measures was collected using service providers' websites. Service providers without websites, or with websites that did not address all of the research measures, were contacted via telephone to complete a structured interview. Online data extraction was possible for 2 and telephone surveys were completed with 75 adoption service providers (total n = 77). Most service providers reported that HIV status is not an exclusion criterion for prospective parents (64%). However, more than one-fifth of the participants acknowledged they were not sure if people with HIV were eligible to adopt. Domestic service providers were the only providers who did not report knowledge of restrictions due to HIV status. Private domestic adoption presented social barriers as birth parent(s) of a child can access health records of a prospective parent and base their selection of an adoptive parent based on health status. Adoption practitioners and licensees involved in international adoptions reported the most structural barriers for prospective parent(s) living with HIV, attributed to the regulations established by the host country of the child(ren) eligible for adoption. Although international adoptions may present insurmountable barriers for individuals living with HIV, public and private domestic adoption appears to be a viable option. PMID:27136971

  7. Count trends for migratory Bald Eagles reveal differences between two populations at a spring site along the Lake Ontario shoreline.

    Science.gov (United States)

    Wright, Kyle R

    2016-01-01

    The recovery of Bald Eagles (Haliaeetus leucophalus), after DDT and other organochlorine insecticides were banned in the United States, can be regarded as one of the most iconic success stories resulting from the Endangered Species Act. Interest remains high in the recovery and growth of the Bald Eagle population. Common to evaluating growth and recovery rates are counts at nesting sites and analyses of individuals fledged per season. But this is merely one snapshot that ignores survival rates as eagles grow to maturity. By analyzing indices from migration counts, we get a different snapshot better reflecting the survival of young birds. Different populations of Bald Eagles breed at different sites at different times of the year. Typical migration count analyses do not separate the populations. A separation of two distinct populations can be achieved at spring count sites by taking advantage of the tendency for northern summer breeding birds to migrate north in spring earlier than southern winter breeding birds who disperse north later in spring. In this paper I analyze migratory indices at a spring site along Lake Ontario. The analysis shows that eagles considered to be primarily of the northern summer breeding population showed an estimated growth rate of 5.3 ± 0.85% (SE) per year with 49% of eagles tallied in adult plumage, whereas the migrants considered to be primarily of the southern breeding population had an estimated growth rate of 14.0 ± 1.79% with only 22% in adult plumage. Together these results argue that the populations of southern breeding Bald Eagles are growing at a substantially higher rate than northern breeding eagles. These findings suggest that aggregate population indices for a species at migration counting sites can sometimes obscure important differences among separate populations at any given site and that separating counts by time period can be a useful way to check for differences among sub-populations. PMID:27231647

  8. Predicting wetland plant community responses to proposed water-level-regulation plans for Lake Ontario: GIS-based modeling

    Science.gov (United States)

    Wilcox, D.A.; Xie, Y.

    2007-01-01

    Integrated, GIS-based, wetland predictive models were constructed to assist in predicting the responses of wetland plant communities to proposed new water-level regulation plans for Lake Ontario. The modeling exercise consisted of four major components: 1) building individual site wetland geometric models; 2) constructing generalized wetland geometric models representing specific types of wetlands (rectangle model for drowned river mouth wetlands, half ring model for open embayment wetlands, half ellipse model for protected embayment wetlands, and ellipse model for barrier beach wetlands); 3) assigning wetland plant profiles to the generalized wetland geometric models that identify associations between past flooding / dewatering events and the regulated water-level changes of a proposed water-level-regulation plan; and 4) predicting relevant proportions of wetland plant communities and the time durations during which they would be affected under proposed regulation plans. Based on this conceptual foundation, the predictive models were constructed using bathymetric and topographic wetland models and technical procedures operating on the platform of ArcGIS. An example of the model processes and outputs for the drowned river mouth wetland model using a test regulation plan illustrates the four components and, when compared against other test regulation plans, provided results that met ecological expectations. The model results were also compared to independent data collected by photointerpretation. Although data collections were not directly comparable, the predicted extent of meadow marsh in years in which photographs were taken was significantly correlated with extent of mapped meadow marsh in all but barrier beach wetlands. The predictive model for wetland plant communities provided valuable input into International Joint Commission deliberations on new regulation plans and was also incorporated into faunal predictive models used for that purpose.

  9. Count trends for migratory Bald Eagles reveal differences between two populations at a spring site along the Lake Ontario shoreline

    Science.gov (United States)

    2016-01-01

    The recovery of Bald Eagles (Haliaeetus leucophalus), after DDT and other organochlorine insecticides were banned in the United States, can be regarded as one of the most iconic success stories resulting from the Endangered Species Act. Interest remains high in the recovery and growth of the Bald Eagle population. Common to evaluating growth and recovery rates are counts at nesting sites and analyses of individuals fledged per season. But this is merely one snapshot that ignores survival rates as eagles grow to maturity. By analyzing indices from migration counts, we get a different snapshot better reflecting the survival of young birds. Different populations of Bald Eagles breed at different sites at different times of the year. Typical migration count analyses do not separate the populations. A separation of two distinct populations can be achieved at spring count sites by taking advantage of the tendency for northern summer breeding birds to migrate north in spring earlier than southern winter breeding birds who disperse north later in spring. In this paper I analyze migratory indices at a spring site along Lake Ontario. The analysis shows that eagles considered to be primarily of the northern summer breeding population showed an estimated growth rate of 5.3 ± 0.85% (SE) per year with 49% of eagles tallied in adult plumage, whereas the migrants considered to be primarily of the southern breeding population had an estimated growth rate of 14.0 ± 1.79% with only 22% in adult plumage. Together these results argue that the populations of southern breeding Bald Eagles are growing at a substantially higher rate than northern breeding eagles. These findings suggest that aggregate population indices for a species at migration counting sites can sometimes obscure important differences among separate populations at any given site and that separating counts by time period can be a useful way to check for differences among sub-populations. PMID:27231647

  10. Petrogenesis of orbicular ijolites from the Prairie Lake complex, Marathon, Ontario: Textural evidence from rare processes of carbonatitic magmatism

    Science.gov (United States)

    Zurevinski, Shannon E.; Mitchell, Roger H.

    2015-12-01

    A unique occurrence of orbicular ijolite is hosted in a matrix of contemporaneous holocrystalline ijolite at the 1.1 Ga Prairie Lake Carbonatite Complex (Marathon, Ontario, Canada), and is the only known occurrence of this textural type in a rock of ijolitic composition. This mineralogical and petrological study of this orbicular ijolite highlights many of the differences from other rare occurrences of orbicular rocks described from carbonatites, granites, diorites and lamprophyres. The orbicules occur along distinct, densely packed bands in equigranular nepheline-rich ijolite and range up to 6 cm in diameter. Macroscopically, the orbicules show variability in the mineralogy of their cores. Detailed imaging of the cores shows evidence of quench textures. Radial outward zoning is common near the cores with concentric banding occurring toward the margins of the orbicules. The mineralogy of the orbicules consists of: nepheline; diopside; calcite; apatite; andradite-melanite garnet; titanite; Fe-rich phlogopite; titaniferous magnetite; perovskite; with secondary natrolite, calcite and cancrinite. The mineralogy of the host ijolite is similar to that of the orbicules. Mineral compositions from the orbicular ijolite and the host ijolite are similar. Within the orbicules, anhedral minerals are found occurring in a 'matrix' of garnet throughout the distinct concentric bands. The textures within the concentric bands of the orbicules are best described as annealing recrystallization textures. The rims of the orbicules form interlocking crystals with the host ijolite resulting in near-indistinguishable boundaries. The orbicules are interpreted to represent interaction of a partially-crystallized quenched ijolitic melt, which was in contact with a second pulse of consanguineous ijolite magma. Immersion in the latter resulted in sub-solidus diffusion and annealing recrystallization. Orbicular textures were produced from previously formed quenched ijolite, which was

  11. Age and origin of uraninite in the Elliot Lake, Ontario uranium ores

    Energy Technology Data Exchange (ETDEWEB)

    Meddaugh, W.S.

    1983-01-01

    There is a strong, positive linear correlation between the /sup 204/Pb//sup 206/Pb and /sup 207/Pb//sup 206/Pb ratios and between the /sup 208/Pb//sup 206/Pb and /sup 207/Pb//sup 206/Pb ratios in the galenas. The linear relation is interpreted to be the result of ''mixing'' of isotopically distinct Pb produced during two uraninite Pb loss episodes. A complete mixing of crustal Pb and radiogenic Pb released from the associated uraninite at a time T/sub 1/ formed one end member of the observed trends. The other end member consists of radiogenic Pb released from the uraninite at a later time T/sub 2/. The galena Pb isotope data indicate that T/sub 0/, the inital age of the uraninite in the Elliot Lake ores, is 2200-3300 Ma, T/sub 1/ is less than 2200 Ma, and T/sub 2/ is less than 1350 Ma. Upper concordia intercepts for most uraninite grains range from 2210 +/- 430 Ma to 2575 +/- 180 Ma; lower concordia intercepts range from 1200 +/- 120 Ma to 1705 +/- 30 Ma. During the first Pb loss episode, at time T/sub 1/, the centers of most uraninite grains released 45-90% of the accumulated Pb and the outer 5 ..mu..m region of the grains released 95-100% of the accumulated Pb. During the second Pb loss episode, at time T/sub 2/, the grain exteriors released 2-6 times more Pb than the grain centers. A few highly fractured grains appear to have been ''reset'' at T/sub 1/. The uraninite U-Pb data indicate that T/sub 0/ greater than or equal to 1700 Ma. Together, the galena Pb isotope and uraninite U-Pb data require that T/sub 0/ = 2560 +/- 50 Ma, T/sub 1/, = 1700 +/- 50 Ma, and T/sub 2/ = 500 +/- 180 Ma, if the 2350 +/- 100 Ma estimated age of deposition of the Huronian rocks (Roscoe, 1973) is correct, the 2560 +/- Ma obtained for the uraninite requires that the uraninite in the Elliot Lake ores is of detrital derivation.

  12. Dissecting the spatial scales of mercury accumulation in Ontario lake sediment.

    Science.gov (United States)

    Mills, R Brad; Paterson, Andrew M; Lean, David R S; Smol, John P; Mierle, Greg; Blais, Jules M

    2009-11-01

    Total mercury concentration was analyzed in 171 lakes from pre-industrial (>30 cm depth; Hg(pre-industrial)) and present-day sediments (0.5-1 cm; Hg(present-day)). Numerous hot or cold spots of sediment mercury enrichment (Hg EF; Hg(pre-industrial)/Hg(present-day)) were evident as determined by local tests of autocorrelation, although in most cases, the maximum correlation among sites was not the nearest neighbor, indicating a strong influence of watershed characteristics. Hg EF was correlated with the area of open water (ha) (r = 0.91, p = 0.035), mine tailings (r = 0.94, p = 0.019), and organic deposits in surficial geology of the watershed (r = -0.91, p = 0.034). Through use of local rather than global regression coefficients, R(2) increased from 0.20 (p = 0.005) to 0.60 (p = 0.013). A broad spatial pattern (>500 km) observed only in Hg(pre-industrial) was best explained by mean annual precipitation (shared variance = 3.5%), while finer spatial patterns only observed in Hg(present-day) and Hg EF were best explained by pH (average shared variance = 10.8%). PMID:19577830

  13. Radionuclide uptake by various plants growing on uranium tailings, Elliot Lake, Ontario

    International Nuclear Information System (INIS)

    Detectable levels of Ra-226 (0.2 to 27.6 pCi/g), Ra-223 (<= 0.1 to 4.3 pCi/g) and Pb-210 (0.6 to 6.9 pCi/g) were measured in various species of vegetation growing on various uranium tailings in Elliot Lake. On the other hand levels of Th-232 (<= 0.1 pCi/g), Th-230 (<= 0.1 pCi/g) were near detection limits in the same vegetation samples. In tailings substrates, all radionuclides investigated were detectable: Ra-226 (8.8 to 552 pCi/g), Ra-223 (3.1 to 213 pCi/g), Pb-210 (5.4 to 441 pCi/g), Th-232 (1.6 to 15.4 pCi/g), Th-230 (4.9 to 62 pCi/g) and Th-228 (1.3 to 38 pCi/g). Lower Th than Ra and Pb levels in tailings substrate were believed to be the cause for the relatively lower Th levels measured in vegetation when compared to Ra and Pb concentrations. No correlation was observed between the level of a given radionuclide in tailings and in the vegetation growing on that tailings

  14. The geochemistry, age, and origin of groundwater in a mafic pluton, East Bull Lake, Ontario, Canada

    International Nuclear Information System (INIS)

    Atomic Energy of Canada Ltd. (AECL) is conducting geoscience investigations of several plutons in Canada's Precambrian Shield as part of the Canadian Nuclear Fuel Waste Management Program, to determine whether such rock masses are suitable for the safe disposal of nuclear fuel waste. The East Bull Lake (EBL) gabbro-anorthosite layered complex is unique in this program as it is the only mafic pluton in which hydrogeological and hydrogeochemical studies have been conducted. These results can be compared with those of similar studies of granitic rocks which have been investigated more extensively. During the period, 1983-85, hydrogeological testing and hydrochemical sampling were conducted by the National Hydrology Research Institute of Environment Canada and AECL in boreholes drilled to depths of up to 850 m into the EBL pluton (Raven et al., 1987). This paper discusses the hydrogeochemistry of the pluton and identifies the major rock-water interactions controlling the chemistry. The spatial variability in chemistry will be shown to be related to the nature of the groundwater flow systems present at this site. The ages and origins of the groundwaters and their solutes are inferred from isotopic analyses

  15. AECB workshop on seismic hazard assessment in Southern Ontario. Program, list of participants and abstracts

    International Nuclear Information System (INIS)

    The purpose of the workshop was to review available geological and seismological data which could affect earthquake occurrence in southern Ontario and to develop a consensus on approaches that should be adopted for characterization of seismic hazard. The workshop was structured in technical sessions to focus presentations and discussions on four technical issues relevant to seismic hazard in southern Ontario, as follows: (1) The importance of geological and geophysical observations for the determination of seismic sources, (2) Methods and approaches which may be adopted for determining seismic sources based on integrated interpretations of geological and seismological information, (3) Methods and data which should be used for characterizing the seismicity parameters of seismic sources, and (4) Methods for assessment of vibratory ground motion hazard. This document presents a copy of the workshop program, the list of participants and extended abstracts received from speakers. It was distributed to the participants prior to the workshop. The abstracts were intended to provide advance information and to afford some basis for meaningful discussion and exchange of information

  16. 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

    The purpose of this project was to conduct the first comprehensive offshore wind assessment over Lake Michigan and to advance the body of knowledge needed to support future commercial wind energy development on the Great Lakes. The project involved evaluation and selection of emerging wind measurement technology and the permitting, installation and operation of the first mid-lake wind assessment meteorological (MET) facilities in Michigan’s Great Lakes. In addition, the project provided the first opportunity to deploy and field test floating LIDAR and Laser Wind Sensor (LWS) technology, and important research related equipment key to the sitting and permitting of future offshore wind energy development in accordance with public participation guidelines established by the Michigan Great Lakes Wind Council (GLOW). The project created opportunities for public dialogue and community education about offshore wind resource management and continued the dialogue to foster Great Lake wind resource utilization consistent with the focus of the GLOW Council. The technology proved to be effective, affordable, mobile, and the methods of data measurement accurate. The public benefited from a substantial increase in knowledge of the wind resources over Lake Michigan and gained insights about the potential environmental impacts of offshore wind turbine placements in the future. The unique first ever hub height wind resource assessment using LWS technology over water and development of related research data along with the permitting, sitting, and deployment of the WindSentinel MET buoy has captured public attention and has helped to increase awareness of the potential of future offshore wind energy development on the Great Lakes. Specifically, this project supported the acquisition and operation of a WindSentinel (WS) MET wind assessment buoy, and associated research for 549 days over multiple years at three locations on Lake Michigan. Four research objectives were defined for the

  17. The application of resilience assessment - resilience of what, to what, with what? A case study based on Caledon, Ontario, Canada

    OpenAIRE

    Wai Ting Liu

    2014-01-01

    Resilience assessment can be used to determine major issues, stakeholders, vulnerabilities, and opportunities of a social-ecological system to enhance resilience. A resilience assessment was conducted on the Town of Caledon, Ontario between 2010 and 2011 using the Resilience Assessment Workbook for Practitioners (version 1). The assessment explores the following three questions: Resilience of what? Resilience to what? Resilience with what? The answer to the first question describes the histor...

  18. First detection and confirmation of spring viraemia of carp virus in common carp, Cyprinus carpio L., from Hamilton Harbour, Lake Ontario, Canada.

    Science.gov (United States)

    Garver, K A; Dwilow, A G; Richard, J; Booth, T F; Beniac, D R; Souter, B W

    2007-11-01

    In June 2006, 150 wild common carp were sampled from Hamilton Harbour, Lake Ontario, Canada. Tissue pools consisting of kidney, spleen and encephalon were screened for viruses as a condition facilitating the export of live carp to France. Cytopathic effect (CPE), indicative of a viral infection, became evident after 8 days of incubation at 15 degrees C. Eighteen of 30 tissue pools (five fish per pool) eventually demonstrated viral CPE. The viral pathogen was initially cultured and isolated on the epithelioma papulosum cyprini cell line and subsequently shown to produce CPE in the fathead minnow and bluegill fin cell lines. Electron microscopy demonstrated the virus to be a rhabdovirus. Reverse transcriptase-polymerase chain reaction assay and nucleotide sequence analysis identified the isolate as spring viraemia of carp virus (SVCV). Phylogenetic analysis of a 533 bp region of the glycoprotein gene grouped the Canadian isolate in SVCV genogroup Ia together with isolates from Asia and the USA. Sequence comparisons revealed the Hamilton Harbour, Lake Ontario isolate to be most similar to an isolate obtained from common carp in the Calumet Sag Channel in Illinois in 2003 (98.9% nucleotide identity). This is the first report of the detection of SVCV in Canada. PMID:17958610

  19. The impacts of future climate change and sulphur emission reductions on acidification recovery at Plastic Lake, Ontario

    Directory of Open Access Journals (Sweden)

    J. Aherne

    2008-03-01

    Full Text Available Climate-induced drought events have a significant influence on sulphate export from forested catchments in central Ontario, subsequently delaying the recovery of surface waters from acidification. In the current study, a model chain that employed a statistical downscaling model, a hydrological model and two hydrochemical models was used to forecast the chemical recovery of Plastic Lake sub-catchment 1 (PC1 from acidification under proposed deposition reductions and the A2 emission scenario of the Intergovernmental Panel on Climate Change. Any predicted recovery in stream acid neutralising capacity and pH owing to deposition reductions were clearly offset by large acid effluxes from climate-induced drought events. By 2100, ANC is predicted to show large variations ranging between 10 and −30 μmolc L−1. Similarly, predicted pH in 2100 is lower (>0.05 of a pH unit than the value simulated for 2000 (pH 4.35. Despite emission reductions, the future scenario paints a bleak picture of reacidification at PC1 to levels commensurate with those of the late 1970s. The principal process behind this reacidification is the oxidation of previously stored (reduced sulphur compounds in wetlands during periods of low-flow (or drought, with subsequent efflux of sulphate upon re-wetting. Simulated catchment runoff under the A2 emissions scenario predictes increased intensity and frequency of low-flow events from approximately 2030 onwards. The Integrated Catchments model for Carbon indicated that stream DOC concentrations at PC1 will also increase under the future climate scenario, with temperature being the principal driver. Despite the predicted (significant increase in DOC, pH is not predicted to further decline (beyond the climate-induced oxidation scenario, instead pH shows greater variability throughout the simulation. As echoed by many recent studies, hydrochemical models and model frameworks need to incorporate the drivers

  20. Conflict Management in Participatory Approaches to Water Management: A Case Study of Lake Ontario and the St. Lawrence River Regulation

    Directory of Open Access Journals (Sweden)

    Alison Furber

    2016-07-01

    Full Text Available The International Joint Commission (IJC has been involved in a 14-year effort to formulate a new water regulation plan for the Lake Ontario St. Lawrence River (“LOSLR” area that balances the interests of a diverse group of stakeholders including shipping and navigation, hydropower, environment, recreational boating, municipal and domestic water supply, First Nations, and shoreline property owners. It has embraced the principles of collaborative and participatory management and, applying a Shared Visioning Planning (SVP approach, has worked closely with stakeholders throughout all stages of this process; however, conflicts between competing stakeholders have delayed and complicated this effort. The overarching aim of this paper is to consider the extent to which the SVP approach employed by the IJC was effective in managing conflict in the LOSLR context. Audio recordings and transcriptions of public and technical hearings held by the IJC in 2013 have been systematically analysed using stakeholder mapping and content analysis methods, to gain insight into the stakeholder universe interacting with the IJC on Plan 2014.  The principal conclusions of this paper are that (a the Shared Vision Planning approach employed by the IJC had some significant successes in terms of conflict management—particularly notable is the success that has been achieved with regards to integration of First Nation concerns; (b there is a distinct group of shoreline property owners, based in New York State, who remain opposed to Plan 2014—the IJC’s public outreach and participation efforts have not been successful in reconciling their position with that of other stakeholders due to the fact that this stakeholder group perceive that they can only lose out from any regulation change and are therefore unlikely to be motivated to engage productively in any planning dialogue; and (c a solution would require that the problem be reframed so that this stakeholder can see

  1. The impacts of future climate change and sulphur emission reductions on acidification recovery at Plastic Lake, Ontario

    Directory of Open Access Journals (Sweden)

    J. Aherne

    2007-09-01

    Full Text Available Climate-induced drought events have a significant influence on sulphate export from forested catchments in central Ontario, subsequently delaying the recovery of surface waters from acidification. In the current study, a model chain that employed a statistical downscaling model, a hydrological model and two hydrochemical models was used to forecast the chemical recovery of Plastic Lake sub-catchment 1 (PC1 from acidification under proposed deposition reductions and the A2 emission scenario of the Intergovernmental Panel on Climate Change. Any predicted recovery in stream acid neutralising capacity and pH owing to deposition reductions were clearly offset by large acid effluxes from climate-induced drought events. By 2100, ANC is predicted to show large variations ranging between 10 and −30 μmolc L−1. Similarly, predicted pH in 2100 is lower (>0.05 of a pH unit than the value simulated for 2000 (pH 4.35. Despite emission reductions, the future scenario paints a bleak picture of reacidification at PC1 to levels commensurate with those of the late 1970s. The principal process behind this reacidification is the oxidation of previously stored (reduced sulphur compounds in wetlands during periods of low-flow (or drought, with subsequent efflux of sulphate upon re-wetting. Simulated catchment runoff under the A2 emissions scenario predictes increased intensity and frequency of low-flow events from approximately 2030 onwards. The Integrated Catchments model for Carbon indicated that stream DOC concentrations at PC1 will also increase under the future climate scenario, with temperature being the principal driver. Despite the predicted (significant increase in DOC, pH is not predicted to further decline (beyond the climate-induced oxidation scenario, instead pH shows greater variability throughout the simulation. As echoed by many recent studies, hydrochemical models and model frameworks need to incorporate the drivers

  2. Environmental Assessment: Submerged Aquatic Plant Management of Banks Lake, Banks Lake NWR, Lakeland, Georgia

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Environmental Assessment is an analysis of five alternatives developed to address themanagement of the submerged aquatic plants of Banks Lake on Banks Lake...

  3. 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

    The purpose of this project was to conduct the first comprehensive offshore wind assessment over Lake Michigan and to advance the body of knowledge needed to support future commercial wind energy development on the Great Lakes. The project involved evaluation and selection of emerging wind measurement technology and the permitting, installation and operation of the first mid-lake wind assessment meteorological (MET) facilities in Michigan’s Great Lakes. In addition, the project provided the first opportunity to deploy and field test floating LIDAR and Laser Wind Sensor (LWS) technology, and important research related equipment key to the sitting and permitting of future offshore wind energy development in accordance with public participation guidelines established by the Michigan Great Lakes Wind Council (GLOW). The project created opportunities for public dialogue and community education about offshore wind resource management and continued the dialogue to foster Great Lake wind resource utilization consistent with the focus of the GLOW Council. The technology proved to be effective, affordable, mobile, and the methods of data measurement accurate. The public benefited from a substantial increase in knowledge of the wind resources over Lake Michigan and gained insights about the potential environmental impacts of offshore wind turbine placements in the future. The unique first ever hub height wind resource assessment using LWS technology over water and development of related research data along with the permitting, sitting, and deployment of the WindSentinel MET buoy has captured public attention and has helped to increase awareness of the potential of future offshore wind energy development on the Great Lakes. Specifically, this project supported the acquisition and operation of a WindSentinel (WS) MET wind assessment buoy, and associated research for 549 days over multiple years at three locations on Lake Michigan. Four research objectives were defined for the

  4. Assessment of the economic impact of ozone on the agricultural sector in Ontario, Canada

    International Nuclear Information System (INIS)

    Ozone is the most damaging secondary pollutant to agricultural production, according to the literature. It is estimated that 90% of crop losses due to air pollution are caused by ozone. The economic impact of ozone on 20 agricultural commodities in Ontario is assessed in two steps. In the first, ozone contour maps are generated for the province. The results suggest an average ozone concentration of 40 ppB, higher than the natural background of 20 ppB. The second step measures the change in consumer and producer surplus that results from reductions in ozone levels in Ontario from 40 ppB to 20 ppB. Consumer plus producer surpluses correspond to the area below the demand curve and above the supply curve to the left of their intersection. A nonlinear programming model that maximizes consumer and producer surpluses, subject to a set of constraints, was run twice. The first run incorporates realized yields and production costs, and the second incorporates biological yield changes owing to ozone and the associated changes in production costs. The difference in value of the objective functions between the two runs shows the net benefits of reduced ozone levels. Results indicate an average net benefit of $64.3 million/y or 5.8% of the total value of all the crops considered. Average annual consumer benefits are $44.1 million and producer benefits $20.2 million. Not all producers benefit from ozone reductions; producers of fresh vegetables lose while producers of grain corn, soybeans, and winter wheat gain. 54 refs., 6 figs., 15 tabs

  5. Ecosystem Health Assessment in Wuli Lake

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Using the method of trophic state-composite index (TSI-CI ) and the 12 months of monitoring data in 2010,we carry out initial exploration of the status of ecosystem health in Wuli Lake. First,we select four indicators,Chla,SD,TP and TN,to conduct trophic state assessment using weighted index method; then after selecting physical,chemical and biological indicators to conduct nondimensionalization processing,we calculate the composite index and conduct comprehensive assessment. The results show that in 2010,the status of ecosystem health in Wuli Lake was the best in July,worst in August; when the composite trophic state indicators with Chla as the representative increase or decrease significantly and cross different nutritional grades,TSI will significantly deviate from CI,and the relationship between the two in the other time is not prominent.

  6. Health impact assessment of Ontario's green energy and green economy act. The roles of environmental informatics in sustainability

    Energy Technology Data Exchange (ETDEWEB)

    Rattle, Robert

    2013-07-01

    Renewable energy received a boost in Ontario, Canada with the Green Energy and Green Economy Act (GEGEA), ushering in a new Feed-in-Tariff (FIT) program modelled on programs from Germany, Spain, Denmark and other jurisdictions. Information about lessons learned elsewhere has clearly benefited the Ontario experience. Part of the Ontario program included streamlining the impact assessment process to facilitate the swift development of provincial renewable energy capacities. In this context, the GEGEA has been remarkably successful, generating renewable energy sector capacities, resources, projects and their spin-off benefits in Ontario, along with more sustainable electricity system. Environmentalists along with industry continue to laud the benefits of renewable energy and the GEGEA, and with good reason. Renewable energy generation in Ontario has grown from to 2 per cent in 2012 and is expected to reach 10 per cent in 2013. (orig.)

  7. Evaluation of the Johne's disease risk assessment and management plan on dairy farms in Ontario, Canada.

    Science.gov (United States)

    Pieper, Laura; Sorge, Ulrike S; DeVries, Trevor J; Godkin, Ann; Lissemore, Kerry; Kelton, David F

    2015-10-01

    Johne's disease (JD) is a production-limiting gastrointestinal disease in cattle. To minimize the effects of JD, the Ontario dairy industry launched the Ontario Johne's Education and Management Assistance Program in 2010. As part of the program, trained veterinarians conducted a risk assessment and management plan (RAMP), an on-farm questionnaire where high RAMP scores are associated with high risk of JD transmission. Subsequently, veterinarians recommended farm-specific management practices for JD prevention. Milk or serum ELISA results from the milking herd were used to determine the herd ELISA status (HES) and within-herd prevalence. After 3.5 yr of implementation of the program, the aim of this study was to evaluate the associations among RAMP scores, HES, and recommendations. Data from 2,103 herds were available for the analyses. A zero-inflated negative binomial model for the prediction of the number of ELISA-positive animals per farm was built. The model included individual RAMP questions about purchasing animals in the logistic portion, indicating risks for between-herd transmission, and purchasing bulls, birth of calves outside the designated calving area, colostrum and milk feeding management, and adult cow environmental hygiene in the negative binomial portion, indicating risk factors for within-herd transmission. However, farms which fed low-risk milk compared with milk replacer had fewer seropositive animals. The model additionally included the JD herd history in the negative binomial and the logistic portion, indicating that herds with a JD herd history were more likely to have at least 1 positive animal and to have a higher number of positive animals. Generally, a positive association was noted between RAMP scores and the odds of receiving a recommendation for the respective risk area; however, the relationship was not always linear. For general JD risk and calving area risk, seropositive herds had higher odds of receiving recommendations compared

  8. Evaluation of the Johne's disease risk assessment and management plan on dairy farms in Ontario, Canada.

    Science.gov (United States)

    Pieper, Laura; Sorge, Ulrike S; DeVries, Trevor J; Godkin, Ann; Lissemore, Kerry; Kelton, David F

    2015-10-01

    Johne's disease (JD) is a production-limiting gastrointestinal disease in cattle. To minimize the effects of JD, the Ontario dairy industry launched the Ontario Johne's Education and Management Assistance Program in 2010. As part of the program, trained veterinarians conducted a risk assessment and management plan (RAMP), an on-farm questionnaire where high RAMP scores are associated with high risk of JD transmission. Subsequently, veterinarians recommended farm-specific management practices for JD prevention. Milk or serum ELISA results from the milking herd were used to determine the herd ELISA status (HES) and within-herd prevalence. After 3.5 yr of implementation of the program, the aim of this study was to evaluate the associations among RAMP scores, HES, and recommendations. Data from 2,103 herds were available for the analyses. A zero-inflated negative binomial model for the prediction of the number of ELISA-positive animals per farm was built. The model included individual RAMP questions about purchasing animals in the logistic portion, indicating risks for between-herd transmission, and purchasing bulls, birth of calves outside the designated calving area, colostrum and milk feeding management, and adult cow environmental hygiene in the negative binomial portion, indicating risk factors for within-herd transmission. However, farms which fed low-risk milk compared with milk replacer had fewer seropositive animals. The model additionally included the JD herd history in the negative binomial and the logistic portion, indicating that herds with a JD herd history were more likely to have at least 1 positive animal and to have a higher number of positive animals. Generally, a positive association was noted between RAMP scores and the odds of receiving a recommendation for the respective risk area; however, the relationship was not always linear. For general JD risk and calving area risk, seropositive herds had higher odds of receiving recommendations compared

  9. Wait Times for Sleep Apnea Care in Ontario: A Multidisciplinary Assessment

    OpenAIRE

    Rotenberg, Brian W; George, Charles F.; Sullivan, Kevin M; Eric Wong

    2010-01-01

    BACKGROUND: Obstructive sleep apnea (OSA) is a highly prevalent disorder that is associated with significant patient morbidity and societal burden. In general, wait times for health care in Ontario are believed to be lengthy; however, many diseases lack specific corroborative wait time data.OBJECTIVE: To characterize wait times for OSA care in Ontario.METHODS: Cross-sectional survey. A survey tool was designed and validated to question physicians involved in OSA care about the length of the w...

  10. Development of indicators for assessment of Lake Malawi Basin in an Integrated Lake Basin Management (ILBM) framework

    OpenAIRE

    Clara Limbitso Chidammodzi; Victor Shiholo Muhandiki

    2015-01-01

    This paper sought to understand the current state of the management environment of Lake Malawi Basin, deduce a lake vision and develop indicators for assessing Integrated Lake Basin Management (ILBM) in the lake basin. The premise of the study was that targeted indicators are necessary to effectively monitor the lake basin and manage it sustainably. The study focused on the Malawian side of the lake. Interviews, field observations and review of existing lake management and indicator developme...

  11. How fuel performance is currently assessed for Ontario Power Generation reactors

    International Nuclear Information System (INIS)

    The objective of this paper is to provide an understanding of how current fuel performance is assessed and the results brought into service by the utility. Historically, the main emphasis of fuel assessments was to assess in-bay inspection data and hot-cell examination data to investigate the cause of defect fuel. In recent years, the need to demonstrate that the fuel is operating within its design envelope has necessitated the development of more rigorous inspection plans, techniques, data collection methodologies and analysis tools. Each year an annual fuel performance report is prepared for the CNSC to satisfy a licensing requirement. The main objective of this report is to show that adequate monitoring of the fuel condition is taking place to check that the fuel condition meets the fuel design basis limits. These objectives also serve to give the utility confidence that the fuel condition is monitored and that trends are not leading to adverse operating states that might have large safety / economic impacts. In the late 1990's, the amount of fuel inspection data was becoming large and difficult to manage. It was exceedingly difficult to identify the current fuel condition in the reactors. Information that might be relevant to current on-going problems was difficult to find, and often relied on personal memory. As a result, Ontario Hydro developed a plan to rationalize past data and incorporate the information into a database. Regular collection of fuel inspection data into a database structure, in conjunction with complementary PIE data, allows ongoing mapping and trending of fuel condition in each core. This is used to monitor for precursors of concerns related to operating or manufacturing variance as well as core aging. This is also used to investigate bundle defects cause or operating/handling events. (author)

  12. Streamflow and estimated loads of phosphorus and dissolved and suspended solids from selected tributaries to Lake Ontario, New York, water years 2012–14

    Science.gov (United States)

    Hayhurst, Brett A.; Fisher, Benjamin N.; Reddy, James E.

    2016-07-20

    This report presents results of the evaluation and interpretation of hydrologic and water-quality data collected as part of a cooperative program between the U.S. Geological Survey and the U.S. Environmental Protection Agency. Streamflow, phosphorus, and solids dissolved and suspended in stream water were the focus of monitoring by the U.S. Geological Survey at 10 sites on 9 selected tributaries to Lake Ontario during the period from October 2011 through September 2014. Streamflow yields (flow per unit area) were the highest from the Salmon River Basin due to sustained yields from the Tug Hill aquifer. The Eighteenmile Creek streamflow yields also were high as a result of sustained base flow contributions from a dam just upstream of the U.S. Geological Survey monitoring station at Burt. The lowest streamflow yields were measured in the Honeoye Creek Basin, which reflects a decrease in flow because of withdrawals from Canadice and Hemlock Lakes for the water supply of the City of Rochester. The Eighteenmile Creek and Oak Orchard Creek Basins had relatively high yields due in part to groundwater contributions from the Niagara Escarpment and seasonal releases from the New York State Barge Canal.Annual constituent yields (load per unit area) of suspended solids, phosphorus, orthophosphate, and dissolved solids were computed to assess the relative contributions and allow direct comparison of loads among the monitored basins. High yields of total suspended solids were attributed to agricultural land use in highly erodible soils at all sites. The Genesee River, Irondequoit Creek, and Honeoye Creek had the highest concentrations and largest mean yields of total suspended solids (165 short tons per square mile [t/mi2], 184 t/mi2, and 89.7 t/mi2, respectively) of the study sites.Samples from Eighteenmile Creek, Oak Orchard Creek at Kenyonville, and Irondequoit Creek had the highest concentrations and largest mean yields of phosphorus (0.27 t/mi2, 0.26 t/mi2, and 0.20 t/mi2

  13. Consolidated results of the AECB staff's detailed review of Ontario Hydro Nuclear's integrated independent performance assessment and safety system functional inspection findings

    International Nuclear Information System (INIS)

    In January 1997, Ontario Hydro announced that a team of nuclear industry experts from the United States, called the Nuclear Performance Advisory Group (NPAG), had been employed to help manage its nuclear program and to implement needed improvements in Ontario Hydro Nuclear (OHN) operations. In the spring of 1997, NPAG initiated a series of detailed reviews of OHN's operations, at its Pickering, Bruce and Darlington nuclear generating stations and in OHN's Head Office groups. These reviews, called 'Independent Integrated Performance Assessments' (UPA) and 'Safety System Functional Inspections' (SSFI), were carried out in April and May of this year with the objective of developing 'an integrated, accurate, and comprehensive understanding of the performance of OHN'.They were conducted in response to a request from the President of Ontario Hydro for a 'brutally honest' assessment of Ontario Hydro Nuclear. NPAG has since been integrated into Ontario Hydro's line organization. Ontario Hydro's Board of Directors received the results of the IIPAs and SSFIs and an Ontario Hydro report titled Basis for Continued Operation on August 12, 1997. AECB staff has been reviewing the reports containing these results since receiving them at that time. The conclusions of these studies are extremely critical of the management of Ontario Hydro Nuclear. They identify a large number of shortcomings in the operation and maintenance of the nuclear generating stations. Ontario Hydro states in the IIPA and SSFI reports that the reports are, by design, negative in slant and emphasize the weaknesses in performance rather than the strengths. The reports conclude that the stations can continue to operate safety while the near and long term improvements are implemented. This report contains the consolidated results of the AECB staffs detailed review of the IIPA and SSFI findings. (author)

  14. Detection of viral hemorrhagic septicemia in round gobies in New York State (USA) waters of Lake Ontario and the St. Lawrence River

    Science.gov (United States)

    Groocock, G.H.; Getchell, R.G.; Wooster, G.A.; Britt, K.L.; Batts, W.N.; Winton, J.R.; Casey, R.N.; Casey, J.W.; Bowser, P.R.

    2007-01-01

    In May 2006 a large mortality of several thousand round gobies Neogobius melanostomus (Pallas, 1814) occurred in New York waters of the St. Lawrence River and Lake Ontario. Necropsies of sampled fish from these areas showed pallor of the liver and gills, and hemorrhagic areas in many organs. Histopathologic examination of affected tissues revealed areas of necrosis and hemorrhage. Inoculations of fathead minnow Pimephales promelas (Rafinesque, 1820) cell cultures with dilutions of tissue samples from the necropsied gobies produced a cytopathic effect within 5 d post-inoculation. Samples of cell culture supernatant were tested using RT-PCR and confirmed the presence of viral hemorrhagic septicemia virus (VHSV). Sequence analysis of the VHSV isolate resulted in its assignment to the type-IVb subgroup. The detection of VHSV in a relatively recent invasive fish species in the Great Lakes and the potential impact of VHSV on the ecology and economy of the area will require further investigation and careful management considerations. ?? Inter-Research 2007.

  15. Great Lakes Bathymetry

    Data.gov (United States)

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

  16. Diet of juvenile lake trout in southern Lake Ontario in relation to abundance and size of prey fishes, 1979-1987

    Science.gov (United States)

    Elrod, Joseph H.; O'Gorman, Robert

    1991-01-01

    We examined the diet of juvenile lake trout Salvelinus namaycush (zone where we caught the lake trout. Over all years combined, slimy sculpins Cottus cognatus contributed the most (39–52%) by wet weight to the diet, followed by alewives Alosa pseudoharengus(3–38%), rainbow smelt Osmerus mordax (17–43%), and johnny darters Etheostoma nigrum(2–10%). Over 90% of alewives eaten during April–May and June were age 1, and 98% of those eaten during October were age 0 (few alewives were eaten in July–August). Mean lengths of rainbow smelt and slimy sculpins in stomachs increased with size of lake trout. Juvenile lake trout generally fed opportunistically—seasonal and annual changes in diet usually reflected seasonal and annual changes in abundance of prey fishes near bottom where we captured the lake trout. Furthermore, diet within a given season varied with depth of capture of lake trout, and changes with depth in proportions of prey species in lake trout stomachs mirrored changes in proportions of the prey species in trawl catches at the same depth. Alewives (ages 0 and 1) were the only prey fish eaten in substantial quantities by both juvenile lake trout and other salmonines, and thus are a potential focus of competition between these predators.

  17. Water Resource Inventory and Assessment: Ruby Lake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Water Resource Inventory and Assessment report for Ruby Lake National Wildlife Refuge describes current hydrologic information, provides an assessment of water...

  18. Comparing health system performance assessment and management approaches in the Netherlands and Ontario, Canada

    NARCIS (Netherlands)

    A.R. Tawfik-Shukor (Ali); N.S. Klazinga (Niek); O.A. Arah (Onyebuchi)

    2007-01-01

    textabstractBackground. Given the proliferation and the growing complexity of performance measurement initiatives in many health systems, the Netherlands and Ontario, Canada expressed interests in cross-national comparisons in an effort to promote knowledge transfer and best practise. To support thi

  19. Wait Times for Sleep Apnea Care in Ontario: A Multidisciplinary Assessment

    Directory of Open Access Journals (Sweden)

    Brian W Rotenberg

    2010-01-01

    Full Text Available BACKGROUND: Obstructive sleep apnea (OSA is a highly prevalent disorder that is associated with significant patient morbidity and societal burden. In general, wait times for health care in Ontario are believed to be lengthy; however, many diseases lack specific corroborative wait time data.

  20. High-resolution lake sediment reconstruction of industrial impact in a world-class mining and smelting center, Sudbury, Ontario, Canada

    International Nuclear Information System (INIS)

    Highlights: • High-resolution sampling of a lake-sediment core. • Resolution of historical events in a smelter-impacted area. • Perturbation of Cu and Ni in a sediment core. • Fingerprinting sediments and pollutants using Pb isotopes and trace elements. - Abstract: A lake sediment core from Vermillion Lake, Sudbury, Ontario was tightly sampled and analyzed for a wide range of trace elements as well as for Pb isotopes. The data resolve multiple historical events in the 140-a history of logging and mining in the Sudbury area in unprecedented detail. Lead-210 data, 137Cs activity and historical information on the start of anthropogenic activities in the Sudbury area were combined to derive an age model for the sedimentary column. Using the age information, it is possible to identify sediment sections enriched and depleted in trace metal(loid)s, particularly Ni and Cu, the two most relevant metals in the Sudbury area. Maxima and minima in the chronology of Ni and Cu coincide well with local production values for both elements until environmental regulations in the 1990s resulted in a decrease in their emission and drainage into Vermillion Lake. Differences in the deposition rates of Ni and Cu, trace-metal distribution patterns throughout the sedimentary column, Pb-isotope data, and comparison with data for local rocks and ores in the Sudbury area were used to identify the sources of pollutants in the early and late periods of mining activities. In addition, the environmental impact on the sediment itself was also studied via the variation of water content and organic matter. Finally, a surficial Fe–Mn-enriched layer with elevated concentrations of the oxy-anions (PO4)3−, (AsO4)4−, and (MoO4)2− was identified. This can be distinguished from accumulation of Zn and an increase in the Y / Ho ratio in the upper core sections, which likely imply increasing drainage of fertilizers into the Vermillion River watershed. The chemistry, mineralogy, and isotope

  1. Fall diets of alewife, rainbow smelt, and slimy sculpin in the profundal zone of southern Lake Ontario during 1994-2005 with an emphasis on occurrence of Mysis relicta

    Science.gov (United States)

    Walsh, M.G.; O'Gorman, R.; Strang, T.; Edwards, W.H.; Rudstam, L. G.

    2008-01-01

    In Lake Ontario, factors including the collapse of the burrowing amphipod, Diporeia spp., changes in the distribution and composition of the prey fish community, and occurrence of exotic cladocerans Bythotrephes longimanus and Cercopagis pengoi have led to changes in predation pressure on the remaining native profundal macroinvertebrate, Mysis relicta. We conducted a diet study on three important prey fishes, alewife (Alosa pseudoharengus), rainbow smelt (Osmerus mordax), and slimy sculpin (Cottus cognatus) in 2002-2005 at depths 75-130 m along the south shore of Lake Ontario to evaluate the current role of Mysis in the diets of these species relative to earlier studies and previously unpublished data from 1994-1995. Mysis have remained an important prey item for alewife, rainbow smelt, and slimy sculpin in the profundal zone of southern Lake Ontario through 2005, indicating that the population has been able to sustain itself following the collapse of Diporeia. Although the occurrence of Diporeia in prey fish diets was minimal in 2003-2005, Bythotrephes longimanus and Cercopagis pengoi played an important role in the diet of alewife and a minor role in the diet of rainbow smelt, and may actually serve to mitigate predation pressure on Mysis, particularly in years when they are very abundant. Conversely, without Diporeia, the benthic slimy sculpin was primarily reliant on Mysis as a prey item and would be most vulnerable to a decline in the Mysis population. Copyright ?? 2008 AEHMS.

  2. Quantitative assessment of the hydraulic role of subglaciofluvial interbeds in promoting deposition of deformation till (Northern Till, Ontario)

    Science.gov (United States)

    Meriano, Mandana; Eyles, Nick

    2009-04-01

    The Northern Till is a thick (>65 m) deformation till underlying some 7500 km 2 of Southern Ontario, Canada including the Peterborough Drumlin Field. It was deposited below the Lake Ontario ice stream of the Laurentide Ice Sheet. The till rests on glaciotectonized aquifer sediments and consists of multiple beds of till up to 6 m thick. These are separated by boulder lags, sometimes in the form of striated pavements, with thin (punctuated aggradation' where the subglacial bed was built up incrementally by the repeated 'immobilization' of deforming overpressured till layers. Boulders and sands indicate pauses in subglacial aggradation marked by sluggish sheet flows of water that reworked the top of the underlying till. Interbeds are laterally extensive and correlated using downhole electrical conductivity, core recovery and natural gamma data. A 3-D finite element model (FEFLOW) using data from 200 cored and geophysically logged boreholes, and a large digital water well dataset of 3400 individual records shows that the till functions as a 'leaky aquitard' as a consequence of water flow through interbeds. It is proposed that interbeds played a similar role in the subglacial hydraulic system below the Laurentide Ice Sheet by allowing drainage of excess porewater pressures in deforming sediment and promoting deposition of till. This is in agreement with theoretical studies of deforming bed dynamics and observations at modern glaciers where porewater in the deforming layer is discharged into underlying aquifers. In this way, the presence of interbeds may be fundamental in retarding downglacier transport of deforming bed material thereby promoting the build-up of thick subglacial till successions.

  3. Assessing the effects of transboundary ozone pollution between Ontario, Canada and New York, USA

    International Nuclear Information System (INIS)

    Observations and modeling results were used to examine spatial scales and transport patterns of ozone pollution in the Ontario-New York region. - We investigated the effects of transboundary pollution between Ontario and New York using both observations and modeling results. Analysis of the spatial scales associated with ozone pollution revealed the regional and international character of this pollutant. A back-trajectory-clustering methodology was used to evaluate the potential for transboundary pollution trading and to identify potential pollution source regions for two sites: CN tower in Toronto and the World Trade Center in New York City. Transboundary pollution transport was evident at both locations. The major pollution source areas for the period examined were the Ohio River Valley and Midwest. Finally, we examined the transboundary impact of emission reductions through photochemical models. We found that emissions from both New York and Ontario were transported across the border and that reductions in predicted O3 levels can be substantial when emissions on both sides of the border are reduced

  4. Assessing the effects of transboundary ozone pollution between Ontario, Canada and New York, USA

    Energy Technology Data Exchange (ETDEWEB)

    Brankov, Elvira; Henry, Robert F.; Civerolo, Kevin L.; Hao, Winston; Rao, S.T.; Misra, P.K.; Bloxam, Robert; Reid, Neville

    2003-06-01

    Observations and modeling results were used to examine spatial scales and transport patterns of ozone pollution in the Ontario-New York region. - We investigated the effects of transboundary pollution between Ontario and New York using both observations and modeling results. Analysis of the spatial scales associated with ozone pollution revealed the regional and international character of this pollutant. A back-trajectory-clustering methodology was used to evaluate the potential for transboundary pollution trading and to identify potential pollution source regions for two sites: CN tower in Toronto and the World Trade Center in New York City. Transboundary pollution transport was evident at both locations. The major pollution source areas for the period examined were the Ohio River Valley and Midwest. Finally, we examined the transboundary impact of emission reductions through photochemical models. We found that emissions from both New York and Ontario were transported across the border and that reductions in predicted O{sub 3} levels can be substantial when emissions on both sides of the border are reduced.

  5. Biomass removal, retention, and costs associated with biomass harvesting in the partial harvest systems of Ontario's Great Lakes-Saint Lawrence forest region : preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, D. [Toronto Univ., ON (Canada). Faculty of Forestry

    2010-07-01

    Recent bioenergy policy developments in Ontario have increased interest in forest biomass supply research. Biomass harvested from clearcut and partial harvest system in the Great Lakes-Saint Lawrence (GLSL) region can be used to supply centralized pellet plants or directly to forest mill-based conversion facilities for electricity generation. Preliminary results from a biomass harvesting trial conducted in the GLSL have confirmed that whole-tree harvesting (WTH) and the removal of skid trail results in increased biomass removal and improved operational productivity relative to conventional cut-to-length methods. Biomass removals can be increased through the imposition of smaller minimum topping diameters and the harvesting of unmerchantable trees. The results of a study conducted to evaluate the difference between conventional and biomass harvesting in a shelterwood and selection system in the GLSL has indicated that increases in the amount of firewood and small, irregular blocks of wood recovered from biomass harvests are negligible compared with conventional harvesting practices. Biomass harvesting trials are currently being conducted to determine biomass removal and operational productivity calculations for determining the overall economic feasibility of biomass harvesting for energy in the region.

  6. Ontario's uranium mining industry

    International Nuclear Information System (INIS)

    This report traces the Ontario uranium mining industry from the first discovery of uranium north of Sault Ste. Marie through the uranium boom of the 1950's when Elliot Lake and Bancroft were developed, the cutbacks of the 1960s, the renewed enthusiasm in exploration and development of the 1970s to the current position when continued production for the domestic market is assured. Ontario, with developed mines and operational expertise, will be in a position to compete for export markets as they reopen. The low level of expenditures for uranium exploration and the lack of new discoveries are noted. The report also reviews and places in perspective the development of policies and regulations governing the industry and the jurisdictional relationships of the Federal and Provincial governments

  7. Retailers test Ontario market

    International Nuclear Information System (INIS)

    In anticipation of the full opening of the Ontario electricity market in November 2000, some of the newly-licensed electricity retailers are reported to be ready to begin testing the market early, hoping that all the uncertainties that still exist about pricing will be worked out in time. Among those jumping in now is Direct Energy Marketing, a retailer which claims 800,000 households in Ontario as electricity supply customers, as well as a wholesale gas marketing business. Direct Energy began retail electrical marketing on April 3, 2000, starting cautiously with small commercial operations as the initial target. Greengrid Electric, another of the new marketers, planned to begin marketing in mid-April, offering 100 per cent renewable-sourced electricity. Provident Energy Management, one of the new marketers whose licence is still pending, hopes to begin direct marketing as soon as its licence is confirmed. Another marketer ready to go as soon its license is issued is the former Sault Ste. Marie Hydro, now reorganized as PUC Energies Inc. PUC has the advantage of having a firm contract with a NUG (non-utility generator), Great Lakes Power, signed while PUC was still a municipal electric utility. As far as the other potential marketers are concerned, caution overrides opportunity for the present. Principal concerns are uncertainty over the retail settlement code, the electronic business data transfer system, transmission and distribution tariffs, whether existing non-utility generator contracts will allow for supply to another party, and over how quickly Ontario Power Generation Inc's (successor to Ontario Hydro) market power will be ratcheted down. Many of the potential marketers feel that despite the Ontario government's desire to see more competition, the power mitigation agreement, as it now reads, leaves little room for the small retailer to compete

  8. Environmental Assessment : Crescent Lake National Wildlife Refuge Hunting Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Environmental Assessment (EA) is for the implementation of the Crescent Lake National Wildlife Refuge Hunting Plan that serves as a step down management plan...

  9. Lake Mason : FWS rangeland inventory assessment

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In September 2013, The Lake Mason Unit owned by U.S. Fish and Wildlife Service was inventoried for rangeland health and production. The purpose of the inventory was...

  10. Occurrence and Habitat Use of Wintering Bald Eagles on Eastern Lake Ontario and the St. Lawrence River (1955-1993)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Occurrence and habitat use data for bald eagles (Haliaeetus leucocephalus), was compiled for use in planning a study to assess the potential effects of...

  11. Regional assessment of lake water clarity using satellite remote sensing

    Directory of Open Access Journals (Sweden)

    David L. SKOLE

    2003-09-01

    Full Text Available Lake water clarity as measured by Secchi disk transparency (SDT is a cost-effective measure of water quality. However, in regions where there are thousands of lakes, sampling even a small proportion of those lakes for SDT year after year is cost prohibitive. Remote sensing has the potential to be a powerful tool for assessing lake clarity over large spatial scales. The overall objective of our study was to examine whether Landsat-7 ETM+ could be used to measure water clarity across a large range of lakes. Our specific objectives were to: 1 develop a regression model to estimate SDT from Landsat data calibrated using 93 lakes in Michigan, U.S.A., and to 2 examine how the distribution of SDT across the 93 calibration lakes influenced the model. Our calibration dataset included a large number of lakes with a wide range of SDT values that captured the summer statewide distribution of SDT values in Michigan. Our regression model had a much lower r2 value than previously published studies conducted on smaller datasets. To examine the importance of the distribution of calibration data, we simulated a calibration dataset with a different SDT distribution by sub-sampling the original dataset to match the distribution of previous studies. The sub-sampled dataset had a much higher percentage of lakes with shallow water clarity, and the resulting regression model had a much higher r2 value than our original model. Our study shows that the use of Landsat to measure water clarity is sensitive to the distribution of water clarity used in the calibration set.

