Review of Reports on Lake Erie - Lake Ontario Waterway, New York. Appendix D. Economics.

Science.gov (United States)

1973-10-01

Venezuela (29 percent). Canada produced 48.3 million tons of iron ore in 1970 ,of which 23.9 million tons were exported to the United States (14.4 million...grain traffic, 1971 D-14 D-6 U.S. - Great Lakes grain exports 1960 - 1971 and projected D-15 D-7 U.S. doal traffic, Lake Erie - Lake Ontario, 1958-1970...Soybeans Wheat Barley Oats Rice Sorghum Grains Flaxseed Oilseeds, n.e.c. Tobacco, leaf Hay and Fodder Field crops, n.e.c. Fresh fruits Co ffee Cocoa beans

Lake Ontario: Food web dynamics in a changing ecosystem (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.

2003-01-01

We examined stressors that have led to profound ecological changes in the Lake Ontario ecosystem and its fish community since 1970. The most notable changes have been reductions in phosphorus loading, invasion by Dreissena spp., fisheries management through stocking of exotic salmonids and control of sea lamprey (Petromyzon marinus), and fish harvest by anglers and double-crested cormorants (Phalacrocorax auritus). The response to these stressors has led to (i) declines in both algal photosynthesis and epilimnetic zooplankton production, (ii) decreases in alewife (Alosa pseudoharengus) abundance, (iii) declines in native Diporeia and lake whitefish (Coregonus clupeaformis), (iv) behavioral shifts in alewife spatial distribution benefitting native lake trout (Salvelinus namaycush), threespine stickleback (Gasterosteus aculeatus), and emerald shiner (Notropis atherinoides) populations, (v) dramatic increases in water clarity, (vi) predation impacts by cormorants on select fish species, and (vii) lake trout recruitment bottlenecks associated with alewife-induced thiamine deficiency. We expect stressor responses associated with anthropogenic forces like exotic species invasions and global climate warming to continue to impact the Lake Ontario ecosystem in the future and recommend continuous long-term ecological studies to enhance scientific understanding and management of this important resource.

Scale and watershed features determine lake chemistry patterns across physiographic regions in the far north of Ontario, Canada

Directory of Open Access Journals (Sweden)

Josef MacLeod

2016-11-01

Full Text Available Changes in the far north of Ontario (>50°N latitude, like climate warming and increased industrial development, will have direct effects on watershed characteristics and lakes. To better understand the nature of remote northern lakes that span the Canadian Shield and Hudson Bay Lowlands, and to address the pressing need for limnological data for this vast, little-studied area of Ontario, lake chemistry surveys were conducted during 2011-2012. Lakes at the transition between these physiographic regions displayed highly variable water chemistry, reflecting the peatland landscape with a mix of bog and fen watersheds, and variations in the extent of permafrost. In the transition area, Shield and Lowlands lakes could not be clearly differentiated based on water chemistry; peat cover decouples, to varying degrees, the lakes from the influences of bedrock and surficial deposits. Regional chemistry differences were apparent across a much broader area of northern Ontario, due to large-scale spatial changes in geology and in the extent of peatlands and permafrost.  Shield lakes in the far northwest of Ontario had Ca, Mg, and TP concentrations markedly higher than those of many Lowlands lakes and previously studied Shield lakes south of 50°N, related to an abundance of lacustrine and glacial end-moraine deposits in the north.

Confirmation of cisco spawning in Chaumont Bay, Lake Ontario using an egg pumping device

Science.gov (United States)

George, Ellen M.; Stott, Wendylee; Young, Brian; Karboski, Curtis T.; Crabtree, Darran L.; Roseman, Edward; Rudstam, Lars G.

2017-01-01

Cisco Coregonus artedi, a historically abundant and commercially important fish in the Great Lakes, have declined drastically in the last century due to the impacts of invasive species, overfishing, and habitat degradation. Chaumont Bay, New York is believed to contain one of the last remaining spawning populations of cisco in Lake Ontario although direct evidence of spawning has remained elusive. We document cisco spawning in Chaumont Bay for the first time in decades through the use of an egg pumping device specifically developed to sample through lake ice. Forty-one eggs were identified as cisco using genetic barcoding of the mitochondrial cytochrome c oxidase I (COI) gene. Cisco eggs were associated with shallow, rocky shoals. Contemporary knowledge of spawning behavior is an important step toward the successful restoration of cisco in Lake Ontario and across the Great Lakes.

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

Geochemical distribution of trace metals and organochlorine contaminants of a lake ontario shoreline marsh

Energy Technology Data Exchange (ETDEWEB)

Glooschenko, W A; Capocianco, J; Coburn, J; Glooschenko, V

1981-02-01

Rattray Marsh, an 8 ha marsh on the Lake Ontario shoreline at Mississauga, Ontario, is an important local habitat for waterfowl and shorebirds during spring and fall migration. A study was conducted to determine the distribution of nutrients (carbon, nitrogen, and phosphorus) and potential trace metal and organochlorine pollutants in the marsh as evidenced by the sedimentary concentrations of these compounds. Generally, copper, zinc, lead, and mercury were higher in concentration in local soils than in Lake Ontario sediments. Metals and organic carbon levels did not correlate, and the metals appeared to be associated with silts and clays. Organochlorine contaminants include p,p1-DDE, p,p1-DDD, p,p1-DDT, alpha-chlordane, PCB, mirex, and HCB.

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.

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

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

Hypothesis carbon flow through the deepwater Lake Ontario foodweb

International Nuclear Information System (INIS)

Flint, R.W.

1986-01-01

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

Is reduced benthic flux related to the Diporeia decline? Analysis of spring blooms and whiting events in Lake Ontario

Science.gov (United States)

Watkins, James M.; Rudstam, Lars G.; Crabtree, Darran L.; Walsh, Maureen

2013-01-01

Benthic monitoring by USGS off the southern shore of Lake Ontario from October 1993 to October 1995 provides a detailed view of the early stages of the decline of the native amphipod Diporeia. A loss of the 1994 and 1995 year classes of Diporeia preceded the disappearance of the native amphipod at sites near Oswego and Rochester at depths from 55 to 130 m. In succeeding years, Diporeia populations continued to decline in Lake Ontario and were nearly extirpated by 2008. Explanations for Diporeia 's decline in the Great Lakes include several hypotheses often linked to the introduction and expansion of exotic zebra and quagga mussels (Dreissena sp.). We compare the timeline of the Diporeia decline in Lake Ontario with trends in two sources of organic matter to the sediments — spring diatom blooms and late summer whiting events. The 1994–95 decline of Diporeia coincided with localized dreissenid effects on phytoplankton in the nearshore and a year (April 1994 to May 1995) of decreased flux of organic carbon recorded by sediment traps moored offshore of Oswego. Later declines of profundal (> 90 m) Diporeia populations in 2003 were poorly associated with trends in spring algal blooms and late summer whiting events. Lake Ontario/Diporeia/Dreissena/remote sensing.

Shifts in the diets of slimy sculpin (Cottus cognatus) and lake whitefish (Coregonus clupeaformis) in Lake Ontario following the collapse of the burrowing amphipod Diporeia

Science.gov (United States)

Owens, Randall W.; Dittman, Dawn E.

2003-01-01

In Lake Ontario, the diets of slimy sculpin Cottus cognatus and lake whitefish Coregonus clupeaformis shifted from a diet dominated by the burrowing amphipod, Diporeia, and to a lesser extent, Mysis, to a more diverse diet, after Diporeia collapsed, to one dominated by Mysis and prey that were formerly less important or uncommon such as Chironomidae, Oligochaeta, and Ostracoda. Additionally, lake whitefish still preyed on native mollusks like Sphaeriidae and Gastropoda, but also preyed on exotic mollusks, Dreissena spp., which are swallowed intact and subsequently crushed in its muscular stomach. Whether Diporeia was abundant (1992) or scarce (1999), selection indices for Diporeia by slimy sculpins was positive, suggesting that Diporeia was a preferred prey. Unlike lake whitefish, slimy sculpins avoided Dreissena; therefore, energy diverted to Dreissena production was a real loss for slimy sculpins. The shifts in the diet of these benthic fishes corresponded with drastic changes in the benthic community between 1992 and 1999. The collapse of Diporeia, formerly the most abundant macroinvertebrate in the benthic community, along with sharp declines in the abundance of Oligochaeta and Sphaeriidae, coincided with the establishment and rapid expansion of Dreissena bugensis, the quagga mussel, and to a lesser degree Dreissena polymorpha, the zebra mussel. It appears that the Diporeia population first collapsed at depths >70 m in southeastern Lake Ontario by autumn 1992, at shallower depths in the eastern Lake Ontario by 1995, and along the entire south shore line at depths 100 m by 1999. In response to the disappearance of Diporeia, populations of two native benthivores, slimy sculpin and lake whitefish, collapsed in eastern Lake Ontario, perhaps due in part to starvation, because Diporeia was their principal prey. Presently, alternative food resources do not appear sufficient to sustain these two benthivores at their former levels of abundance. We do not expect slimy

137Cs radioactive dating of Lake Ontario sediment cores

International Nuclear Information System (INIS)

Ward, T.E.; Breeden, J.; Komisarcik, K.; Porter, R.; Czuczwa, J.; Kaminski, R.; McVeety, B.D.

1987-12-01

The distribution of 137 Cs in sediment cores from Lake Ontario provides estimates of the sediment accumulation rates. Geochronology with 210 Pb dating and distribution of Ambrosia (ragweed) pollen compare well with 137 Cs dating. These methods can determine with precision, changes in sedimentation occurring over the past 100 years or so. Typical sedimentation rates of 0.18-0.36 cm/yr were measured. 16 refs., 3 figs., 2 tabs

Seasonal variation in mercury and food web biomagnification in Lake Ontario, Canada

International Nuclear Information System (INIS)

Zhang Liang; Campbell, Linda M.; Johnson, Timothy B.

2012-01-01

Seasonal variation in mercury (Hg) concentrations and food web structure was assessed for eastern Lake Ontario. Hg concentrations, measured in 6 species of invertebrates and 8 species of fishes, tended to be highest in the spring and lowest in the summer for most biota. Yellow perch (Perca flavescens) exhibited significant ontogenetic shifts in diet and Hg, although such patterns were not evident for other species. Food web structure, as indicated by stable isotope values (δ 15 N, δ 13 C) was not static. Log-transformed Hg data were strongly and consistently correlated with δ 15 N values for the whole food web in each of the three seasons (slopes, 0.17–0.24) and across the entire year (slope, 0.2). While significantly different between seasons, the regression slope values are still consistent with published global Hg biomagnification rates. Our results indicate that the assessment of Hg trends in Great Lakes must take into account seasonal patterns and time of sampling. - Graphical abstract: Total mercury concentrations and trophic level (δ 15 N) regressions for organisms from the littoral Lake Ontario food web of Waupoos in 2009. Filled circles represent invertebrates while open circles represent fish. Dashed lines represents the regression between δ 15 N and THg of “whole” food web (log-Hg-δ 15 N regression equations in the upper left hand corner in each plot), and solid lines represents the regression between δ 15 N and THg of “fish-only” food web (log-Hg-δ 15 N regression equations in the lower right hand corner of each plot). Note that the y-axis is untransformed Hg concentrations plotted along a logarithmic scale, while the equations are based on log-transformed Hg values. Highlights: ► Most fish in littoral Lake Ontario had higher Hg concentrations in spring and lower Hg in summer. ► Log Hg consistently biomagnified throughout the food web in each season and for the year. ► Biomagnification rates (e.g., log Hg-δ 15 N slopes) vary

Dynamics of turbidity plumes in Lake Ontario. [Welland Canal and Niagara, Genesee, and Oswego Rivers

Science.gov (United States)

Pluhowski, E. J. (Principal Investigator)

1975-01-01

The author has identified the following significant results. Large turbidity features along the 275 km south shore of Lake Ontario were analyzed using LANDSAT-1 images. The Niagara River plume, ranging from 30 to 500 sq km in area is, by far, the largest turbidity feature in the lake. Based on image tonal comparisons, turbidity in the Welland Canal is usually higher than that in any other water course discharging into the lake during the shipping season. Less turbid water enters the lake from the Port Dalhousie diversion channel and the Genesee River. Relatively clear water resulting from the deposition of suspended matter in numerous upstream lakes is discharged by the Niagara and Oswego Rivers. Plume analysis corroborates the presence of a prevailing eastward flowing longshore current along the entire south shore. Plumes resulting from beach erosion were detected in the images. Extensive areas of the south shore are subject to erosion but the most severely affected beaches are situated between Fifty Mile Point, Ontario and Thirty Mile Point, New York along the Rochester embayment, and between Sodus Bay and Nine Mile Point.

Investigating Summer Thermal Stratification in Lake Ontario

Science.gov (United States)

James, S. C.; Arifin, R. R.; Craig, P. M.; Hamlet, A. F.

2017-12-01

Seasonal temperature variations establish strong vertical density gradients (thermoclines) between the epilimnion and hypolimnion. Accurate simulation of vertical mixing and seasonal stratification of large lakes is a crucial element of the thermodynamic coupling between lakes and the atmosphere in integrated models. Time-varying thermal stratification patterns can be accurately simulated with the versatile Environmental Fluid Dynamics Code (EFDC). Lake Ontario bathymetry was interpolated onto a 2-km-resolution curvilinear grid with vertical layering using a new approach in EFDC+, the so-called "sigma-zed" coordinate system which allows the number of vertical layers to be varied based on water depth. Inflow from the Niagara River and outflow to the St. Lawrence River in conjunction with hourly meteorological data from seven local weather stations plus three-hourly data from the North American Regional Reanalysis govern the hydrodynamic and thermodynamic responses of the Lake. EFDC+'s evaporation algorithm was updated to more accurately simulate net surface heat fluxes. A new vertical mixing scheme from Vinçon-Leite that implements different eddy diffusivity formulations above and below the thermocline was compared to results from the original Mellor-Yamada vertical mixing scheme. The model was calibrated by adjusting solar-radiation absorption coefficients in addition to background horizontal and vertical mixing parameters. Model skill was evaluated by comparing measured and simulated vertical temperature profiles at shallow (20 m) and deep (180 m) locations on the Lake. These model improvements, especially the new sigma-zed vertical discretization, accurately capture thermal-stratification patterns with low root-mean-squared errors when using the Vinçon-Leite vertical mixing scheme.

Improving regional climate and hydrological forecasting following the record setting flooding across the Lake Ontario - St. Lawrence River system

Science.gov (United States)

Gronewold, A.; Seglenieks, F.; Bruxer, J.; Fortin, V.; Noel, J.

2017-12-01

In the spring of 2017, water levels across Lake Ontario and the upper St. Lawrence River exceeded record high levels, leading to widespread flooding, damage to property, and controversy over regional dam operating protocols. Only a few years earlier, water levels on Lakes Superior, Michigan, and Huron (upstream of Lake Ontario) had dropped to record low levels leading to speculation that either anthropogenic controls or climate change were leading to chronic water loss from the Great Lakes. The contrast between low water level conditions across Earth's largest lake system from the late 1990s through 2013, and the rapid rise prior to the flooding in early 2017, underscores the challenges of quantifying and forecasting hydrologic impacts of rising regional air and water temperatures (and associated changes in lake evaporation) and persistent increases in long-term precipitation. Here, we assess the hydrologic conditions leading to the recent record flooding across the Lake Ontario - St. Lawrence River system, with a particular emphasis on understanding the extent to which those conditions were consistent with observed and anticipated changes in historical and future climate, and the extent to which those conditions could have been anticipated through improvements in seasonal climate outlooks and hydrological forecasts.

Constraints and motivations related to fishing along the Lake Ontario coast

Science.gov (United States)

Matthew P. Brincka; Diane M. Kuehn; Valerie Luzadis

2012-01-01

The number of nonresident anglers along the Lake Ontario coast has decreased over the past 15 years. Therefore, in order to sustain a strong sport fishing industry, local businesses and tourism promoters might want to tap into the large resident angler market group. This study examines resident anglers' social, environmental, and economic constraints/facilitators...

Status of rainbow smelt in the U.S. waters of Lake Ontario, 2013

Science.gov (United States)

Weidel, Brian C.; Connerton, Michael J.

2014-01-01

Rainbow Smelt Osmerus mordax are the second most abundant pelagic prey fish in Lake Ontario after Alewife Alosa psuedoharengus. The 2013, USGS/NYSDEC bottom trawl assessment indicated the abundance of Lake Ontario age-1 and older Rainbow Smelt decreased by 69% relative to 2012. Length frequency-based age analysis indicated that age-1 Rainbow Smelt constituted approximately 50% of the population, which is similar to recent trends where the proportion of age-1 has ranged from 95% to 42% of the population. While they constituted approximately half of the catch, the overall abundance index for age 1 was one of the lowest observed in the time series, potentially a result of cannibalism from the previous year class. Combined data from all bottom trawl assessments along the southern shore and eastern basin indicate the proportion of the fish community that is Rainbow Smelt has declined over the past 30 years. In 2013 the proportion of the pelagic fish catch (only pelagic species) that was Rainbow Smelt was the second lowest in the time series at 3.1%. Community diversity indices, based on bottom trawl catches, indicate that Lake Ontario fish community diversity, as assessed by bottom trawls, has sharply declined over the past 36 years and in 2013 the index was the lowest value in the time series. Much of this community diversity decline is driven by changes in the pelagic fish community and dominance of Alewife.

Sanctuaries for lake trout in the Great Lakes

Science.gov (United States)

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

1987-01-01

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

Ground-water availability in the eastern part of the Lake Ontario Basin, New York

Science.gov (United States)

Miller, Todd S.

1986-01-01

A set of three maps show surficial geology, significant unconsolidated aquifers and well yield, and selected well locations for the Lake Ontario basin, New York. In the low areas , glaciers and wave action of former high-level lakes deposited permeable sand and gravel to form aquifers that yield more than 10 gal/min of water to wells. Small quantities of water (less than 2 gal/min) can be pumped from dug wells that top till and fine lake-sediment deposits. (USGS)

Lake trout demographics in relation to burbot and coregonine populations in the Algonquin Highlands, Ontario

Science.gov (United States)

Carl, L.M.

2008-01-01

The objective of the study was to test the hypothesis that lake trout populations change in relation to cisco, lake whitefish, round whitefish and burbot populations in lakes in the Algonquin Highlands region of Ontario. Lake trout population change is greatest where cisco and lake whitefish are present. Lake trout populations in lakes without either coregonine tend to have small adults and many juveniles. Where cisco or lake whitefish are present, adult lake trout are large, juvenile abundance is low, and the stock-recruit relationship appears to be uncoupled likely due to a larval bottleneck. Lake trout populations in these lakes may be sensitive to overfishing and recruitment failure. Lake trout populations do not appear to change in relation to round whitefish. There appears to be an indirect positive change on juvenile lake trout abundance through reductions in the density of benthic coregonines in the presence of large, hypolimnetic burbot. ?? 2007 Springer Science+Business Media B.V.

The distribution and abundance of gamma emitting radionuclides in Lake Ontario sediments

International Nuclear Information System (INIS)

McKinley, R.S.

1985-03-01

The distribution of gamma emitting radionuclides in Lake Ontario sediments was investigated. Samples were collected using a systematic design in the vicinity of Pickering and Darlington, and supplemented by lakewide offshore samples. Naturally occurring 40 K was the predominant source of gamma activity. 60 Co was the only potentially CANDU released radionuclide which showed a distributional association with the Pickering 'A' NGS discharge

Lake sediments as natural seismographs: Earthquake-related deformations (seismites) in central Canadian lakes

Science.gov (United States)

Doughty, M.; Eyles, N.; Eyles, C. H.; Wallace, K.; Boyce, J. I.

2014-11-01

Central Canada experiences numerous intraplate earthquakes but their recurrence and source areas remain obscure due to shortness of the instrumental and historic records. Unconsolidated fine-grained sediments in lake basins are 'natural seismographs' with the potential to record ancient earthquakes during the last 10,000 years since the retreat of the Laurentide Ice Sheet. Many lake basins are cut into bedrock and are structurally-controlled by the same Precambrian basement structures (shear zones, terrane boundaries and other lineaments) implicated as the source of ongoing mid-plate earthquake activity. A regional seismic sub-bottom profiling of lakes Gull, Muskoka, Joseph, Rousseau, Ontario, Wanapitei, Fairbanks, Vermilion, Nipissing, Georgian Bay, Mazinaw, Simcoe, Timiskaming, Kipawa, Parry Sound and Lake of Bays, encompassing a total of more than 2000 kilometres of high-resolution track line data supplemented by multibeam and sidescan sonar survey records show a consistent sub-bottom stratigraphy of relatively-thick lowermost lateglacial facies composed of interbedded semi-transparent mass flow facies (debrites, slumps) and rhythmically-laminated silty-clays. Mass flows together with cratered ('kettled') lake floors and associated deformations reflect a dynamic ice-contact glaciolacustrine environment. Exceptionally thick mass flow successions in Lake Timiskaming along the floor of the Timiskaming Graben within the seismically-active Western Quebec Seismic Zone (WQSZ), point to a higher frequency of earthquakes and slope failure during deglaciation and rapid glacio-isostatic rebound though faulting continues into the postglacial. Lateglacial faulting, diapiric deformation and slumping of coeval lateglacial sediments is observed in Parry Sound, Lake Muskoka and Lake Joseph, which are all located above prominent Precambrian terrane boundaries. Lateglacial sediments are sharply overlain by relatively-thin rhythmically-laminated and often semi

Correlates of mercury in fish from lakes near Clyde Forks, Ontario, Canada

International Nuclear Information System (INIS)

Ethier, A.L.M.; Scheuhammer, A.M.; Bond, D.E.

2008-01-01

Subsurface soils near Clyde Forks, Ontario, Canada, can have naturally high concentrations of mercury (Hg) from local geological sources. To investigate Hg in local aquatic food webs, Hg was measured in fish dorsal muscle (mainly yellow perch [YP] and pumpkinseed sunfish [PS]) and surface sediments from 10 regional lakes. Water chemistry, along with fork length, weight, and stable isotopes (δ 15 N, δ 13 C, δ 34 S) in fish were also measured. No lake sediments had elevated (>0.3 μg/g dw) Hg, and average Hg concentrations in fish were not sufficiently high ( 13 C), and certain lake variables (e.g., pH for YP). PS with more pelagic feeding habits had higher δ 34 S and Hg than those with more littoral feeding habits. Potential biological linkages between fish Hg and δ 34 S, a parameter that may be related to the lake sulphate-reducing bacteria activity, requires further investigation. - Fish from lakes near a localized geological Hg source do not have elevated Hg concentrations

Seismicity and seismotectonics of the Western Lake Ontario Region -relocation of the seismic events phase III

International Nuclear Information System (INIS)

Mohajer, A.A.

1995-12-01

Earthquake hazard analysis in Canada relies mainly on recorded earthquake data. The ability to record earthquakes of a given magnitude has varied considerably over time as has the accuracy of location determinations. Recomputation of earthquake locations has been suggested as a possible means of improving the existing data base for better definition of seismic sources. In this study, the locations of more than 50 small to moderate magnitude earthquakes (M≤5), in the western Lake Ontario region, were examined. Available seismograph records in the Record Centre of the National Archives of Canada were examined for events that occurred prior to 1978. The events recorded after this date showed increasing accuracy in their location determinations due to initiation and improvements of the Eastern Canada Telemetry Network (ECTN). Data compiled from the study are based on the relocated and/or selected events with the minimum travel time residuals at the Canadian and American stations. Except for a few scattered events in the south-central part of the Lake Ontario region, microearthquakes (M<3.5) cluster along or at the intersection of prominent aeromagnetic and gravity anomalies, within the Toronto-Hamilton Seismic Zone. This is indicative of certain seismotectonic relationships in this region. The depth distribution or the better located events show that a range of 5 to 20 km is dominant and, therefore, they are not near-surface stress relief phenomena. However, details of the structural manifestation of inferred seismogenic features need further ground truthing, backed by long term seismic monitoring. (author) 66 refs., 3 tabs., 6 figs

Comparison of genetic and visual identification of cisco and lake whitefish larvae from Chaumont Bay, Lake Ontario

Science.gov (United States)

George, Ellen M.; Hare, Matthew P.; Crabtree, Darran L.; Lantry, Brian F.; Rudstam, Lars G.

2017-01-01

Cisco Coregonus artedi are an important component of native food webs in the Great Lakes, and their restoration is instrumental to the recovery of lake trout Salvelinus namaycush and Atlantic salmon Salmo salar. Difficulties with visual identification of larvae can confound early life history surveys, as cisco are often difficult to distinguish from lake whitefish C. clupeaformis. We compared traditional visual species identification methods to genetic identifications based on barcoding of the mitochondrial cytochrome C oxidase I gene for 726 coregonine larvae caught in Chaumont Bay, Lake Ontario. We found little agreement between the visual characteristics of cisco identified by genetic barcoding and the most widely used dichotomous key, and the considerable overlap in ranges of traditionally utilized metrics suggest that visual identification of coregonine larvae from Chaumont Bay is impractical. Coregonines are highly variable and plastic species, and often display wide variations in morphometric characteristics across their broad range. This study highlights the importance of developing accurate, geographically appropriate larval identification methods in order to best inform cisco restoration and management efforts.

Thiamine content of eggs and lengths of coho salmon (Oncorhynchus kisutch) in relation to abundance of alewife (Alosa pseudoharengus) in eastern Lake ontario, 2003 to 2006

Science.gov (United States)

Ketola, H.G.; Rinchard, J.; O'Gorman, R.; Begnoche, L.J.; Bishop, D.L.; Greulich, A.W.

2009-01-01

Early mortality syndrome in fry of Great Lakes salmonines is linked to reduced levels of thiamine in eggs, which reflects maternal consumption of forage fishes such as alewife (Alosa pseudoharengus) that contain thiaminase, an enzyme that destroys thiamine. We assessed annual variations in abundance and condition of alewives and thiamine status of coho salmon (Oncorhynchus kisutch) in Lake Ontario. We analyzed total thiamine in eggs of 20 coho salmon collected annually between 2003 and 2006 at the Salmon River Hatchery on the Salmon River, New York. Alewife abundance was assessed annually in southern and eastern Lake Ontario with bottom trawls during late April and early May. Mean thiamine concentration in eggs varied annually, with those collected in 2003 (2.5 nmol/g) being significantly higher than those collected in 2004 to 2006 (1.5 to 1.7 nmol/g). Although we did not test survival of fry, if reported threshold levels of thiamine for preventing mortality of Lake Michigan coho salmon fry apply, then many or most Lake Ontario coho salmon produced fry were likely to incur thiamine-deficiency mortality, especially during years 2004 to 2006. Comparison to indices of annual abundance of alewife in Lake Ontario with thiamine concentration in coho salmon eggs failed to show any significant correlations (P > 0.05). However, total length of female spawning coho salmon was positively correlated (P < 0.05) with increasing condition and estimated energy content of adult alewives in the previous spring. These results suggest that growth of coho salmon in Lake Ontario was first limited by energy intake, whereas the amount of thiamine provided by alewives was sufficient for growth (in length) but not for producing thiamine-adequate eggs.

Crustacean plankton communities in forty-five lakes in the experimental lakes area, northwestern Ontario

Energy Technology Data Exchange (ETDEWEB)

Patalas, K

1971-01-01

Zooplankton communities were characterized on the basis of samples taken in summer as vertical net hauls in the central part of lakes. Twenty-eight species of crustaceans were found in the 45 lakes studied. The highest number of species as well as the highest numbers of individuals (per unit of area) usually occurred in the largest deepest lakes with most transparent water.

Expanded spatial extent of the Medieval Climate Anomaly revealed in lake-sediment records across the boreal region in northwest Ontario.

Science.gov (United States)

Laird, Kathleen R; Haig, Heather A; Ma, Susan; Kingsbury, Melanie V; Brown, Thomas A; Lewis, C F Michael; Oglesby, Robert J; Cumming, Brian F

2012-09-01

Multi-decadal to centennial-scale shifts in effective moisture over the past two millennia are inferred from sedimentary records from six lakes spanning a ~250 km region in northwest Ontario. This is the first regional application of a technique developed to reconstruct drought from drainage lakes (open lakes with surface outlets). This regional network of proxy drought records is based on individual within-lake calibration models developed using diatom assemblages collected from surface sediments across a water-depth gradient. Analysis of diatom assemblages from sediment cores collected close to the near-shore ecological boundary between benthic and planktonic diatom taxa indicated this boundary shifted over time in all lakes. These shifts are largely dependent on climate-driven influences, and can provide a sensitive record of past drought. Our lake-sediment records indicate two periods of synchronous signals, suggesting a common large-scale climate forcing. The first is a period of prolonged aridity during the Medieval Climate Anomaly (MCA, c. 900-1400 CE). Documentation of aridity across this region expands the known spatial extent of the MCA megadrought into a region that historically has not experienced extreme droughts such as those in central and western north America. The second synchronous period is the recent signal of the past ~100 years, which indicates a change to higher effective moisture that may be related to anthropogenic forcing on climate. This approach has the potential to fill regional gaps, where many previous paleo-lake depth methods (based on deeper centrally located cores) were relatively insensitive. By filling regional gaps, a better understanding of past spatial patterns in drought can be used to assess the sensitivity and realism of climate model projections of future climate change. This type of data is especially important for validating high spatial resolution, regional climate models. © 2012 Blackwell Publishing Ltd.

POST-DREISSENID INCREASES IN TRANSPARENCY DURING SUMMER STRATIFICATION IN THE OFFSHORE WATERS OF LAKE ONTARIO: IS A REDUCTION IN WHITING EVENTS THE CAUSE?

Science.gov (United States)

This recent publication uses data from EPA's long-term Great Lakes monitoring programs and data from Environment Canada to investigate Dreissenid impacts on calcium concentrations and summer water clarity in Lake Ontario. Since the dreissenid invasion of the lower Great Lakes, c...

Assessing diet compositions of Lake Ontario predators using fatty acid profiles of prey fishes

Science.gov (United States)

Happell, Austin; Pattridge, Robert; Rinchard, Jacques; Walsh, Maureen

2017-01-01

Fatty acid profiles are used in food web studies to assess trophic interactions between predator and prey. The present study provides the first comprehensive fatty acid dataset for important prey and predator species in Lake Ontario. Three major prey fish (alewife, rainbow smelt, and round goby) were collected at three sites along the southern shore of Lake Ontario during the spring and fall of 2013, and predator species were collected in similar locations during the summer of 2013. Fatty acid compositions were compared among all prey species, all predator species, and information from both predator and prey was used to infer foraging differences among predators. Seasonal differences in fatty acids were found within each prey species studied. Differences among prey species were greater than any spatio-temporal differences detected within species. Fatty acids of predators revealed species-specific differences that matched known foraging habits. Chinook and Coho salmon, which are known to select alewife as their dominant prey item, had relatively little variation in fatty acid profiles. Conversely, brown trout, lake trout, yellow perch and esocids had highly variable fatty acid profiles and likely highly variable diet compositions. In general, our data suggested three dominant foraging patterns: 1) diet composed of nearly exclusively alewife for Chinook and Coho Salmon; 2) a mixed diet of alewife and round goby for brown and lake trout, and both rock and smallmouth bass; 3) a diet that is likely comprised of forage fishes other than those included in our study for northern pike and chain pickerel.

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.

Aquatic dispersion modelling of a tritium plume in Lake Ontario

International Nuclear Information System (INIS)

Klukas, M.H.; Moltyaner, G.L.

1996-05-01

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 m 2 s -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

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

Science.gov (United States)

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

2018-05-08

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

Uranium and thorium deposits of Northern Ontario

International Nuclear Information System (INIS)

Robertson, J.A.; Gould, K.L.

1983-01-01

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

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.

A hydrological prediction system based on the SVS land-surface scheme: efficient calibration of GEM-Hydro for streamflow simulation over the Lake Ontario basin

Directory of Open Access Journals (Sweden)

É. Gaborit

2017-09-01

Full Text Available This work explores the potential of the distributed GEM-Hydro runoff modeling platform, developed at Environment and Climate Change Canada (ECCC over the last decade. More precisely, the aim is to develop a robust implementation methodology to perform reliable streamflow simulations with a distributed model over large and partly ungauged basins, in an efficient manner. The latest version of GEM-Hydro combines the SVS (Soil, Vegetation and Snow land-surface scheme and the WATROUTE routing scheme. SVS has never been evaluated from a hydrological point of view, which is done here for all major rivers flowing into Lake Ontario. Two established hydrological models are confronted to GEM-Hydro, namely MESH and WATFLOOD, which share the same routing scheme (WATROUTE but rely on different land-surface schemes. All models are calibrated using the same meteorological forcings, objective function, calibration algorithm, and basin delineation. GEM-Hydro is shown to be competitive with MESH and WATFLOOD: the NSE  √  (Nash–Sutcliffe criterion computed on the square root of the flows is for example equal to 0.83 for MESH and GEM-Hydro in validation on the Moira River basin, and to 0.68 for WATFLOOD. A computationally efficient strategy is proposed to calibrate SVS: a simple unit hydrograph is used for routing instead of WATROUTE. Global and local calibration strategies are compared in order to estimate runoff for ungauged portions of the Lake Ontario basin. Overall, streamflow predictions obtained using a global calibration strategy, in which a single parameter set is identified for the whole basin of Lake Ontario, show accuracy comparable to the predictions based on local calibration: the average NSE  √  in validation and over seven subbasins is 0.73 and 0.61, respectively for local and global calibrations. Hence, global calibration provides spatially consistent parameter values, robust performance at gauged locations, and reduces the

A hydrological prediction system based on the SVS land-surface scheme: efficient calibration of GEM-Hydro for streamflow simulation over the Lake Ontario basin

Science.gov (United States)

Gaborit, Étienne; Fortin, Vincent; Xu, Xiaoyong; Seglenieks, Frank; Tolson, Bryan; Fry, Lauren M.; Hunter, Tim; Anctil, François; Gronewold, Andrew D.

2017-09-01

This work explores the potential of the distributed GEM-Hydro runoff modeling platform, developed at Environment and Climate Change Canada (ECCC) over the last decade. More precisely, the aim is to develop a robust implementation methodology to perform reliable streamflow simulations with a distributed model over large and partly ungauged basins, in an efficient manner. The latest version of GEM-Hydro combines the SVS (Soil, Vegetation and Snow) land-surface scheme and the WATROUTE routing scheme. SVS has never been evaluated from a hydrological point of view, which is done here for all major rivers flowing into Lake Ontario. Two established hydrological models are confronted to GEM-Hydro, namely MESH and WATFLOOD, which share the same routing scheme (WATROUTE) but rely on different land-surface schemes. All models are calibrated using the same meteorological forcings, objective function, calibration algorithm, and basin delineation. GEM-Hydro is shown to be competitive with MESH and WATFLOOD: the NSE √ (Nash-Sutcliffe criterion computed on the square root of the flows) is for example equal to 0.83 for MESH and GEM-Hydro in validation on the Moira River basin, and to 0.68 for WATFLOOD. A computationally efficient strategy is proposed to calibrate SVS: a simple unit hydrograph is used for routing instead of WATROUTE. Global and local calibration strategies are compared in order to estimate runoff for ungauged portions of the Lake Ontario basin. Overall, streamflow predictions obtained using a global calibration strategy, in which a single parameter set is identified for the whole basin of Lake Ontario, show accuracy comparable to the predictions based on local calibration: the average NSE √ in validation and over seven subbasins is 0.73 and 0.61, respectively for local and global calibrations. Hence, global calibration provides spatially consistent parameter values, robust performance at gauged locations, and reduces the complexity and computation burden of the

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.

Radionuclide levels in vegetation growing on uranium tailings, Elliot Lake, Ontario

International Nuclear Information System (INIS)

Pave, N.K.; Cloutier, N.R.; Lim, T.P.

1985-01-01

In Elliot Lake, Ontario, Canada, most of the inactive uranium tailings have been reclaimed by revegetation where a thick vegetation cover has been established. The surface amendments have also prompted volunteer growth of various species of local trees and shrubs on tailings. Radionuclide levels were measured in various tissues of grasses, legumes and trees growing on uranium tailings at different sites. 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

Predictive models of benthic invertebrate methylmercury in Ontario and Quebec lakes

Energy Technology Data Exchange (ETDEWEB)

Rennie, M.D.; Collins, N.C.; Purchase, C.F. [Toronto Univ., ON (Canada). Dept. of Biology; Tremblay, A. [Hydro-Quebec, Montreal, PQ (Canada)

2005-12-01

In both North America and Europe, high levels of mercury have been reported in lakes that do not receive obvious point-source mercury inputs. Concern over high contaminant levels in waterfowl and fish have prompted several government-issued advisories on safe levels of fish and wildlife intake for humans. Although the primary source of mercury in pristine lakes is directly through atmospheric deposition or indirectly via terrestrial runoff, there can be large variations in mercury concentrations in organisms in neighbouring lakes. Therefore, factors other than atmospheric deposition must influence bioavailability and accumulation of mercury in aquatic organisms. For that reason, multivariate analyses on benthic invertebrate methylmercury concentrations and water chemistry from 12 Quebec water bodies were used to construct simple, predictive models of benthic invertebrate methylmercury in 23 lakes in Ontario and Quebec. The study showed that the primary means of mercury accumulation for organisms in higher trophic positions is dietary through the assimilation of organic forms of mercury, principally methylmercury. The data from 12 Quebec water bodies, revealed that benthic invertebrates in reservoirs have higher methylmercury than those in natural lakes, and methylmercury is generally higher in predatory invertebrates. Reservoir age was found to correlate with fish, benthic invertebrate methylmercury, and also with lake chemistry parameters such as pH and dissolved organic carbon (DOC). The objective of the study was to determine the appropriate level of taxonomic or functional resolution for generating benthic invertebrate methylmercury models, and to identify which environmental variables correlate most with benthic invertebrate methylmercury. Empirical models using these correlations were constructed and their predicted efficiency was tested by cross-validation. In addition, the effect of exposure to fish digestive enzymes on invertebrate methylmercury was

Results of ground level radiation measurements in support of the 1978 aerial survey of the Lake Ontario Ordnance Works, Lewiston, New York

International Nuclear Information System (INIS)

Berven, B.A.; Doane, R.W.; Haywood, F.F.; Shinpaugh, W.H.

1979-09-01

This report contains the results of a limited series of measurements at the Lake Ontario Ordnance Works site, three miles northeast of Lewiston, New York. The scope of this survey was not extensive, and the survey was conducted to support a concurrent aerial survey conducted by EG and G, Inc. Results of this survey indicate two souces of significant external gamma exposure on the site as well as several locations that retain low to intermediate levels of radioactivity in soil. Off-site soil radionuclide concentrations were well within background levels with one exception. Water radionuclide concentrations on the site in the Central Drainage Ditch are significantly above background levels but decrease with distance from the spoil pile, and are within restrictive concentration guides for off-site locations

Diet shift of double-crested cormorants in eastern Lake Ontario associated with the expansion of the invasive round goby

Science.gov (United States)

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

2010-01-01

The proliferation of the invasive round goby (Apollonia melanostoma) in the Great Lakes has caused shifts in the trophic ecology in some areas. We examined the diet of double-crested cormorants (Phalacrocorax auritas) prior to, and immediately after, round goby population expansion at two colonies, Pigeon and Snake Islands, in eastern Lake Ontario from 1999 to 2007. Cormorant diet was determined from the examination of 10,167 pellets collected over the nine-year period. By the second year round gobies were found in the diet (2002 at Snake Island and 2003 at Pigeon Island) they were the main species consumed by cormorants at each colony. The dominance of round goby in cormorant diets had a significant effect on both daily fish consumption and seasonal trends in fish consumption compared to the pre-goby years. Seasonal differences that were observed during the pre-goby years were lost once gobies became the main diet component of cormorants. The rapid switch to a benthic prey such as round goby, from a largely limnetic fish diet demonstrates the adaptive foraging ability of cormorants. Round goby may act as a buffer for yellow perch and smallmouth bass, two sport fish impacted by cormorant predation in eastern Lake Ontario.

SF6 ventilation study at Agnew Lake Mines, Ontario

International Nuclear Information System (INIS)

1979-03-01

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 (SF 6 ) 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 SF 6 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

Integrative analysis of the Lake Simcoe watershed (Ontario, Canada) as a socio-ecological system.

Science.gov (United States)

Neumann, Alex; Kim, Dong-Kyun; Perhar, Gurbir; Arhonditsis, George B

2017-03-01

Striving for long-term sustainability in catchments dominated by human activities requires development of interdisciplinary research methods to account for the interplay between environmental concerns and socio-economic pressures. In this study, we present an integrative analysis of the Lake Simcoe watershed, Ontario, Canada, as viewed from the perspective of a socio-ecological system. Key features of our analysis are (i) the equally weighted consideration of environmental attributes with socioeconomic priorities and (ii) the identification of the minimal number of key socio-hydrological variables that should be included in a parsimonious watershed management framework, aiming to establish linkages between urbanization trends and nutrient export. Drawing parallels with the concept of Hydrological Response Units, we used Self-Organizing Mapping to delineate spatial organizations with similar socio-economic and environmental attributes, also referred to as Socio-Environmental Management Units (SEMUs). Our analysis provides evidence of two SEMUs with contrasting features, the "undisturbed" and "anthropogenically-influenced", within the Lake Simcoe watershed. The "undisturbed" cluster occupies approximately half of the Lake Simcoe catchment (45%) and is characterized by low landscape diversity and low average population density watershed management practices and provides directions in order to promote environmental programs for lake conservation and to increase public awareness and engagement in stewardship initiatives. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

Science.gov (United States)

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

2013-01-01

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

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.

The deep chlorophyll layer in Lake Ontario: Extent, mechanisms of formation, and abiotic predictors

Science.gov (United States)

Scofield, Anne E.; Watkins, James M.; Weidel, Brian C.; Luckey, Frederick J.; Rudstam, Lars G.

2017-01-01

Epilimnetic production has declined in Lake Ontario, but increased production in metalimnetic deep chlorophyll layers (DCLs) may compensate for these losses. We investigated the spatial and temporal extent of DCLs, the mechanisms driving DCL formation, and the use of physical variables for predicting the depth and concentration of the deep chlorophyll maximum (DCM) during April–September 2013. A DCL with DCM concentrations 2 to 3 times greater than those in the epilimnion was present when the euphotic depth extended below the epilimnion, which occurred primarily from late June through mid-August. In situ growth was important for DCL formation in June and July, but settling and photoadaptation likely also contributed to the later-season DCL. Supporting evidence includes: phytoplankton biovolume was 2.4 × greater in the DCL than in the epilimnion during July, the DCL phytoplankton community of July was different from that of May and the July epilimnion (p = 0.004), and there were concurrences of DCM with maxima in fine particle concentration and dissolved oxygen saturation. Higher nutrient levels in the metalimnion may also be a necessary condition for DCL formation because July metalimnetic concentrations were 1.5 × (nitrate) and 3.5 × (silica) greater than in the epilimnion. Thermal structure variables including epilimnion depth, thermocline depth, and thermocline steepness were useful for predicting DCM depth; the inclusion of euphotic depth only marginally improved these predictions. However, euphotic depth was critical for predicting DCM concentrations. The DCL is a productive and predictable feature of the Lake Ontario ecosystem during the stratified period.

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 and...

FERC approves process for Lake Erie link: Project meets significant regulatory milestone

International Nuclear Information System (INIS)

Anon

2002-01-01

The Federal Electric Regulatory Commission (FERC) of the United States has issued an order to TransEnergie US Ltd., and Hydro One Inc., authorizing the sale of transmission rights for the proposed Lake Erie link. This project will consists of bi-directional high voltage direct current facilities connecting the transmission grids of Ontario, Canada and the United States. The sale is authorized to proceed via a non-discriminatory 'open season' process. The project will consist of buried underwater cables under Lake Erie connecting the transmission systems near Simcoe, Ontario with those in the US at either, or both, of Springfield, Pennsylvania, and Ashtabula, Ohio. The project will provide an increase in transmission capability of up to 975 MW between the electric control areas of the Ontario Independent Electricity Market Operator, the East Central Area Reliability Coordination Agreement in Ohio and the Pennsylvania-New Jersey-Maryland Interconnection. The Lake Erie Link will be financially supported by those consumers who see value in the associated transmission rights, rather than through the regulated rates paid by transmission customers in general. The article provides an overview of the background of the Lake Erie Link, the cable system, the converter station, and the potential economic benefits

Lake sturgeon population characteristics in Rainy Lake, Minnesota and Ontario

Science.gov (United States)

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

2006-01-01

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

Deep lake water cooling a renewable technology

Energy Technology Data Exchange (ETDEWEB)

Eliadis, C.

2003-06-01

In the face of increasing electrical demand for air conditioning, the damage to the ozone layer by CFCs used in conventional chillers, and efforts to reduce the greenhouse gases emitted into the atmosphere by coal-fired power generating stations more and more attention is focused on developing alternative strategies for sustainable energy. This article describes one such strategy, namely deep lake water cooling, of which the Enwave project recently completed on the north shore of Lake Ontario is a prime example. The Enwave Deep Lake Water Cooling (DLWC) project is a joint undertaking by Enwave and the City of Toronto. The $180 million project is unique in design and concept, using the coldness of the lake water from the depths of Lake Ontario (not the water itself) to provide environmentally friendly air conditioning to office towers. Concurrently, the system also provides improved quality raw cold water to the city's potable water supply. The plant has a rated capacity of 52,200 tons of refrigeration. The DLWC project is estimated to save 75-90 per cent of the electricity that would have been generated by a coal-fired power station. Enwave, established over 20 years ago, is North America's largest district energy system, delivering steam, hot water and chilled water to buildings from a central plant via an underground piping distribution network. 2 figs.

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

International Nuclear Information System (INIS)

Chen, S.

1991-01-01

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 E p /E s of 5% to 30%, and about 80% of the events with E s /E p 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

Quantification of virus genes provides evidence for seed-bank populations of phycodnaviruses in Lake Ontario, Canada.

Science.gov (United States)

Short, Cindy M; Rusanova, Oksana; Short, Steven M

2011-05-01

Using quantitative PCR, the abundances of six phytoplankton viruses DNA polymerase (polB) gene fragments were estimated in water samples collected from Lake Ontario, Canada over 26 months. Four of the polB fragments were most related to marine prasinoviruses, while the other two were most closely related to cultivated chloroviruses. Two Prasinovirus-related genes reached peak abundances of >1000 copies ml(-1) and were considered 'high abundance', whereas the other two Prasinovirus-related genes peaked at abundances bank populations with members that can become numerically dominant when their host abundances reach appropriate levels.

Neotectonic investigations in Southern Ontario. Prince Edward County - Phase 2

International Nuclear Information System (INIS)

McFall, G.H.; Allam, A.

1991-06-01

This report summarizes the preliminary results of geological and geophysical investigations and offshore side scan sonar surveys of the bedrock and unconsolidated sediments in Prince Edward County, Southern Ontario, by the Ontario Geological Survey in 1989. Investigations were focused on deformations in the bedrock and the surficial deposits. Some of these deformations may be neotectonic in origin. Low magnitude seismicity in the Prince Edward County region appears to be spatially related to a major regional fault system that crosses Lake Ontario and consists of the seismically active Clarendon-Linden Fault System in New York State, the Picton-Napanee and Rideau Faults, the Frontenac-Sharbot Lake Terrane Boundary and the assumed Salmon River Fault in Ontario. Detailed observations were made in the Long Point study area and the Mountain View and Picton Quarries. Bedrock structural features were documented, including: joints; normal, reverse and strike strip faults; brittle folds; and Jurassic age ultramafic dyke. Detailed refraction seismic surveys were conducted across a local fault and possible fold structures. Magnetic surveys, conducted in conjunction with the offshore side scan sonar surveys, documented large magnetic anomalies southeast of Point Petre and at the northeast end of Long Reach. Side scan sonar surveys of the lake bottom to the east of Point Petre confirm the presence of pop-ups in that area of the lake bottom which is immediately adjacent to where pop-ups are observed on land. The pop-ups present in the lake bottom have similar orientations to those mapped in the study area

2013 status of the Lake Ontario lower trophic levels

Science.gov (United States)

Holeck, Kristen T.; Rudstam, Lars G.; Hotaling, Christopher; McCullough, Russ D.; Lemon, Dave; Pearsall, Web; Lantry, Jana R.; Connerton, Michael J.; LaPan, Steve; Trometer, Betsy; Lantry, Brian F.; Walsh, Maureen; Weidel, Brian C.

2014-01-01

Phosphorus showed high variation across nearshore (10 m depth) sites but was more stable at offshore (20 m and deeper) stations. In June and July, sites at the mouth of the Niagara River and at Oak Orchard had high phosphorus concentrations (20 – 46 μg/L). Epilimnetic average April-Oct total phosphorus (TP) ranged between 6.9 and 19.9 μg/L in the nearshore and between 5.8 and 10.2 μg/L in the offshore. Average April-Oct soluble reactive phosphorus (SRP) ranged from 0.9 to 7.3 μg/L in the nearshore and 0.8 to 1.4 μg/L in the offshore. TP and SRP were significantly higher in the nearshore than in the offshore.Spring TP has declined in the longer data series (since 1981), but not since 1995. It averaged 8.4 μg/L in the nearshore and 5.0 μg/L in the offshore in 2013—below the 10 μg/L target set by the Great Lakes Water Quality Agreement of 1978 for offshore waters of Lake Ontario.Offshore summer chlorophyll-a declined significantly in both the short- (1995-2013) and long-term (1981-2013) time series at a rate of 3-4% per year. Nearshore chlorophyll-a increased after 2003 but then declined again after 2009. Epilimnetic chlorophyll-aaveraged between 0.5 and 1.3 μg/L across sites with no difference between nearshore and offshore habitats. Average seasonal Secchi disk depth ranged from 4.5 m to 10.6 m and was higher in the offshore (average 8.1 m) than nearshore stations (6.3 m). These values are indicative of oligotrophic conditions in both habitats.In 2013, Apr/May - Oct epilimnetic zooplankton size and total biomass were significantly higher in the offshore than the nearshore. However, with the exception of Limnocalanus (higher in offshore), there were no differences between habitats for any of the zooplankton groups.Most of the zooplankton biomass was in the metalimnion and hypolimnion during the day in 2013. Between 65 and 98% of zooplankton biomass was found below the thermocline throughout the year.The predatory cladoceran Cercopagis continued to be

2014 status of the Lake Ontario lower trophic levels

Science.gov (United States)

Holeck, Kristen T.; Rudstam, Lars G.; Hotaling, Christopher; McCullough, Russ D.; Lemon, Dave; Pearsall, Web; Lantry, Jana; Connerton, Michael J.; LaPan, Steve; Biesinger, Zy; Lantry, Brian F.; Walsh, Maureen; Weidel, Brian C.

2015-01-01

Soluble reactive phosphorus (SRP) concentrations have been stable in nearshore and offshore habitats since 1998 (0.4 – 3.3 μg/L). SRP concentrations were low in 2014; Apr/May – Oct mean values were Water Quality Agreement of 1978 for offshore waters of Lake Ontario. TP concentrations were low at both nearshore and offshore locations; Apr/May – Oct mean values from individual sites ranged from 4.6 – 9.1 μg/L. Spring TP has declined significantly in the longer data series (since 1981), but not since 1995 indicating stable nutrient loading into Lake Ontario for nearly two decades. It averaged 7.8 μg/L in the nearshore and 5.6 μg/L in the offshore in 2014.Chlorophyll-a and secchi depth values are indicative of oligotrophic conditions in nearshore and offshore habitats. Offshore summer chlorophyll-a declined significantly in both the short- (2000-2014) and long-term (1981-2014) time series at a rate of 4-6% per year. Nearshore chlorophyll-a increased after 2003 but then declined again after 2009. Epilimnetic chlorophyll-a averaged between 0.6 and 1.6 μg/L across sites with no difference between nearshore and offshore habitats. Apr/May – Oct Secchi depth ranged from 4.0 m to 10.8 m at individual sites and was higher in the offshore (average 9.1 m) than nearshore (5.9 m).In 2014, Apr/May – Oct epilimnetic zooplankton density, size, and biomass were not different between the offshore and the nearshore, and there were no differences in epilimnetic biomass between offshore and nearshore areas for any of the zooplankton groups.Zooplankton density and biomass peaked in September, an atypical pattern. This coincided with peaks in calanoid copepod, daphnid, and Holopedium biomass. Holopedium biomass in the nearshore increased significantly since 1995.The predatory cladoceran Cercopagis continued to be abundant in the summer, peaking at ~10 mg/m3in the offshore. Bythotrephes biomass was at its lowest level since 2005 in both offshore and nearshore habitats

Effect of stock size, climate, predation, and trophic status on recruitment of alewives in Lake Ontario, 1978-2000

Science.gov (United States)

O'Gorman, Robert; Lantry, Brian F.; Schneider, Clifford P.

2004-01-01

The population of alewives Alosa pseudoharengus in Lake Ontario is of great concern to fishery managers because alewives are the principal prey of introduced salmonines and because alewives negatively influence many endemic fishes. We used spring bottom trawl catches of alewives to investigate the roles of stock size, climate, predation, and lake trophic status on recruitment of alewives to age 2 in Lake Ontario during 1978–2000. Climate was indexed from the temperature of water entering a south-shore municipal treatment plant, lake trophic status was indexed by the mean concentration of total phosphorus (TP) in surface water in spring, and predation was indexed by the product of the number of salmonines stocked and relative, first-year survival of Chinook salmonOncorhynchus tshawytscha. A Ricker-type parent–progeny model suggested that peak production of age-1 alewives could occur over a broad range of spawning stock sizes, and the fit of the model was improved most by the addition of terms for spring water temperature and winter duration. With the addition of the two climate terms, the Ricker model indicated that when water was relatively warm in spring and the winter was relatively short, peak potential production of young was nine times higher than when water temperature and winters were average, and 73 times higher than when water was cold in spring and winters were long. Relative survival from age 1 to recruitment at age 2 was best described by a multiple linear regression with terms for adult abundance, TP, and predation. Mean recruitment of age-2 fish in the 1978–1998 year-classes predicted by using the two models in sequence was only about 20% greater than the observed mean recruitment. Model estimates fit the measured data exceptionally well for all but the largest four year-classes, which suggests that the models will facilitate improvement in estimates of trophic transfer due to alewives.

Local infestation or long-distance migration? The seasonal recolonization of dairy farms by Stomoxys calcitrans (Diptera: Muscidae) in south central Ontario, Canada.

Science.gov (United States)

Beresford, D V; Sutcliffe, J F

2009-04-01

Stable fly (Diptera: Muscidae) populations in south central Ontario, Canada, first occur on dairy farms in late spring, grow exponentially throughout the summer, and are frozen back each autumn. We examined the extent of overwinter persistence on 22 dairy farms in a 55- by 60-km region north of Lake Ontario that spans four climatic zones. Our overwintering sampling of larval habitat identified three farms located in the southern section of the study region as potential overwintering refugia. Using sticky trap catches to identify the timing of first spring appearance at each farm, we then tested two models of how local farm populations are reestablished annually: 1) stable flies disperse from local climatic refuges and colonize neighboring farms (the local source model); and 2) stable flies are carried into the study region by frontal weather systems (the distant source model). The timing of when stable flies first occurred at these farms supported a local source of dispersing colonists from a small proportion of local refuge farms. We discuss our results in terms of how yearly fluctuation in climate would affect refuge farm density in the region and how this, in turn, would shift the recolonization dynamic. Implications for controlling stable flies also are discussed.

Overview of the environmental impact assessment for the proposed expansion of the Elliot Lake Ontario uranium mines

International Nuclear Information System (INIS)

Gorber, D.M.; Graham, R.G.; Ibbotson, B.G.

1978-01-01

As a result of the resurgence in the demand for uranium, Denison Mines Limited and Rio Algom Limited began preparations, in 1973 and 1974 respectively, for expansion of their facilities at Elliot Lake, Ontario. These programmes involved not only the expansion of facilities currently in operation in the area, but also the rehabilitation of non-operating properties that were previously used during the 1960's. This paper reviews the methodology employed during the environmental assessment study of the proposed expansion and highlights the long and short-term strategies recommended

Large catchment area recharges Titan's Ontario Lacus

Science.gov (United States)

Dhingra, Rajani D.; Barnes, Jason W.; Yanites, Brian J.; Kirk, Randolph L.

2018-01-01

We seek to address the question of what processes are at work to fill Ontario Lacus while other, deeper south polar basins remain empty. Our hydrological analysis indicates that Ontario Lacus has a catchment area spanning 5.5% of Titan's surface and a large catchment area to lake surface area ratio. This large catchment area translates into large volumes of liquid making their way to Ontario Lacus after rainfall. The areal extent of the catchment extends to at least southern mid-latitudes (40°S). Mass conservation calculations indicate that runoff alone might completely fill Ontario Lacus within less than half a Titan year (1 Titan year = 29.5 Earth years) assuming no infiltration. Cassini Visual and Infrared Mapping Spectrometer (VIMS) observations of clouds over the southern mid and high-latitudes are consistent with precipitation feeding Ontario's large catchment area. This far-flung rain may be keeping Ontario Lacus filled, making it a liquid hydrocarbon oasis in the relatively dry south polar region.

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

Science.gov (United States)

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

2016-06-01

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

Targets set to reduce Lake Erie algae

Science.gov (United States)

Evans, Mary

2016-01-01

In February 2016, the Great Lakes Executive Committee, which oversees the implementation of the Great Lakes Water Quality Agreement (GLWQA) between the U.S. and Canada, approved phosphorus loading targets for Lake Erie to reduce the size of harmful algal blooms (HABs), reduce the presence of the low oxygen zone in the central basin, and protect nearshore water quality. The targets are set with respect to the nutrient loads calculated for 2008. To reduce the impacts of HABs on Lake Erie a target was set of a 40 percent reduction in total and soluble reactive phosphorus loads in the spring from two Canadian rivers and several Michigan and Ohio rivers, especially the Maumee River (https://binational.net/2016/02/22/ finalptargets-ciblesfinalesdep/). States and the province of Ontario are already developing Domestic Action Plans to accomplish the reductions and scientists are developing research and monitoring plans to assess progress.

Managing an oak decline crisis in Oakville, Ontario: lessons learned

Science.gov (United States)

Peter A. Williams; John W. McNeil; Kurt W. Gottschalk; Robert A. Haack

2013-01-01

The town of Oakville, Ontario, is located along the north shore of Lake Ontario between Toronto and Hamilton. In the fall of 2002, significant oak (Quercus spp.) mortality was observed at Oakville's Iroquois Shoreline Woods Park, an environmentally significant forest remnant noted for its oak-dominated forests. Investigations suggested that oak...

Benthic fauna of 41 acid sensitive headwater lakes in north central Ontario. [Chironomidae salinarius; Chironomidae anthracinus; Tanytarsini

Energy Technology Data Exchange (ETDEWEB)

Dermott, R.; Kelso, J.R.M.; Douglas, A.

1986-01-01

The benthic fauna of 41 nonhumic, soft water lakes situated north of lakes Superior and Huron were sampled during 1980. The pH range of the lakes sampled was 4.6 to 7.7. The benthic infauna displayed regional differences in abundance and composition, with large variation with each district. Total abundance, biomass, and number of taxa were not correlated with lake pH or alkalinity. The Chironomidae displayed a slight change in percent composition of the major species with lower pH. The Tanytarsini and Chironomus Salinarius group decreased, while C. anthracinus group increased in relative abundance in those lakes with lower pH. Other factors appear to control the distribution of the various invertebrate orders, with depth and sediment nature being important variables.

Structural contour, isopach and feature maps of quaternary sediments in Western Lake Ontario

International Nuclear Information System (INIS)

Lewis, C.F.M.; King, E.L.; Todd, B.J.; Blasco, S.M.

1995-06-01

A systematic high-resolution acoustic reconnaissance survey of Quaternary sediments (> 50 m thick, in places) and the underlying bedrock surface was completed for western Lake Ontario between Burlington and Port Hope, Ontario, to determine if geophysical lineaments through the area of Pickering and Darlington nuclear power stations are potentially seismically active. A total of 2530 line-km of data were obtained along N-S and E-W lines spaced 10 and 5 km respectively, using a high-resolution subbottom profiler (boomer and IKB-SEISTEC), a 100 kHz sidescan sonar (150-m range) with 3.5 kHz profiler, a 10 or 40 cu. in. sleeve gun seismic reflection system, and, intermittently, a marine magnetometer. Six piston cores up to 15-m long were collected to compare sediment lithology with key regional seismic reflectors. Sediments deposited over the past 13,000 years were imaged with vertical resolution in the order of 10-30 cm just below the lakebed and less than 1 m at the bedrock surface; resolution for the sleeve gun system is approximately 3-5 m. Digital processing and rescaling of selected seismic profiles aided interpretation. Structural contour maps for three Quaternary sequence boundaries and the bedrock surface were generated together with the related sequence isopach maps. Three additional maps portray lakebed features identified on sidescan sonar records and subsurface features identified on seismic profiles. All maps are at 1:250,000 scale. (author). 2 tabs., 48 figs., 12 maps

Bottom trawl assessment of Lake Ontario prey fishes

Science.gov (United States)

Weidel, Brian C.; Connerton, Michael J.; Holden, Jeremy

2018-01-01

Managing Lake Ontario fisheries in an ecosystem-context requires prey fish community and population data. Since 1978, multiple annual bottom trawl surveys have quantified prey fish dynamics to inform management relative to published Fish Community Objectives. In 2017, two whole-lake surveys collected 341 bottom trawls (spring: 204, fall: 137), at depths from 8-225m, and captured 751,350 fish from 29 species. Alewife were 90% of the total fish catch while Deepwater Sculpin, Round Goby, and Rainbow Smelt comprised the majority of the remaining total catch (3.8, 3.1, and 1.1% respectively). The adult Alewife abundance index for US waters increased in 2017 relative to 2016, however the index for Canadian waters declined. Adult Alewife condition, assessed by the predicted weight of a 165 mm fish (6.5 inches), declined in 2017 from record high values observed in spring 2016. Spring 2017 Alewife condition was slightly less than the 10-year average, but the fall value was well below the 10-year average, likely due to increased Age-1 Alewife abundance. The Age-1 Alewife abundance index was the highest observed in 40 years, and 8-times higher than the previous year. The Age-1 index estimates Alewife reproductive success the preceding year. The warm summer and winter of 2016 likely contributed to the large year class. In contrast the relatively cool 2017 spring and cold winter may result in a lower than average 2017 year class. Abundance indices for Rainbow Smelt, Cisco, and Emerald Shiner either declined or remained at low levels in 2017. Pelagic prey fish diversity continues to be low since a single species, Alewife, dominates the catch. Deepwater Sculpin were the most abundant benthic prey fish in 2017 because Round Goby abundance declined sharply from 2016. Slimy Sculpin density continued to decline and the 2017 biomass index for US waters was the lowest ever observed. Prior to Round Goby proliferation, juvenile Slimy Sculpin comprised ~10% of the Slimy Sculpin catch, but

Monitoring lake level changes by altimetry in the arid region of Central Asia

Science.gov (United States)

Zhao, Y.; Liao, J. J.; Shen, G. Z.; Zhang, X. L.

2017-07-01

The study of lake level changes in arid region of Central Asia not only has important significance for the management and sustainable development of inland water resources, but also provides the basis for further study on the response of lakes to climate change and human activities. Therefore, in this paper, eleven typical lakes in Central Asia were observed. The lake edges were obtained through image interpretation using the quasi-synchronous MODIS image, and then water level information with long period (2002-2015) was acquired using ENVISAT/RA-2 and Cryosat-2 satellite borne radar altimeter data. The results show that these 11 lakes all have obvious seasonal changes of water level in a year with a high peak at different month. During 2002 - 2015, their water levels present decreased trend generally except Sarygamysh Lake, Alakol Lake and North Aral Sea. The alpine lakes are most stables, while open lakes’ levels change the most violently and closed lakes change diversely among different lakes.

Cordova Lake dam hydroelectric generating station case study

International Nuclear Information System (INIS)

Kerr, D.; Huxley, J.

1993-01-01

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

The uranium deposits of Ontario

International Nuclear Information System (INIS)

Robertson, J.A.

1981-01-01

The principal types of uranium deposits in Ontario are carbonatites and fenites, alkalic volcanic rocks, pegiatites, calc-silicate rocks, pyritic quartz-pebble conglomerates, polymictic conglomerates and some pelitic rocks, and various 'pitchblende' deposits including late Precambrian unconformities, possibly late Precambrian diabase dikes, and other unconformities: carbonates, sandstones, lignites, and semi-pelitic rocks of middle and upper Precambrian age. Only red unzoned pegmatite and the pyritic quartz-pebble conglomerate have supported production. Ontario reasonably assured and estimated resources in the economic and subeconomic categories in 1977 amounted to 553 000 tonnes U, and 1977 production was 4000 tonnes U. Measured, indicated, and inferred resources in the Elliot Lake - Agnew Lake area are at least 400 000 tonnes U. The latter deposits are also a significant thorium resource. Geological features reflecting major changes in physics and chemistry are prime controls on distribution of uranium deposits. Geological province and subprovince boundaries, major faults, higher metamorphic grades, domain boundaries related to quartz monzonite batholiths, alkalic complexes, and the distribution of carbonate rocks are examples of such geological features

Ontario's uranium mining industry

International Nuclear Information System (INIS)

Runnalls, O.J.C.

1981-01-01

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

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.

Blood mercury levels among Ontario anglers and sport-fish eaters

International Nuclear Information System (INIS)

Cole, D.C.; Kearney, Jill; Sanin, L.H.; Leblanc, Alain; Weber, J.P.

2004-01-01

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

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

Science.gov (United States)

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

2005-01-01

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

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 (<3.5 m) semi-enclosed lagoon on the shore of Lake Ontario (Frenchman's Bay; 0.85 km(2)). The total chloride delivery to the lagoon from its entire 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.

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.

2009-06-01

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 (< 3.5 m) semi-enclosed lagoon on the shore of Lake Ontario (Frenchman's Bay; 0.85 km 2). The total chloride delivery to the lagoon from its entire 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.

Investigating palaeo-subglacial lakes in the central Barents Sea

Science.gov (United States)

Esteves, M.; Shackleton, C.; Winsborrow, M.; Andreassen, K.; Bjarnadóttir, L. R.

2017-12-01

In the past decade hundreds of subglacial lakes have been detected beneath the Antarctic Ice Sheet, and several more beneath the Greenland Ice Sheet. These are important components of the subglacial hydrological system and can influence basal shear stress, with implications for ice sheet dynamics and mass balance, potentially on rapid timescales. Improvements in our understanding of subglacial hydrological systems are therefore important, but challenging due to the inaccessibility of contemporary subglacial environments. Whilst the beds of palaeo-ice sheets are easier to access, few palaeo-subglacial lakes have been identified due to uncertainties in the sedimentological and geomorphological diagnostic criteria. In this study we address these uncertainties, using a suite of sedimentological, geomorphological and modelling approaches to investigate sites of potential palaeo-subglacial lakes in the central Barents Sea. Geomorphological signatures of hydraulic activity in the area include large meltwater channels, tunnel valleys, and several interlinked basins. Modelling efforts indicate the potential for subglacial hydraulic sinks within the area during the early stages of ice retreat since the Last Glacial Maximum. In support of this, sedimentological observations indicate the presence of a dynamic glaciolacustrine depositional environment. Using the combined results of the modelling, geomorphology, and sedimentological analyses, we conclude that palaeo-subglacial lakes are likely to have formed on the northwestern banks of Thor Iversenbanken, central Barents Sea, and suggest that numerous other subglacial lakes may have been present beneath the Barents Sea Ice Sheet. Furthermore, we investigate and refine the existing diagnostic criteria for the identification of palaeo-subglacial lakes.

Development of FVSOntario: A Forest Vegetation Simulator Variant and application software for Ontario

Science.gov (United States)

Murray E. Woods; Donald C. E. Robinson

2008-01-01

The Ontario Ministry of Natural Resources is leading a government-industry partnership to develop an Ontario variant of the Forest Vegetation Simulator (FVS). Based on the Lake States variant and the PrognosisBC user-interface, the FVSOntarioproject is motivated by a need to model the impacts of intensive forest management...

Modelling the long term impact of climate change on the carbon budget of Lake Simcoe, Ontario using INCA-C.