  12. Global assessment of nutrient loads to the world's largest lakes

    Science.gov (United States)

    Fink, Gabriel; Reder, Klara; Malsy, Marcus; Eisner, Stephanie; Flörke, Martina

    2015-04-01

    Lakes are essential resources of drinking water for a large part of mankind. Even so, most of the industrial and domestic waste water is discharged - often untreated - into rivers and streams that are finally the tributaries of these important freshwater bodies. Additionally, diffuse nutrient sources such as fertilizer and atmospheric deposition exacerbate existing algal blooms and low oxygen concentrations in rivers, lakes, and reservoirs. In this tense atmosphere of competing water uses, it is necessary to analyze all sources of pollution as well as their total contributions in order to protect these water bodies against deterioration. Finally, this is a general and urgently needed basis for developing recommendations for involved stakeholders and decision makers. Therefore, the project eartH2Observe, initiated and financed by the European Commission, creates the necessary and underlying quantitative and qualitative hydrological and water use data. In this context, information for global as well as for regional water resource assessments is being prepared based on new earth observations and an ensemble of global hydrological models. As a member of this ensemble, WaterGAP3 provides global estimates of lake water quality relevant parameters on a 5 arc minutes grid, namely total phosphorus and total nitrogen. These nutrient loads to lakes from different sources such as industrial fertilizer, organic fertilizer, domestic loads, atmospheric deposition, and urban surface runoff are estimated for the period 1990 to 2010 in a monthly time step. Whereas nutrient loads and their changes into numerous lakes worldwide are calculated, a special focus is set on nutrient loads into the large and shallow Lake Peipus, which is located between Estonia and Russia and subject to blooms of harmful cyanobacteria. We present estimates, trends, as well as sources of present nutrient loads (TN and TP) to the world's largest lakes with detailed insights to the Lake Peipus situation

  13. Community capacity to acquire, assess, adapt, and apply research evidence: a survey of Ontario's HIV/AIDS sector

    Directory of Open Access Journals (Sweden)

    Rourke Sean B

    2011-05-01

    Full Text Available Abstract Background Community-based organizations (CBOs are important stakeholders in health systems and are increasingly called upon to use research evidence to inform their advocacy, program planning, and service delivery. To better support CBOs to find and use research evidence, we sought to assess the capacity of CBOs in the HIV/AIDS sector to acquire, assess, adapt, and apply research evidence in their work. Methods We invited executive directors of HIV/AIDS CBOs in Ontario, Canada (n = 51 to complete the Canadian Health Services Research Foundation's "Is Research Working for You?" survey. Findings Based on responses from 25 organizations that collectively provide services to approximately 32,000 clients per year with 290 full-time equivalent staff, we found organizational capacity to acquire, assess, adapt, and apply research evidence to be low. CBO strengths include supporting a culture that rewards flexibility and quality improvement, exchanging information within their organization, and ensuring that their decision-making processes have a place for research. However, CBO Executive Directors indicated that they lacked the skills, time, resources, incentives, and links with experts to acquire research, assess its quality and reliability, and summarize it in a user-friendly way. Conclusion Given the limited capacity to find and use research evidence, we recommend a capacity-building strategy for HIV/AIDS CBOs that focuses on providing the tools, resources, and skills needed to more consistently acquire, assess, adapt, and apply research evidence. Such a strategy may be appropriate in other sectors and jurisdictions as well given that CBO Executive Directors in the HIV/AIDS sector in Ontario report low capacity despite being in the enviable position of having stable government infrastructure in place to support them, benefiting from long-standing investment in capacity building, and being part of an active provincial network. CBOs in other

  14. An exposure assessment for selected pharmaceuticals within a watershed in Southern Ontario.

    Science.gov (United States)

    Lissemore, Linda; Hao, Chunyan; Yang, Paul; Sibley, Paul K; Mabury, Scott; Solomon, Keith R

    2006-07-01

    Recent studies from a number of countries have shown that measurable concentrations of both human and veterinary pharmaceuticals can be found in a variety of environmental matrices such as surface and ground water, soils, and sediments. Few data are available that characterize the sources, exposure and effects of pharmaceuticals in the environment and there is clearly a need to define these parameters within a Canadian context. We present in this paper the first report in southern Ontario, Canada on the geographic and temporal distribution of pharmaceuticals detected within seven tributaries receiving primarily agricultural inputs in a typical watershed. Of the 28 pharmaceuticals surveyed, 14 were detected in the streams sampled (n=125). Temporal trends in concentration for five frequently detected pharmaceuticals show pulses occurring between May and November of 2003 at similar but varying times over the seasons, depending on the pharmaceuticals, flow rate, and precipitation. Fluctuations in concentration of ions indicative of agricultural run off, such as nitrate and phosphate, were not found to be useful predictors of changes in pharmaceutical concentration (P>0.4), however a significant correlation between dissolved organic carbon and monensin and carbamazepine concentrations were observed (PLemna gibba, and fish, the significance of non-target effects and impacts due to chronic low level exposures to chemical mixtures remains unclear. PMID:16403551

  15. Great Lakes Teacher's Guide.

    Science.gov (United States)

    Reid, Ron

    The Great Lakes are one of the world's greatest reservoirs of fresh water, the foundation of Ontario's economic development, a primary force in ecological systems, and a base for pleasure and recreation. They are also a magnificent resource for the teachers of Ontario. Study of the Great Lakes can bring to life the factors that shape the ecology…

  16. Geochemical and Rock Magnetic Properties of a Purple Sand Belt on Cedar Beach, Western Lake Erie, Ontario, Canada

    Science.gov (United States)

    Zhang, S.; Cioppa, M. T.; Zhang, S.

    2009-05-01

    Limited environmental magnetic studies have been carried out on beaches and shoreline processes. Therefore, we initiated a rock magnetic study at Cedar Beach on the north shore of western Lake Erie (42°N, 81°W) and noted the highest susceptibility values (9.6 x 10-2 SI) occurred in a purple sand belt that is 200m in length and 3.5m in width and located just outside the swash zone. To understand the rock magnetic properties of these purple sands, we systematically performed frequency-dependence of low-field susceptibility (Kfd%), partial anhysteretic remanent magnetization (pARM) spectra, saturation isothermal remanent magnetization (SIRM) acquisition, S-ratio, hysteresis measurements and Curie-point determinations for a set of representative purple sand samples. Most Kfd% values are lower than 1%, indicating that the dominant magnetic minerals fall in the large pseudo-single domain (PSD) to multidomain (MD) magnetic size, while single domain/super paramagnetic (SD/SP) grains are rare. pARM curves show only one group with a peak in the pARM spectra at 10 mT, indicating a low coercivity and a PSD to MD grain size (around 4 um). However, in a few samples, the pARM spectra at high coercivities (> 90mT) is not zero, suggesting the presence of either fine magnetic grains (SD magnetites) or high coercivity minerals (hematite or maghemite). Most IRM acquisition spectra show 95% of the magnetization gained below 200 mT, and S-300 ratios close to one, indicating the presence of fully saturated, coarse and fine magnetite. Some samples did not saturate until after 800 mT and showed two saturation levels, suggesting the presence of high coercivity minerals. High temperature susceptibility curves (K-T) and magnetization curves (Js-T) show Curie points (Tc) around 585°C, suggesting magnetite is the main magnetic mineral. The Js-T cycles are almost reversible, indicating that magnetic minerals have not been created or destroyed. Hysteresis curves are normally wasp- waisted

  17. Implications of sustainability assessment for electricity system design: The case of the Ontario Power Authority's integrated power system plan

    International Nuclear Information System (INIS)

    This paper explores the results and implications of an illustrative application of a sustainability assessment framework in the design and evaluation of a major integrated power system plan. The paper examines the integrated power system plan developed by the Ontario Power Authority in 2007. The basic framework rests on a generic set of evaluation criteria reflecting basic requirements for progress towards sustainability that was adopted, reinterpreted and applied by the Authority in support of its proposed plan. In response to evident deficiencies in the Authority's work, the authors and colleagues undertook a re-examination using a more fully elaborated sustainability assessment framework, specified for application to power system planning. The results point to a plan and plan components substantially different from those proposed by the Authority. More generally, the results highlight three advantages of applying such a sustainability assessment framework: comprehensive coverage of key requirements for progress towards sustainability while ensuring careful attention to the context and concerns of the sector; emphasis on identifying plan options that avoid major trade-offs among the sustainability criteria and recognition of interactions among the social, ecological, economic and technological realms favouring options that offer multiple, mutually reinforcing and lasting benefits.

  18. Development of indicators for assessment of Lake Malawi Basin in an Integrated Lake Basin Management (ILBM framework

    Directory of Open Access Journals (Sweden)

    Clara Limbitso Chidammodzi

    2015-03-01

    Full Text Available This paper sought to understand the current state of the management environment of Lake Malawi Basin, deduce a lake vision and develop indicators for assessing Integrated Lake Basin Management (ILBM in the lake basin. The premise of the study was that targeted indicators are necessary to effectively monitor the lake basin and manage it sustainably. The study focused on the Malawian side of the lake. Interviews, field observations and review of existing lake management and indicator development approaches around the world were the methods employed. It was found that Malawi lacks focus on lakes in its strategies and the existing management of the lake is on a sector-to-sector basis with little coordination. Furthermore, the capacity of lake-related sector institutions is hampered by inadequate resources and unstable flow of funds. It was concluded that the current management of the lake basin is unsustainable and there is need to comprehensively monitor the lake basin as well as formulate and implement management plans and strategies that are based on the knowledge obtained from targeted monitoring. A set of governance indicators was developed taking into account the characteristics of the lake, the values that it offers and the threats that it is facing.

  19. The application of resilience assessment - resilience of what, to what, with what? A case study based on Caledon, Ontario, Canada

    Directory of Open Access Journals (Sweden)

    Wai Ting Liu

    2014-12-01

    Full Text Available Resilience assessment can be used to determine major issues, stakeholders, vulnerabilities, and opportunities of a social-ecological system to enhance resilience. A resilience assessment was conducted on the Town of Caledon, Ontario between 2010 and 2011 using the Resilience Assessment Workbook for Practitioners (version 1. The assessment explores the following three questions: Resilience of what? Resilience to what? Resilience with what? The answer to the first question describes the history, main issues, and stakeholders of the focal system. The answers to the remaining two questions describe potential resilience threats and assets, respectively. The assessment results include (1 identified resilience threats and assets of Caledon as a social-ecological system in the context of urban growth; (2 a cross-scalar study of Caledon in its ecological, social, and economic domains; (3 interviews with 26 community members on the topics of urban growth and resilience; and (4 recommendations for Caledon to enhance its resilience in face of urban growth pressures. The results reveal the significance of continual learning, engaged citizenship, and cross-scalar collaboration between governmental bodies. The assessment results also highlight some particular features that would enhance the resilience of Caledon, such as nurturing the health of agroecosystems, developing trade-off rules for conflict resolution, and treating low-impact urban development as an opportunity. This research provides a case study of resilience assessment of a community that undergoes a rural-urban divide. Emerging themes of resilience are identified. Research limitations and suggestions are presented at the end of this paper.

  20. Analyzing Sustainable Energy Opportunities for a Small Scale Off-Grid Facility: A Case Study at Experimental Lakes Area (ELA), Ontario

    Science.gov (United States)

    Duggirala, Bhanu

    This thesis explored the opportunities to reduce energy demand and renewable energy feasibility at an off-grid science "community" called the Experimental Lakes Area (ELA) in Ontario. Being off-grid, ELA is completely dependent on diesel and propane fuel supply for all its electrical and heating needs, which makes ELA vulnerable to fluctuating fuel prices. As a result ELA emits a large amount of greenhouse gases (GHG) for its size. Energy efficiency and renewable energy technologies can reduce energy consumption and consequently energy cost, as well as GHG. Energy efficiency was very important to ELA due to the elevated fuel costs at this remote location. Minor upgrades to lighting, equipment and building envelope were able to reduce energy costs and reduce load. Efficient energy saving measures were recommended that save on operating and maintenance costs, namely, changing to LED lights, replacing old equipment like refrigerators and downsizing of ice makers. This resulted in a 4.8% load reduction and subsequently reduced the initial capital cost for biomass by 27,000, by 49,500 for wind power and by 136,500 for solar power. Many alternative energies show promise as potential energy sources to reduce the diesel and propane consumption at ELA including wind energy, solar heating and biomass. A biomass based CHP system using the existing diesel generators as back-up has the shortest pay back period of the technologies modeled. The biomass based CHP system has a pay back period of 4.1 years at 0.80 per liter of diesel, as diesel price approaches $2.00 per liter the pay back period reduces to 0.9 years, 50% the generation cost compared to present generation costs. Biomass has been successfully tried and tested in many off-grid communities particularly in a small-scale off-grid setting in North America and internationally. Also, the site specific solar and wind data show that ELA has potential to harvest renewable resources and produce heat and power at competitive

  1. Uranium and thorium deposits of Northern Ontario

    International Nuclear Information System (INIS)

    This, the second edition of the uranium-thorium deposit inventory, describes briefly the deposits of uranium and/or thorium in northern Ontario, which for the purposes of this circular is defined as that part of Ontario lying north and west of the Grenville Front. The most significant of the deposits described are fossil placers lying at or near the base of the Middle Precambrian Huronian Supergroup. These include the producing and past-producing mines of the Elliot Lake - Agnew Lake area. Also included are the pitchblende veins spatially associated with Late Precambrian (Keweenawan) diabase dikes of the Theano Point - Montreal River area. Miscellaneous Early Precambrian pegmatite, pitchblende-coffinite-sulphide occurrences near the Middle-Early Precambrian unconformity fringing the Lake Superior basin, and disseminations in diabase, granitic rocks, alkalic complexes and breccias scattered throughout northern Ontario make up the rest of the occurrences

  2. Assessment of water availability and demand in Lake Guiers , Senegal.

    Science.gov (United States)

    Sambou, D.; Weihrauch, D.; Hellwing, V.; Diekkrüger, B.; Höllermann, B.; Gaye, A. T.

    2015-12-01

    Assessment of water availability and demand in Lake Guiers, SenegalWater resources are critical to economic growth and social development. In most African countries, supply of drinking water to satisfy population needs is a key issue because of population growth and climate and land use change. During the last three decades, increasing population, changing patterns of water demand, and concentration of population and economic activities in urban areas has pressurize Senegal's freshwater resources. To overcome this deficit, Senegal turned, to the exploitation of the Lake Guiers. It is the sole water reservoir which can be used extensively as a stable freshwater. Its water is use for irrigating crops and sugar refinery and as a drinking water resource for urban centres, including Dakar, the capital city of Senegal, as well as for the local population and animal herds. To ensure sustainability, a greater understanding of Lake Guiers's water resources and effective management of its use will be required. In this study we developed and quantified future water situation (water availability and demand) in Lake Guiers under scenarios of climate change and population growth until 2050, using the water management model WEAP (Water Evaluation And Planning system). The results show that the pressure on Lake Guiers's water resources will increase, leading to greater competition between agriculture and municipal demand site. Decreasing inflows due to climate change will aggravate this situation. WEAP results offer basis to assister lake Guiers water resources manager for an efficient long-term planning and management. Keywords: climate change, population growth , IWRM, Lake Guiers, Senegal

  3. A methodology for risk assessment of municipal infrastructure due to climate change: a case study of London, Ontario

    Science.gov (United States)

    Bowering, E.; Peck, A.; Simonovic, S.

    2009-12-01

    Natural hazards are increasing in severity as a consequence of climate change. These hazards affect all aspects of municipal infrastructure. Thus a region must adapt its policies and procedures to mitigate the increasing risk to its infrastructure. The purpose of this study is to develop and test a methodology for engineering assessment of risk to municipal infrastructure due to climate change. Proposed methodology includes climate, hydrologic and hydraulic modeling as input for engineering risk assessment. Climate analysis uses Weather Generator as a tool to combine Global Circulation Models (GCMs) with regional historical data to output plausible climate scenarios. The present study focuses on flooding and temperature extremes which are relevant to the region under consideration. Hydrologic analysis uses the climate scenarios as input to the HEC-HMS model to determine streamflows. These streamflows are input to the HEC-RAS and GeoHEC-RAS as part of the hydraulic analysis to generate floodplain maps in a Geographic Information Systems (GIS) environment. The engineering risk assessment comprises of both quantitative and qualitative analyses. Water elevations and municipal infrastructure maps are combined using GIS to determine flood inundation levels. These loads are used in combination with infrastructure capacities to evaluate quantitative risk indices. Fuzzy set theory is used to address uncertainties associated with subjective criteria in qualitative analysis. This is accomplished by using membership functions to model ambiguity in various impact data interpretation. These membership functions are created through interviews held with experts in the fields of transportation, water supply and distribution, wastewater management and critical infrastructure management. Membership functions are used in qualitative fuzzy risk assessment. Quantitative and qualitative analysis are combined into risk indices which are spatially represented in GIS as risk maps for each

  4. Assessing the distribution of volatile organic compounds using land use regression in Sarnia, "Chemical Valley", Ontario, Canada

    Directory of Open Access Journals (Sweden)

    Luginaah Isaac N

    2009-04-01

    Full Text Available Abstract Background Land use regression (LUR modelling is proposed as a promising approach to meet some of the challenges of assessing the intra-urban spatial variability of ambient air pollutants in urban and industrial settings. However, most of the LUR models to date have focused on nitrogen oxides and particulate matter. This study aimed at developing LUR models to predict BTEX (benzene, toluene, ethylbenzene, m/p-xylene and o-xylene concentrations in Sarnia, 'Chemical Valley', Ontario, and model the intra-urban variability of BTEX compounds in the city for a community health study. Method Using Organic Vapour Monitors, pollutants were monitored at 39 locations across the city of Sarnia for 2 weeks in October 2005. LUR models were developed to generate predictor variables that best estimate BTEX concentrations. Results Industrial area, dwelling counts, and highways adequately explained most of the variability of BTEX concentrations (R2: 0.78 – 0.81. Correlations between measured BTEX compounds were high (> 0.75. Although most of the predictor variables (e.g. land use were similar in all the models, their individual contributions to the models were different. Conclusion Yielding potentially different health effects than nitrogen oxides and particulate matter, modelling other air pollutants is essential for a better understanding of the link between air pollution and health. The LUR models developed in these analyses will be used for estimating outdoor exposure to BTEX for a larger community health study aimed at examining the determinants of health in Sarnia.

  5. Forecasting Lake-Effect Snow in the Great Lakes Using NASA Satllite Data

    Science.gov (United States)

    Cipullo, Michelle; Molthan, Andrew; Shafer, Jackie; Case, Jonathan; Jedlovec, Gary

    2011-01-01

    This slide presentation reviews the forecast of the lake effect snow in the Great Lakes region using models and infrared estimates of Great Lake Surface Temperatures (GLSTs) from the MModerate Resolution Imaging Spectroradiometer (MODIS) instrument on Terra and Aqua satellites, and other satellite data. This study analyzes Lake Erie and Lake Ontario which produce storm total snowfall ranged from 8-18 inches off of Lake Ontario and 10-12 inches off of Lake Erie for the areas downwind.

  6. Data use investigations for applications Explorer Mission A (Heat Capacity Mapping Mission): HCMM's role in studies of the urban heat island, Great Lakes thermal phenomena and radiometric calibration of satellite data. [Buffalo, Syracuse, and Rochester New York and Lake Ontario

    Science.gov (United States)

    Schott, J. R. (Principal Investigator); Schimminger, E. W.

    1981-01-01

    The utility of data from NASA'a heat capacity mapping mission satellite for studies of the urban heat island, thermal phenomena in large lakes and radiometric calibration of satellite sensors was assessed. The data were found to be of significant value in all cases. Using HCMM data, the existence and microstructure of the heat island can be observed and associated with land cover within the urban complex. The formation and development of the thermal bar in the Great Lakes can be observed and quantitatively mapped using HCMM data. In addition, the thermal patterns observed can be associated with water quality variations observed both from other remote sensing platforms and in situ. The imaging radiometer on-board the HCMM satellite is shown to be calibratible to within about 1.1 C of actual surface temperatures. These findings, as well as the analytical procedures used in studying the HCMM data, are included.

  7. A Pan-Arctic Assessment of High-Latitude Lake Change ~25 Years Apart

    Science.gov (United States)

    Sheng, Y.; Smith, L. C.; Li, J.; Lyons, E. A.; Wang, J.

    2011-12-01

    The Arctic and Sub-Arctic regions are the home to the world's largest quantity of terrestrial lakes. These lakes play a preeminent role in the global water cycle and balance, are sensitive to global warming, and are vital for human and animal water supply. However, they are poorly observed, and a uniform lake inventory is unavailable at the pan-Arctic scale. Though there have been studies of Arctic lake dynamics at local scales, the general picture of Arctic lake change stays unclear. A systematic regional-scale assessment of Arctic lake change in the past ~30 years is crucial for us to address "How have Arctic lakes responded to global warming?" The presentation reports a systematic effort of high-latitude (45N and north) lake inventory using recently available high-resolution satellite imagery. Since Arctic lakes are abundant in small-size classes and their seasonality varies from region to region, pan-Arctic lake mapping requires the use of thousands of cloud-free Landsat images acquired in lake-stable seasons. Nearly eight million lakes have been mapped in various landscapes of the pan-Arctic using automated lake identification algorithms with high replicability. Lake-abundant regions are selected using a systematic sampling strategy to detect decadal lake change using the mid-1970s and circa-2000 Landsat imagery. Spatial patterns of the observed lake dynamics are analyzed at regional scales and the relationship between lake abundance and size distribution is investigated.

  8. Update to hazard assessment of selenium contamination at Benton Lake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes a study done to assess selenium levels on Benton Lake NWR. Water was sampled for dissolved selenium in Lake Creek at the point where it...

  9. A preliminary biological assessment of Long Lake National Wildlife Refuge Complex, North Dakota

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report represents an initial biological assessment of wetland conditions on Long Lake National Wildlife Refuge (NWR), Slade NWR, and Florence Lake NWR that was...

  10. The Potential for an Independent Source of Younger Dryas Tree-Ring Radiocarbon Data from the Lake Ontario Region, NE North America, and its Paleoenvironmental Context: a Preliminary Report

    Science.gov (United States)

    Griggs, C. B.; Southon, J. R.; Kromer, B.; Hogg, A.; Peteet, D. M.; Grote, T.; Cathles, L. M.; Lorentzen, B. E.; Kocik, C.; Kachuck, S.

    2015-12-01

    Tree rings are the gold standard for the calibration of radiocarbon dates into calendar years with limited error due to their annual record of radiocarbon content in the atmosphere. Currently, the tree-ring 14C data used in the International Radiocarbon Calibration curve (IntCal13) are from multiple sources back to ~ 10 ka cal BP for the northern hemisphere. However, the source for tree-ring calibration data prior to ~10 ka cal BP, including the Younger Dryas (YD) and most of the Early Holocene (EH) chronozones, is limited to central Europe. Substantial quantities of logs found in the lowlands of Lake Ontario in North America, dating from 12.1 to 11.2 ka cal BP, have great potential for providing unique YD-EH tree-ring 14C data from a new, previously unrepresented, geographic location and for adding a new perspective to ongoing debates such as the timing of the YD/EH transition in continental North America. Preliminary fieldwork yielded over 43 logs, predominantly spruce (Picea spp.), found buried in alluvial strata over 0.2 hectares of the floodplain at Bell Creek near Fulton, NY. Dendrochronological analysis of 32 spruce logs from this collection has produced several chronologies, one 183 years in length and a second of 147 years with a possible crossdate yielding a chronology of 260 years. Ongoing survey of the site suggests that there is high preservation potential in the same stratigraphic units in an additional ~2 hectares of floodplain, and sample collection with subsequent analysis will increase the chronology's sample depth, extend its length, and potentially provide a robust, independent Younger Dryas - Early Holocene 14C record. Initial assessments of climatic, hydrological, environmental, and isostatic variations and events over time from the tree rings and their stable isotopes, as well as pollen, macrofossil, and sediment analyses and isostatic modeling indicate substantial changes in the Bell Creek Valley and surrounding lowlands both during the YD

  11. Lake Mead Complex Final Gather Plan: Environmental Assessment

    OpenAIRE

    U.S. Department of the Interior, Bureau of Land Management, Grand Junction Field Office, Grand Junction, Colorado

    2007-01-01

    This Environmental Assessment (EA) has been prepared by the Bureau of Land Management (BLM) Las Vegas Field Office (LVFO) to analyze the environmental effects of a gather to remove approximately 195 resident wild burros from National Park Service-administered lands adjacent to the El Dorado Mountains, Gold Butte and Muddy Mountains Herd Management Areas (HMAs) within the Lake Mead Complex (LMC) in March 2007. The LMC is located in southern Nevada in Clark County. The BLM Las Vegas Field Offic...

  12. Monitoring and assessment of anthropogenic activities in mountain lakes: a case of the Fifth Triglav Lake in the Julian Alps.

    Science.gov (United States)

    Ravnikar, Tina; Bohanec, Marko; Muri, Gregor

    2016-04-01

    The Fifth Triglav Lake is a remote mountain lake in the Julian Alps. The area of the Julian Alps where the lake is situated is protected by law and lies within the Triglav National Park. Mountain lakes in Slovenia were considered for a long time as pristine, unpolluted lakes, but analyses in the last decade revealed considerable human impact even in such remote places. Eutrophication or excessive accumulation of nutrients is the main problem of most lakes in the temperate climatic zone, also in Slovenia. Since the introduction of fish in 1991, the lake is going through a series of changes for which we do not know exactly where they lead, so the monitoring and assessment of anthropogenic activities are of great importance. For this purpose, a qualitative multiattribute decision model was developed with DEX method to assess ecological effects on the lake. The extent of the ecological effects on the lake is assessed using four main parameters: the trophic state, lake characteristics, environmental parameters, and anthropogenic stressors. Dependence of environmental impact on various external factors beyond human control, such as temperature, precipitation, retention time, and factors on which we have influence, such as the amount of wastewater and the presence of fish in the lake, were also evaluated. The following data were measured: chlorophyll a, nutrients, TP, oxygen, C/N ratio, nutrients in sediment, temperature, precipitation, retention time, and volume. We made assumptions about fish and wastewater, which we could not measure. The main contributions of this work are the designed model and the obtained findings for the Fifth Triglav Lake that can help not only scientists in understanding the complexity of lake-watershed systems and interactions among system components but also local authorities to manage and monitor the lake aquatic environment in an effective and efficient way. The model is flexible and can be also used for other lakes, assuming that the used

  13. Environmental Assessment of a proposed reconstruction of the Lower Red Rock Lake dam : Red Rock Lakes National Wildlife Area

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Environmental Assessment (EA) for the renovation and attendant modifications to a water control dike on Red Rock Lakes National Wildlife Refuge, Montana. Completion...

  14. Value distribution assessment of geothermal development in Lake County, CA

    Energy Technology Data Exchange (ETDEWEB)

    Churchman, C.W.; Nelson, H.G.; Eacret, K.

    1977-10-01

    A value distribution assessment is defined as the determination of the distribution of benefits and costs of a proposed or actual development, with the intent of comparing such a development with alternative plans. Included are not only the social and economic effects, but also people's perceptions of their roles and how they are affected by the proposed or actual development. Discussion is presented under the following section headings: on morality and ethics; the vanishing community; case study of pre-development planning--Lake County; methodology for research; Lake County geothermal energy resource; decision making; Planning Commission hearing; communication examples; benefit tracing; response to issues raised by the report of the State Geothermal Task Force; and, conclusions and recommendations. (JGB)

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

    Science.gov (United States)

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

    1995-01-01

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

  16. Assessment of Lake Orta sediments phytotoxicity after the liming treatment

    Directory of Open Access Journals (Sweden)

    Daria ROSSI

    2001-08-01

    Full Text Available The paper presents results from seed germination and root elongation tests for the evaluation of Lake Orta sediment contamination. The protocol for this test was developed after a literature survey and careful investigation of the proper conditions for obtaining the germination of commercially available seeds of several plants. Cucumis sativus, Lactuca sativa, and Lepidium sativum were finally chosen and used to detect the phytotoxicity of both liquid and solid phases of Lake Orta sediments. To assess whether exchange at the water – sediment interface could represent a hazard for the environment and the actual bioavailability of the toxicants present into the sediments, the phytotoxicity of samples collected in 1992, 1994, 1996, 1997, and 1998 from selected stations was tested on seeds of three different plant species (Lactuca sativa, Lepidium sativum and Cucumis sativus. The obtained results allow drawing distribution maps of the germination index, which confirm the persistence of toxic effects. However, the lake seems to positively respond to the restoration treatment, since the more contaminated layers of sediments are presently buried under less toxic sediments.

  17. Macrophyte-Based Assessment of the Ecological Status of Lakes in Bulgaria

    OpenAIRE

    Gana M. Gecheva

    2011-01-01

    The aquatic macrophytes of lakes, situated in the whole territory of Bulgaria, were monitored during 2009. Six lake groups were established using differences in characteristics reflecting altitude, high calcium content and salinity, and altered hydromorphology and/or artificial origin. Abundance and species composition were assessed at each lake according to the requirements of the EU Water Framework Directive, using the assessment procedure of macrophyte-based assessment system, proposed by ...

  18. Climate Change Assessments for Lakes Region of Turkey

    Directory of Open Access Journals (Sweden)

    Ayten Erol

    2012-07-01

    Full Text Available Climate change is one of the most important challenges for forestry. Forests are known to be most efficient natural tools to ensure availability and quality of water in many regions. Besides, planning of forest resources towards water quality and quantity is essential in countries that are expected to face with more frequent drought periods in the next decades due to climate change. Watershed management concept has been supposed as the primary tool to plan natural resources in a more efficient and sustainable way by both academicians and practitioners to mitigate and adapt climate change. Forest cover among other land use types provides the best regulating mechanism to mitigate erosion, sedimentation, desertification, and pollution. In addition, climate change can potentially affect forest stand dynamics by influencing the availability of water resources. Therefore, the amount of forest cover in a watershed is an indicator of climate change mitigation and adaptation. Climate change is a concern and risk for the sustainability of water resources in Lakes Region of Turkey. The objective of this study is to make a comprehensive assessment in lake watersheds of the Lakes region considering the forest cover. For this purpose, the study gives a general view of trends in climatic parameters using Mann Kendall trend test. The results showed that Mann Kendall trend test for temperature and precipitation data is not enough to evaluate the magnitude of potential changes of climate in terms of forest cover. Understanding impacts of changes in temperature and precipitation on forest cover, runoff data should be evaluated with temperature and precipitation for watersheds of forest areas in Lakes Region.

  19. Ecosystem health assessment of urban rivers and lakes-Case study of "the six lakes" in Beijing,China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The assessment of the ecosystem health of urban rivers and lakes is the scientific basis for their management and ecological restoration.This study developed a three-level indicator system for its assessment.The results indicated that:Zhonghai and Nanhai are in the state of transition from unhealthy to critical state and all the other lakes are in unhealthy states.Water environmental quality,structure and function of the aquatic ecosystem,and the structure of waterfront areas were the constraints.Nanhai was ranked as poor and the others were all ranked as very poor.However,the ecological environment of Zhonghai and Nanhai were better than the others,the sums of the degree of membership to the healthy state and critical state were all close to 0.6.and the restorations of these lakes were moderate.The sums of the degree of membership to the healthy state and critical state of the other lakes were under 0.3,as it was difficult to restore these lakes.Some suggestions on scientific management and ecological restoration of the six lakes were improve the water quality of six lakes and the water ecosystem and waterfront areas.

  20. Development and application of the FAB model to calculate critical loads of S and N for lakes in the Killarney Provincial Park (Ontario, Canada)

    OpenAIRE

    Hindar, A.; Posch, M.; Gunn, John

    2000-01-01

    In Sudbury, Canada, large reductions in sulfur emissions have resulted in reduced critical load exceedances and partial recovery of many lakes in the Killarney Provincial Park. The First-order Acidity Balance (FAB) model to calculate critical loads (CLs) for surface water includes the potential acidifying part of nitrogen, and takes into account the retention of nitrogen in both the terrestrial and aquatic part of the catchment. We have applied the FAB model to Killarney-lakes, and critical l...

  1. Great Lakes Ice Charts

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Charts show ice extent and concentration three times weekly during the ice season, for all lakes except Ontario, from the 1973/74 ice season through the 2001/2002...

  2. Water quality assessment for Ulansuhai Lake using fuzzy clustering and pattern recognition

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Water quality assessment of lakes is important to determine functional zones of water use. Considering the fuzziness during the partitioning process for lake water quality in an arid area, a multiplex model of fuzzy clustering with pattern recognition was developed by integrating transitive closure method, ISODATA algorithm in fuzzy clustering and fuzzy pattern recognition. The model was applied to partition the Ulansuhai Lake, a typical shallow lake in arid climate zone in the west part of Inner Mongolia, China and grade the condition of water quality divisions. The results showed that the partition well matched the real conditions of the lake, and the method has been proved accurate in the application.

  3. Stock assessment of fishery target species in Lake Koka, Ethiopia.

    Science.gov (United States)

    Tesfaye, Gashaw; Wolff, Matthias

    2015-09-01

    Effective management is essential for small-scale fisheries to continue providing food and livelihoods for households, particularly in developing countries where other options are often limited. Studies on the population dynamics and stock assessment on fishery target species are thus imperative to sustain their fisheries and the benefits for the society. In Lake Koka (Ethiopia), very little is known about the vital population parameters and exploitation status of the fishery target species: tilapia Oreochromis niloticus, common carp Cyprinus carpio and catfish Clarias gariepinus. Our study, therefore, aimed at determining the vital population parameters and assessing the status of these target species in Lake Koka using length frequency data collected quarterly from commercial catches from 2007-2012. A total of 20,097 fish specimens (distributed as 7,933 tilapia, 6,025 catfish and 6,139 common carp) were measured for the analysis. Von Bertalarffy growth parameters and their confidence intervals were determined from modal progression analysis using ELEFAN I and applying the jackknife technique. Mortality parameters were determined from length-converted catch curves and empirical models. The exploitation status of these target species were then assessed by computing exploitation rates (E) from mortality parameters as well as from size indicators i.e., assessing the size distribution of fish catches relative to the size at maturity (Lm), the size that provides maximum cohort biomass (Lopt) and the abundance of mega-spawners. The mean value of growth parameters L∞, K and the growth performance index ø' were 44.5 cm, 0.41/year and 2.90 for O. niloticus, 74.1 cm, 0.28/year and 3.19 for C. carpio and 121.9 cm, 0.16/year and 3.36 for C. gariepinus, respectively. The 95 % confidence intervals of the estimates were also computed. Total mortality (Z) estimates were 1.47, 0.83 and 0.72/year for O. niloticus, C. carpio and C. gariepinus, respectively. Our study suggest that

  4. Hydrological budget of Lake Chad: assessment of lake-groundwater interaction by coupling Bayesian approach and chemical budget

    Science.gov (United States)

    Bouchez, Camille; Goncalves, Julio; Deschamps, Pierre; Seidel, Jean-Luc; Doumnang, Jean-Claude; Sylvestre, Florence

    2014-05-01

    Estimation of lake-groundwater interactions is a crucial step to constrain water balance of lacustrine and aquifer systems. Located in the Sahel, the Lake Chad is at the center of an endorheic basin of 2,5.106 km2. One of the most remarkable features of this terminal lake is that, despite the semi-arid context and high evaporation rates of the area, its waters are fresh. It is proposed in the literature that the solutes are evacuated in the underlying quaternary aquifer bearing witness to the importance of surface water and groundwater exchanges for the chemical regulation of the lake. The water balance of this system is still not fully understood. The respective roles of evaporation versus infiltration into the quaternary aquifer are particularly under constrained. To assess lake-groundwater flows, we used the previous conceptual hydrological model of the lake Chad proposed by Bader et al. (Hydrological Sciences Journal, 2011). This model involves six parameters including infiltration rate. A probabilistic inversion of parameters, based on an exploration of the parameters space through a Metropolis algorithm (a Monte Carlo Markov Chain method), allows the construction of an a posteriori Probability Density Function of each parameter yielding to the best fits between observed lake levels and simulated. Then, a chemical budget of a conservative element, such as chloride, is introduced in the water balance model using the optimal parameters resulting from the Bayesian inverse approach. The model simulates lake level and chloride concentration variations of lake Chad from 1956 up to 2008. Simulated lake levels are in overall agreement with the observations, with a Nash-Sutcliffe efficiency coefficient above 0.94 for all sets of parameters retained. The infiltration value, obtained by such probabilistic inversion approach, accounts for 120±20 mm/yr, representing 5% of the total outputs of the lake. However, simulated chloride concentrations are overestimated in

  5. Lake

    Science.gov (United States)

    Wien, Carol Anne

    2008-01-01

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

  6. An Assessment of the Expected Cost-Effectiveness of Quadrivalent Influenza Vaccines in Ontario, Canada Using a Static Model.

    Directory of Open Access Journals (Sweden)

    Ayman Chit

    Full Text Available Ontario, Canada, immunizes against influenza using a trivalent inactivated influenza vaccine (IIV3 under a Universal Influenza Immunization Program (UIIP. The UIIP offers IIV3 free-of-charge to all Ontarians over 6 months of age. A newly approved quadrivalent inactivated influenza vaccine (IIV4 offers wider protection against influenza B disease. We explored the expected cost-utility and budget impact of replacing IIV3 with IIV4, within the context of Ontario's UIIP, using a probabilistic and static cost-utility model. Wherever possible, epidemiological and cost data were obtained from Ontario sources. Canadian or U.S. sources were used when Ontario data were not available. Vaccine efficacy for IIV3 was obtained from the literature. IIV4 efficacy was derived from meta-analysis of strain-specific vaccine efficacy. Conservatively, herd protection was not considered. In the base case, we used IIV3 and IIV4 prices of $5.5/dose and $7/dose, respectively. We conducted a sensitivity analysis on the price of IIV4, as well as standard univariate and multivariate statistical uncertainty analyses. Over a typical influenza season, relative to IIV3, IIV4 is expected to avert an additional 2,516 influenza cases, 1,683 influenza-associated medical visits, 27 influenza-associated hospitalizations, and 5 influenza-associated deaths. From a societal perspective, IIV4 would generate 76 more Quality Adjusted Life Years (QALYs and a net societal budget impact of $4,784,112. The incremental cost effectiveness ratio for this comparison was $63,773/QALY. IIV4 remains cost-effective up to a 53% price premium over IIV3. A probabilistic sensitivity analysis showed that IIV4 was cost-effective with a probability of 65% for a threshold of $100,000/QALY gained. IIV4 is expected to achieve reductions in influenza-related morbidity and mortality compared to IIV3. Despite not accounting for herd protection, IIV4 is still expected to be a cost-effective alternative to IIV3 up to

  7. A new remote hazard and risk assessment framework for glacial lakes in the Nepal Himalaya

    Science.gov (United States)

    Rounce, David R.; McKinney, Daene C.; Lala, Jonathan M.; Byers, Alton C.; Watson, C. Scott

    2016-08-01

    Glacial lake outburst floods (GLOFs) pose a significant threat to downstream communities and infrastructure due to their potential to rapidly unleash stored lake water. The most common triggers of these GLOFs are mass movement entering the lake and/or the self-destruction of the terminal moraine due to hydrostatic pressures or a buried ice core. This study initially uses previous qualitative and quantitative assessments to understand the hazards associated with eight glacial lakes in the Nepal Himalaya that are widely considered to be highly dangerous. The previous assessments yield conflicting classifications with respect to each glacial lake, which spurred the development of a new holistic, reproducible, and objective approach based solely on remotely sensed data. This remote hazard assessment analyzes mass movement entering the lake, the stability of the moraine, and lake growth in conjunction with a geometric GLOF to determine the downstream impacts such that the present and future risk associated with each glacial lake may be quantified. The new approach is developed within a hazard, risk, and management action framework with the aim that this remote assessment may guide future field campaigns, modeling efforts, and ultimately risk-mitigation strategies. The remote assessment was found to provide valuable information regarding the hazards faced by each glacial lake and results were discussed within the context of the current state of knowledge to help guide future efforts.

  8. Gas restructuring in Ontario

    International Nuclear Information System (INIS)

    An overview of some of Ontario's policies which have led to natural gas restructuring in the province was presented. This presentation outlined the policy content of: (1) the White Paper - 'Directions for Change', (2) the Ontario Energy Board's advisory report on legislative change, and (3) the Energy Minister's consultation with gas stakeholders on the Ontario Energy Board recommendations. The major objectives of the policies (to allow markets to function more efficiently, to ensure fair access to monopoly services and to protect against unfair competition) are explained. Other objectives include modernizing regulatory processes and to strengthen consumer protection for small energy users. Major provisions of the Ontario's Energy Competition Act are also reviewed

  9. Environmental Status and geochemical assessment Sediments of Lake Skadar, Montenegro.

    Science.gov (United States)

    Kastratović, Vlatko; Jaćimović, Željko; Bigović, Miljan; Đurović, Dijana; Krivokapić, Slađana

    2016-08-01

    The environmental mobility and geochemical partitioning of ten metals were examined in sediments collected from the six locations around Lake Skadar in Montenegro. A three-step sequential extraction procedure was used to determine the distribution of the metals in various substrates of lacustrine sediments, and the concentrations were measured in the liquid extract by ICP-OES. The largest portion of the total amount of cadmium, strontium and manganese can be found in sediment bound to the hydrated iron and manganese oxides; cobalt, lead, copper and nickel in the oxidizable fraction and the highest portion of chromium, vanadium and zinc are in the residual fraction. The most mobilized and potentially mobile metals are strontium, cadmium and cobalt while the most immobilized metals are chromium, vanadium and zinc. Based on geochemical parameters, an assessment of sediment contamination by the investigated metals was performed and the results showed potential risks ranging from "no risk" to "low risk" to the environment. PMID:27384227

  10. Salt Lake City Area Integrated Projects: Rate adjustment: Environmental assessment

    International Nuclear Information System (INIS)

    The Department of Energy (DOE) has determined that the proposed firm power rate increase for the Salt Lake City Area Integrated Projects (Integrated Projects) power would not constitute a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 (NEPA, 42 USC 4321, et seq.) and, as such, does not require the preparation of an environmental impact statement (EIS). This determination is based on an environmental assessment (EA) prepared by the Western Area Power Administration (Western) dated August 1990 (DOE/EA-0457). The EA identifies and evaluates the potential environmental and socioeconomic effects of the proposed action, and based on the analysis contained therein, DOE concludes that the impacts to the human environment resulting from the implementation of the rate increase would be insignificant

  11. Macrophyte-Based Assessment of the Ecological Status of Lakes in Bulgaria

    Directory of Open Access Journals (Sweden)

    Gana M. Gecheva

    2011-12-01

    Full Text Available The aquatic macrophytes of lakes, situated in the whole territory of Bulgaria, were monitored during 2009. Six lake groups were established using differences in characteristics reflecting altitude, high calcium content and salinity, and altered hydromorphology and/or artificial origin. Abundance and species composition were assessed at each lake according to the requirements of the EU Water Framework Directive, using the assessment procedure of macrophyte-based assessment system, proposed by the Bavarian Environment Agency. The procedure included calculation of the ‘ecological quality ratio’ (EQR for each of 78 water bodies, based on transect monitoring data. For 31 of these lakes, a macrophyte assessment system was applied, for the remaining 47 lakes macrophyte quantity was insufficient or depopulation was assessed. Ecological status classification of lakes is based on the calculation of a Reference Index value. The Reference Index quantifies the deviation of species composition and abundance from reference conditions and classifies sites as one of the five possible ecological quality classes specified in the Directive. The EQR indicating Good and High (Maximum Ecological Status/Potential for macrophytes was achieved in 12 of the 31 lakes which fulfilled the criteria for assessment. The water quality parameters in lake types were discussed.

  12. Assessment on the Ecosystem Service Functions of Nansi Lake in China

    Directory of Open Access Journals (Sweden)

    Zhongyu Wang

    2016-03-01

    Full Text Available The assessment of ecosystem service functions is one of the focused area in modern ecological and environmental research. As a typical shallow macrophytic lake in China, Nansi Lake is selected as the study area. Based the indicator system and assessment models established in this research, the ecosystem service functions of Nansi Lake are assessed. The results show that the ecosystem service function of drinking water source area/aquatic product supply/ecological habitat/entertainment and landscape/ water purification function of the lakeside zone for Nansi Lake is assessed as medium (2.2/good (3.5/medium (3/medium (2.55/medium (3, and the overall ecosystem service function of Nansi Lake can be considered as ―Medium‖. The eutrophication control and ecological restoration of lakeside wetland need to be enhanced in the future.

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

    Directory of Open Access Journals (Sweden)

    G. Gunkel

    2009-05-01

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

  14. Mass balance assessment for mercury in Lake Champlain

    Science.gov (United States)

    Gao, N.; Armatas, N.G.; Shanley, J.B.; Kamman, N.C.; Miller, E.K.; Keeler, G.J.; Scherbatskoy, T.; Holsen, T.M.; Young, T.; McIlroy, L.; Drake, S.; Olsen, Bill; Cady, C.

    2006-01-01

    A mass balance model for mercury in Lake Champlain was developed in an effort to understand the sources, inventories, concentrations, and effects of mercury (Hg) contamination in the lake ecosystem. To construct the mass balance model, air, water, and sediment were sampled as a part of this project and other research/monitoring projects in the Lake Champlain Basin. This project produced a STELLA-based computer model and quantitative apportionments of the principal input and output pathways of Hg for each of 13 segments in the lake. The model Hg concentrations in the lake were consistent with measured concentrations. Specifically, the modeling identified surface water inflows as the largest direct contributor of Hg into the lake. Direct wet deposition to the lake was the second largest source of Hg followed by direct dry deposition. Volatilization and sedimentation losses were identified as the two major removal mechanisms. This study significantly improves previous estimates of the relative importance of Hg input pathways and of wet and dry deposition fluxes of Hg into Lake Champlain. It also provides new estimates of volatilization fluxes across different lake segments and sedimentation loss in the lake. ?? 2006 American Chemical Society.

  15. 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.

  16. Hydrogeological impacts of road salt from Canada's busiest highway on a Lake Ontario watershed (Frenchman's Bay) and lagoon, City of Pickering.

    Science.gov (United States)

    Meriano, Mandana; Eyles, Nick; Howard, Ken W F

    2009-06-26

    The quantity of deicing salt applied to paved surfaces in urban watersheds in cold regions has had a significant and cumulative effect on groundwater quality. Whereas road deicing salt is known in general to impact groundwater and surface water quality, quantitative information on the impact of large transport routes is lacking. In this study, we provide a chloride mass balance for an urban stream crossed by a large transport route in south-central Ontario, Canada and quantify likely long-term impacts of salt loading on surface and groundwater resources. The chloride mass balance, supported by hydrochemical analysis, reveals that approximately 50% of the total road salt applied to Pine Creek (1700 tonnes per winter) is removed annually via overland flow with the remainder accumulating in the shallow subsurface resulting in severe degradation of groundwater quality. Moreover, results show that road salt migration is the primary reason for enhanced mineral weathering in the shallow aquifer. During the 2004-05 salting season, runoff and baseflow transport of road salts were responsible for chloride concentrations in the stream of up to 2000 mg L(-1), and delivered approximately 850 tonnes of chloride (about 1400 tonnes of salt) to a shallow (watershed is estimated at 3700 tonnes each year with up to 48% of the total load delivered by baseflow, the remainder from surface water runoff. Present day groundwater chloride concentrations are estimated to be about 80% of long-term concentrations when the system reaches steady state. PMID:19464750

  17. Mysis diluviana population and cohort dynamics in Lake Ontario before and after the establishment of Dreissena spp., Cercopagis pengoi, and Bythotrephes longimanus

    Science.gov (United States)

    Johannsson, Ora E.; Bowen, Kelly L.; Holeck, Kristen T.; Walsh, Maureen G.

    2011-01-01

    We investigated population responses of Mysis to ecosystem changes induced by invasion of dreissenids and predatory cladocerans, Cercopagis and Bythotrephes. Lake productivity declined as dreissenids invaded the offshore region. Whole-lake mysid biomass was compared before (early 1990s) and after (2002–2007) the invasion period; it declined 40%–45%. Abundance of young mysids and presence of a summer cohort increased with summer, epilmnetic, nighttime zooplankton biomass (i.e., food biomass index). Cercopagis + Bythotrephes biomass was negatively correlated with this index, implicating them in the mysid decline. Eggs per gravid female increased with autumn, total-water-column zooplankton biomass, reflecting the greater use of hypolimnetic waters by adults. Reproductive success was below replacement during the period 2002–2005. First-year mysid growth rate was maintained while population abundance declined, suggesting selection for individuals that feed effectively at low food concentrations. Mortality rates in the first and second years were dependent on cohort density, indicating that competition for food limited abundance in the first 2 years. Fish predation indices (smelt and alewife combined) were correlated positively with mortality rates and negatively with abundance in the third year. Thus, mysids cannot support as many fish in invaded compared with non-invaded lakes. They may also not be a stable food resource; unusual cohort losses occurred in some years.

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

    Energy Technology Data Exchange (ETDEWEB)

    Harris, B. L. [Texas AgriLife Research, College Station, TX (United States); Roelke, Daniel [Texas AgriLife Research, College Station, TX (United States); Brooks, Bryan [Texas AgriLife Research, College Station, TX (United States); Grover, James [Texas AgriLife Research, College Station, TX (United States)

    2010-10-11

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

  19. Assessment of the fish tumor beneficial use impairment in brown bullhead (Ameiurus nebulosus) at selected Great Lakes Areas of Concern

    Science.gov (United States)

    Blazer, Vicki; Mazik, Patricia M.; Iwanowicz, Luke R.; Braham, Ryan P.; Hahn, Cassidy M.; Walsh, Heather L.; Sperry, Adam J.

    2014-01-01

    A total of 878 adult Brown Bullhead were collected at 11 sites within the Lake Erie and Lake Ontario drainages from 2011 to 2013. The sites included seven Areas of Concern (AOC; 670 individuals), one delisted AOC (50 individuals) and three non-AOC sites (158 individuals) used as reference sites. These fish were used to assess the “fish tumor or other deformities” beneficial use impairment. Fish were anesthetized, weighed, measured and any external abnormalities documented and removed. Abnormal orocutaneous and barbel tissue, as well as five to eight pieces of liver, were preserved for histopathological analyses. Otoliths were removed and used for age analyses. Visible external abnormalities included reddened (raised or eroded), melanistic areas and raised growths on lips, body surface, fins and barbels. Microscopically, these raised growths included papilloma, squamous cell carcinoma, osteoma and osteosarcoma. Proliferative lesions of the liver included bile duct hyperplasia, foci of cellular alteration, bile duct (cholangioma, cholangiocarcinoma) and hepatocellular (adenoma, hepatic cell carcinoma) neoplasia. The two reference sites (Long Point Inner Bay, Conneaut Creek), at which 30 or more bullhead were collected had a skin tumor prevalence of 10% or less and liver tumor prevalence of 4% or less. Presque Isle Bay, recently delisted, had a similar liver tumor prevalence (4%) and slightly higher prevalence (12%) of skin tumors. The prevalence of skin neoplasms was 15% or less at sites in the Black River, Cuyahoga River and Maumee AOCs, while more than 20% of the bullheads from the Rochester Embayment, Niagara River, Detroit River and Ashtabula River AOCs had skin tumors. The prevalence of liver tumors was greater than 4% at all AOC sites except the Old Channel site at the Cuyahoga River AOC, Wolf Creek within the Maumee AOC and the upper and lower sites within the Niagara River AOC.

  20. Selecting indicators to assess the fisheries of Lake Malawi and Lake Malombe: Knowledge base and evaluative capacity

    NARCIS (Netherlands)

    Zwieten, van P.A.M.; Banda, M.; Kolding, J.