Science.gov (United States)

Oni, S K; Futter, M N; Molot, L A; Dillon, P J

2012-01-01

This study presents a process-based model of dissolved organic carbon concentration ([DOC]) in catchments draining into Lake Simcoe, Ontario. INCA-C, the Integrated Catchment model for Carbon, incorporates carbon biogeochemical processes in a terrestrial system with hydrologic flow paths to simulate watershed wide [DOC]. The model successfully simulates present-day inter-annual and seasonal [DOC] dynamics in tributaries draining catchments with mixed or contrasting land cover in the Lake Simcoe watershed (LSW). The sensitivity of INCA-C to soil moisture, hydrologic controls and land uses within a watershed demonstrates its significance as a tool to explore pertinent environmental issues specific to the LSW. Projections of climate change under A1B and A2 SRES scenarios suggest a continuous monotonic increase in [DOC] in surface waters draining into Lake Simcoe. Large variations in seasonal DOC dynamics are predicted to occur during summer with a possibility of displacement of summer [DOC] maxima towards winter and a prolongation of summer [DOC] levels into the autumn. INCA-C also predicts possible increases in dissolved inorganic carbon in some tributaries with rising temperature suggesting increased CO(2) emissions from rivers as climate changes. Copyright © 2011 Elsevier B.V. All rights reserved.

Glacial lakes of the Central and Patagonian Andes

Science.gov (United States)

Wilson, Ryan; Glasser, Neil F.; Reynolds, John M.; Harrison, Stephan; Anacona, Pablo Iribarren; Schaefer, Marius; Shannon, Sarah

2018-03-01

The prevalence and increased frequency of high-magnitude Glacial Lake Outburst Floods (GLOFs) in the Chilean and Argentinean Andes suggests this region will be prone to similar events in the future as glaciers continue to retreat and thin under a warming climate. Despite this situation, monitoring of glacial lake development in this region has been limited, with past investigations only covering relatively small regions of Patagonia. This study presents new glacial lake inventories for 1986, 2000 and 2016, covering the Central Andes, Northern Patagonia and Southern Patagonia. Our aim was to characterise the physical attributes, spatial distribution and temporal development of glacial lakes in these three sub-regions using Landsat satellite imagery and image datasets available in Google Earth and Bing Maps. Glacial lake water volume was also estimated using an empirical area-volume scaling approach. Results reveal that glacial lakes across the study area have increased in number (43%) and areal extent (7%) between 1986 and 2016. Such changes equate to a glacial lake water volume increase of 65 km3 during the 30-year observation period. However, glacial lake growth and emergence was shown to vary sub-regionally according to localised topography, meteorology, climate change, rate of glacier change and the availability of low gradient ice areas. These and other factors are likely to influence the occurrence of GLOFs in the future. This analysis represents the first large-scale census of glacial lakes in Chile and Argentina and will allow for a better understanding of lake development in this region, as well as, providing a basis for future GLOF risk assessments.

Jarosite formation in the uranium processing circuit of Denison Mines Limited, Elliot Lake, Ontario

International Nuclear Information System (INIS)

Dutrizac, J.E.

1985-04-01

Jarosite precipitation occurs in several parts of the uranium processing circuit of Denison Mines Limited, Elliot Lake, Ontario. Extensive precipitation of jarosite takes place in the filter cloth and on the drum face of the secondary drum filters, and this precipitation causes severe operating difficulties. Precipitation of jarosite is also observed in the ion exchange beads, but it is not known whether the jarosite is responsible for the observed decrease in resin efficiency. The resin beads are also rimmed with significant quantities of silica, lead, phosphate, sulphate, etc. which could be responsible for the fouling of the resin. In every instance, potassium jarosite, containing only minor amounts of sodium or ammonium, was the observed species; the potassium likely originates from the acid leaching of muscovite in the ore. Potential methods of avoiding the jarosite problem are discussed, but these may not be compatible with the overall process requirements

Report on investigation of remedial measures for the radiation reduction and radioactive decontamination of Elliot Lake, Ontario

International Nuclear Information System (INIS)

1981-02-01

This is the fourth annual report on a program to monitor and reduce radon daughter exposures in the town of Elliot Lake, Ontario. Twelve month's WL survey measurements were completed in 1980 and showed that 22 houses exceeded the remedial action criterion of 0.02 WL. In a few cases gamma radiation levels were high enough to require remedial action in driveways and public areas, but not inside houses. During 1980 remedial work was carried out on 85 buildings; work was completed on 58. The most frequent routes of entry for radon and radon daughters were untrapped weeping tile connected to a floor drain or sump, and the wall to floor joint

Numerical Modelling Approaches for Assessing Improvements to the Flow Circulation in a Small Lake

Directory of Open Access Journals (Sweden)

Cheng He

2011-01-01

Full Text Available Kamaniskeg Lake is a long, narrow, and deep small lake located in the northern part of Ontario, Canada. The goals of this paper were to examine various options to improve the water quality in the northern part of the lake by altering the local hydraulic flow conditions. Towards this end, a preliminary screening suggested that the flow circulation could be increased around a central island (Mask Island in the northern part of the lake by opening up an existing causeway connecting the mainland and central island. Three-dimensional (3D hydraulic and transport models were adopted in this paper to investigate the hydraulic conditions under various wind forces and causeway structures. The modelling results show that opening the causeway in a few places is unlikely to generate a large flow circulation around the central island. Full circulation only appears to be possible if the causeway is fully removed and a strong wind blows in a favourable direction. The possible reasons for existing water quality variations at the intake of a local WTP (water treatment plant are also explored in the paper.

Depositional environments of Late Triassic lake, east-central New Mexico

Energy Technology Data Exchange (ETDEWEB)

Hester, P.M. (Bureau of Land Management, Albuquerque, NM (USA))

1989-09-01

The Redonda Member of the Chinle Formation represents deposition in a large, polymictic lake during the Late Triassic (Norian) in east-central New Mexico. This study documents and defines an extensive lacustrine system situated in western Pangaea which was influenced by both tectonic and climatic events. Areal extent of the lake may have been as much as 5,000 km{sup 2}.

Zooplankton from Lake Magelungen, Central Sweden 1960-1963

International Nuclear Information System (INIS)

Almquist, Elisabeth

1970-11-01

The investigation of the zooplankton of Lake Magelungen, Central Sweden, was carried out over a period of three years. The aim of the investigation was to illustrate the qualitative and quantitative composition of the zooplankton before the release of waste water from the Aagesta Heat and Power Station began. Vertical sampling series were collected once a month at three different stations in the lake. The highest volumes of zooplankton were obtained in the summer. The ciliates predominated when the conditions were unfavourable for other zooplankton, as in winter just below the ice. The rotifers dominated during and immediately after the spring circulation. With one exception the crustaceans reached their peak volume values in August or September. The composition of the zooplankton indicates that Lake Magelungen is highly eutrophic

Zooplankton from Lake Magelungen, Central Sweden 1960-1963

Energy Technology Data Exchange (ETDEWEB)

Almquist, Elisabeth

1970-11-15

The investigation of the zooplankton of Lake Magelungen, Central Sweden, was carried out over a period of three years. The aim of the investigation was to illustrate the qualitative and quantitative composition of the zooplankton before the release of waste water from the Aagesta Heat and Power Station began. Vertical sampling series were collected once a month at three different stations in the lake. The highest volumes of zooplankton were obtained in the summer. The ciliates predominated when the conditions were unfavourable for other zooplankton, as in winter just below the ice. The rotifers dominated during and immediately after the spring circulation. With one exception the crustaceans reached their peak volume values in August or September. The composition of the zooplankton indicates that Lake Magelungen is highly eutrophic

Application of a Spectral Wave Model to Assess Breakwater Configurations at a Small Craft Harbour on Lake Ontario

Directory of Open Access Journals (Sweden)

Amelia H. Cooper

2016-08-01

Full Text Available A surface wave model using three nested grids is applied to the eastern end of Lake Ontario to investigate wave propagation from an open lake environment to a small craft harbour protected by a breakwater. The Simulating WAves Nearshore (SWAN spectral wave model, coupled with the Delft3D hydrodynamic model, is applied to simulate a series of storms in November, 2013. The model results are compared to observations from two pressure sensors, and used to quantify wave properties around existing and future breakwaters to evaluate the bulk changes to the harbour configuration. Overall, the results indicate that the rubblemound breakwater reduces wave heights in the existing harbour by 63% compared to no breakwater, and that the addition of a surface breakwater extension could reduce wave heights by an additional 54%. Wave height attenuation was found to be highly dependent on the incident wave direction relative to breakwater orientation. The spectral wave model is useful for simulating wave transformation for broad directional spectra in wind-sea conditions over large scales to semi-protected areas such as small craft harbours.

Summary of Ontario Hydro's 1990-91 zebra mussel research program

International Nuclear Information System (INIS)

Claudi, R.; Wiancko, P.M.

1992-01-01

Ontario Hydro is the principal supplier of electricity to the Province of Ontario. It serves 3.6 million customers, with an inservice capacity of 28,200 MW. Ontario Hydro has seven fossil, five nuclear, and four hydraulic stations in the Great Lakes Basin and surrounding watershed. In addition, there are another 60 inland hydraulic stations and numerous dams. As the largest single user of raw water from the Great Lakes Basin, Ontario Hydro recognized the need to control zebra mussels early in 1989. At that time, very little was known in North America about the zebra mussel life cycle and potential impact. European utilities were consulted, but as we now know, zebra mussels are not perceived to be a problem in Europe at this time. To satisfy the immediate need for control, chlorination was identified as the most effective interim measure to prevent the fouling of systems which draw water from the aquatic environment. Due to the current regulatory environment, this solution is considered short term and Ontario Hydro was compelled to initiate a comprehensive research effort aimed at providing alternative methods of control. Most of the research effort during 1990, was methods of control. Most of the research effort during 1990, was directed towards this goal. Many alternative control measures, both chemical and nonchemical were considered. Also considered were the potential effects of the control measures and zebra mussels on station operations. A multidisciplinary team involving aquatic biologists, chemists, corrosion specialists, and civil and mechanical engineers from the various departments of Ontario Hydro was asked to address the problem. Some of the research also involved collaborative studies with universities, US utilities, American Water Works Association, and Canadian industries. Following is a summary of the research effort in 1990, and a preview of the research underway in 1991

Geologic controls on the formation of lakes in north-central Florida

Science.gov (United States)

Kindinger, Jack G.; Davis, Jeffrey B.; Flocks, James G.; Pitman, Janet K.; Carroll, Alan R.

1998-01-01

Fluid exchange between surficial waters and groundwater, as well as the processes that control this exchange, are of critical concern to water management districts and planners. Digital high-resolution seismic systems were used to collect geophysical data from 30 lakes of north-central Florida. Although using seismic profile data in the past has been less than successful, the use of digital technology has increased the potential for success. Seismic profiles collected from the lakes of north-central Florida have shown the potential application of these techniques in understanding the formation of individual lakes. In each case study, lake structure and geomorphology were controlled by solution and/or mechanical processes. Processes that control lake development are twofold: 1) karstification or dissolution of the underlying limestone, and 2) me collapse, subsidence, or slumping of overburden to form sinkholes. Initial lake formation is directly related to the karst topography of the underlying host limestone. Lake size and shape are a factor of the thickness of overburden and size of the collapse or subsidence and/or clustering of depressions allowing for lake development. Lake development is through progressive sequence stages to maturity that can be delineated into geomorphic types. Case studies have shown that lakes can be divided by geomorphic types into progressive developmental phases: (1) active subsidence or collapse phase (young) - the open to partially filled collapse structures typically associated with sink holes; (2) transitional phase (middle age) - the sinkhole is plugged as the voids within the collapse are filled with sediment, periodic reactivation may occur; (3) baselevel phase (mature) - active sinkholes are progressively plugged by the continual erosion of material into the basin, and eventually sediment fills the basins; and (4) polje (drowned prairie) - broad flat-bottom basins located within the epiphreatic zone that are inundated at high

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

Directory of Open Access Journals (Sweden)

John P. SMOL

2003-02-01

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

Lake Baikal isotope records of Holocene Central Asian precipitation

Science.gov (United States)

Swann, George E. A.; Mackay, Anson W.; Vologina, Elena; Jones, Matthew D.; Panizzo, Virginia N.; Leng, Melanie J.; Sloane, Hilary J.; Snelling, Andrea M.; Sturm, Michael

2018-06-01

Climate models currently provide conflicting predictions of future climate change across Central Asia. With concern over the potential for a change in water availability to impact communities and ecosystems across the region, an understanding of historical trends in precipitation is required to aid model development and assess the vulnerability of the region to future changes in the hydroclimate. Here we present a record from Lake Baikal, located in the southern Siberian region of central Asia close to the Mongolian border, which demonstrates a relationship between the oxygen isotope composition of diatom silica (δ18Odiatom) and precipitation to the region over the 20th and 21st Century. From this, we suggest that annual rates of precipitation in recent times are at their lowest for the past 10,000 years and identify significant long-term variations in precipitation throughout the early to late Holocene interval. Based on comparisons to other regional records, these trends are suggested to reflect conditions across the wider Central Asian region around Lake Baikal and highlight the potential for further changes in precipitation with future climate change.

Impacts of urban sprawl on the area of downtown lakes in a highly developing city on central China

Science.gov (United States)

Zhang, W.; Zhang, Y.

2016-12-01

Wuhan city in central China is full of water resources and numerous lakes are located. Downtown lakes have significant ecological value and ornamental value for urban inhabitants in Wuhan. Under the rapid process of urban sprawl, downtown lakes are occupied by impervious areas. This research uses Landsat images to extract land uses from 1991 to 2013 in Wuhan city , and attempts to find out how urban sprawl affects the water body area decline in space. Two largest downtown lakes in Wuhan city, Donghu Lake located in central city and Tangxunhu Lake located in suburbs, are taken as case study area. A direction change index (DCI) is proposed to evaluate the changes of a specific land use in different directions. The results reveal that two downtown lakes are undergoing rapid water body area decline from 1991 to 2013, with decline rate are -0.022 in Donghu watershed and -0.011 in Tangxunhu watershed. 68.26% and 62.50% of the reduced water body is occupied by built-up land in Donghu watershed and Tangxunhu watershed, respectively. According to DCI, the water body reduce is highly correlated with built-up land increase in all direction. Moreover, it is found that in the Donghu watershed the north-west part suffered significant water body area decline, which is close to central city. While in Tangxunhu watershed, the area of water body declined in north-west, south-west and north-east part, and the area obstructed from central city by the lake was suffering less water body area decline. It is concluded that the water body area of downtown lakes are highly affected by the process of urban sprawl, and the lakes in central districts trends to suffer higher descend than that of the downtown lake located in suburbs. Meanwhile, even for the same downtown lake, the area orientating and close to the central city may suffer more rapid decline than the area that does not orientate to the central city.

Hydrochemical determination of source water contributions to Lake Lungo and Lake Ripasottile (central Italy

Directory of Open Access Journals (Sweden)

Claire Archer

2016-12-01

Full Text Available Lake Lungo and Lake Ripasottile are two shallow (4-5 m lakes located in the Rieti Basin, central Italy, that have been described previously as surface outcroppings of the groundwater table. In this work, the two lakes as well as springs and rivers that represent their potential source waters are characterized physio-chemically and isotopically, using a combination of environmental tracers. Temperature and pH were measured and water samples were analyzed for alkalinity, major ion concentration, and stable isotope (δ2H, δ18O, δ13C of dissolved inorganic carbon, and δ34S and δ18O of sulfate composition.  Chemical data were also investigated in terms of local meteorological data (air temperature, precipitation to determine the sensitivity of lake parameters to changes in the surrounding environment. Groundwater represented by samples taken from Santa Susanna Spring was shown to be distinct with SO42- and Mg2+ content of 270 and 29 mg/L, respectively, and heavy sulfate isotopic composition (δ34S=15.2 ‰ and δ18O=10‰. Outflow from the Santa Susanna Spring enters Lake Ripasottile via a canal and both spring and lake water exhibits the same chemical distinctions and comparatively low seasonal variability. Major ion concentrations in Lake Lungo are similar to the Vicenna Riara Spring and are interpreted to represent the groundwater locally recharged within the plain. The δ13CDIC exhibit the same groupings as the other chemical parameters, providing supporting evidence of the source relationships. Lake Lungo exhibited exceptional ranges of δ13CDIC (±5 ‰ and δ2H, δ18O (±5 ‰ and ±7 ‰, respectively, attributed to sensitivity to seasonal changes. The hydrochemistry results, particularly major ion data, highlight how the two lakes, though geographically and morphologically similar, represent distinct hydrochemical facies. These data also show a different response in each lake to temperature and precipitation patterns in the basin that

Retailers test Ontario market

Energy Technology Data Exchange (ETDEWEB)

Kishewitsch, S.

2000-04-01

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.

Retailers test Ontario market

International Nuclear Information System (INIS)

Kishewitsch, S.

2000-01-01

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

Ontario hydro waste storage concepts and facilities

International Nuclear Information System (INIS)

Carter, T.J.; Mentes, G.A.

1976-01-01

Ontario Hydro presently operates 2,200 MWe of CANDU heavy water reactors with a further 11,000 MWe under design or construction. The annual quantities of low and medium level solid wastes expected to be produced at these stations are tabulated. In order to manage these wastes, Ontario Hydro established a Radioactive Waste Operations Site within the Bruce Nuclear Power Development located on Lake Huron about 250 km northwest of Toronto. The Waste Operations Site includes a 19-acre Storage Site plus a Radioactive Waste Volume Reduction Facility consisting of an incinerator and waste compactor. Ontario has in use or under construction both in-ground and above-ground storage facilities. In-ground facilities have been used for a number of years while the above-ground facilities are a more recent approach. Water, either in the form of precipitation, surface or subsurface water, presents the greatest concern with respect to confinement integrity and safe waste handling and storage operations

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

Science.gov (United States)

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

2015-01-01

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

Neotectonic investigations in southern Ontario: Prince Edward County. Phase I

International Nuclear Information System (INIS)

McFall, G.H.; Allam, A.

1989-03-01

This report summarizes the preliminary results of geological and geophysical investigations of possible neotectonic features in Prince Edward County, southern Ontario, made by the Ontario Geological Survey during 1988. Low magnitude seismic events indicative of contemporary stress relief occurred during 1987-88 near Salmon Point and Consecon (M 2.2). These events were located proximal to a major regional fault system crossing Lake Ontario and consisting of the Clarendon-Linden Fault System in New York State and the Salmon River-Picton fault systems in Ontario. Detailed observations were made of regional jointing orientations (predominantly 60 degrees and 125 degrees), erosion of surficial deposits adjacent to open fractures, a local fault displacement (post-glacially), dome structures located at Point Petre, and dissolution/karst terrains in the eastern part of the study area. Excavations of four pop-up structures indicate that three are classical pop-ups and one is atypical in structure. Level transects were conducted across complex structures in the eastern part of the study area. Detailed refraction seismic and resistivity surveys were conducted on pop-up and fault features. Preliminary results indicate that the Picton Fault is a complex zone of fractures with differing bedrock on each side. The central zone of the East Duck Pond pop-up is fractured and may contain variable amounts of water. Overturned and upright folds in the Consecon Quarry located outside of the primary research area were documented and found to be trending in a west-northwest to northwest direction. This fold orientation is compatible both with a glacial shove origin and with the present stress field orientations. Although glacial shove can produce overturned folds, it cannot form upright folds. A regional, tectonic deformation oriented northeasterly is therefore suggested as the causative mechanism

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...

Comparison of evaporation at two central Florida lakes, April 2005–November 2007

Science.gov (United States)

Swancar, Amy

2015-09-25

Evaporation from April 2005 through October 2007 at two central Florida lakes, one close to the Gulf of Mexico and one in the center of the peninsula, was 4.043 and 4.111 meters (m), respectively; evaporation for 2006 was 1.534 and 1.538 m, respectively. Although annual evaporation rates at the two lakes were similar, there were monthly differences between the two lakes because of changes in stored heat; the shallower Lake Calm (mean depth 3 m) stored less heat and exchanged heat more rapidly than the deeper Lake Starr (mean depth 5 m).

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)

Gibbons, J.

2002-06-01

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

Organic carbon accumulation and reactivity in central Swedish lakes during the Holocene

Science.gov (United States)

Chmiel, H.; Kokic, J.; Niggemann, J.; Dittmar, T.; Sobek, S.

2012-04-01

Sedimentation and burial of particulate organic carbon (POC), received from terrestrial sources and from lake internal primary production, are responsible for the progressive accumulation and long-term storage of organic matter in lake basins. For lakes in the boreal zone of central Sweden it can be presumed, that the onset of POC accumulation occurred during the early Holocene (˜8000 BP.) after the retreat of the Scandinavian ice sheet. In this study we investigated carbon mass accumulation rates (CMARs), as well as sources and reactivity of deposited organic material, for seven lakes in central Sweden (60°N, 15°E), in order to obtain a detailed temporal resolution of carbon burial and preservation in boreal lakes. Sediment long-cores were sampled in March 2011 from the ice, and CMARs were calculated from water contents, dry bulk densities, carbon contents and radiocarbon (14C) ages of the depth profiles. To indicate the sources of the organic material and characterize its diagenetic state, we determined carbon-nitrogen ratios (C/N) as well as amounts and compositions of lignin phenols. The transitions from organic rich sediment layers to glacial till deposits were found to be in sediment depths of ˜3 m in each lake. POC contents were on average highest (25-34 wt. % C), in small lakes (≤ 0.07 km2) and lowest (10-18 wt. % C) in the larger lakes (≥ 165 km2). The CMARs over the Holocene showed significant variations and were on average lower in the early Holocene, compared to recent accumulation rates. C/N values and the composition of lignin phenols further provided indications of important changes in organic matter source and reactivity over the Holocene. In summary, our data suggest that boreal lake sediments were a significantly stronger sink for organic carbon during the last ~150 years than during earlier periods of the Holocene.

Implications of climate change for water resources in the Great Lakes basin

International Nuclear Information System (INIS)

Clamen, M.

1990-01-01

Several authors have suggested the following impacts of global warming for the Great Lakes region. The average annual warming is predicted by one model to be ca 4.5 degree C, slightly more in winter and slightly less in summer. Annual precipitation is projected to increase by ca 8% for points in the central and western basin, but to decrease by 3-6% for the eastern basin. Basin snowpack could be reduced by up to 100% and the snow season shortened by 2-4 weeks, resulting in a reduction of more than 50% in available soil moisture. Buoyancy-driven turnovers of the water column on four of the six lakes may not occur at all. Presently the phenomena occurs twice per year on all the lakes. Ice formation would be greatly reduced. Maximum ice cover may decline from 72-0% for Lake Superior, 38-0% for Lake Michigan, 65-0% for Lake Huron, 90-50% for Lake Erie and 33-0% for Lake Ontario. Net basin supplies would be reduced probably in the range 15-25% below the current mean value. Possible responses include integrated studies and research, better and continually updated information, assessment of public policies in the U.S. and Canada, enhanced private planning efforts, and increased global cooperation

Mapping lake level changes using ICESat/GLAS satellite laser altimetry data: a case study in arid regions of central Asia

Science.gov (United States)

Li, JunLi; Fang, Hui; Yang, Liao

2011-12-01

Lakes in arid regions of Central Asia act as essential components of regional water cycles, providing sparse but valuable water resource for the fragile ecological environments and human lives. Lakes in Central Asia are sensitive to climate change and human activities, and great changes have been found since 1960s. Mapping and monitoring these inland lakes would improve our understanding of mechanism of lake dynamics and climatic impacts. ICESat/GLAS satellite laser altimetry provides an efficient tool of continuously measuring lake levels in these poorly surveyed remote areas. An automated mapping scheme of lake level changes is developed based on GLAS altimetry products, and the spatial and temporal characteristics of 9 typical lakes in Central Asia are analyzed to validate the level accuracies. The results show that ICESat/GLAS has a good performance of lake level monitoring, whose patterns of level changes are the same as those of field observation, and the max differences between GLAS and field data is 3cm. Based on the results, it is obvious that alpine lakes are increasing greatly in lake levels during 2003-2009 due to climate change, while open lakes with dams and plain endorheic lakes decrease dramatically in water levels due to human activities, which reveals the overexploitation of water resource in Central Asia.

Geology, geochemistry, and geochronology of the East Bay gold trend, Red Lake, Ontario, Canada

Science.gov (United States)

Gallagher, Shaun; Camacho, Alfredo; Fayek, Mostafa; Epp, Mark; Spell, Terry L.; Armstrong, Richard

2018-01-01

The Red Lake greenstone belt is situated in northwestern Ontario within the Uchi Subprovince, Superior Province. Most gold deposits therein are associated with major deformation corridors; the east-west oriented "Mine trend" hosts most of the large deposits and the northeast-southwest "East Bay trend" hosts several small deposits and showings. Gold along the East Bay trend typically occurs in quartz replacement veins that were emplaced into pre-existing quartz-carbonate veins. Gold can occur as free gold or along vein margins associated with pyrite and pyrrhotite. Most primary fluid inclusions, preserved in relatively undeformed portions of veins, are carbonaceous with lesser quantities of aqueous inclusions. The average homogenization temperature of aqueous fluids is 250 °C; however, the abundance of three-phase inclusions, variation in liquid-vapor ratios, and a wide range in homogenization temperatures indicate that immiscibility, effervescence, and fluid mixing are mechanisms associated with gold deposition. The age ( 2550 Ma) of alteration minerals in the Abino area is considerably younger (by 100 Myr) than alteration minerals in other deposits in the Red Lake district, indicating that the mineralizing fluid history was more protracted than previously thought. Along the East Bay trend, barren veins generally have lower δ18OVSMOW values (0.0 to 8.5‰) relative to auriferous veins (9.6 and 13.1‰). Consequently, the oxygen isotopic composition of quartz could be used as a vector for gold mineralization. The genetic model for the East Bay trend involves several stages of vein formation. Auriferous veins formed near the upper boundary of the mesozonal regime (depth of 5-6 km).

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

International Nuclear Information System (INIS)

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

2016-01-01

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 ("2"2"6Ra, "2"1"0Pb and "2"1"0Po) as well as anthropogenic radionuclides ("1"3"4Cs and "1"3"7Cs) were measured. This study confirmed that "2"1"0Po is the dominant contributor to radiation doses resulting from fish consumption. While concentrations of "2"1"0Pb and "2"2"6Ra were below conventional detection limits, "2"1"0Po 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 "1"3"4Cs. An average "1"3"7Cs 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 "1"3"7Cs 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. - Highlights: • "2"1"0Po is the dominant radionuclide measured in a total of 125 fish samples. The average activity concentration was 1.5 Bq/kg fresh weight (fw). • Activity concentration of "2"1"0Po in fish showed a negative dependency on fish size. • While an average "1"3"7Cs level of 6.1 Bq/kg fw was observed, none of the fish samples analysed in this study contained any detectable

Magnetic and gravity studies of Mono Lake, east-central, California

Science.gov (United States)

Athens, Noah D.; Ponce, David A.; Jayko, Angela S.; Miller, Matt; McEvoy, Bobby; Marcaida, Mae; Mangan, Margaret T.; Wilkinson, Stuart K.; McClain, James S.; Chuchel, Bruce A.; Denton, Kevin M.

2014-01-01

From August 26 to September 5, 2011, the U.S. Geological Survey (USGS) collected more than 600 line-kilometers of shipborne magnetic data on Mono Lake, 20 line-kilometers of ground magnetic data on Paoha Island, 50 gravity stations on Paoha and Negit Islands, and 28 rock samples on Paoha and Negit Islands, in east-central California. Magnetic and gravity investigations were undertaken in Mono Lake to study regional crustal structures and to aid in understanding the geologic framework, in particular regarding potential geothermal resources and volcanic hazards throughout Mono Basin. Furthermore, shipborne magnetic data illuminate local structures in the upper crust beneath Mono Lake where geologic exposure is absent. Magnetic and gravity methods, which sense contrasting physical properties of the subsurface, are ideal for studying Mono Lake. Exposed rock units surrounding Mono Lake consist mainly of Quaternary alluvium, lacustrine sediment, aeolian deposits, basalt, and Paleozoic granitic and metasedimentary rocks (Bailey, 1989). At Black Point, on the northwest shore of Mono Lake, there is a mafic cinder cone that was produced by a subaqueous eruption around 13.3 ka. Within Mono Lake there are several small dacite cinder cones and flows, forming Negit Island and part of Paoha Island, which also host deposits of Quaternary lacustrine sediments. The typical density and magnetic properties of young volcanic rocks contrast with those of the lacustrine sediment, enabling us to map their subsurface extent.

An assessment of the environmental benefits of demand management for the province of Ontario

International Nuclear Information System (INIS)

Plagiannakos, T.; Fordyce, A.; Boone, C.; Gooder, B.; Camacho, F.

1993-01-01

This study focused on the environmental impacts of fossil-fired generation that is expected to be displaced by electrical efficiency improvement programs and higher efficiency standards in the province on Ontario by the year 2000. Air emission dispersions were modelled by generating station. The impacts of air emission reductions on human mortality, human morbidity, building materials, agricultural crops, forests and lakes and fisheries were quantified using dose-response functions taken from the literature or estimated for the province of Ontario. Environmental impacts were monetized using cost data specific to Ontario. The final outcome was an estimate of the environmental benefits associated with emission reductions in fossil-fuelled power plants due to efficiency improvements in electricity use in the province of Ontario. (author). 7 refs., 4 tabs

Climate change impacts: an Ontario perspective

International Nuclear Information System (INIS)

Mortsch, L.

1995-11-01

Significant changes in the climate system which are likely to affect biophysical, social and economic systems in various ways, were discussed. Trends in greenhouse gas levels show that during the 20. century, human activity has changed the make-up of the atmosphere and its greenhouse effect properties. A pilot study on the impacts of climate change identified changes in the water regime such as declines in net basin supply, lake levels and outflows, as important concerns. These changes would have impacts on water quality, wetlands, municipal water supply, hydroelectric power generation, commercial shipping, tourism and recreation, and to a lesser extent, on food productions. Climate impact assessments suggest that world conditions will change significantly as a result. Those with less resources are likely to be most affected by climate change, and the impacts on other regions of the world will be more significant to Ontario than the direct impacts on Ontario itself. In an effort to keep pace with global changes, Ontario will have to limit emissions, conduct research in innovative technology and develop greater awareness of the risk of climate change. refs., tabs., figs

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

International Nuclear Information System (INIS)

Freihammer, Till; Chaput, Barb; Vandergaast, Gary; Arey, Jimi

2013-01-01

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

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

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.

Phytoplankton from Lake Magelungen, Central Sweden 1960-1963

Energy Technology Data Exchange (ETDEWEB)

Willen, Torbjoern [Inst. of Limnology, Univ of Uppsala, Uppsala (Sweden)

1966-03-15

The investigation of the qualitative and quantitative composition of phytoplankton in Lake Magelungen, Central Sweden, was carried out over a period of three years to illustrate the conditions before the release of waste water from the Aagesta Heat and Power Station began. Vertical sampling series were taken about once a month and samples from three different stations (named MA, MOB and MH) in the lake were analysed and compared. Most importance was laid on the quantitative composition and the differences in total volumes between the different stations. Highest volume values were always recorded in late spring and in summer. Two algal groups predominated every year, viz. chlorophytes and cyanophytes. After a moderate spring outburst caused by diatoms (Stephanodiscus, Synedra and Asterionella) peak volume values of chlorophytes were recorded in June and July. Predominating genera were Scenedesmus, Coelastrum and Pediastrum. The chlorophyte maximum was always followed by an immense development of cyanophytes (Anabaena, Aphanizomenon and Microcystis). The diatoms were well developed only during short periods, the chrysophyceans were of little significance as were all other algal groups. A marked difference existed between the Station MOB compared with the two other stations. The water at Station MOB was more polluted and several algal genera indicating the pollution were recorded. Both chlorophytes and cyanophytes were often developed in very great quantities at this station. The total volumes of phytoplankton in Lake Magelungen already are very high and the lake is to be considered as highly eutrophic. It is very possible that changes as to further additions of nutritional elements or/and changes in the thermal balance will increase the algal populations and accelerate the normal development of the lake.

Phytoplankton from Lake Magelungen, Central Sweden 1960-1963

International Nuclear Information System (INIS)

Willen, Torbjoern

1966-03-01

The investigation of the qualitative and quantitative composition of phytoplankton in Lake Magelungen, Central Sweden, was carried out over a period of three years to illustrate the conditions before the release of waste water from the Aagesta Heat and Power Station began. Vertical sampling series were taken about once a month and samples from three different stations (named MA, MOB and MH) in the lake were analysed and compared. Most importance was laid on the quantitative composition and the differences in total volumes between the different stations. Highest volume values were always recorded in late spring and in summer. Two algal groups predominated every year, viz. chlorophytes and cyanophytes. After a moderate spring outburst caused by diatoms (Stephanodiscus, Synedra and Asterionella) peak volume values of chlorophytes were recorded in June and July. Predominating genera were Scenedesmus, Coelastrum and Pediastrum. The chlorophyte maximum was always followed by an immense development of cyanophytes (Anabaena, Aphanizomenon and Microcystis). The diatoms were well developed only during short periods, the chrysophyceans were of little significance as were all other algal groups. A marked difference existed between the Station MOB compared with the two other stations. The water at Station MOB was more polluted and several algal genera indicating the pollution were recorded. Both chlorophytes and cyanophytes were often developed in very great quantities at this station. The total volumes of phytoplankton in Lake Magelungen already are very high and the lake is to be considered as highly eutrophic. It is very possible that changes as to further additions of nutritional elements or/and changes in the thermal balance will increase the algal populations and accelerate the normal development of the lake

The luminescence dating chronology of a deep core from Bosten Lake (NW China) in arid central Asia reveals lake evolution over the last 220 ka

DEFF Research Database (Denmark)

Li, Guoqiang; Duan, Yanwu; Huang, Xiaozhong

2016-01-01

The lacustrine deposits of lakes in arid central Asia (ACA) potentially record palaeoclimatic changes on orbital and suborbital time scales, but such changes are still poorly understood due to the lack of reliable chronologies. Bosten Lake, the largest freshwater inland lake in China, is located...... in the southern Tianshan Mountains in central ACA. A 51.6-m-deep lacustrine succession was retrieved from the lake and 30 samples from the succession were used for luminescence dating to establish a chronology based on multi-grain quartz OSL and K-feldspar post-IR IRSL (pIRIR290) dating. Quartz OSL ages were only....... A stable deep lake occurred at c. 220, 210–180, c. 165, 70–60, 40–30 and 20–5 ka, while shallow levels occurred at c. 215, 180–165, 100–70, 60–40 and 30–20 ka. Bosten Lake levels decreased by at least ~29 m and possibly the lake even dried up between c. 160 and c. 100 ka. We suggest that the water...

Prevalence of antibiotic resistance genes in bacterial communities associated with Cladophora glomerata mats along the nearshore of Lake Ontario.

Science.gov (United States)

Ibsen, Michael; Fernando, Dinesh M; Kumar, Ayush; Kirkwood, Andrea E

2017-05-01

The alga Cladophora glomerata can erupt in nuisance blooms throughout the lower Great Lakes. Since bacterial abundance increases with the emergence and decay of Cladophora, we investigated the prevalence of antibiotic resistance (ABR) in Cladophora-associated bacterial communities up-gradient and down-gradient from a large sewage treatment plant (STP) on Lake Ontario. Although STPs are well-known sources of ABR, we also expected detectable ABR from up-gradient wetland communities, since they receive surface run-off from urban and agricultural sources. Statistically significant differences in aquatic bacterial abundance and ABR were found between down-gradient beach samples and up-gradient coastal wetland samples (ANOVA, Holm-Sidak test, p Cladophora sampled near the STP had the highest bacterial densities overall, including on ampicillin- and vancomycin-treated plates. However, quantitative polymerase chain reaction analysis of the ABR genes ampC, tetA, tetB, and vanA from environmental communities showed a different pattern. Some of the highest ABR gene levels occurred at the 2 coastal wetland sites (vanA). Overall, bacterial ABR profiles from environmental samples were distinguishable between living and decaying Cladophora, inferring that Cladophora may control bacterial ABR depending on its life-cycle stage. Our results also show how spatially and temporally dynamic ABR is in nearshore aquatic bacteria, which warrants further research.

Forecasting cyanobacteria dominance in Canadian temperate lakes.

Science.gov (United States)

Persaud, Anurani D; Paterson, Andrew M; Dillon, Peter J; Winter, Jennifer G; Palmer, Michelle; Somers, Keith M

2015-03-15

Predictive models based on broad scale, spatial surveys typically identify nutrients and climate as the most important predictors of cyanobacteria abundance; however these models generally have low predictive power because at smaller geographic scales numerous other factors may be equally or more important. At the lake level, for example, the ability to forecast cyanobacteria dominance is of tremendous value to lake managers as they can use such models to communicate exposure risks associated with recreational and drinking water use, and possible exposure to algal toxins, in advance of bloom occurrence. We used detailed algal, limnological and meteorological data from two temperate lakes in south-central Ontario, Canada to determine the factors that are closely linked to cyanobacteria dominance, and to develop easy to use models to forecast cyanobacteria biovolume. For Brandy Lake (BL), the strongest and most parsimonious model for forecasting % cyanobacteria biovolume (% CB) included water column stability, hypolimnetic TP, and % cyanobacteria biovolume two weeks prior. For Three Mile Lake (TML), the best model for forecasting % CB included water column stability, hypolimnetic TP concentration, and 7-d mean wind speed. The models for forecasting % CB in BL and TML are fundamentally different in their lag periods (BL = lag 1 model and TML = lag 2 model) and in some predictor variables despite the close proximity of the study lakes. We speculate that three main factors (nutrient concentrations, water transparency and lake morphometry) may have contributed to differences in the models developed, and may account for variation observed in models derived from large spatial surveys. Our results illustrate that while forecast models can be developed to determine when cyanobacteria will dominate within two temperate lakes, the models require detailed, lake-specific calibration to be effective as risk-management tools. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

Science.gov (United States)

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

2017-04-01

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

Tourism climatology for camping: a case study of two Ontario parks (Canada)

Science.gov (United States)

Hewer, Micah J.; Scott, Daniel; Gough, William A.

2015-08-01

Climate and weather act as central motivators for the travel decisions of tourists. Due to their seasonality, these factors determine the availability and quality of certain outdoor recreational activities. Park visitation in Ontario, Canada, has been identified as a weather sensitive tourism and recreation activity. This study used a survey-based approach to identify and compare stated weather preferences and thresholds, as well as weather-related decision-making for campers at two provincial parks in Ontario, Canada. The two parks were selected for differing physical and environmental characteristics (forested lake versus coastal beach). Statistically significant differences were detected between the two parks in relation to the importance of weather and weather-based decision-making. Specific temperatures that were considered ideal and thresholds that were too cool and too warm were identified for both parks, both during the day and the night. Heavy rain and strong winds were the most influential factors in weather-related decision-making and on-site behavioural adaptations. Beach campers placed greater importance on the absence of rain and the presence of comfortable temperatures compared to forest campers. In addition, beach campers were more likely to leave the park early due to incremental weather changes. The results of this study suggest that beach campers are more sensitive to weather than forest campers.

VITELLOGENIN GENE EXPRESSION IN FATHEAD MINNOWS EXPOSED TO EE2 IN A WHOLE LAKE DOSING EXPERIMENT

Science.gov (United States)

A whole-lake endocrine disruption experiment was conducted by Fisheries and Oceans Canada at the Experimental Lakes Area (ELA), northwestern Ontario in 2001 and 2002. This experiment examined population, organism, biochemical and cellular-level effects in lake trout, white sucke...

Classification of the ecological status of volcanic lakes in Central Italy

Directory of Open Access Journals (Sweden)

Daria VAGAGGINI

2003-09-01

Full Text Available A synthesis is made of biological data collected in the last three decades on five volcanic lakes in Central Italy with the aim of evaluating their environmental status by means of biological parameters related to zooplankton, littoral and profundal zoobenthos frequently used to detect water quality changes in lakes. A number of bioindicators and bioindices were selected for this purpose, as far as possible following an integrated approach using information drawn from physical and chemical variables. Our results allowed the lakes to be classified according to their biological quality level, which proved to be in good agreement with physical and chemical diagnoses. Lake Bracciano exhibited the best environmental quality, due to the presence of a ring waste water collecting system, to its large size and depth, and to its strong hydrodynamism. Lake Martignano followed, with some symptoms of stress in the hypolimnion due to a marked summer deoxygenation. Oxygen depletion in the profundal characterized also Lake Vico, which showed a mesotrophic condition in the sixties, and 20 years later now shows clear signs of increased trophy (meso-eutrophy. Lake Albano seemed meso-eutrophic with total absence of fauna below a depth of 120 m due to a meromictic status. Finally Lake Nemi, exposed to domestic wastes in the 70s, suffered a heavy eutrophication with dramatic algal blooms and fish kills. Following the diversion of discharges that occurred in the early 90s, today this lake is characterized by the partial improvement of many ecological features. The need for integration between physical and chemical analyses and biological data in order to obtain a reliable evaluation of lake environmental quality is stressed, especially as far as routine implementation in managing and recovery procedures is concerned.

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

International Nuclear Information System (INIS)

Schindler, Michael; Kamber, Balz S.

2013-01-01

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, 137 Cs 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 (PO 4 ) 3− , (AsO 4 ) 4− , and (MoO 4 ) 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

Metal partitioning and uptake in central Ontario forests

International Nuclear Information System (INIS)

Watmough, Shaun A.; Dillon, Peter J.; Epova, Ekaterina N.

2005-01-01

Evaluation of the potential environmental risk posed by metals depends to a great extent on modeling the fate and mobility of metals with soil-solution partitioning coefficients (K d ). However, the effect of biological cycling on metal partitioning is rarely considered in standard risk assessments. We determined soil-solution partitioning coefficients for 5 metals (Cd, Zn, Pb, Co and Ni) at 46 forested sites that border the Precambrian Shield in central Ontario, where soil pH aq varied from 3.9 to 8.1. Foliage from the dominant tree species and forest floor samples were also collected from each site to compare their metal levels with K d predictions. Analogous to other studies, log K d values for all metals were predicted by empirical linear regression with soil pH (r 2 = 0.66-0.72), demonstrating that metal partitioning between soil and soil solution can be reliably predicted for relatively unpolluted forest mineral soils by soil pH. In contrast, whereas the so-called bioavailable water-soluble metal fraction could be predicted from soil pH, metal concentrations in foliage and the forest floor at each site were not consistently related to pH. Risk assessment of metals should take into account the role of biota in metal cycling and partitioning in forests, particularly if metal bio-accumulation and chronic toxicity in the food chain, rather than metal mobility in soils, are of primary concern. - Metal cycling by plants should be considered in risk assessment studies

Radiochemical tools at the experimental lakes area (ELA) in Ontario, Canada

International Nuclear Information System (INIS)

Pfitzner, J.; Brunskill, G.

1998-01-01

Full text: For over 20 years, Canadian research scientists have used radiochemical tracers added to remote and pristine lakes to study physical, chemical, and biological processes that could not be easily quantified by other methods. Lakes have also been manipulated by experimentally altering the hydrological cycle, chemical composition, and species of fish in selected lakes, and using companion lakes as controls. Varying additions of organic carbon, N, and P have been done, and the exchange rate of carbon dioxide between the atmosphere and water was estimated using radon evasion rates from radium spikes in the lake water. Multinuclide spikes were done to follow the path of mine waste elements through the food chain and sediment accumulation. Lakes were experimentally acidified with HCl and HNO 3 and H 2 SO 4 to simulate acid rain, and to study natural buffering capacity of the hydrological cycle. Some of this research has been used to legislate pollution control in the St. Laurence Great Lakes and across Canada and USA. ELA research team spirit has survived several forest fires, bear attacks on the kitchen, massive cut-backs in funding and reduction in staff of Fisheries and Ocean Canada

Calcium and sodium as regulators of the recovery of four Daphnia species along a gradient of metal and base cations in metal contaminated lakes in Sudbury, Ontario, Canada

Directory of Open Access Journals (Sweden)

Martha Patricia Celis-Salgado

2016-04-01

Full Text Available Smelting of sulphur-rich metallic ores in Sudbury, Ontario, Canada, has caused acidification and metal contamination of thousands of lakes in the region. Recent reductions in smelter emissions have resulted in much ecological recovery, but the recovery of Daphnia species has been poor. To determine if Cu and Ni toxicity could explain differences in daphniid recovery among lakes, we compared results of 14 d static with renewal bioassays in waters from Blue Chalk Lake, an uncontaminated reference lake 200 km from Sudbury, and from five Sudbury lakes ranging in distance from the smelters and varying in metal and cation concentrations. We spiked Blue Chalk Lake water with Cu and Ni to levels resembling those of the Sudbury lakes and also tested the lake waters for toxicity. Survival of Daphnia pulex, D. pulicaria and D. mendotae decreased monotonically with increasing metal concentrations in the spiked Blue Chalk Lake treatments, falling from 90% in the controls to 0% at the two highest Cu and Ni levels, reflecting levels of Middle and Hannah lakes. In contrast, survival in waters collected from the actual Sudbury lakes did not monotonically track their total metal concentrations. Rather, survival fell to 0% in Clearwater Lake water, a lake with intermediate metal contamination (8.9 and 79.9 μg L–1 of Cu and Ni, respectively vs 70-100% in the other lakes. We performed an additional assay with Clearwater Lake waters increasing its Ca and Na concentrations, singly and in combination to levels that reflected the levels in Middle Lake. The survival of the four daphniid species increased from 0% up to 80-100% with added Ca and from 0% to 60-90% with added Na. Lipid-ovarian indices had a similar trend to survival for D. mendotae and D. pulicaria in Bioassay 1, varying with the cation concentrations in the lakes for the daphniids in Bioassay 2. The bioassays results imply that regional recovery patterns of daphniids in Sudbury lakes cannot be understood

First inventory of optical lake types in the permafrost landscapes of the central Lena River Delta and central Yamal - case studies of Coloured Dissolved Organic Matter (cDOM) and turbidity regimes

Science.gov (United States)

Heim, Birgit; Bartsch, Annett; Dvornikov, Yuri; Leibman, Marina; Eulenburg, Antje; Morgenstern, Anne; Boike, Julia; Widhalm, Barbara; Fedorova, Irina; Chetverova, Antonina

2015-04-01

We provide a first satellite-based inventory of optical lake types in the permafrost landscapes of the central Lena River Delta and central Yamal using multi-sensor satellite data. Within our thematic network between our groups we seek to investigate how we may link: • multi-sensor remote sensing analysis (optical and radar) • tachymmetrical and satellite-based stereographical analysis • geochemical and hydrodynamical ground investigations in the thermokarst- and thermoerosional-influenced landscape types in the central Lena Delta and the Yamal region in Siberia. We are investigating the turbidity regimes of the lakes and the catchment characteristics (vegetation, geomorphology, topography) using satellite-derived information from optical and radar sensors. For some of the lakes in Yamal and the central Lena River Delta we were able to sample for Dissolved Organic Carbon, DOC, and coloured dissolved organic matter, cDOM (the absorbing fraction of the DOC pool). The sediment sources for turbidity spatial patterns are provided by the large subaquatic sedimentary banks and lake cliffs. The cDOM regimes influence the transparency of the different lake types. However, turbidity seems to play the dominant role in providing the water colour of thermokarst lake types.

Origin and evolution of Sariñena Lake (central Ebro Basin): A piping-based model

Science.gov (United States)

Castañeda, Carmen; Javier Gracia, F.; Rodríguez-Ochoa, Rafael; Zarroca, Mario; Roqué, Carles; Linares, Rogelio; Desir, Gloria

2017-08-01

The origin and nature of the numerous lakes in the central Ebro Basin have been interpreted according to the prevailing arid or semiarid conditions, the easily-eroded materials and the solubility of the gypsum- and/or carbonate-rich Tertiary/Cenozoic substratum, involving important dissolution (karstic) and/or aeolian deflation. However, the origin of Sariñena Lake, the largest in the central Ebro Basin, remains unknown since the typical lake-generating processes in the region are not applicable. This work provides significant clues to the genesis and evolution of Sariñena Lake in a regional context. The combination of geomorphological mapping and high resolution LiDAR data together with sedimentological observations, the characterisation of soils and sediments around the lake, and the application of high-resolution geophysical techniques suggest that piping is the major genetic process driving the evolution of the Sariñena depression and lake. Field evidence demonstrates that piping is, at present, the most important erosive process in the region, generating significant collapse and surface lowering. Sariñena Lake is located within a deep endorheic depression excavated from Na-rich Tertiary materials. This work hypothesises that once an early, fluvially-originated palustrine area had developed, the progressive lowering of the regional water table linked to regional fluvial incision favoured the establishment of a hydrological gradient high enough to trigger piping processes within the claystones and siltstones underlying the original palustrine area. The Quaternary evolution of the Sariñena lacustrine basin was then controlled by successive water table fluctuations, linked to different phases of incision and alluvial deposition in the surrounding fluvial systems. All the evidence supporting a piping-related origin for this lake, together with examples of lakes generated by similar processes in different contexts, is used to propose a new genetic type of

Avian metapneumovirus subtype C in Wild Waterfowl in Ontario, Canada.

Science.gov (United States)

Jardine, C M; Parmley, E J; Buchanan, T; Nituch, L; Ojkic, D

2018-02-18

Avian metapneumovirus (aMPV) is an emerging poultry pathogen that has a significant economic impact on poultry production worldwide. The geographic range of the virus continues to expand, and wild birds have been implicated as reservoirs of aMPV that have the potential to spread the virus over long distances. Our objective was to determine the apparent prevalence of aMPV subtype C in wild waterfowl in Ontario, Canada. Wild waterfowl were captured in August and September, 2016 as part of routine migratory waterfowl population monitoring by the Ontario Ministry of Natural Resources and Forestry. Oropharyngeal and cloacal swabs were collected from each bird and placed together for aMPV testing using real-time RT-PCR. A total of 374 live wild birds from 23 lakes were sampled and tested for aMPV. Among all ducks tested, 84 (22%) were positive for aMPV. The proportion of samples that tested positive ranged from 0% in ring-necked ducks (Aythya collaris) and green-winged teal (Anas carolinensis) to 44% (8 of 18) in American black ducks (A. rubripes). Waterfowl positive for aMPV were found at 14 of 23 lakes in the study area and the percent positive at these 14 lakes ranged between 5% and 84%. Although subtype C aMPV has been detected in a variety of wild birds in North America, this is the first report of aMPV in wild ducks in Ontario, Canada. The high apparent prevalence, particularly in mallards and American black ducks (37 and 44%, respectively), suggests that these species may be important reservoirs of aMPV. Given the potential impact of aMPV on domestic poultry and the potential role of wild birds as reservoirs of the virus, further investigation of the geographic distribution, risk factors associated with aMPV carriage in wild waterfowl and potential role of other birds in the epidemiology of aMPV in Canada is warranted. © 2018 Blackwell Verlag GmbH.

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.

Polymethylene-interrupted fatty acids: Biomarkers for native and exotic mussels in the Laurentian Great Lakes

Science.gov (United States)

Mezek, Tadej; Sverko, Ed; Ruddy, Martina D.; Zaruk, Donna; Capretta, Alfredo; Hebert, Craig E.; Fisk, Aaron T.; McGoldrick, Daryl J.; Newton, Teresa J.; Sutton, Trent M.; Koops, Marten A.; Muir, Andrew M.; Johnson, Timothy B.; Ebener, Mark P.; Arts, Michael T.

2011-01-01

Freshwater organisms synthesize a wide variety of fatty acids (FAs); however, the ability to synthesize and/or subsequently modify a particular FA is not universal, making it possible to use certain FAs as biomarkers. Herein we document the occurrence of unusual FAs (polymethylene-interrupted fatty acids; PMI-FAs) in select freshwater organisms in the Laurentian Great Lakes. We did not detect PMI-FAs in: (a) natural seston from Lake Erie and Hamilton Harbor (Lake Ontario), (b) various species of laboratory-cultured algae including a green alga (Scenedesmus obliquus), two cyanobacteria (Aphanizomenon flos-aquae and Synechococystis sp.), two diatoms (Asterionella formosa, Diatoma elongatum) and a chrysophyte (Dinobryon cylindricum) or, (c) zooplankton (Daphnia spp., calanoid or cyclopoid copepods) from Lake Ontario, suggesting that PMI-FAs are not substantively incorporated into consumers at the phytoplankton–zooplankton interface. However, these unusual FAs comprised 4-6% of total fatty acids (on a dry tissue weight basis) of native fat mucket (Lampsilis siliquoidea) and plain pocketbook (L. cardium) mussels and in invasive zebra (Dreissena polymorpha) and quagga (D. bugensis) mussels. We were able to clearly partition Great Lakes' mussels into three separate groups (zebra, quagga, and native mussels) based solely on their PMI-FA profiles. We also provide evidence for the trophic transfer of PMI-FAs from mussels to various fishes in Lakes Ontario and Michigan, further underlining the potential usefulness of PMI-FAs for tracking the dietary contribution of mollusks in food web and contaminant-fate studies.

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.

Hydroelectric project EA's [environmental assessments]: The Magpie development in northern Ontario

International Nuclear Information System (INIS)

Ashwood, K.

1992-01-01

Great Lakes Power recently constructed a hydroelectric plant on the Magpie River near Wawa, Ontario. The project involved three main elements: construction of a 33 m high dam, a 15.5 MW power station, and a spillway at Steephill Falls; construction of a 3.5 m high overflow weir just above the crest of scenic Magpie Falls, creating a head pond to supply a 15 MW power plant; and construction of a weir and 15 MW power plant at Mission Falls. Although this was a private development and therefore not automatically subject to Ontario's Environmental Assessment Act, Great Lakes Power decided to conform with the act's requirements and undertook a comprehensive environmental assessment (EA). Environmental issues were focused on changes in hydrology and water quality, impacts on fisheries and natural resources, slope stability and erosion, socioeconomic impacts, impacts on heritage resources, and impacts on tourism and recreation. The project was approved subject to conditions which included implementation of mitigation and monitoring requirements outlined in the EA document. Environmental specialists worked closely with the engineers at the detailed design stage of the project, resulting in modifications to the preliminary design to minimize environmental impacts

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.

Integrated hazard assessment of Cirenmaco glacial lake in Zhangzangbo valley, Central Himalayas

Science.gov (United States)

Wang, Weicai; Gao, Yang; Iribarren Anacona, Pablo; Lei, Yanbin; Xiang, Yang; Zhang, Guoqing; Li, Shenghai; Lu, Anxin

2018-04-01

Glacial lake outburst floods (GLOFs) have recently become one of the primary natural hazards in the Himalayas. There is therefore an urgent need to assess GLOF hazards in the region. Cirenmaco, a moraine-dammed lake located in the upstream portion of Zhangzangbo valley, Central Himalayas, has received public attention after its damaging 1981 outburst flood. Here, by combining remote sensing methods, bathymetric survey and 2D hydraulic modeling, we assessed the hazard posed by Cirenmaco in its current status. Inter-annual variation of Cirenmaco lake area indicates a rapid lake expansion from 0.10 ± 0.08 km2 in 1988 to 0.39 ± 0.04 km2 in 2013. Bathymetric survey shows the maximum water depth of the lake in 2012 was 115 ± 2 m and the lake volume was calculated to be 1.8 × 107 m3. Field geomorphic analysis shows that Cirenmaco glacial lake is prone to GLOFs as mass movements and ice and snow avalanches can impact the lake and the melting of the dead ice in the moraine can lower the dam level. HEC-RAS 2D model was then used to simulate moraine dam failure of the Cirenmaco and assess GLOF impacts downstream. Reconstruction of Cirenmaco 1981 GLOF shows that HEC-RAS can produce reasonable flood extent and water depth, thus demonstrate its ability to effectively model complex GLOFs. GLOF modeling results presented can be used as a basis for the implementation of disaster prevention and mitigation measures. As a case study, this work shows how we can integrate different methods to GLOF hazard assessment.

Cycling of acid and base cations in deciduous stands of Huntington Forest, New York, and Turkey Lakes, Ontario

Energy Technology Data Exchange (ETDEWEB)

Foster, N W; Morrison, I K [Forestry Canada, Sault Ste. Marie, ON (Canada); Mitchell, M J [State Univ. of New York, Syracuse, NY (USA); Shepard, J P [National Council of the Paper Industry for Air and Stream Improvement, Gainesville, FL (USA)

1992-01-01

Annual nutrient fluxes within two forests exposed to acidic deposition were compared for a 1-year period. Calcium (Ca{sup 2+}) was the dominant cation in throughfall and soil solutions from tolerant hardwood dominated Spodosols (Podzols) at both Huntington Forest (HF), New York, and the Turkey Lakes watershed (TLW), Ontario. There was a net annual export of Ca{sup 2+} and Mg{sup 2+} from the TLW soil, whereas base cation inputs in precipitation equalled outputs at HF. In 1986, leaching losses of base cations were five times greater at TLW than at HF. A higher percentage of the base cation reserves was leached from the soil at TLW (5%) than at HF (1%). Relative to throughfall, aluminum concentrations increased in forest-floor and mineral-soil solutions, especially at HF. The TLW soil appears more sensitive to soil acidification. Deposited atmospheric acidity, however, was small in comparison with native soil acidity (total and exchangeable) and the reserves of base cations in each soil. Soil acidity and base saturation, therefore, are likely only to change slowly. 57 refs., 1 fig., 5 tabs.

The algal growth-limiting nutrient of lakes located at Mexico’s Mesa Central

Directory of Open Access Journals (Sweden)

Fernando W. Bernal-Brooks

2016-03-01

Full Text Available This paper reports on the algal growth-limiting nutrients of five lakes located on Mexico’s Mesa Central - a topic poorly known in the regional limnology of Mexico. The five case studies involved three contiguous watersheds of Michoacán State and provided a trophic state variation from mesotrophic to hypereutrophic; the case studies included Lakes Zirahuén, Pátzcuaro, Teremendo, Cuitzeo and the Cointzio Reservoir. The fieldwork involved the collection of physical and chemical data (including nutrients from each case study during the dry and rainy seasons of 2010. Additionally, water samples (1 L were obtained and filtered (0.45 µm in the laboratory to keep the nutrient content available for bioassays. The chemical analyses suggested a phosphorus (P limitation in the Cointzio Reservoir, Lake Teremendo and Lake Zirahuén relative to an N:P>16:1. There was a nitrogen (N limitation at three sampling stations of Lake Pátzcuaro, with an N:P<16:1. As result of the bioassays conducted in July 2012, the Cointzio Reservoir and Lake Teremendo appeared to be P-limited and Lake Pátzcuaro appeared to be N-limited at three sampling stations. Lake Zirahuén showed seasonal variation, with an N limitation during the dry season and a P limitation during the wet season. Those cases with similar results from both methods confirmed the limiting nutrient identification. Lake Cuitzeo, Lake Zirahuén (dry season, and the shallowest sampling station in Lake Pátzcuaro produced unclear results because of divergent outcomes. In terms of the algal growth potential, the Cointzio Reservoir remained unaltered from one season to the next. However, for most of the lakes (with the exception of Lake Pátzcuaro sites 2 and 4, the rainy season provided a dilution effect. Effective lake management depends on a clear recognition of such elements that are in control of the aquatic productivity. In the area of Michoacán, both N and P may act as limiting nutrients.

Adapting to climate variability and change in Ontario : volume 4 of the Canada country study : climate impacts and adaptation

Energy Technology Data Exchange (ETDEWEB)

Smith, J.; Lavender, B. [Smith and Lavender Envrironmental Consultants, ON (Canada); Auld, H.; Broadhurst, D.; Bullock, T. [Environment Canada, Ottawa, ON (Canada). Ontario Region

1998-03-01

An assessment of how climate change will affect Ontario over the next century, including its social, biological and economic environment, is presented. The most significant impacts are expected to result from changes in precipitation patterns, in soil moisture, and in greater intensity and frequency of extreme weather events. Some of the major impacts of changing climate discussed in this volume include: (1) more pollution episodes, (2) increased heat stress, (3) lowering of average water levels of the Great Lakes, (4) changes in the hydrologic cycle which could result in variability of water supply for hydroelectric power production, (5) warming waters of the Great Lakes which could cause fish species to shift northward, (6) cool temperate, moderate temperate and grassland regions could expand northwards as the boreal forest retreats, (7) longer crop growing seasons, (8) decreased snow loads, and (9) reduced ice on the Great Lakes which would increase the length of the shipping season. The general conclusion is that adapting to changing climate will require a knowledge of how climate changes occur and how the changes are likely to affect the environment, society and economy. Changes in other key variables such as technology, personal preferences and social values will also influence the rate of climate change and Ontario`s ability to adapt to it. refs., tabs., figs.

Reappraisal of the seismotectonics of southern Ontario

International Nuclear Information System (INIS)

Mohajer, A.A.

1987-11-01

The fundamental objectives of this study were to review and improve the seismological data base as an aid in more realistic evaluation of seismic hazard in southern Ontario. For this purpose, the following procedures have been undertaken: In the first stage, the types of errors in earthquake location files are identified, sources of uncertainties are discussed and a sensitivity analysis of the errors to different parameters is presented. In the second stage, a group location technique, Joint Hypocenter Determination (JHD), has been utilized to improve the locations of a group of 67 well-recorded events, mostly from the more active region near the Ottawa River and in western Quebec. The third stage, to relocate smaller and less reliably detected events in southern Ontario, utilized a nw algorithm, 'HYPOCENTER', which proved very efficient and flexible in the test runs for handling local explosion and natural events. A preliminary interpretation of the seismicity patterns in the study regions shows that earthquakes of magnitude 3 and larger tend to align along preferred seismic trends which may, in turn, be controlled by weakness planes in the Earth's crust. These inferred trends coincide with dominant northwesterly and northeasterly striking structural directions. For earthquakes smaller than magnitude 4 prior to 1970 and for microearthquakes (M<3) which occurred near the Lake Ontario shoreline, the detection coverage was not sufficient to conclusively discuss accurate locations and causative mechanisms

Multidisciplinary characterisation of sedimentary processes in a recent maar lake (Lake Pavin, French Massif Central and implication for natural hazards

Directory of Open Access Journals (Sweden)

E. Chapron

2010-09-01

Full Text Available Sedimentation processes occurring in the most recent maar lake of the French Massif Central (Lake Pavin are documented for the first time based on high resolution seismic reflection and multibeam bathymetric surveys and by piston coring and radiocarbon dating on a sediment depocentre developed on a narrow sub aquatic plateau. This new data set confirms the mid Holocene age of maar lake Pavin formation at 6970±60 yrs cal BP and highlights a wide range of gravity reworking phenomena affecting the basin. In particular, a slump deposit dated between AD 580–640 remoulded both mid-Holocene lacustrine sediments, terrestrial plant debris and some volcanic material from the northern crater inner walls. Between AD 1200 and AD 1300, a large slide scar mapped at 50 m depth also affected the southern edge of the sub aquatic plateau, suggesting that these gas-rich biogenic sediments (laminated diatomite are poorly stable. Although several triggering mechanisms can be proposed for these prehistoric sub-aquatic mass wasting deposits in Lake Pavin, we argue that such large remobilisation of gas-rich sediments may affect the gas stability in deep waters of meromictic maar lakes. This study highlights the need to further document mass wasting processes in maar lakes and their impacts on the generation of waves, favouring the development of dangerous (and potentially deadly limnic eruptions.

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 μmol_c 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

A centrally generated primary care physician audit report does not improve colonoscopy uptake after a positive result on a fecal occult blood test in Ontario's ColonCancerCheck program.

Science.gov (United States)

Stock, D; Rabeneck, L; Baxter, N N; Paszat, L F; Sutradhar, R; Yun, L; Tinmouth, J

2017-02-01

Timely follow-up of fecal occult blood screening with colonoscopy is essential for achieving colorectal cancer mortality reduction. In the present study, we evaluated the effectiveness of centrally generated, physician-targeted audit and feedback to improve colonoscopy uptake after a positive fecal occult blood test (fobt) result within Ontario's population-wide ColonCancerCheck Program. This prospective cohort study used data sets from Ontario's ColonCancerCheck Program (2008-2011) that were linked to provincial administrative health databases. Cox proportional hazards regression was used to estimate the effect of centralized, physician-targeted audit and feedback on colonoscopy uptake in an Ontario-wide fobt-positive cohort. A mailed physician audit and feedback report identifying individuals outstanding for colonoscopy for 3 or more months after a positive fobt result did not increase the likelihood of colonoscopy uptake (hazard ratio: 0.95; 95% confidence interval: 0.79 to 1.13). Duration of positive fobt status was strongly inversely associated with the hazard of follow-up colonoscopy ( p for linear trend: audit and feedback reports does not improve colonoscopy uptake for screening participants with a positive fobt result outstanding for 3 or more months. Mailed physician-targeted screening audit and feedback reports alone are unlikely to improve compliance with follow-up colonoscopy in Ontario. Other interventions such as physician audits or automatic referrals, demonstrated to be effective in other jurisdictions, might be warranted.

Hydrogeology and ground-water quality of glacial-drift aquifers, Leech Lake Indian Reservation, north-central Minnesota

Science.gov (United States)

Lindgren, R.J.

1996-01-01

Among the duties of the water managers of the Leech Lake Indian Reservation in north-central Minnesota are the development and protection of the water resources of the Reservation. The U.S. Geological Survey, in cooperation with the Leech Lake Indian Reservation Business Committee, conducted a three and one half-year study (1988-91) of the ground-water resources of the Leech Lake Indian Reservation. The objectives of this study were to describe the availability and quality of ground water contained in glacial-drift aquifers underlying the Reservation.

The trophic role of microbial loop in an Amazonia central floodplain lake

International Nuclear Information System (INIS)

Caraballo, Pedro; Forsberg, Bruce R; Leite, Rosseval G

2012-01-01

In order to evaluate the role of heterotrophic bacteria on carbon flow in food chains of an Amazonian floodplain lake, monthly collections of these organisms were made during the hydrological year from December 2007 to November 2008. Littoral, pelagic, and aquatic macrophyte regions of the Catalao Lake in central Amazonia were sampled and bacteria were multiplied in vitro, using dissolved organic carbon (COD) of each one of the regions studied as a substrate. The bacterial biomass obtained was used for stable isotope analyses of carbon and nitrogen. These data were confronted with COD values of the four hydrological periods of the lake (dry, rising, flood and fall). In general, it was found that the main source of carbon for heterotrophic bacteria was that of C4 origin, which presented a minimum contribution of 75% of bacterial biomass, to the extent that the bacteria D13C average value -17.72 Per Mille ± 2.25 was comparing this value with the D13C of zooplankton in the same period (-33.04 Per Mille ± 3.81) permit concludes that the contribution of heterotrophic bacteria in the carbon flow to higher trophic levels in the Catalao lake is minimal.

Mattagami River Lake sturgeon entrainment : Little Long generating station facilities

International Nuclear Information System (INIS)

Seyler, J.; Evers, J.; McKinley, S.; Evans, R.R.; Prevost, G.; Carson, R.; Phoenix, D.

1996-01-01

This project and publication is the result of a collaborative effort by other Large River Ecosystem Unit of Northeast Science (NEST), Ontario Hydro in Kapuskasing, and the New Post First Nation in Cochrane, Ontario, designed to investigate potential solutions to minimize or eliminate the problem of trapped lake sturgeon in the Adam Creek Diversion. The Adam Creek Dam is used to divert excess water from the Mattagami River hydroelectric complex which consists of the Little Long, Smoky Falls, Harmon and Kipling generating stations. The lake sturgeon entrainment problem in the area was discovered in 1990. Potential solutions to the problem include the redirection of flows to mainstream, the placement of a rope barrier, electrical deterrents, physical/electrical guidance systems, sound deterrents, gate modifications, and the continued relocation of fish. The advantages and disadvantages of each of these potential solutions are discussed. Results of the analysis indicated that perceptual and physical barriers have the greatest potential to minimize lake sturgeon entrainment in Adam Creek. 25 refs., 2 tabs., 3 figs., 6 appendices

Results of forest insect and disease surveys in the central region of Ontario, 1994. Information report No. O-X-448. Annual publication

Energy Technology Data Exchange (ETDEWEB)

Evans, H.J.

1995-12-31

Report summarizing forest damage by insects, diseases and abiotic conditions in the Central Region of Ontario. Textual descriptions of pests are accompanied by maps and statistical tables. Pest conditions covered include pine false webworm, budworms, shoot borers, leafcutters, armillaria root rot and other diseases and insects. Abiotic damage reported on covers forest decline, frost injury, salt and wind damage, and winter drying. Forest health reports and special surveys are also described.

Volume reduction/solidification of liquid radioactive waste using bitumen at Ontario Hydro's Bruce Nuclear Generating Station 'A'

International Nuclear Information System (INIS)

Day, J.E.; Baker, R.L.

1995-01-01

Ontario Hydro at the Bruce Nuclear Generating Station 'A' has undertaken a program to render the station's liquid radioactive waste suitable for discharge to Lake Huron by removing sufficient radiological and chemical contaminants to satisfy regulatory requirements for emissions. The system will remove radionuclide and chemical contaminants from five different plant waste streams. The contaminants will be immobilized and stored at on-site radioactive waste storage facilities and the purified streams will be discharged. The discharge targets established by Ontario Hydro are set well below the limits established by the Ontario Ministry of Environment (MOE) and are based on the Best Available Technology Economically Achievable Approach (B.A.T.E.A.). ADTECHS Corporation has been selected by Ontario Hydro to provide volume reduction/solidification technology for one of the five waste streams. The system will dry and immobilize the contaminants from a liquid waste stream in emulsified asphalt using thin film evaporation technology

Use of the emergency room in Elliot Lake, a rural community of Northern Ontario, Canada.