    2011-01-01

    The provision of management information on the fisheries of Lakes Malawi and Malombe has been characterised by top–down controlled single species steady-state assessment techniques originating from single gear industrial fisheries but applied to an open access highly diverse and adaptive small-scale

  1. Assessment of mercury emissions inventories for the Great Lakes states

    International Nuclear Information System (INIS)

    Anthropogenic mercury (Hg) air emissions for the eight Great Lakes states in 1999-2000 were evaluated by analyzing three inventories. The US Environmental Protection Agency (EPA) National Emissions Inventory (NEI) had the most complete coverage for all states, and total Hg emissions ranged from 4226 lb in Minnesota to 15,828 lb in Pennsylvania. Coal-fired electric utilities accounted for 52.7% of the region's Hg emissions, varying from 20.2% of the total in New York to 67.5% in Ohio. Other important contributors to regional emissions included municipal waste combustion (5.6%), mercury-cell chlor-alkali plants and hazardous-waste incinerators (4% each), stationary internal combustion engines (ICEs) (3.5%), industrial, commercial, and institutional (ICI) boilers (3.3%), and lime manufacturing (3.0%). Although medical waste incineration accounted for just over 1% of regional emissions using the original classifications, the inclusion of health care facilities that may have been inappropriately identified with other sectors would increase the sector to 4.5% of regional emissions (and decrease the stationary ICE sector to 1.4% of the regional total). There were substantial differences for some sectors between the NEI and the Great Lakes Regional Air Toxics Emissions Inventory (GLEI), as well as unexplained differences within inventories between states (particularly for the cement, lime, and asphalt industries, and for lamp breakage). Toxics Release Inventory data for 2000 mainly covered electric utilities, and differences from the NEI were significant for several states. An independent assessment indicates the possibility of underestimated Hg emissions by about twofold for ICI boilers, although data for the sector (in particular concerning fuel oil emissions) are highly uncertain. Limited data indicate the likelihood of significant underestimates of electric arc furnace mercury emissions in the NEI and GLEI inventories. Several measures are here identified for improving

  2. Ontario electricity industry restructuring

    International Nuclear Information System (INIS)

    The objective of Ontario's electricity industry restructuring was described as an effort to enhance Ontario's competitiveness. It is believed that restructuring can be accomplished without an increase in electricity rates. In a series of charts, the report provides the timeline of restructuring from the time of the Macdonald report in 1995 to the beginning of open competition in Ontario electricity markets. It oulines the principles underlying the financial restructuring and the financial results of restructuring, including the size of the stranded debt ($ 7.8 billion). It lists the changes that have occurred since October 1998, explains some key factors in valuing the successor companies and profiles the Ontario Electricity Financial Corporation. Restructuring of the industry is expected to have a neutral to positive impact on Ontario's fiscal position. The residual stranded debt of $7.8 billion will be retired through revenues generated by the electricity sector, without recourse to the Provincial Treasury. 9 figs

  3. Restructuring the Ontario market

    International Nuclear Information System (INIS)

    The progress that Ontario has made toward refining the electric power market in that province was reviewed. Ontario's Energy Competition Act which was passed in 1998 breaks up Ontario Hydro and Municipal Electric Utilities. This opens the electricity market to competition for year 2000. The opportunities and challenges that this presents to Union Gas were discussed. The lessons learned from the natural gas industry with respect to retail access were described. The impact that the changes in Ontario Hydro and natural gas industry restructuring will have on energy suppliers were also discussed. It was shown that about half of Ontario residential customers purchase natural gas from energy marketers. The challenge facing regulators is to provide a level playing field for all energy suppliers. 1 fig

  4. Ontario energy review

    International Nuclear Information System (INIS)

    This publication provides a review of the developments in Ontario in relation to the national and international energy scene. Ontario is the largest energy consumer in Canada and is highly dependent on external energy sources. Several developments have significantly altered the Ontario energy scene. Oil and gas markets have become deregulated and market forces increasingly determine prices. A free trade agreement with the United States makes Ontario even more affected by international markets. Oil and gas prices have fallen from the high levels of the 1980s, but energy efficiency and conservation continue to be extremely important because they affect economic performance and the environment. In the next few years the greatest challenges will be to continue improving energy efficiency, to reduce the impact of energy on the environment, and to ensure the availability of sufficient energy supplies for future needs. This review contains statistics on energy in Ontario and explains them for the non-specialist. (7 tabs., figs.)

  5. Sediment quality assessment of Beasley Lake: Bioaccumulation and effects of pesticides in Hyalella azteca

    Science.gov (United States)

    Beasley Lake is a Conservation Evaluation Assessment Program (CEAP) watershed in the intensively cultivated Mississippi Delta, USA. Lake sediment quality at three sites was evaluated in 2004 and 2008 for biological impairment and uptake (viz. body residues) from 14 pesticides and three metabolites ...

  6. Lake Whitney Comprehensive Water Quality Assessment, Phase 1B- Physical and Biological Assessment (USDOE)

    Energy Technology Data Exchange (ETDEWEB)

    Doyle, Robert D; Byars, Bruce W

    2009-11-24

    assessment of knowledge of watershed and water quality related issues by local residents and stakeholders of Lake Whitney and design an intervention educational program to address any deficiencies discovered. Phase IA was funded primarily from EPA Cooperative Agreement X7-9769 8901-0. Phase IC (USEPA, QAPP Study Element 5) of this research focused on the ambient toxicity of the reservoir with respect to periodic blooms of golden algae. Phase IC was funded primarily from Cooperative Agreement EM-96638001. Phase 1B (USDOE, Study Elements 6-11) complemented work being done via EPA funding on study elements 1-5 and added five new study elements: 6) Salinity Transport in the Brazos Watershed to Lake Whitney; 7) Bacterial Assessment; 8) Organic Contaminant Analysis on Lake Whitney; 9) Plankton Photosynthesis; 10) Lake Whitney Resident Knowledge Assessment; and 11) Engineering Scoping Perspective: Recommendations for Use.

  7. Moraine-dammed lake failures in Patagonia and assessment of outburst susceptibility in the Baker Basin

    Directory of Open Access Journals (Sweden)

    P. Iribarren Anacona

    2014-07-01

    Full Text Available Glacier retreat since the Little Ice Age has resulted in the development or expansion of hundreds of glacial lakes in Patagonia. Some of these lakes have produced large (≥106 m3 Glacial Lake Outburst Floods (GLOFs damaging inhabited areas. GLOF hazard studies in Patagonia have been mainly based on the analysis of short-term series (≤50 years of flood data and until now no attempt has been made to identify the relative susceptibility of lakes to failure. Power schemes and associated infrastructure are planned for Patagonian basins that have historically been affected by GLOFs, and we now require a thorough understanding of the characteristics of dangerous lakes in order to assist with hazard assessment and planning. In this paper, the conditioning factors of 16 outbursts from moraine dammed lakes in Patagonia were analysed. These data were used to develop a classification scheme designed to assess outburst susceptibility, based on image classification techniques, flow routine algorithms and the Analytical Hierarchy Process. This scheme was applied to the Baker Basin, Chile, where at least 7 moraine-dammed lakes have failed in historic time. We identified 386 moraine-dammed lakes in the Baker Basin of which 28 were classified with high or very high outburst susceptibility. Commonly, lakes with high outburst susceptibility are in contact with glaciers and have moderate (>8° to steep (>15° dam outlet slopes, akin to failed lakes in Patagonia. The proposed classification scheme is suitable for first-order GLOF hazard assessments in this region. However, rapidly changing glaciers in Patagonia make detailed analysis and monitoring of hazardous lakes and glaciated areas upstream from inhabited areas or critical infrastructure necessary, in order to better prepare for hazards emerging from an evolving cryosphere.

  8. Lake Assessment Project Report, Lake Andes: Charles Mix County, South Dakota

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Lake Andes was included in the 1998 South Dakota 303(d) list as an impairment-related Total Maximum Daily Load waterbody. In 1922 Congress passed a bill that...

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

    Data.gov (United States)

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

  10. Rabbit Lake uranium mining a-zone, d-zone, eagle point: report of the environmental assessment panel

    International Nuclear Information System (INIS)

    A report of the environmental assessment panel on Rabbit Lake, Saskatchewan. A review of the proposed development of the uranium mining facility at Rabbit Lake with respect to the environmental, health, safety, and socioeconomic impacts

  11. Hazard assessment of selenium contamination at Benton Lake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes a study done to assess selenium levels on Benton Lake NWR. Because selenium is not evenly distributed across wetland units, sampling in 2006...

  12. Environmental Assessment: Sport Hunting Plan for Crescent Lake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Environmental Assessment (EA) considers four alternatives for expanding hunting on Crescent Lake NWR. The preferred alternative is to expand hunting...

  13. Ecobiological assessment of a freshwater lake at Schirmacher Oasis, East Antarctica, with reference to human activities

    Digital Repository Service at National Institute of Oceanography (India)

    Ingole, B.S.; Dhargalkar, V.K.

    The scale and magnitude of probable impact of human activities over a decade (1983-1994) on the freshwater lake Priyadarshini, at Schirmacher Oasis, East Antarctica, was assessed through an ecological study conducted over an annual cycle during...

  14. Application of Landsat 8 imagery to regional-scale assessment of lake water quality

    Science.gov (United States)

    Andrzej Urbanski, Jacek; Wochna, Agnieszka; Bubak, Iwona; Grzybowski, Waldemar; Lukawska-Matuszewska, Katarzyna; Łącka, Magda; Śliwińska, Sylwia; Wojtasiewicz, Bożena; Zajączkowski, Marek

    2016-09-01

    The aim of the project was to create a tool with which to support regional lake quality assessment using Landsat 8 imagery data. The model of assigning the ecological status was implemented in GIS for the northern part of Poland and classifies lake quality for several classes according to classification of WFD using two basic assumptions. The first is that there exists a combination of OLI bands (OLI2/OLI4 was used) which correlates well with the trophic state of the lakes; the second assumption is that the reference trophic state depends on the mean depth of the lake. The model uses a lake geodatabase which contains lakes outlines, raster masks of lakes and attribute information about their mean depth. There is no need to provide any field data when using this tool, as calibration of the model is done using subsets of lakes which were classified using legally defined methods. The tool allows fast classification of 2800 lakes from the area of interest. The results show good agreement between satellite and expert based methods.

  15. Water Quality Index for Assessment of Rudrasagar Lake Ecosystem, India

    Directory of Open Access Journals (Sweden)

    Joyanta pal

    2016-01-01

    Full Text Available Water quality of lakes, rivers and reservoirs in developing countries like India is being degraded because of the contaminated inflows and surrounding influence. There is a serious need for appropriate water quality monitoring for future planning and management of Lake and other type of water resources. Quality of water in Rudrasagar Lake, Tripura, India has been investigated in this paper. Water Quality Index (WQI was applied in Rudrasagar Lake India using water quality parameters like pH, Turbidity, Conductivity, Hardness, Alkalinity, Dissolved Oxygen, Biochemical Oxygen Demand and Nitrate. Based on the importance of the parameter for aquatic life the relative weight is assigned to each water quality parameter ranged from 1 to 4. Tests were performed on site using electronic measuring device as well as on Laboratory with samples of water collected from different locations of Rudrasagar Lake. It shows that water quality of Rudrasagar Lake falls within the ‗good water‘ category but marginally. Continuous monitoring of Rudrasagar lake is suggested for proper management.

  16. The interaction of large amplitude internal seiches with a shallow sloping lakebed: observations of benthic turbulence in Lake Simcoe, Ontario, Canada.

    Science.gov (United States)

    Cossu, Remo; Wells, Mathew G

    2013-01-01

    Observations of the interactions of large amplitude internal seiches with the sloping boundary of Lake Simcoe, Canada show a pronounced asymmetry between up- and downwelling. Data were obtained during a 42-day period in late summer with an ADCP and an array of four thermistor chains located in a 5 km line at the depths where the thermocline intersects the shallow slope of the lakebed. The thermocline is located at depths of 12-14 m during the strongly stratified period of late summer. During periods of strong westerly winds the thermocline is deflected as much as 8 m vertically and interacts directly with the lakebed at depth between 14-18 m. When the thermocline was rising at the boundary, the stratification resembles a turbulent bore that propagates up the sloping lakebed with a speed of 0.05-0.15 m s(-1) and a Froude number close to unity. There were strong temperature overturns associated with the abrupt changes in temperature across the bore. Based on the size of overturns in the near bed stratification, we show that the inferred turbulent diffusivity varies by up to two orders of magnitude between up- and downwellings. When the thermocline was rising, estimates of turbulent diffusivity were high with KZ ∼10(-4) m(2)s(-1), whereas during downwelling events the near-bed stratification was greatly increased and the turbulence was reduced. This asymmetry is consistent with previous field observations and underlines the importance of shear-induced convection in benthic bottom boundary layers of stratified lakes.

  17. The interaction of large amplitude internal seiches with a shallow sloping lakebed: observations of benthic turbulence in Lake Simcoe, Ontario, Canada.

    Directory of Open Access Journals (Sweden)

    Remo Cossu

    Full Text Available Observations of the interactions of large amplitude internal seiches with the sloping boundary of Lake Simcoe, Canada show a pronounced asymmetry between up- and downwelling. Data were obtained during a 42-day period in late summer with an ADCP and an array of four thermistor chains located in a 5 km line at the depths where the thermocline intersects the shallow slope of the lakebed. The thermocline is located at depths of 12-14 m during the strongly stratified period of late summer. During periods of strong westerly winds the thermocline is deflected as much as 8 m vertically and interacts directly with the lakebed at depth between 14-18 m. When the thermocline was rising at the boundary, the stratification resembles a turbulent bore that propagates up the sloping lakebed with a speed of 0.05-0.15 m s(-1 and a Froude number close to unity. There were strong temperature overturns associated with the abrupt changes in temperature across the bore. Based on the size of overturns in the near bed stratification, we show that the inferred turbulent diffusivity varies by up to two orders of magnitude between up- and downwellings. When the thermocline was rising, estimates of turbulent diffusivity were high with KZ ∼10(-4 m(2s(-1, whereas during downwelling events the near-bed stratification was greatly increased and the turbulence was reduced. This asymmetry is consistent with previous field observations and underlines the importance of shear-induced convection in benthic bottom boundary layers of stratified lakes.

  18. Content and Ecological Risk Assessment of Heavy Metals in Surface Sediment in Weishan Lake

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The aim was to analyze the content of heavy metals in surface sediment in Weishan Lake and further assess its ecological risk.[Method] Heavy metal pollution in surface sediment in Weishan Lake was studied,and the pollution indices and potential ecological risk indices of Cu,Zn,Pb,Cd and Cr were calculated to assess the potential ecological risk of heavy metal pollution.[Result] In surface sediment in Weishan Lake,the average contents of Cu,Zn,Pb,Cd,Cr and Ni were 64.78,185.05,78.76,0.17,37.76 an...

  19. Draft Mercury Aquatic Wildlife Benchmarks for Great Salt Lake Assessment

    Science.gov (United States)

    This document describes the EPA Region 8's rationale for selecting aquatic wildlife dietary and tissue mercury benchmarks for use in interpreting available data collected from the Great Salt Lake and surrounding wetlands.

  20. NV - Assessment of wildlife hazards associated with mine pit lakes

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Several open pit mines in Nevada lower groundwater to mine ore below the water table. After mining, the pits partially fill with groundwater to form pit lakes....

  1. Temporal Variation of Eutrophication Assessment of Lake Bosomtwe, Ghana

    Directory of Open Access Journals (Sweden)

    Adams Sadick

    2016-06-01

    Full Text Available Bosomtwe Lake is a freshwater lake in the Ashanti Region of Ghana, and is the habitat for many native plant and animal species. It is also a place for tourism and, therefore, the water quality and health status of the lake are vital for conservation of species and tourism. The main objective of this study was to examine the water quality of the lake in relation to nutrient load and possible eutrophication of the lake. It also explored the correlation between some physico-chemical parameters of the lake to inform policy direction on a watershed management strategy of the lake. A total of 40 samples were taken from different parts on the lake for analysis. This was done during the wet and dry seasons in 2012 and 2013. The results showed a general lower concentration of these parameters in the wet season and a higher concentration in the dry season.  The statistical results also indicated a negative correlation between Total Nitrogen and Total Phosphorus (r = -0.839, p = 0.075, Total Nitrogen and Total Dissolved Solid  (r = -0.771, p = 0.125, Total Nitrogen and Dissolved Oxygen (r = -0.749, p = 0.145 and Total Nitrogen and pH (r = -0.754, p = 0.141. However, Total Phosphorus showed a positive correlation with Total Dissolved Solid (r = 0.670, p = 0.216, Dissolved Oxygen  (r = 0.830, p = 0.085, pH (r = 0.546, p = 0.314 and Temperature (r = 0.427, p = 474. The nutrient load on the lake water though low, it has the potential to increase the eutrophication of the lake if not controlled and this will be dangerous for ecological entities within the catchment. The association between TP and TDS should be closely monitored since there was a strong positive correlation between them.  The major setback of this study was unavailability of the facilities to analyse colour, turbidity, faecal coliform, Escherichia coli count, chlorophyll-a, and algal growth in the lake.

  2. Inquiries and technological assessment

    International Nuclear Information System (INIS)

    The authors examine six Canadian inquiries to determine their values as scientific assessments, their ability to combine scientific data with policy considerations, and their effectiveness in extending public debate on scientific issues. Among the inquiries examined are the environmental assessment hearings into the Point Lepreau nuclear generating station, the Bayda inquiry into the Cluff Lake uranium mine, and the Porter commission on electric power planning in Ontario

  3. Expansion of the uranium mines in the Elliot Lake area

    International Nuclear Information System (INIS)

    This report forms the response of the government of Ontario to an earlier report issued by an Envrionmental Assessment Board. Specifically, the report deals with the rapid growth of the town of Elliot Lake due to expansion of several uranium mine-mill operations. Rapid growth of small communities presents considerable problems in providing housing, essential services, and educational facilities. Several specific actions taken by the government to help the town cope with rapid growth are presented. (O.T.)

  4. 3-D Eutrophication Modeling for Lake Simcoe, Canada

    Science.gov (United States)

    Lu, Q.; Duckett, F.; Nairn, R.; Brunton, A.

    2006-12-01

    The Lake Simcoe Region Conservation Authority (LSRCA) and the Province of Ontario are undertaking a series of studies to facilitate management of the pressures of population growth in the Lake Simcoe watershed. With rapid population growth and urban development comes additional land clearing, storm water runoff and the discharge of treated sewage, all of which are sources of increased phosphorus loading to Lake Simcoe. Depressed oxygen levels were linked to phosphorous enrichment of the lake, with the resultant stimulation of algal growth in the sunlit upper waters of the lake, and its subsequent senescence and settling into the hypolimnion where bacterial decomposition consumes oxygen from the stratified waters. This poster describes a 3-D hydrodynamic, thermal and water quality model of Lake Simcoe developed using the Danish Hydraulics Institute (DHI) MIKE3 model. The hydrodynamic module includes wind-driven circulation, temperature variation, development of the thermocline and thermal stratification, and hydraulic forcing from inflowing tributaries. This is linked to the water quality module which simulates the eutrophication processes in the response of the lake to loadings of phosphorus, such as algal growth, the growth of aquatic plants and subsequent oxygen consumption. The model has been calibrated against Acoustic Doppler Current Profiler velocity data, plus measured temperature and water quality data at MOE stations in the lake and water intakes. The model is an important assessment tool for the management of the lake and its watersheds, allowing assessment of the impacts of the urban growth and land use change on the water quality in Lake Simcoe.

  5. 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

    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...... end of the nutrient gradient, using contemporary chironomid assemblages and environmental parameters from 12 British lakes, although this had little improvement on the model performances. 2. Dissimilarity analyses showed that the historic chironomid assemblages did not have good analogues in the...

  6. Assessment of pesticide contamination in three Mississippi Delta oxbow lakes using Hyalella azteca.

    Science.gov (United States)

    Moore, M T; Lizotte, R E; Knight, S S; Smith, S; Cooper, C M

    2007-05-01

    Three oxbow lakes in northwestern Mississippi, USA, an area of intensive agriculture, were assessed for biological impairment from historic and current-use pesticide contamination using the amphipod, Hyalella azteca. Surface water and sediment samples from three sites in each lake were collected from Deep Hollow, Beasley, and Thighman Lakes from September 2000 to February 2001. Samples were analyzed for 17 historic and current-use pesticides and selected metabolites. Ten-day H. azteca survival and growth (as length and dry weight) were measured to determine the degree of biological impairment. Maximum number of detectable pesticides in surface water from Deep Hollow, Beasley and Thighman Lakes was 10, 11, and 17, respectively. Maximum number of detectable pesticides in lake sediments was 17, 17, and 15, respectively. Bioassay results indicated no observable survival effects on H. azteca exposed to surface water or sediment from any lake examined and no growth impairment in animals exposed to lake sediments. However, growth was significantly impaired in surface water exposures from Deep Hollow Lake (2 sites) and Beasley Lake (1 site). Statistically significant relationships between growth impairment (length) and cyanazine, methyl parathion, lambda-cyhalothrin, chlorfenapyr, and pp'DDE surface water concentrations in Deep Hollow Lake as well as trifluralin, atrazine, and methyl parathion in Beasley Lake were observed. Although pesticide frequency and concentrations were typically greater in sediment than surface water, bioassay results indicated decreased availability of these pesticides in sediment due to the presence of clay and organic carbon. Growth impairment observed in surface water exposures was likely due to complex interaction of pesticide mixtures that were present. PMID:17258272

  7. 78 FR 11670 - Eastern Great Lakes Area Maritime Security Committee; Vacancies

    Science.gov (United States)

    2013-02-19

    ... SECURITY Coast Guard Eastern Great Lakes Area Maritime Security Committee; Vacancies AGENCY: Coast Guard... the Area Maritime Security Committee, Eastern Great Lakes, and its five regional subcommittees: Northeast Ohio Region, Northwestern Pennsylvania Region, Western New York Region, Lake Ontario Region,...

  8. Ontario interim market

    International Nuclear Information System (INIS)

    Ontario's White Paper outlined the government's plan to restructure the electric power industry to an open market by the year 2000. Bill 35, when passed, will be the legislation required to start the process of electricity restructuring laid out in the White Paper. In the section dealing with the Independent Market Operator, the White Paper states that the Ontario government, as a transitional step to an open market, will introduce an element of competition into the industry by establishing an interim market for replacement power and impose a discipline on Ontario Hydro. Unfortunately, this transitional step did not live up to its billing and has had a minimal impact on both Ontario Hydro and the marketplace. Nevertheless, the experiment has provided a peek into the future of electricity and power pricing in Ontario, by making price information available and posted on the Internet. This paper examines how informative this experience has been and looks at the year just past in perspective. One of the notable developments was that the threat of a power shortage as a result of shutting down seven of Ontario Hydro's nuclear reactors, did not materialize. Ontario Hydro's fossil fuel generation plants were able to step into the breach and generate enough energy to make up for the reduction in nuclear production, and did so within the allowable limit for acid gas emissions. Some interesting developments in pricing electric power exported to the US in the summer of of 1998 are also reviewed for what they can teach us about the value of transparency and full price disclosure. 2 figs

  9. Planktic Tychonema (Cyanobacteria) in the large lakes south of the Alps: phylogenetic assessment and toxigenic potential.

    Science.gov (United States)

    Salmaso, Nico; Cerasino, Leonardo; Boscaini, Adriano; Capelli, Camilla

    2016-10-01

    This work allowed assessing a widespread occurrence of Tychonema bourrellyi in the largest lakes south of the Alps (Garda, Iseo, Como and Maggiore). The taxonomy of the species was confirmed adopting a polyphasic approach, which included microscopic examinations, molecular (16S rRNA and rbcLX sequences) and (Lake Garda) ecological characterisations. Over 70% of the 36 isolates of Tychonema sampled from the four lakes tested positive for the presence of genes implicated in the biosynthesis of anatoxins (anaF and/or anaC) and for the production of anatoxin-a (ATX) and homoanatoxin-a (HTX). A detailed analysis carried out in Lake Garda showed strong ongoing changes in the cyanobacterial community, with populations of Tychonema developing with higher biovolumes compared to the microcystins (MCs) producer Planktothrix rubescens Moreover, the time × depth distribution of Tychonema was paralleled by a comparable distribution of ATX and HTX. The increasing importance of Tychonema in Lake Garda was also suggested by the opposite trends of ATX and MCs observed since 2009. These results suggest that radical changes are occurring in the largest lakes south of the Alps. Their verification and implications will require to be assessed by extending a complete experimental work to the other large perialpine lakes.

  10. Ecological monitoring for assessing the state of the nearshore and open waters of the Great Lakes

    Science.gov (United States)

    Neilson, Melanie A.; Painter, D. Scott; Warren, Glenn; Hites, Ronald A.; Basu, Ilora; Weseloh, D.V. Chip; Whittle, D. Michael; Christie, Gavin; Barbiero, Richard; Tuchman, Marc; Johannsson, Ora E.; Nalepa, Thomas F.; Edsall, Thomas A.; Fleischer, Guy; Bronte, Charles; Smith, Stephen B.; Baumann, Paul C.

    2003-01-01

    The Great Lakes Water Quality Agreement stipulates that the Governments of Canada and the United States are responsible for restoring and maintaining the chemical, physical and biological integrity of the waters of the Great Lakes Basin Ecosystem. Due to varying mandates and areas of expertise, monitoring to assess progress towards this objective is conducted by a multitude of Canadian and U.S. federal and provincial/state agencies, in cooperation with academia and regional authorities. This paper highlights selected long-term monitoring programs and discusses a number of documented ecological changes that indicate the present state of the open and nearshore waters of the Great Lakes.

  11. Cyanotoxins in Inland Lakes of the United States: Occurrence and Potential Recreational Health Risks in the EPA National Lakes Assessment 2007

    Science.gov (United States)

    A large nation-wide survey or cyanotoxlns (1161 lakes)in the United States (U.S.) was conducted dunng the EPA National Lakes Assessment 2007. Cyanotoxin data were compared with cyanobacteria abundance- and chlorophyll-based World Health Organization (WHO) thresholds and mouse to...

  12. Redundancy in the ecological assessment of lakes: Are phytoplankton, macrophytes and phytobenthos all necessary?

    Science.gov (United States)

    Kelly, Martyn G; Birk, Sebastian; Willby, Nigel J; Denys, Luc; Drakare, Stina; Kahlert, Maria; Karjalainen, Satu Maaria; Marchetto, Aldo; Pitt, Jo-Anne; Urbanič, Gorazd; Poikane, Sandra

    2016-10-15

    Although the Water Framework Directive specifies that macrophytes and phytobenthos should be used for the ecological assessment of lakes and rivers, practice varies widely throughout the EU. Most countries have separate methods for macrophytes and phytobenthos in rivers; however, the situation is very different for lakes. Here, 16 countries do not have dedicated phytobenthos methods, some include filamentous algae within macrophyte survey methods whilst others use diatoms as proxies for phytobenthos. The most widely-cited justification for not having a dedicated phytobenthos method is redundancy, i.e. that macrophyte and phytoplankton assessments alone are sufficient to detect nutrient impacts. Evidence from those European Union Member States that have dedicated phytobenthos methods supports this for high level overviews of lake condition and classification; however, there are a number of situations where phytobenthos may contribute valuable information for the management of lakes. PMID:26904924

  13. Assessing the economic value of protecting artificial lakes

    OpenAIRE

    Halkos, George

    2012-01-01

    This study examines the current and potential economic value of an artificial lake aiming to explore the factors that affect people’s willingness to pay (WTP) for its protection. The WTP was derived from a face-to-face survey of 564 residents and recreational users of the Plastira’s lake, one of the most important constructed wetlands in Greece. We find a higher WTP of individuals towards the lake’s functions and their desire to prevent possible diminutions of its total economic value and we ...

  14. The importance of spatial variation of benthic invertebrates for the ecological assessment of European lakes

    DEFF Research Database (Denmark)

    Solimini, Angelo G.; Sandin, Leif Leonard

    2012-01-01

    Lake assessment systems based on benthic macroinvertebrates critically depend on the amount of spatial variation of organisms within and between lakes. Investigators need to distinguish between community changes that are related to human pressures and those that are caused by inherent natural var...... pressures from the Nordic, Central, Atlantic, Alpine and Mediterranean regions. All papers have an obvious applied objective and suggest which factors need to be considered when designing invertebrate-based classification tools....

  15. Assessing Lake Trophic Status: A Proportional Odds Logistic Regression Model

    Science.gov (United States)

    Lake trophic state classifications are good predictors of ecosystem condition and are indicative of both ecosystem services (e.g., recreation and aesthetics), and disservices (e.g., harmful algal blooms). Methods for classifying trophic state are based off the foundational work o...

  16. Assessments of Water Quality in Mississippi Delta Lake Watersheds

    Science.gov (United States)

    This paper summarizes watershed scale research by USDA-ARS National Sedimentation Laboratory scientists on the effects of conservation management on water quality and ecology in oxbow lakes of the Mississippi Delta Region, USA. The Mississippi Delta Region is located in the central portion of the U...

  17. Lessons learned from Ontario wind energy disputes

    Science.gov (United States)

    Fast, Stewart; Mabee, Warren; Baxter, Jamie; Christidis, Tanya; Driver, Liz; Hill, Stephen; McMurtry, J. J.; Tomkow, Melody

    2016-02-01

    Issues concerning the social acceptance of wind energy are major challenges for policy-makers, communities and wind developers. They also impact the legitimacy of societal decisions to pursue wind energy. Here we set out to identify and assess the factors that lead to wind energy disputes in Ontario, Canada, a region of the world that has experienced a rapid increase in the development of wind energy. Based on our expertise as a group comprising social scientists, a community representative and a wind industry advocate engaged in the Ontario wind energy situation, we explore and suggest recommendations based on four key factors: socially mediated health concerns, the distribution of financial benefits, lack of meaningful engagement and failure to treat landscape concerns seriously. Ontario's recent change from a feed-in-tariff-based renewable electricity procurement process to a competitive bid process, albeit with more attention to community engagement, will only partially address these concerns.

  18. Strategic assessment of the magnitude and impacts of sand mining in Poyang Lake, China

    NARCIS (Netherlands)

    Leeuw, de J.; Shankman, D.; Wu, G.; Boer, de W.F.; Burnham, J.; He, Q.; Yesou, H.; Xiao, J.

    2010-01-01

    Planning for the extraction of aggregates is typically dealt with at a case to case basis, without assessing environmental impacts strategically. In this study we assess the impact of sand mining in Poyang Lake, where dredging began in 2001 after sand mining in the Yangtze River had been banned. In

  19. Direct heat applications of geothermal energy in The Geysers/Clear Lake region. Volume I. Geotechnical assessment, agribusiness applications, socioeconomic assessment, engineering assessment. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1976-08-01

    Discussion is presented under the following section headings: background and some technical characteristics of geothermal resources; geology and geohydrology, geophysics, and, conclusions regarding availability of geothermal energy for nonelectric uses; agricultural assessment of Lake County, site assessment for potential agricultural development, analysis of potential agricultural applications, special application of low cost geothermal energy to algae harvesting, development of an integrated agribusiness, geothermal complex in Lake County, analysis of individual enterprises, and, recommendations for subsequent work; demographic characteristics, economic condition and perspective of Lake County, economic impact of geothermal in Lake County, social and economic factors related to geothermal resource development, socioeconomic impact of nonelectric uses of geothermal energy, and, identification of direct heat applications of geothermal energy for Lake County based on selected interviews; cost estimate procedure, example, justification of procedure, and, typical costs and conclusions; and, recommended prefeasibility and feasibility studies related to construction of facilities for nonelectric applications of geothermal resource utilization. (JGB)

  20. Assessment of the risk of drowning at low-head dams used as sea lamprey barriers in Ontario[Includes the CSCE forum on professional practice and career development : 1. international engineering mechanics and materials specialty conference : 1. international/3. coastal, estuarine and offshore engineering specialty conference : 2. international/8. construction specialty conference

    Energy Technology Data Exchange (ETDEWEB)

    Mazurek, K.A.; Thomson, J.; Amos, M. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Civil and Geological Engineering; Hallett, A. [A. Hallett, Sault Ste. Marie, ON (Canada); Aktar, A. [Indian Inst. of Technology, Kanpur (India). Dept. of Civil Engineering; Katopodis, C. [Fisheries and Oceans Canada, Winnipeg, MB (Canada). Freshwater Inst.

    2009-07-01

    In 2003, there were 54 fixed-crest lamprey barriers used in the Great Lakes region, with more construction planned. Although the barriers are relatively small structures of about 1-2 m in height, they present a drowning hazard. On the downstream side of the structure, a submerged hydraulic jump creates a strong vortex flow that even an experienced swimmer cannot escape. This study developed a method to assess the risk of hazardous flows at the barrier sites to enable dam owners to decide whether or not mitigative measures need to be undertaken at their sites. This hazard assessment was demonstrated for 2 existing lamprey barriers in Ontario, namely the Duffins Creek Barrier at Ajax and the Little Otter Creek Barrier near Straffordville. However, the work can be applied to the dam safety assessment and the development of potential mitigative strategies for drowning at other low-head dams and weirs. A flow-duration curves was developed for each site in order to determine the risk of having a drowning hazard at the barrier sites. In the flow-duration analysis, the percentage time, or probability, that a given flow rate was equalled or exceeded was calculated directly from observations of the average daily discharge in the channel. 18 refs., 1 tab., 7 figs.

  1. Lake breezes in the southern Great Lakes region and their influence during BAQS-Met 2007

    Directory of Open Access Journals (Sweden)

    D. M. L. Sills

    2011-08-01

    Full Text Available Meteorological observations from the BAQS-Met field experiment during the summer months of 2007 were integrated and manually analyzed in order to identify and characterize lake breezes in the southern Great Lakes region of North America, and assess their potential impact on air quality. Lake breezes occurred frequently, with one or more lake breezes identified on 90 % of study days. They affected all parts of the study region, including southwestern Ontario and nearby portions of southeast Lower Michigan and northern Ohio, with lake-breeze fronts occasionally penetrating from 100 km to over 200 km inland. Occurrence rates and penetration distances were found to be higher than previously reported in the literature. This comprehensive depiction of observed lake breezes allows an improved understanding of their influence on the transport, dispersion, and production of pollutants in this region.

    The observational analyses were compared with output from subsequent runs of a high-resolution numerical weather prediction model. The model accurately predicted lake breeze occurrence and type in a variety of synoptic wind regimes, but selected cases showed substantial differences in the detailed timing and location of lake-breeze fronts, and with the initiation of deep moist convection. Knowledge of such strengths and weaknesses aids in the interpretation of results from air quality models driven by this meteorological model.

  2. Toxicity assessment of polycyclic aromatic hydrocarbons in sediments from European high mountain lakes.

    Science.gov (United States)

    Quiroz, Roberto; Grimalt, Joan O; Fernández, Pilar

    2010-05-01

    Sediment quality guidelines and toxic equivalent factors have been used for assessment of the toxicity of sedimentary long-range atmospherically transported polycyclic aromatic hydrocarbons (PAHs) to the organisms living in high mountain European lakes. This method has provided indices that are consistent with experimental studies evaluating in situ sedimentary estrogenic activity or physiological response to AhR binding in fish from the same lakes. All examined lakes in north, central, west, northeast and southeast European mountains have shown sedimentary PAH concentrations that are above thresholds of no effect but only those situated in the southeast lakes district exhibited concentrations above the indices of probable effects. These mountains, Tatras, are also those having PAH concentrations of highest activity for AhR binding. Chrysene+triphenylene, dibenz[a]anthracene, benzo[k]fluoranthene and indeno[1,2,3-cd]pyrene are the main compounds responsible for the observed toxic effects.

  3. Assessing degradation and recovery pathways in lakes impacted by eutrophication using the sediment record

    Directory of Open Access Journals (Sweden)

    Helen eBennion

    2015-08-01

    Full Text Available Efforts to restore enriched lakes have increased yet there remains uncertainty about whether restoration targets can be achieved and over what timescale. Paleoecological techniques, principally diatom analyses, were used to examine the degree of impact and recovery in 12 European lakes subject to eutrophication and subsequent reduction in nutrient loading. Dissimilarity scores showed that all sites experienced progressive deviation from the reference sample (core bottom prior to nutrient reduction, and principal curves indicated gradual compositional change with enrichment. When additive models were applied to the latter, the changes were statistically significant in 9 of the 12 sites. Shifts in diatom composition following reduction in nutrient loading were more equivocal, with a reversal towards the reference flora seen only in four of the deep lakes and one of the shallow lakes. Of these, only two were significant (Lake Bled and Mjøsa. Alternative nutrient sources seem to explain the lack of apparent recovery in the other deep lakes. In three shallow lakes diatom assemblages were replaced by a community associated with lower productivity but not the one seen prior to enrichment. Internal loading and top down control may influence recovery in shallow lakes and climate change may have confounded recovery in several of the study sites. Hence, ecosystem recovery is not simply a reversal of the degradation pathway and may take several decades to complete or, for some lakes, may not take place at all. By assessing ecological change over a decadal to centennial timescale, the study highlights the important role that paleolimnology can play in establishing a benchmark against which managers can evaluate the degree to which their restoration efforts are successful.

  4. Assessing the potential environmental impact of Athabasca oil sands development in lakes across Northwest Saskatchewan

    Science.gov (United States)

    Ahad, J. M.; Cumming, B. F.; Das, B.; Sanei, H.

    2011-12-01

    The continued development of Canada's Athabasca oil sands poses a significant environmental challenge. Low buffered boreal lakes located downwind of the prevailing eastward wind direction may be threatened by acidification and elevated inputs of airborne contaminants such as polycyclic aromatic hydrocarbons (PAHs). An accurate assessment of the impact that increased levels of bitumen production may have on lakes in the region requires an understanding of the historic variability within these systems prior to at least the past several decades. Here we report concentrations of PAHs, δ13C and δ15N of organic matter (OM), Rock-Eval pyrolysis analyses, and distributions of n-alkanes in dated sediment cores from ten lakes located across NW Saskatchewan. Concentrations of PAHs were relatively low (fires as a principal PAH source. Plots of Hydrogen Index (HI) versus Oxygen Index (OI) fell within a relatively narrow range typical for sediments containing a high content of algal-derived OM. Relatively lower C/N ratios and higher abundances of C17 n-alkane in more recent sediments pointed to an increasingly larger component of algal-derived OM. In all ten lakes δ13C showed gradual upcore depletions that fell within the expected range for fossil fuel combustion (i.e., Suess effect), although this alone may not explain the up to ~3% depletion observed in several of the lakes. In conjunction with the other upcore trends these data may suggest a possible increase in primary productivity over the past several decades in many of the lakes studied. δ15N signatures were more variable, showing upcore increases in some lakes and upcore depletions in others. The increasingly lighter values observed in more recent sediments in some lakes suggest a potential input of depleted bioavailable nitrogen, as might be expected from anthropogenic NOx emissions. This study implies that thus far it appears that oil sands industry related emissions have had only a minor environmental impact on

  5. Environment for Development: An Ecosystems Assessment of Lake Victoria Basin.

    OpenAIRE

    Karanja, D.M.S

    2006-01-01

    The extent to which the pressures on the Lake Victoria basin environment impact the health and nutrition of the communities within the region is often not adequately addressed. The burden of diseases and constraints on the health facilities in basin can be traced to the state of the environment, vulnerabilities of communities and livelihood strategies. Predominant health issues in the basin are linked to unsafe water contaminated by microbial and chemical pollutants, poor disposal of human wa...

  6. Contamination and Risk Assessment of Heavy Metals in Lake Bed Sediment of a Large Lake Scenic Area in China

    Science.gov (United States)

    Wan, Li; Xu, Liang; Fu, Yongsheng

    2016-01-01

    The exposure of heavy metals to lake bed sediment of scenic areas may pose risks on aquatic ecosystems and human health, however very few studies on risk assessment have been reported for scenic areas. Accordingly, this study determined concentration levels, and assessed contamination characteristics and risks, of heavy metals in lake bed sediment of National Scenic Areas Songhuahu (NSAS) in China. The concentrations of Zn, Cr, Pb, Ni, and Cu were determined in 29 bed sediment samples. Results showed that the mean values of Zn, Cr, Pb, Ni, and Cu were 92.69, 90.73, 38.29, 46.77, and 49.44 mg/kg, respectively. Pearson correlation coefficients indicated that organic matter was a major factor influencing distribution of heavy metals. The results for enrichment factors indicated that contamination rates and anthropogenic inputs of single heavy metals decreased in the order Cu > Ni > Pb > Cr > Zn; results of Nemerow integrated pollution index suggested that 72.41% of sampling sites were exposed to low to moderately integrated pollution, and 27.59% of sampling sites were exposed to strongly integrated pollution. According to results for potential ecological risk index, ecological risks of single and all the heavy metals in bed sediment from all the sampling sites were low. Human risks were assessed with hazardous quotients, and the results suggested that exposure of heavy metals to bed sediment posed no or little risk to human health, and the pathway of ingestion significantly contributed to human health risks. PMID:27455296

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

    International Nuclear Information System (INIS)

    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

  8. 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.

  9. Ontario's energy action plan

    International Nuclear Information System (INIS)

    In the fall of 2002, the government of Ontario announced an action plan designed to ensure stable electricity prices while additional electricity generating capacity is built. The action plan included a strategy for encouraging major private sector investments in wind, solar and other renewable energy sources. The strategies for new renewable energy projects include: property tax incentives, business income tax incentives, and sales tax rebates. Initiatives to increase supply include: Toronto's Portland 550 megawatt, natural gas-fired generating station, Niagara Falls' Beck Tunnel Project, and Windsor's 580 megawatt natural gas-fired generating station. The government is promoting energy conservation by reducing its electricity consumption by 10 per cent, and setting a target where 20 per cent of electricity consumed in the province must be from renewable energy sources. The use of interval meters by Ontario residents is being encouraged. A provincial sales tax rebate is being offered to customers buying select energy efficient appliances. In its commitment to environmental protection, the Ontario government is phasing out coal, offering rebates for solar energy systems, implementing measures to reduce acid rain, and investing $3.25 billion over ten years to renew and expand public transit. In Chatham, Ontario, a plant producing ethanol from corn was built, and others are planned for other parts of the province. Tax incentives are also offered for alternative fuel users. 1 ref., 1 tab

  10. Lake Diefenbaker: Water Quality Assessment and Modeling for Management under Environmental Change

    Science.gov (United States)

    Sereda, J.; Wheater, H. S.; Hudson, J.; Doig, L.; Liber, K.; Jones, P.; Giesy, J.; Bharadwaj, L.

    2011-12-01

    Preliminary results are presented for a comprehensive inter-disciplinary study on Lake Diefenbaker initiated by the Global Institute for Water Security to understand the physical and biogeochemical processes affecting water quality under climate change and their policy implications. Lake Diefenbaker is a large reservoir (surface area ~500km2 and Zmean ~33m) located in Southern Saskatchewan, Canada and is a critically-important water resource for Saskatchewan. It receives nearly all of its flow from the South Saskatchewan River, which flows through some of the most urbanized and intense agricultural lands of southern Alberta. As a result these waters contain high levels of nutrients [nitrogen (N) and phosphorus (P)] along with a variety of chemical contaminants characteristic of anthropogenic activity. In addition, riparian and in-lake activities provide local sources of nutrients, from domestic sewage, agriculture and fish farming. The South Saskatchewan River has been identified by the World Wildlife Fund (2009) as Canada's most threatened river in terms of environmental flow. Lake Diefenbaker has numerous large deep embayments (depth >20m) and an annual water level fluctuation of ~6m. A deep thermocline (~25m) forms infrequently. Stratification does not occur throughout the lake. Anecdotal information suggests that the frequency and severity of algal blooms are increasing; although blooms have been sporadic and localized. This localized eutrophication may be related to local stratification patterns, point source nutrient loading, and/or internal lake processes (i.e., internal nutrient loading). A paleolimnological reconstruction has begun to assess historical nutrient and contaminant loading to Lake Diefenbaker and hence the trajectory of water quality in the lake. Major point sources and diffuse sources of N and P are also under investigation. In addition, the type (N versus P) and degree of nutrient limitation of bacteria and algae are being assessed (spatially

  11. Phytoplankton recovery from acid and metal contamination : a comparison of limed and unmanipulated lakes

    Energy Technology Data Exchange (ETDEWEB)

    Winter, J.G [Ontario Ministry of Environment, Toronto, ON (Canada). Environmental Monitoring and Reporting Branch; Keller, W. [Laurentian Univ., Sudbury, ON (Canada). Cooperative Freshwater Ecology Unit; Paterson, A.M. [Ontario Ministry of Environment, Dorset, ON (Canada). Dorset Environmental Science Centre; Yan, N.D. [York Univ., Toronto, ON (Canada). Dept. of Biology

    2007-07-01

    In order to assess biological recovery from acidification, as well as differences in community composition between manipulated and un-manipulated lakes, a study was conducted to investigate the long-term changes in the phytoplankton communities of four lakes (Clearwater Lake, Middle Lake, Hannah Lake, and Lohi Lake) located within 15 km of Sudbury, Ontario, an area significantly damaged by sulphur dioxide and metals from local smelter emissions. The study compared changes in the phytoplankton communities in the lakes over the last two to three decades, and evaluated them against data collected since 1980 from reference lakes within the same biogeographic region but beyond the influence of the Sudbury smelters. The paper provided background on emissions and biological recovery in the area as well as on the results of the study. It was concluded that there was evidence of recovery in the composition of phytoplankton communities of the acidified lakes over the last 30 years given the shift in their composition towards those of the reference lakes. In addition, the recovery of the un-limed lakes was more gradual than in the limed lakes, occurring over a period of 25 years. 2 refs., 1 fig.

  12. Water quality monitoring and assessment of an urban Mediterranean lake facilitated by remote sensing applications.

    Science.gov (United States)

    Markogianni, V; Dimitriou, E; Karaouzas, I

    2014-08-01

    Degradation of water quality is a major problem worldwide and often leads to serious environmental impacts and concerns about public health. In this study, the water quality monitoring and assessment of the Koumoundourou Lake, a brackish urban shallow lake located in the northeastern part of Elefsis Bay (Greece), were evaluated. A number of water quality parameters (pH, temperature, dissolved oxygen concentration, electrical conductivity, turbidity, nutrients, and chlorophyll-a concentration) were analyzed in water samples collected bimonthly over a 1-year period from five stations throughout the lake. Moreover, biological quality elements were analysed seasonally over the 1-year period (benthic fauna). Statistical analysis was performed in order to evaluate the water quality of the lake and distinguish sources of variation measured in the samples. Furthermore, the chemical and trophic status of the lake was evaluated according to the most widely applicable classification schemes. Satellite images of Landsat 5 Thematic Mapper were used in order for algorithms to be developed and calculate the concentration of chlorophyll-a (Chl-a). The trophic status of the lake was characterized as oligotrophic based on phosphorus and as mesotrophic-eutrophic based on Chl-a concentrations. The results of the remote sensing application indicated a relatively high coefficient of determination (R (2)) among point sampling results and the remotely sensed data, which implies that the selected algorithm is reliable and could be used for the monitoring of Chl-a concentration in the particular water body when no field data are available.

  13. Spatial distribution and pollution assessment of mercury in sediments of Lake Taihu, China

    Institute of Scientific and Technical Information of China (English)

    Chunxiao Chen; Binghui Zheng; Xia Jiang; Zheng Zhao; Yuzhu Zhan; Fengjiao Yi; Jiaying Ren

    2013-01-01

    Spatial distribution patterns of total mercury (THg) in 36 surficial sediment samples representing five regions of Lake Taihu were assessed using the ArcGis geostatistical analyst module.The pollution levels of THg were also evaluated from the same five lake regions.Concentrations of THg were in a ranged of 23-168 ng/g (mean 55 ng/g) in surfical sediments,which was significantly higher than those established baseline levels of the lake.Results of THg indicated that the northern region exhibited notably higher values,the bay regions showed elevated values relative to open areas,and the lakeside regions were higher than those observed in the central area.Lake Taihu suffered moderate to high Hg pollution,and expressed clear Hg enrichment status according to monomial pollution index Igeo and human activity factors.The concentrations of THg in the surticial sediments of Lake Taihu showed moderate-strong variation (coefficient of variation 52%).Geostatistical analysis indicated a weak spatial self-correlation,suggesting the contamination of Hg in Lake Taihu is primarily the result of anthropogenic activities.

  14. Expanding exports, increasing smog : Ontario Power Generation's and Hydro One's strategies to continue coal-fired electricity generation in Ontario

    International Nuclear Information System (INIS)

    The production of coal-fired electricity increased by approximately 150 per cent in Ontario between 1995 and 2000. As a result, the smog-causing emissions generated by the five coal-fired power plants operated by Ontario Power Generation caused an increase in smog and worsened air quality in the province as well as affecting air quality as far afield as the Atlantic provinces. Between 2002 and 2005, it is expected that the Pickering and Bruce nuclear plants will be returned to service, making the electricity generated by the coal plants surplus to Ontario's needs. Increasing this surplus are the planned natural gas generating stations. Ontario Power Generation is planning on using this surplus to export it to the United States rather than phasing out its reliance on coal. The increase in exports to the United States Northeast and Midwest is planned with Hydro One, already busy increasing its transmission capacity to the United States by 1,000 megawatt (MW). This plan involves laying 975 MW submarine cable from the Nanticoke Generating Station (operated by Ontario Power Generation) under Lake Erie to Pennsylvania, Ohio, or both states. At the moment, the exports are constrained by the government emissions limits imposed by the Ontario government on sulphur dioxide and nitrogen oxides. This constraint could be removed if Ontario Power Generation decides to pay further for pollution controls for sulphur dioxide and nitrogen oxides at its coal stations. Unfortunately, increasing the exports would also result in emissions increases for 28 other uncapped pollutants such as lead, mercury and arsenic. The author recommended that the Ontario government ban non-emergency coal-fired electricity exports to improve air quality in the province. refs., 8 figs

  15. Wind power and bats : Ontario guideline

    Energy Technology Data Exchange (ETDEWEB)

    McGuiness, F. [Ontario Ministry of Natural Resources, Peterborough, ON (Canada). Renewable Energy Resources; Stewart, J. [Ontario Ministry of Natural Resources, Toronto, ON (Canada). Wildlife Section

    2008-07-01

    None of the 8 species of bats in Ontario are considered as species at risk. However, all bats in Ontario are protected under the Fish and Wildlife Conservation Act. The Ontario Ministry of Natural Resources (MNR) is responsible for identifying significant wildlife habitat for bats, including hibernacula and maternity roosts. The MNR's role in wind development includes environmental assessments (EA) and surveys. The MNR bat guideline includes a summary of Ontario species, a literature review of research related to wind turbines and bats, and a review of methods for assessing and monitoring bats. Guideline development includes a bat working group responsible for obtaining data on risk factors and monitoring requirements. The MNR has determined that site selection is critical for minimizing potential impacts. Wind farm proponents can use MNR data, information, and maps for their site selection process. Information requirements include bat species data; habitat data; and meteorological data. The presence of risk factors results in a sensitivity rating. The MNR is also developing a site sensitivity mapping project in order to assist proponents in making siting decisions. All proposed sites are required to conduct pre-construction site surveys. Acoustic detectors and radar are used to determine bat activity at the site. Monitoring and mitigation strategies include selective wind turbine shutdown during key periods or weather conditions. tabs., figs.

  16. Detecting river sediments to assess hazardous materials at volcanic lake using advanced remote sensing techniques

    Science.gov (United States)

    Saepuloh, Asep; Fitrianingtyas, Chintya

    2016-05-01

    The Toba Caldera formed from large depression of Quaternary volcanism is a remarkable feature at the Earth surface. The last Toba super eruptions were recorded around 73 ka and produced the Youngest Toba Tuff about 2,800 km3. Since then, there is no record of significant volcanic seismicity at Toba Volcanic Complex (TVC). However, the hydrothermal activities are still on going as presented by the existence of hot springs and alteration zones at the northwest caldera. The hydrothermal fluids probably containing some chemical compositions mixed with surficial water pollutant and contaminated the Toba Lake. Therefore, an environmental issues related to the existence of chemical composition and degradation of water clearness in the lake had been raised in the local community. The pollutant sources are debatable between natural and anthropogenic influences because some human activities grow rapidly at and around the lake such as hotels, tourisms, husbandry, aquaculture, as well as urbanization. Therefore, obtaining correct information about the source materials floating at the surface of the Toba Lake is crucial for environmental and hazard mitigation purposes. Overcoming the problem, we presented this paper to assess the source possibility of floating materials at Toba Lake, especially from natural sources such as hydrothermal activities of TVC and river stream sediments. The Spectral Angle Mapper (SAM) techniques using atmospherically corrected of Landsat-8 and colour composite of Polarimetric Synthetic Aperture Radar (PolSAR) were used to map the distribution of floating materials. The seven ground truth points were used to confirm the correctness of proposed method. Based on the SAM and PolSAR techniques, we could detect the interface of hydrothermal fluid at the lake surfaces. Various distributions of stream sediment were also detected from the river mouth to the lake. The influence possibilities of the upwelling process from the bottom floor of Toba Lake were also

  17. Current chemical exposures among Ontario construction workers.

    Science.gov (United States)

    Verma, Dave K; Kurtz, Lawrence A; Sahai, Dru; Finkelstein, Murray M

    2003-12-01

    Current occupational exposures to chemical agents were assessed as part of an epidemiological study pertaining to the cancer and mortality patterns of Ontario construction workers. The task-based exposure assessment involved members from nine construction trade unions. Air samples were taken using personal sampling pumps and collection media. A DustTrak direct-reading particulate monitor was also employed. Exposure assessments included measurements of airborne respirable, inhalable, total, and silica dust; solvents; metals; asbestos; diesel exhaust and man-made mineral fibers (MMMF). In total, 396 single- or multi-component (filter/tube), 798 direct-reading, and 71 bulk samples were collected. The results showed that Ontario construction workers are exposed to potentially hazardous levels of chemical agents. The findings are similar to those reported by other researchers, except for silica exposure. In our study, silica exposure is much lower than reported elsewhere. The difficulty associated with assessing construction workers' exposures is highlighted. PMID:14612300

  18. Assessing element-specific patterns of bioaccumulation across New England lakes

    International Nuclear Information System (INIS)

    improve our capacity to identify consistent patterns of bioaccumulation and drivers of elevated trace element concentrations under naturally high levels of variability. - Highlights: ► We assessed bioaccumulation of MeHg and 5 trace elements across trophic levels ► Patterns were compared across multiple sample dates in 7 New England lakes ► Each element had a unique pattern of bioaccumulation, consistent across lakes ► Characterizing such patterns requires spatial and temporal replication in sampling

  19. Assessing element-specific patterns of bioaccumulation across New England lakes

    Energy Technology Data Exchange (ETDEWEB)

    Ward, Darren M.; Mayes, Brandon; Sturup, Stefan; Folt, Carol L.; Chen, Celia Y., E-mail: celia.chen@dartmouth.edu

    2012-04-01

    improve our capacity to identify consistent patterns of bioaccumulation and drivers of elevated trace element concentrations under naturally high levels of variability. - Highlights: Black-Right-Pointing-Pointer We assessed bioaccumulation of MeHg and 5 trace elements across trophic levels Black-Right-Pointing-Pointer Patterns were compared across multiple sample dates in 7 New England lakes Black-Right-Pointing-Pointer Each element had a unique pattern of bioaccumulation, consistent across lakes Black-Right-Pointing-Pointer Characterizing such patterns requires spatial and temporal replication in sampling.