Science.gov (United States)

Harris, L; Bombin, M; Chi, F; DeBortoli, T; Long, J

2004-01-01

There is ample documentation that use of hospital emergency facilities for reasons other than urgencies/emergencies results in clogged services in many urban centers. However, little has been published about similar misuse of emergency rooms/departments in rural and remote areas, where the situation is usually compounded by a scarcity of healthcare professionals. In Canada there is a shortage of physicians in rural and remote areas as a consequence of misdistribution (most physicians staying in southern urban centers after residence), and there is a chronic misuse of facilities meant for urgencies/emergencies to cope with primary healthcare needs. We address the problem in Elliot Lake, a rural Northern Ontario community of 12,000 people. The economy of Elliot Lake was based on uranium mining until the mid-1990s, when it drastically changed to become a center for affordable retirement and recreational tourism. As a consequence, at the present time the proportion of seniors in Elliot Lake doubles the Canadian average. Our objectives are to elucidate the demographics of emergency room (ER) clients and the effect of the elderly population; the nature of ER use; the perceived level of urgency of clients versus health professionals; and possible alternatives offered to non-urgent/emergency visits. This is the first study of the kind in Northern Ontario, a region the size of France. The study, conducted in July 2001, used a prospective survey, completed by patients and attending clinicians at the time of a patient's presentation to the ER of St Joseph's General Hospital. This hospital is staffed by family physicians, a nurse practitioner, and registered nurses (RNs). The catchment area population (town plus surrounding areas) of the hospital is approximately 18,000 people. ER clients were interviewed verbally, and the attending health professionals responded to written questionnaires. Demographics were recorded (age, sex, employment and marital status), as was each client

Ice formation in subglacial Lake Vostok, Central Antarctica

Science.gov (United States)

Souchez, R.; Petit, J. R.; Tison, J.-L.; Jouzel, J.; Verbeke, V.

2000-09-01

The investigation of chemical and isotopic properties in the lake ice from the Vostok ice core gives clues to the mechanisms involved in ice formation within the lake. A small lake water salinity can be reasonably deduced from the chemical data. Possible implications for the water circulation of Lake Vostok are developed. The characteristics of the isotopic composition of the lake ice indicate that ice formation in Lake Vostok occurred by frazil ice crystal generation due to supercooling as a consequence of rising waters and a possible contrast in water salinity. Subsequent consolidation of the developed loose ice crystals results in the accretion of ice to the ceiling of the lake.

Phytoplankton community responses to acidification of Lake 223, Experimental Lakes Area, Northwestern Ontario

Energy Technology Data Exchange (ETDEWEB)

Findlay, D.L.; Kasian, S.E.

1986-10-01

From 1976 to 1983 the pH of Lake 223 was artificially lowered by additions of H/sub 2/SO/sub 4/. From an initial level of 6.7, the pH was lowered at a rate of 0.5 pH units a year until it reached 5.0 and was held there for 3 yr. The decrease in pH caused major changes in the epilimnetic phytoplankton community in this lake. Biomass increased as pH decreased. Chlorophyte (Chlorella) abundance increased as pH decreased from 6.1 to 5.6 while Cyanophytes (Merismopedia and Chroococcus) and dinoflagellates (Gymnodinium and Peridinium) dominated once pH decreased below 5.6. Community diversities decreased because of these species shifts and a decrease in the number of species. The amount of edible biomass increased as the pH decreased from 6.7 to 5.6, then declined as pH decreased to 5.0. 25 refs.

Clinical Telemedicine Utilization in Ontario over the Ontario Telemedicine Network.

Science.gov (United States)

O'Gorman, Laurel D; Hogenbirk, John C; Warry, Wayne

2016-06-01

Northern Ontario is a region in Canada with approximately 775,000 people in communities scattered across 803,000 km(2). The Ontario Telemedicine Network (OTN) facilitates access to medical care in areas that are often underserved. We assessed how OTN utilization differed throughout the province. We used OTN medical service utilization data collected through the Ontario Health Insurance Plan and provided by the Ministry of Health and Long Term Care. Using census subdivisions grouped by Northern and Southern Ontario as well as urban and rural areas, we calculated utilization rates per fiscal year and total from 2008/2009 to 2013/2014. We also used billing codes to calculate utilization by therapeutic area of care. There were 652,337 OTN patient visits in Ontario from 2008/2009 to 2013/2014. Median annual utilization rates per 1,000 people were higher in northern areas (rural, 52.0; urban, 32.1) than in southern areas (rural, 6.1; urban, 3.1). The majority of usage in Ontario was in mental health and addictions (61.8%). Utilization in other areas of care such as surgery, oncology, and internal medicine was highest in the rural north, whereas primary care use was highest in the urban south. Utilization was higher and therapeutic areas of care were more diverse in rural Northern Ontario than in other parts of the province. Utilization was also higher in urban Northern Ontario than in Southern Ontario. This suggests that telemedicine is being used to improve access to medical care services, especially in sparsely populated regions of the province.

Best management practices guide for waterpower projects: lake sturgeon

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-06-15

There are challenges and potential risks inherent in waterpower generation activities and this guide focuses on the fish species of lake sturgeon in Ontario and provides a synthesis of industry-wide knowledge and best available science indicators regarding hydropower impacts. This manual is written as guidance to proponents and practitioners but also to owners and operators, and provides them with tools and approaches to implement management strategies that will minimize potential impacts of waterpower generation installations on lake sturgeon and its habitat.

Volume reduction/solidification of liquid radioactive waste using bitumen at Ontario hydro's Bruce nuclear generating station open-quotes Aclose quotes

International Nuclear Information System (INIS)

Day, J.E.; Baker, R.L.

1994-01-01

Ontario Hydro at the Bruce Nuclear Generating Station open-quotes Aclose quotes has undertaken a program to render the station's liquid radioactive waste suitable for discharge to Lake Huron by removing sufficient radiological and chemical contaminants from five different plant waste streams. The contaminants will be immobilized and stored at on-site radioactive waste storage facilities and the purified streams will be discharged. The discharge targets established by Ontario Hydro are set well below the limits established by the Ontario Ministry of Environment (MOE) and are based on the Best Available Technology Economically Achievable Approach (B.A.T.E.A.). ADTECHS Corporation has been selected by Ontario Hydro to provide volume reduction/solidification technology for one of the five waste streams. The system will dry and immobilize the contaminants from a liquid waste stream in emulsified asphalt using thin film evaporation technology

Adequacy of the ophthalmology workforce under Ontario's Local Health Integration Networks.

Science.gov (United States)

Lin, Tony; Xu, Mark; Hooper, Philip L

2016-06-01

To determine the current distribution of ophthalmologists across Ontario's Local Health Integration Networks (LHINs) and the influence on LHIN-specific cataract surgery wait times. Cross-sectional study. Ophthalmologists listed in the College of Physicians and Surgeons (CPSO) database and the Canadian population. A list of ophthalmologists and their practice locations were obtained from the CPSO website. The total population count for Ontario was obtained from the Statistics Canada census. The population counts for the population aged 65 years and older were generated using the Canadian Socioeconomic Information Management System (CANSIM) table 109-5425. Cataract surgery wait times were obtained from the Ontario Ministry of Health. Statistical analysis was completed using Microsoft Excel using StatPlus software. There are currently 3.28 ophthalmologists per 100 000 total population in Ontario. LHIN-specific ratios ranged from 8.87 (Toronto Central) to 1.67 (Central West), with 3 out of 14 LHINs having met the previously recommended ratio of 3.37. Median cataract surgery wait times ranged from 30 to 72 days. Although the number of cataract surgeries performed was positively correlated with the population aged 65 years and older (p < 0.001), there was no statistically significant association between wait times and number of cataract cases per 1000 population (p = 0.41). Although Ontario appears to have a sufficient number of ophthalmologists overall, there is significant variation in the distribution of the ophthalmology workforce at the LHIN level. This variation did not appear to significantly influence LHIN-specific cataract surgery wait times. Copyright © 2016 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

Mining, metallurgy and the historical origin of mercury pollution in lakes and watercourses in Central Sweden.

Science.gov (United States)

Bindler, Richard; Yu, Ruilian; Hansson, Sophia; Classen, Neele; Karlsson, Jon

2012-08-07

In Central Sweden an estimated 80% of the lakes contain fish exceeding health guidelines for mercury. This area overlaps extensively with the Bergslagen ore region, where intensive mining of iron ores and massive sulfide ores occurred over the past millennium. Although only a few mines still operate today, thousands of mineral occurrences and mining sites are documented in the region. Here, we present data on long-term mercury pollution in 16 sediment records from 15 lakes, which indicate that direct release of mercury to lakes and watercourses was already significant prior to industrialization (mines. Although the timing and magnitude of the historical increases in mercury are heterogeneous among lakes, the data provide unambiguous evidence for an incidental release of mercury along with other mining metals to lakes and watercourses, which suggests that the present-day problem of elevated mercury concentrations in the Bergslagen region can trace its roots back to historical mining.

Crotch Lake dam rehabilitation project

International Nuclear Information System (INIS)

Brunet, G.; Dobrowolski, E.

1999-01-01

Replacement of the existing wood crib dam structure on Crotch Lake on the Mississippi River in eastern Ontario that provided water storage for the power production at High Falls Generating Station, became necessary when it was determined that the dam did not meet Ontario-Hydro's safety standards. This paper describes the project of replacing the existing structure with a PVC coated gabion wall with waterproofing. The entire structure was covered with three layers of wire mesh, laced together, and criss-crossed for superior strength and rigidity. The work was completed in 28 days with no environmental impact . Life expectancy of the new structure is in excess of 40 years. With periodic maintenance of the gabion mat cover, life span could be extended an additional 20 to 40 years. 5 figs

Geochemistry of aquatic and terrestrial sediments, Precambrian shield of southeastern Ontario

Energy Technology Data Exchange (ETDEWEB)

Hornbrook, E H.W.; Kettles, I M; Shilts, W W

1986-12-01

Lake water and sediment samples from approximately 2200 lakes and glacial sediment (sub-solum) samples from about 1800 sites were collected throughout a 38,000 km/sup 2/ rectangular area extending from Georgian Bay east to the Ottawa and St. Lawrence Rivers, Ontario, Canada. Lake water alkalinity and pH patterns are similar to the distribution of carbonate components in glacial drift. Carbonate-rich drift derived from the Paleozoic limestone terrain on the northeast flank of the Precambrian Frontenac Arch has been dispersed in a south-westward direction across a variety of non-calcareous metasedimentary and igneous rocks of the Canadian Shield, providing a buffering capacity to lakes situated in granitic terrain. The distribution patterns of mobile trace and minor elements are influenced by geochemical processes associated with subaerial weathering, ground and surface water transport, and the geochemical environment within the lakes themselves. Although composition of the drift is generally reflected by lake geochemistry, these post depositional processes can cause significant variations between patterns derived from the two sample types. Anions and cations such as SO/sub 4//sup 2 -/, Cl/sup -/, Na/sup +/, and F/sup -/ exhibit concentration patterns thought to reflect both anthropogenic inputs and natural variations due to differences in the geology. All regional geochemical patterns may show evidence of local enhancement caused by high concentrations of chemically distinctive minerals in drift or nearby bedrock. 4 references.

Environmental review of natural gas production in Lake Erie

International Nuclear Information System (INIS)

O'Shea, K.

2002-01-01

The water of Lake Erie is used as a source of drinking water for Ontario, New York, Pennsylvania, Ohio and Michigan. An environmental review has been conducted to determine the impact of drilling operations on the overall ecology of the lake. Since 1913, 2000 natural gas wells have been drilled in Lake Erie, of which 550 currently produce gas and account for 75 per cent of Ontario's total gas production. 180 wells are shut-in or suspended and the remaining wells have been abandoned. The gas wells are connected to onshore production facilities by approximately 1,600 km of small diameter pipelines that lie buried near shore or on top of the lake bed. Nearly 90 per cent of the in-lake infrastructure is in water depths of more than 20 metres. Talisman Energy is actively involved with the Canadian Coast Guard, the Department of Fisheries and Oceans, and the Ministry of Natural Resources to ensure cooperation between regulators and off-shore personnel. The environmental assessment of natural gas production in Lake Erie included a review of regulatory and best management practices, a biophysical overview of the lake, and a review of drilling practices, well completions, handling of waste streams, materials management, operations inspections, wastewater discharge, air emissions, and oil spills. It was revealed that for most drilling programs, cuttings are washed and discharged to the Lake. Ongoing testing will determine the impact that this practice has on benthic populations. The drill muds used for drilling operations are water based, environmentally friendly, and re-used between well locations. For completion programs, all well activities are closed circuit operations. Wells are abandoned through plugging with cement, removing wellheads and casing below the lake bottom. There has been a reported volume of about 23,000 litres of spilled product from 1990 to 2001, of which 68 per cent has come from 3 industrial companies that operate near Lake Erie. The offshore gas

A comparison of mercury levels in feathers and eggs of osprey (Pandion haliaetus) in the North American Great Lakes.

Science.gov (United States)

Hughes, K D; Ewins, P J; Clark, K E

1997-11-01

Osprey (Pandion haliaetus) eggs and chick feathers were collected for mercury analysis from nests at four Great Lakes study areas in Ontario (three "naturally formed" lakes in southern Ontario and one reservoir in northern Ontario) and two New Jersey study areas in 1991-1994. Adult osprey feathers were sampled from three Great Lakes study areas in 1991. Feathers sampled from chicks (approximately 28-35 days old) appear to be better indicators of local contaminant conditions since spatial patterns of mercury in known prey, yellow perch (Perca flavescens), also collected in these areas, were more similar to chick feathers than to eggs. Mercury levels were less variable in chick feathers than in eggs. Estimates of biomagnification factors using prey of known size at these areas were also less variable in feathers than in eggs. At naturally formed lakes, no significant correlation in mercury levels between eggs and chick feathers from the same nest was apparent, suggesting that the source of mercury contamination was not the same in these two tissues: mercury levels in eggs reflect mercury acquired on the breeding grounds, wintering grounds, and migratory route; mercury levels in chick feathers reflect local dietary conditions on the breeding grounds. Mercury levels in both osprey eggs and chick feathers were higher at the Ogoki Reservoir than at naturally formed lakes. Adult osprey feathers had higher mercury concentrations than chick feathers. Mercury levels in osprey eggs, chick feathers, and adult feathers did not approach levels associated with toxic reproductive effects.

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

International Nuclear Information System (INIS)

Covello, D.M.; Pinet, P.R.; McClennen, C.E.; Knotts, K.A.

1993-01-01

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

Seven steps to an energy efficient Ontario

International Nuclear Information System (INIS)

2003-01-01

The future of the electricity market in Ontario is examined in light of the recent debate concerning deregulation. This report focuses on measures that would have to be taken to ensure that there will be sufficient electricity available to serve the needs of Ontario. Increasing supply, or decreasing demand are discussed as the obvious answers to the problem at hand. The report concludes that: (1) mechanisms to encourage Demand Side Management and Demand Response have all but disappeared since the opening of the competitive electricity market in Ontario, (2) the current market structure does nothing to stimulate increased supply, nor does it encourage measures to reduce demand; as such, the result is an unsustainable situation. The report further concludes that Demand Side Management and Demand Response programs are essential components of the success of Ontario's evolving electricity market, and recommends programs that are designed and implemented in a manner that dovetail with parallel policies dealing with supply challenges. Seven essential elements of such a policy are discussed. These are: (1) vision and a clear set of goals for demand side management; (2) appropriate market drivers, principles and pricing incentives; (3) a central co-ordinating authority for managing demand side management; (4) appropriate implementation agents to manage programs and processes; (5) incentives to motivate change; (6) widespread education of the market; and (7) appropriate tactics to enable demand side management in sectors

Analysis of Regional GPS Networks in Eastern Ontario

Science.gov (United States)

Samadi Alinia, H.; Tiampo, K. F.

2014-12-01

Although stable, intraplate region of eastern Canada is considered low rate deformation area in the North American plate, the retreat of large ice sheets during deglaciation in the last 20 ka has resulted in horizontal and vertical deformation of the Earth's in eastern Ontario. Present-day glacial isostatic adjustment (GIA) uplift rates approach 10 mm/yr or more at Hudson Bay and decrease with distance southeastward. Current GIA models forecast that the hinge line between uplift to the northwest and subsidence to the southeast lies somewhere near the Saint Lawrence valley in eastern Canada [Tushingham and Peltier, 1991; Peltier, 2002]. Employing continuous Global Positioning System (cGPS) observations and high precision tools for processing and then analyzing each component of derived time series are important tools to monitor the associated regional crustal deformation with good accuracies. Here we describe the analysis of coordinate time series of cGPS stations scattered sparsely throughout southeastern Ontario and between Ottawa and the east coast of Hudson Bay. Here, the two most reliable local networks, each including 4 to 6 reference stations, were selected for analysis. Data for period of approximately five years, 2008-2012.9, was processed with Bernese 5.0 over several campaigns. Individual cGPS coordinate time series were generated for each station and basic parameters, such as mean, variance and repeatability, were estimated. The time series are corrected with respect to the rigid plate motion and seasonal variations and advanced time series analysis techniques, including spectral analysis and principal component analysis were implemented. Post-processing of the time series reproduces the general GIA spatial pattern. Results also show that the vertical velocities of all stations in the solution are consistent with the GIA model uplift rate and are consistent with other cGPS sites in eastern Canada and increases from north of lake of Ontario (approximately

Zebra mussels mitigation at Ontario Hydro's hydroelectric generating facilities

International Nuclear Information System (INIS)

Dorneanu, A.M.

1992-01-01

The Great Lakes and their connecting channels have recently been invaded by a tiny freshwater mollusc that has already cost Ontario Hydro millions of dollars. Dreissena polymorpha, commonly known as the zebra mussel, entered the great lakes in ballast water carried by a ship from Europe in 1985. These mussels threaten to reduce or totally block the flow of water in auxiliary systems of any generating station, water treatment plant or municipal water facility that uses raw lake water and to cause accelerated corrosion of the metallic substrate to which they attach themselves. To satisfy the immediate need for control, chlorination was identified as the most effective interim measure to prevent the biofouling of the raw water systems. Detection and monitoring of mussels and the installation, operation, environmental constraints, benefits and deficiencies of the chemical treatment system are presented. Long term objectives for control of the mussels are to develop alternatives to chlorination (ozone, hydrogen peroxide, protective coatings, thermal shock, mechanical filtration, etc.) for application at existing facilities and for incorporation into the design of new facilities and rehabilitation programs. 3 refs., 5 figs

Late Glacial and Holocene sedimentary evolution of Czechowskie Lake (Eastern Pomerania, North Central Poland)

Science.gov (United States)

Kordowski, Jarosław; Błaszkiewicz, Mirosław; Kramkowski, Mateusz; Noryśkiewicz, Agnieszka M.; Słowiński, Michał; Tyszkowski, Sebastian; Brauer, Achim; Ott, Florian

2015-04-01

Czechowskie Lake is located in north-central Poland in Tuchola Forest, about 100 kilometers SW away from Gdańsk. In the deepest parts of the lake there are preserved laminated sediments with an excellent Holocene climatic record. The lake has the area of 76,6 ha. Actual water level is at 109,9 m a.s.l. The average depth is 9,59 m, maximal 32 m. It occupies a large subglacial channel, reproduced within the glacifluvial sediments of the last glaciation. The lake has a history reaching back to Pommeranian phase which is proved by analysis of sedimentary succesions in the vicinity of present-day waterbody. Primarily it come to existence as an very variable ice dammed lake but after dead ice and permafrost desintegration it changed into a stable lake. In the terrestrialised part oft the lake and in its litoral zone there were curried out numerous boreholes within limnic and slope sediments. They have been analysed in respect to lithology and structure. Some of them were also investigated palynologically which along with radiocarbon datings allowed to reconstruct major phases of the water level fluctuations. The maximum infilling with the limnic and telmatic sediments reaches over 12 m. In the bottom of the lake there is a marked presence of many overdeepenings with the diameter of dozen or several dozen meters and the depth of up to 10 m with numerous, distinct throughs between them. They favoured the preservation of the lamination in the deepest parts of the lake due to waves hampering and stopping of the density circulation in the lake waterbody. The analysis of limnic sediments revealed considerable spatial and temporal variability mainly in dependance of the area of the water body and water level in time of deposition. In the lake are recorded three distinct phases of lake level decrease. The sedimentary evolution in the isolated minor lake basins showed gradual decrease of mineral and organic deposition in favour for carbonate one although in places separated by

Bathymetry and composition of Titan's Ontario Lacus derived from Monte Carlo-based waveform inversion of Cassini RADAR altimetry data

Science.gov (United States)

Mastrogiuseppe, M.; Hayes, A. G.; Poggiali, V.; Lunine, J. I.; Lorenz, R. D.; Seu, R.; Le Gall, A.; Notarnicola, C.; Mitchell, K. L.; Malaska, M.; Birch, S. P. D.

2018-01-01

Recently, the Cassini RADAR was used to sound hydrocarbon lakes and seas on Saturn's moon Titan. Since the initial discovery of echoes from the seabed of Ligeia Mare, the second largest liquid body on Titan, a dedicated radar processing chain has been developed to retrieve liquid depth and microwave absorptivity information from RADAR altimetry of Titan's lakes and seas. Herein, we apply this processing chain to altimetry data acquired over southern Ontario Lacus during Titan fly-by T49 in December 2008. The new signal processing chain adopts super resolution techniques and dedicated taper functions to reveal the presence of reflection from Ontario's lakebed. Unfortunately, the extracted waveforms from T49 are often distorted due to signal saturation, owing to the extraordinarily strong specular reflections from the smooth lake surface. This distortion is a function of the saturation level and can introduce artifacts, such as signal precursors, which complicate data interpretation. We use a radar altimetry simulator to retrieve information from the saturated bursts and determine the liquid depth and loss tangent of Ontario Lacus. Received waveforms are represented using a two-layer model, where Cassini raw radar data are simulated in order to reproduce the effects of receiver saturation. A Monte Carlo based approach along with a simulated waveform look-up table is used to retrieve parameters that are given as inputs to a parametric model which constrains radio absorption of Ontario Lacus and retrieves information about the dielectric properties of the liquid. We retrieve a maximum depth of 50 m along the radar transect and a best-fit specific attenuation of the liquid equal to 0.2 ± 0.09 dB m-1 that, when converted into loss tangent, gives tanδ = 7 ± 3 × 10-5. When combined with laboratory measured cryogenic liquid alkane dielectric properties and the variable solubility of nitrogen in ethane-methane mixtures, the best-fit loss tangent is consistent with a

The effectiveness and resilience of phosphorus management practices in the Lake Simcoe watershed, Ontario, Canada

Science.gov (United States)

Crossman, J.; Futter, M. N.; Palmer, M.; Whitehead, P. G.; Baulch, H. M.; Woods, D.; Jin, L.; Oni, S. K.; Dillon, P. J.

2016-09-01

Uncertainty surrounding future climate makes it difficult to have confidence that current nutrient management strategies will remain effective. This study used monitoring and modeling to assess current effectiveness (% phosphorus reduction) and resilience (defined as continued effectiveness under a changing climate) of best management practices (BMPs) within five catchments of the Lake Simcoe watershed, Ontario. The Integrated Catchment Phosphorus model (INCA-P) was used, and monitoring data were used to calibrate and validate a series of management scenarios. To assess current BMP effectiveness, models were run over a baseline period 1985-2014 with and without management scenarios. Climate simulations were run (2070-2099), and BMP resilience was calculated as the percent change in effectiveness between the baseline and future period. Results demonstrated that livestock removal from water courses was the most effective BMP, while manure storage adjustments were the least. Effectiveness varied between catchments, influenced by the dominant hydrological and nutrient transport pathways. Resilience of individual BMPs was associated with catchment sensitivity to climate change. BMPs were most resilient in catchments with high soil water storage capacity and small projected changes in frozen-water availability and in soil moisture deficits. Conversely, BMPs were less resilient in catchments with larger changes in spring melt magnitude and in overland flow proportions. Results indicated that BMPs implemented are not always those most suited to catchment flow pathways, and a more site-specific approach would enhance prospects for maintaining P reduction targets. Furthermore, BMP resilience to climate change can be predicted from catchment physical properties and present-day hydrochemical sensitivity to climate forcing.

Environmental evidence of fossil fuel pollution in Laguna Chica de San Pedro lake sediments (Central Chile)

International Nuclear Information System (INIS)

Chirinos, L.; Rose, N.L.; Urrutia, R.; Munoz, P.; Torrejon, F.; Torres, L.; Cruces, F.; Araneda, A.; Zaror, C.

2006-01-01

This paper describes lake sediment spheroidal carbonaceous particle (SCP) profiles from Laguna Chica San Pedro, located in the Biobio Region, Chile (36 o 51' S, 73 o 05' W). The earliest presence of SCPs was found at 16 cm depth, corresponding to the 1915-1937 period, at the very onset of industrial activities in the study area. No SCPs were found at lower depths. SCP concentrations in Laguna Chica San Pedro lake sediments were directly related to local industrial activities. Moreover, no SCPs were found in Galletue lake (38 o 41' S, 71 o 17.5' W), a pristine high mountain water body used here as a reference site, suggesting that contribution from long distance atmospheric transport could be neglected, unlike published data from remote Northern Hemisphere lakes. These results are the first SCP sediment profiles from Chile, showing a direct relationship with fossil fuel consumption in the region. Cores were dated using the 21 Pb technique. - The lake sediment record of SCPs shows the record of fossil-fuel derived pollution in Central Chile

Environmental evidence of fossil fuel pollution in Laguna Chica de San Pedro lake sediments (Central Chile)

Energy Technology Data Exchange (ETDEWEB)

Chirinos, L. [Centro de Ciencias Ambientales EULA-Chile, Universidad de Concepcion, PO Box 160-C, Concepcion (Chile)]. E-mail: lchirin@pucp.edu.pe; Rose, N.L. [Environmental Change Research Centre, University College London, 26 Bedford Way, London WG1HOAP (United Kingdom); Urrutia, R. [Centro de Ciencias Ambientales EULA-Chile, Universidad de Concepcion, PO Box 160-C, Concepcion (Chile); Munoz, P. [Departamento de Biologia Marina, Universidad Catolica del Norte, Larrondo 1281, Coquimbo (Chile); Torrejon, F. [Centro de Ciencias Ambientales EULA-Chile, Universidad de Concepcion, PO Box 160-C, Concepcion (Chile); Torres, L. [Departamento de Botanica, Universidad de Concepcion, Concepcion (Chile); Cruces, F. [Departamento de Botanica, Universidad de Concepcion, Concepcion (Chile); Araneda, A. [Centro de Ciencias Ambientales EULA-Chile, Universidad de Concepcion, PO Box 160-C, Concepcion (Chile); Zaror, C. [Facultad de Ingenieria Quimica, Universidad de Concepcion, Concepcion (Chile)

2006-05-15

This paper describes lake sediment spheroidal carbonaceous particle (SCP) profiles from Laguna Chica San Pedro, located in the Biobio Region, Chile (36{sup o} 51' S, 73{sup o} 05' W). The earliest presence of SCPs was found at 16 cm depth, corresponding to the 1915-1937 period, at the very onset of industrial activities in the study area. No SCPs were found at lower depths. SCP concentrations in Laguna Chica San Pedro lake sediments were directly related to local industrial activities. Moreover, no SCPs were found in Galletue lake (38{sup o} 41' S, 71{sup o} 17.5' W), a pristine high mountain water body used here as a reference site, suggesting that contribution from long distance atmospheric transport could be neglected, unlike published data from remote Northern Hemisphere lakes. These results are the first SCP sediment profiles from Chile, showing a direct relationship with fossil fuel consumption in the region. Cores were dated using the {sup 21}Pb technique. - The lake sediment record of SCPs shows the record of fossil-fuel derived pollution in Central Chile.

Lake-level fluctuations since the Last Glaciation in Selin Co (lake), Central Tibet, investigated using optically stimulated luminescence dating of beach ridges

International Nuclear Information System (INIS)

Li Dewen; Li Yingkui; Ma Baoqi; Zhao, Junxiang; Dong Guocheng; Wang Liqiang

2009-01-01

This paper presents a preliminary study on lake-level fluctuations since the Last Glaciation in Selin Co (lake), Central Tibet, by dating four groups of beach ridges using optically stimulated luminescence (OSL). The highest/oldest beach ridge group (>100 m higher than the current lake level) is dated back to 67.9 ± 2.4 ka BP, corresponding to the early stage of the Last Glaciation (marine isotope stage (MIS) 4). This date further supports that no plateau-scale ice sheet covered the Tibetan Plateau during the Last Glaciation. The other three groups produce OSL ages of 30.4 ± 2.9 to 18.6 ± 1.7, 12.5 ± 1.6 to 9.2 ± 0.5, and 6.9 ± 0.2 ka BP respectively, most likely corresponding to cold or wet climate periods of the late stage of the Last Glaciation (MIS 2), deglaciation, and Holocene Hypsithermal. On the plateau scale, these four beach ridge groups are almost synchronous with advances or standstills of Himalayan glaciers, indicating similar climate controls across the central and southern Tibetan Plateau, and being consistent with the conclusion, obtained from nearby ice core records, that this area is affected by the South Asia monsoon. Furthermore, beach ridges are also synchronous with fluvial terraces in the northern Tibetan Plateau, implying common driving forces during their formation. Therefore, some terraces may be formed as a result of climate events rather than being of tectonic origin.

Morphometric variation among spawning cisco aggregations in the Laurentian Great Lakes: are historic forms still present?

Science.gov (United States)

Yule, Daniel L.; Moore, Seth A.; Ebener, Mark P.; Claramunt, Randall M.; Pratt, Thomas C.; Salawater, Lorrie L.; Connerton, Michael J.

2013-01-01

Cisco (Coregonus artedi Leseur, formerly lake herring Leucichthys artedi Leseur) populations in each of the Laurentian Great Lakes collapsed between the late 1920s and early 1960s following a multitude of stressors, and never recovered in Lakes Michigan, Erie and Ontario. Prior to their collapse, Koelz (1929) studied Leucichthys spp. in the Great Lakes basin and provided a description of their diversity. Three cisco morphotypes were described; a ‘slim terete’morphotype (L. artedi artedi), a ‘deep compressed’ morphotype (L. artedi albus), and a deep-bodied form resembling tullibee in western Canadian lakes (L. artedi manitoulinus). Based on body measurements of 159 individuals (Koelz 1929), we used discriminant function analysis (DFA) to discriminate historic morphotypes. Shapes of historic morphotypes were found to vary significantly (Pillai’s trace = 1.16, P cisco. Important discriminating measurements included body depth, eye diameter, and dorsal fin base and height. Between October-November of 2007-2011, we sampled cisco from 16 Great Lakes sites collecting digital photographs of over 1, 700 individuals. We applied the DFA model to their body measurements and classified each individual to a morphotype. Contemporary cisco from Lakes Superior, Ontario and Michigan were predominantly classified as artedi, while the most common classifications from northern Lake Huron were albus and manitoulinus. Finding historic morphotypes is encouraging because it suggests that the morphological variation present prior to their collapse still exists. We conclude that contemporary cisco having shapes matching the missing historic morphotypes in the lower lakes warrant special consideration as potential donor populations in reestablishment efforts.

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

Science.gov (United States)

Gorman, Owen T.; Weidel, Brian C.

2014-01-01

Lake Michigan. In general, trends in year-class strengths were less concordant across the basin and only coregonids showed statistical agreement across the upper Great Lakes. The appearance of strong and moderate year-classes of Bloater in Lake Huron in 2005- 2011 countered the trend of continuing weak year-classes of coregonids in Lakes Michigan and Superior. Not shown in our analysis is the appearance of the 2013 year-class of Bloater in Huron, the largest to date. There was no agreement in cross-basin trends in year-class strengths for Rainbow Smelt and Alewife, although there was agreement between pairs of lakes. Although there was statistical agreement in trends of age-0 and older Round Goby biomass among lakes where this species has successfully invaded (Michigan, Huron, Erie and Ontario), temporal patterns of biomass in each lake were different. Round Goby may be approaching equilibrium in Lake Erie, peaking in Lake Huron, and expanding in Lake Michigan. The trend in Lake Ontario remains unclear. Declining abundance in Lake Erie has corresponded with evidence that Round Goby have become increasingly incorporated into piscivore diets, e.g., Lake Trout, Walleye, Smallmouth Bass, Yellow Perch, and Burbot in Lakes Michigan, Huron, Erie, and Ontario. Round Goby continue to be absent from spring bottom trawl assessments in Lake Superior, but their presence in the harbors and embayments of Duluth and Thunder Bay (U.S. Geological Survey and Ontario Ministry of Natural Resources, unpublished data), suggests that there is potential for future colonization.

Implications of climatic change for tourism and recreation in Ontario

International Nuclear Information System (INIS)

Wall, G.; Harrison, R.; Kinnaird, V.; McBoyle, G.; Quinland, C.

1988-01-01

Scenarios for climatic change associated with a doubling of atmospheric carbon dioxide were employed in an assessment of the impacts of climate change on tourism and recreation in Ontario. A warmer climate resulting from such change may mean declining lake levels with associated changes in the ecological interest and recreational potential of wetlands, as shown by case studies on two parks near Great Lakes shorelines. In the skiing industry, the length of ski seasons will be reduced in the northern part of the province, but the key holiday periods (when a large portion of total business is conducted) should still fall within the reliable ski season. Further south, the ski season in the South Georgian Bay region could be eliminated. Summer recreational activities are likely to have extended seasons, and the viability of summer recreational enterprises may increase, with associated positive benefits to neighboring communities. 2 refs., 6 figs., 3 tabs

Report of the advisory group on demand-side management and demand response in Ontario in response to the Minister's directive to the Ontario Energy Board

International Nuclear Information System (INIS)

2003-01-01

The Ontario Energy Board was directed in June 2003 to consult with stakeholders to identify and review options for the delivery of demand-side management (DSM) and demand response (DR) activities within the electricity sector, including the role of local distribution companies (distributors) in such activities. A total of 118 stakeholders participated in the consultation process, and 31 representatives from all sectors were then invited to take part in an advisory working group to develop options to be considered by the Board when preparing the recommendations to the Minister. This report presents a consolidation of the Group's working documents and the results of deliberations both as a unit and in small groups. The best way to present the many newly developed models was as a single Central Agency model demonstrating variations in the role of the Central Agency and other players in the electricity market. The paper was divided into the following six sections: introduction; market issues; demand response framework option; central agency framework-alternative models; Ontario Energy Board-wires companies DSM framework; and, general issues

Assessing the financial positions of Ontario`s new electricity companies

Energy Technology Data Exchange (ETDEWEB)

Connell, T. [Standard and Poor`s, Toronto, ON (Canada)

1999-11-01

This paper describes the methodology, including the criteria factors, comparable ratings and key credit issues used in assessing the financial positions of Ontario Power Generation Inc., and the Ontario Hydro Services Company. The rating criteria factors include both business factors (such as ownership structure, regulation, service area, operations, management, etc.,) and financial factors (e.g. financial policies and guidelines, recent financial performance, margin analysis, capital structure and borrowing plans, financial projections and sensitivities). Key credit issues include considerations of competitive dynamics, nuclear portfolio performance (for Genco), regulatory changes, cost control, capital spending program, retail business exposure, future financial performance. Comparisons are made with corresponding positions of comparable entities in Australia, Finland, New Zealand, the UK, and the USA. In the case of Ontario Power Generation Inc., the company is assessed to have significant advantages initially, but various uncertainties over the medium term warrant a more cautious view of the credit profile. For the Ontario Hydro Services Company the business risks appear to be low and moderate leverage entails a strong, stable credit profile. The overall assessment of the two companies is that while certain questions such as the workability and credibility of the new industry structure, the problem of stranded debt and questions about the liquidity of market participants remain unsolved, Ontario Power Generation Inc., and the Ontario Hydro Services Company ratings compare favorably with ratings of global industry peers.

Ontario energy review

International Nuclear Information System (INIS)

1990-03-01

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.)

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

Science.gov (United States)

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

1996-01-01

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

Spatial and Temporal Trends of Snowfall in Central New York - A Lake Effect Dominated Region

Science.gov (United States)

Hartnett, Justin Joseph

Central New York is located in one of the snowiest regions in the United States, with the city of Syracuse, New York the snowiest metropolis in the nation. Snowfall in the region generally begins in mid-November and lasts until late-March. Snow accumulation occurs from a multitude of conditions: frontal systems, mid-latitude cyclones, Nor'easters, and most notably lake-effect storms. Lake effect snowfall (LES) is a difficult parameter to forecast due to the isolated and highly variable nature of the storm. Consequently, studies have attempted to determine changes in snowfall for lake-effect dominated regions. Annual snowfall patterns are of particular concern as seasonal snowfall totals are vital for water resources, winter businesses, agriculture, government and state agencies, and much more. Through the use of snowfall, temperature, precipitation, and location data from the National Weather Service's Cooperative Observer Program (COOP), spatial and temporal changes in snowfall for Central New York were determined. In order to determine climatic changes in snowfall, statistical analyses were performed (i.e. least squares estimation, correlations, principal component analyses, etc.) and spatial maps analyzed. Once snowfall trends were determined, factors influencing the trends were examined. Long-term snowfall trends for CNY were positive for original stations (˜0.46 +/- 0.20 in. yr -1) and homogenously filtered stations (0.23 +/- 0.20 in. yr -1). However, snowfall trends for shorter time-increments within the long-term period were not consistent, as positive, negative, and neutral trends were calculated. Regional differences in snowfall trends were observed for CNY as typical lake-effect areas (northern counties, the Tug Hill Plateau and the Southern Hills) experienced larger snowfall trends than areas less dominated by LES. Typical lake-effect months (December - February) experienced the greatest snowfall trend in CNY compared to other winter months. The

Ontario Hydro's nuclear program

International Nuclear Information System (INIS)

McCredie, J.

1984-01-01

This report briefly describes Ontario Hydro's nuclear program, examining the design and construction status, and the future from Ontario Hydro's perspective. Ontario Hydro relies heavily on nuclear power. Nuclear fuel was responsible for approximately 34% of Ontario Hydro's energy production in 1983. The nuclear proportion was supplied by twelve operating units located: NPD, Douglas Point, Pickering A and B. It is expected that by approximately 1992, 65% of the total energy needs will be generated through nuclear power

Omitted Costs, Inflated Benefits: Renewable Energy Policy in Ontario

Science.gov (United States)

Gallant, Parker; Fox, Glenn

2011-01-01

The government of Ontario has adopted wind energy development as an alternative energy source. It enacted the Green Energy and Economy Act, May 2009, with the intention to fast track the approval process regarding industrial wind turbines. The Act legislated a centralized decision making process while removing local jurisdictional authority.…

Acidity of Lakes and Impoundments in North-Central Minnesota

Science.gov (United States)

Elon S. Verry

1981-01-01

Measurements of lake and impoundment pH for several years, intensive sampling within years, and pH-calcium plots verify normal pH levels and do not show evidence of changes due to acid precipitation. These data in comparison with general lake data narrow the northern Lake States area in which rain or snow may cause lake acidification.

Ra-226 concentrations in blueberries Vaccinium angustifolium Ait. near an inactive uranium tailings site in Elliot Lake, Ontario, Canada

International Nuclear Information System (INIS)

Dave, N.K.; Lim, T.P.; Cloutier, N.R.

1985-01-01

Ra-226 concentrations were measured in blueberries growing around the Stanrock uranium tailings area near Elliot Lake, Ontario, Canada. Elevated levels of total Ra-226 ranging between 20 to 290 mBq g -1 were observed in samples collected within 500 m from the tailings. Highest levels, approx. 285 mBq g -1 , were observed in a sample collected on a tailings spill. For sites located more than 500 m away in the upwind direction, and those situated at distances greater than 1 km downwind from the waste pile, the total Ra-226 concentrations approached background levels which were measured as 2 to 6 mBq g -1 . Approximately 17% of the total Ra-226 measured was removable by washing the samples with distilled water. Wind dispersal of the tailings material and its deposition in the form of dust on blueberries was believed to be responsible for the external contamination. Based on the ICRP recommended dose limits for oral intake of Ra-226, it was calculated that approximately 160 kg a -1 , 3350 kg a -1 and 47 kg a -1 of washed blueberries from inside and outside the influenced zone, and from the tailings spill site, respectively, would need to be consumed before the individual annual limit for the general public was exceeded. (author)

Ichthyoplankton assemblages of coastal west-central Lake Erie and associated habitat characteristics

Science.gov (United States)

McKenna, J.E.; Hunter, R. Douglas; Fabrizio, M.C.; Savino, J.F.; Todd, T.N.; Bur, M.

2008-01-01

Early life stage survival often determines fish cohort strength and that survival is affected by habitat conditions. The structure and dynamics of ichthyoplankton assemblages can tell us much about biodiversity and fish population dynamics, but are poorly understood in nearshore areas of the Great Lakes, where most spawning and nursery habitats exist. Ichthyoplankton samples were collected with a neuston net in waters 2-13 m deep weekly or biweekly from mid-April through August, during 3 years (2000-2002) as part of a study of fish assemblages in west-central Lake Erie. A suite of abiotic variables was simultaneously measured to characterize habitat. Cluster and ordination analyses revealed several distinct ichthyoplankton assemblages that changed seasonally. A lake whitefish (Coregonus clupeaformis) dominated assemblage appeared first in April. In May, assemblages were dominated by several percid species. Summer assemblages were overwhelmingly dominated by emerald shiner (Notropis atherinoides), with large gizzard shad (Dorosoma cepedianum) and alewife (Alosa pseudoharengus) components. This seasonal trend in species assemblages was also associated with increasing temperature and water clarity. Water depth and drift processes may also play a role in structuring these assemblages. The most common and widely distributed assemblages were not associated with substratum type, which we characterized as either hard or soft. The timing of hatch and larval growth separated the major groups in time and may have adaptive significance for the members of each major assemblage. The quality and locations (with reference to lake circulation) of spawning and nursery grounds may determine larval success and affect year class strength.

Drivers of Change in a 7300-Year Holocene Diatom Record from the Hemi-Boreal Region of Ontario, Canada.

Directory of Open Access Journals (Sweden)

Kristen K Beck

Full Text Available A Holocene lake sediment record spanning the past 7300 years from Wishart Lake in the Turkey Lakes Watershed in the Hemi-Boreal of central Ontario, Canada, was used to evaluate the potential drivers of long-term change in diatom assemblages at this site. An analysis of diatom assemblages found that benthic and epiphytic taxa dominated the mid-Holocene (7300-4000 cal yr BP, indicating shallow, oligotrophic, circum-neutral conditions, with macrophytes present. A significant shift in diatom assemblages towards more planktonic species (mainly Cyclotella sensu lato, but also several species of Aulacoseira, and Tabellaria flocculosa occurred ~4000 cal yr BP. This change likely reflects an increase in lake level, coincident with the onset of a more strongly positive moisture balance following the drier climates of the middle Holocene, established by numerous regional paleoclimate records. Pollen-inferred regional changes in vegetation around 4000 yrs BP, including an increase in Betula and other mesic taxa, may have also promoted changes in diatom assemblages through watershed processes mediated by the chemistry of runoff. A more recent significant change in limnological conditions is marked by further increases in Cyclotella sensu lato beginning in the late 19th century, synchronous with the Ambrosia pollen rise and increases in sediment bulk density, signaling regional and local land clearance at the time of Euro-Canadian settlement (1880 AD. In contrast to the mid-Holocene increase in planktonic diatoms, the modern increase in Cyclotella sensu lato likely indicates a response to land use and vegetation change, and erosion from the watershed, rather than a further increase in water level. The results from Wishart Lake illustrate the close connection between paleoclimate change, regional vegetation, watershed processes, and diatom assemblages and also provides insight into the controls on abundance of Cyclotella sensu lato, a diatom taxonomic group

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

Science.gov (United States)

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

1988-01-01

Lake Austin and Town Lake are located on the Colorado River in Travis County, central Texas, and serve as a source of water for municipal and industrial water supplies, electrical-power generation, and recreation for more than 500,000 people in the Austin metropolitan area. Lake Austin, located immediately downstream of Lake Travis, extends for more than 20 miles into the western edge of the city of Austin. Town Lake extends through the downtown area of the city of Austin for nearly 6 miles where the Colorado River is impounded by Longhorn Dam.

Current expansion of the Elliot Lake mines

International Nuclear Information System (INIS)

Stenning, G.

1982-06-01

The Elliot Lake mines are located in northern Ontario, on the north shore of Lake Huron. Mining operations in this area started in the mid-1950's and were curtailed during the 1960's. Starting in 1973 Rio Algom's Quirke mine and Denison, the only producers remaining in the area, started to make plans to expand. Increasing production to 30,000 tpd (milled) requires the reopening of the Panel and Stanleigh Mines of the Rio Algom group and the Stanrock-CanMet area at Denison. The first phase of the expansion was preceded by extensive public hearings. Mine production increases, improvement to the facilities at the reopened mines, and the effects on community facilities are described in this paper

Source-receptor relationships for speciated atmospheric mercury at the remote Experimental Lakes Area, northwestern Ontario, Canada

Directory of Open Access Journals (Sweden)

I. Cheng

2012-02-01

Full Text Available Source-receptor relationships for speciated atmospheric mercury measured at the Experimental Lakes Area (ELA, northwestern Ontario, Canada were investigated using various receptor-based approaches. The data used in this study include gaseous elemental mercury (GEM, mercury bound to fine airborne particles (<2.5 μm (PHg, reactive gaseous mercury (RGM, major inorganic ions, sulphur dioxide, nitric acid gas, ozone, and meteorological variables, all of which were measured between May 2005 and December 2006. The source origins identified were related to transport of industrial and combustion emissions (associated with elevated GEM, photochemical production of RGM (associated with elevated RGM, road-salt particles with absorption of gaseous Hg (associated with elevated PHg and RGM, crustal/soil emissions, and background pollution. Back trajectory modelling illustrated that a remote site, like ELA, is affected by distant Hg point sources in Canada and the United States. The sources identified from correlation analysis, principal components analysis and K-means cluster analysis were generally consistent. The discrepancies between the K-means and Hierarchical cluster analysis were the clusters related to transport of industrial/combustion emissions, photochemical production of RGM, and crustal/soil emissions. Although it was possible to assign the clusters to these source origins, the trajectory plots for the Hierarchical clusters were similar to some of the trajectories belonging to several K-means clusters. This likely occurred because the variables indicative of transport of industrial/combustion emissions were elevated in at least two or more of the clusters, which means this Hg source was well-represented in the data.

The Challenge (Goldcorp Inc.): prospección aurífera vía Internet. Aplicación del modelo de zona de cizalla aurífera a la mina Red Lake (Ontario, Canadá)

OpenAIRE

Oyarzun, Roberto; Castiñeiras García, Pedro; López Ruiz-Labranderas, Iván; Blanco García, Iván; Herrera, R.

2004-01-01

En marzo del 2000 la compañía canadiense Goldcorp Inc. invitó a geólogos de todo el mundo a presentar propuestas de exploración para su propiedad minera en Ontario (Red Lake mine). El concurso fue denominado “The Challenge”. Las propuestas tenían que: ser concisas, identificar objetivos específicos, estar sustentadas por un razonamiento geológico apropiado, y ser enviadas vía e-mail en inglés. Las propuestas podían ser presentadas por individuos o equipos. La información geológica so...

What fraction of the total metal flux into lakes is retained in the sediments

Energy Technology Data Exchange (ETDEWEB)

Nriagu, J O; Wong, H K.T.

1986-12-01

The concentrations of, and deposition rates for, the pollutant metals (Pb, Cu, Zn, Ni, and Cd) and the rare earth elements are reported for the sediments and settling particulates in a large, remote lake (Lake Opeongo) in the Algonquin Provincial Park, Ontario. Using a mass conservation model based on the rare earth elements, it is estimated that only 40 to 60% of pollutant metals getting into the lake is retained by the sediments. The low retention rate may explain the widely reported intrabasin and intra-lake differences in metal contents of sediments and casts some doubt on the use of pollutant metal profiles in retrospective assessment of the human contribution to the metal flux into many lake basins. 22 references.

Implications of climatic change for tourism and recreation in Ontario. Incidences du changement climatique sur le tourisme et les loisirs en Ontario; Sommaire de Phase 1 et 2. Le changement climatique et son incidence sur le tourisme et les loisirs en Ontario

Energy Technology Data Exchange (ETDEWEB)

Wall, G; Harrison, R; Kinnaird, V; McBoyle, G; Quinland, C

1988-01-01

Scenarios for climatic change associated with a doubling of atmospheric carbon dioxide were employed in an assessment of the impacts of climate change on tourism and recreation in Ontario. A warmer climate resulting from such change may mean declining lake levels with associated changes in the ecological interest and recreational potential of wetlands, as shown by case studies on two parks near Great Lakes shorelines. In the skiing industry, the length of ski seasons will be reduced in the northern part of the province, but the key holiday periods (when a large portion of total business is conducted) should still fall within the reliable ski season. Further south, the ski season in the South Georgian Bay region could be eliminated. Summer recreational activities are likely to have extended seasons, and the viability of summer recreational enterprises may increase, with associated positive benefits to neighboring communities. 2 refs., 6 figs., 3 tabs.

Ontario Hydro annual report 1985

International Nuclear Information System (INIS)

1986-04-01

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

Plutonium and americum concentration along fresh water food chains of the Great Lakes, U.S.A. General summary of progress, 1975--1976

International Nuclear Information System (INIS)

Bowen, V.T.

1976-01-01

Progress is reported for studies on the distribution of long-lived transuranic nuclides and 137 Cs introduced into the Great Lakes by fallout deposits or in radioactive effluents from nuclear facilities. Emphasis is placed on the content of 137 Cs, 241 Am, 239 Pu, 240 Pu, and 244 Cm in plankton, fish, and sediments sampled in Lake Erie and Lake Ontario during 1975 and 1976

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

Science.gov (United States)

Kammerer, P.A.

1996-01-01

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

Sensitization of a child to cyanobacteria after recreational swimming in a lake

Science.gov (United States)

We report a case of an 11 year-old white female who developed an allergic reaction after swimming in Lake Ontario, Canada. Specific IgE reactivity to various species of cyanobacteria extracts was found to be increased in the patient’s serum. This case emphasizes the importance of...

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

Seasonal and interannual effects of hypoxia on fish habitat quality in central Lake Erie

Science.gov (United States)

Arend, Kristin K.; Beletsky, Dmitry; DePinto, Joseph; Ludsin, Stuart A.; Roberts, James J.; Rucinski, Daniel K.; Scavia, Donald; Schwab, David J.; Höök, Tomas O.

2011-01-01

1. Hypoxia occurs seasonally in many stratified coastal marine and freshwater ecosystems when bottom dissolved oxygen (DO) concentrations are depleted below 2–3 mg O2 L-1. 2. We evaluated the effects of hypoxia on fish habitat quality in the central basin of Lake Erie from 1987 to 2005, using bioenergetic growth rate potential (GRP) as a proxy for habitat quality. We compared the effect of hypoxia on habitat quality of (i) rainbow smelt, Osmerus mordax mordax Mitchill (young-of-year, YOY, and adult), a cold-water planktivore, (ii) emerald shiner, Notropis atherinoides Rafinesque (adult), a warm-water planktivore, (iii) yellow perch, Perca flavescens Mitchill (YOY and adult), a cool-water benthopelagic omnivore and (iv) round goby Neogobius melanostomus Pallas (adult) a eurythermal benthivore. Annual thermal and DO profiles were generated from 1D thermal and DO hydrodynamics models developed for Lake Erie’s central basin. 3. Hypoxia occurred annually, typically from mid-July to mid-October, which spatially and temporally overlaps with otherwise high benthic habitat quality. Hypoxia reduced the habitat quality across fish species and life stages, but the magnitude of the reduction varied both among and within species because of the differences in tolerance to low DO levels and warm-water temperatures. 4. Across years, trends in habitat quality mirrored trends in phosphorus concentration and water column oxygen demand in central Lake Erie. The per cent reduction in habitat quality owing to hypoxia was greatest for adult rainbow smelt and round goby (mean: -35%), followed by adult emerald shiner (mean: -12%), YOY rainbow smelt (mean: -10%) and YOY and adult yellow perch (mean: -8.5%). 5. Our results highlight the importance of differential spatiotemporally interactive effects of DO and temperature on relative fish habitat quality and quantity. These effects have the potential to influence the performance of individual fish species as well as population dynamics

Environmental and zooplankton parameter changes during the drying of a saline shallow temporary lake in central Argentina

Directory of Open Access Journals (Sweden)

Alicia María Vignatti

2017-09-01

Full Text Available Central Argentina has numerous saline lakes sustained by groundwater sources and rainfall. These lakes are temporary and experience significant changes in water level and salinity, depending on wet and dry climate cycles. This study aims to investigate the scarcely known dynamics of environmental and zooplankton parameters during the drying phase of one of these lakes. Monthly samples were taken from December 2 012 to July 2 013 in the Ojo de Agua Uriburu lake, previous to its drying. At the beginning of the study, the lake’s depth was 0.7 m and its salinity was 16.65 g L−1, later, in July, its depth decreased to 0.06 m and its salinity increased to 92.9 g L−1. Zooplankton species richness was low (three crustaceans and three rotifers, with Boeckella poopoensis and Moina eugeniae dominating in the system. Maximum density and biomass were attained by the two dominant species in April (318.5 i nd L−1 and 3 029.1 µg L−1 dry weight; and 242.4 i nd L −1 and 1 530.4 µg L−1 dry weight, for B. poopoensis and M. ugeniae, respectively, and no correlation was found between these parameters and salinity. Maximum average body lengths for both species were observed in the last months of sampling (M. eugeniae: 1 020 ± 84.2 µm and B. poopoensis: 1 348.8 ± 89.0 µm. At this point of the study, neither juvenile nor larval stages were found. The increase in average body size is, arguably, the result of increased salinity in the system through a negative effect on reproduction. Because this lake reached hypersalinity, its ecological dynamics are unique among those of other temporary, saline lakes that dried in central Argentina. Similar studies on other temporary ecosystems are needed to increase the information on these little known ecological aspects.

Spatial characterization of acid rain stress in Canadian Shield Lakes

Science.gov (United States)

Tanis, Fred J.

1987-01-01

The acidification of lake waters from airborne pollution is of continental proportions both in North America and Europe. A major concern of the acid rain problem is the cumulative ecosystem damage to lakes and forest. The number of lakes affected in northeastern U.S. and on the Canadian Shield is though to be enormous. How seasonal changes in lake transparency are related to annual acidic load was examined. The relationship between variations in lake acidification and ecophysical units was also examined. The utility of Thematic Mapper based observations to measure seasonal changes in the optical transparency in acid lakes was investigated. The potential for this optical response is related to a number of local ecophysical factors with bedrock geology being, perhaps, the most important. Other factors include sulfate deposition, vegetative cover, and terrain drainage/relief. The area of southern Ontario contains a wide variety of geologies from the most acid rain sensitive granite quartzite types to the least sensitive limestone dolomite sediments. Annual sulfate deposition ranges from 1.0 to 4.0 grams/sq m.

Market surveillance in Ontario

International Nuclear Information System (INIS)

Chandler, H.

2002-01-01

On May 1, 2002 both wholesale and retail electricity markets in Ontario were opened to competition. Wholesale electricity market sales of 150 TWh were valued at over $11 billion with 27,500 MW in service installed capacity and 4,000 to 6,000 MW import/export capability with strong interconnections to the Quebec, the Midwest and the Northeast. The key players in Ontario's electricity market are the Ontario Energy Board (OEB), the Independent Electricity Market Operator (IMO), Ontario Power Generation, and Hydro One. The OEB regulatory framework includes licensing and front line, daily monitoring of whole sale market. Serious capacity problems in Ontario have manifested themselves in tight supply and demand situations and highly volatile prices. The paper included graphs of available reserves for 1996 to 2002, HOEP trends and frequency, HOEP comparison, and a sensitivity to demand forecast. 1 tab., 6 figs

Ontario electricity rates and industrial competitiveness

International Nuclear Information System (INIS)

2006-01-01

Industrial electricity prices in Ontario rose significantly after the opening of the competitive Ontario electricity market in 2002, thereby widening the gap between industrial electricity prices in Ontario and those in other Canadian provinces. Navigant Consulting Ltd. conducted this study at the request of the Association of Major Power Consumers in Ontario (AMPCO) to research and compare current and historical electricity prices in Ontario and other jurisdictions in North America. The study provided an independent analysis of how industrial electricity prices in Ontario compare to those in other jurisdiction in which AMPCO members operate. It also formed the basis for comparing the impacts of electricity policy on the economic competitiveness of major power consumers in Ontario. The relative electricity intensity in the United States, Ontario and other Canadian provinces was reviewed for specific industries, including forest products, steel manufacturing, petroleum refining, chemical manufacturing and cement manufacturing. Publicly available aggregate data from Statistics Canada and the United States Bureau of the Census was then used to compare average electricity prices for industrial customers in Ontario. The data confirmed that Ontario has experienced a decline in its competitive price advantage in industrial electricity. Delivered industrial electricity prices in Ontario have increased by more than 60 per cent since 2001. Industrial electricity prices in Ontario rose above those in Quebec, Manitoba, British Columbia and New Brunswick. In addition, industrial electricity prices in Ontario rose above those in competing states such as Ohio and Illinois, in part due to the increase in the value of the Canadian dollar. It was concluded that the price increase may lead to a greater decline in economic output in Ontario compared to competing jurisdictions. 2 tabs., 14 figs., 1 appendix

Ontario's Clean Air Action Plan : protecting environmental and human health in Ontario

International Nuclear Information System (INIS)

2004-01-01

Ontario's Clean Air Action Plan was launched in June 2000 in an effort to improve air quality and comply with the Canada-Wide Standards for Particulate Matter and Ozone. This paper describes Ontario's approach to reducing smog. Smog-related air pollution is linked to health problems such as premature death, respiratory and heart problems. Smog also contributes to environmental problems such as damage to forests, agricultural crops and natural vegetation. The two main ingredients of smog are ground level ozone and particulate matter. In order to reduce the incidence of smog, the following four key smog-causing pollutants must be reduced: nitrogen oxides, volatile organic compounds, sulphur dioxide and particular matter. This paper includes the 2001 estimates for Ontario's emissions inventory along with Ontario's smog reduction targets. It was noted that approximately half of all smog in Ontario comes from sources in the midwestern United States. The province of Ontario is committed to replacing coal-fired power plants with cleaner sources of energy. It is also considering emission caps for key industrial sectors. The key players in reducing smog include municipalities, industry, individuals, the federal government and programs that reduce emissions in the United States. 3 figs., 8 tabs., 1 appendix

Chemical evidences of the effects of global change in high elevation lakes in Central Himalaya, Nepal

Science.gov (United States)

Tartari, Gianni; Lami, Andrea; Rogora, Michela; Salerno, Franco

2016-04-01

It is well known that the lakes integrate the pressure of their surrounding terrestrial environment and the climatic variability. Both the water column and sediments are capable to accumulate signals of global change, such as warming of the deep layers or mutation of diverse biological records (e.g., fossil diatoms) and the nutrient loads variability affecting the trophic state. Typically, the biological responses to climate change have been studied in several types of lakes, while documented changes in water chemistry are much rare. A long term study of 20 high altitude lakes located in central southern Himalaya (Mt Everest) conducted since the 90s has highlighted a general change in the chemical composition of the lake water: a substantial rise in the ionic content was observed, particularly pronounced in the case of sulphate. In a couple of these lakes, monitored on an annual basis, the sulphate concentrations increased over 4-fold. A change in the composition of atmospheric wet deposition, as well as a possible influence of decrease in seasonal snow cover duration, which could have exposed larger basin surfaces to alteration processes, were excluded. The chemical changes proved to be mainly related to the sulphide oxidation processes occurring in the bedrocks or the hydrographic basins. In particular, the oxidation processes, considered as the main factor causing the sulphate increase, occurred in subglacial environments characterized by higher glacier velocities causing higher glacier shrinkage. Associated to this mechanism, the exposure of fresh mineral surfaces to the atmosphere may have contributed also to increases in the alkalinity of lakes. Weakened monsoon of the past two decades may have partially contributed to the solute enrichment of the lakes through runoff waters. The almost synchronous response of the lakes studied, which differs in terms of the presence of glaciers in their basins, highlights the fact that the increasing ionic content of lake

Contrasting evolution patterns between glacier-fed and non-glacier-fed lakes in the central Tibetan Plateau and driving force analysis

Science.gov (United States)

Song, C.; Sheng, Y.

2015-12-01

High-altitude lakes in the Tibetan Plateau (TP) showed strong spatio-temporal variability during past decades. The lake dynamics can be associated with several key factors including lake type, supply of glacial meltwater, local climate variations. It is important to differentiate these factors when analyzing the driving force of lakes dynamics. With a focus on lakes over the Tanggula Mountains of the central TP, this study investigates the temporal evolution patterns of lake area and water level of different types: glacier-fed closed lake, non-glacier-fed closed lake and upstream lake (draining into closed lakes). We collected all available Landsat archive data and quantified the inter-annual variability of lake extents. Results show accelerated expansions of both glacier-fed and non-glacier-fed lakes during 1970s-2013, and different temporal patterns of the two types of lakes: the non-glacier-fed lakes displayed a batch-wise growth pattern, with obvious growth in 2002, 2005 and 2011 and slight changes in other years, while glacier-fed lakes showed steady expanding tendency. The contrasting patterns are confirmed by the distinction of lake level change between the two groups derived from satellite altimetry during 2003-2009. The upstream lakes remained largely stable due to natural drainage regulation. The intermittent expansions for non-glacier-fed lakes were found to be related to excessive precipitation events and positive "precipitation-evaporation". In contrast, glacier-fed lake changes showed weak correlations with precipitation variations, which imply a joint contribution from glacial meltwater to water budgets. A simple estimation reveals that the increased water storage for all of examined lakes contributed from precipitation/evaporation (0.31±0.09 Gt/yr) slightly overweighed the glacial meltwater supply (0.26±0.08 Gt/yr).

Ontario Hydro's DSP update

International Nuclear Information System (INIS)

Anon.

1992-01-01

Ontario Hydro's Demand/Supply Plan (DSP), the 25 year plan which was submitted in December 1989, is currently being reviewed by the Environmental Assessment Board (EAB). Since 1989 there have been several changes which have led Ontario Hydro to update the original Demand/Supply Plan. This information sheet gives a quick overview of what has changed and how Ontario Hydro is adapting to that change

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

Science.gov (United States)

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

2016-05-17

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

Characterization of photoautotrophic picoplankton assemblages in turbid, alkaline lakes of the Carpathian Basin (Central Europe

Directory of Open Access Journals (Sweden)

Lajos VÖRÖS

2009-08-01

Full Text Available The photoautotrophic picoplankton (PPP of ten shallow, hyposaline soda lakes located in three different geographical regions in the Carpathian Basin (Central Europe was characterized. These lakes, which frequently dry out completely, are extremely rich in PPP. Epifluorescence microscopy was applied to determine picocyanobacterial and picoeukaryotic cell abundance and PCR-based molecular techniques (denaturing gradient gel electrophoresis and cloning with phylospecies delineation to identify the members of PPP. Most of these lakes were eu- and hypertrophic with varying contribution of picocyanobacteria to the total PPP cell number. We found an unusually high PPP abundance with peaks of 8.16 × 106 cells mL-1 for picoeukaryotes and 1.78 × 107 cells mL-1 for picocyanobacteria. The majority of the retrieved PPP sequences belonged to picocyanobacteria (nonmarine Synechococcus/ Cyanobium, while others showed similarity to eukaryotic algal plastids (close to Trebouxiophycean isolates. Molecular analysis revealed significant genetic diversity in the PPP fraction of these lakes and showed that the closest relatives of our picocyanobacterial clones were recovered from different habitats, indicating seemingly no correlation between the 'saline' ecotypes and their phylogenetic position. Our results also confirmed that PPP might exploit different aquatic ecosystems and be successful even in the case of abrupt changes of environmental parameters (in our case, salinity. According to our knowledge, this is the first survey focusing on the identification of the PPP community members in turbid and alkaline lakes with extraordinarily high picoplankton productivity.

Activities and results of the terrestrial effects program: acid precipitation in Ontario study (Apios)

Energy Technology Data Exchange (ETDEWEB)

Linzon, S N

1986-11-01

Studies on the terrestrial effects of acidic precipitation in Ontario involve determining the effects on soils, crops, forests, lichens, mosses and biogeochemical systems. In the soils program, a baseline study was started in 1980 to establish a reliable and uniform data base for soils across the province, in order to identify future trends. Soil sensitivity criteria are being derived for mapping purposes. Starting in 1982, a complex, sophisticated mobile rain exclusion canopy system was constructed outdoors for controlled acid rain studies to determine the dose-response relationships of field crops. In response to numerous complaints a program was designed to determine the role that acidic precipitation is playing in the decline of sugar maple trees in Ontario. At 8 sites, tree conditions were noted, samples of foliage, bark, roots and soil were collected for chemical analysis, and increment cores and discs (from felled trees) were taken for radial growth patterns. Results from this study indicated that acidic precipitation was an additional stress to insect outbreaks and spring droughts. Intensive surveys have been conducted in selected areas in Ontario to identify the current viability and distribution of common denominator lichens and mosses. Biogeochemical studies are being conducted at four watersheds in Ontario. The different watersheds are located in progressively decreasing atmospheric deposition loadings from east to west across the province. The studies are attempting to document the role of contrasting terrestrial ecosystems in the process of lake acidification by atmospheric deposition. 9 references.

Rehabilitation of Mohawk Lake: Brantford's crown jewel

International Nuclear Information System (INIS)

Farrell, C.W.; Kube, D.J.

1994-01-01

Mohawk Lake in Brantford, Ontario had been receiving contaminants from various industrial and municipal sources since the late 1800s. The lake suffered a slow death with the absence of any watershed management plan. A citizen committee was established in 1990 to rehabilitate the lake so that its recreational and resource potential could be fully realized. In 1993, the committee obtained government funding to carry out a detailed baseline environmental study of the lake. Lake sediments were found to consist of an upper horizon of poorly consolidated, organic-rich, odoriferous material overlying a more compact sandy layer. Lake water was characterized by high concentrations of nutrients and metals, and high biological oxygen demand. Sediments also had high concentrations of heavy metals and low concentrations of such organic contaminants as pyrene, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls. The most distinct contaminant appeared to be petroleum hydrocarbons at 0.5-1% concentration. It was determined that lake rehabilitation would require removal of these sediments. Tests indicated that the sediments were non-hazardous non-registrable solid waste, and the preferred removal option was hydraulic dredging into settlement ponds along the undeveloped south shore of the lake. A sediment trap was recommended to be installed at the entrance of the lake, along with a constructed wetland to remove a variety of water pollutants. The sediment dredging, dewatering, trap and wetland installation, and land remediation of the sediment disposal area are estimated to cost ca $3.75 million, and the work will require at least 18 months to complete. 1 fig

Holocene Lake-Level Fluctuations of Lake Aricota, Southern Peru

Science.gov (United States)

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

2001-09-01

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

Ontario electricity industry restructuring

International Nuclear Information System (INIS)

1999-01-01

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

Quartz-molybdenite veins in the Priestly Lake granodiorite, north-central Maine

Science.gov (United States)

Ayuso, Robert A.; Shank, Stephen G.

1983-01-01

Quartz-molybdenite veins up to 15 cm in width occur in fine to medium-grained porphyritic biotite-hornblende granodiorite at Priestly Lake north-central Maine. An area of about 150 m x 150 m contains quartz-molybdenite veins; a larger area is characterized by barren quartz veins. Quartz-molybdenite veins are concentrated within the most felsic variants of the intrusion as suggested by lower mafic mineral contents. The pluton has a narrow range in SiO2 (67-70 wt.%), major oxides, and in trace-element compositions. Molybdenite occurs as coarse grained clusters in pockets within the quartz veins, and fills fractures in the quartz veins and host rocks. Disseminated molybdenite in the granodiorite is relatively rare and occurs only in the area characterized by a high density of quartz veins (up to 50 veins per square meter). Alteration envelopes along the quartz veins are very thin or absent, although in some areas the granodiorite appears to be selectively and pervasively altered. Sericite, chlorite, epidote, calcite, pyrite, and quartz are concentrated near the quartz-molybdenite veins. Many of the field and geochemical characteristics of the Priestly Lake pluton are unlike those of major molybdenum-producing areas (Climax, Henderson, Urad). For example, the area of alteration seems to be of limited extent, the host rock is not intensely altered hydrothermally at the surface, the density of fractures is rather low in the mineralized area, and the amount of disseminated molybdenite appears to be small. However, the Priestly Lake pluton may be a small fraction of a concealed batholith as suggested by geophysical data. It is conceivable that the type of mineralization at the surface might be the expression of more extensive molybdenite mineralization at depth. The quartz-molybdenite veins in the Priestly Lake pluton are significant because they indicate that potential molybdenum sources for producing mineralized granites were available at depth. Future studies should be

Challenges in understanding, modelling, and mitigating Lake Outburst Flood Hazard: experiences from Central Asia

Science.gov (United States)

Mergili, Martin; Schneider, Demian; Andres, Norina; Worni, Raphael; Gruber, Fabian; Schneider, Jean F.