  20. Assessing the impacts of Three Gorges Dam on lake inundation areas across the downstream Yangtze floodplain

    Science.gov (United States)

    Wang, J.; Sheng, Y.; Wada, Y.

    2013-12-01

    China's Three Gorges Dam (TGD) has received worldwide attention due to its profound impacts on the downstream hydraulic, morphological, and ecological systems. The TGD operation results in direct alternation of the discharge to the middle and lower Yangtze reach, manifested as regulated flow and reduced sediment load. TGD's flow regulation, typically described as water storage in fall while release in winter and spring, interferes with the natural seasonality of downstream Yangtze River levels which are essentially important to the inundation dynamics of surrounding lakes/wetlands in the Yangtze floodplain. Concurrent decrease of sediment load has caused chronic downstream channel erosion which lowers Yangtze level in relation to flow and further affects the sustainability of riparian lakes and the related ecosystems. By integrating satellite observations, in situ measurement, and hydrologic simulations, this study presents a systematic assessment of the TGD impacts on the inundation areas of six major freshwater lakes across the entire Yangtze basin downstream of the TGD, during the time period from TGD's initial impoundment in June 2003 to early 2012. Despite the small number, the six targeted lakes cover a total area of ~5,000 km2 accounting for ~25% of the freshwater lake area in China, and were identified as the only natural lakes that remain in open connection to the Yangtze River across the downstream floodplain. Using daily MODIS imagery from 2000 to 2012, we revealed a significant year-round decline in the aggregated inundation area of the studied lakes by an average of ~580 km2 or 17.7% from the pre-dam to post-dam period (i.e., before and after June, 2003). To diagnose TGD's contribution to such lake area decline, we followed a two-step procedure by first quantifying the TGD impacts on the seasonal level regime along the complete longitudinal range of the Yangtze River downstream from TGD to the estuary [Wang et al., 2013], and then estimating the

  1. OVERVIEW OF THE MARK TWAIN LAKE/SALT RIVER BASIN CONSERVATION EFFECTS ASSESSMENT PROJECT

    Science.gov (United States)

    The Mark Twain Lake/Salt River Basin was selected as one of 12 USDA-Agricultural Research Service benchmark watersheds for the Conservation Effects Assessment Project (CEAP) because of documented soil and water quality problems and broad stakeholder interest. The basin is located in northeastern Mis...

  2. Assessing Sediment Yield for Selected Watersheds in the Laurentian Great Lakes Basin Under Future Agricultural Scenarios

    Science.gov (United States)

    In the Laurentian Great Lakes Basin (GLB), corn acreage has been expanding since 2005 in response to high demand for corn as an ethanol feedstock. This study integrated remote sensing-derived products and the Soil and Water Assessment Tool (SWAT) withing a GIS modeling environme...

  3. Shoreline features of Titan's Ontario Lacus from Cassini/VIMS observations

    Science.gov (United States)

    Barnes, J.W.; Brown, R.H.; Soderblom, J.M.; Soderblom, L.A.; Jaumann, R.; Jackson, B.; Le, Mouelic S.; Sotin, C.; Buratti, B.J.; Pitman, K.M.; Baines, K.H.; Clark, R.N.; Nicholson, P.D.; Turtle, E.P.; Perry, J.

    2009-01-01

    We analyze observations of Titan's south polar lake Ontario Lacus obtained by Cassini's Visual and Infrared Mapping Spectrometer during the 38th flyby of Titan (T38; 2007 December 5). These near-closest-approach observations have the highest signal-to-noise, the finest spatial resolution, and the least atmospheric influence of any near-infrared lake observation to date. We use the large, spatially flat, and low-albedo interior of Ontario Lacus as a calibration target allowing us to derive an analytical atmospheric correction for emission angle. The dark lake interior is surrounded by two separate annuli that follow the lake interior's contours. The inner annulus is uniformly dark, but not so much as the interior lake, and is generally 5-10 kilometers wide at the lake's southeastern margin. We propose that it represents wet lakebed sediments exposed by either tidal sloshing of the lake or seasonal methane loss leading to lower lake-volume. The exterior annulus is bright and shows a spectrum consistent with a relatively low water-ice content relative to the rest of Titan. It may represent fine-grained condensate deposits from a past era of higher lake level. Together, the annuli seem to indicate that the lake level for Ontario Lacus has changed over time. This hypothesis can be tested with observations scheduled for future Titan flybys. ?? 2008 Elsevier Inc.

  4. Environmental Assessments of Trace Metals in Sediments from Dongting Lake, Central China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    To examine the degree of contamination in the Dongting Lake (洞庭湖) area, surface sediments samples were collected and investigated in this study.This lake lies in the south of the middle Yangtze River, and it is the second largest fresh-water lake in China.These samples were analyzed for the concentrations of the following 6 elements (Cd, Cr, Cu, Ni, Pb and Zn) collected from 46 locations.The index of geo-accumulation was used to assess the degree of contamination of the total trace elements and the assessments showed that the contamination of Cd reached strong to very strong pollution.The speciation of metal in sediments was analyzed using the modified BCR (Community Bureau of Reference) sequential extraction technology and the water column-contamination risk was evaluated by the calculated contamination factors.The results of the speciation of metal indicated that more easily mobilized forms(exchangeable, water soluble, and acid soluble) were predominant for Cd, especially in the samples from East Dongting Lake.In contrast, the largest amount of lead was associated with the iron and manganese oxide fractions, and Cu, Zn, Cr, and Ni analyzed were mainly distributed in residual phase at an average percentage higher than 60 % of the total metals.The potential risk to the lake's water contamination was the highest in East Dongting Lake based on the calculated contamination factors.The assessment results using geo-accumulation index were compared with the information obtained by trace metal speciation and both results were consistent.

  5. Assessing the controls of the snow energy balance in a shrub-covered bog in eastern Ontario, Canada

    Science.gov (United States)

    Carey, S. K.; Knox, S.; Humphreys, E.

    2012-12-01

    The objectives of this study were to measure and evaluate the energy balance of a snowpack in a northern peatland, with a particular emphasis on the ground heat flux (G), and to evaluate the performance of a point energy and mass balance snowmelt model (SNOBAL) in peatland ecosystems. G is typically considered a small component of the snowpack energy balance (EB) when compared with radiative and turbulent fluxes. However, in environments where the soil temperature remains above freezing throughout the winter, G may be an important energy input to the snowpack. For direct assessment of the role of G in the snow energy budget of such an environment, the EB components of the snowpack at the Mer Bleue bog, a northern peatland, were directly measured and modelled using SNOBAL during the 2009-2010 winter. An 8 m tower mounted with a net radiometer, closed-path eddy covariance system, and supporting hydrometeorological instruments were used to quantify each form of energy transfer to the snowpack. In addition, snow surveys were conducted to determine snow depth, density, and snow water equivalent. When integrated over the pre-melt period, simulated and measured G proved to be a large contributor to the EB (25%). Net radiation and G were somewhat under-predicted by SNOBAL, whereas turbulent fluxes (especially latent heat fluxes, LE) were considerably over-predicted. G calculated by SNOBAL was found to be sensitive to the temperature gradient between the soil and the lower layer of the snowpack, whereas simulated turbulent fluxes were sensitive to the parameterization chosen to estimate roughness lengths for heat and water vapour.

  6. Assessment of Water and Sediment Physical-Chemical Composition in the West Coast of Maracaibo Lake

    Directory of Open Access Journals (Sweden)

    Jorge Moronta-Riera

    2016-05-01

    Full Text Available The objective of this investigation was to determine the physical and chemical composition of the water streams and sediments of the Maracaibo Lake in three sampling areas located in Tía Juana, Lagunillas and Ceuta in order to know the level of contamination and assess water quality based on permissible values established by the 883 Decree. The results indicate that the overall hydrocarbon concentrations in the water and sediments are above permissible levels. It is concluded that petroleum prospection is the root cause of the lake contamination.

  7. Assessment of water pollution control strategies: a case study for the Dianchi Lake

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Lake eutrophication has increasingly become a major environmental issue in China. Although significant efforts have been made towards its resolution in the last decade, most of the implemented control strategies are fragmented, and the formation of policy lacks of sound scientific basis and long-term objectives. Taking the well-known Dianchi Lake as a case study, this paper presented a comprehensive assessment for the effectiveness of various eutrophication control strategies. It is expected that the concluding lessons would have a major implication to future eutrophication control.

  8. Assessment of the sources of chemical elements in sediment from Arak Mighan Lake

    Institute of Scientific and Technical Information of China (English)

    Feridon GHADIMI

    2014-01-01

    Five sediment zones (20 samples) were collected in Mighan Lake, near Arak city in Markazi province, and were analyzed to reveal element sources and assess the quality of metal contamination. Both anthropogenic and natural origins were identified by correlation, factor, and cluster analyse. According to the enrichment factors (EF) of trace metals (Ba, Co, Cr, Cu, Ni, Pb, Rb, Sr, Zr, and Zn), three groups were identified. Enriched trace elements included: Ni, Zn, and Sr. Comparisons with contamination degree and benchmark sediment quality criteria and guidelines showed that Mighan Lake has potential for adverse effects on aquatic biota because of Ni, Zn, and Cr.

  9. Rotifer community structure and assessment of water quality in Yangcheng Lake

    Institute of Scientific and Technical Information of China (English)

    CHEN Lijing; LIU Qiao; PENG Ziran; HU Zhongjun; XUE Junzeng; WANG Wu

    2012-01-01

    Rotifer community structure was investigated in Yangcheng Lake in 2008.Dominant species and species diversity indices were determined and QB/T was used to assess water quality.The annual average density and biomass of the rotifers in Yangcheng Lake was 2 894± 1 006 ind./L and 12.47± 10.28 mg/L,respectively.The highest densities were observed in the western portion of the lake in March,but the highest biomass occurred in inflowing creeks in September.Within a year of monitoring in Yangcheng Lake,93 species were identified and the dominant species were found to be Polyarthra trigla,Brachionus angularis,Keratella cochlearis,Keratella valga,Brachionus calyciflorus,and Filinia major.Of the species recorded,75 were pollution indicator species.Density and biomass exhibited significant positive correlations with water temperature (R=0.209,P=0.003; R=0.446,P=0.000),but the peak density showed two lags in response to chl a.According to the Jaccard similarity index (SJ),the greatest similarity among dominant species occurred between creeks and the eastern part of the lake.The annual average Shannon-Wiener diversity index H',Margalef richness index D and Pielou evenness index J were 1.96±0.34,1.61 ±0.50and 0.77±0.10,respectively.In all four areas of Yangcheng Lake,β- mesosaprobic species comprised the largest share of pollution indicator species.These data suggest that Yangcheng Lake is mesosaprobic.

  10. Monitoring and assessment of a eutrophicated coastal lake using multivariate approaches

    Directory of Open Access Journals (Sweden)

    U.G. Abhjna

    2016-05-01

    Full Text Available Multivariate statistical techniques such as cluster analysis, multidimensional scaling and principal component analysis were applied to evaluate the temporal and spatial variations in water quality data set generated for two years (2008-2010 from six monitoring stations of Veli-Akkulam Lake and compared with a regional reference lake Vellayani of south India. Seasonal variations of 14 different physicochemical parameters analyzed were as follows: pH (6.42-7.48, water temperature (26.0-31.28°C, salinity (0.50-26.81 ppt, electrical conductivity (47-20656.31 µs/cm, dissolved oxygen (0.078-7.65 mg/L, free carbon-dioxide (3.8-51.8 mg/L, total hardness (27.20-2166.6 mg/L, total dissolved solids (84.66-4195 mg/L, biochemical oxygen demand (1.57-25.78 mg/L, chemical oxygen demand (5.35-71.14 mg/L, nitrate (0.012-0.321 µg/ml, nitrite (0.24-0.79 µg/ml, phosphate (0.04-5.88 mg/L, and sulfate (0.27-27.8 mg/L. Cluster analysis showed four clusters based on the similarity of water quality characteristics among sampling stations during three different seasons (pre-monsoon, monsoon and post-monsoon. Multidimensional scaling in conjunction with cluster analysis identified four distinct groups of sites with varied water quality conditions such as upstream, transitional and downstream conditions  in Veli-Akkulam Lake and a reference condition at Vellayani Lake. Principal Component Analysis showed that Veli-Akkulam Lake was seriously deteriorated in water quality while acceptable water quality conditions were observed at reference lake Vellayani. Thus the present study could estimate the effectiveness of multivariate statistical approaches for assessing water quality conditions in lakes.

  11. Assessment of spatio-temporal variability of lake water color from satellite data

    Science.gov (United States)

    Brivio, Pietro A.; Zilioli, Eugenio

    1995-11-01

    This paper presents a method of satellite remote sensing data analysis for comparative evaluation of inland waters optical quality, which would not necessarily require any in situ measurements. Remote sensing parameters were extracted by digital analysis of two Landsat Thematic Mapper images corresponding to different seasonal situations. The experiment was carried out on the Lake Garda, Italy), where distinct sub-basins can be individuated either for morphological stand-point or for their different water conditions. Subsurface irradiance reflectance values and chromaticity coordinates were derived from radiometric transects covering the different waters from the lake margin to the pelagic environment, and used to assess both spatial pattern and seasonal dynamics of the lake water quality.

  12. Heavy metal bioaccumulation and health hazard assessment for three fish species from Nansi Lake, China.

    Science.gov (United States)

    Li, Pengfei; Zhang, Jian; Xie, Huijun; Liu, Cui; Liang, Shuang; Ren, Yangang; Wang, Wenxing

    2015-04-01

    Metal accumulation in fish is a global public health concern, because the consumption of contaminated fish accounts for the primary exposure of humans to toxic metals. In this study, the concentrations of arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg) in Crucian carp (Carassius auratus),Yellow catfish (Pelteobagrus fulvidraco), and Bighead carp (Hypophthalmichthys nobilis) from Nansi Lake of China were evaluated, and compared with the corresponding historical values in 2001 when the government started to govern water environment effectively. Bioaccumulation of heavy metal was highest in P.fulvidraco, followed by C.auratus and H.nobilis. The concentrations of Pb, As, Cd were much lower than the historical values, but Hg concentration was higher, suggesting that heavy metal pollution problem in fish from Nansi Lake still exists. Health hazard assessment showed no health risk from exposure to Pb, As, Cd, and Hg by consuming fish from this lake. PMID:25636438

  13. Landscape ecological assessment and eco-tourism development in the South Dongting Lake Wetland, China.

    Science.gov (United States)

    He, Ping; Wang, Bao-zhong

    2003-03-01

    As an important resource and the living environment of mankind, wetland has become gradually a highlight, strongly concerned and intensively studied by scientists and sociologists. The governments in the world and the whole society have been paying more and more attention on it. The Dongting Lake of China is regarded as an internationally important wetland. For a rational development and protection of the wetland, an investigation and studied on its resources and its value to tourism in the South Dongting Lake was conducted, to create an assessment system of the ecological landscapes, and to evaluate qualitatively and quantitatively the value of wetland landscape to the ecotourism. The results showed that the scenic value of the South Dongting Lake Wetland satisfied the criterion of AAAA grade of China national scenic attraction. The eco-tourism value of the landscape cultures in the South Dongting Lake Wetland was discussed with emphasis. It were formulated that a principle and frame of sustainable exploitation of the wetland landscapes and it was proposed as well that establishing a Wetland Park and developing eco-tourism in the South Dongting Lake Wetland is a fragile ecosystem with low resistance to the impact of the exploitation. Thus, we must pay intensively attention to the influence of exploitation on the landscape, take the ecological risk in account to employ a right countermeasure and avoid the negative affection.

  14. Ontario Hydro annual report 1985

    International Nuclear Information System (INIS)

    Ontario Hydro is a corporation without share capital created by a special statute of the Province of Ontario in 1906. It now operates under the authority of the Power Corporation Act, R.S.O. 1980, Chapter 384, as amended, with broad powers to generate, supply and deliver electric power throughout the province. It is also authorized to produce and sell steam and hot water as primary products. The Corporation's prime objective is to supply the people of Ontario with electricity at the lowest feasible cost consistent with high safety and quality of service standards. Ontario Hydro's main activity is wholesaling electric power to municipal utilities in urban areas who, in turn, retail it to customers in their service areas. In 1985, approximately 3,166,000 customers were served by Ontario Hydro and the municipal utilities in the province. Ontario Hydro operates 81 hydraulic, fossil and nuclear generating stations and an extensive power grid across Ontario to meet the province's demands for electric energy. Interconnections with other systems place the Corporation in an extensive electrical grid that covers a large segment of the North American continent. Ontario Hydro is a financially self-sustaining corporation. The Province of Ontario guarantees bonds and notes issued to the public by the Corporation

  15. A freshwater biodiversity hotspot under pressure - assessing threats and identifying conservation needs for ancient Lake Ohrid

    Science.gov (United States)

    Kostoski, G.; Albrecht, C.; Trajanovski, S.; Wilke, T.

    2010-12-01

    Immediate conservation measures for world-wide freshwater resources are of eminent importance. This is particularly true for so-called ancient lakes. While these lakes are famous for being evolutionary theatres, often displaying an extraordinarily high degree of biodiversity and endemism, in many cases these biota are also experiencing extreme anthropogenic impact. Lake Ohrid, a major European biodiversity hotspot situated in a trans-frontier setting on the Balkans, is a prime example for a lake with a magnitude of narrow range endemic taxa that are under increasing anthropogenic pressure. Unfortunately, evidence for a "creeping biodiversity crisis" has accumulated over the last decades, and major socio-political changes have gone along with human-mediated environmental changes. Based on field surveys, monitoring data, published records, and expert interviews, we aimed to (1) assess threats to Lake Ohrids' (endemic) biodiversity, (2) summarize existing conservation activities and strategies, and (3) outline future conservation needs for Lake Ohrid. We compiled threats to both specific taxa (and in cases to particular species) as well as to the lake ecosystems itself. Major conservation concerns identified for Lake Ohrid are: (1) watershed impacts, (2) agriculture and forestry, (3) tourism and population growth, (4) non-indigenous species, (5) habitat alteration or loss, (6) unsustainable exploitation of fisheries, and (7) global climate change. Among the major (well-known) threats with high impact are nutrient input (particularly of phosphorus), habitat conversion and silt load. Other threats are potentially of high impact but less well known. Such threats include pollution with hazardous substances (from sources such as mines, former industries, agriculture) or climate change. We review and discuss institutional responsibilities, environmental monitoring and ecosystem management, existing parks and reserves, biodiversity and species measures, international

  16. Periodic structures of Great Lakes levels using wavelet analysis

    OpenAIRE

    Cengiz, Taner M.

    2011-01-01

    The recently advanced approach of wavelet transforms is applied to the analysis of lake levels. The aim of this study is to investigate the variability of lake levels in four lakes in the Great Lakes region where the method of continuous wavelet transform and global spectra are used. The analysis of lake-level variations in the time-scale domain incorporates the method of continuous wavelet transform and the global spectrum. Four lake levels, Lake Erie, Lake Michigan, Lake Ontario, and Lake S...

  17. Development and application of sedimentary pigments for assessing effects of climatic and environmental changes on subarctic lakes in northern Sweden

    DEFF Research Database (Denmark)

    Reuss, Nina Steenberg; Leavitt, Peter R.; Hall, Roland I.;

    2010-01-01

    A surface-sediment survey of pigments in 100 lakes in the Scandes Mountains, northern Sweden, was combined with a reconstruction of Holocene sedimentary pigments from Lake Seukokjaure to assess the major factors regulating phototrophic communities, and how these controls may have changed during t...

  18. Palaeolimnological assessment of environmental change over the last two centuries in oligotrophic Lake Nohipalu Valgjärv, southern Estonia

    Directory of Open Access Journals (Sweden)

    Heinsalu, Atko

    2009-06-01

    Full Text Available The main objectives of this study were to reconstruct the environmental conditions for a small oligotrophic lake during the last two centuries, to determine if the environment of the lake was anthropogenically mediated, and to assess the pre-impact reference conditions with palaeolimnological techniques. A short sediment core from Lake Nohipalu Valgjärv was analysed in detail for diatom assemblages as well as for loss-on-ignition measurements. Accurate chronology of the sediment core was established and evaluated by different independent approaches – 210Pb, 137Cs, and 241Am dating, and the distribution of spheroidal fly-ash particles in sediments. Quantitative inference models based on sedimentary diatoms were applied to reconstruct changes in past lake water pH. Before the mid-19th century, Nohipalu Valgjärv was an oligotrophic lake with clear water continuously transparent down to the bottom and with rich benthic diatom flora. Since the early second half of the 19th century, presumably as a result of forest logging around the lake, water transparency decreased and benthic diatom productivity diminished, and the lake did not recover any more to natural baseline conditions. Due to peat mining activities in the Meenikunno bog, the quality of lake water has changed during the last two decades. The lowered lake level, deteriorated light climate, and decreased pH are the most important environmental variables that have influenced the lake ecosystem.

  19. Ontario demand response scenarios

    International Nuclear Information System (INIS)

    Strategies for demand management in Ontario were examined via 2 scenarios for a commercial/institutional building with a normal summertime peak load of 300 kW between 14:00 and 18:00 during a period of high electricity demand and high electricity prices. The first scenario involved the deployment of a 150 kW on-site generator fuelled by either diesel or natural gas. The second scenario involved curtailing load by 60 kW during the same periods. Costs and benefits of both scenarios were evaluated for 3 groups: consumers, system operators and society. Benefits included electricity cost savings, deferred transmission capacity development, lower system prices for electricity, as well as environmental changes, economic development, and a greater sense of corporate social responsibility. It was noted that while significant benefits were observed for all 3 groups, they were not substantial enough to encourage action, as the savings arising from deferred generation capacity development do not accrue to individual players. The largest potential benefit was identified as lower prices, spread across all users of electricity in Ontario. It was recommended that representative bodies cooperate so that the system-wide benefits can be reaped. It was noted that if 10 municipal utilities were able to have 250 commercial or institutional customers engaged in distributed response, then a total peak demand reduction of 375 MW could be achieved, representing more than 25 per cent of Ontario's target for energy conservation. It was concluded that demand response often involves the investment of capital and new on-site procedures, which may affect reactions to various incentives. 78 refs., 10 tabs., 5 figs

  20. Ontario Hydro CANDU operating experience

    International Nuclear Information System (INIS)

    The CANDU Pressurized Heavy Water (CANDU-PHW) type of nuclear-electric generating station has been developed jointly by Atomic Energy of Canada Limited and Ontario Hydro. This report highlights Ontario Hydro's operating experience using the CANDU-PHW system, with a focus on the operating performance and costs, reliability of system components and nuclear safety considerations for the workers and the public

  1. Ontario Hydro CANDU operating experience

    International Nuclear Information System (INIS)

    The CANDU Pressurized Heavy Water (CANDU-PHW) type of nuclear-electric generating station has been developed jointly by Atomic Energy of Canada Limited and Ontario Hydro. This report highlights Ontario Hydro's operating experience using the CANDU-PHW system, with a focus on worker and public safety, operating performance and costs, and reliability of system components

  2. Lake breezes in the southern Great Lakes region and their influence during BAQS-Met 2007

    Directory of Open Access Journals (Sweden)

    D. M. L. Sills

    2011-02-01

    Full Text Available Mesoscale observations from the BAQS-Met field experiment during the summer of 2007 were integrated and manually analyzed in order to identify and characterize lake breezes in the southern Great Lakes region of North America, and assess their potential impact on air quality. Lake breezes were found to occur on 90% of study days, often occurring in conditions previously thought to impede their development. They affected all parts of the study region, including southwestern Ontario and nearby portions of southeast Michigan and northern Ohio, occasionally penetrating inland from 100 km to over 200 km. Occurrence rates and penetration distances were found to be higher than previously reported in the literature. This more accurate depiction of observed lake breezes allows a better understanding of their influence on the production and transport of pollutants in this region.

    The observational analyses were compared with output from subsequent runs of a high-resolution numerical weather prediction model. The model accurately predicted lake breeze occurrence in a variety of synoptic wind regimes, but selected cases showed substantial differences in the detailed timing and location of lake-breeze fronts, and with the initiation of deep moist convection. Knowledge of such strengths and weaknesses will assist with interpretation of results from air quality modelling driven by this meteorological model.

  3. Assessing lake typologies and indicator fish species for Italian natural lakes using past fish richness and assemblages

    OpenAIRE

    Volta, Pietro; Alessandro OGGIONI; Roberta BETTINETTI; Jeppesen, Erik

    2011-01-01

    In order to establish a fish-based typology of Italian lakes and identify possible reference and indicator fish species for each lake type, we analysed historical data on fish assemblages of all Italian natural lakes[0.5 km2 from the period prior to the major decline in water quality in the 1950s. General linear regression models showed the ecoregion and lake altitude being the best predictors of fish species richness. The number of species was significantly higher in the Alpine than in the M...

  4. Assessment of Water and Sediment Physical-Chemical Composition in the West Coast of Maracaibo Lake

    OpenAIRE

    Jorge Moronta-Riera; Beatriz Riverón-Zaldívar

    2016-01-01

    The objective of this investigation was to determine the physical and chemical composition of the water streams and sediments of the Maracaibo Lake in three sampling areas located in Tía Juana, Lagunillas and Ceuta in order to know the level of contamination and assess water quality based on permissible values established by the 883 Decree. The results indicate that the overall hydrocarbon concentrations in the water and sediments are above permissible levels. It is concluded that petroleum p...

  5. Contamination and risk assessment of heavy metals in bottom sediments from Lake Valencia, Venezuela

    OpenAIRE

    González A; Palma M. G.; Ziegler K.; González E.; Álvarez M. A.

    2013-01-01

    The contamination and risk assessment of heavy metals in the bottom sediments of the Lake Valencia, Venezuela, was performed by determining the Enrichment Factor (EF), the Geoaccumulation Factor (Igeo), the availability of metals and the Risk Index Code (RAC). The sediments were anthropogenic ally enriched with Pb, Zn, Cu and Cr and classified as uncontaminated to moderately contaminated, with a medium risk of Zn, Co, Ni and Cr, and low risk of Cu, Pb and Cd. Analysis of correlations and PCA ...

  6. Environmental Assessment : Chronic wasting disease management during an epidemic occurrence at Crescent Lake National Wildlife Refuge, Garden County, Nebraska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Environmental Assessment is needed to manage for chronic wasting disease on Crescent Lake NWR. There were two alternatives seriously considered: no action and...

  7. Assessing the utility of geospatial technologies to investigate environmental change within lake systems.

    Science.gov (United States)

    Politi, Eirini; Rowan, John S; Cutler, Mark E J

    2016-02-01

    Over 50% of the world's population live within 3 km of rivers and lakes highlighting the on-going importance of freshwater resources to human health and societal well-being. Whilst covering c. 3.5% of the Earth's non-glaciated land mass, trends in the environmental quality of the world's standing waters (natural lakes and reservoirs) are poorly understood, at least in comparison with rivers, and so evaluation of their current condition and sensitivity to change are global priorities. Here it is argued that a geospatial approach harnessing existing global datasets, along with new generation remote sensing products, offers the basis to characterise trajectories of change in lake properties e.g., water quality, physical structure, hydrological regime and ecological behaviour. This approach furthermore provides the evidence base to understand the relative importance of climatic forcing and/or changing catchment processes, e.g. land cover and soil moisture data, which coupled with climate data provide the basis to model regional water balance and runoff estimates over time. Using examples derived primarily from the Danube Basin but also other parts of the World, we demonstrate the power of the approach and its utility to assess the sensitivity of lake systems to environmental change, and hence better manage these key resources in the future.

  8. Assessing the utility of geospatial technologies to investigate environmental change within lake systems.

    Science.gov (United States)

    Politi, Eirini; Rowan, John S; Cutler, Mark E J

    2016-02-01

    Over 50% of the world's population live within 3 km of rivers and lakes highlighting the on-going importance of freshwater resources to human health and societal well-being. Whilst covering c. 3.5% of the Earth's non-glaciated land mass, trends in the environmental quality of the world's standing waters (natural lakes and reservoirs) are poorly understood, at least in comparison with rivers, and so evaluation of their current condition and sensitivity to change are global priorities. Here it is argued that a geospatial approach harnessing existing global datasets, along with new generation remote sensing products, offers the basis to characterise trajectories of change in lake properties e.g., water quality, physical structure, hydrological regime and ecological behaviour. This approach furthermore provides the evidence base to understand the relative importance of climatic forcing and/or changing catchment processes, e.g. land cover and soil moisture data, which coupled with climate data provide the basis to model regional water balance and runoff estimates over time. Using examples derived primarily from the Danube Basin but also other parts of the World, we demonstrate the power of the approach and its utility to assess the sensitivity of lake systems to environmental change, and hence better manage these key resources in the future. PMID:26521989

  9. Assessing Future Ecosystem Services: a Case Study of the Northern Highlands Lake District, Wisconsin

    Directory of Open Access Journals (Sweden)

    C. Lisa Dent

    2003-12-01

    Full Text Available The Northern Highlands Lake District of Wisconsin is in transition from a sparsely settled region to a more densely populated one. Expected changes offer benefits to northern Wisconsin residents but also threaten to degrade the ecological services they rely on. Because the future of this region is uncertain, it is difficult to make decisions that will avoid potential risks and take advantage of potential opportunities. We adopt a scenario planning approach to cope with this problem of prediction. We use an ecological assessment framework developed by the Millennium Ecosystem Assessment to determine key social and ecological driving forces in the Northern Highlands Lake District. From these, we describe three alternative scenarios to the year 2025 in which the projected use of ecological services is substantially different. The work reported in this paper demonstrates how scenarios can be developed for a region and provides a starting point for a participatory discussion of alternative futures for northern Wisconsin. Although the future is unknowable, we hope that the assessment process begun in this paper will help the people of the Northern Highlands Lake District choose the future path of their region.

  10. Electricity market readiness plan : Ontario Energy Board

    International Nuclear Information System (INIS)

    This document informs electric power market participants of the Ontario Energy Board's newly developed market readiness plan and target timelines that local distribution companies (LDCs) must meet for retail marketing. The Ontario Energy Board's plan incorporates relevant independent market operator (IMO)-administered market milestones with retail market readiness targeted for September 2001. The market readiness framework involves a self-certification process for LDCs by August 10, 2001, through which the Board will be able to monitor progress and assess the feasibility of meeting the target timelines. For retail market readiness, all LDCs will have to calculate settlement costs, produce unbundled bills, provide standard supply service, change suppliers and accommodate retail transactions. LDCs must be either authorized participants in the IMO-administered market or become retail customers of their host LDC. Unbundled bills will include itemized charges for energy price, transmission, distribution and debt retirement charge. 1 tab., 1 fig

  11. Assessment of oxidative stress and histopathology in juvenile northern pike (Esox lucius) inhabiting lakes downstream of a uranium mill

    International Nuclear Information System (INIS)

    Lakes receiving effluent from the Key Lake uranium mill in northern Saskatchewan contain elevated trace metals, some of which are associated with increased reactive oxygen species (ROS) in cells and tissues causing oxidative stress. The potential for oxidative stress was assessed in juvenile (age 1+) northern pike (Esox lucius) collected from two exposure (high and low) and one reference lake near the Key Lake operation. The concentrations of total, reduced and oxidized glutathione and the ratio of oxidized to reduced glutathione in liver and kidney did not differ significantly among pike collected from exposure and reference lakes, with the exception of low exposure pike kidney that had significantly greater oxidized glutathione and ratio of oxidized to reduced glutathione. The concentrations of by-products of lipid peroxidation (malondialdehyde and 4-hydroxyalkenal) were significantly greater in kidney of pike collected from the reference lake compared to both exposure lakes. The activity of the antioxidant enzyme glutathione peroxidase in liver was greater in pike collected from the high exposure lake compared to the reference lake. Histopathological evaluations revealed greater pathology in reference lake pike as indicated by a greater number of pyknotic and fragmented nuclei and dilated tubules as well as a thickening of Bowman's capsule in kidney, and as a thickening of the primary filament epithelial padding in gills. In liver, hepatocyte morphology, including transsectional area and degree of vacuolation, differed among lakes without any clear signs of pathology. Trace metal analyses of muscle showed that eight elements (arsenic, cobalt, copper, iron, molybdenum, selenium, thallium, and uranium) were significantly elevated in pike collected from both exposure lakes compared to reference. These results provide only limited evidence of oxidative stress in exposure pike tissues and no evidence of histopathology despite indications that trace metals, most

  12. Assessment of oxidative stress and histopathology in juvenile northern pike (Esox lucius) inhabiting lakes downstream of a uranium mill

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Jocelyn M. [Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3 (Canada); Janz, David M., E-mail: david.janz@usask.ca [Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3 (Canada); Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, SK, S7N 5B4 (Canada)

    2009-05-17

    Lakes receiving effluent from the Key Lake uranium mill in northern Saskatchewan contain elevated trace metals, some of which are associated with increased reactive oxygen species (ROS) in cells and tissues causing oxidative stress. The potential for oxidative stress was assessed in juvenile (age 1+) northern pike (Esox lucius) collected from two exposure (high and low) and one reference lake near the Key Lake operation. The concentrations of total, reduced and oxidized glutathione and the ratio of oxidized to reduced glutathione in liver and kidney did not differ significantly among pike collected from exposure and reference lakes, with the exception of low exposure pike kidney that had significantly greater oxidized glutathione and ratio of oxidized to reduced glutathione. The concentrations of by-products of lipid peroxidation (malondialdehyde and 4-hydroxyalkenal) were significantly greater in kidney of pike collected from the reference lake compared to both exposure lakes. The activity of the antioxidant enzyme glutathione peroxidase in liver was greater in pike collected from the high exposure lake compared to the reference lake. Histopathological evaluations revealed greater pathology in reference lake pike as indicated by a greater number of pyknotic and fragmented nuclei and dilated tubules as well as a thickening of Bowman's capsule in kidney, and as a thickening of the primary filament epithelial padding in gills. In liver, hepatocyte morphology, including transsectional area and degree of vacuolation, differed among lakes without any clear signs of pathology. Trace metal analyses of muscle showed that eight elements (arsenic, cobalt, copper, iron, molybdenum, selenium, thallium, and uranium) were significantly elevated in pike collected from both exposure lakes compared to reference. These results provide only limited evidence of oxidative stress in exposure pike tissues and no evidence of histopathology despite indications that trace metals, most

  13. Assessment of oxidative stress and histopathology in juvenile northern pike (Esox lucius) inhabiting lakes downstream of a uranium mill.

    Science.gov (United States)

    Kelly, Jocelyn M; Janz, David M

    2009-05-17

    Lakes receiving effluent from the Key Lake uranium mill in northern Saskatchewan contain elevated trace metals, some of which are associated with increased reactive oxygen species (ROS) in cells and tissues causing oxidative stress. The potential for oxidative stress was assessed in juvenile (age 1+) northern pike (Esox lucius) collected from two exposure (high and low) and one reference lake near the Key Lake operation. The concentrations of total, reduced and oxidized glutathione and the ratio of oxidized to reduced glutathione in liver and kidney did not differ significantly among pike collected from exposure and reference lakes, with the exception of low exposure pike kidney that had significantly greater oxidized glutathione and ratio of oxidized to reduced glutathione. The concentrations of by-products of lipid peroxidation (malondialdehyde and 4-hydroxyalkenal) were significantly greater in kidney of pike collected from the reference lake compared to both exposure lakes. The activity of the antioxidant enzyme glutathione peroxidase in liver was greater in pike collected from the high exposure lake compared to the reference lake. Histopathological evaluations revealed greater pathology in reference lake pike as indicated by a greater number of pyknotic and fragmented nuclei and dilated tubules as well as a thickening of Bowman's capsule in kidney, and as a thickening of the primary filament epithelial padding in gills. In liver, hepatocyte morphology, including transsectional area and degree of vacuolation, differed among lakes without any clear signs of pathology. Trace metal analyses of muscle showed that eight elements (arsenic, cobalt, copper, iron, molybdenum, selenium, thallium, and uranium) were significantly elevated in pike collected from both exposure lakes compared to reference. These results provide only limited evidence of oxidative stress in exposure pike tissues and no evidence of histopathology despite indications that trace metals, most

  14. Assessment of climate and land use changes impacts on the rivers inflow to the Lake Baikal

    Science.gov (United States)

    Kurovskaia, Victoriia; Semenova, Olga; Vinogradova, Tatyana

    2016-04-01

    Baikal is the deepest lake in the world and one of the biggest reservoirs of fresh water. The aim of this research was to analyze the long-term variability of characteristics of river inflow to the Lake using the historical data and project possible changes in the face of non-stationary climate and land use based on hydrological modelling. The basin of the Lake Baikal has area about 545 000 km2, half of which is situated in Russia. It is characterized by different climate and landscape conditions with annual flow depth varying from 30 to more than 600 mm. Nowadays active development and use of natural resources as well as climate changes have a strong impact on the regime of rivers inflow to the Lake. The watersheds response caused by environmental non-stationarity can be variable and unpredictable. Therefore adequate hydrological models with robust parametrization are required for future projections. This study consisted of two parts. Initially we compiled the database of daily runoff data for about 50 gauges in the basin of the Baikal Lake with continuous period of observations 30-50 years. The data was used to assess the characteristics of river inflow to the Lake for the historical period and estimate observed changes due to current climate change. For the development of future projections we have chosen several small and middle-size representative watersheds in different parts of the Lake basin with area from 151 to 7800 km2 and various types of hydrological regime. The data base for modelling was developed which included the information about landscapes, soils, dominating hydrological processes. The hydrological model parameters for different dominant landscapes were estimated based on that information. We applied distributed process-based hydrological model Hydrograph developed in State Hydrological Institute, Russia (Vinogradov et al., 2011; Semenova et al., 2013). It describes all essential processes of land hydrological cycle including detailed algorithm

  15. Constraining the exercise of market power in Ontario electricity markets

    International Nuclear Information System (INIS)

    After releasing its White Paper in November 1997, the Ontario government enacted the Energy Competition Act 1998, which consisted of five schedules designed to implement White Paper policies, including the Electricity Act 1998, and the Ontario Energy Board Act 1998. Both Acts promote competition in Ontario's energy sector. Each Act also contains references to market power. This paper discusses the relevance and meaning of the term 'market power' in Ontario's deregulated electricity markets and reviews areas of overlap between Ontario's new regulatory regime and the Competition Act. The nature of market power, the means of assessing, and the structural remedies for eliminating or constraining it are discussed at length. As far as the market power of Ontario's Genco is concerned the Market Design Committee has recommended a mixture of short-term behaviour remedies and long-term structural solutions to deal with the issue. Some of these measures are: (1) subjecting Genco to a price cap and consumer rebate regime for at least four years of the competitive market, (2) obliging Genco to reduce its 'tier-two' generation capacity to no more than 35 per cent within 42 months of the market opening, (3) inter-tie capacity with neighbouring jurisdictions, thereby intensifying competitions from out-of-province generators, and (4) prohibiting Genco from acquiring more than 35 per cent of firm long-term in-bound transmission capacity rights. 43 refs

  16. Waterborne parasites and physico-chemical assessment of selected lakes in Malaysia.

    Science.gov (United States)

    Onichandran, Subashini; Kumar, Thulasi; Lim, Yvonne A L; Sawangjaroen, Nongyao; Andiappan, Hemah; Salibay, Cristina C; Chye, Tan Tian; Ithoi, Init; Dungca, Julieta Z; Sulaiman, Wan Y W; Ling, Lau Yee; Nissapatorn, Veeranoot

    2013-12-01

    The objective of this study was to assess the physico-chemical parameters and waterborne parasites in selected recreational lakes from Malaysia. Samples were collected from seven stations of Recreational Lake A (RL-A) and six stations of Recreational Lake B (RL-B). The samples were processed to detect the presence of Giardia spp. and Cryptosporidium spp. using immunomagnetic separation kit, helminth eggs or ova by bright field microscopy and Acanthamoeba spp. by cultivation in non-nutrient agar. Chemical parameters such as ammonia, chlorine, fluoride, nitrate and nitrite and physical parameters such as dissolved oxygen, electrical conductivity, pH, salinity, temperature and total dissolved solid were also measured. Both lakes were freshwater with salinity ranging from 0.05 to 0.09 ppt. Most stations of these lakes were contaminated with Cryptosporidium spp., Giardia spp., Ascaris spp. and hookworm. Schistosoma spp. was found in RL-B only, while Acanthamoeba spp. was found in all stations. Of all sampling sites, station 5 of RL-B is the most contaminated. Linear regression and correlation analysis revealed that Giardia spp. and Schistosoma spp. showed a significant negative correlation with turbidity (p < 0.01). Based on the preliminary data obtained, it is clearly shown that there is a necessity to implement the detection of waterborne parasites and physico-chemical analysis in Malaysia. Future work on heavy metals (chromium, copper, mercury and zinc) is recommended to enhance the overall water quality monitoring and to take appropriate safety measures to ensure maintenance of good water standards. PMID:24046263

  17. ONTARIO GRAPE PRODUCTION ECONOMIC IMPACT

    OpenAIRE

    Grier, Kevin; Martin, Larry J.; Stiefelmeyer, Kate

    2000-01-01

    This report was undertaken in order to measure the economic impacts of the grape industry on the Ontario economy and the impacts of maintaining the Wine Content Act at the 30% level. It will also provide an estimate of the benefits to grape growers and Ontario of increasing the requirements of the Wine Content Act to 75%. Specifically, the objectives are: 1. To determine the current contribution of the processing grape industry to the economy of Ontario. 2. To estimate the economic effects of...

  18. Using scenarios to assess possible future impacts of invasive species in the Laurentian Great Lakes

    Science.gov (United States)

    Lauber, T. Bruce; Stedman, Richard C.; Connelly, Nancy A; Rudstam, Lars G.; Ready, Richard C; Poe, Gregory L; Bunnell, David; Hook, Tomas O.; Koops, Marten A.; Ludsin, Stuart A.; Rutherford, Edward S; Wittmann, Marion E.

    2016-01-01

    The expected impacts of invasive species are key considerations in selecting policy responses to potential invasions. But predicting the impacts of invasive species is daunting, particularly in large systems threatened by multiple invasive species, such as North America’s Laurentian Great Lakes. We developed and evaluated a scenario-building process that relied on an expert panel to assess possible future impacts of aquatic invasive species on recreational fishing in the Great Lakes. To maximize its usefulness to policy makers, this process was designed to be implemented relatively rapidly and consider a range of species. The expert panel developed plausible, internally-consistent invasion scenarios for 5 aquatic invasive species, along with subjective probabilities of those scenarios. We describe these scenarios and evaluate this approach for assessing future invasive species impacts. The panel held diverse opinions about the likelihood of the scenarios, and only one scenario with impacts on sportfish species was considered likely by most of the experts. These outcomes are consistent with the literature on scenario building, which advocates for developing a range of plausible scenarios in decision making because the uncertainty of future conditions makes the likelihood of any particular scenario low. We believe that this scenario-building approach could contribute to policy decisions about whether and how to address the possible impacts of invasive species. In this case, scenarios could allow policy makers to narrow the range of possible impacts on Great Lakes fisheries they consider and help set a research agenda for further refining invasive species predictions.

  19. Climate change vulnerabilities- an integrated assessment in Pyramid Lake Paiute Indian Reservation

    Science.gov (United States)

    Gautam, M. R.; Chief, K.; Wilde, K.; Smith, W.

    2011-12-01

    There are increasing concerns of potential climate change impacts that may place the Truckee River Basin in Nevada under unprecedented stress. We hypothesized that Pyramid Lake, a terminal lake of Truckee River, is prone to climatic as well as non-climatic stressors stemming from cumulative impacts from upstream urban areas and activities. Thus climate change may impair the ability of a major downstream water user, the Pyramid Lake Paiute Tribe (PLPT), to cope and adapt. The conventional approach in assessing vulnerability primarily focuses on hazards or biophysical vulnerabilities, such as water availability, floods, and drought impact. However, we found it inadequate to address the overall vulnerability of the PLPT. Thus in addition to biophysical vulnerabilities, intrinsic and external vulnerabilities were considered such as socio-economic variables (e.g. adaptive capacity) and policy and legal drivers (e.g. water rights). We proposed an elaborate framework for an integrated vulnerability assessment by adapting IPCC framework for vulnerability assessment, the Exposure-Sensitivity-Adaptive Capacity, and applied it to PLPT. Analysis of projected climate change dataset pointed towards increased incidences of floods and droughts and a warming trend over the whole basin with a higher rate at the lower basin in the future. In effort to understand how climatic trends trigger the vulnerability of PLPT, a multi-pronged approach was employed to understand key tribal livelihood assets including an in-depth analysis of the adaptive capacity of PLPT, a climate change survey, and a historical analysis of water conflict and negotiation. Results of the survey identified key natural assets as the lake, endangered fish, rangeland, and wetlands. The framework of a casual-loop diagram was developed in a system dynamic model that incorporated opinions of tribal stakeholders and other experts to evaluate how potential future climate changes might impact the endangered Cui ui fish

  20. Ontario electricity deregulation : evolution or revolution

    International Nuclear Information System (INIS)

    The deregulation of Ontario's electric power industry leaves consumers with a whole new experience of risks and rewards when it comes to buying power. The original date for the opening of both the wholesale and retail power markets in Ontario was scheduled for November 2000, but this date will be delayed by at least 6 months due to lack of necessary infrastructure. The new opening date will depend on government's assessment of market conditions. The investment community is urging the government to control the debt load of the previous provincial utility. In general, deregulation is receiving criticism based on the experience of problems in California and Alberta. However, the agency responsible for Ontario's electricity markets claims that the province will not be hit with power blackouts like California because Ontario has enough power generation to meet demand, unlike California which relies heavily on imports. In a deregulated market, all generators of electricity will bid on their supply and the independent market operator (IMO) will rank the bids by price and stack the bids for dispatch. The demand curve will be created by consumer usage. At low demand periods (such as early morning and off season months), the demand curve will be low and only generation required to meet the demand will be turned on. Spot market prices will be a reality in a deregulated energy market. The consumer will see an increase in electricity prices. However, the return of Pickering 'A' nuclear power plant will mean more low cost energy which will suppress prices and provide sufficient reserve margins to meet energy demands. tabs., figs

  1. Assessing variability of water quality in a groundwater-fed perennial lake of Kashmir Himalayas using linear geostatistics

    Science.gov (United States)

    Sarah, S.; Jeelani, Gh.; Ahmed, Shakeel

    2011-06-01

    This paper presents a study on Manasbal lake, which is one of the high altitude lakes in the Kashmir Valley, India. Eighteen water samples were analysed for major ions and trace elements to assess the variability of water quality of the lake for various purposes. Geostatistics, the theory of regionalized variables, was then used to enhance the dataset and estimate some missing spatial values. Results indicated that the concentration of major ions in the water samples in winter was higher than in summer. The scatter diagrams suggested the dominance of alkaline earths over the alkali elements. Three types of water were identified in the lake that are referred to as Ca-HCO3, Mg-HCO3 and hybrid types. The lake water was found to be controlled by rock-water interaction with carbonate lithology as a dominant source of the solutes. The major (Ca2 + , Mg2 + , Na + , K + , NO3 and {{HCO}}3-, CO3 and Cl) and trace elements of the lake water were within the World Health Organization standards, therefore the lake water was considered chemically safe for drinking purposes. Although NO3 concentration (ranging from 1.72 to 2 mg/L), is within the permissible limit and not very alarming, the gradually increasing trend is not acceptable. It is however, important to guard its spatio-temporal variability as the water is used for domestic as well as agricultural purposes. This study is significant as hydrogeological information on such high altitude lakes in India is scanty.

  2. Shale gas opportunities in Ontario

    Energy Technology Data Exchange (ETDEWEB)

    Carter, T. [Ontario Ministry of Natural Resources, London, ON (Canada). Petroleum Resources Centre

    2008-07-01

    Shale gas resources in southern Ontario were reviewed. Canadian oil and gas developers are now considering the exploitation of unconventional shale gas resources in southern Ontario. Petroleum well records maintained by the Ontario Ministry of Natural Resources and surveys conducted by the Geological Survey of Canada have recorded gas deposits in the Upper Devonian Kettle Point formation; the Middle Devonian Marcellus formation; the Upper Ordovician Blue Mountain formation; and the Collingwood member of the Lindsay formation. Water well records have identified shale gas deposits where the formations sub-crop beneath glacial drifts. Shallow gas wells drilled in the mid-twentieth century in central southern Ontario have recovered significant gas flows from the Georgian Bay and Queenston formations. However, there are currently no commercial shale gas projects in any of the identified regions. 30 refs., 10 figs.

  3. Ontario Teachers' Deprofessionalization and Proletarianization.

    Science.gov (United States)

    Filson, Glen

    1988-01-01

    Discusses teachers' class location in capitalist societies in terms of major sociological perspectives. Identifies corporate capitalist class categories that distinguish professionals from proletarians, and applies these categories to Ontario teachers at different occupational levels. (44 references) (SV)

  4. ASSESSMENT OF IMPACT OF WARM WATER DISCHANGE OF GUSINOOZERSKAYA GRES ON THE ICE REGIME OF GUSINOE LAKE (IN THE WESTERN TRANSBAIKALIA

    Directory of Open Access Journals (Sweden)

    Chebunina N. S.

    2016-02-01

    Full Text Available The article is devoted to the assessment adverse effects of Gusinoozerskaya GRES on the ecosystem of Lake Gusinoe. It shows the dynamics of the ice regime of Lakes Gusinoe near Gusinoozerskaya GRES. Is noted that industrial pollution reduces the quality of the water in the lake

  5. Developing Multi-Lake Regulation Plans for the Great Lakes through Multi-Scenario Optimization

    Science.gov (United States)

    Razavi, S.; Tolson, B.; Asadzadeh, M.

    2011-12-01

    Water levels in the Great Lakes- St. Lawrence freshwater system (Lakes Superior, Michigan, Huron, Erie, and Ontario as well as the St. Lawrence River) impact a variety of stakeholder groups such as hydropower producers, the shipping industry, shoreline property owners and recreational boaters. Although the system is currently managed by control structures at two locations (Lake Superior and Lake Ontario outflows are controlled), there is concern that future extreme climates will generate water supply sequences to the system that will substantially increase the frequency and persistence of extreme water levels imposing millions of dollars of losses to Canadian and American economies. This work partially summarizes a study under The International Upper Great Lakes Study (International Joint Commission) to provide an exploratory conceptual analysis of how and to what extent new control structures in the system could be used to minimize the risks posed by extreme water levels outside of the historic range. In this study, two new hypothetical control structures were investigated to regulate Lake Michigan-Huron and Lake Erie outflows. Multiple regulation plans were developed to operate the hypothetical structures in the St. Clair and/or Niagara rivers in combination with the two existing control structures in the St. Marys and St. Lawrence Rivers. The regulation plans were defined by multi-lake rule curves whose parameters were determined through a simulation-optimization procedure. As there is a high level of uncertainty in future climate, multiple water supply sequences, each 70 years long, representing different future climate scenarios were considered. A multi-scenario based optimization formulation was developed aiming to keep the water levels within the historical range and to minimize and evenly distribute extreme water levels across the system. The dynamically dimensioned search (DDS) algorithm was applied to optimize the multi-scenario based formulation. As the

  6. Hydroacoustic Assessment of Abundance and Diel Distribution of Sockeye Salmon and Kokanee in the Sawtooth Valley Lakes, Idaho

    OpenAIRE

    Beauchamp, D; Luecke, Chris; Wurtsbaugh, Wayne A.; Gross, H.G.; Budy, P.; Spaulding, S.; Dilenger, R.; Gubala, C. P.

    1997-01-01

    We used dual-beam hydroacoustics and echo integration techniques, combined with midwater trawling and gillnetting, to assess the abundance and distribution of the endangered Snake River juvenile sockeye salmon and resident kokanee (both Oncorhynchus nerka) in Sawtooth Valley lakes of Idaho during September 1991 and 1992. Abundance of O. nerka varied among the four lakes containing this species (12,500–257,000) and varied between years in Redfish Lake (86,400 in 1994 and 241,000 in 1992) and ...

  7. Ontario perspective on interregional markets

    International Nuclear Information System (INIS)

    On May 1, 2002, wholesale and retail electricity markets in Ontario were opened to competition. The industry structure has been completely unbundled into separate entities for power generation, distribution and transmission. There are currently 20 generators, 90 distributors and 4 transmitters in Ontario. Trade with neighbouring jurisdictions has increased and now accounts for 10 to 15 per cent of demand on summer peak days. Import/export capability with the United States (northeast and midwest) and other Canadian provinces (Quebec and Manitoba) is 4,000 to 6,000 MW. Ontario has not had new generation or transmission capacity in several years and the heat waves of summer 2002 resulted in a heavier power demand than forecasted. The province had to rely heavily on power imports resulting in high and volatile electricity prices. In response to customer complaints, the Ontario government froze retail rates and in a recent policy directive announced a public ownership policy for transmission with further consultation on improving supply competition in Ontario. FERC order 888 and the increased role of independent power producers has improved trading opportunities between Canada and the United States. The presentation highlighted recent trade trends and outlined the specific impact of the Standard Market Design on Canadian markets. It was noted that Ontario should work on ensuring power reliability, transmission planning, inter-regional coordination, and joint investments with neighbouring jurisdictions. 9 figs

  8. Genetic effects of habitat restoration in the Laurentian Great Lakes: an assessment of lake sturgeon origin and genetic diversity

    Science.gov (United States)

    Jamie Marie Marranca; Amy Welsh; Roseman, Edward F.

    2015-01-01

    Lake sturgeon (Acipenser fulvescens) have experienced significant habitat loss, resulting in reduced population sizes. Three artificial reefs were built in the Huron-Erie corridor in the Great Lakes to replace lost spawning habitat. Genetic data were collected to determine the source and numbers of adult lake sturgeon spawning on the reefs and to determine if the founder effect resulted in reduced genetic diversity. DNA was extracted from larval tail clips and 12 microsatellite loci were amplified. Larval genotypes were then compared to 22 previously studied spawning lake sturgeon populations in the Great Lakes to determine the source of the parental population. The effective number of breeders (Nb) was calculated for each reef cohort. The larval genotypes were then compared to the source population to determine if there were any losses in genetic diversity that are indicative of the founder effect. The St. Clair and Detroit River adult populations were found to be the source parental population for the larvae collected on all three artificial reefs. There were large numbers of contributing adults relative to the number of sampled larvae. There was no significant difference between levels of genetic diversity in the source population and larval samples from the artificial reefs; however, there is some evidence for a genetic bottleneck in the reef populations likely due to the founder effect. Habitat restoration in the Huron-Erie corridor is likely resulting in increased habitat for the large lake sturgeon population in the system and in maintenance of the population's genetic diversity.

  9. Effect of acidic lake water on survival of aurora trout (Salvelinus fontinalis) embryos and alevins

    Energy Technology Data Exchange (ETDEWEB)

    Snucins, E.J.; Liimatainen, V.A.; Gale, P.A.

    1988-01-01

    During the 1960s the aurora trout, a rare color variant of the brook trout, disappeared from its native waters in northeastern Ontario. Its disappearance was attributed to acidification of the waters by atmospheric deposition of industrial emissions from metal smelters at Sudbury, Ontario. Recently, water quality in the Sudbury area has improved due to emission reductions. These experiments were designed to assess the toxicity of current water quality in the native lakes of aurora trout. During May 1984, hatchery-reared aurora trout alevins were held for 4 days in 3 of their native lakes (Whiligig, Whitepine and Wilderness with pH 4.5-4.8) and a control lake, Regan Lake (pH 6.5), and survival rates were assessed. In a second bioassay, embryos and alevins were buried in the substrate at 3 groundwater upwelling sites, and survival rates were assessed. The final test involved a 14-day exposure of groundwater-reared fish to ambient conditions.

  10. Assessment of priority phenolic compounds in sediments from an extremely polluted coastal wetland (Lake Maryut, Egypt).

    Science.gov (United States)

    Khairy, Mohammed A

    2013-01-01

    Although high concentrations of trace organic pollutants were recorded along the Egyptian Mediterranean Coast and its corresponding coastal wetlands, no published data are available for the levels of phenolic compounds. Thus, this work aimed to investigate the levels of phenolic compounds in sediments of a heavily polluted coastal wetland (Lake Maryut, Egypt). For that purpose, a method was optimized for the extraction and detection of chlorophenols, methylphenols, and nitrophenols in sediments using GC-MS. Sediments were extracted with 0.1 M NaOH/methanol by sonication. Cleanup of sediment extracts using liquid-liquid extraction and SPE was found important to remove most of the interfering co-extracts. The proposed analytical methodology was validated by analysis of matrix spikes. Detection limits were 0.063-0.694 μg/kg dw for sediments. Good recoveries (70-110%) and precision values (RSD parts per billion level in sediments. The method was applied to investigate the level of contamination with phenols in 19 sediment samples from Lake Maryut. Results revealed that higher concentrations were observed in the main basin (MB) of Lake Maryut affected by the discharge of effluents from a primary wastewater treatment plant, direct discharge of industrial effluents, domestic wastes, and agricultural effluents from Qalaa Drain (QD). Chlorophenols (CPs) were the major group detected in the lake sediments followed by methylphenols (MPs) and nitrophenols (NPs). CPs were dominated by 2-, 4-, and 3-chlorophenols. Concentrations of CPs were higher at the north and northwestern parts of the MB indicating the influence of industrial effluents discharged into the lake. On the other hand, higher concentrations of NPs were observed at the south and southwestern parts of the MB, which is subjected to the discharge of agricultural and domestic effluents via QD. Results of the risk assessment revealed that phenol, cresols, 2,4-dinitrophenol, 4-NP, 2-CP, 2,3,4,6-tetrachlorophenol and 2

  11. Modelling the Loktak Lake Basin to Assess Human Impact on Water Resources

    Science.gov (United States)

    Eliza, K.

    2015-12-01

    Loktak Lake is an internationally important, Ramsar designated, fresh water wetland system in the state of Manipur, India. The lake was also listed under Montreux Record on account of the ecological modifications that the lake system has witnessed over time. A characteristic feature of this lake is the extensive occurrence of coalesced, naturally or otherwise, vegetative masses floating over it. A contiguous 40 km2 area of Phumdis, as these vegetative masses are locally referred to, also constitutes the only natural home of the endemic and endangered species of Manipur's brow-antlered deer popularly known as Sangai. Appropriately notified as Keibul Lamjao National Park by Government of India, this natural feature is known to be the world's largest floating park. Water quality and sediment deposition on account of soil erosion in its catchments are some of the emerging concerns along with a reported enhanced frequency and duration of flooding of the shore areas, reduced fish catch within a visibly deteriorated overall natural ecosystem. Disturbances of watershed processes, command area management practices, ineffective as indeed largely absent, waste management practices and management interventions linked to the Loktak Hydroelectric Project are often cited as the principal triggers that are seen to be responsible for the damage. An effective management protocol for the Lake requires a rigorous understanding of its hydrobiology and eco-hydrodynamics. The present study is carried out to establish such a characterization of the various rivers systems draining directly into the Lake using MIKE SHE, MIKE 11 HD and MIKE 11 ECO Lab modelling platforms. Water quality modelling was limited to dissolved oxygen (DO), biological oxygen demand (BOD) and water temperature. Model calibration was done using the available measured water quality data. The derived results were then investigated for causal correlation with anthropogenic influences to assess human impact on water

  12. Bathymetry and absorbitivity of Titan's Ontario Lacus

    Science.gov (United States)

    Hayes, A.G.; Wolf, A.S.; Aharonson, O.; Zebker, H.; Lorenz, R.; Kirk, R.L.; Paillou, P.; Lunine, J.; Wye, L.; Callahan, P.; Wall, S.; Elachi, C.

    2010-01-01

    Ontario Lacus is the largest and best characterized lake in Titan's south polar region. In June and July 2009, the Cassini RADAR acquired its first Synthetic Aperture Radar (SAR) images of the area. Together with closest approach altimetry acquired in December 2008, these observations provide a unique opportunity to study the lake's nearshore bathymetry and complex refractive properties. Average radar backscatter is observed to decrease exponentially with distance from the local shoreline. This behavior is consistent with attenuation through a deepening layer of liquid and, if local topography is known, can be used to derive absorptive dielectric properties. Accordingly, we estimate nearshore topography from a radar altimetry profile that intersects the shoreline on the East and West sides of the lake. We then analyze SAR backscatter in these regions to determine the imaginary component of the liquid's complex index of refraction (Kappa). The derived value, Kappa = (6.1-1.3+1.7) x 10-4, corresponds to a loss tangent of tan Delta = (9.2-2.0+2.5) x 10-4 and is consistent with a composition dominated by liquid hydrocarbons. This value can be used to test compositional models once the microwave optical properties of candidate materials have been measured. In areas that do not intersect altimetry profiles, relative slopes can be calculated assuming the index of refraction is constant throughout the liquid. Accordingly, we construct a coarse bathymetry map for the nearshore region by measuring bathymetric slopes for eleven additional areas around the lake. These slopes vary by a factor of ~5 and correlate well with observed shoreline morphologies.

  13. A needs assessment for climate change education in the Great Lakes region

    Science.gov (United States)

    Rutherford, S.; Schneider, L. B.; Walters, H.

    2011-12-01

    The National Science Foundation funded Great Lakes Climate Change Science and Education Systemic Network project is implementing a two year planning effort to create innovative education programs to benefit the public, formal and informal educators, scientists, and journalists in the region. The current partners include Eastern Michigan University, NOAA's Great Lakes Environmental Research Lab, University of Michigan, Michigan State University, Knight Center for Environmental Journalism, Ashland University, Ann Arbor Hands-On Museum, and the College of Exploration. To create a network we are planning to bring together different stakeholders to write two white papers, one from the scientists' perspective and the other from the educators'(both formal and informal) perspective. The current partners' key personnel have produced a list of possible people/institutions to include in a stakeholder survey. Some of the key personnel developed their databases from scratch. Some used listserves, and others tried a snowball email. To identify the best strategy that will inform these various stakeholders and the public regarding the science of climate change in the Great Lakes Region, a survey was developed for each of the different stakeholders. The survey is divided into three parts: 1) questions which convey some understanding of climate science and climate change 2) demographic questions, and finally 3) questions that pertain to the professional concerns or perspectives of the various stakeholders. This survey is being used to provide the project team with a "needs assessment" from the interested members of those stakeholders. The results from this process will be summarized.

  14. Quantifying, assessing and removing the extreme gas load from meromictic Guadiana pit lake, Southwest Spain.

    Science.gov (United States)

    Boehrer, Bertram; Yusta, Iñaki; Magin, Katrin; Sanchez-España, Javier

    2016-09-01

    High gas charges in deep waters of lakes can represent a hazard to the lives of human beings and animals in the surrounding. As this danger was feared, we quantified the amount of dissolved gas in Guadiana pit lake (Las Herrerías, Huelva; southwest Spain) and documented the temporal evolution over a period of two years. Gas pressure due to dissolved gases, such as carbon dioxide, methane and nitrogen was measured. Based on these data, we assessed the risk and the associated danger of limnic eruptions from the lake and concluded that the present situation cannot be considered safe. By deploying a vertical pipe, the updraft of degassing water was tested and demonstrated: the pilot plant provided enough energy to drive a self-sustained flow. Such a system could be implemented to remove the extreme gas pressure from the deep water. Measurements of discharges could be extrapolated to indicate the size for an efficient plant for the gas removal. The construction of such a system would be technically and economically viable. A reintroduction of degassed water into the monimolimnion would be advisable. PMID:27151503

  15. Methods to assess natural and anthropogenic thaw lake drainage on the western Arctic coastal plain of northern Alaska

    Science.gov (United States)

    Hinkel, Kenneth M.; Jones, Benjamin M.; Eisner, Wendy R.; Cuomo, Chris J.; Beck, Richard A.; Frohn, Robert

    2007-06-01

    Thousands of lakes are found on the Arctic Coastal Plain of northern Alaska and northwestern Canada. Developed atop continuous permafrost, these thaw lakes and associated drained thaw lake basins are the dominant landscape elements and together cover 46% of the 34,570 km2 western Arctic Coastal Plain (WACP). Lakes drain by a variety of episodic processes, including coastal erosion, stream meandering, and headward erosion, bank overtopping, and lake coalescence. Comparison of Landsat multispectral scanner (MSS) imagery from the mid-1970s to Landsat 7 enhanced thematic mapper (ETM+) imagery from around 2000 shows that 50 lakes completely or partially drained over the approximately 25 year period, indicating landscape stability. The lake-specific drainage mechanism can be inferred in some cases and is partially dependant on geographic settings conducive to active erosion such as riparian and coastal zones. In many cases, however, the cause of drainage is unknown. The availability of high-resolution aerial photographs for the Barrow Peninsula extends the record back to circa 1950; mapping spatial time series illustrates the dynamic nature of lake expansion, coalescence, and drainage. Analysis of these historical images suggests that humans have intentionally or inadvertently triggered lake drainage near the village of Barrow. Efforts to understand landscape processes and identify events have been enhanced by interviewing Iñupiaq elders and others practicing traditional subsistence lifestyles. They can often identify the year and process by which individual lakes drained, thereby providing greater dating precision and accuracy in assessing the causal mechanism. Indigenous knowledge has provided insights into events, landforms, and processes not previously identified or considered.

  16. Benthic algal assessment of ecological status in European lakes and rivers: Challenges and opportunities.

    Science.gov (United States)

    Poikane, Sandra; Kelly, Martyn; Cantonati, Marco

    2016-10-15

    This opinion paper introduces a special series of articles dedicated to freshwater benthic algae and their use in assessment and monitoring. This special series was inspired by talks presented at the 9th International Congress on the Use of Algae for Monitoring Rivers and Comparable Habitats (Trento, Italy, 2015), the latest of a series of meetings started in 1991. In this paper, we will first provide a brief overview of phytobenthos methods in Europe. Then, we will turn towards the 'dark side' of phytobenthos and describe four particular problems for phytobenthos assessment in the European Union: (1) over-reliance on a single group of algae (mostly diatoms) to the exclusion of other groups; (2) relatively low adoption of benthic algae for ecological assessments in lakes; (3) absence of measures of phytobenthos abundance; (4) approaches used to define boundaries between ecological classes. Following this, we evaluate the strengths and limitations of current phytobenthos assessment methods against 12 criteria for method evaluation addressing four areas: ecological rationale, performance, feasibility of implementation, and use in communication and management. Using these criteria, we identify and discuss three general challenges for those developing new methods for phytobenthos-based assessment: a weak ecological rationale and insufficient consideration of the role of phytobenthos as a diagnostic tool and for communicating ecosystem health beyond a narrow group of specialists. The papers in the special series allow a comparison with the situation and approaches in the USA, present new methods for the assessment of ecological status and acidification, provide tools for an improved management of headwaters and petrifying springs, discuss the utility of phytobenthos for lake assessments, and test the utility of functional measures (such as biofilm phosphorus uptake capacity, PUC).

  17. A DPSIR model for ecological security assessment through indicator screening: a case study at Dianchi Lake in China.

    Directory of Open Access Journals (Sweden)

    Zhen Wang

    Full Text Available Given the important role of lake ecosystems in social and economic development, and the current severe environmental degradation in China, a systematic diagnosis of the ecological security of lakes is essential for sustainable development. A Driving-force, Pressure, Status, Impact, and Risk (DPSIR model, combined with data screening for lake ecological security assessment was developed to overcome the disadvantages of data selection in existing assessment methods. Correlation and principal component analysis were used to select independent and representative data. The DPSIR model was then applied to evaluate the ecological security of Dianchi Lake in China during 1988-2007 using an ecological security index. The results revealed a V-shaped trend. The application of the DPSIR model with data screening provided useful information regarding the status of the lake's ecosystem, while ensuring information efficiency and eliminating multicollinearity. The modeling approach described here is practical and operationally efficient, and provides an attractive alternative approach to assess the ecological security of lakes.

  18. Multiple stressor effects on water quality in Poplar Bay, Lake of the Woods, Canada: a midge-based assessment of hypolimnetic oxygen conditions over the last two centuries

    Directory of Open Access Journals (Sweden)

    Jamie C. Summers

    2012-01-01

    Full Text Available Chironomid and Chaoborus (midge remains preserved in a dated sediment core from Poplar Bay, Lake of the Woods (LOW, Ontario, Canada, were used to assess the effects of multiple stressors (e.g., recent warming and shoreline development on water quality over the past ~200 years. As monitoring data for LOW do not extend beyond recent decades, paleolimnological methods are used to reconstruct long-term limnological trends and to establish pre-disturbance conditions. The effects of recent warming and shoreline development on Poplar Bay water quality are examined using an index of hypolimnetic oxygen (O2 status based on the ratio of Chaoborus to chironomid remains (chaob:chir and a midge-inferred volume-weighted hypolimnetic oxygen (VWHO model. Our paleolimnological data indicate that hypolimnetic [O2] in Poplar Bay have been historically hypoxic (1-4 mg O2 L-1 but have declined further (generally <2 mg O2 L-1 over the last few decades. Significant relationships between air temperature and midge data indicate that substantial warming starting in the late-1970s has triggered a marked response in the midge assemblages that pre-dates the onset of cottage development (mid-1990s. These findings complement a diatom-based study on the same sediment core, likewise suggesting that recent warming has played a prominent role in structuring limnetic communities. However, it is likely that the full, compounded effects of recent warming and shoreline development have not yet been realized. Our study highlights the complexity of multiple stressor systems, such as Poplar Bay, and emphasizes the benefits of using multiple, independent lines of paleoenvironmental evidence in gaining a more complete understanding of historical water quality.

  19. International Cooperative Programme for Assessment and Monitoring of Acidification of Rivers and Lakes. Programme Manual

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, J.; Forsius, M.; Jeffries, D. [and others

    1996-12-31

    The International Cooperative Programme for Assessment of Acidification of Rivers and lakes (ICP Waters) was established in 1985 by the UN/ECE Executive Body for the Convention of Long-Range Transboundary Air Pollution. Achieving the programme objectives requires that both the temporally intensive and regionally extensive data are collected on a continuing basis. To guide the development and harmonization of the various national contributions, a manual was worked out. The present report is an expanded and consolidated revision of that manual. 33 refs., 3 tabs.

  20. A Conceptual Framework for Assessment of Governance Performance of Lake Basins: Towards Transformation to Adaptive and Integrative Governance

    Directory of Open Access Journals (Sweden)

    Peter Emmanuel Cookey

    2016-03-01

    Full Text Available Governance is essential to lake basin management, but it is the most challenged and needs increased attention. Lake Basin Governance performance assessment is designed to measure the progress and impacts of policies, institutions and the roles of various actors in ensuring sustainability. It measures the performance of technical/operational, social/networks, and institutional arrangement that make up the socio-ecological system. Governance performance assessment becomes very necessary with over-emphasis of institutions on resources utilization and exploitation. The purpose of this paper is to present a governance performance assessment framework specifically for lake basins. The Adaptive Integrated Lake Basin Management (AILBM framework is a diagnostic and prescriptive performance assessment tool with an outcome to produce an adaptive and integrative system with equity, inclusiveness, transparency, accountability and flexibility to problem-solving and resilience. A case study on water governance performance assessment of the Songkhla Lake Basin (SLB in Thailand is provided for illustration and application and indicated a poor performance rating on governance in the Basin, revealing gaps, defects, strengths and weaknesses in the current system, necessary to recommend future improvements.

  1. 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 Lake Tanganyika in spite of the development of mining and smelting 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.

  2. [Characteristics and Risk Assessment of Heavy Metals in Core Sediments from Lakes of Tibet].

    Science.gov (United States)

    Guo, Bi-xi; Liu, Yong-qin; Zhang, Fan; Hou, Ju-zhi; Zhang, Hong-bo

    2016-02-15

    To explore the source of heavy metals in lake sediments and their hazard to environment on Tibetan Plateau, China, heavy metal (Cu, Zn, Cd, Pb, Cr, Co, Ni and As) levels in surface sediments of 18 lakes were investigated. Inductively Coupled Plasma Mass Spectrometry (ICP-MS, X-7 series) was used to determine the contents of heavy metals and the concentrations of carbon and nitrogen in sediment samples were analyzed by element analyzer (Vario Max CN, Elementar, Germany). The average concentrations for Cu, Zn, Cd, Pb, Cr, Co, Ni and As were 24.61 mg x kg(-1), 70.14 mg x kg(-1), 0.26 mg x kg(-1), 25.43 mg x kg(-1), 74.12 mg x kg(-1), 7.93 mg x kg(-1), 33.85 mg x kg(-1), 77.69 mg x kg(-1). It was found that heavy-metal concentrations in Tibet sediments were higher than those in Antarctic, but lower than those in the regions affected by anthropogenic activities. The contents of Cu, Zn, Pb, Cr and Co in the samples were lower than the background values of Tibet. Correlation analysis and principal components analysis (PCA) were used to analyze the origins of heavy metals. The result showed that Cu, Zn, Cd, Pb, Co, Ni and As came from soil in drainage basin and atmospheric deposition. Cr was mainly affected by human activities. Assessment on ecological risk of heavy metals was carried out using Hakanson's method and cluster analysis (CA). Assessment on ecological risk indicated that Pumoyum Co, Longmo Co and Bangong Co were at low risks, Bieruoze Co was at high ecological risk level and the other lakes were at different risk levels. PMID:27363135

  3. AQUATOX coupled foodweb model for ecosystem risk assessment of Polybrominated diphenyl ethers (PBDEs) in lake ecosystems

    International Nuclear Information System (INIS)

    The AQUATOX model considers the direct toxic effects of chemicals and their indirect effects through foodwebs. For this study, the AQUATOX model was applied to evaluating the ecological risk of Polybrominated diphenyl ethers (PBDEs) in a highly anthropogenically disturbed lake-Baiyangdian Lake. Calibration and validation results indicated that the model can adequately describe the dynamics of 18 biological populations. Sensitivity analysis results suggested that the model is highly sensitive to temperature limitation. PBDEs risk estimate results demonstrate that estimated risk for natural ecosystems cannot be fully explained by single species toxicity data alone. The AQUATOX model could provide a good basis in ascertaining ecological protection levels of “chemicals of concern” for aquatic ecosystems. Therefore, AQUATOX can potentially be used to provide necessary information corresponding to early warning and rapid forecasting of pollutant transport and fate in the management of chemicals that put aquatic ecosystems at risk. - Highlights: • AQUATOX model incorporates direct toxic effects and indirect ecological effects. • Ecological risk of PBDEs was assessed by the AQUATOX model. • The model could help determine ecological threshold of “chemicals of concern”. - Capsule abstract: Application of the AQUATOX model to assess the direct and indirect ecological risk of PBDEs

  4. A climatic environmental performance assessment method for ecological city construction:Application to Beijing Yanqi Lake

    Institute of Scientific and Technical Information of China (English)

    FANG Xiao-Yi; CHENG Chen; LIU Yong-Hong; DU Wu-Peng; XIAO Xiao-Jun; DANG Bing

    2015-01-01

    In contrast to the input perspective for evaluating planning metrics, this research takes the climatic environmental output effects as the starting point for assessing ecological city construction. Based on approaches such as observation data analysis, meteorological model simu-lation, and remote sensing, a set of climatic environmental performance assessment methods is developed and established. These methods mainly focus on surface ventilation assessment and urban thermal environment assessment. With the Yanqi Lake ecological development demonstration area located in Huairou district, Beijing as an example, the assessment of the local climatic environment before and after the construction are conducted, and relevant policy suggestions for urban planning and construction are presented. The results show that after development, the ventilation capacity will decrease overall and the ventilation potential index will decrease from 0.53 to 0.44. While this is not a large reduction, and is still at a favorable level, the ventilation potential in some local areas will markedly decrease. Furthermore, the thermal environment will become poorer to some extent;the urban heat island (UHI) area and intensity will increase compared with the current situation;continuous heat islands may occur in local areas;the UHI potential index of the core area will rise from 0.0878 to 0.1217 (still a favorable level). Therefore, urban surfaces should be carefully developed and arranged during planning. It is suggested that the negative impacts of large areas of urban construction on the local climatic environment in the Yanqi Lake could be mitigated by 1) strengthening the airflow by introducing fresh, cold, northwesterly air via constructed ventilation corridors, 2) increasing the number of ecological cold sources, particularly for water bodies and green belts to prevent the UHI in the southern region of Yanqi Lake from becoming linked with each other, and 3) considering a pre-program before

  5. A climatic environmental performance assessment method for ecological city construction: Application to Beijing Yanqi Lake

    Directory of Open Access Journals (Sweden)

    Xiao-Yi Fang

    2015-03-01

    Full Text Available In contrast to the input perspective for evaluating planning metrics, this research takes the climatic environmental output effects as the starting point for assessing ecological city construction. Based on approaches such as observation data analysis, meteorological model simulation, and remote sensing, a set of climatic environmental performance assessment methods is developed and established. These methods mainly focus on surface ventilation assessment and urban thermal environment assessment. With the Yanqi Lake ecological development demonstration area located in Huairou district, Beijing as an example, the assessment of the local climatic environment before and after the construction are conducted, and relevant policy suggestions for urban planning and construction are presented. The results show that after development, the ventilation capacity will decrease overall and the ventilation potential index will decrease from 0.53 to 0.44. While this is not a large reduction, and is still at a favorable level, the ventilation potential in some local areas will markedly decrease. Furthermore, the thermal environment will become poorer to some extent; the urban heat island (UHI area and intensity will increase compared with the current situation; continuous heat islands may occur in local areas; the UHI potential index of the core area will rise from 0.0878 to 0.1217 (still a favorable level. Therefore, urban surfaces should be carefully developed and arranged during planning. It is suggested that the negative impacts of large areas of urban construction on the local climatic environment in the Yanqi Lake could be mitigated by 1 strengthening the airflow by introducing fresh, cold, northwesterly air via constructed ventilation corridors, 2 increasing the number of ecological cold sources, particularly for water bodies and green belts to prevent the UHI in the southern region of Yanqi Lake from becoming linked with each other, and 3 considering a

  6. Assessment of lake sensitivity to acidic deposition in national parks of the Rocky Mountains.

    Science.gov (United States)

    Nanus, L; Williams, M W; Campbell, D H; Tonnessen, K A; Blett, T; Clow, D W

    2009-06-01

    The sensitivity of high-elevation lakes to acidic deposition was evaluated in five national parks of the Rocky Mountains based on statistical relations between lake acid-neutralizing capacity concentrations and basin characteristics. Acid-neutralizing capacity (ANC) of 151 lakes sampled during synoptic surveys and basin-characteristic information derived from geographic information system (GIS) data sets were used to calibrate the statistical models. The explanatory basin variables that were considered included topographic parameters, bedrock type, and vegetation type. A logistic regression model was developed, and modeling results were cross-validated through lake sampling during fall 2004 at 58 lakes. The model was applied to lake basins greater than 1 ha in area in Glacier National Park (n = 244 lakes), Grand Teton National Park (n = 106 lakes), Great Sand Dunes National Park and Preserve (n = 11 lakes), Rocky Mountain National Park (n = 114 lakes), and Yellowstone National Park (n = 294 lakes). Lakes that had a high probability of having an ANC concentration 3000 m, with 80% of the catchment bedrock having low buffering capacity. The modeling results indicate that the most sensitive lakes are located in Rocky Mountain National Park and Grand Teton National Park. This technique for evaluating the lake sensitivity to acidic deposition is useful for designing long-term monitoring plans and is potentially transferable to other remote mountain areas of the United States and the world. PMID:19544737

  7. Assessment of SRTM for studies of deformed lake terraces, Mono Basin, CA, USA

    Science.gov (United States)

    Breier, P.; Bursik, M.; Webb, F.

    2003-04-01

    Mono Lake lies east of the Sierra Nevada, central California, USA. Late Quaternary transgressions and regressions of Mono Lake have produced well-defined terraces within the active and relict shorelands of Mono Basin, as well as on the islands within the lake, including the largest, Paoha Island. To assess the ability of SRTM data to resolve the terraces, we compared the SRTM data to TOPSAR data along topographic profiles. The accuracy of the profiles was assessed by visual and statistical comparison. Information was then extracted from the profiles to determine whether the terraces showed any evidence of warping or offset. Perhaps the most prominent terraces within the basin lie on the eastern and western sides of Paoha Island. When compared with the TOPSAR profiles across these terraces, SRTM profiles are systematically smoother and higher. Comparison of a running average of the TOPSAR data as well as TOPSAR data decimated to 30 m with the SRTM data suggests that much of the SRTM smoothness is the result of the 30 m spacing of the SRTM data as opposed to the 5 m spacing of the TOPSAR data. There is however a mean vertical difference observed between the SRTM and TOPSAR datasets that averages approximately 5 m over a large part of the basin. Near the tops of hills and ridges, the difference between the datasets is less than it is over depressions or areas of low relief. We are investigating the potential causes of the systematic difference. We are exploring the SRTM and TOPSAR data to understand their suitability for determination of deformation of shoreline features. In particular, we are interested in whether magmatic activity beneath the Mono Craters, a volcanic chain on the southern margin of Mono Lake, may be responsible for deformation of a latest Pleistocene(?) terrace at a nominal elevation of 1990 m. The elevation of the bluff-berm break in slope for this terrace was estimated to be at the point of maximum curvature in topographic profiles crossing the

  8. A reappraisal of some Cigar Lake issues of importance to performance assessment

    International Nuclear Information System (INIS)

    The AECL/SKB Cigar Lake Analogue Study was published in 1994. Data from this study, relevant for repository performance assessments, have been reappraised in the light of greater exposure to analogue studies and the development of more realistic models used in performance assessment. Several of the areas proved to have been adequately addressed in the original study, but one of the areas that particularly benefited from the renewed analysis concerned radiolysis. In this case a model for radiolysis was developed and tested, significantly narrowing the gap between calculated and predicted oxidant production. Considerable progress was also made in understanding and modelling the initial formation of the deposit under hydrothermal conditions, and using this conceptual model to evaluate the changes that have subsequently occurred under 'ambient' repository conditions over geological timescales. Moreover, the physical properties of clay as a potential buffer to groundwater flow and radionuclide migration were addressed with some success. 99 refs

  9. Great Lakes Literacy Principles

    Science.gov (United States)

    Fortner, Rosanne W.; Manzo, Lyndsey

    2011-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    None

    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.

  11. Ontario's Quality Assurance Framework: A Critical Response

    Science.gov (United States)

    Heap, James

    2013-01-01

    Ontario's Quality Assurance Framework (QAF) is reviewed and found not to meet all five criteria proposed for a strong quality assurance system focused on student learning. The QAF requires a statement of student learning outcomes and a method and means of assessing those outcomes, but it does not require that data on achievement of intended…

  12. Assessing the variability of glacier lake bathymetries and potential peak discharge based on large-scale measurements in the Cordillera Blanca, Peru

    Science.gov (United States)

    Cochachin, Alejo; Huggel, Christian; Salazar, Cesar; Haeberli, Wilfried; Frey, Holger

    2015-04-01

    Over timescales of hundreds to thousands of years ice masses in mountains produced erosion in bedrock and subglacial sediment, including the formation of overdeepenings and large moraine dams that now serve as basins for glacial lakes. Satellite based studies found a total of 8355 glacial lakes in Peru, whereof 830 lakes were observed in the Cordillera Blanca. Some of them have caused major disasters due to glacial lake outburst floods in the past decades. On the other hand, in view of shrinking glaciers, changing water resources, and formation of new lakes, glacial lakes could have a function as water reservoirs in the future. Here we present unprecedented bathymetric studies of 124 glacial lakes in the Cordillera Blanca, Huallanca, Huayhuash and Raura in the regions of Ancash, Huanuco and Lima. Measurements were carried out using a boat equipped with GPS, a total station and an echo sounder to measure the depth of the lakes. Autocad Civil 3D Land and ArcGIS were used to process the data and generate digital topographies of the lake bathymetries, and analyze parameters such as lake area, length and width, and depth and volume. Based on that, we calculated empirical equations for mean depth as related to (1) area, (2) maximum length, and (3) maximum width. We then applied these three equations to all 830 glacial lakes of the Cordillera Blanca to estimate their volumes. Eventually we used three relations from the literature to assess the peak discharge of potential lake outburst floods, based on lake volumes, resulting in 3 x 3 peak discharge estimates. In terms of lake topography and geomorphology results indicate that the maximum depth is located in the center part for bedrock lakes, and in the back part for lakes in moraine material. Best correlations are found for mean depth and maximum width, however, all three empirical relations show a large spread, reflecting the wide range of natural lake bathymetries. Volumes of the 124 lakes with bathymetries amount to 0

  13. Reforming Ontario Early Learning: A Review

    Science.gov (United States)

    Ryan, Thomas; Date, Gavin

    2014-01-01

    Herein, we address the reformation of Ontario early learning. Over the next 3 years, all 4- and 5-year-olds in Ontario (Canada) will be able to attend full-day early learning with child care, before and after school provided by the Government of Ontario Ministry of Education. The benefits of such a change are both academic and societal and are…

  14. Transmission system planning in Ontario

    Energy Technology Data Exchange (ETDEWEB)

    Barrie, D.; Macedo, F.X.; Mcconnach, J.S. [Ontario Hydro, Toronto, ON (Canada)

    1994-12-31

    In recent years, new and modified approaches to planning the large transmission system that serves the province of Ontario, Canada, have been necessary to accommodate the rapidly changing planning environment including slower uncertain growth, ageing of facilities, integration of demand side management and non utility generation options, increased competitiveness, increased financial stresses and affordable constraints. This paper describes some of the new and modified approaches and tools that have been adopted or are being developed by Ontario Hydro to cope with this changing environment. (author) 9 refs., 4 figs.

  15. Assessment of water-quality conditions in the J.B. Converse Lake watershed, Mobile County, Alabama, 1990-98

    Science.gov (United States)

    Journey, Celeste A.; Gill, Amy C.

    2001-01-01

    Boggy Branch, which had a minimum dissolved-oxygen concentration of 3.7 milligrams per liter. The degree to which nutrient contributions from tributaries were causing nutrient enrichment and eutrophication in Converse Lake was assessed. Trend analysis detected little or no change in nutrient concentrations at the tributary and lake sites in the Converse Lake watershed from the 1991 to 1998 water years. Nutrient concentrations at most tributary sites exhibited a significant, positive relation with streamflow that indicated the dominant source of nutrient input to the watershed is from nonpoint contributions. From 1990 to 1998, computed mean annual loads of 75,400 kilograms of total nitrogen, 36,950 kilograms of total Kjeldahl nitrogen, 28,870 kilograms of total inorganic nitrogen, and 3,480 kilograms of total phosphorus were contributed to the lake by Big Creek, Hamilton Creek, and Crooked Creek combined. These mean annual loads of nutrients corresponded to borderline eutrophic/mesotrophic conditions in the lake. Of the combined loads, 62 percent of the total nitrogen, 70 percent of the total Kjeldahl nitrogen, 54 percent of the total inorganic nitrogen, and 47 percent of the total phosphorus originated from the forested subbasin of Big Creek. The more residential and agricultural subbasins of Crooked Creek and Hamilton Creek, however, yielded over twice the total phosphorus load per hectare of land use. Crooked and Hamilton Creek subbasins also had higher yields of the more bioavailable total inorganic nitrogen. A simplistic empirical model could not explain the relation between year-to-year nutrient contributions to Converse Lake from the tributaries and the lake's ability to assimilate those contributions. The potential presence of pathogens in the lake and its tributaries was assessed based on fecal bacterial concentrations. Fecal bacterial concentrations at some tributary sites were above existing criteria for swimmable uses. Contributions of fecal bacte

  16. 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 < 0.05) between the fluxes of Co, Cu, Mn, Ni, Pb, and Zn and those of iron (Fe) at both sites, (ii) positive correlations (r = 0.82–0.98, p < 0.01, n = 9) between the fluxes of elements (Al, Co, Cu, Fe, Mn, Ni, Pb, and Zn) and the mass accumulation rates at the offshore site, (iii) the low enrichment factors (EF < 5) of those trace elements, and (iv) the temporal consistencies of the isotopic composition of Pb in the sediment. These measurements indicate that accelerated weathering, rather than industrialization, accounts for most of the increases in trace element fluxes to Lake Tanganyika in spite of the development of mining and smelting 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

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

    International Nuclear Information System (INIS)

    Highlights: • Trace element concentrations and lead isotopic ratios were measured in sediment. • Increased element fluxes driven by increased erosion rates linked to land use changes. • Lead isotopic ratios suggest the two sites received lead input from different sources. - Abstract: 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 < 0.05) between the fluxes of Co, Cu, Mn, Ni, Pb, and Zn and those of iron (Fe) at both sites, (ii) positive correlations (r = 0.82–0.98, p < 0.01, n = 9) between the fluxes of elements (Al, Co, Cu, Fe, Mn, Ni, Pb, and Zn) and the mass accumulation rates at the offshore site, (iii) the low enrichment factors (EF < 5) of those trace elements, and (iv) the temporal consistencies of the isotopic composition of Pb in the sediment. These measurements indicate that accelerated weathering, rather than industrialization, accounts for most of the increases in trace element fluxes to Lake Tanganyika in spite

  18. Water Quality Assessment Using Physico-Chemical Parameters and Heavy Metals of Gobind Sagar Lake, Himachal Pradesh (India

    Directory of Open Access Journals (Sweden)

    Vandana Sharma

    2015-12-01

    Full Text Available Today the environment has become harmful for the health of living organisms due to excessive pollution and contamination of natural resources. The present investigation has been carried out with the objective to assess the water quality of the Gobind Sagar Lake, Bilaspur, Himachal Pradesh (India using physico-chemical parameters with heavy metals of the lake. For this study, three sampling sites were identified and samples from different sites were collected in summer season and important parameters [Water Temperature , pH, Total Hardness, Dissolved Carbon Dioxide (CO2, Dissolved Oxygen (DO, Chemical Oxygen Demand (COD, Biological Oxygen Demand (BOD, Chloride, Total Alkalinity, Total Dissolved Solid (TDS] with heavy metals [ Lead (P, Copper (Co, Iron (Fe, Cadmium (Cd, Nickel (Ni and Manganese (Mn, Chromium (Cr were analyzed. The results revealed that the different conditions of Gobind Sagar Lake in different sampling stations showed fluctuations in some physico-chemical parameters and also in heavy metals. These result depicted that water of lake was polluted in the form of nutrient enrichment which is due to agricultural activities and its runoff in and around catchment area of the lake. There are other many ways that things can end up in the lake as the free style way of disposal of industrial and domestic effluents etc. Results of studies on heavy metals in pollution are well documented revealing the toxic effects of these metals on aquatic organisms.

  19. Samuel Wilmot, fish culture, and recreational fisheries in late 19th century Ontario.

    Science.gov (United States)

    Knight, William

    2007-01-01

    Historians have shown that fish culturists and anglers enjoyed a mutually beneficial relationship in 19th century North America. Sharing interests in producing and protecting fish for recreation, the two groups supported emerging regimes of fisheries administration and fish culture that privileged angling and game fish species. In Ontario, it has been argued that anglers achieved control of inland fisheries with help from state fish culturist Samuel Wilmot who, as a sportsman, shared anglers' recreational perspective. A closer look at Wilmot and fish culture in late 19th century Ontario, however, reveals a more complex struggle over recreational fisheries administration. I show that game fish culture under Wilmot was subordinated to fish culture programs that supported the Great Lakes commercial fisheries. Indeed, Wilmot resisted anglers' reframing of Ontario's fisheries as a private recreational resource. By the 1890s, however, this position was unpopular with Ontario's anglers and government officials, who demanded greater provincial control over recreational fisheries and fish culture. It was only after Wilmot's retirement in 1895 that game fish culture received higher priority in Ontario with both federal and provincial governments engaging in programs of wild bass transfers. In 1899, Ontario won a share of fisheries jurisdiction and established its first provincial fisheries administration, which laid the basis for more comprehensive programs of game fish culture in the 20th century. PMID:19227681

  20. Assessing variability of water quality in a groundwater-fed perennial lake of Kashmir Himalayas using linear geostatics

    Indian Academy of Sciences (India)

    S Sarah; Gh Jeelani; Shakeel Ahmed

    2011-06-01

    This paper presents a study on Manasbal lake, which is one of the high altitude lakes in the KashmirValley, India. Eighteen water samples were analysed for major ions and trace elements to assess the variability of water quality of the lake for various purposes. Geostatistics, the theory of regionalized variables, was then used to enhance the dataset and estimate some missing spatial values. Resultsindicated that the concentration of major ions in the water samples in winter was higher than in summer. The scatter diagrams suggested the dominance of alkaline earths over the alkali elements. Three types of water were identified in the lake that are referred to as Ca–HCO3, Mg–HCO3 and hybrid types. The lake water was found to be controlled by rock–water interaction with carbonate lithology as a dominant source of the solutes. The major (Ca2+, Mg2+, Na+, K+, NO3 and HCO$^{−}_{3}$, CO3 and Cl) and trace elements of the lake water were within the World Health Organization standards, therefore the lake water was considered chemically safe for drinking purposes. Although NO3 concentration (ranging from 1.72 to 2 mg/L), is within the permissible limit and not very alarming, the gradually increasing trend is not acceptable. It is however, important to guard its spatio-temporal variability as the water is used for domestic as well as agricultural purposes. This study is significant as hydrogeological information on such high altitude lakes in India is scanty.

  1. Real-time assessments of water quality: expanding nowcasting throughout the Great Lakes

    Science.gov (United States)

    ,

    2013-01-01

    Nowcasts are systems that inform the public of current bacterial water-quality conditions at beaches on the basis of predictive models. During 2010–12, the U.S. Geological Survey (USGS) worked with 23 local and State agencies to improve existing operational beach nowcast systems at 4 beaches and expand the use of predictive models in nowcasts at an additional 45 beaches throughout the Great Lakes. The predictive models were specific to each beach, and the best model for each beach was based on a unique combination of environmental and water-quality explanatory variables. The variables used most often in models to predict Escherichia coli (E. coli) concentrations or the probability of exceeding a State recreational water-quality standard included turbidity, day of the year, wave height, wind direction and speed, antecedent rainfall for various time periods, and change in lake level over 24 hours. During validation of 42 beach models during 2012, the models performed better than the current method to assess recreational water quality (previous day's E. coli concentration). The USGS will continue to work with local agencies to improve nowcast predictions, enable technology transfer of predictive model development procedures, and implement more operational systems during 2013 and beyond.

  2. Contamination and risk assessment of heavy metals in bottom sediments from Lake Valencia, Venezuela

    Directory of Open Access Journals (Sweden)

    González A.

    2013-04-01

    Full Text Available The contamination and risk assessment of heavy metals in the bottom sediments of the Lake Valencia, Venezuela, was performed by determining the Enrichment Factor (EF, the Geoaccumulation Factor (Igeo, the availability of metals and the Risk Index Code (RAC. The sediments were anthropogenic ally enriched with Pb, Zn, Cu and Cr and classified as uncontaminated to moderately contaminated, with a medium risk of Zn, Co, Ni and Cr, and low risk of Cu, Pb and Cd. Analysis of correlations and PCA showed temporal variations in the concentration of metals in the sediments during the rainy season, and spatial variations, where the depth and anthropogenic inputs are the main variables. The contamination of sediments was located on the axis connecting the mouths of the river Guayos, which crosses the city of Valencia, and the river Güey which crosses the city of Maracay, both highly industrialized. Although the concentration of dissolved heavy metals into the waters was within the regulations, important concentrations of Pb and Hg and the bioaccumulation of Hg and Cr, determined by the Bioconcentration Factor (BCF, were found in the fish tissues which indicate that the metal enrichment of the lake sediments is affecting the biota.

  3. A Multiscale Mapping Assessment of Lake Champlain Cyanobacterial Harmful Algal Blooms.

    Science.gov (United States)

    Torbick, Nathan; Corbiere, Megan

    2015-09-01

    Lake Champlain has bays undergoing chronic cyanobacterial harmful algal blooms that pose a public health threat. Monitoring and assessment tools need to be developed to support risk decision making and to gain a thorough understanding of bloom scales and intensities. In this research application, Landsat 8 Operational Land Imager (OLI), Rapid Eye, and Proba Compact High Resolution Imaging Spectrometer (CHRIS) images were obtained while a corresponding field campaign collected in situ measurements of water quality. Models including empirical band ratio regressions were applied to map chlorophylla and phycocyanin concentrations; all sensors performed well with R² and root-mean-square error (RMSE) ranging from 0.76 to 0.88 and 0.42 to 1.51, respectively. The outcomes showed spatial patterns across the lake with problematic bays having phycocyanin concentrations >25 μg/L. An alert status metric tuned to the current monitoring protocol was generated using modeled water quality to illustrate how the remote sensing tools can inform a public health monitoring system. Among the sensors utilized in this study, Landsat 8 OLI holds the most promise for providing exposure information across a wide area given the resolutions, systematic observation strategy and free cost. PMID:26389930

  4. A Multiscale Mapping Assessment of Lake Champlain Cyanobacterial Harmful Algal Blooms

    Directory of Open Access Journals (Sweden)

    Nathan Torbick

    2015-09-01

    Full Text Available Lake Champlain has bays undergoing chronic cyanobacterial harmful algal blooms that pose a public health threat. Monitoring and assessment tools need to be developed to support risk decision making and to gain a thorough understanding of bloom scales and intensities. In this research application, Landsat 8 Operational Land Imager (OLI, Rapid Eye, and Proba Compact High Resolution Imaging Spectrometer (CHRIS images were obtained while a corresponding field campaign collected in situ measurements of water quality. Models including empirical band ratio regressions were applied to map chlorophylla and phycocyanin concentrations; all sensors performed well with R2 and root-mean-square error (RMSE ranging from 0.76 to 0.88 and 0.42 to 1.51, respectively. The outcomes showed spatial patterns across the lake with problematic bays having phycocyanin concentrations >25 μg/L. An alert status metric tuned to the current monitoring protocol was generated using modeled water quality to illustrate how the remote sensing tools can inform a public health monitoring system. Among the sensors utilized in this study, Landsat 8 OLI holds the most promise for providing exposure information across a wide area given the resolutions, systematic observation strategy and free cost.

  5. Assessment of Reservoir Water Quality Using Multivariate Statistical Techniques: A Case Study of Qiandao Lake, China

    Directory of Open Access Journals (Sweden)

    Qing Gu

    2016-03-01

    Full Text Available Qiandao Lake (Xin’an Jiang reservoir plays a significant role in drinking water supply for eastern China, and it is an attractive tourist destination. Three multivariate statistical methods were comprehensively applied to assess the spatial and temporal variations in water quality as well as potential pollution sources in Qiandao Lake. Data sets of nine parameters from 12 monitoring sites during 2010–2013 were obtained for analysis. Cluster analysis (CA was applied to classify the 12 sampling sites into three groups (Groups A, B and C and the 12 monitoring months into two clusters (April-July, and the remaining months. Discriminant analysis (DA identified Secchi disc depth, dissolved oxygen, permanganate index and total phosphorus as the significant variables for distinguishing variations of different years, with 79.9% correct assignments. Dissolved oxygen, pH and chlorophyll-a were determined to discriminate between the two sampling periods classified by CA, with 87.8% correct assignments. For spatial variation, DA identified Secchi disc depth and ammonia nitrogen as the significant discriminating parameters, with 81.6% correct assignments. Principal component analysis (PCA identified organic pollution, nutrient pollution, domestic sewage, and agricultural and surface runoff as the primary pollution sources, explaining 84.58%, 81.61% and 78.68% of the total variance in Groups A, B and C, respectively. These results demonstrate the effectiveness of integrated use of CA, DA and PCA for reservoir water quality evaluation and could assist managers in improving water resources management.

  6. Heavy metal Assessment and Their Speciation in Sediments of Lake Chapala, Mexico.

    Science.gov (United States)

    Gomez-Salazar, S.; Zarate-Del Valle, P. F.; Rios-Donato, N.; Mendizabal-Mijares, E.; Saucedo-Torres, N. P.; Trujillo-Cardenas, J. L.

    2007-12-01

    The presence of heavy metals Cd, Pb, Mn, Cr, Fe, Ni, Cu, and Zn in waters and the speciation of Cd, Pb, Cr, Ni, Cu, and Zn in sediments of several sites of the Mexican Lake Chapala as well as some physicochemical parameters reflecting water quality, are presented here. The sites were sampled on March 2007. Metals in sediments and their partition into chemical species was determined between five geochemical phases (exchangeable, carbonates, Fe/Mn oxides, organic matter and residuals) applying the Tessier' s sequential extraction technique. Sediment cores (n=10) taken from the depocenter between the years of 1998 and 1999 allowed evaluation of sediment uniformity (geochemistry, mineralogy and particle distribution). Cadmium, lead and chromium were found to be present significantly in both exchangeable and carbonate fractions in two sites indicating that these metals were introduced to the lake via anthropogenic activities during the period of 1960 through the first quarter of 2006. The Risk Assessment Code was applied to the two sites studied and it was found that both sites pose a high level risk of pollution since the metals bound to exchangeable and carbonate fractions in the cases of Pb and Cd comprise > 45%.

  7. [Ontario Hydro]. Corporate performance report, 1994

    International Nuclear Information System (INIS)

    Summarizes Ontario Hydro's corporate performance for the year, with actual results being compared against planned values. Also includes additional indicators that illustrate noteworthy trends in corporate performance. Corporate results are reported under the new organizational structure implemented in 1993, beginning with overall results in such areas as customer service, environmental stewardship, human resources, and finance. This is followed by reports from the Generation Business Group, Customer Services Group, Corporate Business Group, General Counsel and Secretary, Ontario Hydro Audit, Strategic Planning, Environment and Communication Group, and Ontario Hydro enterprises (Ontario Hydro Technologies, Ontario Hydro International). The appendix includes summary financial statements

  8. Hazard Assessment of Glacial Lake Outburst Flood and Potential of ICTs for Coping: A Case of Eastern Himalaya of Nepal

    Science.gov (United States)

    Bhattarai, D. R.

    2015-12-01

    Retreat of glaciers and formation of glacial lakes in Nepal Himalaya have been reported to be related with the temperature rise in the region. Glacier Lake Outburst Floods (GLOF) are the growing climate induced hazards in the Himalaya. GLOF has increased the vulnerability of community and fragile ecosystem in the mountain valleys. This study has analyzed the potential impacts from GLOF in the highland of eastern Nepal and the potential role of Information Communication Technologies (ICT) to cope with such impacts. I analyzed the trend of climatic pattern (temperature and precipitation) of the Eastern Himalaya Region of Nepal available from the Department of Hydrology and Meteorology, Government of Nepal, and prepared the latest location map of the glacial lakes using google earth and ArcGIS applications in the highland of the Kanchanjungha Conservation Area of the region. Tiptala glacial lake, located at an elevation of 4950 m, within the conservation area, was selected for the GLOF hazard assessment. I used semi-structured questionnaire survey and key informants' interviews in the community in order to assess the potential hazard of GLOF. With the varying sizes, 46 glacial lakes were located in the region, which covers over 2.57 sq. km in total. Though the larger portion of the downstream area of the Tiptala glacial lake fall in the remote location away from major residential area, few villages, major pasture lands for Yaks, foot trails, and several bridges across the Tamor River below the lake are in risk of GLOF. Poor access due to extreme geographical remoteness and capacity to afford the modern technologies in the community are the major limiting factor to the knowledge and information about the climate change and related impacts. Modern ICTs has high potential to reduce the risk of climate related hazards in the remote area by information dissemination and awareness.

  9. Lake Roosevelt Fisheries Evaluation Program, Assessment of the Lake Roosevelt Walleye Population 1998 Annual Report, Part D.

    Energy Technology Data Exchange (ETDEWEB)

    McLellan, Jason G.; Moffatt, Holly J.; Scholz, Allan T.

    1999-08-01

    A walleye mark-recapture experiment was initiated on Lake Roosevelt in 1997, with the primary objective of estimating the size of the walleye population. The project was continued in 1998 with a revised sampling regime. The primary goals during 1998 were to estimate the size of the walleye population in Lake Roosevelt, estimate the size of the spawning run in the Spokane River Arm, and describe the age structure of the population for use in managing the population and developing a kokanee bioenergetics model. Secondary objectives included: determining walleye movements, back-calculating growth rates, estimating mortality rates, determining walleye condition, and estimating walleye young-of-the-year (YOY) production in the Spokane River Arm. All walleye, {ge} 150 mm TL, were marked with individually numbered Floy{reg_sign} tags, during five passes through the reservoir. The passes occurred between April 1st and September 16th, 1998. The most unbiased estimate of walleye abundance in Lake Roosevelt, 186,482 (40,113 {le} N {le} 943,213), was obtained using the Mtb model of the CAPTURE program. The most unbiased estimate of the size of the walleye spawning run in the Spokane River Arm, 27,345 (1,535 {le} N {le} 57,519), was calculated using the Jolly-Seber model. The abundance estimates appeared reasonable, but they had wide 95 % confidence intervals. Wide confidence intervals were attributed to low capture probabilities. Coefficient of variation (CV) values for both estimates indicated that they were not acceptable for general management, not to mention research. Despite the CV value, we felt that the reservoir estimate was reasonable and that it was the best possible, without a large increase in effort and money. The spawning run estimate could have been improved by a small increase in effort. Ages of walleye in Lake Roosevelt ranged from 0 to 13 years. Growth, mortality, and condition were all average when compared to other walleye producing waters. We recommended

  10. Simulation of Heavy Lake-Effect Snowstorms across the Great Lakes Basin by RegCM4

    Science.gov (United States)

    Notaro, M.; Zarrin, A.; Vavrus, S. J.; Bennington, V.