2010-05-01

Lake Outburst Floods can evolve from complex process chains like avalanches of rock or ice that produce flood waves in a lake which may overtop and eventually breach glacial, morainic, landslide, or artificial dams. Rising lake levels can lead to progressive incision and destabilization of a dam, to enhanced ground water flow (piping), or even to hydrostatic failure of ice dams which can cause sudden outflow of accumulated water. These events often have a highly destructive potential because a large amount of water is released in a short time, with a high capacity to erode loose debris, leading to a powerful debris flow with a long travel distance. The best-known example of a lake outburst flood is the Vajont event (Northern Italy, 1963), where a landslide rushed into an artificial lake which spilled over and caused a flood leading to almost 2000 fatalities. Hazards from the failure of landslide dams are often (not always) fairly manageable: most breaches occur in the first few days or weeks after the landslide event and the rapid construction of a spillway - though problematic - has solved some hazardous situations (e.g. in the case of Hattian landslide in 2005 in Pakistan). Older dams, like Usoi dam (Lake Sarez) in Tajikistan, are usually fairly stable, though landsildes into the lakes may create floodwaves overtopping and eventually weakening the dams. The analysis and the mitigation of glacial lake outburst flood (GLOF) hazard remains a challenge. A number of GLOFs resulting in fatalities and severe damage have occurred during the previous decades, particularly in the Himalayas and in the mountains of Central Asia (Pamir, Tien Shan). The source area is usually far away from the area of impact and events occur at very long intervals or as singularities, so that the population at risk is usually not prepared. Even though potentially hazardous lakes can be identified relatively easily with remote sensing and field work, modeling and predicting of GLOFs (and also

Initial Time Of Two High Altitude Crater Lakes (Nevado De Toluca, Central Mexico Recorded In Subfossil Cladocera

Directory of Open Access Journals (Sweden)

Szeroczyńska Krystyna

2015-12-01

Full Text Available The objective of this study was the recognition and reconstruction of the origin of two high altitude lakes and the ecological conditions of their early existence based on subfossil Cladocera and chemical analyses. The study focused on the oldest lacustrine sediments from Lake Sol and Lake Luna, located in the crater of Volcano Nevado de Toluca (Central Mexico. The Nevado de Toluca crater developed approximately 12 ka yr BP. According to the literature, the volcano was last active approximately 3.3 ka yr BP, and the lakes developed after that eruption. The remains of nine Cladocera species were found in the bottom sediments of both lakes. The most dominant taxa were two endemic littoral species: Alona manueli and Iliocryptus nevadensis. The total frequency of Cladocera specimens in both of the sediment cores was very low. No Cladocera remains were recorded in the sediment layer at depths between 123–103 m from Lake Luna. The results of the lithological and geochemical analyses showed that this sediment layer was composed of allochthonous material, probably originating from slid down from the volcanic cone. This was suggested by the content of silica (up to 13%, iron (up to 12%, and titanium (up to 4%. The Cladocera remains recorded in the bottom sediments suggested that both reservoirs developed as freshwater lakes at the beginning of the sedimentation. The calibrated radiocarbon dates obtained for the bottom samples were 4040 to 3990 yr BP for Lake Luna (129 cm and 4485 to 4485 yr BP for Lake Sol (89 cm. The obtained ages were older than the dates of the last eruption, which occurred approximately 3300 yr BP. This result was likely related to the type of radiocarbon dated materials (charcoals.

Plutonium and americium in Lake Michigan sediments

International Nuclear Information System (INIS)

Edgington, D.N.; Alberts, J.J.; Wahlgren, M.A.; Karttunen, J.O.; Reeve, C.A.

1975-01-01

The vertical distributions of 239 , 240 Pu, 238 Pu, and 137 Cs have been measured in sediment cores taken from Lake Michigan. Sections from a limited number of cores have been analyzed for 241 Am. In addition, grab samples from ten locations in the southern basin of the lake have been analyzed for phase distribution of 239 , 240 Pu using a sequential extraction technique. The results indicate that the 239 , 240 Pu, 238 Pu, and 137 Cs from weapons testing, and the 241 Am formed in situ are concentrated in the sediments. A comparison of the total deposition of 239 , 240 Pu and 137 Cs indicates that 137 Cs may be valuable as a monitor for 239 , 240 Pu deposition in the sediments. Values of the 238 Pu/ 239 , 240 Pu ratio are in agreement with values reported in Lake Ontario sediments (and Lake Michigan plankton) and show little variation with depth. 241 Am data support the concept of in situ production with little preferential mobility after formation. Studies of sedimentary phase distributions show that 239 , 240 Pu is associated with hydrous oxide phases which are chemically stable under the prevailing conditions in lake sediments. Since Lake Michigan sediments remain aerobic, relatively little 239 , 240 Pu is available for chemical mobilization from the hydrous oxide or organic phases present in the sediments

Effects of recharge, Upper Floridan aquifer heads, and time scale on simulated ground-water exchange with Lake Starr, a seepage lake in central Florida

Science.gov (United States)

Swancar, Amy; Lee, Terrie Mackin

2003-01-01

Lake Starr and other lakes in the mantled karst terrain of Florida's Central Lake District are surrounded by a conductive surficial aquifer system that receives highly variable recharge from rainfall. In addition, downward leakage from these lakes varies as heads in the underlying Upper Floridan aquifer change seasonally and with pumpage. A saturated three-dimensional finite-difference ground-water flow model was used to simulate the effects of recharge, Upper Floridan aquifer heads, and model time scale on ground-water exchange with Lake Starr. The lake was simulated as an active part of the model using high hydraulic conductivity cells. Simulated ground-water flow was compared to net ground-water flow estimated from a rigorously derived water budget for the 2-year period August 1996-July 1998. Calibrating saturated ground-water flow models with monthly stress periods to a monthly lake water budget will result in underpredicting gross inflow to, and leakage from, ridge lakes in Florida. Underprediction of ground-water inflow occurs because recharge stresses and ground-water flow responses during rainy periods are averaged over too long a time period using monthly stress periods. When inflow is underestimated during calibration, leakage also is underestimated because inflow and leakage are correlated if lake stage is maintained over the long term. Underpredicted leakage reduces the implied effect of ground-water withdrawals from the Upper Floridan aquifer on the lake. Calibrating the weekly simulation required accounting for transient responses in the water table near the lake that generated the greater range of net ground-water flow values seen in the weekly water budget. Calibrating to the weekly lake water budget also required increasing the value of annual recharge in the nearshore region well above the initial estimate of 35 percent of the rainfall, and increasing the hydraulic conductivity of the deposits around and beneath the lake. To simulate the total

Meeting Ontario's electricity needs : a critical review of the Ontario Power Authority's supply mix advice report

International Nuclear Information System (INIS)

Gibbons, J.; Fracassi, J.

2006-01-01

In December, 2005 the Ontario Power Authority (OPA) outlined its proposed blueprint for meeting Ontario's electricity needs to 2025 in the document entitled Supply Mix Advice Report. As a result of the actions taken by the current government, the OPA believes that Ontario will have adequate electricity supplies to meet the province's needs until 2013. However, it stated that Ontario will require an additional 15,000 megawatts of new generation capacity between 2013 and 2025. The OPA also recommends that a significant proportion of this new generation capacity be nuclear. The Ontario Clean Air Alliance undertook a review of the OPA report and identified several discrepancies including an over-estimation of Ontario's rate of electricity load growth from 2005 to 2025; an under-estimation of the potential for electricity productivity improvements to reduce electricity demand and raise living standards; an under-estimation of renewable energy supply potential; an under-estimation of the potential for biomass and natural gas fired combined heat and power plants to meet electricity needs and increase the competitiveness of Ontario's industries; an under-estimation of the economic costs and risks of nuclear power; and a biased recommendation for a 70 million dollar resource acquisition budget against energy efficiency investments that would reduce demand and raise living standards. This report provides the Ontario Clean Air Alliances' analysis of the OPA report and presents it own recommendations for how Ontario can increase its electricity productivity and meet its electricity supply needs until 2025. The report concluded that the Government of Ontario should direct the OPA to develop a long-term strategy to raise the price of electricity up to its full cost without raising the electricity bills of low income consumers or impairing the competitiveness of Ontario's industries. It was suggested that Ontario's electricity productivity should be increased to the same level as

Quick Release of Internal Water Storage in a Glacier Leads to Underestimation of the Hazard Potential of Glacial Lake Outburst Floods From Lake Merzbacher in Central Tian Shan Mountains

Science.gov (United States)

Shangguan, Donghui; Ding, Yongjian; Liu, Shiyin; Xie, Zunyi; Pieczonka, Tino; Xu, Junli; Moldobekov, Bolot

2017-10-01

Glacial meltwater and ice calving contribute to the flood volume of glacial lakes such as Lake Merzbacher in the Tian Shan Mountains of central Asia. In this study, we simulated the lake's volume by constructing an empirical relationship between the area of Lake Merzbacher, determined from satellite images, and the lake's water storage, derived from digital elevation models. Results showed that the lake water supply rate before Glacial Lake Outburst Floods (GLOFs) generally agreed well with those during the GLOFs from 2009 to 2012 but not in 2008 and 2015. Furthermore, we found that the combination of glacial meltwater and ice calving is not enough to fully explain the supply rate during GLOFs in 1996 and 1999, suggesting other factors affect the supply rate during GLOFs as well. To examine this further, we compared the water supply rate before and during GLOF events in 1999 and 2008. We inferred that quickly released short-term and intermediate-term water storage by glaciers have likely contributed to both flood events in those years. This study highlights the need to improve our understanding of the supply component of outburst floods, such as irregularly released stored water may lead to GLOF events with generally three different types: case I (singular event-triggered englacial water release), case II (glacier melt due to temperature changes), and case III (englacial water release mixed with glacier melt).

An integrated investigation of lake storage and water level changes in the Paiku Co basin, central Himalayas

Science.gov (United States)

Lei, Yanbin; Yao, Tandong; Yang, Kun; Bird, Broxton W.; Tian, Lide; Zhang, Xiaowen; Wang, Weicai; Xiang, Yang; Dai, Yufeng; Lazhu; Zhou, Jing; Wang, Lei

2018-07-01

Since the late 1990s, lakes in the southern Tibetan Plateau (TP) have shrunk considerably, which contrasts with the rapid expansion of lakes in the interior TP. Although these spatial trends have been well documented, the underlying hydroclimatic mechanisms are not well understood. Since 2013, we have carried out comprehensive water budget observations at Paiku Co, an alpine lake in the central Himalayas. In this study, we investigate water storage and lake level changes on seasonal to decadal time scales based on extensive in-situ measurements and satellite observations. Bathymetric surveys show that Paiku Co has a mean and maximum water depth of 41.1 m and 72.8 m, respectively, and its water storage was estimated to be 109.3 × 108 m3 in June 2016. On seasonal scale between 2013 and 2017, Paiku Co's lake level decreased slowly between January and May, increased considerably between June and September, and then decreased rapidly between October and January. On decadal time scale, Paiku Co's lake level decreased by 3.7 ± 0.3 m and water storage reduced by (10.2 ± 0.8) × 108 m3 between 1972 and 2015, accounting for 8.5% of the total water storage in 1972. This change is consistent with a trend towards drier conditions in the Himalaya region during the recent decades. In contrast, glacial lakes within Paiku Co's basin expanded rapidly, indicating that, unlike Paiku Co, glacial meltwater was sufficient to compensate the effect of the reduced precipitation.

Managing inherent complexity for sustainable walleye fisheries in Lake Erie

Science.gov (United States)

Roseman, Edward F.; Drouin, Richard; Gaden, Marc; Knight, Roger; Tyson, Jeff; Zhao, Yingming; Taylor, William W.; Lynch, Abigail J.; Léonard, Nancy J.

2012-01-01

In Lake Erie, Walleye (Sander vitreus vitreus) is king. The naturally occurring species is the foundation of commercial fishing operations on the Canadian side of the lake and is a much-prized sport fish on the American side. Management of Lake Erie walleye fisheries is complex and takes place in an inter-jurisdictional setting composed of resource agencies from the states of Michigan (MDNR), Ohio (ODNR), Pennsylvania (PFBC), and New York (NYDEC) and the province of Ontario (OMNR). The complexity of walleye management is exacerbated by interactions among environmental and ecological changes in Lake Erie, complex life-history characteristics of the species, public demand for walleye, and cultural/governance differences among managing groups and their respective constituents. Success of future management strategies will largely hinge upon our ability to understand these inherent complexities and to employ tactics that successfully accommodate stock productivity and human demand in a highly dynamic environment. In this report, we review the history of Lake Erie walleye management, outline the multi-jurisdictional process for international management of walleye, and discuss strategies to address challenges facing managers.

Analysis of operating criteria: Multiple lakes at Voyageurs National Park

International Nuclear Information System (INIS)

Flug, M.; Kallemeyn, L.W.

1993-01-01

An overview of lake and river regulation at Voyageurs National Park, which resides on the Minnesota-Ontario border, is given to demonstrate how water policy agreements can work. In 1905 the United States and Canada authorized private dams with turbines on the Rainy River. The International Joint Commission regulates these dams. The National Park Service is mandated to preserve the natural environment for future generations. State, private, and public sector interests are tourism, flood protection, the pulp and paper industry, native wild rice growth; etc. Rule curves for regulating reservoirs have changed and committee with broad representation is cooperating to better manage the waters of Namakan Reservoir and Rainy Lake

Monitoring of Bashkara glacial lakes (the Central Caucasus) and modelling of their potential outburst.

Science.gov (United States)

Krylenko, I.; Norin, S.; Petrakov, D.; Tutubalina, O.; Chernomorets, S.

2009-04-01

In recent decades due to glacier retreat the glacial lakes in the Central Caucasus, as well as in other high-mountainous areas of the world, have expanded intensively. As result the risk of lake outbursts and destructive floods is raising. In this paper we present one of the most potentially hazardous lakes of this region - a group of glacial lakes near the Bashkara glacier in the upper Adylsu river valley, to the southeast of Mt. Elbrus. Total area of these lakes is about 100,000m2, and a total volume exceeds 1,000,000 m3. The biggest of them - the Bashkara lake has formed in late 1930s - early 1940s and the small Lapa lake has appeared in the end of 1980s. The Bashkara lake outburst occurred twice in the end of 1950s and produced devastating debris flows of ca. 2 million m3. We have monitored these lakes since 1999. Our work includes detailed field research: constant measurements of water level during warm period, annually repeated bathymetric surveys, geodetic surveys, observations on dam condition and some special measurements (i.e. water temperature distribution, current velocity). Also we use aerial and satellite images to obtain data about dynamic of areas for the lakes. From 2001 to 2006 years volume of the Lapa lake has increased 5 times (from 30,000 m3 to 140,000 m3), the Bashkara lake in this period was quasi-stable. In 2006-2008 volume of the Lapa lake has decreased due to sedimentation, however, rapid growth of water level in Bashkara lake (more than 20 sm. per day) has suddenly begun. As a result, volume of the Bashkara lake exceeded 1,000000 m3 in July 2008 whereas in 2001 -2007 year it was about 800,000 m3. Previous maximum of water level was exceeded on 3,5 m, moraine dam with ice core was overtopped and overflow has started. Thus, Bashkara glacier lakes are unstable and risk of outburst is increasing. To assess parameters and zones of potential outburst flood in the Adylsu River valley we have carried out hydrodynamic simulation. Two computer

The quantification and distribution of pollution Pb at a woodland in rural south central Ontario, Canada

International Nuclear Information System (INIS)

Watmough, Shaun A.; Hutchinson, Thomas C.

2004-01-01

Lead concentrations and Pb isotope ratios were measured in the forest floor, mineral soil and vegetation at a white pine and a sugar maple stand in a woodland in south central Ontario. Lead concentrations decreased and 206 Pb/ 207 Pb ratios increased with mineral soil depth reflecting the mixing of pollution and natural Pb sources. Lead concentrations and 206 Pb/ 207 Pb ratios at 20-30 cm depth were ∼6-7 mg/kg and 1.31-1.32, respectively. Assuming an integrated 206 Pb/ 207 Pb ratio in deposition over time of 1.18, estimated from lichen measurements and published data for the region, approximately 65% of Pb in the surface (0-1 cm) mineral soil is from anthropogenic sources. Approximately 90% of pollution Pb is found in the 0-10 cm soil layer (Ah) and less than 3% of the pollution Pb is present in the forest biomass and mull-type forest floor combined. Despite low Pb concentrations in vegetation ( 2 , respectively. - The distribution of pollution lead was determined at a woodland through the use of stable leads isotopes

Ontario Hydro statistical yearbook 1990

International Nuclear Information System (INIS)

1990-01-01

Ontario Hydro was created in 1906 by a special statute of the Province of Ontario. It is a financially self-sustaining corporation without share capital. The yearbook is a compilation of financial data detailed by financial statements and sales and revenue figures for the year 1990. It is broken down by municipalities served in Ontario

Ontario Hydro statistical yearbook 1990

Energy Technology Data Exchange (ETDEWEB)

NONE

1991-12-31

Ontario Hydro was created in 1906 by a special statute of the Province of Ontario. It is a financially self-sustaining corporation without share capital. The yearbook is a compilation of financial data detailed by financial statements and sales and revenue figures for the year 1990. It is broken down by municipalities served in Ontario.

Increased microsporidian parasitism of the crayfish Orconectes virilis in an experimentally acidified lake. [Thelohania contejeani

Energy Technology Data Exchange (ETDEWEB)

France, R.L.; Graham, L.

1985-10-01

Orconectes virilis has been identified as a host of the microsporidian Thelohania contejeani in four lakes in the Experimental Lakes Area (ELA), northwestern Ontario. Prevalence of parasitism increased from 1.7% in autumn 1979, to 6.5% and 7.7% in autumns 1980 and 1981 concomitant with experimental acidification of Lake 223 to pH 5.1. By comparison, mean infection rates observed within three reference lakes were between 0.3 to 0.6%. Enhanced microsporidosis is believed to have contributed to a reduction in annual crayfish survival rates for the Lake 223 population of 8% in 1979 and 18% in 1980 compared to averages calculated for the non-acidified lakes. Hypotheses to explain the ten-fold increase in Thelohania parasitism in Lake 223 over background levels for the ELA region include a) increased probagative ability due to elevated rate of crayfish cannibalism or low pH-favored parasite life cycle, and b) decreased host resistance when under sublethal stress.

Structural Evolution of central part of the Tuzgolu (Salt Lake) Basin, Central Anatolia, Turkey

Science.gov (United States)

Ada, M.; Cemen, I.; Çaptuğ, A.; Demirci, M.; Engin, C.

2017-12-01

The Tuzgolu Basin in Central Anatolia, Turkey, covers low-relief areas located between the Pontide Mountains to the North and Tauride Mountains to the South. The basin started to form as a rift basin during the Late Maastrichtian. The main Tuzgolu-Aksaray fault zone on the eastern margin of the basin and the northwest trending Yeniceoba and Cihanbeyli fault zones on the western margin of the basin were probably developed during that time. The basin has also experienced westward extension in response to westward escape of the Anatolian plate since Late Miocene. Several geologic studies have been conducted in the Tuz Gölü (Salt Lake) Basin and surrounding areas to determine structural and tectono-stratigraphic development of the basin. However, there are still many questions regarding the structural evolution of the basin. The main purpose of this study is to investigate the structural evolution of the central Tuzgolu Basin based on the structural interpretation of available 2-D seismic reflection profiles, well log analysis and construction of structural cross sections. The cross-sections will be based on depth converted seismic lines to determine structural geometry of the faults and folds. A preliminary Petrel project has been prepared using available seismic profiles. Our preliminary structural interpretations suggest that a well-developed rollover anticline was developed with respect to the westward extension in Central Anatolia. The rollover anticline is faulted in its crest area by both down-to-the west and down-to-the east normal faults. The geometry of the main boundary fault at depth still remains in question. We anticipate that this question will be resolved based on depth converted structural cross-sections and their restoration.

[Ontario Hydro]. Corporate performance report, 1994

International Nuclear Information System (INIS)

1995-01-01

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

Great Lakes Research Review, 1982. Appendices.

Science.gov (United States)

1982-11-01

7D-i53 28 GREAT LAKES RESEARCH REVIEW 1982 PPENDICES (U) / PETROLEUM REFINERY PO INT SOURCE TASK FORCE WINDSOR (ONTARIO) NOV 82UNCLASSIFIED F/G 8...C7 U. 3 X 7 45 1 2 0. ODm C of. C.’ WC.’ L. LI 7 R-Ri53 62B GREAT LKES RESEARCH REVIEW 1982 PPENDICES (U) 2/3 PETROLEUM REFINERY POINT SOURCE TASK...NUMBER ORGANIZATION* TITLE OF PROJECT 001 A** 0300 ERL-D Acute and Early Life Stage Toxicity Testing of Priority Pollutant Chemicals 002 A 0302 ERL-D

Ontario Hydro's integrated air management plan

International Nuclear Information System (INIS)

Kalvins, A.K.; Brown, D.; Camacho, F.; Howes, H.; Jantzi, B.; Lin, X.; Lui, P.; Melo, O.T.; Mortimer, W.P.; Reuber, B.

1992-01-01

Ontario Hydro is developing an integrated air management plan as a tool for comparing the environmental impacts of fossil-fuel power generation options. The goal is to relate equipment, location, emissions, and impacts and to identify the optimum way to manage the utility's fossil generation system in view of upcoming environmental regulations and public expectations. The eight steps of the plan are briefly described: definition of power generation scenarios (upgrading, conversion to natural gas, non-utility generation, alternative technologies); estimation of emissions for each generation and fuel option studied; identification of impact of air emissions on building materials, agriculture, forests, lakes, and fisheries; modelling of air emissions dispersion; quantification of damage to pollution receptors; quantification of full fuel cycle effects; and comparison of the scenarios. The scenario having the lowest overall environmental impact involved upgrading the existing fossil-fuel system with additional air emissions controls and two integrated gasification combined cycle plants. 9 refs., 3 figs., 3 tabs

Distribution and interannual variability of supraglacial lakes on debris-covered glaciers in the Khan Tengri-Tumor Mountains, Central Asia

International Nuclear Information System (INIS)

Qiao, Liu; Mayer, Christoph; Liu, Shiyin

2015-01-01

Supraglacial lakes are widely formed on debris-covered glaciers in the Khan Tengri-Tumor Mountains (KTTM), Tianshan, Central Asia. Study of their distribution characters based on regional-wide remote sensing investigations is still lacking, but it can promote our understanding about the influence of supraglacial lakes on the surface melting, hydrology and dynamics of debris-covered glaciers in this region. This study presents results of the supraglacial lake inventory in the KTTM region, based on multi-year Landsat images. We focus on the glacio-geomorphological characters of the supraglacial lakes and their late summer conditions, since all suitable Landsat images were acquired between August and September during 1990–2011. With a minimum threshold extent of 3600 m 2 for conservative mapping results, we totally mapped 775 supraglacial lakes and 38 marginal glacial lakes on eight huge debris-covered glaciers. Supraglacial lakes are concentrated on the Tumor Glacier and the South Inylchek Glacier, two biggest glaciers in this region. Although most supraglacial lakes are short-lived, a number of lakes can be repeatedly identified between different Landsat images. Detailed investigation of these ‘perennial’ lakes on the Tumor Glacier indicates that their filling frequency and area contributions have increased since 2005. Analysis of the area-elevation distributions for all mapped supraglacial lakes shows that they predominantly occur close to the altitude of 3250 m a.s.l., as high as the lowest reach of clean ice where surface debris begins to appear, and can further develop upglacier to a limit of about 3950 m a.s.l.. Total and mean area of supraglacial lakes in the KTTM region during the late summer seasons show great variability between years. Correlation analysis between the annual lake area and the observed nearby meteorological conditions suggests that warmer springs seem related to the draining of some supraglacial lakes during the following seasons, due

Water Quality and Evaluation of Pesticides in Lakes in the Ridge Citrus Region of Central Florida

Science.gov (United States)

Choquette, Anne F.; Kroening, Sharon E.

2009-01-01

Water chemistry, including major inorganic constituents, nutrients, and pesticide compounds, was compared between seven lakes surrounded by citrus agriculture and an undeveloped lake on the Lake Wales Ridge (herein referred to as the Ridge) in central Florida. The region has been recognized for its vulnerability to the leaching of agricultural chemicals into the subsurface due to factors including soils, climate, and land use. About 40 percent of Florida's citrus cultivation occurs in 'ridge citrus' areas characterized by sandy well drained soils, with the remainder in 'flatwoods citrus' characterized by high water tables and poorly drained soils. The lakes on the Ridge are typically flow-through lakes that exchange water with adjacent and underlying aquifer systems. This study is the first to evaluate the occurrence of pesticides in lakes on the Ridge, and also represents one of the first monitoring efforts nationally to focus on regional-scale assessment of current-use pesticides in small- to moderate-sized lakes (5 to 393 acres). The samples were collected between December 2003 and September 2005. The lakes in citrus areas contained elevated concentrations of major inorganic constituents (including alkalinity, total dissolved solids, calcium, magnesium, sodium, potassium, chloride, and sulfate), total nitrogen, pH, and pesticides compared to the undeveloped lake. Nitrate (as N) and total nitrogen concentrations were typically elevated in the citrus lakes, with maximum values of 4.70 and 5.19 mg/L (milligrams per liter), respectively. Elevated concentrations of potassium, nitrate, and other inorganic constituents in the citrus lakes likely reflect inputs from the surficial ground-water system that originated predominantly from agricultural fertilizers, soil amendments, and inorganic pesticides. A total of 20 pesticide compounds were detected in the lakes, of which 12 compounds exceeded the standardized reporting level of 0.06 ug/L (microgram per liter). Those

Canada's Response to the Recommendations in the Tenth Biennial Report on Great Lakes Water Quality of the International Joint Commission

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

The Government of Canada and Ontario are currently renegotiating the Canada-Ontario Agreement Respecting the Great Lakes Basin Ecosystem (COA). They are committed to restoring and maintaining the basin's chemical, physical and biological integrity and ensuring that it has a healthy, sustainable future. The COA has established a strategic framework for coordinated federal-provincial responsibilities regarding the Great Lakes basin ecosystem. This document presents responses to the recommendations of the International Joint Commission's (IJC) Tenth Biennial Report on how to improve the performance and effectiveness of government programs such as the Great Lakes Water Quality Agreement. According to the IJC, there are many challenges ahead, including: cleanup of Canadian Areas of Concern; controlling and preventing the further introduction of exotic species; mitigating the impact of rapid urban growth on environmental conditions throughout the basin; and reducing contaminants transported in the atmosphere over long distances to the Great Lakes. This document presented the government's responses to each of the following IJC recommendations regarding remedial action plans, threats to human health with respect to consumption of fish, contaminated sediment, airborne toxic substances, Great Lakes binational toxics strategy, land use, alien invasive species, and information and data management. IJC also recommended that indicators should be reported regarding whether the Great Lakes surface waters are suitable for drinking, swimming and whether fish are edible.

Stakeholder consultations regarding centralized power procurement processes in Ontario

International Nuclear Information System (INIS)

2005-01-01

In 2004, Ontario held 4 Requests for Proposals (RFPs) to encourage the development of new clean renewable combined heat and power generation and the implementation of conservation and demand management programs. Details of a stakeholder consultation related to the RFP process were presented were in this paper. The aim of the consultation was to synthesize stakeholder comments and to provide appropriate recommendations for future RFPs held by the Ontario Power Authority (OPA). The financial burden of bidding was discussed, as well as communications procedures and contract ambiguities. Issues concerning the criteria used for qualifying potential bidders and evaluating project submissions were reviewed. Recommendations for future processes included prequalification, a simplification in collusion requirements, and a fixed time response. It was also recommended that the process should not emphasize financing as lenders do not make firm commitments to bidders prior to a bid being accepted. It was suggested that the amount of bid security should vary with the project size and phase of development, and that the contracts for differences format should be refined to allow participants to propose parameters. Issues concerning audit procedures and performance deviations were reviewed. It was suggested that contract terms should be compatible with gas markets. It was also suggested that the OPA should adopt a more simplified approach to co-generation proposals, where proponents can specify amounts of energy and required prices. The adoption of the Swiss challenge approach of allowing other vendors an opportunity to match or beat terms on an offer was recommended. It was suggested that renewables should be acquired through a targeted and volume limited standard-offer process to be set yearly. Conservation and demand management recommendations were also presented. It was suggested that the OPA should serve as a facilitator of clean development mechanism (CDM) programs. It was

Distribution of Phoxinus eos, Phoxinus neogaeus, and their asexually-reproducing hybrids (Pisces: Cyprinidae in Algonquin Provincial Park, Ontario.

Directory of Open Access Journals (Sweden)

Jonathan A Mee

Full Text Available Hybrid Phoxinus are one of the few asexually reproducing vertebrates species. The distribution of hybrid Phoxinus among lakes in Algonquin Park, Ontario, was evaluated relative to the distribution of parental species and relative to physiochemical lake characteristics. No association between the distribution of hybrids and the distribution of parental species was found, suggesting that the hybrids can successfully coexist with either parental species. In addition, we found no association between hybrid distribution and the physiochemical characteristics of lakes, suggesting that the hybrids are generalists with respect to the ecological niches available in Algonquin Park. There was a difference between the physiochemical characteristics of lakes with and without the parental species P. neogaeus. The lakes containing P. neogaeus were lower elevation than the lakes containing the other parental species, P. eos. The difference in distribution between the parental species may therefore be due to different dispersal abilities, to later arrival following post-glacial dispersal, or to differences in ecology. These results suggest that asexual reproduction is a successful strategy for hybrid Phoxinus in Algonquin Park because these sperm-dependent asexual hybrids are able to survive and persist regardless of which parental species is present, and regardless of the physiochemical characteristics of their habitat.

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

Directory of Open Access Journals (Sweden)

Yury Dvornikov

2018-01-01

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

Holocene lake-level fluctuations of Lake Aricota, Southern Peru

Science.gov (United States)

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

2001-01-01

Lacustrine deposits exposed around Lake Aricota, Peru (17?? 22???S), a 7.5-km2 lake dammed by debris flows, provide a middle to late Holocene record of lake-level fluctuations. Chronological context for shoreline deposits was obtained from radiocarbon dating of vascular plant remains and other datable material with minimal 14C reservoir effects (Titicaca (16?? S), which is only 130 km to the northeast and shares a similar climatology. Comparisons with other marine and terrestrial records highlight emerging contradictions over the nature of mid-Holocene climate in the central Andes. ?? 2001 University of Washington.

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

International Nuclear Information System (INIS)

Morin, K.A.; Cherry, J.A.

1982-01-01

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 226 Ra and 210 Pb. 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 226 Ra, 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 226 Ra, 210 Pb, and uranium are removed from solution by adsorption or coprecipitation

Whole-lake algal responses to a century of acidic industrial deposition on the Canadian Shield

International Nuclear Information System (INIS)

Vinebrooke, R.D.; Dixit, S.S.; Graham, M.D.; Gunn, J.M.; Chen, Y.-W.; Belzile, N.

2002-01-01

A century of cultural acidification is hypothesized to have altered algal community structure in boreal lakes. To date, this hypothesis has remained untested because of both the lack of data predating the onset of industrial pollution and incomplete estimates of whole-lake algal community structure. High-pressure liquid chromatography (HPLC) of sedimentary pigments was used to quantify whole-lake algal responses to acid deposition in six boreal lakes located in Killarney Park, Ontario, Canada. Concomitant significant increases in chlorophyll and carotenoid concentrations, diatom-inferred lake acidity, and metal levels since 1900 suggested that algal abundances in four acidified lakes and one small, circumneutral lake were enhanced by aerial pollution. An alternate explanation is that increased acidity and underwater light availability in the acidified lakes shifted algal abundance towards phytobenthos and deepwater phytoplankton, whose pigment signatures were better preserved in the sediments. Taxonomically diagnostic pigment stratigraphies were consistent with shifts in algal community structure towards filamentous green phytobenthos and deepwater phytoflagellates in the acidified lakes. Our findings suggest that decades of aerial pollution have altered the base of foodwebs in boreal lakes, potentially rendering them less resilient to other environmental stressors. (author)

Influence of lake surface area and total phosphorus on annual bluegill growth in small impoundments of central Georgia

Science.gov (United States)

Jennings, Cecil A.; Sundmark, Aaron P.

2017-01-01

The relationships between environmental variables and the growth rates of fishes are important and rapidly expanding topics in fisheries ecology. We used an informationtheoretic approach to evaluate the influence of lake surface area and total phosphorus on the age-specific growth rates of Lepomis macrochirus (Bluegill) in 6 small impoundments in central Georgia. We used model averaging to create composite models and determine the relative importance of the variables within each model. Results indicated that surface area was the most important factor in the models predicting growth of Bluegills aged 1–4 years; total phosphorus was also an important predictor for the same age-classes. These results suggest that managers can use water quality and lake morphometry variables to create predictive models specific to their waterbody or region to help develop lake-specific management plans that select for and optimize local-level habitat factors for enhancing Bluegill growth.

Implications of the Ontario government's white paper and competition strategies for Ontario's municipal electric utilities

International Nuclear Information System (INIS)

Wills, D.L.