    2013-12-01

    A historical simulation (1976-2002) of the Abdus Salam International Centre for Theoretical Physics Regional Climate Model Version 4 (ICTP RegCM4), coupled to a one-dimensional lake model, is validated against observed lake ice cover and snowfall across the Great Lakes Basin. The model reproduces the broad temporal and spatial features of both variables in terms of spatial distribution, seasonal cycle, and interannual variability, including climatological characteristics of lake-effect snowfall, although the simulated ice cover is overly extensive largely due to the absence of lake circulations. A definition is introduced for identifying heavy lake-effect snowstorms in regional climate model output for all grid cells in the Great Lakes Basin, using criteria based on location, wind direction, lake ice cover, and snowfall. Simulated heavy lake-effect snowstorms occur most frequently downwind of the Great Lakes, particularly to the east of Lake Ontario and to the east and south of Lake Superior, and are most frequent in December-January. The mechanism for these events is attributed to an anticyclone over the central United States and related cold air outbreak for areas downwind of Lakes Ontario and Erie, in contrast to a nearby cyclone over the Great Lakes Basin and associated cold front for areas downwind of Lakes Superior, Huron, and Michigan. Projections of mid- and late-21st century lake-effect snowstorms in the Great Lakes Basin will be summarized, based on dynamically downscaled CMIP5 (Coupled Model Intercomparison Project Phase Five) simulations.

  11. Ontario Hydro annual report 1986

    International Nuclear Information System (INIS)

    Ontario Hydro's annual report of the financial position and activities for the year 1986 consists of their financial highlights; corporate profile; customer service and satisfaction; message from Chairman; message from President; 1986 in review; financial section; management report; five-year summary of financial statistics; and comparative statistics

  12. Development of a Zooplankton Assemblage Indicator for the 2012 National Lakes Assessment: Performance in the Western U.S.

    Science.gov (United States)

    We used zooplankton count data collected as part of the 2012 National Lakes Assessment (NLA) to develop candidate metrics and multimetric indices (MMIs) for five aggregated ecoregions of the conterminous USA (Coastal Plains, Eastern Highlands, Plains, Upper Midwest, and Western M...

  13. Can a rapid underwater video approach enhance the benthic assessment capability of the National Coastal Condition Assessmentin the Great Lakes?

    Science.gov (United States)

    In the U.S. National Coastal Condition Assessment (NCCA) field survey in summer 2010, over 400 sites in the nearshore zone of the U.S. Great Lakes were sampled. As a supplement to core NCCA benthic taxonomy and sediment chemistry, underwater video images of the bottom condition ...

  14. Detection of microcystins in Pamvotis lake water and assessment of cyanobacterial bloom toxicity.

    Science.gov (United States)

    Papadimitriou, Theodoti; Armeni, Euthimia; Stalikas, Constantine D; Kagalou, Ifigeneia; Leonardos, Ioannis D

    2012-05-01

    Lake Pamvotis is a shallow, eutrophic Mediterranean lake with ecological significance. This paper deals with the evaluation of cyanobacterial toxicity in Lake Pamvotis. ELISA and HPLC revealed the presence of significant amounts of MCYST-LR. Danio rerio bioassay confirmed the toxic nature of the bloom. Cyanobacterial extracts had adverse toxic effects on development of D. rerio. Also, it was shown that cyanobacterial extracts containing environmentally detected concentrations of MCYST can cause reduced survival rate of fish species. The results clearly indicate that cyanobacterial blooms in Lake Pamvotis may be regarded as human and fish health hazard. Continuous monitoring of the lake is suggested, in order to prevent future possible intoxications. PMID:21713485

  15. A GIS method for assessment of rock slide tsunami hazard in Norwegian lakes and reservoirs

    OpenAIRE

    Romstad, B.; Harbitz, C. B.; U. Domaas

    2009-01-01

    An evaluation of rock slide tsunami hazard is applied to all Norwegian lakes larger than 0.1 km2 based on their topographical setting. The analysis results in a topographic rock slide potential score that indicates the relative hazard in each lake. Even though the score value each lake receives should be interpreted with caution, the distribution of score values shows that we are able to make a clear distinction between lakes with a high vs. lakes with a low hazard. The...

  16. Reconstruction of glacial lake outburst floods in northern Tien Shan: Implications for hazard assessment

    Science.gov (United States)

    Zaginaev, V.; Ballesteros-Cánovas, J. A.; Erokhin, S.; Matov, E.; Petrakov, D.; Stoffel, M.

    2016-09-01

    Glacier lake outburst floods (GLOFs) and related debris flows are among the most significant natural threats in the Tien Shan Mountains of Kyrgyzstan and have even caused the loss of life and damage to infrastructure in its capital Bishkek. An improved understanding of the occurrence of this process is essential so as to be able to design reliable disaster risk reduction strategies, even more so in view of ongoing climate change and scenarios of future evolutions. Here, we apply a dendrogeomorphic approach to reconstruct past debris-flow activity on the Aksay cone (Ala-Archa valley, Kyrgyz range), where outbursting glacier lakes and intense rainfalls have triggered huge debris flows over the past decades. A total of 96 Picea abies (L.) Karst. trees growing on the cone and along the main channel have been selected based on the evidence of past debris-flow damage in their trunks; these trees were then sampled using increment borers. The dating of past events was based on the assessment of growth disturbances (GD) in the tree-ring records and included the detection of injuries, tangential rows of traumatic resin ducts, reaction wood, and abrupt growth changes. In total, 320 GD were identified in the tree-ring samples. In combination with aerial imagery and geomorphic recognition in the field, reactions in trees and their position on the cone have allowed reconstruction of the main spatial patterns of past events on the Aksay cone. Our findings suggest that at least 27 debris flows have occurred on the site between 1877 and 2015 and point to the occurrence of at least 17 events that were not documented prior to this study. We also observe high process activity during the 1950s and 1960s, with major events on the cone in 1950, 1966, and 1968, coinciding with phases of slight glacier advance. The spatial analyses of events also point to two different spatial patterns, suggesting that quite dissimilar magnitudes probably occurred during glacier lake outburst floods and

  17. In-situ characterization and assessment of arsenic mobility in lake sediments.

    Science.gov (United States)

    Sun, Qin; Ding, Shiming; Wang, Yan; Xu, Lv; Wang, Dan; Chen, Jing; Zhang, Chaosheng

    2016-07-01

    In-situ characterization and assessment of arsenic (As) mobility in sediments was scarce. In this study, the distributions of labile As at a vertical resolution of 2 mm were obtained in the sediments of a large Lake Taihu through in-situ measurements using a Zr-oxide diffusive gradients in thin films (Zr-oxide DGT) technique. The DGT-labile As, interpreted as DGT flux (FDGT), exhibited three different patterns in the lake, with all the patterns generally showing an increasing mobility followed by a decreasing mobility with sediment depth. The mobility of As could be characterized by the average FDGT (0.06-1.27 pg cm(-2) s(-1)) in the top 10 mm surface sediments, the maximal FDGT (FDGT-M, 0.14-2.44 pg cm(-2) s(-1)) in the end of the initial increasing phase of FDGT, and the diffusion length (ΔL, 28-66 mm) from the depth showing the FDGT-M to the sediment-water interface. The upward mobilization of labile As from the deep sediments to the surface sediments and overlying water became evident when FDGT-M > 1.7 pg cm(-2) s(-1) or ΔL < 41 mm. The results, for the first time, showed a prospect in in-situ risk assessment of the pollution of sediment As. It was suggested that the increasing mobility of As in the upper sediments was controlled by the reduction of As(V) and the reductive dissolution of Fe(III) (hydr)oxides, while the decreasing mobility in the deep sediments was attributed to immobilization of As(III) by secondary Fe(II)-bearing minerals. PMID:27107255

  18. A Atmospheric Dispersion Model for the Sudbury, Ontario, Area.

    Science.gov (United States)

    Huhn, Frank Jones

    1982-03-01

    A mathematical model was developed and tested to predict the relationship between sulphur oxide and trace metal emissions from smelters in the Sudbury, Ontario area, and atmospheric, precipitation, lake water and sediment chemistry. The model consists of atmospheric and lake chemistry portions. The atmospheric model is a Gaussian crosswind concentration distribution modification to a box model with a uniform vertical concentration gradient limited by a mixing height. In the near-field Briggs' plume rise and vertical dispersion terms are utilized. Oxidation, wet and dry deposition mechanisms are included to account for the gas, liquid and solid phases separately. Important improvements over existing models include (1) near- and far-field conditions treated in a single model; (2) direct linkage of crosswind dispersion to hourly meteorological observations; (3) utilization of maximum to minimum range of input parameters to realistically model the range of outputs; (4) direct linkage of the atmospheric model to a lake model. Precipitation chemistry as calculated by the atmospheric model is related to lake water and sediment chemistry utilizing a mass balance approach and assuming a continuously stirred reactor (CSTR) model to describe lake circulation. All inputs are atmospheric, modified by hydrology, soil chemistry and sedimentation. Model results were tested by comparison with existing atmospheric and precipitation chemistry measurements, supplemented with analyses of lake water and sediment chemistry collected in a field program. Eight pollutant species were selected for modeling: sulphur dioxide, sulphate ion, hydrogen ion, copper, nickel, lead, zinc, and iron. The model effectively predicts precipitation chemistry within 150 km of Sudbury, with an average prediction to measurement ratio of 90 percent. Atmospheric concentrations are effectively predicted within 80 km, with an average prediction to measurement ratio of 81 percent. Lake chemistry predictions are

  19. A GIS method for assessment of rock slide tsunami hazard in all Norwegian lakes and reservoirs

    Directory of Open Access Journals (Sweden)

    B. Romstad

    2009-03-01

    Full Text Available An evaluation of rock slide tsunami hazard is applied to all Norwegian lakes larger than 0.1 km2 based on their topographical setting. The analysis results in a topographic rock slide potential score that indicates the relative hazard in each lake. Even though the score value each lake receives should be interpreted with caution, the distribution of score values shows that we are able to make a clear distinction between lakes with a high vs. lakes with a low hazard. The results also show a clustering of threatened lakes in parts of Western Norway as well as some locations in Northern Norway. This makes the results useful as a tool for focusing further studies on regions or specific lakes that received high scores. The results also show how the method may be used for more detailed analysis of a given lake (or fjord. Maps can be produced that may serve as a guide when carrying out field campaigns or when designing scenarios for numerical simulations of tsunamis in the lake. It should be emphasised that the rock slide potential reported for each lake is based on the topographical setting alone and hence, does not represent the actual probability of rock slides into the lakes. For a given area, more detailed investigations of the geology, triggering factors and frequency of previous rock slide events should be carried out before definite statements about the actual hazard can be made.

  20. Rare-earths and trace elements in Temsah Lake sediments. A tool to assess pollution sources in the lake

    International Nuclear Information System (INIS)

    Rare-earths and trace elements content in Temsah lake sediments (Ismailia Governorate, Egypt) were investigated. Eight polluted sites were selected and sediment samples were seasonally collected, dried, grounded and prepared for neutron activation analysis (NAA). Fourteen elements were determined (i.e.Sc, Cr, Ba, La, Hf, Sb, Ce, Eu,Tb,Yb, Ta, Pa, Au, and Hg) in sediment samples of different sites. The gamma-ray spectra was collected by HPGe detector and the analysis was done by means of computerized multichannel analyzer. A stepwise regression analysis for significant relationship between tested elements across all sites was discussed. Also, a correlation matrix between elemental contents of different sites was made

  1. Hydrological, chemical, and isotopic budgets of Lake Chad: a quantitative assessment of evaporation, transpiration and infiltration fluxes

    Science.gov (United States)

    Bouchez, Camille; Goncalves, Julio; Deschamps, Pierre; Vallet-Coulomb, Christine; Hamelin, Bruno; Doumnang, Jean-Claude; Sylvestre, Florence

    2016-04-01

    In the Sahelian belt, Lake Chad is a key water body for 13 million people, who live on its resources. It experiences, however, substantial and frequent surface changes. Located at the centre of one of the largest endorheic basins in the world, its waters remain surprisingly fresh. Its low salinity has been attributed to a low infiltration flow whose value remains poorly constrained. Understanding the lake's hydrological behaviour in response to climate variability requires a better constraint of the factors that control its water and chemical balance. Based on the three-pool conceptualization of Lake Chad proposed by Bader et al. (2011), this study aims to quantify the total water outflow from the lake, the respective proportions of evaporation (E), transpiration (T), and infiltration (I), and the associated uncertainties. A Bayesian inversion method based on lake-level data was used, leading to total water loss estimates in each pool (E + T + I = ETI). Sodium and stable isotope mass balances were then used to separate total water losses into E, T, and I components. Despite the scarcity of representative data available on the lake, the combination of these two geochemical tracers is relevant to assess the relative contribution of these three outflows involved in the control of the hydrological budget. Mean evapotranspiration rates were estimated at 2070 ± 100 and 2270 ± 100 mm yr-1 for the southern and northern pools, respectively. Infiltration represents between 100 and 300 mm yr-1 but most of the water is evapotranspirated in the first few kilometres from the shorelines and does not efficiently recharge the Quaternary aquifer. Transpiration is shown to be significant, around 300 mm yr-1 and reaches 500 mm yr-1 in the vegetated zone of the archipelagos. Hydrological and chemical simulations reproduce the marked hydrological change between the normal lake state that occurred before 1972 and the small lake state after 1972 when the lake surface shrunk to a one

  2. Hydroacoustic estimates of abundance and spatial distribution of pelagic prey fishes in western Lake Superior

    Science.gov (United States)

    Mason, Doran M.; Johnson, Timothy B.; Harvey, Chris J.; Kitchell, James F.; Schram, Stephen T.; Bronte, Charles R.; Hoff, MIchael H.; Lozano, Stephen J.; Trebitz, Anett S.; Schreiner, Donald R.; Lamon, E. Conrad; Hrabik, Thomas R.

    2005-01-01

    Lake herring (Coregonus artedi) and rainbow smelt (Osmerus mordax) are a valuable prey resource for the recovering lake trout (Salvelinus namaycush) in Lake Superior. However, prey biomass may be insufficient to support the current predator demand. In August 1997, we assessed the abundance and spatial distribution of pelagic coregonines and rainbow smelt in western Lake Superior by combining a 120 kHz split beam acoustics system with midwater trawls. Coregonines comprised the majority of the midwater trawl catches and the length distributions for trawl caught fish coincided with estimated sizes of acoustic targets. Overall mean pelagic prey fish biomass was 15.56 kg ha−1 with the greatest fish biomass occurring in the Apostle Islands region (27.98 kg ha−1), followed by the Duluth Minnesota region (20.22 kg ha−1), and with the lowest biomass occurring in the open waters of western Lake Superior (9.46 kg ha−1). Biomass estimates from hydroacoustics were typically 2–134 times greater than estimates derived from spring bottom trawl surveys. Prey fish biomass for Lake Superior is about order of magnitude less than acoustic estimates for Lakes Michigan and Ontario. Discrepancies observed between bioenergetics-based estimates of predator consumption of coregonines and earlier coregonine biomass estimates may be accounted for by our hydroacoustic estimates.

  3. Assessing potential impacts of climate change and variability on the Great Lakes-St. Lawrence Basin: A binational approach

    International Nuclear Information System (INIS)

    The potential impacts of climate change and variability on the Great Lakes environment are serious and complex. The Great Lakes-St. Lawrence Basin is home to 42.5 million US and Canadian citizens and is the industrial and commercial heartland of both nations. The region is rich in human and natural resources, with diverse economic activities and substantial infrastructure which would be affected by major shifts in climate. For example, water level changes could affect wetland distribution and functioning; reductions in streamflow would alter assimilative capacities while warmer water temperatures would influence spring and fall turnover and incidence of anoxia. A binational program has been initiated to conduct interdisciplinary, integrated impact assessments for the Great Lakes-St. Lawrence River Basin. The goal of this program is to undertake interdisciplinary, integrated studies to improve the understanding of the complex interactions between climate, the environment, and socioeconomic systems in order to develop informed regional adaptation responses

  4. Assessing Climate Change Effect on the World's Largest Lakes Using Satellite Observation

    Science.gov (United States)

    Wang, C.; Gabriel, R.; Norouzi, H.

    2014-12-01

    The Landsat program offers the longest continuous global record of the Earth's surface using satellite imagery for over forty years (1972-2014). Millions of images and relevant data have since been acquired using the instrument on the Landsat satellite to monitor the Earth's interesting phenomena. There are Landsat receiving stations around the world including the United States that process and archive the images that are a unique resource for global change research and applications in agriculture, forestry, regional planning, geology, cartography and global warming. So far, National Oceanic Atmospheric and Administration (NOAA) and National Aeronautics and Space Administration (NASA), have launched a total of eight successfully orbiting satellites throughout its forty-two years of service. The main objective of this project aims to use Landsat images to monitor the changes of the world's largest lakes from 1972 to present. We focus on areas around the planet that are home to large scale lakes such as Lake Urmia, Lake Vanern, Lake Winnipegosis, Lake Albert and Lake Mweru. Then using U.S Geological Survey (USGS) database as a source for gathering cloud free images that are covering each lake, we were able to download and obtain necessary data. For larger lakes, images were mosaic to cover the entire area of the lake and using a Maximum Likelihood technique images were specifically classified into land and water content using ENVI software. The extent of the water content was quantified for each year and a temporal analysis of the area was performed. It is also found that the lakes which locates near the equator or at low latitude are seriously facing threats of becoming mostly dry. Future work is needed for establishing the dynamic characteristic of more lakes' water extent changes and also to compare them with other available information such as precipitation and soil moisture in each region. In lakes where high latitude, the change in extent of ice during winter

  5. A freshwater biodiversity hotspot under pressure – assessing threats and identifying conservation needs for ancient Lake Ohrid

    Directory of Open Access Journals (Sweden)

    G. Kostoski

    2010-12-01

    Full Text Available Immediate conservation measures for world-wide freshwater resources are of eminent importance. This is particularly true for so-called ancient lakes. While these lakes are famous for being evolutionary theatres, often displaying an extraordinarily high degree of biodiversity and endemism, in many cases these biota are also experiencing extreme anthropogenic impact.

    Lake Ohrid, a major European biodiversity hotspot situated in a trans-frontier setting on the Balkans, is a prime example for a lake with a magnitude of narrow range endemic taxa that are under increasing anthropogenic pressure. Unfortunately, evidence for a "creeping biodiversity crisis" has accumulated over the last decades, and major socio-political changes have gone along with human-mediated environmental changes.

    Based on field surveys, monitoring data, published records, and expert interviews, we aimed to (1 assess threats to Lake Ohrids' (endemic biodiversity, (2 summarize existing conservation activities and strategies, and (3 outline future conservation needs for Lake Ohrid. We compiled threats to both specific taxa (and in cases to particular species as well as to the lake ecosystems itself. Major conservation concerns identified for Lake Ohrid are: (1 watershed impacts, (2 agriculture and forestry, (3 tourism and population growth, (4 non-indigenous species, (5 habitat alteration or loss, (6 unsustainable exploitation of fisheries, and (7 global climate change.

    Among the major (well-known threats with high impact are nutrient input (particularly of phosphorus, habitat conversion and silt load. Other threats are potentially of high impact but less well known. Such threats include pollution with hazardous substances (from sources such as mines, former industries, agriculture or climate change. We review and discuss institutional responsibilities, environmental monitoring and ecosystem management, existing parks and reserves, biodiversity and species

  6. A freshwater biodiversity hotspot under pressure – assessing threats and identifying conservation needs for ancient Lake Ohrid

    Directory of Open Access Journals (Sweden)

    G. Kostoski

    2010-07-01

    Full Text Available Freshwater habitats and species living in freshwater are generally more prone to extinction than terrestrial or marine ones. Immediate conservation measures for world-wide freshwater resources are thus of eminent importance. This is particularly true for so called ancient lakes. While these lakes are famous for being evolutionary theatres, often displaying an extraordinarily high degree of biodiversity and endemism, in many cases these biota are also experiencing extreme anthropogenic impact.

    Lake Ohrid, the European biodiversity hotspot, is a prime example for a lake with a magnitude of narrow range endemic taxa that are under increasing anthropogenic pressure. Unfortunately, evidence for a "creeping biodiversity crisis" has accumulated over the last decades, and major socio-political changes have gone along with human-mediated environmental changes.

    Based on field surveys, monitoring data, published records, and expert interviews, we aimed to (1 assess threats to Lake Ohrids' (endemic biodiversity, (2 summarize existing conservation activities and strategies, and (3 outline future conservation needs for Lake Ohrid. We compiled threats to both specific taxa (and in cases to particular species as well as to the lake ecosystems itself. Major conservation concerns identified for Lake Ohrid are: (1 watershed impacts, (2 agriculture and forestry, (3 tourism and population growth, (4 non-indigenous species, (5 habitat alteration or loss, (6 unsustainable exploitation of fisheries, and (7 global climate change.

    Of the 11 IUCN (International Union for Conservation of Nature and Natural Resources threat classes scored, seven have moderate and three severe impacts. These latter threat classes are energy production and mining, biological resource use, and pollution. We review and discuss institutional responsibilities, environmental monitoring and ecosystem management, existing parks and reserves, biodiversity and species

  7. In-situ characterization and assessment of arsenic mobility in lake sediments.

    Science.gov (United States)

    Sun, Qin; Ding, Shiming; Wang, Yan; Xu, Lv; Wang, Dan; Chen, Jing; Zhang, Chaosheng

    2016-07-01

    In-situ characterization and assessment of arsenic (As) mobility in sediments was scarce. In this study, the distributions of labile As at a vertical resolution of 2 mm were obtained in the sediments of a large Lake Taihu through in-situ measurements using a Zr-oxide diffusive gradients in thin films (Zr-oxide DGT) technique. The DGT-labile As, interpreted as DGT flux (FDGT), exhibited three different patterns in the lake, with all the patterns generally showing an increasing mobility followed by a decreasing mobility with sediment depth. The mobility of As could be characterized by the average FDGT (0.06-1.27 pg cm(-2) s(-1)) in the top 10 mm surface sediments, the maximal FDGT (FDGT-M, 0.14-2.44 pg cm(-2) s(-1)) in the end of the initial increasing phase of FDGT, and the diffusion length (ΔL, 28-66 mm) from the depth showing the FDGT-M to the sediment-water interface. The upward mobilization of labile As from the deep sediments to the surface sediments and overlying water became evident when FDGT-M > 1.7 pg cm(-2) s(-1) or ΔL mobility of As in the upper sediments was controlled by the reduction of As(V) and the reductive dissolution of Fe(III) (hydr)oxides, while the decreasing mobility in the deep sediments was attributed to immobilization of As(III) by secondary Fe(II)-bearing minerals.

  8. Spatio-Temporal Assessment and Water Quality Characteristics of Lake Tiga, Kano, Nigeria

    Directory of Open Access Journals (Sweden)

    E. O. Akindele

    2013-02-01

    Full Text Available The physico-chemical water quality of Lake Tiga was monitored over a two-year period (March 2009-March 2011 in order to bridge the information gap on its limnology and assess its physico-chemical condition. Turbidity, Dissolved Oxygen (DO saturation and organic matter were significantly higher (p<0.05 in the rainy season than in the dry season, while pH and Biological Oxygen Demand were significantly higher (p<0.05 in the dry season than in the rainy season. Apparent colour, Total Solids (TS, Total Suspended Solids (TSS, K+ Cl-, total acidity, total hardness, NO3- and PO43- decreased (p<0.05 from the riverine section towards the dam site, while water transparency, Dissolved Oxygen (DO, SO42 and Mg2+ showed an increase (p<0.05 from the riverine section towards the dam site. Apparent colour, TS, TSS, total acidity, total hardness, Ca2+ NO3- and PO43- increased (p<0.05 from the surface down to the bottom, while pH, Mg2+ and DO decreased (p<0.05 from the surface down to the bottom at the lacustrine section of the lake. Cluster analysis of the parameters showed major clusters between the major ions (Ca2+, Na+, K+, Cl-, HCO3- and the general chemical characteristics (TDS, alkalinity, conductivity, acidity and hardness and also between the nutrient compounds (Organic matter, NO3- and PO43- and the hydro-physical parameters (TS, TSS, apparent colour, true colour and turbidity. The water quality indices and sodium absorption ratio values in the sampled stations indicated that the water is most suitable for probable applications at the lacustrine section, towards the dam site.

  9. Ecotoxicological assessment of a recipient lake sediment of bleached-kraft pulping discharges

    Energy Technology Data Exchange (ETDEWEB)

    Suominen, K.P.; Wittmann, C.; Liukkonen, M.; Kaehkoenen, M.A.; Salkinoja-Salonen, M.S.

    1999-10-01

    The authors assessed the biological status of age-dated sediments in Lake Saimaa, a recipient lake for wastewaters from pulp and paper industry for more than 100 years that has also received kraft pulp bleaching wastewater since 1954. Adenosine triphosphate content dropped in the recipient sediment from the top 1 cm to 4 to 6 cm below the sediment surface by a factor of 1,000 but increased again in deeper, older layers. The dominant species in the diatom community, Aulacoseira alpigena and Cyclotella kuetzingiana, disappeared and were replaced by Asterionella formosa in the 4- to 6-cm layer. This layer was three- to fivefold more toxic to Vibrio fischeri (as measured by the median effective concentration) and slightly genotoxic (as measured by the SOS-chromotest induction ratio, I{sub c}/I{sub o} for Esherichia coli PQ37) compared with the layers above and below it. The 4- to 6-cm layer also contained up to 4,900 mg of solvent-soluble organic halogen. Enzyme activity was detected at depths of 0 to 1 cm and 4 to 6 cm, and more than 90% of the enzymes were bound to the particulate matter. Ninety-seven percent of the organic halogen in the sediment was particle bound. Apparently, full ecological recovery occurred in the layer from 0 to 1 cm, which had accumulated in 1990s, after the discharging pulp mill discontinued use of Cl{sub 2} in the bleaching process and installed full-scale biological treatment for the wastewaters.

  10. 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.

  11. Assessing the potential hydrological impact of the Gibe III Dam on Lake Turkana water level using multi-source satellite data

    Science.gov (United States)

    Velpuri, N. M.; Senay, G. B.

    2012-03-01

    commencement. Areas along the Lake Turkana shoreline that are vulnerable to fluctuations in lake levels were also identified. This study demonstrates the effectiveness of using existing multi-source satellite data in a basic modeling framework to assess the potential hydrological impact of an upstream dam on a terminal downstream lake. The results obtained from this study could also be used to evaluate alternate dam-filling scenarios and assess the potential impact of the dam on Lake Turkana under different operational strategies.

  12. Assessing the potential hydrological impact of the Gibe III Dam on Lake Turkana water level using multi-source satellite data

    Directory of Open Access Journals (Sweden)

    N. M. Velpuri

    2012-10-01

    dam commencement. Areas along the Lake Turkana shoreline that are vulnerable to fluctuations in lake levels due to the Gibe III dam were also identified. This study demonstrates the effectiveness of using existing multi-source satellite data in a basic modeling framework to assess the potential hydrological impact of an upstream dam on a terminal downstream lake. The results obtained from this study could also be used to evaluate alternative dam-filling scenarios and assess the potential impact of the dam on Lake Turkana under different operational strategies.

  13. Assessing the potential hydrological impact of the Gibe III Dam on Lake Turkana water level using multi-source satellite data

    Directory of Open Access Journals (Sweden)

    N. M. Velpuri

    2012-03-01

    at the time of dam commencement. Areas along the Lake Turkana shoreline that are vulnerable to fluctuations in lake levels were also identified. This study demonstrates the effectiveness of using existing multi-source satellite data in a basic modeling framework to assess the potential hydrological impact of an upstream dam on a terminal downstream lake. The results obtained from this study could also be used to evaluate alternate dam-filling scenarios and assess the potential impact of the dam on Lake Turkana under different operational strategies.

  14. Assessment of multiple sources of anthropogenic and natural chemical inputs to a morphologically complex basin, Lake Mead, USA

    Science.gov (United States)

    Rosen, Michael R.; Van Metre, P.C.

    2010-01-01

    Lakes with complex morphologies and with different geologic and land-use characteristics in their sub-watersheds could have large differences in natural and anthropogenic chemical inputs to sub-basins in the lake. Lake Mead in southern Nevada and northern Arizona, USA, is one such lake. To assess variations in chemical histories from 1935 to 1998 for major sub-basins of Lake Mead, four sediment cores were taken from three different parts of the reservoir (two from Las Vegas Bay and one from the Overton Arm and Virgin Basin) and analyzed for major and trace elements, radionuclides, and organic compounds. As expected, anthropogenic contaminant inputs are greatest to Las Vegas Bay reflecting inputs from the Las Vegas urban area, although concentrations are low compared to sediment quality guidelines and to other USA lakes. One exception to this pattern was higher Hg in the Virgin Basin core. The Virgin Basin core is located in the main body of the lake (Colorado River channel) and is influenced by the hydrology of the Colorado River, which changed greatly with completion of Glen Canyon Dam upstream in 1963. Major and trace elements in the core show pronounced shifts in the early 1960s and, in many cases, gradually return to concentrations more typical of pre-1960s by the 1980s and 1990s, after the filling of Lake Powell. The Overton Arm is the sub-basin least effected by anthropogenic contaminant inputs but has a complex 137Cs profile with a series of large peaks and valleys over the middle of the core, possibly reflecting fallout from nuclear tests in the 1950s at the Nevada Test Site. The 137Cs profile suggests a much greater sedimentation rate during testing which we hypothesize results from greatly increased dust fall on the lake and Virgin and Muddy River watersheds. The severe drought in the southwestern USA during the 1950s might also have played a role in variations in sedimentation rate in all of the cores. ?? 2009.

  15. Transforming Ontario's Power Generation Company

    International Nuclear Information System (INIS)

    The OPG Review Committee was formed by the Ontario Ministry of Energy to provide recommendations and advice on the future role of Ontario Power Generation Inc. (OPG) in the electricity sector. This report describes the future structure of OPG with reference to the appropriate corporate governance and senior management structure. It also discusses the potential refurbishing of the Pickering A nuclear generating Units 1, 2 and 3. The electricity system in Ontario is becoming increasingly fragile. The province relies heavily on electricity imports and the transmission system is being pushed to near capacity. Three nuclear generating units are out of service. The problems can be attributed to the fact that the electricity sector has been subjected to unpredictable policy changes for more than a decade, and that the largest electricity generator (OPG) has not been well governed. OPG has had frequent senior management change, accountability has been weak, and cost overruns have delayed the return to service of the Pickering nuclear power Unit 4. It was noted that the generating assets owned and operated by OPG are capable of providing more than 70 per cent of Ontario's electricity supply. Decisive action is needed now to avoid a potential supply shortage of about 5,000 to 7,000 megawatts by 2007. In its current state, OPG risks becoming a burden on ratepayers. Forty recommendations were presented, some of which suggest that OPG should become a rate-regulated commercial utility focused on running and maintaining its core generating assets. This would require that the government act as a shareholder, and the company operate like a commercial business. It was also emphasized that the market must be allowed to bring in new players. refs., tabs., figs

  16. "Uberizing" home care in Ontario.

    Science.gov (United States)

    Wojtak, Anne; Stark, Linda

    2016-07-01

    This article looks at home care in Ontario and its role as a foundation for a sustainable healthcare system in the future. Beginning with the history and evolution of the service delivery model, it examines current challenges and opportunities to unleash the potential of home care within a more integrated model for patient-centred care for the future. An in-depth look at how to better coordinate, integrate, and fund care for patients is highlighted. PMID:27269814

  17. Distribution, source identification and risk assessment of selected metals in sediments from freshwater lake

    Institute of Scientific and Technical Information of China (English)

    Javed Iqbal; Munir H. Shah; Nazia Shaheen

    2015-01-01

    abstract This study is based on the assessment of distribution, source apportionment and risk assessment of selected metals in freshly deposited sediments from freshwater lake, Pakistan. Composite sediments were collected and processed to assess Ca(NO3)2-extractable and acid-extractable levels of the metals in the sediments using flame atomic absorption spectrophotometry. Enrichment factors (EF), geoaccumu-lation indices (Igeo), contamination factors (Cf) and degree of contamination (Cdeg) were computed to estimate the degree of contamination. The potential ecological risk was assessed using sediment quality guidelines and mean-ERM-quotient (m-ERM-Q). On the average basis, acid-extractable metals followed the decreasing concentration order: Ca>Mg>Fe>K>Mn>Na>Sr>Zn>Pb>Cr>Co>Cu>-Li>Cd, whereas, the Ca(NO3)2-extractable levels were: Na>Pb>Cd>Sr>Co>Cr>K>Mg>-Cu>Zn>Li>Ca>Fe>Mn. The highest Ca(NO3)2 extractable concentrations were observed for Na, Pb and Cd, while that of Ca, Fe and Mn were the least. EF showed very high and extremely high enrichment of Pb and Cd, respectively, while Ca, Co, Cr, Li, Mg, Mn, Sr and Zn manifested moderate enrichment;the Igeo results revealed moderate to strong and strong to extreme pollution for Pb and Cd, respectively; and the Cf study showed moderate, considerable and very high contamination by Co, Pb and Cd, respectively. The Cdeg revealed very high degree of contamination in the sediments as a whole. Principal component analysis (PCA) and cluster analysis (CA) showed considerable anthropogenic contributions of Cd, Pb, Co, Mn, K, Zn and Li in the sediments. Measured levels of Cd and Pb exceeded ERL values, manifesting occasional adverse biological effects to the dwelling biota. Moreover, the m-ERM-Q study manifested 21%probability of toxicity in the sediments.

  18. The safety of Ontario's nuclear reactors

    International Nuclear Information System (INIS)

    A Select Committee of the Legislature of Ontario was established to examine the affairs of Ontario Hydro, the provincial electrical utility. Extensive public hearings were held on several topics including the safety of nuclear power reactors operating in Ontario. The Committee found that these reactors are acceptably safe. Many of the 24 recommendations in this report deal with the licensing process and public access to information. (O.T.)

  19. Lake Victoria: the Changing Lake.

    OpenAIRE

    Mwirigi, P.; Rutagemwa, D.; Gikuma-Njuru, P.; Njuguna, H.; Matovu, A.; Waya, R.; Mwebaza-Ndawula, L.; Ssenfuma-Nsubuga, M.; Kinobe, J.; Abuodha, J.; Hecky, R

    2005-01-01

    Water quality monitoring activities were carried out on physical-chemical parameters, water chemistry and biotic indices at selected littoral and pelagic stations along north-south and east-west transects over an annual cycle between 2000 and 2005. The activities were aimed at collecting baseline information and data for use to define the current lake conditions and make a water quality assessment of the lake in relation to nutrient/ pollutant loadings as a basis for future monitoring surveys...

  20. The restructuring of the Ontario electricity market

    International Nuclear Information System (INIS)

    A summary of the current status of the deregulation of the electricity market in Ontario was presented. To follow global deregulation trends, the Ontario Government has embarked on a considerable restructuring of the Ontario electricity market. The monopoly position of Ontario Hydro has been removed by restructuring the provincial utility into two separate companies, GENCO and SERVCO, which will be responsible for the generation and transmission and distribution of electricity, respectively. Other mechanisms put in place to favour a free and competitive market for electricity in the province, such as the arrival on the market of other electricity producers, and the establishment of the independent market operator, are also discussed. 2 tabs

  1. Alternative models for restructuring Ontario's electric sector

    International Nuclear Information System (INIS)

    The future of Ontario Hydro and the provincial electrical sector was discussed. Various models proposed for restructuring Ontario's electric sector were described and views of some of the stake holders were presented, among them the views of AMPCO, MEA, the Ontario Chamber of Commerce, IPPSO, Ontario Hydro Management, Energy Probe and the Power Workers' Union. In general, most stake holders were in favour of privatization to some degree except for the Power Workers' Union which was unalterably opposed to privatization, claiming that it would lead to quantum increases in electricity rates. 2 figs

  2. The Education Act (Ontario) 1980: A Review.

    Science.gov (United States)

    Hodder, C. J.

    1984-01-01

    Ontario has provided special education legislation through the Education Amendment Act, 1980. Issues related to teacher preparation for special education and program planning and implementation are reviewed. (DF)

  3. [Ontario Hydro]. Corporate performance report, 1993

    International Nuclear Information System (INIS)

    Summarizes Ontario Hydro's corporate performance for the year, with actual results being compared against planned values established in the approved corporate financial plan and work program budget. Also includes additional indicators that illustrate noteworthy trends in corporate performance. Corporate results are reported under the new organizational structure implemented in mid-1993, beginning with overall results in such areas as customer satisfaction, electricity sales, human resources, and environmental protection. This is followed by reports from the Electricity Group (supply, generation, transmission), the Energy Services and Environment Group (load saved and shifted, non-utility generation, retail distribution), and Ontario Hydro enterprises (Ontario Hydro Technologies, Ontario Hydro International). The appendix contains summary financial statements

  4. Acidification and recovery at mountain lakes in Central Alps assessed by the MAGIC model

    Directory of Open Access Journals (Sweden)

    Michela ROGORA

    2004-02-01

    Full Text Available The dynamic model MAGIC was calibrated and applied to 84 lakes in Central Alps to predict the response of water chemistry to different scenarios of atmospheric deposition of S and N compounds. Selected lakes were representative of a wide range of chemical characteristics and of sensitivity to acidification. The most sensitive lakes have already shown in the latest years signs of recovery in terms of pH and ANC. The model well captured the main trends in lake chemical data. According to the model forecast, recovery at sensitive lakes will continue in the next decades under the hypothesis of a further decrease of acidic input from the atmosphere. Results clearly demonstrated the benefits of achieving the emission reductions in both S and N compounds agreed under the Gothenburg Protocol. Nevertheless, besides the achieved reduction of SO4 2- deposition from the peak levels of the 80s, also N deposition should be reduced in the near future to protect alpine lakes from further acidification. The condition of lake catchments with regard to N saturation will probably be the dominant factor driving recovery extent. Beside atmospheric deposition, other factors proved to be important in determining long-term changes in surface water chemistry. Climate warming in particular affects weathering processes in lake catchments and dynamics of the N cycle. Including other factors specific to the alpine area, such as dust deposition and climate change, may improve the fit of experimental data by the model and the reliability of model forecast.

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

    International Nuclear Information System (INIS)

    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 U3O8 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

  6. Preliminary Assessment of Cyanobacteria Diversity and Toxic Potential in Ten Freshwater Lakes in Selangor, Malaysia.

    Science.gov (United States)

    Sinang, Som Cit; Poh, Keong Bun; Shamsudin, Syakirah; Sinden, Ann

    2015-10-01

    Toxic cyanobacteria blooms are increasing in magnitude and frequency worldwide. However, this issue has not been adequately addressed in Malaysia. Therefore, this study aims to better understand eutrophication levels, cyanobacteria diversity, and microcystin concentrations in ten Malaysian freshwater lakes. The results revealed that most lakes were eutrophic, with total phosphorus and total chlorophyll-a concentrations ranging from 15 to 4270 µg L(-1) and 1.1 to 903.1 µg L(-1), respectively. Cyanobacteria were detected in all lakes, and identified as Microcystis spp., Planktothrix spp., Phormidium spp., Oscillatoria spp., and Lyngbya spp. Microcystis spp. was the most commonly observed and most abundant cyanobacteria recorded. Semi-quantitative microcystin analysis indicated the presence of microcystin in all lakes. These findings illustrate the potential health risk of cyanobacteria in Malaysia freshwater lakes, thus magnifying the importance of cyanobacteria monitoring and management in Malaysian waterways.

  7. Assessing Resiliency in a Large Lake Receiving Mine Tailings Waste: Impacts of Major Environmental Disturbance.

    Science.gov (United States)

    Petticrew, Ellen; Owens, Philip; Albers, Sam

    2016-04-01

    On 4th August 2014, the tailings impoundment of the Mount Polley copper and gold mine in British Columbia failed. Material from the impoundment (surface area = 2.7 km2) flowed into nearby Polley Lake and Hazeltine Creek, before discharging into Quesnel Lake, a large (ca. 100 km long, >500 m deep), relatively pristine lake. Initial estimates suggest that approximately 25 Mm3 of tailings (water and solids) and eroded soils and surficial materials from Hazeltine Creek were delivered to Quesnel Lake, raising the lake by 7.7 cm. Much of this material was deposited at the bottom of Quesnel Lake but a plume of fine-grained sediment (D50 of ca. 1 μm) remained suspended in the water column. The impact of the distribution of this sediment was monitored over the next 15 months using water column profiling for temperature, conductivity, fluorescence and turbidity with depth. The plume movement was regulated by natural processes associated with the physical limnology of this large fjord lake, specifically, seiche events which transferred suspended particles both up-lake, against the flow regime, and down-lake into the Quesnel River. Samples of lake water and bottom sediment taken from the impacted area show elevated levels of total metals and other elements, which may have important ecosystem implications in this watershed. Indeed, the breach occurred at a time when a peak run of sockeye salmon were returning to their natal streams in the Quesnel basin. Zooplankton sampling for metals was initiated in fall 2014 to determine up take of metals into the food web. This poster describes the failure of the impoundment dam and presents results of sampling the aquatic environment over the first fifteen months of impact.

  8. Pharmaceuticals, hormones and bisphenol A in untreated source and finished drinking water in Ontario, Canada - Occurrence and treatment efficiency

    International Nuclear Information System (INIS)

    The Ontario Ministry of the Environment (MOE) conducted a survey in 2006 on emerging organic contaminants (EOCs) which included pharmaceuticals, hormones and bisphenol A (BPA). The survey collected 258 samples over a 16 month period from selected source waters and 17 drinking water systems (DWSs), and analyzed them for 48 EOCs using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and isotope dilution mass spectrometry (IDMS) for the highest precision and accuracy of analytical data possible. 27 of the 48 target EOCs were detected in source water, finished drinking water, or both. DWSs using river and lake source water accounted for > 90% detections. Of the 27 EOCs found, we also reported the first detection of two antibiotics roxithromycin and enrofloxacin in environmental samples. The most frequently detected compounds (≥ 10%) in finished drinking water were carbamazepine (CBZ), gemfibrozil (GFB), ibuprofen (IBU), and BPA; with their concentrations accurately determined by using IDMS and calculated to be 4 to 10 times lower than those measured in the source water. Comparison of plant specific data allowed us to determine removal efficiency (RE) of these four most frequently detected compounds in Ontario DWSs. The RE of CBZ was determined to be from 71 to 93% for DWSs using granulated activated carbon (GAC); and was 75% for DWSs using GAC followed by ultraviolet irradiation (UV). The observed RE of GFB was between 44 and 55% in DWSs using GAC and increased to 82% when GAC was followed by UV. The use of GAC or GAC followed by UV provided an RE improvement of BPA from 80 to 99%. These detected concentration levels are well below the predicted no effect concentration or total allowable concentration reported in the literature. Additional targeted, site specific comparative research is required to fully assess the effectiveness of Ontario DWSs to remove particular compounds of concern. - Research Highlights: → Occurrence and typical range of 45 selected

  9. Pharmaceuticals, hormones and bisphenol A in untreated source and finished drinking water in Ontario, Canada - Occurrence and treatment efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Kleywegt, Sonya; Pileggi, Vince [Standards Development Branch, Ontario Ministry of the Environment, 40 St. Clair Avenue West, Toronto, Ontario, M4V 1M2 (Canada); Yang, Paul, E-mail: paul.yang@ontario.ca [Laboratory Services Branch, Ontario Ministry of the Environment, 125 Resources Road, Etobicoke, Ontario, M9P 3V6 (Canada); Hao Chunyan; Zhao Xiaoming [Laboratory Services Branch, Ontario Ministry of the Environment, 125 Resources Road, Etobicoke, Ontario, M9P 3V6 (Canada); Rocks, Carline [Environmental Monitoring and Reporting Branch, Ontario Ministry of the Environment, 125 Resources Road, Etobicoke, Ontario, M9P 3V6 (Canada); Thach, Serei [Laboratory Services Branch, Ontario Ministry of the Environment, 125 Resources Road, Etobicoke, Ontario, M9P 3V6 (Canada); Cheung, Patrick; Whitehead, Brian [Environmental Monitoring and Reporting Branch, Ontario Ministry of the Environment, 125 Resources Road, Etobicoke, Ontario, M9P 3V6 (Canada)

    2011-03-15

    The Ontario Ministry of the Environment (MOE) conducted a survey in 2006 on emerging organic contaminants (EOCs) which included pharmaceuticals, hormones and bisphenol A (BPA). The survey collected 258 samples over a 16 month period from selected source waters and 17 drinking water systems (DWSs), and analyzed them for 48 EOCs using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and isotope dilution mass spectrometry (IDMS) for the highest precision and accuracy of analytical data possible. 27 of the 48 target EOCs were detected in source water, finished drinking water, or both. DWSs using river and lake source water accounted for > 90% detections. Of the 27 EOCs found, we also reported the first detection of two antibiotics roxithromycin and enrofloxacin in environmental samples. The most frequently detected compounds ({>=} 10%) in finished drinking water were carbamazepine (CBZ), gemfibrozil (GFB), ibuprofen (IBU), and BPA; with their concentrations accurately determined by using IDMS and calculated to be 4 to 10 times lower than those measured in the source water. Comparison of plant specific data allowed us to determine removal efficiency (RE) of these four most frequently detected compounds in Ontario DWSs. The RE of CBZ was determined to be from 71 to 93% for DWSs using granulated activated carbon (GAC); and was 75% for DWSs using GAC followed by ultraviolet irradiation (UV). The observed RE of GFB was between 44 and 55% in DWSs using GAC and increased to 82% when GAC was followed by UV. The use of GAC or GAC followed by UV provided an RE improvement of BPA from 80 to 99%. These detected concentration levels are well below the predicted no effect concentration or total allowable concentration reported in the literature. Additional targeted, site specific comparative research is required to fully assess the effectiveness of Ontario DWSs to remove particular compounds of concern. - Research Highlights: {yields} Occurrence and typical range of 45

  10. CHANGES IN GENETIC DIVERSITY OF A WHITE SUCKER POPULATION FOLLOWING EXPERIMENTAL WHOLE-LAKE ACIDIFICATION

    Science.gov (United States)

    Despite great strides to reduce sulfur dioxide emissions over the last decade, acid precipitation remains a persistent threat to North American fish communities. A demographic analysis of white suckers in an experimentally acidified oligotrophic lake in northwest Ontario demonst...

  11. Spatially explicit exposure assessment for small streams in catchments of the orchard growing region `Lake Constance

    Science.gov (United States)

    Golla, B.; Bach, M.; Krumpe, J.

    2009-04-01

    1. Introduction Small streams differ greatly from the standardised water body used in the context of aquatic risk assessment for the regulation of plant protection products in Germany. The standard water body is static, with a depth of 0.3 m and a width of 1.0 m. No dilution or water replacement takes place. Spray drift happens always in direction to the water body. There is no variability in drift deposition rate (90th percentile spray drift deposition values [2]). There is no spray drift filtering by vegetation. The application takes place directly adjacent to the water body. In order to establish a more realistic risk assessment procedure the Federal Office for Consumer Protection and Food Safety (BVL) and the Federal Environment Agency (UBA) aggreed to replace deterministic assumptions with data distributions and spatially explicit data and introduce probabilistic methods [3, 4, 5]. To consider the spatial and temporal variability in the exposure situations of small streams the hydraulic and morphological characteristics of catchments need to be described as well as the spatial distribution of fields treated with pesticides. As small streams are the dominant type of water body in most German orchard regions, we use the growing region Lake Constance as pilot region. 2. Materials and methods During field surveys we derive basic morphological parameters for small streams in the Lake Constance region. The mean water width/depth ratio is 13 with a mean depth of 0.12 m. The average residence time is 5.6 s/m (n=87) [1]. Orchards are mostly located in the upper parts of the catchments. Based on an authoritative dataset on rivers and streams of Germany (ATKIS DLM25) we constructed a directed network topology for the Lake Constance region. The gradient of the riverbed is calculated for river stretches of > 500 m length. The network for the pilot region consists of 2000 km rivers and streams. 500 km stream length are located within a distance of 150 m to orchards. Within

  12. Concentrations and human health risk assessment of organochlorine pesticides in edible fish species from a Rift Valley lake-Lake Ziway, Ethiopia.

    Science.gov (United States)

    Yohannes, Yared B; Ikenaka, Yoshinori; Saengtienchai, Aksorn; Watanabe, Kensuke P; Nakayama, Shouta M M; Ishizuka, Mayumi

    2014-08-01

    Fish consumption is known to have several health benefits for humans. However, the accumulation of organic pollutants, like organochlorine pesticides (OCPs) could pose health hazards. Thus, OCPs in edible fish species (Oreochromis niloticus, Tilapia zillii, Carassius spp., and Clarias gariepinus) from Lake Ziway, an Ethiopian Rift Valley Lake were investigated to assess the potential human health hazards of these contaminants. Dichlorodiphenyltrichloroethanes (DDTs), hexachlorocyclohexanes (HCHs), chlordanes, and heptachlors were observed with ΣOCPs concentration ranging from 1.41 to 63.8 ng g(-1) ww. DDTs were the predominant contaminants (0.9 to 61.9 ng g(-1) ww), followed by HCHs. The predominance of DDTs may be attributed to their current use in vector control and contamination from past usage. The estimated daily intakes (EDIs) of OCPs from all fish species were much lower than the acceptable daily intakes (ADIs), indicating that consumption of fish is at little risk to human health at present. However, the cancer risk estimates in the area of concern and the hazard ratios (HRs) of HCHs, DDTs, and heptachlors exceeded the threshold value of one, indicating daily exposure to these compounds is a potential concern. This may result in a lifetime cancer risk greater than of 1 in 10(6). PMID:24836883

  13. Cyanotoxins in inland lakes of the United States: Occurrence and potential recreational health risks in the EPA National Lakes Assessment 2007

    Science.gov (United States)

    Loftin, Keith A.; Graham, Jennifer; Elizabeth Hilborn,; Sarah Lehmann,; Meyer, Michael T.; Dietze, Julie E.; Griffith, Christopher

    2016-01-01

    A large nation-wide survey of cyanotoxins (1161 lakes) in the United States (U.S.) was conducted during the EPA National Lakes Assessment 2007. Cyanotoxin data were compared with cyanobacteria abundance- and chlorophyll-based World Health Organization (WHO) thresholds and mouse toxicity data to evaluate potential recreational risks. Cylindrospermopsins, microcystins, and saxitoxins were detected (ELISA) in 4.0, 32, and 7.7% of samples with mean concentrations of 0.56, 3.0, and 0.061 mg/L, respectively (detections only). Co-occurrence of the three cyanotoxin classes was rare (0.32%) when at least one toxin was detected. Cyanobacteria were present and dominant in 98 and 76% of samples, respectively. Potential anatoxin-, cylindrospermopsin-, microcystin-, and saxitoxin-producing cyanobacteria occurred in 81, 67, 95, and 79% of samples, respectively. Anatoxin-a and nodularin-R were detected (LC/MS/MS) in 15 and 3.7% samples (n = 27). The WHO moderate and high risk thresholds for microcystins, cyanobacteria abundance, and total chlorophyll were exceeded in 1.1, 27, and 44% of samples, respectively. Complete agreement by all three WHO microcystin metrics occurred in 27% of samples. This suggests that WHO microcystin metrics based on total chlorophyll and cyanobacterial abundance can overestimate microcystin risk when compared to WHO microcystin thresholds. The lack of parity among the WHO thresholds was expected since chlorophyll is common amongst all phytoplankton and not all cyanobacteria produce microcystins.

  14. Distribution of polycyclic aromatic hydrocarbon (PAH) residues in several tissues of edible fishes from the largest freshwater lake in China, Poyang Lake, and associated human health risk assessment.

    Science.gov (United States)

    Zhao, Zhonghua; Zhang, Lu; Cai, Yongjiu; Chen, Yuwei

    2014-06-01

    The residual levels, tissue distribution and human health risk assessment of polycyclic aromatic hydrocarbons (PAHs) in edible fishes, bighead carp (Aristichthys nobilis) and silver carp (Hypophthalmichthys molitrix), from the largest freshwater lake in China, Poyang Lake, were studied. PAH concentrations ranged from 105 to 513ng g(-1)ww and from 53.9 to 401ng g(-1)ww in different tissues of bighead carp and silver carp, respectively. Low molecular weight (LMW) PAHs were the predominant compounds, suggesting the gill-water transfer might be the major exposure route for PAHs in the studied fish species. Tissue distribution indicated that the hepatobiliary system accumulated higher concentrations of PAHs than the extrahepatic tissues with bile being the most predominant tissue for both species. Composition analysis demonstrated that PAHs were from the combined petrogenic and pyrogenic origin, and the gasoline combustion might be the main source. A preliminary evaluation of human health risk using benzo[a]pyrene (BaP) potency equivalent concentration (PEC) as well as the incremental lifetime cancer risk (ILCR) indicated that PAHs in fish would induce potential carcinogenic effects. PMID:24732028

  15. Assessing Ecotourism from a Multi-stakeholder Perspective: Xingkai Lake National Nature Reserve, China

    Science.gov (United States)

    Su, Ming Ming; Wall, Geoffrey; Ma, Zhong

    2014-11-01

    Ecotourism development is closely associated with the sustainability of protected natural areas. When facilitated by appropriate management, ecotourism can contribute to conservation and development, as well as the well-being of local communities. As such, ecotourism has been proposed and practiced in different forms in many places, including China. This study assesses ecotourism development at Xingkai Lake National Nature Reserve in Heilongjiang Province, China. Key informant interviews were conducted with representatives from the provincial Forestry Department, the Nature Reserve, and the local community. Observation was undertaken on three site visits and secondary data were collected. The potential for providing quality natural experiences is high and tourism development is occurring rapidly. However, current relationships between people, resources, and tourism have yet to provide mutual benefits necessary for successful ecotourism. The multi-stakeholder management style and the ambiguity of landownership within the nature reserve constitute structural difficulties for ecotourism management and operation. Although participation in ecotourism could provide a livelihood opportunity and interests in involvement in tourism have been identified among the local fishing community, current involvement is limited mainly due to the lack of mechanisms for participation. Therefore, it is recommended that management programs and government policies should be established to provide a platform for community participation in ecotourism. Then, a positive synergistic relationship between tourism, environment, and community could be developed. Planning and policy requirements are discussed for ecotourism development in protected areas in China.

  16. Mapping landslide processes in the North Tanganyika - Lake Kivu rift zones: towards a regional hazard assessment

    Science.gov (United States)

    Dewitte, Olivier; Monsieurs, Elise; Jacobs, Liesbet; Basimike, Joseph; Delvaux, Damien; Draida, Salah; Hamenyimana, Jean-Baptiste; Havenith, Hans-Balder; Kubwimana, Désiré; Maki Mateso, Jean-Claude; Michellier, Caroline; Nahimana, Louis; Ndayisenga, Aloys; Ngenzebuhoro, Pierre-Claver; Nkurunziza, Pascal; Nshokano, Jean-Robert; Sindayihebura, Bernard; Philippe, Trefois; Turimumahoro, Denis; Kervyn, François

    2015-04-01

    The mountainous environments of the North Tanganyika - Lake Kivu rift zones are part of the West branch of the East African Rift. In this area, natural triggering and environmental factors such as heavy rainfalls, earthquake occurrences and steep topographies favour the concentration of mass movement processes. In addition anthropogenic factors such as rapid land use changes and urban expansion increase the sensibility to slope instability. Until very recently few landslide data was available for the area. Now, through the initiation of several research projects and the setting-up of a methodology for data collection adapted to this data-poor environment, it becomes possible to draw a first regional picture of the landslide hazard. Landslides include a wide range of ground movements such as rock falls, deep failure of slopes and shallow debris flows. Landslides are possibly the most important geohazard in the region in terms of recurring impact on the populations, causing fatalities every year. Many landslides are observed each year in the whole region, and their occurrence is clearly linked to complex topographic, lithological and vegetation signatures coupled with heavy rainfall events, which is the main triggering factor. Here we present the current knowledge of the various slope processes present in these equatorial environments. A particular attention is given to urban areas such as Bukavu and Bujumbura where landslide threat is particularly acute. Results and research perspectives on landslide inventorying, monitoring, and susceptibility and hazard assessment are presented.

  17. Assessing ecotourism from a multi-stakeholder perspective: Xingkai Lake National Nature Reserve, China.

    Science.gov (United States)

    Su, Ming Ming; Wall, Geoffrey; Ma, Zhong

    2014-11-01

    Ecotourism development is closely associated with the sustainability of protected natural areas. When facilitated by appropriate management, ecotourism can contribute to conservation and development, as well as the well-being of local communities. As such, ecotourism has been proposed and practiced in different forms in many places, including China. This study assesses ecotourism development at Xingkai Lake National Nature Reserve in Heilongjiang Province, China. Key informant interviews were conducted with representatives from the provincial Forestry Department, the Nature Reserve, and the local community. Observation was undertaken on three site visits and secondary data were collected. The potential for providing quality natural experiences is high and tourism development is occurring rapidly. However, current relationships between people, resources, and tourism have yet to provide mutual benefits necessary for successful ecotourism. The multi-stakeholder management style and the ambiguity of landownership within the nature reserve constitute structural difficulties for ecotourism management and operation. Although participation in ecotourism could provide a livelihood opportunity and interests in involvement in tourism have been identified among the local fishing community, current involvement is limited mainly due to the lack of mechanisms for participation. Therefore, it is recommended that management programs and government policies should be established to provide a platform for community participation in ecotourism. Then, a positive synergistic relationship between tourism, environment, and community could be developed. Planning and policy requirements are discussed for ecotourism development in protected areas in China.

  18. Evaluation of Multi-Resolution Satellite Sensors for Assessing Water Quality and Bottom Depth of Lake Garda

    OpenAIRE

    Claudia Giardino; Mariano Bresciani; Ilaria Cazzaniga; Karin Schenk; Patrizia Rieger; Federica Braga; Erica Matta; Vittorio E. Brando

    2014-01-01

    In this study we evaluate the capabilities of three satellite sensors for assessing water composition and bottom depth in Lake Garda, Italy. A consistent physics-based processing chain was applied to Moderate Resolution Imaging Spectroradiometer (MODIS), Landsat-8 Operational Land Imager (OLI) and RapidEye. Images gathered on 10 June 2014 were corrected for the atmospheric effects with the 6SV code. The computed remote sensing reflectance (Rrs ) from MODIS and OLI were converted into water qu...

  19. Erratum - Assessing the effects of climate and volcanism on diatom and chironomid assemblages in an Andean lake near Quito, Ecuador

    Directory of Open Access Journals (Sweden)

    Neal Michelutti

    2016-02-01

    Full Text Available This corrects the article entitled “Assessing the effects of climate and volcanism on diatom and chironomid assemblages in an Andean lake near Quito, Ecuador” by the authors Neal Michelutti, Jillian L. Lemmen, Colin A. Cooke, William O. Hobbs, Alexander P. Wolfe, Joshua Kurek, John P. Smol, published with DOI 10.4081/jlimnol.2015.1323. The map in Fig. 1 was incorrectly labelled and the correct version of Fig. 1 is presented below.

  20. Preliminary assessment of heavy metal contamination in surface water and sediments from Honghu Lake,East Central China

    Institute of Scientific and Technical Information of China (English)

    Ying HU; Shihua QI; Chenxi WU; Yanping KE; Jing CHEN; Wei CHEN; Xiangyi GONG

    2012-01-01

    Heavy metal concentrations in surface water and sediments collected from Honghu Lake in Hubei Province,China were analyzed,and ecological risks were evaluated according to the sediment quality guidelines.The results showed that the average concentrations of heavy metals in surface water were ranked as:As > Zn >Cu > Cr > Pb > Ni > Cd > Hg.In comparison with results reported in other rivers and the background values,The Honghu Lake was polluted by As,Cr,Pb,Cu and Ni.Most of metals might be mainly from fertilizers,industrial effluent and domestic wastewater around the lake.Heavy metals concentrations were relatively higher in the inlet area than in other areas.Negative correlations were observed between most heavy metals and pH,while a significant positive correlation was present between Zn,Cd and Pb.In the sediment core,Cu,Zn,Cr and Ni showed a decreasing trend while Cd present an increasing trend.The decrease of As,Cu,Zn,Cr and Ni in the 1990s might due to the flood event in 1998.The analysis of ecological risk assessment based on sediment quality guidelines suggested that heavy metals in most sediments from the Honghu Lake had moderate toxicity,with Cr being the highest priority pollutant.

  1. Preliminary assessment of heavy metal contamination in surface water and sediments from Honghu Lake, East Central China

    Science.gov (United States)

    Hu, Ying; Qi, Shihua; Wu, Chenxi; Ke, Yanping; Chen, Jing; Chen, Wei; Gong, Xiangyi

    2012-03-01

    Heavy metal concentrations in surface water and sediments collected from Honghu Lake in Hubei Province, China were analyzed, and ecological risks were evaluated according to the sediment quality guidelines. The results showed that the average concentrations of heavy metals in surface water were ranked as: As>Zn> Cu>Cr>Pb>Ni>Cd>Hg. In comparison with results reported in other rivers and the background values, The Honghu Lake was polluted by As, Cr, Pb, Cu and Ni. Most of metals might be mainly from fertilizers, industrial effluent and domestic wastewater around the lake. Heavy metals concentrations were relatively higher in the inlet area than in other areas. Negative correlations were observed between most heavy metals and pH, while a significant positive correlation was present between Zn, Cd and Pb. In the sediment core, Cu, Zn, Cr and Ni showed a decreasing trend while Cd present an increasing trend. The decrease of As, Cu, Zn, Cr and Ni in the 1990s might due to the flood event in 1998. The analysis of ecological risk assessment based on sediment quality guidelines suggested that heavy metals in most sediments from the Honghu Lake had moderate toxicity, with Cr being the highest priority pollutant.

  2. Palaeolimnological assessment of the reference conditions and ecological status of lakes in Estonia - implications for the European Union Water Framework Directive

    Directory of Open Access Journals (Sweden)

    Heinsalu, Atko

    2009-12-01

    Full Text Available The European Union Water Framework Directive (WFD requires an assessment of reference conditions for lakes, i.e. the conditions expected with only minimal human impact on water bodies. Limnological monitoring records seldom go back more than a few decades and so rarely document the onset of human impact on lakes. Methods of palaeolimnological approaches especially fitted for the purposes of the WFD are described and two case studies, on lakes Rõuge Tõugjärv and Pappjärv, are presented. The palaeolimnological study of Rõuge Tõugjärv demonstrated that a commonly held belief that man-made eutrophication of Estonian lakes is a relatively modern matter of concern and is related to post-industrial population growth and intensification of agriculture is a misconception. The lakes, particularly those in rich soil areas, have been mediated by human impact over millennial time-scales. In many European countries it has been agreed that AD 1850 approximately represents the reference conditions for lakes. Our observations in Rõuge Tõugjärv showed that during that period anthropogenic disturbance on the lake was the greatest. Lake Pappjärv is an example of recent human influence on the aquatic ecosystem that has undergone severe degradation due to infiltration into the ground of a variety of substances from the local bitumen plant, mineral fertilizer storage tanks, and road service sand and salt mixing-grounds that have been accumulating in the lake since the 1950s.

  3. Sinkhole risk assessment by ERT: The case study of Sirino Lake (Basilicata, Italy)

    Science.gov (United States)

    Giampaolo, V.; Capozzoli, L.; Grimaldi, S.; Rizzo, E.

    2016-01-01

    The presence of natural or artificial lakes and reservoirs that can drain because of natural phenomena can generate catastrophic events affecting urban and agricultural areas next to the source area. Therefore, geophysical prospecting techniques have been applied in the study of Sirino Lake, which, during the last century, was affected by the sudden opening of small sinkholes, resulting in the almost total draining of the lake and in the sudden increase of water flow rates of distal springs. Two electrical resistivity tomographies (ERTs) were carried out across the lake, using electrode arrays located on land and across the water body. Self-potential (SP) data were acquired around the lake shore and the surrounding area. The geophysical prospecting contributed significant data toward explaining the unique hydrogeological characteristics of the lake. Integration of geophysical, geological, hydrogeological, and geomorphological data allowed us to estimate the thickness of the lacustrine deposits beneath the lake, to describe the main patterns of the subsurface fluid flows in the area, and to identify possible water escape routes causing the piping phenomena.

  4. Assessing downstream flood impacts due to a potential GLOF from Imja Lake in Nepal

    Directory of Open Access Journals (Sweden)

    M. A. Somos-Valenzuela

    2014-11-01

    Full Text Available Glacial-dominated areas pose unique challenges to downstream communities in adapting to recent and continuing global climate change, including increased threats of glacial lake outburst floods (GLOFs that can increase risk due to flooding of downstream communities and cause substantial impacts on regional social, environmental and economic systems. The Imja glacial lake in Nepal, with potential to generate a GLOF, was studied using a two-dimensional debris flow inundation model in order to evaluate the effectiveness of proposed measures to reduce possible flooding impacts to downstream communities by lowering the lake level. The results indicate that only minor flood impact reduction is achieved in the downstream community of Dingboche with modest (~3 m lake lowering. Lowering the lake by 10 m shows a significant reduction in inundated area. However, lowering the lake by 20 m almost eliminates all flood impact at Dingboche. Further downstream at Phakding, the impact of the GLOF is significant and similar reductions in inundation are likely as a result of lake lowering.

  5. 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.

  6. Spatial and Temporal Dynamics of Virus Occurrence in Two Freshwater Lakes Captured through Metagenomic Analysis

    Directory of Open Access Journals (Sweden)

    Mohammad eMohiuddin

    2015-09-01

    Full Text Available Viruses are the most abundant microorganisms in the aquatic environment, yet the identification of viruses and assessing their diversity still remains a challenge. Here, we present a robust, routinely usable approach to identify viruses from two freshwater lakes of the lower Great Lakes region, Lake Ontario and Lake Erie. We collected water samples from six different beaches of these two lakes during the summer period of 2012 and 2013, and separated into three distinct fractions, namely a bacterial fraction, a virus like particle (VLP fraction and a fraction of eDNA (environmental DNA. DNA extracted from all three fractions was sequenced and bioinformatic analyses of sequences revealed the presence of viruses from major viral families. The analyzed viral sequences were dominated by bacteriophage sequences, but also contained many plant and animal viruses. Within the context of this study, geographic location does not appear to have a major impact on viral abundance and diversity since virome composition of both lakes were similar. Comparative analyses between eDNA and viral fractions showed that eDNA can be used in combination with VLP fractions to identify viruses from the environment.

  7. An integrated assessment for wind energy in Lake Michigan coastal counties.

    Science.gov (United States)

    Nordman, Erik; VanderMolen, Jon; Gajewski, Betty; Isely, Paul; Fan, Yue; Koches, John; Damm, Sara; Ferguson, Aaron; Schoolmaster, Claire

    2015-04-01

    The benefits and challenges of onshore and offshore wind energy development were assessed for a 4-county area of coastal Michigan. Economic, social, environmental, and spatial dimensions were considered. The coastal counties have suitable wind resources for energy development, which could contribute toward Michigan's 10% renewable energy standard. Wind energy is cost-effective with contract prices less than the benchmark energy price of a new coal-fired power plant. Constructing a 100 MW wind farm could have a $54.7 million economic impact. A patchwork of township-level zoning ordinances regulates wind energy siting. Voluntary collaborations among adjacent townships standardizing the ordinances could reduce regulatory complexity. A Delphi Inquiry on offshore wind energy in Lake Michigan elicited considerable agreement on its challenges, but little agreement on the benefits to coastal communities. Offshore turbines could be acceptable to the participants if they reduced pollution, benefited coastal communities, involved substantial public participation, and had minimal impact on property values and tourism. The US Coast Guard will take a risk-based approach to evaluating individual offshore developments and has no plans to issue blanket restrictions around the wind farms. Models showed that using wind energy to reach the remainder of the 10% renewable energy standard could reduce SO2 , NOx , and CO2 pollution by 4% to 7%. Turbines are highly likely to impact the area's navigational and defense radar systems but planning and technological upgrades can reduce the impact. The integrated assessment shows that responsible wind energy development can enhance the quality of life by reducing air pollution and associated health problems and enhancing economic development. Policies could reduce the negative impacts to local communities while preserving the benefits to the broader region.

  8. Forestry and restoration of water bodies. Economic assessment on the basis of lake restoration costs

    International Nuclear Information System (INIS)

    Pollution load to water bodies deriving from forestry activities can regionally be a significant factor deteriorating the state of water bodies. Eutrophication, silting and acidification of water bodies eventually require restoration activities. Restoration of water bodies is expensive and often there is not enough financing available to implement the needed measures. The purpose of this study is to examine the relation between loading and costs of restoration. Restoration costs for different restoration alternatives are estimated using a cost per unit method based on the area and volume of the water body. The share of restoration costs depends on the used restoration method and ranges from 0,1 to 60 % of the total stumpage price that could be gathered from the target forestry area when assessing removal of phosphorus and sediment. The costs were below 1,0 % of the stumpage value when using the most inexpensive restoration methods, precipitation of phosphorus and removal of surface sediment. On the whole, it can be stated that even though restoration costs remain percentually low in comparison with the profit gained from wood production when using the most inexpensive methods, the costs do have significance when considering the water effects of forestry on a larger scale. It has to be observed that the calculated restoration costs are not total costs when estimating the economic significance of water pollution deriving from forestry, because the estimation was based on a cost per unit method, which means that only those components were taken into consideration for which a correlation between forestry-derived pollution and restoration costs could clearly be demonstrated. For example, the costs of brook restoration have not been assessed in this study, even though the pollution to water is heaviest in the brooks and lakes of the headwater region situated in the direct vicinity of the forestry area. In addition, the costs of restoration for fishery purposes are

  9. Assessing the status of endangered invertebrates from the ancient Lake Ohrid: The gastropod Chilopyrgula sturanyi

    OpenAIRE

    Budzakoska-Gjoreska Biljana; Trajanovski S.; Trajanovska Sonja

    2012-01-01

    Lake Ohrid is the oldest and deepest lake on the Balkan Peninsula and one of the five oldest lakes in the world. Two of the most striking attributes of the species of the Lake’s fauna, especially the fauna of gastropods, are the high level of biological diversity as well as a high percentage of endemism. The main subject of interest in our research was to follow the distribution and density of the endemic gastropod species Chilopyrgula sturanyi. For this purpose different depth points o...

  10. Assessment of Ecological Importance and Anthropogenic Change of Subaquatic Springs in Ancient Lake Ohrid

    OpenAIRE

    Jordanoska, Biljana; Stafilov, Trajče; Wüest, Alfred Johny

    2013-01-01

    Apart from their contribution in the water balance of Lake Ohrid, Republic of Macedonia, subaquatic springs are also expected to affect the water quality. A simple experiment was developed and applied to subaquatic spring in Kališta region (south-east of Kališta village, in the north-western part of the Lake) and at the spring at Veli Dab (eastern side of the Lake) based on physicochemical spring water properties. Different sampling methods were established with the aim of uncovering a more s...

  11. Ontario Hydro Research Division annual report 1988

    International Nuclear Information System (INIS)

    The Research Division of Ontario Hydro conducts research in the fields of chemistry, civil engineering, electrical engineering, mechanical engineering, metallurgy, and operations. Much of the research has a bearing on the safe, environmentally benign operation of Ontario Hydro's nuclear power plants. Particular emphasis has been placed on nuclear plant component aging and plant life assurance

  12. Educational Information in Ontario: A Government Perspective.

    Science.gov (United States)

    Hildebrand, B. M.

    The Ontario Ministry of Education's role in funding educational research, and its procedures for the dissemination of educational research information are described. Two ministry initiatives are discussed in detail: the establishment of the Educational Information System for Ontario (EISO), a computerized search and retrieval service to access…

  13. Protectionist Measures in Postsecondary Ontario (Canada) TESL

    Science.gov (United States)

    Jambor, Paul Z.

    2012-01-01

    TESL in Ontario, Canada, seems to be on an inauspicious path by having set up non-tariff protectionist measures in an apparent attempt to keep out a multinational TESL workforce, effectively going against the spirit of globalization. This paper highlights some of the differences between South Korean TEFL and TESL in Ontario; for the most part…

  14. Ontario's Challenge: Denominational Rights in Public Education

    Science.gov (United States)

    Zinga, Dawn

    2008-01-01

    Denominational rights in education have a long and controversial history within Canada. Ontario has struggled with denomination rights and continues to face the challenges posed by accommodating denominational rights. This paper examines those challenges and considers the future of denominational rights in Ontario, in light of John Tory's 2007…

  15. Blood mercury levels among Ontario anglers and sport-fish eaters

    International Nuclear Information System (INIS)

    We conducted two surveys of Ontario (Canada) fishers: a stratified sample of licensed anglers in two Lake Ontario communities (anglers, n=232) and a shore and community-based sample in five Great Lakes' Areas of Concern (AOC eaters, n=86). Among the 176 anglers consuming their catch, the median number of sport-fish meals/year was 34.2 meals and 10.9, respectively, in two communities, with a mean blood total mercury level among these sport-fish consumers of 2.8 μg/L. The vast majority of fish eaten by AOC eaters was from Ontario waters (74%). For AOC eaters, two broad country-of-origin groups were assembled: Euro-Canadians (EC) and Asian-Canadians (AC). EC consumed a median of 174 total fish meals/year and had a geometric mean total mercury level of 2.0 μg/L. Corresponding AC figures were 325 total fish meals/year and 7.9 μg/L. Overall, mercury levels among AOC eaters were higher than in many other Great Lakes populations but lower than in populations frequently consuming seafood. In multivariate models, mercury levels were significantly associated with levels of fish consumption among both anglers and EC AOC eaters. Given the nutritional and social benefits of fish consumption, prudent species and location choices should continue

  16. Buffalo Lake National Wildlife Refuge: Comprehensive Conservation Plan and Environmental Assessment

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on Buffalo Lake National Wildlife Refuge for the next 15 years. This plan outlines the...

  17. An assessment of mercury in waters, sediments and biota of Vermont and New Hampshire lakes [Draft

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The present report summarizes findings of a three-year field study of mercury in freshwater lakes of Vermont and New Hampshire. The study was undertaken jointly by...

  18. Pesticide Impact Assessment in Tule Lake and Lower Klamath National Wildlife Refuges, 1998 - 2000 Growing Season

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Tule Lake and the adjacent Lower Klamath National Wildlife Refuges (TLNWR and LKNWR) serve as key spring/fall staging and overwintering areas for Pacific Flyway...

  19. Final Environmental Assessment : Fisheries and Lake Rehabilitation Plan on St. Vincent National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The U.S. Fish and Wildlife Service proposes to initiate actions to rehabilitate the St. Vincent Island freshwater fishery and lake/marsh system. Five of the...

  20. Phase 1 Watershed Assessment Final Report: Lake Andes Watershed, Charles Mix County, South Dakota.

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Lake Andes was included in the 1998 South Dakota 303(d) list as an impairment-related Total Maximum Daily Load waterbody. In 1922 Congress passed a bill that...

  1. Detroit Lakes Wetlands Management District: Comprehensive Conservation Plan and Environmental Assessment

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on Detroit Lakes Wetlands Management District for the next 15 years. This plan outlines...

  2. Operational Plan and Environmental Assessment for Striped Skunk and Raccoon Management : Benton Lake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The action proposed in this plan is to trap and remove striped skunk and raccoon at Benton Lake National Wildlife Refuge. The purpose of the action is to manage,...

  3. Environmental Assessment Proposal to Protect Wildlife Habitat at Lake Umbagog 1991

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of this United States Fish & Wildlife Service proposal is to ensure the long-term protection of unique wetland habitats adjacent to Lake Umbagog, on...

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

    Data.gov (United States)

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

  5. Final Environmental Assessment for transfer of Indian Lakes area to Churchill County, Nevada

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The USFWS proposes to transfer the Indian Lakes portion of the Stillwater Wildlife Management Area to Churchill County, Nevada for the purposes of fish, wildlife,...

  6. Use of Geoenvironmental Impact of Climate Change in Management and Assessment Lake Nasser, Egypt

    Science.gov (United States)

    Sayed El Gammal, El

    2010-05-01

    This study monitor how to management the water stored after High Dam in the biggest artificial global lake (Lake Nasser), Integration of physical features and water level changes within the lake curse and margins. Statistical data presented, interpreted and correlated with using remote sensing technique in change detection. Different Landsat images acquired at different times (1970, 1982, 1987, 2000, 2003 and 2008) have been used by the ERDAS and ARC-GIS techniques to estimate the movements of lake borders and water fluctuation proportional to water sizes in place. Regards to water fluctuation degree, the lake can be divide into 4 classes in lake's sectors: 1, show maximum change degree, 2 show medium change degree, 3 slight to neglected change degree, and 4, no change. Functions control the water fluctuation in Lake Nasser are; (i) the granite and Nubia sandstone outcrops, (ii) NW, E-W and NE structure in order, (iii) low topography. Water level change detection on Landsat images in different dates elucidates big variation between different lake sectors, there are strangle points and other useful localities that yields environmental implication. The strangle points detected in the curse of River Nile and after 40 years since lake initiation, the water are more strangled in this curse because of the water velocity before the High Dam was high speed can pass toward the north in Nile annual flood but after the dam, the water velocity decreased. Due to decrease of velocity, the water go to narrow incised wadis (Khors) in the Nile high flood plus the sands drift, these khors are bounded by hard Nubia sandstone already saturated by water and it consider the main underground water reservoir in Egypt. In addition, the entrance of the lake in Halfa inside Sudan is subjected to suspended sediments (mud) forming new delta plus the sands drift that impair the reservoir in Egypt. Wadi Allaqui have 250 km length and 2 km average width, it's is the 5th order channel inside a

  7. ASSESSMENT OF HEAVY METALS POLLUTION IN ABIOTIC COMPONENT OF ECOSYSTEM OF VYRLYTSA LAKE

    OpenAIRE

    Bilyk, Tetiana; Padalka, Anastasiia; Shilo, Olga

    2011-01-01

    Abstract. The main task was to investigate the pollution by heavy metals of abiotic component in theVyrlytsa Lake. Was determined the amount of movable form of heavy metals in the water and bottomsediments by the method of atomic absorption spectroscopy. Anthropogenic pollution of the lake is connectedwith discharges of waste waters from enterprises that situated in the industrial zone.Keywords: abiotic component, heavy metals, migration, mobile form.

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

    OpenAIRE

    I. A. Torgoev; Yu. G. Aleshin; S. A. Erokhin

    2015-01-01

    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 a...

  9. Palaeolimnological assessment of lake acidification and environmental change in the Athabasca Oil Sands Region, Alberta

    Directory of Open Access Journals (Sweden)

    Sergi PLA

    2010-08-01

    Full Text Available Exploitation of the Athabasca Oil Sands has expanded hugely over the last 40 years. Regional emissions of oxidised sulphur and nitrogen compounds increased rapidly over this period and similar emissions have been linked to lake acidification in other parts of North America and Europe. To determine whether lakes in the region have undergone acidification, 12 lakes within the Regional Municipality of Wood Buffalo and the Caribou Mountains were selected to cover chemical and spatial gradients and sediment cores were obtained for palaeolimnological analyses including radiometric dating, diatom analysis, isotopic analysis of bulk sediment 13C and 15N, and spheroidal carbonaceous particles (SCPs. All lake sediment cores show evidence of industrial contamination based on SCPs, but there is no clear industrial signal in stable isotopes. Most lakes showed changes in diatom assemblages and sediment C:N ratios consistent with nutrient enrichment over various timescales, with potential drivers including climatic change, forest fires and anthropogenic nitrogen deposition. Only one of the 12 lakes investigated showed strong evidence of acidification with a decline in diatom-inferred pH from 6.3 to 5.6 since 1970 linked to increasing relative abundances of the acidophilous diatom species Actinella punctata, Asterionella ralfsii and Fragilariforma polygonata. Analysis of mercury (Hg in the acidified lake showed increasing sediment fluxes over the last 20 years, a possible indication of industrial contamination. The acidified lake is the smallest of those studied with the shortest residence time, suggesting a limited capacity for neutralisation of acid inputs in catchment soils or by inlake processes.

  10. Mercury concentrations in fish from three major lakes in north Mississippi: Spatial and temporal differences and human health risk assessment.

    Science.gov (United States)

    Wolff, Stacy; Brown, Garry; Chen, Jingjing; Meals, Keith; Thornton, Cammi; Brewer, Steve; Cizdziel, James V; Willett, Kristine L

    2016-01-01

    The goal of this study was to compare total mercury (Hg) concentrations in fish muscle tissue and assess consumption health risks of fish collected from three north Mississippi lakes (Sardis, Enid, and Grenada) that are extensively used for fishing and recreation. Largemouth bass (LMB; n = 64), channel catfish (CC; n = 72), and white crappie (WC; n = 100), which represent a range of trophic levels, were collected during spring 2013 and 2014. Creel data estimated that anglers harvested approximately 370,000 kg of WC, 27,000 kg of CC, and 15,000 kg of LMB from the lakes annually. Median Hg wet weight concentrations were highest in LMB (443 ng/g), followed by CC (211 ng/g) and WC (192 ng/g). Fish-Hg concentrations were lower than those reported in fish >10 years ago. There were significant differences between lakes consistent across species. Grenada length-normalized fish-Hg concentrations were higher than those from Enid and Sardis. Because existing consumption advisories for CC are length based, the lack of relationship between length and Hg concentration indicated that the recommendations may not be sufficiently protective. Further, five different risk assessment paradigms yielded hazard quotient (HQ) values suggesting that existing fish consumption advisories may be insufficient to protect adults and especially children from exposure to Hg. PMID:27644342

  11. Green power opportunities for Ontario

    International Nuclear Information System (INIS)

    Green energy is defined as the energy generated from renewable and environmentally benign sources. In this document, the authors demonstrated that Ontario possesses the potential to reduce energy waste on an economic basis while generating sufficient green energy to enable the province to decommission its coal burning power plants. In turn, this would lead to a more sustainable energy economy and a lesser reliance on nuclear generation. It was determined that a three-fold policy would enable the province to achieve this goal. First, there is a need to remove hidden subsidies to polluting forms of generation. The second aspect of this policy is the implementation of a robust Demand Side Management Program, and the third aspect calls for the reform of the price of electricity that includes all costs. In this manner, all forms of generation would compete on an equal footing. The authors identified an alternative to immediate price reform in the form of a legislated Renewable Portfolio Standard. A growing percentage of new renewable electricity in the supply portfolio offered by electricity providers would be required by the Renewable Portfolio Standard. It was suggested that the Ontario government adopt this measure before the opening of the electricity market in May 2002, as strong support for the measure is present. 13 refs

  12. Tracking past changes in lake-water phosphorus with a 251-lake calibration dataset in British Columbia: tool development and application in a multiproxy assessment of eutrophication and recovery in Osoyoos Lake, a transboundary lake in western North America

    Directory of Open Access Journals (Sweden)

    Brian Fraser Cumming

    2015-08-01

    Full Text Available Recently there has been an active discussion about the potential and challenges of tracking past lake-water trophic state using paleolimnological methods. Herein, we present analyses of the relationship between modern-day diatom assemblages from the surface sediments of 251 fresh-water lakes from British Columbia and contemporary limnological variables. Total phosphorus (TP was significantly related to the modern distribution of diatom assemblages. The large size of this new calibration dataset resulted in higher abundances and occurrences of many diatom taxa thereby allowing a more accurate quantification of the optima of diatom taxa to TP in comparison to previous smaller calibration datasets. Robust diatom-based TP inference models with a moderate predictive power were developed using weighted-averaging regression and calibration. Information from the calibration dataset was used to interpret changes in the diatom assemblages from the north and south basins of Osoyoos Lake, in conjunction with fossil pigment analyses. Osoyoos Lake is a large salmon-bearing lake that straddles the British Columbia-Washington border and has undergone cultural eutrophication followed by recovery due to substantial mitigation efforts in managing sources of nutrients. Both diatom assemblages and sedimentary pigments indicate that eutrophication began c. 1950 in the north basin and c. 1960 in the southern basin, reaching peak levels of production between 1960 and 1990, after which decreases in sedimentary pigments occurred, as well as decreases in the relative abundance and concentrations of diatom taxa inferred to have high TP optima. Post-1990 changes in the diatom assemblage suggests conditions have become less productive with a shift to taxa more indicative of lower TP optima in concert with measurements of declining TP, two of these diatom taxa, Cyclotella comensis and Cyclotella gordonensis, that were previously rare are now abundant.

  13. Benthic diatoms in lakes

    OpenAIRE

    Gottschalk, Steffi

    2014-01-01

    In order to protect or improve surface waters ecosystem response to pressures needs to be quantified. Diatoms are frequently used for assessing ecological status in streams and for reconstructing water quality of lakes. However, ecological status assessment of European lakes based on extant diatom assemblages is rare. The overall aim of this thesis is to facilitate the application of benthic diatoms in water quality assessment of boreal lakes, using methods developed for stream assessmen...

  14. Total cylindrospermopsins, microcystins/nodularins, and saxitoxins data for the 2007 United States Environmental Protection Agency National Lake Assessment

    Science.gov (United States)

    Loftin, Keith A.; Dietze, Julie E.; Meyer, Michael T.; Graham, Jennifer L.; Maksimowicz, Megan M.; Toyne, Kathryn D.

    2016-05-26

    Phytoplankton communities in freshwater lakes, ponds, and reservoirs may be dominated by cyanobacteria (also called blue-green algae) under certain environmental conditions. Cyanobacteria may cause a range of water-quality impairments, including the potential for toxin production. Cyanobacteria toxins (cyanotoxins) may adversely impact human and ecological health. Microcystins are considered to be one of the most commonly found classes of cyanotoxins in freshwater ecosystems, and as such were selected as a recreational indicator of water quality for the 2007 United States Environmental Protection Agency (EPA) National Lakes Assessment. However, much less is known about the occurrence of other classes of cyanotoxins in fresh surface water such as anatoxins, cylindrospermopsins, nodularins, and saxitoxins.

  15. Deregulation and the Alberta experience : the implications for Ontario

    International Nuclear Information System (INIS)

    This paper provides a 15 month assessment of Alberta's new competitive electricity market. It also presents lessons that Ontario customers could learn from Alberta's experience. The goal for restructuring is to achieve lower electricity prices, competitive retail markets, increased flexibility of contracts, and to remove investment risks from consumers. Alberta's restructured market includes power generation, high voltage transmission, low voltage transmission and retail sales. Economists agree that deregulation has brought lower prices and other consumer benefits despite some imperfections. After one year, prices in Alberta have gone down from $130/MWh to $30/MWh. Power supply has increased along with demand response, market competitiveness, liquidity, and thermal and economic efficiency. In 2001, Alberta was a net exporter of electricity. In 2001, it was ranked by the Center for Advancement of Energy Markets (CAEM) which ranks states and provinces by 22 attributes for how they are restructuring their power markets. Alberta ranked first overall in North America. Ontario ranked sixteenth. 4 tabs., 5 figs

  16. The Argentinean network for the assessment and monitoring of Pampean shallow-lakes (PAMPA2)

    Science.gov (United States)

    Zagarese, H. E.

    2012-12-01

    The Pampa region of Argentina is an extensive wetland containing nearly 200,000 shallow-lakes. The region is under increasing agricultural pressure resulting from climate change (increased temperature and precipitation) and the substitution of cattle breeding and traditional cultures by transgenic soy. Among the many services that they provide, shallow-lakes are highly responsive to changes in climate and land use. Therefore, long-term studies of shallow-lakes provide useful clues to understand and track changes occurring in their complex watersheds. PAMPA2 is a recently funded, long-term network project, with wide geographic coverage, aimed at studying Pampean shallow-lakes. Thirteen network sites (i.e., shallow lakes) occurring along the precipitation gradient (from 1000 mm y-1) form the core of the project. The network integrates various research teams from eight universities and research centers, with a strong multidisciplinary component. The approaches combine traditional sampling; high-rate monitoring using automated sensors; and remote sensing. The network develops and manufactures most the instruments, including automated buoys and unmanned aircrafts. In this presentation, we will provide details on the structure and state of development of the PAMPA2 network, and present a long-term case study of a large Pampean shallow-lake, exemplifying the strong dependence of lake processes on weather variables. Laguna Chascomús is a large, hypertrophic shallow-lake. Chascomús is one of the PAMPA2 study sites that have been more extensively studied. In this shallow-lake, high nutrient availability permits the development of a dense microbial plankton community, which in turn translates into exceptionally high water turbidity. Phytoplankton primary production is strongly limited by light availability. As a consequence, turbidity is strongly and positively correlated to the incoming solar radiation, resulting in a remarkable seasonal pattern of water transparency

  17. The Prodigies of The Albano Lake During Roman Age and Natural Hazard Assessment At Roma, Italy.

    Science.gov (United States)

    Funiciello, R.; Giordano, G.; de Rita, D.

    Roma is built just 20 km to the northwest of the Pleistocene Colli Albani volcano, but is believed not exposed to relevant natural hazards, except for the Tiber river flood- ings, and local amplification of seismic waves from distal earthquakes. This belief has generally induced modern historians and geologists to discard as SmythologicalT the & cedil;many references to natural prodigies that are reported by many Roman-age historians. Recent studies have demonstrated that the Albano maar, the youngest volcanic cen- tre of the Colli Albani volcano and presently filled by a 175 m deep lake, protracted its activity to the Holocene triggering several catastrophic lahar events, likely related to lake withdrawal, the deposits of which are exposed to the southwest of Roma and reach its periphery. This finding youngs the history of the volcano and makes it rele- vant to pre-historic settlements, which ScarefullyT avoided the Albano maar slopes up & cedil;to the Bronze age. What is still unknown, though, is whether the lake experienced such fluctuations and overspills during historic times. Several Roman authors such as Ti- tus Livius, Dionigi d'Alicarnasso, Plutarco, Germanico, and many others wrote about the then well known 398 BC prodigious event, when, during the war between Roma and the Etruscan city of Veio, the gods anger caused the sudden rise and overspill of the Albano lake, reported as unrelated to climatic events, and the destructive flooding of the countryside. After that event Romans actually built a tunnel-drain which still operates regulating the lake level at 293 m a.s.l., 70 m below the maar rim elevation. Should those chronicles be truthful, we can join the geologic observation of Holocene lahar deposits from lake withdrawal with historical lake withdrawals, reassessing the natural hazard for the city of Roma under a point of view never explored before. This paper carefully explores the historical credibility of the 398 BC lake overspill event and its

  18. Market readiness update : updated status of preparations for Ontario's competitive retail electricity market

    International Nuclear Information System (INIS)

    The Market Readiness Project Team of the Ontario Energy Board (OEB) is instrumental in ensuring the readiness of retail participants in Ontario's competitive electricity market. The team, led by the Independent Electricity Market Operator (IMO), provides information and advice regarding the technical readiness of the retail industry, with particular focus on the readiness of distributors to carry out their roles in a competitive market. This report provides an assessment of the team regarding the industry's technical readiness based on information as of April 24, 2002. In January 2002, the Ontario Government announced that it would open the electricity industry to competition on May 1, 2002. 54 of Ontario's 94 licensed electricity distributors claimed they were ready to offer retail choice by May 1. As of March 2002, about 858,000 customers (or 20 per cent of Ontario's 4.2 million customers) had signed a retail electricity contract with one of 9 active electricity retailers. By April 2002, 73 distributors, representing 93 per cent of Ontario's customers signed a contract with a retailer. Those customers who choose not to sign a contract will continue to receive service from their distributor but at energy prices set hourly by the IMO. It is expected that after May 1, the transition to a competitive market will proceed for several weeks as distributors progress through their billing cycles. 7 tabs., 2 figs

  19. Temporal Variation of Chemical Persistence in a Swedish Lake Assessed by Benchmarking.

    Science.gov (United States)

    Zou, Hongyan; Radke, Michael; Kierkegaard, Amelie; McLachlan, Michael S

    2015-08-18

    Chemical benchmarking was used to investigate the temporal variation of the persistence of chemical contaminants in a Swedish lake. The chemicals studied included 12 pharmaceuticals, an artificial sweetener, and an X-ray contrast agent. Measurements were conducted in late spring, late autumn, and winter. The transformation half-life in the lake could be quantified for 7 of the chemicals. It ranged from several days to hundreds of days. For 5 of the chemicals (bezafibrate, climbazole, diclofenac, furosemide, and hydrochlorothiazide), the measured persistence was lower in late spring than in late autumn. This may have been caused by lower temperatures and/or less irradiation during late autumn. The seasonality in chemical persistence contributed to changes in chemical concentrations in the lake during the year. The impact of seasonality of persistence was compared with the impact of other important variables determining concentrations in the lake: chemical inputs and water flow/dilution. The strongest seasonal variability in chemical concentration in lake water was observed for hydrochlorothiazide (over a factor of 10), and this was attributable to the seasonality in its persistence. PMID:26171662

  20. Can silicon isotopes be used to assess anthropogenic impacts and nutrient utilisation in Lake Baikal, Siberia?

    Science.gov (United States)

    Swann, G. E. A.; Panizzo, V. N.; Mackay, A. W.; Roberts, S.; Vologina, E.; Horstwood, M. S.

    2014-12-01

    Silicon isotope geochemistry (28Si, 29Si, 30Si) represents a growing field in Earth Sciences providing information to constrain and understand biogeochemical cycling on land and in oceans. Here we present records of δ30Si (30Si/28Si) from the Lake Baikal drainage basin in central Siberia to understand silicon cycling through the dominant river tributaries and into Lake Baikal itself, the world's deepest and most voluminous lake containing one fifth of all freshwater not stored in glaciers and ice caps.Waters were collected along an upstream transect for the five dominant Lake Baikal inflows as well as from the Selenga Delta which account for >50% of the annual riverine flow to the lake. Samples for dissolved silicon (DSi) concentrations and silicon isotopic signatures (δ30SiDSi) were filtered and acidified in the field with isotopic analyses conducted on a Neptune + Multi-Collector ICP-MS using wet plasma mode with Mg doping of samples and standard-sample-standard bracketing. Analytical reproducibility is 0.11‰ (2σ) and blanks are urbanisation, deforestation, agriculture and mining have impacted biogeochemical cycling.

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

    International Nuclear Information System (INIS)

    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.)

  2. Dynamics of Vibrio cholerae abundance in Austrian saline lakes, assessed with quantitative solid-phase cytometry.

    Science.gov (United States)

    Schauer, Sonja; Jakwerth, Stefan; Bliem, Rupert; Baudart, Julia; Lebaron, Philippe; Huhulescu, Steliana; Kundi, Michael; Herzig, Alois; Farnleitner, Andreas H; Sommer, Regina; Kirschner, Alexander

    2015-11-01

    In order to elucidate the main predictors of Vibrio cholerae dynamics and to estimate the risk of Vibrio cholera-related diseases, a recently developed direct detection approach based on fluorescence in situ hybridization and solid-phase cytometry (CARD-FISH/SPC) was applied in comparison to cultivation for water samples from the lake Neusiedler See, Austria and three shallow alkaline lakes over a period of 20 months. Vibrio cholerae attached to crustacean zooplankton was quantified via FISH and epifluorescence microscopy. Concentrations obtained by CARD-FISH/SPC were significantly higher than those obtained by culture in 2011, but were mostly of similar magnitude in 2012. Maximum cell numbers were 1.26 × 10(6) V. cholerae per L in Neusiedler See and 7.59 × 10(7) V. cholerae per L in the shallow alkaline lakes. Only on a few occasions during summer was the crustacean zooplankton the preferred habitat for V. cholerae. In winter, V. cholerae was not culturable but could be quantified at all sites with CARD-FISH/SPC. Beside temperature, suspended solids, zooplankton and ammonium were the main predictors of V. cholerae abundance in Neusiedler See, while in the shallow alkaline lakes it was organic carbon, conductivity and phosphorus. Based on the obtained concentrations a first estimation of the health risk for visitors of the lake could be performed.

  3. Landscape ecological assessment and eco-tourism development in the South Dongting Lake Wetland, China

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    As an important resource and the liying environment of mankind, wetland has become gradually a highlight, strongly concerned andintensively studied by scientists and sociologists.The governments in the world and the whole society have been paying more and more attentionon it.The Dongting Lake of China is regarded as an internationally important wetland.For a rational development and protection of thewetland, an investigation and studied on its resources and its value to tourism in the South Dongting Lake was conducted, to create anassessment system of the ecological landscapes, and to evaluate qualitatively and quantitatively the value of wetland landscape to the eco-tourism.The results showed that the scenic value of the South Dongting Lake Wetland satisfied the criterion of AAAA grade of China nationalscenic attraction.The eco-tourism value of the landscape cultures in the South Dongting Lake Wetland was discussed with emphasis.It wereformulated that a principle and frame of sustainable exploitation of the wetland landscapes and it was proposed as well that establishing aWetland Park and developing eco-tourism in the South Dongting Lake.Wetland is a fragile ecosystem with low resistance to the impact of theexploitation.Thus, we must pay intensively attention to the influence of exploitation on the landscape, take the ecological risk in account toemploy a right countermeasure and avoid the negative affection.

  4. USING MACROZOOBENTHOS TO ASSESS THE ECOLOGICAL CONDITION OF THE STARZYC LAKE (NORTH-WEST POLAND

    Directory of Open Access Journals (Sweden)

    Ryszard Konieczny

    2013-10-01

    Full Text Available In the summer of 2008–2009 species composition and quantity of macrozoobenthos in deposits samples collected with Ekman gripping device at 4 points of Starzyc Lake was studied. Lake Starzyc also called Chociwel is located in West Pomeranian Voivodeship and is adjacent to the town of Chociwel from South and South East of the city. In the collected material of the analysed lake macrozoobenthos organisms from the following classes were found: Oligochaeta, Hirudinea, Crustacea, Insecta and Bivalvia. The Insecta class was the most numerous one in respect of species found, including larvae of the following orders: Ephemeroptera (Leptophlebia sp., Ephemera sp., Caenis macrura (Stephens, Trichoptera (Limnephilidae, Leptoceridae, Cyrnus sp. Diptera and Megaloptera (Sialis lutaria L.. The density and biomass distribution in the analysed Starzyc Lake demonstrates the occurrence of unfavourable changes which may lead to eutrophication in the shallowest layers of the body reservoir and in the zone at the depth of 4.9 m. The littoral zone of the studied lake features high density and significant benthic fauna biomass with low values of PIE biodiversity index.

  5. Precise topography assessment of Lop Nur Lake Basin using GLAS altimeter

    International Nuclear Information System (INIS)

    Lop Nur is a dried-up salt lake lying in the eastern part of Tarim basin, which used to be the second largest lagon in China. The ''ear'' rings in Lop Nur attract many interests and are regarded as the lake shorelines during its recession. The topography of the lake basin is important in understanding the formation of the ''ear'' rings. In this paper, elevation data along three transects obtained from laser altimeter were taken as the basic material of the topography in Lop Nur. Elevation data of laser altimeter show great consistency between adjacent passes. Orthometric height (OH) derived from altimetry data and the geoid model are used to analyze the elevation characteristic along ''ear'' rings. The result shows the ''ear'' rings are basically identical in elevation, supporting the statement that ''ear'' rings are former lake shorelines. A discrepancy of approximately 1 meter in OH is observed on the same ''ear'' ring, lower in the north and higher in the south, which is found for the first time. Possible explanations could be deformation of ground surface due to earthquake or tectonic movement after the ''ear'' rings are formed, or tilt of water surface due to wind stress or lake current during the formation of the rings

  6. Natural and artificial radioactivity assessment of dam lakes sediments in Coruh River, Turkey

    International Nuclear Information System (INIS)

    In the sediment samples collected from 3 different dam reservoirs and 10 different stations on Coruh River, U-238, Th-232, K-40 and Cs-137 activity concentration levels were measured using high-resolution gamma-ray spectrometry. The mean concentrations of U-238, Th-232, K-40 and Cs-137 were found to be 15.8, 13.9, 551.5 and 18.1 Bq/kg in Deriner Dam Lake, 3.7, 12.5, 473.8 and 6.8 Bq/kg in Borcka Dam Lake, 14.4, 30.0, 491.7 and 18.2 Bq/kg in Muratli Dam Lake, respectively. Estimation calculations were made for the non-sampling zones by using Kriging method. Furthermore, results were compared with the similar studies done in different countries. (author)

  7. Charophytes of the lake Garda (Northern Italy: a preliminary assessment of diversity and distribution

    Directory of Open Access Journals (Sweden)

    Rossano Bolpagni

    2013-06-01

    Full Text Available Charophytes (stoneworts and bassweeds are a typical macrophytic component of inland water ecosystems. Well-developed submerged meadows of charophytes are expression of clear water and rather low phytoplankton concentrations. Consequently, among aquatic macroscopic primary producers, charophytes are one of the most threatened groups being very sensitive to phosphorous availability, turbidity and water level perturbations. Accordingly, charophytes have been suffering a massive diversity loss worldwide over the last century, mainly because of human-induced pressures. During summer 2011, detailed field surveys were carried out with the main purpose of filling knowledge gaps concerning aquatic flora and vegetation of the lake Garda – the largest lake in Italy and one of the deepest in Europe. Along randomly selected transects, floristic data were collected following standard procedures, as imposed by the Water Framework Directive. Overall, 12 different species of charophytes were recorded, which accounts for 36% of total Italian charophytes and 19% of European species. The most diffuse species were Chara globularis and C. intermedia; whereas, the most interesting taxa were Chara polyacantha and Nitella hyalina, two species with narrow distribution in Italy. Overall in the lake Garda, dense stands of charophytes covered almost homogeneously the littoral sectors at a water depth between 3 and 12 m. The deepest species was C. globularis, which reached a maximum depth of colonisation of about 17.5 m. Charophytes represent a major element among the primary producers in the lake Garda. The high local charophyte diversity and the rather wide most colonised areas (~1000-1200 ha confirm that the lake Garda is an important reserve for many rare and threatened charophytes. For the first time, these results highlight the key role of the lake Garda for charophyte diversity at a national and European level.

  8. Glacially-streamlined hard and soft beds of the paleo- Ontario ice stream in Southern Ontario and New York state

    Science.gov (United States)

    Eyles, Nick; Doughty, Mike

    2016-06-01

    An extensive tract of glacially-streamlined terrain across a large part of Southern Ontario, Canada, is recognized as the footprint of the paleo-Ontario Ice Stream (OIS) within the easternmost Great Lakes sector of the last Laurentide Ice Sheet. The upstream part is a drumlinized and megagrooved 'hard bed' underlain by Cambro-Ordovician carbonates and sandstones. Subglacial plucking of jointed limestone on the lateral margins of drumlinized escarpment interfluves and rock drumlins generated a large flux of coarse debris within the ice base, recorded by sporadic spreads of hummocky rubble moraine. Downstream, the hard bed passes underneath a streamlined 'soft' bed of till-cored ('drift') drumlins and megaridges of the classic Peterborough and New York State drumlin fields. The boundary between the two bed types is a ~ 10 km wide 'mixed bed' of isolated drift drumlins resting on drumlinized rock suggesting a common erosional origin. Spatial variation in the geomorphology of ~ 2500 drift drumlins, indicates that megaridges are clones resulting from the erosion and dissection of larger parent drumlins. A large moraine system may mark the final collapse and melt of the ice stream, accompanying abrupt flow switching of its margin.

  9. Gas hazard assessment at the Monticchio crater lakes of Mt. Vulture, a volcano in Southern Italy

    OpenAIRE

    Caracausi, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Nuccio, P. M.; Dipartimento CFTA, Universita` di Palermo, Palermo, Italy.; R. Favara; Nicolosi, M.; Dipartimento CFTA, Universita` di Palermo, Palermo, Italy.; Paternoster, M.; Dipartimento Scienze Geologiche, Università della Basilicata.

    2008-01-01

    Geochemical investigations have shown that there is a considerable inflow of gas into both crater lakes of Monticchio, Southern Italy. These lakes are located in two maars that formed 140,000 years ago during Mt. Vulture volcano’s last eruptive activity. Isotopic analyses suggest that CO2 and helium are of magmatic origin; the latter displays 3He/4He isotope ratios similar to those measured in olivines of the maar ejecta. In spite of the fact that the amount of dissolved gases in the water is...

  10. Geophysical data collected from the St. Clair River between Michigan and Ontario, Canada (2008-016-FA)

    Science.gov (United States)

    Denny, Jane F.; Foster, D.S.; Worley, C.R.; Irwin, Barry J.

    2011-01-01

    In 2008, the U.S. Geological Survey (USGS), Woods Hole Coastal and Marine Science Center (WHCMSC), in cooperation with the U.S. Army Corps of Engineers conducted a geophysical and sampling survey of the riverbed of the Upper St. Clair River between Port Huron, Mich., and Sarnia, Ontario, Canada. The objectives were to define the Quaternary geologic framework of the riverbed of the St. Clair River to evaluate the relationship between morphologic change of the riverbed and underlying stratigraphy. This report presents the geophysical and sample data collected from the St. Clair River, May 29-June 6, 2008, as part of the International Upper Great Lakes Study, a 5-year project funded by the International Joint Commission of the United States and Canada to examine whether physical changes in the St. Clair River are affecting water levels within upper Great Lakes, to assess regulation plans for outflows from Lake Superior, and to examine the potential effect of climate change on the Great Lakes water levels (http://www.iugls.org). This document makes available the data that were used in a separate report, U.S. Geological Survey Open-File Report 2009-1137, which detailed the interpretations of the Quaternary geologic framework of the region. This report includes a description of the high-resolution acoustic and sediment-sampling systems that were used to map the morphology, surficial sediment distribution, and underlying geology of the Upper St. Clair River during USGS field activity 2008-016-FA (http://quashnet.er.usgs.gov/cgi-bin/datasource/public_ds_info.pl?fa=2008-016-FA). Video and photographs of the riverbed were also collected and are included in this data release. Future analyses will be focused on substrate erosion and its effects on river-channel morphology and geometry. Ultimately, the International Upper Great Lakes Study will attempt to determine where physical changes in the St. Clair River affect water flow and, subsequently, water levels in the Upper Great

  11. An assessment of the utility of optically-stimulated luminescence to date sediments from Lakes Malawi, Bosumtwi, and Tanganyika, Africa

    Science.gov (United States)

    Gomez, J.; Forman, S. L.; Pierson, J.; Scholz, C.; Peck, J.; Heil, C.; King, J.; Shanahan, T.; Overpeck, J.; Koeberl, C.; Milkereit, B.

    2005-12-01

    An exciting recent development in geochronology is the advent of optically-stimulated luminescence (OSL) for dating late Quaternary sediments. OSL signal of mineral grains is reset by exposure to sunlight prior to deposition and a time-sensitive charge is acquired from exposure to ionizing radiation post burial. The OSL signal is highly sensitive to solar resetting, with background counts rendered after few minutes of sunlight exposure. OSL geochronology can yield decadal resolution in the past 1000 years, a period of limited precision for radiocarbon dating and potentially date sediment spanning the past 200 to 400 ka. Nearly continuous sedimentary records from African lakes provide unparalleled opportunities to develop new OSL dating approaches to constrain hydro-climatic events in the tropics. A variety of OSL geochronologic approaches are attempted for sediments from Lakes Malawi, Bosumtwi and Tanganyika providing an internal test of reproducibility. Accuracy is assessed by OSL dating levels with radiocarbon ages and with correlated chronologic control e.g. from the sediment magnetic signature or sediment carbon to atmosphere methane relations. The fine-grained (3-11 micron) polymineral and quartz fractions and for coarser levels the quartz fine sand is extracted for dating. Additive and regenerative dose procedures using multiple and single aliquots under blue, green and infrared light exposure are used to estimate the post-burial paleodose. A regenerative procedure with dose normalization and stepped preheating (140-180° C) provides a particularly robust approach for dating sediments greater than 75 ka. OSL emissions for sediment from Lake Malawi for the past ca. 100 ka are not at saturated dose and are amenable for dating by a variety of methods. In contrast sediments from Lake Bosumtwi, with a probable Sahel dust source, exhibit saturation in OSL signal for sediments ca. 100 ka old, necessitating the using of regenerative approaches. The concordance

  12. Assessing the status of endangered invertebrates from the ancient Lake Ohrid: The gastropod Chilopyrgula sturanyi

    Directory of Open Access Journals (Sweden)

    Budzakoska-Gjoreska Biljana

    2012-01-01

    Full Text Available Lake Ohrid is the oldest and deepest lake on the Balkan Peninsula and one of the five oldest lakes in the world. Two of the most striking attributes of the species of the Lake’s fauna, especially the fauna of gastropods, are the high level of biological diversity as well as a high percentage of endemism. The main subject of interest in our research was to follow the distribution and density of the endemic gastropod species Chilopyrgula sturanyi. For this purpose different depth points of the transect Hydrobiological Institute-Radozda as well as other littoral points on the northwestern part of Lake Ohrid, were investigated. The results showed maximum density in the population of Chilopyrgula sturanyi in the muddy lakebed covered by Chara tomentosa. The minimum density in population was recorded on the lakebed with gravel. Specimens of Chilopyrgula sturanyi were not recorded at the depth of 50 m, where the lakebed is covered by a sandy-muddy substrate.

  13. Preliminary cleanup activities at vicinity properties near Salt Lake City, Utah: Environmental assessment

    International Nuclear Information System (INIS)

    This document describes the preliminary cleanup activities and their impacts for the approximately 100 properties in Salt Lake Valley that have been contaminated by radioactive tailings from the site of the inactive Vitro uranium mill. The 23 properties already included on the official list for cleanup have been used as the basis for estimating impacts at all 100 sites

  14. Wetland Ecosystem Function Assessment and The Sustainable Development in Jianghan Plain-Lake District of China

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Wetlands in Jianghan plain-lake district fulfill many uses and functions related to hydrology, waste assimilation, ecosystem productivity and bio-diversity. But human incorrect activities generally result in significant negative impacts on number, biodiversity, and functioning of wetlands. In order to put wetland resources to rational use and protect wetland ecological environment, some effective measures should be taken.

  15. Assessment of Toxic Metals and feed habits of the snail Pomacea specie from the Amatitlan Lake

    International Nuclear Information System (INIS)

    In the present thesis an assesment of cadmium, cooper, cromium VI, and lead was made in samples of snail pomacea specie from the Amatitlan Lake. We conclude that the comsuption of this mollusk is toxic for human health. The concentration of heavy metals like cadmium, cooper shows that are not recomended for human comsuption according to Spanish and FAO/PAHO standards

  16. ASSESSMENT OF MERCURY IN HYPOLIMNETIC LAKE SEDIMENTS OF VERMONT AND NEW HAMPSHIRE

    Science.gov (United States)

    The research is to characterize concentrations of total methylmercury in waters and surficial sediments of Vermont and New Hampshire lakes, and to relate these data to commonly measured water column chemical parameters and watershed-level physical attributes. The primary goal of...

  17. A simple DEM assessment procedure for gully system analysis in the Lake Manyara area, northern Tanzania

    NARCIS (Netherlands)

    Maerker, Michael; Quénéhervé, Geraldine; Bachofer, Felix; Mori, Simone

    2015-01-01

    Gully erosion is a major threat concerning landscape degradation in large areas along the northern Tanzanian Rift valley. It is the dominant erosion process producing large parts of the sediments that are effectively conducted into the river network. The study area is located in the Lake Manyara—

  18. Insight conference reports : Ontario power summit

    International Nuclear Information System (INIS)

    The papers presented at this conference described the changes within Ontario's newly opened electricity markets and the lessons learned from other jurisdictions. The switch to open competition in Ontario on May 1, 2002 has been met with supply challenges and power generating capacity challenges. Open competition generally brings down electricity prices, but open markets in Ontario have experienced the contrary. The factors that contributed to the creation of an open electricity market in Ontario were described with reference to the unsustainable electricity rates of the 1990s. Participants at the conference also expressed their views regarding future electricity prices, and presented suggestions of how power transmission, distribution and generation can be optimized while protecting the consumer. The conference featured 16 papers, of which 7 were indexed separately for inclusion in this database. refs., tabs., figs

  19. Western Ontario: Waterfowl breeding population survey: 1998

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for western Ontario during 1998. The primary purpose of the survey is to provide...

  20. Trio Estonia esineb Lõuna-Ontarios

    Index Scriptorium Estoniae

    2012-01-01

    Lõuna-Ontario muusikahuvilistel on tänu Eesti Sihtkapitalile Kanadas ja Cathedral Bluffs sümfooniaorkestrile harukordne võimalus saada oktoobrikuus osa kõrgetasemelise Trio Estonia musitseerimisest

  1. Further Constraints on the Smoothness of Ontario Lacus using Cassini RADAR Specular Reflection Data

    Science.gov (United States)

    Wye, Lauren; Zebker, H. A.; Lorenz, R. D.; Lunine, J. I.; Cassini RADAR Team

    2009-09-01

    Cassini RADAR altimetry data collected on the 49th flyby of Titan (T49; 2008 December 21) over Ontario Lacus in Titan's south polar region shows evidence for intense mirror-like specular reflections. Analysis of the strength of the specular return, which is expected to decline exponentially with increasing surface height variance, reveals that the surface is extremely smooth, with less than 3 mm rms surface height variation over the 100m-wide Fresnel zone ("Smoothness of Titan's Ontario Lacus: Constraints from Cassini RADAR specular reflection data", GRL 2009). The T49 echoes were stronger than expected, severely saturating the receiver and inhibiting an accurate estimation of the signal strength and, consequently, the rms surface height. While we developed a method to partially correct the echoes for the distortion incurred, our height estimate is only an upper limit. Further altimetry data over Ontario Lacus is expected in the T60 sequence on August 9th, 2009, where the receiver attenuation will be set high enough over the lake to avoid saturation, and quantization effects will also be minimized. In this presentation, we will report our latest estimates on the smoothness of Ontario Lacus’ surface and what they might suggest for limitations on the wind speeds or surface material characteristics. This work was conducted under contract with the Cassini Project and was partially supported by NASA headquarters under the NASA Earth and Space Science Fellowship Program.

  2. X-ray safety in Ontario

    International Nuclear Information System (INIS)

    In July 1979 the Ontario Advisory Committee on Radiology was formed to develop a comprehensive strategy for x-ray safety in the province. At its hearings the committee recieved submissions from groups representing physicians, dentists, chiropractors, radiological technicians, physiotherapists, podiatrists, and consumers, among others; these briefs are included as appendices to the report. The report surveys the historical background and the current situation in Ontario, and makes recommendations for an organized safety program. (L.L.)

  3. Market prices for solar electricity in Ontario

    International Nuclear Information System (INIS)

    The Ontario electricity supply is facing considerable challenges while demand is increasing due to a growing population and increased economic growth needs. In response to these challenges, the government of Ontario established the Ontario Power Authority (OPA) in 2004 to ensure adequate, reliable and secure electricity supply and resources in Ontario. The OPA has also engaged in activities to facilitate the diversification of sources of electricity supply by promoting the use of cleaner energy sources and technologies, including alternative energy sources and renewable energy. The purpose of this paper was to advance discussions regarding the contribution that solar PV can make to Ontario's supply mix. In particular, it determined the value of the electricity that would have been produced by a PV system located in Waterloo, Ontario under the following 4 pricing regimes: (1) the conventional small user tariff system currently in place in Ontario, (2) the time-of-use pricing system that is voluntarily available to those who have smart meters installed in their facilities, (3) the spot market, hourly prices, to which some of Ontario's largest electricity users are exposed, and (4) the recently-proposed rate for standard offer contracts for PV systems. The study showed that a solar PV system that produces 3,000 kWh of electricity over the course of a year would generate different revenue amounts, ranging from the smallest amount of approximately $174.00 to $1,260.00, depending on the pricing regime. The pricing regime that reflects real, time-of-day electricity prices appears to be most advantageous to solar PV systems. It was recommended that additional work is needed regarding the other benefits of solar PV, such as avoided capacity/generation needs, avoided transmission and distribution cost and losses, environmental benefits, and job creation. 3 refs., 4 tabs., 8 figs

  4. Epidemiology of Enterovirus D68 in Ontario

    OpenAIRE

    Adriana Peci; Anne-Luise Winter; Bryna Warshawsky; Booth, Tim F; AliReza Eshaghi; Aimin Li; Stephen Perusini; Romy Olsha; Alex Marchand-Austin; Erik Kristjanson; Gubbay, Jonathan B.

    2015-01-01

    In August 2014, children's hospitals in Kansas City, Missouri and Chicago, Illinois notified the Centers for Disease Control and Prevention (CDC) about increased numbers of pediatric patients hospitalized with severe respiratory illness (SRI). In response to CDC reports, Public Health Ontario Laboratories (PHOL) launched an investigation of patients being tested for enterovirus D-68 (EV-D68) in Ontario, Canada. The purpose of this investigation was to enhance our understanding of EV-D68 epide...

  5. Smart Generation : powering Ontario with renewable energy

    Energy Technology Data Exchange (ETDEWEB)

    Etcheverry, J.; Gipe, P.; Kemp, W.; Samson, R.; Vis, M.; Eggertson, B.; McMonagle, R.; Marchildon, S.; Marshall, D.

    2004-10-01

    This report describes how Ontario can develop renewable energy sources to replace fossil fuels currently used for heating and cooling homes. A switch to renewable energy to power the electricity system would promote energy efficiency and conservation and would add $9 billion to the Ontario economy by 2010. An added benefit would be a more reliable electricity system and cleaner air. The economic benefits of the 5 main sources of renewable energy were discussed. These included wind, hydropower, biomass, geothermal and solar energy. Specific policy recommendations for rebuilding Ontario's electricity system with these renewable energy sources were presented. The report showed how Ontario could install 8,000 MW of wind power by 2012 and generate 9 per cent of current electricity demand. Farmers view wind energy as a new cash crop because they can earn thousands of dollars per year by installing wind turbines on their farms. The Ontario government has responded to public concerns about air pollution by promising to close down five coal-fired power plants by 2007. The closures will result in an imbalance between electricity supply and demand. The imbalance of about 7,500 MW can be filled with cheaper and more reliable renewable energy. Canada's first full-scale solar manufacturing plant was built in Cambridge, Ontario and was operational in June 2004. The report suggests that Ontario can install more than 12,000 MW of renewable energy by 2020, enough to phase out coal plants in Ontario. The economic benefits of installing 8,000 MW of wind energy are in the order of $14 billion. refs., tabs., figs.

  6. Radon gas, bronchogenic carcinoma - Ontario experience

    International Nuclear Information System (INIS)

    A review of the procedures followed by the Ontario Worker's Compensation Board in paying insurance benefits to injured workers is presented. Topics include initial methods of handling lung cancer claims, the first guidelines for adjudication of lung cancer, the present guidelines, and a perspective on occupational lung cancers. The Ontario Board has accepted the cause-effect relationship between radon gas decay products and the development of certain bronchogenic carcinomas in those persons so exposed

  7. Model project for the pollution investigation of a lake. The use of nuclear techniques for environmental risk assessment

    International Nuclear Information System (INIS)

    Environmental pollution monitoring and the protection of water resources are vital in terms of public health and economical consequences for many of the countries. The use of nuclear and isotopic techniques for pollution investigation of water resources on the other hand has been gaining more importance during the recent years. In recognition of the serious pollution problems of the surface water resources; a large scope multidisciplinary environmental management project with short title 'Lake Project' which is designed and developed by the group of scientists at the Cekmece Nuclear Research and Training Center of the Turkish Atomic Energy Authority is presented. This multidisciplinary project has various important aspects; scientific, social, economic, educational, cultural and political. Specific problem a dressed was the serious pollution of Kucukcekmece Lake due to high population and industrial growth in the region as well as creation of public awareness on the peaceful activities of the Cekmece Nuclear Research Center. The main objective was to promote the use of nuclear and isotopic techniques in the assessment of local, national and regional environmental pollution control and management. The project implementation was carried out in two phases and supported by the International Atomic Energy Agency. Water, biota and sediment samples were collected from several sampling stations seasonally. Some of the results are presented in tables for natural radioactivity, chemical and physical parameters. The first phases of the project has provided tools and methods for identifying types and magnitudes of contaminants in the Kucukcekmece Lake. Results obtained from the model project show that the radioactivity pollution levels have no significance in terms of human health and ecosystem. However, major problem regarding lake and marine environmental management is identified as eutrophication. This is a process of water quality degradation caused by mainly by domestic

  8. Suvemaja, Antler Island, Fairy Lake, Ontario / Ants Elken

    Index Scriptorium Estoniae

    Elken, Ants, 1917-2012

    1997-01-01

    Tuli projekteerida suvila kasvavale perele, mis algusest peale kasutamiskõlblikuna areneks koos perekonna laienemisega. Kerged paviljonid meenutavad küla. Ehitati 1966-1989. Arhitekt Elmar Tampõld. Joonised, vaated.

  9. Quality legislation: lessons for Ontario from abroad.

    Science.gov (United States)

    Veillard, Jérémy; Tipper, Brenda; Klazinga, Niek

    2012-01-01

    While the Excellent Care for All Act, 2010 (ECFA Act) provides a comprehensive approach to stimulating quality improvement in healthcare, there are other examples of legislations articulating strategies aimed at the same goal but proposing different approaches. This paper reviews quality of care legislations in the Netherlands, the United States, England and Australia, compares those pieces of legislation with the ECFA Act and suggests lessons for Ontario in planning the next stages of its healthcare quality strategy. Notable among the commonalities that the EFCA Act shares with the selected examples of legislation are mandatory reporting of performance results at an organizational level and furthering quality improvement, evidence generation and performance monitoring. However, the EFCA Act does not include any elements of restructuring or competition, unlike some of the other examples. Key to successful transformation of the Ontario healthcare system will be to propose a package of changes that will deal systematically with all aspects of transformation sought (including structural changes, payments systems and elements of competition), will garner support from all the actors, and will be implemented consistently and persistently. Benchmarking on the implementation and impact of reforms with the countries presented in this paper may be an additional important step. Quality of care is a key focus of health system reforms, and in recent years many countries in the Organisation of Economic Co-operation and Development (OECD), including Canada, have developed strategies aimed at improving healthcare quality and patient safety (OECD 2010). Øvretveit and Klazinga propose that national strategies for quality of care can be targeted at different types of health system stakeholders: professionals, healthcare organizations, medical products and technologies, patients and financers (World Health Organization Regional Office for Europe 2008). The generic elements of these

  10. Perchlorate in the Great Lakes: isotopic composition and origin.

    Science.gov (United States)

    Poghosyan, Armen; Sturchio, Neil C; Morrison, Candice G; Beloso, Abelardo D; Guan, Yunbin; Eiler, John M; Jackson, W Andrew; Hatzinger, Paul B

    2014-10-01

    Perchlorate is a persistent and mobile contaminant in the environment with both natural and anthropogenic sources. Stable isotope ratios of oxygen (δ(18)O, Δ(17)O) and chlorine (δ(37)Cl) along with the abundance of the radioactive isotope (36)Cl were used to trace perchlorate sources and behavior in the Laurentian Great Lakes. These lakes were selected for study as a likely repository of recent atmospheric perchlorate deposition. Perchlorate concentrations in the Great Lakes range from 0.05 to 0.13 μg per liter. δ(37)Cl values of perchlorate from the Great Lakes range from +3.0‰ (Lake Ontario) to +4.0‰ (Lake Superior), whereas δ(18)O values range from -4.1‰ (Lake Superior) to +4.0‰ (Lake Erie). Great Lakes perchlorate has mass-independent oxygen isotopic variations with positive Δ(17)O values (+1.6‰ to +2.7‰) divided into two distinct groups: Lake Superior (+2.7‰) and the other four lakes (∼+1.7‰). The stable isotopic results indicate that perchlorate in the Great Lakes is dominantly of natural origin, having isotopic composition resembling that measured for indigenous perchlorate from preindustrial groundwaters of the western USA. The (36)Cl/Cl ratio of perchlorate varies widely from 7.4 × 10(-12) (Lake Ontario) to 6.7 × 10(-11) (Lake Superior). These (36)ClO4(-) abundances are consistent with an atmospheric origin of perchlorate in the Great Lakes. The relatively high (36)ClO4(-) abundances in the larger lakes (Lakes Superior and Michigan) could be explained by the presence of (36)Cl-enriched perchlorate deposited during the period of elevated atmospheric (36)Cl activity following thermonuclear bomb tests in the Pacific Ocean. PMID:25171443

  11. Using integrated multivariate statistics to assess the hydrochemistry of surface water quality, Lake Taihu basin, China

    Directory of Open Access Journals (Sweden)

    Xiangyu Mu

    2014-09-01

    Full Text Available Natural factors and anthropogenic activities both contribute dissolved chemical loads to  lakes and streams.  Mineral solubility,  geomorphology of the drainage basin, source strengths and climate all contribute to concentrations and their variability. Urbanization and agriculture waste-water particularly lead to aquatic environmental degradation. Major contaminant sources and controls on water quality can be asssessed by analyzing the variability in proportions of major and minor solutes in water coupled to mutivariate statistical methods.   The demand for freshwater needed for increasing crop production puulation and industrialization occurs almost everywhere in in China and these conflicting needs have led to widespread water contamination. Because of heavy nutrient loadings from all of these sources, Lake Taihu (eastern China notably suffers periodic hyper-eutrophication and drinking water deterioration, which has led to shortages of freshwater for the City of Wuxi and other nearby cities. This lake, the third largest freshwater body in China, has historically beeen considered a cultural treasure of China, and has supported long-term fisheries. The is increasing pressure to remediate the present contamination which compromises both aquiculture and the prior economic base centered on tourism.  However, remediation cannot be effectively done without first characterizing the broad nature of the non-point source pollution. To this end, we investigated the hydrochemical setting of Lake Taihu to determine how different land use types influence the variability of surface water chemistry in different water sources to the lake. We found that waters broadly show wide variability ranging from  calcium-magnesium-bicarbonate hydrochemical facies type to mixed sodium-sulfate-chloride type. Principal components analysis produced three principal components that explained 78% of the variance in the water quality and reflect three major types of water

  12. Assessment of Water Quality of Lakes for Drinking and Irrigation Purposes in Raipur City, Chhattisgarh, India

    Directory of Open Access Journals (Sweden)

    Sumant Kumar

    2015-02-01

    Full Text Available Lake water is an important source for drinking, domestic and irrigation purposes in rural and urban India. The present study aims at evaluating the water quality of various lakes in Raipur city, Chhatisgarh. There existed 154 lakes in the city but it shrinked to 85 in number due to encroachment or drying up of lakes. Twenty seven prominent lakes are selected to study and evaluate the water quality for drinking and irrigation purposes. The water samples were collected and analysed for pH, Turbidity, Electrical Conductivity (EC, Total Dissolved Solids (TDS, Alkalinity, Hardness, Sodium(Na+ , Potassium(K+ , Calcium(Ca2+ , Magnesium(Mg2+ , Bicarbonate(HCO3- , Sulphate (SO4 2- , Nitrate (NO3 − ,Phosphate(PO4 3- Fluoride(F- , Chloride (Cl− , Chemical Oxygen Demand (COD, Biochemical Oxygen Demand (BOD, Dissolved Oxygen (DO, Total Coliform (TC and Fecal Coliform (FC. There are variations for pH (6.59-8.29, EC (382-2330μS/cm, Turbidity (1-232 NTU, TDS (244-1491 mg/L, Alkalinity (120-600 mg/L, Hardness (66-330mg/L, Na+ (37-430 mg/L, K+ (8- 253 mg/L, Ca2+ (9-90 mg/L, Mg2+ (3-26 mg/L, SO4 2- (5-200 mg/L, NO3 - (0-19 mg/L, PO4 3- (0.19-5.3 mg/L, F -( 0.18-1.41 mg/L and Cl- (46-388 mg/L, DO(1-8.6 mg/L, BOD (0.1-11.3 mg/L, COD (8-118 mg/L, Total Coliform( 15-3600 MPN/100ml and Fecal Coliform (4-240 MPN/100 ml. The results have been compared with the drinking water standard prescribed by Bureau of Indian Standard (BIS. All the physiochemical parameters are within the prescribed limit except turbidity, fecal & total coliform. The Sodium Adsorption Ratio (SAR and salinity hazards are studied to classify the water for irrigation uses. It is found that lake water is suitable for irrigation purposes.

  13. Evaluation of Multi-Resolution Satellite Sensors for Assessing Water Quality and Bottom Depth of Lake Garda

    Directory of Open Access Journals (Sweden)

    Claudia Giardino

    2014-12-01

    Full Text Available In this study we evaluate the capabilities of three satellite sensors for assessing water composition and bottom depth in Lake Garda, Italy. A consistent physics-based processing chain was applied to Moderate Resolution Imaging Spectroradiometer (MODIS, Landsat-8 Operational Land Imager (OLI and RapidEye. Images gathered on 10 June 2014 were corrected for the atmospheric effects with the 6SV code. The computed remote sensing reflectance (Rrs from MODIS and OLI were converted into water quality parameters by adopting a spectral inversion procedure based on a bio-optical model calibrated with optical properties of the lake. The same spectral inversion procedure was applied to RapidEye and to OLI data to map bottom depth. In situ measurements of Rrs and of concentrations of water quality parameters collected in five locations were used to evaluate the models. The bottom depth maps from OLI and RapidEye showed similar gradients up to 7 m (r = 0.72. The results indicate that: (1 the spatial and radiometric resolutions of OLI enabled mapping water constituents and bottom properties; (2 MODIS was appropriate for assessing water quality in the pelagic areas at a coarser spatial resolution; and (3 RapidEye had the capability to retrieve bottom depth at high spatial resolution. Future work should evaluate the performance of the three sensors in different bio-optical conditions.

  14. Evaluation of multi-resolution satellite sensors for assessing water quality and bottom depth of Lake Garda.

    Science.gov (United States)

    Giardino, Claudia; Bresciani, Mariano; Cazzaniga, Ilaria; Schenk, Karin; Rieger, Patrizia; Braga, Federica; Matta, Erica; Brando, Vittorio E

    2014-01-01

    In this study we evaluate the capabilities of three satellite sensors for assessing water composition and bottom depth in Lake Garda, Italy. A consistent physics-based processing chain was applied to Moderate Resolution Imaging Spectroradiometer (MODIS), Landsat-8 Operational Land Imager (OLI) and RapidEye. Images gathered on 10 June 2014 were corrected for the atmospheric effects with the 6SV code. The computed remote sensing reflectance (Rrs) from MODIS and OLI were converted into water quality parameters by adopting a spectral inversion procedure based on a bio-optical model calibrated with optical properties of the lake. The same spectral inversion procedure was applied to RapidEye and to OLI data to map bottom depth. In situ measurements of Rrs and of concentrations of water quality parameters collected in five locations were used to evaluate the models. The bottom depth maps from OLI and RapidEye showed similar gradients up to 7 m (r = 0.72). The results indicate that: (1) the spatial and radiometric resolutions of OLI enabled mapping water constituents and bottom properties; (2) MODIS was appropriate for assessing water quality in the pelagic areas at a coarser spatial resolution; and (3) RapidEye had the capability to retrieve bottom depth at high spatial resolution. Future work should evaluate the performance of the three sensors in different bio-optical conditions.

  15. Biology and status of the shortnose cisco Coregonus reighardi Koelz in the Laurentian Great Lakes

    Science.gov (United States)

    Webb, Shane A.; Todd, Thomas N.

    1995-01-01

    The shortnose cisco, Coregonus reighardi, a member of the endemic species assemblage of Coregoninae in the Laurentian Great Lakes, was commercially important until overfishing and competition pressures from induced planktivores extirpated the species in Lakes Michigan and Ontario. Spawning shortnose ciscoes have been collected from Lake Huron and Georgian Bay of Lake Huron since 1956, however, no individuals have been collected from these habitats since 1985. Shortnose ciscoes were not collected during surveys of the cisco fishery of Georgian Bay during the summer of 1992 and spring of 1993. The lack of captures in the last eight years coupled with captures of only lone individuals in the last 16 years suggests the species may be extinct in all of the Laurentian system. The life history traits examined for Lake Huron shortnose ciscoes were similar to the conditions recorded for Lake Michigan and Ontario shortnose ciscoes, although Lake Huron fish were smaller.

  16. Assessment of water-quality data from Long Lake National Wildlife Refuge, North Dakota--2008 through 2012

    Science.gov (United States)

    Tangen, Brian A.; Finocchiaro, Raymond G.; Gleason, Robert A.; Rabenberg, Michael J.; Dahl, Charles F.; Ell, Mike J.

    2013-01-01

    ong Lake National Wildlife Refuge, located in south-central North Dakota, is an important habitat for numerous migratory birds and waterfowl, including several threatened or endangered species. The refuge is distinguished by Long Lake, which is approximately 65 square kilometers and consists of four primary water management units. Water levels in the Long Lake units are maintained by low-level dikes and water-control structures, which after construction during the 1930s increased the water-storage capacity of Long Lake and reduced the frequency and volume of flushing flows downstream. The altered water regime, along with the negative precipitation:evaporation ratio of the region, may be contributing to the accumulation of water-borne chemical constituents such as salts, trace metals, and other constituents, which at certain threshold concentrations may impair aquatic plant, invertebrate, and bird communities of the refuge. The refuge’s comprehensive conservation planning process identified the need for water-quality monitoring to assess current (2013) conditions, establish comparative baselines, evaluate changes over time (trends), and support adaptive management of the wetland units. In 2008, the U.S. Geological Survey, U.S. Fish and Wildlife Service, and North Dakota Department of Health began a water-quality monitoring program at Long Lake National Wildlife Refuge to address these needs. Biweekly water-quality samples were collected for ions, trace metals, and nutrients; and in situ sensors and data loggers were installed for the continuous measurement of specific conductance and water depth. Long Lake was characterized primarily by sodium, bicarbonate, and sulfate ions. Overall results for total alkalinity and hardness were 580 and 329 milligrams per liter, respectively; thus, Long Lake is considered alkaline and classified as very hard. The mean pH and sodium adsorption ratio for Long Lake were 8.8 and 10, respectively. Total dissolved solids concentrations

  17. Assessment of synthetic organic compounds, and endocrinology and histology of carp in Lake Mead

    Energy Technology Data Exchange (ETDEWEB)

    Bevans, H.; Goodbred, S.; Miesner, J.

    1995-12-31

    This study investigated the presence and biologic effects of synthetic organic compounds transported by Las Vegas Wash to Lake Mead National Recreation Area. Water, bottom sediment, and carp (Cyprinus carpio) were analyzed for synthetic organic compounds. Semipermeable membrane devices (SPMDs) were used to sample the water column. Blood samples were collected from Carp for analysis of sex steroid hormones and vitellogenin. Samples of external abnormalities and organs (liver, gill, kidney, small intestine, and gonad) were collected for histologic analysis. Compounds known to affect endocrine systems (PAHs, phthalate esters, PCBs, dioxins and furans) were detected in SPMD, bottom-sediment, and/or carp samples. The number and concentrations of compounds generally were greater in samples from Las Vegas Wash and Bay, than in samples from Callville Bay, a reference site in Lake Mead. High levels of PAHs detected in SPMDs from Callville Bay could indicate the existence of contaminant sources other than Las Vegas Wash.

  18. Assessing and addressing the re-eutrophication of Lake Erie: central basin hypoxia

    Science.gov (United States)

    Scavia, Donald; Allan, J. David; Arend, Kristin K.; Bartell, Steven; Beletsky, Dmitry; Bosch, Nate S.; Brandt, Stephen B.; Briland, Ruth D.; Daloğlu, Irem; DePinto, Joseph V.; Dolan, David M.; Evans, Mary Anne; Farmer, Troy M.; Goto, Daisuke; Han, Haejin; Höök, Tomas O.; Knight, Roger; Ludsin, Stuart A.; Mason, Doran; Michalak, Anna M.; Richards, R. Peter; Roberts, James J.; Rucinski, Daniel K.; Rutherford, Edward; Schwab, David J.; Sesterhenn, Timothy M.; Zhang, Hongyan; Zhou, Yuntao

    2014-01-01

    Relieving phosphorus loading is a key management tool for controlling Lake Erie eutrophication. During the 1960s and 1970s, increased phosphorus inputs degraded water quality and reduced central basin hypolimnetic oxygen levels which, in turn, eliminated thermal habitat vital to cold-water organisms and contributed to the extirpation of important benthic macroinvertebrate prey species for fishes. In response to load reductions initiated in 1972, Lake Erie responded quickly with reduced water-column phosphorus concentrations, phytoplankton biomass, and bottom-water hypoxia (dissolved oxygen 2) requires cutting total phosphorus loads by 46% from the 2003–2011 average or reducing dissolved reactive phosphorus loads by 78% from the 2005–2011 average. Reductions to these levels are also protective of fish habitat. We provide potential approaches for achieving those new loading targets, and suggest that recent load reduction recommendations focused on western basin cyanobacteria blooms may not be sufficient to reduce central basin hypoxia to 2000 km2.

  19. Value Assessment of the Lake Honghu Wetland and Protection of Its Biodiversity

    Institute of Scientific and Technical Information of China (English)

    Wang Xuelei; Du Yun

    2002-01-01

    A wetland ecosystem's value may be considered as the value derived from its natural resources, the value derived from its eco-environment, the value for special protection and values in cultural, research and educational aspects. Lake Honghu, in the heartland of Hubei Province, covers a vast but shallow body of water and surrounding marshlands. It is conducive to farmland irrigation, flooding regulation, adjustment of the local climate and self-purification of the water quality. Because of its benign functions, the native ecosystem of the lake is ecologically sound, and the thriving wildlife in its ecosystem makes it a primordial pool of biodiversity. Besides, it is possible to transform it into a national base for environmental education and an R&D center for freshwater organisms, so that it can play a constructive role in heightening the public's awareness of environmental protection.

  20. Glacial lakes in the Horgos river basin and their outbreak risk assessment

    OpenAIRE

    A. P. Medeu; T. G. Tokmagambetov; A. L. Kokarev; P. A. Plekhanov; N. S. Plekhanova

    2015-01-01

    The river Khorgos (in Kazakhstan – Korgas) is a boundary river between Kazakhstan and China. Its basin is located in the central part of southern slope of Dzhungarskiy (Zhetysu) Alatau range. According to agreement between Kazakhstan and China at the boundary transition of Khorgos in the floodplain of the river Khorgos the large Center of Frontier Cooperation is erected. Estimation of safety of the mentioned object including connection with possible glacial lakes outbursts has the importance ...

  1. Using integrated multivariate statistics to assess the hydrochemistry of surface water quality, Lake Taihu basin, China

    OpenAIRE

    Xiangyu Mu; James Brower; Donald I. Siegel; Anthony J. Fiorentino II; Shuqing An; Ying Cai; Delin Xu; Hao Jiang

    2014-01-01

    Natural factors and anthropogenic activities both contribute dissolved chemical loads to  lakes and streams.  Mineral solubility,  geomorphology of the drainage basin, source strengths and climate all contribute to concentrations and their variability. Urbanization and agriculture waste-water particularly lead to aquatic environmental degradation. Major contaminant sources and controls on water quality can be asssessed by analyzing the variability in proportions of major and minor solutes in ...

  2. Distribution, sources and ecological risk assessment of heavy metals in surface sediments from Lake Taihu, China

    Science.gov (United States)

    Yin, Hongbin; Gao, Yongnian; Fan, Chengxin

    2011-10-01

    The distribution, sources and ecological risk of heavy metals in surface sediments from Lake Taihu were studied. Results showed that the measured heavy metals had varied spatial distribution patterns, indicating that they had complex origins and controlling factors. Pearson's correlation analysis revealed that the total phosphorus and the loss on ignition were positively correlated with the measured metals except Cd. Principal component analysis and cluster analysis demonstrated that Hg, Cu, Cr, Cd and Pb might originate from domestic sewage and industrial wastewater, whereas As predominantly originated from natural processes. Potential ecological risk indices indicated that sediment from Wuli Lake, Gonghu Bay and the Northwest Area suffered high pollution, whereas other areas of Lake Taihu were moderately polluted. A comparison of metal levels with the effects range low (ERL) and effects range median (ERM) showed that metals exceeded their corresponding ERL limit at 13.6-72.3% (72.3% for As, 52.4% for Pb, 27.7% for Cu, 22.8% for Cd, 16.0 for Hg and 13.6% for Cr) of the sites investigated. Moreover, 3.90% and 0.50% of the sites sampled exceeded the ERM thresholds for Hg and Pb, respectively.

  3. Multi-Year Assessment of Toxic Genotypes and Microcystin Concentration in Northern Lake Taihu, China

    Science.gov (United States)

    Hu, Lili; Shan, Kun; Lin, Lizhou; Shen, Wei; Huang, Licheng; Gan, Nanqin; Song, Lirong

    2016-01-01

    Lake Taihu is the third-largest freshwater lake in China and has been suffering from cyanobacterial blooms for over two decades. The northern part of the lake, Meiliang Bay, is known to be at high risk of dense and sustained Microcystis blooms and toxins. This study aimed to investigate and record the annual and seasonal dynamics of toxic genotype, Microcystis morphospecies succession and microcystin variation. It also aimed to find out the underlying driving factors influencing the dynamic changes. Microcystin (MC) and the Microcystis genotype were quantified using HPLC and quantitative real-time PCR, respectively. Our study, over three consecutive years, showed that the pattern of morphospecies succession was seasonally distinct and annually consistent. During the same period in 2012, 2013 and 2014, the average MC were, on dry weight basis, 733 μg·g−1, 844 μg·g−1, 870 μg·g−1, respectively. The proportion of toxic Microcystis accounted for 41%, 44% and 52%, respectively. Cell bound microcystin was found to correlate with the percentage of toxic Microcystis. Based on historical and current data, we conclude that annual bloom toxicity was relatively stable or possibly increased over the last decade. PMID:26784229

  4. Distribution, sources and ecological risk assessment of heavy metals in surface sediments from Lake Taihu, China

    International Nuclear Information System (INIS)

    The distribution, sources and ecological risk of heavy metals in surface sediments from Lake Taihu were studied. Results showed that the measured heavy metals had varied spatial distribution patterns, indicating that they had complex origins and controlling factors. Pearson's correlation analysis revealed that the total phosphorus and the loss on ignition were positively correlated with the measured metals except Cd. Principal component analysis and cluster analysis demonstrated that Hg, Cu, Cr, Cd and Pb might originate from domestic sewage and industrial wastewater, whereas As predominantly originated from natural processes. Potential ecological risk indices indicated that sediment from Wuli Lake, Gonghu Bay and the Northwest Area suffered high pollution, whereas other areas of Lake Taihu were moderately polluted. A comparison of metal levels with the effects range low (ERL) and effects range median (ERM) showed that metals exceeded their corresponding ERL limit at 13.6–72.3% (72.3% for As, 52.4% for Pb, 27.7% for Cu, 22.8% for Cd, 16.0 for Hg and 13.6% for Cr) of the sites investigated. Moreover, 3.90% and 0.50% of the sites sampled exceeded the ERM thresholds for Hg and Pb, respectively.

  5. 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.

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

    International Nuclear Information System (INIS)

    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

  7. Accuracy of Self-Reported Breast Cancer Information among Women from the Ontario Site of the Breast Cancer Family Registry

    OpenAIRE

    Andriana Barisic; Gord Glendon; Nayana Weerasooriya; Andrulis, Irene L.; Knight, Julia A.

    2012-01-01

    Obtaining complete medical record information can be challenging and expensive in breast cancer studies. The current literature is limited with respect to the accuracy of self-report and factors that may influence this. We assessed the agreement between self-reported and medical record breast cancer information among women from the Ontario site of the Breast Cancer Family Registry. Women aged 20–69 years diagnosed with incident breast cancer 1996–1998 were identified from the Ontario Cancer R...

  8. Assessment methodology for new cooling lakes. Volume 2. Development of empirical multivariate relationships for evaluating fish communities in new cooling lakes. Final report

    International Nuclear Information System (INIS)

    Numerical classification techniques were used to define groups of lakes with distinct fish community attributes. Simple linear and multiple regression were then used to identify the important environmental variables affecting the fish communities. Next, the multivariate statistical technique of discriminant analysis was tested and shown to predict the groups of lakes (defined in the initial step of classification) using the identified environmental variables. Classification equations derived in the discriminant analysis enable the user to predict fish community characteristics of a new lake. The equations combine the information from nine limnological parameters into a single index of classification. Based on the value of this index, the lake is classified into one of four distinct groups. The fishery characteristics of the indicated group are then used to predict fish community structure and recreational fishery use. Angler-use estimates for the group are used to project multiple use benefits

  9. Ontario Hydro annual report, 1988

    International Nuclear Information System (INIS)

    Ontario continues a strong growth in electricity consumption; over the past five years consumption has risen an average of 5 percent a year. In 1988 consumption rose by 6.5 percent to 133.1 billion kilowatt-hours. Peak demand was 23 million kilowatts. The top priority for the 1990s will be improving the energy efficiency of customers and the operating efficiency of the Corporation, with a target saving of 4500 megawatts through demand management and energy efficiency by the year 2000. A new environmental division has been formed, as well as a division for non-utility generation. Safety is of particular importance to the Nuclear Generating Division; in all nuclear operations, after 143 million hours worked from 1955 to 1988, there has never been a work-related fatality or a detectable injury due to radiation. The average radiation dose per worker continues to decline and is now under 10 percent of the legal dose limit. Retubing of Pickering Nuclear Generating Station unit 2 has been completed. Retubing of unit 1 is under way, and work on units 3 and 4 has been approved. Construction continues on the Darlington Nuclear Generating Station, where the first unit is expected to go into service in 1989. The Darlington Tritium Removal Facility was completed

  10. Wind energy integration in Ontario

    International Nuclear Information System (INIS)

    This PowerPoint presentation discussed some of the issues that Ontario's Independent Electricity System Operator (IESO) must now consider in order to successfully integrate wind energy into the province's electricity grid. Wind energy is expected to form a significant portion of the province's projected electricity supply in the future. However, the variability of wind energy remains a challenge to system operators and can have an impact on system reliability. The variable generation capacity of wind and solar energy can cause ramping events. The ability to predict output from variable resources such as wind energy will be essential for maintaining market efficiency and system reliability. Direct telemetry and reporting technologies may be needed to ensure the reliability of large-scale embedded wind and solar generators. However, the integration of renewable energy into the electricity supply system will help to resolve issues related to surplus baseload generation. The IESO is continuing to define operating needs for the future while working with industry to develop new standards that ensure the reliable supply of electricity. tabs., figs.

  11. Assessing Li and other leachable geochemical proxies for paleo-salinity in lake sediments from the Mono Basin, CA (USA)

    Science.gov (United States)

    Sahajpal, Rahul; Zimmerman, Susan R. H.; Datta, Saugata; Hemming, N. Gary; Hemming, Sidney R.

    2011-12-01

    Regional climate-driven hydrological changes are accompanied by salinity changes in closed basin lakes. We have investigated acid leachable Li, along with other leachable ions including Mg, Ca and Sr, as geochemical proxies of salinity in lake sediments in the Mono Basin, California. All the elements in the acid leachable suite show a strong correlation with paleo-lake level estimates based on physical and stratigraphic evidence. The CaCO 3 content of lake sediments, which has been shown to be a reliable proxy for lake level changes in the Mono basin and the adjoining Owens Lake basin, corresponds well with our acid-leachable proxy data.

  12. Linking land use/land cover change to phosphorus and sediment runoff in the Great Lakes basins

    Science.gov (United States)

    Perry, C. H.; Nelson, M. D.; Garner, J. D.

    2015-12-01

    The Great Lakes Restoration Initiative (GLRI) is a multi-agency partnership supported by a multi-billion dollar investment by the US Environmental Protection Agency. One major focus outlined in the GLRI Action Plan is "reducing nutrient runoff that contributes to harmful/nuisance algal blooms." For the past several years, the USDA Forest Service has engaged in a comprehensive assessment of the character and trends of landscapes in watersheds draining into the Great Lakes as a means of prioritizing agency investments targeting nutrient and sediment reductions. Assessments in the Lake Superior and Lake Michigan basins utilized existing inventory collected by the Forest Service, and landscape trends were extracted by processing Landsat Time Series Stacks (LTSS) using the methods outlined by Stueve et al. (2011) and validated according to the process described by Zimmerman et al. (2013). These data were combined with ancillary datasets and documented the link between land use and water quality in the Lake Superior and Lake Michigan basins (see Seilheimer et al. 2013). While the resulting models were useful at prioritizing investments in basins with water quality observations, the greater benefit was prioritizing investments in landscapes lacking water quality measurements. Having demonstrated the linkage between land and water quality in the western basins, we are now completing similar prioritizations of the eastern Great Lakes (Lakes Huron, Erie, and Ontario). The process is largely similar, but we are implementing the Forest Service's novel Landscape Change Monitoring System to process the LTSS. This new approach offers improved estimates of land use and land cover change, noticeably reducing errors of both commission and omission. Taken together with existing ancillary data, we expect the linkages between land use and water quality to be even stronger, and the prioritizations of ungaged basins to be even more robust.

  13. A Multi-Parameter Approach to Assessing the Origin of Sediment-Magnetic Signatures in Small, Temperate-Climate Lakes

    Science.gov (United States)

    Lascu, I.; Plank, C.; Banerjee, S. K.; Ito, E.

    2008-12-01

    To assess the controls on sedimentary magnetic signatures in lakes, we analyzed the characteristics of core, surface, sediment trap, and catchment samples collected from small, temperate-climate lakes, which are commonly used in paleoenvironmental reconstructions. Magnetic properties of sediments were evaluated using room temperature measurements (susceptibility, IRM, ARM), hysteresis parameters, low temperature magnetization curves, and modeling of bulk coercivity spectra, obtained from IRM and ARM acquisition and demagnetization curves. The results highlight several characteristics of lacustrine sediments: 1) Magnetic- mineral assemblages are dominated by low-coercivity minerals (e.g. magnetite); 2) Saturation magnetization, rather than remanent magnetization, is a better overall indicator of concentration, due to differences in grain size; 3) Shoreline samples contain almost exclusively detrital multi-domain (MD) magnetite grains, while littoral and profundal sediments contain a mixture of MD and in-lake produced single-domain (SD) grains; 4) Profundal sediments, deposited in seasonally-anoxic waters, exhibit dissolution of finer-grained particles; 5) Calculated contributions of a biogenic source differ depending on method utilized. ARM/IRM ratios and delta/delta ratios are more conservative in this aspect, indicating a maximum of 50% contribution of biogenic magnetite. Hysteresis and coercivity analyses yield up to 75% contribution of biogenic particles; 6) There is a direct linear relation between percent mass organic matter (OM) and ARM/IRM, showing a dependence of magnetic grain size on organic carbon concentration. This correlation highlights the role OM has in the process of production and preservation of magnetosomes. Organic matter decomposition depletes the dissolved oxygen and leads to temporary or permanent anoxic conditions in the sediment. If conditions are suboxic (e.g. in the littoral zone, where oxygen can diffuse into the sediment from the

  14. ASSESSMENT OF THE ECONOMIC AND ENVIRONMENTAL SUITABILITY OF THE JIU-CORABIA ENCLOSURE FOR LAKE USAGE USING GIS TECHNIQUES

    Directory of Open Access Journals (Sweden)

    Denisa Mariana DAN

    2016-08-01

    Full Text Available One of the three strategic objectives of the Europe 2020 Agenda is to ensure the sustainable management of the natural resources and to fight against climate changes. Considering water to be not only a valuable natural resource for any type of landscape, but also the vital environmental component that ensured a minimum of productivity for the people working the unproductive salinization and gleyzation affected soils in the Jiu-Corabia enclosure, using embankment dams to breake the link between the Danube and the flood organism it created over a timespan of millenia has proven in the last 50 years to be an economic and ecological failure. Since the December 1989 events in Romania, after most of the socialist institutions have proven to be too resource consuming, thus unprofitable or maladaptive, the Jiu-Corabia locals have individually experimented with various land cultivation patterns, all of them based on draught-resistant crops, such as peanuts. In spite of it being the original natural landuse, lake usage has only been scarcely mentioned as a project after the 2006 flood, but after being institutionally rejected, its benefits in terms of ecological restoration, financial productivity have not been further looked into. The current article aims to identify different height level scenarios of lake usage in the Jiu-Corabia enclosure, using GIS technique. Lake volumes are calculated for each scenario with the aim of assessing the volume of water this enclose can absorb during flooding periods, as well as of estimating fish production for when the waters are low and it is not needed as a controlled flood chamber. Other benefits, such as providing a source of humidity for precipitations which will aid the crops nearby, have not been monetized, but contribute to the regional development efforts.

  15. The effect of the Ontario Bariatric Network on health services utilization after bariatric surgery: a retrospective cohort study

    Science.gov (United States)

    Elnahas, Ahmad; Jackson, Timothy D.; Okrainec, Allan; Austin, Peter C.; Bell, Chaim M.; Urbach, David R.

    2016-01-01

    Background: In 2009, the Ontario Bariatric Network was established to address the exploding demand by Ontario residents for bariatric surgery services outside Canada. We compared the use of postoperative hospital services between out-of-country surgery recipients and patients within the Ontario Bariatric Network. Methods: We conducted a population-based, comparative study using administrative data held at the Institute for Clinical Evaluative Sciences. We included Ontario residents who underwent bariatric surgery between 2007 and 2012 either outside the country or at one of the Ontario Bariatric Network's designated centres of excellence. The primary outcome was use of hospital services in Ontario within 1 year after surgery. Results: A total of 4852 patients received bariatric surgery out of country, and 5179 patients underwent surgery through the Ontario Bariatric Network. After adjustment, surgery at a network centre was associated with a significantly lower utilization rate of postoperative hospital services than surgery out of country (rate ratio 0.90, 95% confidence interval [CI] 0.84 to 0.97). No statistically significant differences were found with respect to time in critical care or mortality. However, the physician assessment and reoperation rates were significantly higher among patients who received surgery at a network centre than among those who had bariatric surgery out of country (rate ratio 4.10, 95% CI 3.69 to 4.56, and rate ratio 1.84, 95% CI 1.34 to 2.53, respectively). Interpretation: The implementation of a comprehensive, multidisciplinary provincial program to replace outsourcing of bariatric surgical services was associated with less use of postoperative hospital services by Ontario residents undergoing bariatric surgery. Future research should include an economic evaluation to determine the costs and benefits of the Ontario Bariatric Network. PMID:27730113

  16. Progress towards the experimental reintroduction of woodland caribou to Minnesota and adjacent Ontario

    Directory of Open Access Journals (Sweden)

    Peter A. Jordan

    1998-03-01

    Full Text Available Woodland caribou (Rangifer tarandus caribou are native to Minnesota but started to decline in the mid 1800s and disappeared from the state by 1940. Their demise had been attributed to extensive timber harvest and ovethunting; but more recently mortality from the meningeal worm, Parelaphostrongylus tenuis, carried by white-tailed deer (Odocoileus virginianus, and increased prédation by timber wolves (Canis lupus and black bears (Ursus americanus have been suggested as additional causes. We describe a current initiative to explore feasibility of restoring caribou to the boundary waters region of Minnesota and Ontario. Feasibility studies have been conducted under the guidance of the North Central Catibou Corporation (NCCC, a non-governmental organization with representation from relevant state, federal, Native American, and Canadian agencies. Results indicate a Within Minnesota the most suitable site for woodland caribou lies within the eastern sector of the Boundary Waters Canoe Area Wilderness (BWCAW, and this is contiguous with a similarly suitable sector of Ontario's Quetico Provincial Park: Together these comprise the recommended 1300-km2 Boundary Waters Caribou Region (BWCR; b Vegetation in the BWCR has changed little since the 1920s when caribou were last present other than effects of fire suppression; c Level of white-tailed deer, hence the meningeal worm, is so low in the BWCR that this factor is unlikely to impede survival of re-introduced caribou; d While wolf numbers within the wider region are relatively high, their impacts may be minimized if caribou are released in small, widely scattered groups; in addition, an abundance of lakes with islands affords good summer-time prédation security; e Threat to calves from black bears, probably more numerous than in earlier times, appears lessened by the security of lakeshores and islands; and f A simulation model, combining knowledge from elsewhere with the BWCR assessment, suggests that

  17. Delineating demographic units of woodland caribou (Rangifer tarandus caribou in Ontario: cautions and insights

    Directory of Open Access Journals (Sweden)

    Jennifer L. Shuter

    2012-03-01

    Full Text Available Delineating demographic structure across an organism’s range can reveal the extent to which population dynamics in different geographic areas are driven by local or external factors and can be crucial for effective conservation and management. Obtaining optimal data for such analyses can be time and resource-intensive and impending development and resource extraction pressures may necessitate the examination of existing data, even when they are less than ideal. We analyzed a historic telemetry dataset containing satellite radio-collar locations of 73 forest-dwelling woodland caribou in northern Ontario to determine demographic structure. We applied several clustering methods (i.e., agglomerative, divisive and fuzzy k-means to median seasonal locations. Results were used to distinguish demographic units and minimum convex polygons and fixed-kernel density estimates were used to delineate unit boundaries and core areas. For areas where sampling was considered representative of the distribution of caribou on the landscape, we assessed demographic distinctness by evaluating intra-individual variation in cluster membership, membership strength and distance between boundaries and core areas of adjacent units. The number and composition of clusters identified was similar among methods and caribou were grouped into 6 general clusters. The distinctions between the three clusters identified in the central portion of the province (i.e., Lac Seul, Wabakimi, Geraldton and the two clusters identified in the eastern portion of the province (i.e., Cochrane and Cochrane-Quebec were determined to represent demographic structuring. Additional distinctions in other areas (i.e., between The Red Lake and Lac Seul clusters in the west and between the central and eastern clusters may just be artifacts of the original sampling effort. Amongst demographic units, there was no evidence of individual flexibility in cluster membership and average membership strength was

  18. A model assessment of the ability of lake water in Terra Nova Bay, Antarctica, to induce the photochemical degradation of emerging contaminants.

    Science.gov (United States)

    Minella, Marco; Maurino, Valter; Minero, Claudio; Vione, Davide

    2016-11-01

    The shallow lakes located in Terra Nova Bay, Antarctica, are free from ice for only up to a couple of months (mid December to early/mid February) during the austral summer. In the rest of the year, the ice cover shields the light and inhibits the photochemical processes in the water columns. Previous work has shown that chromophoric dissolved organic matter (CDOM) in these lakes is very reactive photochemically. A model assessment is here provided of lake-water photoreactivity in field conditions, based on experimental data of lake water absorption spectra, chemistry and photochemistry obtained previously, taking into account the water depth and the irradiation conditions of the Antarctic summer. The chosen sample contaminants were the solar filter benzophenone-3 and the antimicrobial agent triclosan, which have very well known photoreactivity and have been found in a variety of environmental matrices in the Antarctic continent. The two compounds would have a half-life time of just a few days or less in the lake water during the Antarctic summertime, largely due to reaction with CDOM triplet states ((3)CDOM*). In general, pollutants that occur in the ice and could be released to lake water upon ice melting (around or soon after the December solstice) would be quickly photodegraded if they undergo fast reaction with (3)CDOM*. With some compounds, the important (3)CDOM* reactions might favour the production of harmful secondary pollutants, such as 2,8-dichlorodibenzodioxin from the basic (anionic) form of triclosan.

  19. A model assessment of the ability of lake water in Terra Nova Bay, Antarctica, to induce the photochemical degradation of emerging contaminants.

    Science.gov (United States)

    Minella, Marco; Maurino, Valter; Minero, Claudio; Vione, Davide

    2016-11-01

    The shallow lakes located in Terra Nova Bay, Antarctica, are free from ice for only up to a couple of months (mid December to early/mid February) during the austral summer. In the rest of the year, the ice cover shields the light and inhibits the photochemical processes in the water columns. Previous work has shown that chromophoric dissolved organic matter (CDOM) in these lakes is very reactive photochemically. A model assessment is here provided of lake-water photoreactivity in field conditions, based on experimental data of lake water absorption spectra, chemistry and photochemistry obtained previously, taking into account the water depth and the irradiation conditions of the Antarctic summer. The chosen sample contaminants were the solar filter benzophenone-3 and the antimicrobial agent triclosan, which have very well known photoreactivity and have been found in a variety of environmental matrices in the Antarctic continent. The two compounds would have a half-life time of just a few days or less in the lake water during the Antarctic summertime, largely due to reaction with CDOM triplet states ((3)CDOM*). In general, pollutants that occur in the ice and could be released to lake water upon ice melting (around or soon after the December solstice) would be quickly photodegraded if they undergo fast reaction with (3)CDOM*. With some compounds, the important (3)CDOM* reactions might favour the production of harmful secondary pollutants, such as 2,8-dichlorodibenzodioxin from the basic (anionic) form of triclosan. PMID:27487093

  20. 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, Randy; 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.