1998-01-01

The strategies that Municipal Electric Utilities (MEU) should follow to deal with competition were discussed. North Bay Hydro is the 34th largest MEU out of 300 in Ontario but it serves only 23,000 out of 4 million electrical customers in Ontario. Therefore, the main strategy for municipal utilities to ensure their future would be to become part of an alliance and association like the MEA and the SAC - the Strategic Alliance for Competition and Customer Choice. Strong criticism was voiced regarding the contents of the recent Ontario Government White Paper for being vague with regard to electrical distribution and the role of MEUs in Ontario. It was suggested that it is vitally important that MEUs ally themselves with other stakeholders, to resist an Ontario Hydro monopoly, to make sure that prices stay low, to avoid excessive debt and bureaucratic inefficiency, be innovative, and consumer oriented and be prepared to anticipate events and conditions. 3 figs

Climate and environmental changes over the past 150 years inferred from the sediments of Chaiwopu Lake, central Tianshan Mountains, northwest China

Science.gov (United States)

Ma, Long; Wu, Jinglu; Abuduwaili, Jilili

2013-04-01

We used a 55-cm sediment core from shallow Chaiwopu Lake in the central Tianshan Mountains of Xinjiang, northwest China, to investigate climate and environmental changes in this arid region over the past ~150 years. The core was dated using 137Cs. We compared temporal changes in several sediment variables with recent meteorological and tree-ring records. Organic matter had a positive correlation with the Palmer Drought Severity Index in the central Tianshan Mountains, and the δ13C of organic matter had a positive correlation with regional temperature. We applied constrained incremental sum-of-squares cluster analysis to element concentrations in the core and identified three distinct zones: (1) 55-46 cm, ~1860-1910, (2) 46-26 cm, ~1910-1952, and (3) 26-0 cm, 1952-present. Between 1880 and 1910 AD, following the Little Ice Age (LIA), the sediment environment was relatively stable, climate was cold and dry, and the lake water displayed high salinity, in contrast to conditions during the LIA. During the LIA, westerlies carried more water vapor into Central Asia when the North Atlantic Oscillation was in a negative phase, and encountered the enhanced Siberia High, which probably led to increased precipitation. In the period 1910-1950 AD, the lake was shallow and the regional climate was unstable, with high temperatures and humidity. In the last ~15-20 years, human activities caused an increase in sediment magnetic susceptibility, and heavy metal and total phosphorus concentrations in the sediment were substantially enriched. Mean annual temperature displays a warming trend over the past 50 years, and the lowest temperature was observed in the 1950s. There has been an increase in annual total precipitation since the 1990s. The combined influences of climate and human activity on the lake environment during this period were faithfully recorded in sediments of Chaiwopu Lake. This study provides a scientific basis for environmental management and protection.

Pacific salmonines in the Great Lakes Basin

Science.gov (United States)

Claramunt, Randall M.; Madenjian, Charles P.; Clapp, David; Taylor, William W.; Lynch, Abigail J.; Léonard, Nancy J.

2012-01-01

Pacific salmon (genus Oncorhynchus) are a valuable resource, both within their native range in the North Pacific rim and in the Great Lakes basin. Understanding their value from a biological and economic perspective in the Great Lakes, however, requires an understanding of changes in the ecosystem and of management actions that have been taken to promote system stability, integrity, and sustainable fisheries. Pacific salmonine introductions to the Great Lakes are comprised mainly of Chinook salmon, coho salmon, and steelhead and have accounted for 421, 177, and 247 million fish, respectively, stocked during 1966-2007. Stocking of Pacific salmonines has been effective in substantially reducing exotic prey fish abundances in several of the Great Lakes (e.g., lakes Michigan, Huron, and Ontario). The goal of our evaluation was to highlight differences in management strategies and perspectives across the basin, and to evaluate policies for Pacific salmonine management in the Great Lakes. Currently, a potential conflict exists between Pacific salmonine management and native fish rehabilitation goals because of the desire to sustain recreational fisheries and to develop self-sustaining populations of stocked Pacific salmonines in the Great Lakes. We provide evidence that suggests Pacific salmonines have not only become naturalized to the food webs of the Great Lakes, but that their populations (specifically Chinook salmon) may be fluctuating in concert with specific prey (i.e., alewives) whose populations are changing relative to environmental conditions and ecosystem disturbances. Remaining questions, however, are whether or not “natural” fluctuations in predator and prey provide enough “stability” in the Great Lakes food webs, and even more importantly, would a choice by managers to attempt to reduce the severity of predator-prey oscillations be antagonistic to native fish restoration efforts. We argue that, on each of the Great Lakes, managers are pursuing

Development of a spatial forest data base for the eastern boreal forest region of Ontario. Forest fragmentation and biodiversity project technical report No. 14

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-12-31

In 1991, a spatial forest database over large regions of Ontario was initiated as the basis for research into forest fragmentation and biodiversity using data generated from the digital analysis of LANDSAT thematic mapper satellite data integrated into a geographic information system (GIS). The project was later extended into the eastern segment of the Boreal forest system. This report describes preparation of the spatial forest data base over the eastern Boreal Forest Region that extends from the northern boundary of the Great Lakes-St. Lawrence Forest Region and the southern margin of the James Bay Lowland, between the Ontario-Quebec border and a point west of Michipicoten on Lake Superior. The report describes the methodology used to produce the data base and results, including mapping of water, dense and sparse conifer forest, mixed forest, dense and sparse deciduous forest, poorly vegetated areas, recent cutovers of less than 10 years, old cutovers and burns, recent burns of less than 10 years, wetlands, bedrock outcrops, agriculture, built-up areas, and mine tailings.

New data on mitochondrial diversity and origin of Hemimysis anomala in the Laurentian Great Lakes

Science.gov (United States)

Questel, Jennifer M.; Walsh, Maureen G.; Smith, Randall J.; Welsh, Amy B.

2012-01-01

The most recent Ponto-Caspian species to invade the Laurentian Great Lakes is the crustacean Hemimysis anomala, first reported in 2006. A previous study described three haplotype groups (A, B, C) of H. anomala in native and invaded areas within Europe, but only one haplotype (A1) in a sample from Lake Michigan. Our study expands these results to additional populations in the Great Lakes basin, and evaluates relationships among North American and European populations. A 549-bp fragment of themitochondrial cytochrome oxidase I (COI) gene was analyzed from populations of H. anomala in Lakes Ontario, Erie, Huron, and the St. Lawrence River.Two different haplotypes, A1 and B1,were observed in the sampled populations of H. anomala and in a previous analysis from H. anomala in Oneida Lake (New York). Our results, in contrast with a previous study, detect an additional haplotype in North America.

Trading our health: Ontario Power Generation's plan to violate its air pollution reduction commitment

International Nuclear Information System (INIS)

Gibbons, J.; Bjorkquist, S.

1999-01-01

Amid growing concerns about nitrogen oxide (Nox) emissions, the Ontario Clean Air Alliance is recommending in this report that the Ontario government restrict Nox emissions from Ontario Power Generation (OPG) in the year 2000 and not let the corporation meet its emissions cap by on a net basis by retiring Pilot Emission Reduction Trading (PERT) Nox emission reduction credits. Instead the alliance believes the Ontario government should require OPG to achieve emissions compliance by curtailing coal-fired electricity exports, purchasing renewable and natural-gas electricity and promoting energy efficiency. OPG's inventory of PERT Nox reduction credits are assessed against whether they will cause an increase in the year 2000 as a result of trading. Ontario Power Generation's Nox emissions are a central chemical component of acid rain and smog and are produced from its coal-fired electricity generators. The utility would like to achieve Nox reductions by establishing demand management programs which would reduce the demand for electricity by 5200 megawatts (MW), by purchasing 3100 MW of non-utility generation and by undertaking combustion process modifications at its Lambton and Nanticoke coal-fired generating stations. It has not met its 2000 demand management and non-utility generation targets, and specifically, as of December 31, 1998, Ontario Hydro's successor companies demand management programs have only reduced electricity demand by approximately 1300 MW. Furthermore, the successor companies will have only approximately 1700 MW of non-utility generation capacity under contract by December 31, 1999. The report describes the criteria for ensuring that Nox emissions trading will not lead to a net increase in Ontario's emissions in any given year, and a description is included of why the 'Draft Rules for Emission Trading in Ontario' rules do not meet these criteria. Permitting OPG to use its PERT credits to meet its Nox cap, will allow them to increase coal

Dreissenid mussels from the Great Lakes contain elevated thiaminase activity

Science.gov (United States)

Tillitt, D.E.; Riley, S.C.; Evans, A.N.; Nichols, S.J.; Zajicek, J.L.; Rinchard, J.; Richter, C.A.; Krueger, C.C.

2009-01-01

We examined thiaminase activity in dreissenid mussels collected at different depths and seasons, and from various locations in Lakes Michigan, Ontario, and Huron. Here we present evidence that two dreissenid mussel species (Dreissena bugensis and D. polymorpha) contain thiaminase activity that is 5-100 fold greater than observed in Great Lakes fishes. Thiaminase activity in zebra mussels ranged from 10,600 to 47,900??pmol g- 1??min- 1 and activities in quagga mussels ranged from 19,500 to 223,800??pmol g- 1??min- 1. Activity in the mussels was greatest in spring, less in summer, and least in fall. Additionally, we observed greater thiaminase activity in dreissenid mussels collected at shallow depths compared to mussels collected at deeper depths. Dreissenids constitute a significant and previously unknown pool of thiaminase in the Great Lakes food web compared to other known sources of this thiamine (vitamin B1)-degrading enzyme. Thiaminase in forage fish of the Great Lakes has been causally linked to thiamine deficiency in salmonines. We currently do not know whether linkages exist between thiaminase activities observed in dreissenids and the thiaminase activities in higher trophic levels of the Great Lakes food web. However, the extreme thiaminase activities observed in dreissenids from the Great Lakes may represent a serious unanticipated negative effect of these exotic species on Great Lakes ecosystems.

Spatial and seasonal contrasts of sedimentary organic matter in floodplain lakes of the central Amazon basin

OpenAIRE

Sobrinho, R. L.; Bernardes, M. C.; Abril, G.; Kim, J. H.; Zell, C. I.; Mortillaro, J. M.; Meziane, T.; Moreira Turcq, Patricia; Damste, J. S. S.

2016-01-01

In this study, we investigated the seasonal and spatial pattern of sedimentary organic matter (SOM) in five floodplain lakes of the central Amazon basin (Cabaliana, Janauaca, Canaçari, Miratuba, and Curuai) which have different morphologies, hydrodynamics and vegetation coverages. Surface sediments were collected in four hydrological seasons: low water (LW), rising water (RW), high water (HW) and falling water (FW) in 2009 and 2010. We investigated commonly used bulk geochem...

PARENTAL CONSUMPTION OF CONTAMINATED SPORT FISH FROM LAKE ONTARIO AND PREDICTED FECUNDABILITY

Science.gov (United States)

Wildlife studies suggest that consumption of contaminated fish from the Great Lakes may expose humans to polychlorinated biphenyls and persistent chlorinated pesticides. To assess whether time to pregnancy or fecundability is affected, we conducted a telephone survey in 1993 with...

Geochemical pathways and biological uptake of radium in small Canadian Shield lakes

International Nuclear Information System (INIS)

Hesslein, R.H.; Slavicek, E.

1984-01-01

The sediment-water interactions and biological uptake of 226 Ra are described for four small Canadian Shield lakes at the Experimental Lakes Area, Kenora, Ontario. A single addition of 226 Ra was made to each lake between 1970 and 1976. Approximately 90 percent of the added 226 Ra initially sorbed to the sediments. Outflow from the lakes showed losses of only 5-11 percent 226 Ra per year. Models are proposed for adsorption and outflow of 226 Ra from lakes. Biological uptake and long-term 226 Ra concentrations were measured in three species of macrophytes, crayfish, and five species of fish. Bioaccumulation ranged from 1100 to 5000 in macrophytes, 705 in crayfish, from 30 to 80 in large trout (Salvelinus namaycush), white sucker (Catostomus commersoni), and lake whitefish (Coregonus clupeaformis), and from 230 to 1200 in fathead minnows (Pimephales promelas), pearl dace (Semotilus margarita), and northern redbelly dace (Chrosomus eos). The concept of Ra/Ca ratio in organisms versus water and food is used to explain the differences in bioaccumulation. 226 Ra is discriminated against versus calcium by fish but favoured by macrophytes and crayfish

Occurrence of chlorinated paraffins in beluga whales (Delphinapterus leucas) from the St. Lawrence River and rainbow trout (Oncorhynchus mykiss) and carp (Cyprinus carpio) from Lake Ontario

Energy Technology Data Exchange (ETDEWEB)

Bennie, D. T.; Sullivan, C. A.; Maguire, R. J. [Envirronment Canada, National Water Research Institute, Burlington, ON (Canada)

2000-07-01

Samples of 25 dead beluga whales from the St. Lawrence River estuary, as well as samples of 10 rainbow trout and three carps caught in western Lake Ontario were analyzed for total short and medium chain chlorinated paraffins using gas chromatography-low resolution negative chemical ionization spectroscopy. Both short and medium-chain chlorinated paraffins were quantitatively identified in all samples using two commercial preparations. Beluga results were found to be higher than concentrations reported for marine mammals in Europe, but comparable to total PCB and total DDT results for the same population of beluga whales. Results for freshwater species are comparable to those reported for fish sampled from other industrially impacted waterways in North America, but elevated compared to marine species from European studies. Comparisons of the results with gas chromatography-negative ion mass spectroscopy analysis from another study indicated that the two analytical techniques are not congruent. The differences may be accounted for by different effects of interfering organochlorine substances on the analysis of chlorinated paraffins. 22 refs., 5 tabs., 1 fig.

Ontario perspective on interregional markets

International Nuclear Information System (INIS)

Shalaby, A.

2003-01-01

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

Ontario's power market post November 11

International Nuclear Information System (INIS)

Murphy, P.

2003-01-01

This paper provides a review of Ontario's first year with an open electricity market. The year 2002 to 2003 had record energy demands with challenges on the supply side. In particular, generation availability was below expectations during the summer months. This demonstrated that price predictability and volatility needs to be addressed and investment in new power generation is needed in Ontario. Ontario demand forecasts outpace supply for the long term outlook. In addition, most of Ontario's generating plants are aging and will soon exceed their nominal service life, requiring major refurbishment or replacement. Decisions are needed now on the future of coal in Ontario's generation mix. It was also noted that transmission reinforcements are needed in the Greater Toronto Area (GTA). In the short term, consumers can expect delays in return to service of nuclear units, forced extensions to planned outages, and reduced outlook for energy from hydroelectric resources. It was noted that Ontario will continue to rely on imports, although emergency generation is being installed. 5 figs

Centrarchid fish as paratenic hosts of the giant kidney worm, Dioctophyma renale (Goeze, 1782), in Ontario, Canada.

Science.gov (United States)

Measures, L N; Anderson, R C

1985-01-01

Infective larvae of Dioctophyma renale were found in the hypaxial musculature of pumpkinseed (Lepomis gibbosus L.) from three lakes in Algonquin Provincial Park, Ontario, Canada. This represents the first report of D. renale in centrarchid fish. In the three lakes surveyed prevalence and mean intensity ranged from 5 to 23% and one to two larvae respectively. Larvae elicited a mild granulomatous reaction in pumpkinseed. Two ferrets were each given five larvae from pumpkinseed. Adult D. renale were recovered from the right kidney capsule of ferrets 108 and 134 days post-infection. An opening in the ventral surface of the right kidney capsule was present in one ferret. Chronic peritonitis was associated with eggs of D. renale and cellular debris which probably entered the abdominal cavity from the right kidney capsule.

Ontario Energy Corporation annual report 1981. [Monograph

Energy Technology Data Exchange (ETDEWEB)

1981-01-01

The Ontario Energy Corporation's mission of providing leadership and investment capital for selected energy ventures brought its total participation in projects from $16.4 million to $669 million, and its total assets increased from $44.4 million to $693 million during the year. The annual report review major operations with Ontario Energy Resources Ltd., Onexco Ltd., Ontario Alternate Energy Ltd., Ontario Power Share Ltd., and Ontario Energy in Transportation Ltd. The financial report includes a balance sheet, income and retained earnings statement, and a summary of financial changes during the reporting period. 1 figure, 4 tables. (DCK)

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...

New age constraints for the Saalian glaciation in northern central Europe: Implications for the extent of ice sheets and related proglacial lake systems

Science.gov (United States)

Lang, Jörg; Lauer, Tobias; Winsemann, Jutta

2018-01-01

A comprehensive palaeogeographic reconstruction of ice sheets and related proglacial lake systems for the older Saalian glaciation in northern central Europe is presented, which is based on the integration of palaeo-ice flow data, till provenance, facies analysis, geomorphology and new luminescence ages of ice-marginal deposits. Three major ice advances with different ice-advance directions and source areas are indicated by palaeo-ice flow directions and till provenance. The first ice advance was characterised by a southwards directed ice flow and a dominance of clasts derived from southern Sweden. The second ice advance was initially characterised by an ice flow towards the southwest. Clasts are mainly derived from southern and central Sweden. The latest stage in the study area (third ice advance) was characterised by ice streaming (Hondsrug ice stream) in the west and a re-advance in the east. Clasts of this stage are mainly derived from eastern Fennoscandia. Numerical ages for the first ice advance are sparse, but may indicate a correlation with MIS 8 or early MIS 6. New pIRIR290 luminescence ages of ice-marginal deposits attributed to the second ice advance range from 175 ± 10 to 156 ± 24 ka and correlate with MIS 6. The ice sheets repeatedly blocked the main river-drainage pathways and led to the formation of extensive ice-dammed lakes. The formation of proglacial lakes was mainly controlled by ice-damming of river valleys and major bedrock spillways; therefore the lake levels and extends were very similar throughout the repeated ice advances. During deglaciation the lakes commonly increased in size and eventually drained successively towards the west and northwest into the Lower Rhine Embayment and the North Sea. Catastrophic lake-drainage events occurred when large overspill channels were suddenly opened. Ice-streaming at the end of the older Saalian glaciation was probably triggered by major lake-drainage events.

Translating Research into Practice: Establishing a Network of Climate Change Practitioners in Ontario, Canada

Science.gov (United States)

Milner, G. A.

2017-12-01

Climate research and information continues to emerge at a rapid pace from the academic and scientific community. Decisions being made today by planners, engineers and staff across the Province of Ontario rely on science and information to plan and build our systems for the long term. Of course, as scientific information evolves continuously to produce lessons learned and new evidence, on the ground decisions often become entrenched in outdated information and need updating. Given this, bridging the gap between research to policy, and research to practice is of critical importance as the Province of Ontario upgrades its infrastructure, plans for long term growth in population within the Great Lakes Basin, and manages its natural systems and resources responsibly. The Ontario Climate Consortium (OCC) is an interdisciplinary network of academics and practitioners established in 2011 in the province that works to mobilize climate research findings towards building capacity, inspiring climate action, and training end-users with the latest science. The OCC has collaborated with more than 39 organizations throughout Ontario and across Canada, including government agencies at all levels (local, provincial and federal), non-profit organizations and private sector companies. This presentation will describe the foundations of climate action in Ontario, Canada including the landscape of climate adaptation practitioners from both public and private organizations. Furthermore, this presentation will feature lessons learned from the OCC network, including: 1) What comprises effective partnerships to undertake climate change adaptation planning for cities; 2) How to build the foundation for capacity at agencies with limited resources or expertise in the climate change field; and 3) How to successfully mobilize complex climate data for end-users to produce usable tools (through a case study research project). The latter will present findings from a two-year research project

Little Galloo Island, Lake Ontario: A review of nine years of double-crested cormorant diet and fish consumption information

Science.gov (United States)

Johnson, James H.; Ross, Robert M.; McCullough, Russ D.

2002-01-01

The diet of double-crested cormorants (Phalacrocorax auritus) on Little Galloo Island (LGI) in the eastern basin of Lake Ontario has been quantified since 1992. Over the past nine years considerable information has been generated on cormorant feeding ecology through the examination of approximately 12,000 pellets collected on LGI, where three distinct cormorant feeding periods, pre-chick, chick, and post-chick, are delineated by differences in diet composition and daily fish consumption. Yellow perch (Perca flavescens) were the major prey during pre-chick and post-chick feeding periods. Alewife (Alosa pseudoharengus), which move inshore to spawn in mid-June, dominated (>60%) cormorant diets during the chick feeding period. Mean daily fish consumption (14.6) during the pre-chick feeding period was significantly greater than during the chick feeding (9.3) or post-chick feeding (8.0) periods. The proportion of smallmouth bass (Micropterus dolomieu) in the diet increased over the season (0.8% to 7.2%), while the size of bass consumed declined (214 mm to 143 mm). Forage fish (mainly alewife, three-spine sticklebacks [Gasterosteus aculeatus] and minnows) comprised 58% of the diet of LGI cormorants, followed by panfish (37%) (yellow perch, pumpkinseed [Lepomis gibbosus], rock bass [Ambloplites rupestris]) and gamefish (5%) (mostly smallmouth bass). On the average LGI cormorants consumed about 32.8 million fish annually, weighing about 1.4 million kilograms. Cormorants from LGI consumed more biomass of smallmouth bass and yellow perch annually than is taken by sport (bass and yellow perch) and commercial (perch) fishermen.

Distribution of acidic and neutral drugs in surface waters near sewage treatment plants in the lower Great Lakes, Canada.

Science.gov (United States)

Metcalfe, Chris D; Miao, Xiu-Sheng; Koenig, Brenda G; Struger, John

2003-12-01

Prescription and nonprescription drugs have been detected in rivers and streams in Europe and the United States. Sewage treatment plants (STPs) are an important source of these contaminants, but few data exist on the spatial distribution of drugs in surface waters near STPs. Samples of surface water were collected in the summer and fall of 2000 at open-water sites in the lower Great Lakes (Lake Ontario and Lake Erie), at sites near the two STPs for the city of Windsor (ON, Canada), and at sites in Hamilton Harbour (ON, Canada), an embayment of western Lake Ontario that receives discharges from several STPs. In a follow-up study in the summer of 2002, samples of surface water and final effluent from adjacent STPs were collected from sites in Hamilton Harbour and Windsor. In addition, surface water and STP effluent samples were collected in Peterborough (ON, Canada). All samples of surface water and STP effluents were analyzed for selected acidic and neutral drugs. In the survey of Hamilton Harbour and Windsor conducted in 2000, acidic drugs and the antiepileptic drug carbamazepine were detected at ng/L concentrations at sites that were up to 500 m away from the STP, but the hydrological conditions of the receiving waters strongly influenced the spatial distribution of these compounds. Drugs were not detected at open-water locations in western Lake Erie or in the Niagara River near the municipality of Niagara-on-the-Lake (ON, Canada). However, clofibric acid, ketoprofen, fenoprofen, and carbamazepine were detected in samples collected in the summer of 2000 at sites in Lake Ontario and at a site in the Niagara River (Fort Erie, ON, Canada) that were relatively remote from STP discharges. Follow-up studies in the summer of 2002 indicated that concentrations of acidic and neutral drugs in surface waters near the point of sewage discharge into the Little River (ON, Canada) STP were approximately equal to the concentrations in the final effluent from the STP. Caffeine and

The hydrological and environmental evolution of shallow Lake Melincué, central Argentinean Pampas, during the last millennium

Science.gov (United States)

Guerra, Lucía; Piovano, Eduardo L.; Córdoba, Francisco E.; Sylvestre, Florence; Damatto, Sandra

2015-10-01

Lake Melincué, located in the central Pampean Plains of Argentina, is a shallow (∼4 m), subsaline lake (TDS > 2000 ppm), highly sensitive to hydrological changes. The modern shallow lake system is composed of: (a) a supralittoral area, which includes a narrow mudflat, a vegetated mudflat and wetlands subenvironments; and (b) the main water body, comprising lacustrine marginal and inner areas. The development and extension of these subenvironments are strongly conditioned upon lake surface fluctuations. Past environmental changes were reconstructed through sedimentological, physical and geochemical proxy analyses of two short sedimentary cores (∼127 cm). Well-constrained 210Pb ages profiles were modeled and radiocarbon chronologies were determined, covering a period from ∼AD 800 to the present. The analyzed sedimentary cores from Lake Melincué allowed for the reconstruction of past hydrological scenarios and associated environmental variability, ranging from extremely low lake levels during dry phases to pronounced highstands at wet periods. The paleohydrological reconstruction revealed very shallow conditions in the period between AD 806 and AD 1880, which was registered by massive deposits with low organic matter. Relatively wetter phases disrupting this dry period were represented by organic matter increases. A major wet phase was registered by AD 1454, after the end of the Medieval Climate Anomaly. A subsequent abrupt shift from this wet phase to drier conditions could be matching the transition between the end of the Medieval Climatic Anomaly and the beginning of the Little Ice Age. The occurrence of sedimentary hiatuses between AD 1492 and AD 1880 in Melincué sequence could correspond to intensive droughts during the Little Ice Age. After AD 1880, banded and laminated, autochthonous, organic matter-rich sediments registered an important lacustrine transgression and the onset of a permanent shallow lake, corresponding to the beginning of the current

Sources of anthropogenic lead in sediments from an artificial lake in Brasilia-central Brazil

International Nuclear Information System (INIS)

Gioia, S.M.C.L.; Pimentel, M.M.; Tessler, M.; Dantas, E.L.; Campos, J.E.G.; Guimaraes, E.M.; Maruoka, M.T.S.; Nascimento, E.L.C.

2006-01-01

Pb concentration and Pb isotopic composition are known to represent powerful tools to investigate the history of Pb pollution in water and sediments. In this paper, we present and discuss the results of a detailed study of sediments deposited in the Paranoa Lake, a 44-year-old artificial reservoir in Brasilia, central Brazil. Pb concentration and isotopic composition of the sediments were obtained by ID-TIMS, on three different sample fractions: leachate, residue, and bulk sample. The leachate phase has proven to be most efficient to distinguish between anthropogenic and natural Pb inputs. In the Paranoa lake, important sources of contamination were recognized, producing higher Pb concentrations (max. 37.68 ppm) and significant variations in Pb isotopic composition, relative to the regional geogenic background. Contamination of the sediments due to anthropogenic activity produced less radiogenic Pb isotopic compositions ( 206 Pb/ 207 Pb = 1.15-1.17), compared with the regional natural composition ( 206 Pb/ 207 Pb = 1.19-1.25). 21 Pb analyses along one bore hole which sampled the entire sediment section indicated a sedimentation rate of 8.2 ± 1.8 mm/year. The combined use of the 21 Pb ages and Pb isotopic compositions of these samples revealed three distinct periods in the lake history: (1) the period of the time formation of the lake in 1959 until ca. 1970 was characterized by the deposition of sediments displaying more radiogenic Pb isotopic signature, (2) the time interval from the start of the process of eutrophication at 1970, until 1995, was characterized by the deposition of sediments having less radiogenic average compositions, and (3) from 1995 until the present represents a period of recovery of water quality, after two sewage treatment stations started to operate

Ontario feed-in-tariff programs

International Nuclear Information System (INIS)

Yatchew, Adonis; Baziliauskas, Andy

2011-01-01

Recent feed-in-tariff (FIT) programs in Ontario, Canada have elicited a very strong supply response. Within the first year of their inception, the Ontario Power Authority received applications totaling over 15,000 MW, equivalent to about 43% of current Ontario electricity generating capacity. The overwhelming share of applications is for wind-power (69%) and solar photovoltaic (28%) generating facilities. Wind generation is being remunerated at 14-19 cents /kWh. Solar facilities receive from 40 to 80 cents /kWh. The initiative, which responds to Provincial legislation is administratively divided into applications for facilities exceeding 10 kW (the FIT program) and those less than or equal to 10 kW (the microFIT program). This paper describes the programs and their features, compares them to their predecessors in Ontario as well as to programs elsewhere, analyses the reasons for the very strong response, and assesses their efficacy and sustainability. - Research highlights: → Recent feed-in-tariff (FIT) programs in Ontario, Canada have elicited a very strong supply response. Within the first year, applications totaled over 15,000 MW, equivalent to about 43% of current Ontario electricity generating capacity. → Most projects are either solar or wind. → Likely causes of strong supply response-preferred system access and favorable, secure tariffs. (Wind generation is being remunerated at 14-19 cents /kWh. Solar facilities receive from 40 to 80 cents /kWh.) → Long term political sustainability of present program is in question.

Artificial reefs and reef restoration in the Laurentian Great Lakes

Science.gov (United States)

McLean, Matthew W.; Roseman, Edward; Pritt, Jeremy J.; Kennedy, Gregory W.; Manny, Bruce A.

2015-01-01

We reviewed the published literature to provide an inventory of Laurentian Great Lakes artificial reef projects and their purposes. We also sought to characterize physical and biological monitoring for artificial reef projects in the Great Lakes and determine the success of artificial reefs in meeting project objectives. We found records of 6 artificial reefs in Lake Erie, 8 in Lake Michigan, 3 in Lakes Huron and Ontario, and 2 in Lake Superior. We found 9 reefs in Great Lakes connecting channels and 6 reefs in Great Lakes tributaries. Objectives of artificial reef creation have included reducing impacts of currents and waves, providing safe harbors, improving sport-fishing opportunities, and enhancing/restoring fish spawning habitats. Most reefs in the lakes themselves were incidental (not created purposely for fish habitat) or built to improve local sport fishing, whereas reefs in tributaries and connecting channels were more frequently built to benefit fish spawning. Levels of assessment of reef performance varied; but long-term monitoring was uncommon as was assessment of physical attributes. Artificial reefs were often successful at attracting recreational species and spawning fish; however, population-level benefits of artificial reefs are unclear. Stressors such as sedimentation and bio-fouling can limit the effectiveness of artificial reefs as spawning enhancement tools. Our investigation underscores the need to develop standard protocols for monitoring the biological and physical attributes of artificial structures. Further, long-term monitoring is needed to assess the benefits of artificial reefs to fish populations and inform future artificial reef projects.

[Ontario Hydro]. Corporate performance report, 1993

International Nuclear Information System (INIS)

1994-01-01

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

Expansion of the uranium mines in the Elliot Lake area

International Nuclear Information System (INIS)

1979-11-01

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.)

Heat balance in main lakes of central Italy; Bilancio termico dei principali laghi dell`Italia Centrale

Energy Technology Data Exchange (ETDEWEB)

Monte, L.; Baldini, E.; Battella, C.; Fratarcangeli, S.; Pompei, F. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dip. Ambiente

1996-07-01

A thermodynamic model for predicting the thermal stratification of water of deep lakes and the components of the heat balance of lacustrine systems was developed in the frame of the researches on predictive limnology. The model has been applied to Bracciano, Bolsena and Trasimeno lakes. The validation of the temperature results demonstrated the reliability of the model and, as consequence, of the thermal balances of the lakes. The calculated yearly evaporation is about 800 mm.

Glacial lake inventory and lake outburst potential in Uzbekistan.

Science.gov (United States)

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

2017-08-15

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

Do invasive quagga mussels alter CO2 dynamics in the Laurentian Great Lakes?

Science.gov (United States)

Lin, Peng; Guo, Laodong

2016-12-01

The Laurentian Great Lakes have experienced unprecedented ecological and environmental changes, especially after the introduction of invasive quagga mussel (Dreissena rostriformis bugensis). While impacts on ecological functions have been widely recognized, the response of carbon dynamics to invasive species remains largely unknown. We report new CO2 data showing significant increases in pCO2 (up to 800 μatm in Lake Michigan) and CO2 emission fluxes in most of the Great Lakes compared to those prior to or during the early stage of the colonization of invasive quagga mussels. The increased CO2 supersaturation is most prominent in Lakes Huron and Michigan, followed by Lakes Ontario and Erie, but no evident change was observed in Lake Superior. This trend mirrors the infestation extent of invasive quagga mussels in the Great Lakes and is consistent with the decline in primary production and increase in water clarity observed pre- and post-Dreissena introduction, revealing a close linkage between invasive species and carbon dynamics. The Great Lakes have become a significant CO2 source to the atmosphere, emitting >7.7 ± 1.0 Tg-C annually, which is higher than the organic carbon burial rate in global inland-seas and attesting to the significant role of the Laurentian Great Lakes in regional/global CO2 budget and cycling.

The safety of Ontario's nuclear reactors

International Nuclear Information System (INIS)

1980-06-01

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.)

Glacier Change, Supraglacial Debris Expansion and Glacial Lake Evolution in the Gyirong River Basin, Central Himalayas, between 1988 and 2015

Directory of Open Access Journals (Sweden)

Sheng Jiang

2018-06-01

Full Text Available Himalayan glacier changes in the context of global climate change have attracted worldwide attention due to their profound cryo-hydrological ramifications. However, an integrated understanding of the debris-free and debris-covered glacier evolution and its interaction with glacial lake is still lacking. Using one case study in the Gyirong River Basin located in the central Himalayas, this paper applied archival Landsat imagery and an automated mapping method to understand how glaciers and glacial lakes interactively evolved between 1988 and 2015. Our analyses identified 467 glaciers in 1988, containing 435 debris-free and 32 debris-covered glaciers, with a total area of 614.09 ± 36.69 km2. These glaciers decreased by 16.45% in area from 1988 to 2015, with an accelerated retreat rate after 1994. Debris-free glaciers retreated faster than debris-covered glaciers. As a result of glacial downwasting, supraglacial debris coverage expanded upward by 17.79 km2 (24.44%. Concurrent with glacial retreat, glacial lakes increased in both number (+41 and area (+54.11%. Glacier-connected lakes likely accelerated the glacial retreat via thermal energy transmission and contributed to over 15% of the area loss in their connected glaciers. On the other hand, significant glacial retreats led to disconnections from their proglacial lakes, which appeared to stabilize the lake areas. Continuous expansions in the lakes connected with debris-covered glaciers, therefore, need additional attention due to their potential outbursts. In comparison with precipitation variation, temperature increase was the primary driver of such glacier and glacial lake changes. In addition, debris coverage, size, altitude, and connectivity with glacial lakes also affected the degree of glacial changes and resulted in the spatial heterogeneity of glacial wastage across the Gyirong River Basin.

Renewables without limits : moving Ontario to advanced renewable tariffs by updating Ontario's groundbreaking standard offer program

International Nuclear Information System (INIS)

Gipe, P.

2007-11-01

The Ontario Sustainable Energy Association (OSEA) promotes the development of community-owned renewable energy generation. It was emphasized that in order to achieve OSEA's original objectives of developing as much renewable energy as quickly as possible through community participation, changes are needed to Ontario's groundbreaking standard offer contract (SOC) program. This report examined the status of Ontario's SOC program and proposed changes to the program as part of the program's first two-year review. The report provided a summary of the program and discussed each of the program's goals, notably to encourage broad participation; eliminate barriers to distributed renewable generation; provide a stable market for renewable generation; stimulate new investment in renewable generation; provide a rigorous pricing model for setting the tariffs; create a program applicable to all renewable technologies; provide a simple, streamlined, and cost-effective application process; and provide a dispute resolution process. The program goals as developed by the Ontario Power Authority and Ontario Energy Board were discussed with reference to mixed results to date; simplicity; removing barriers; balancing targets with value to ratepayers; and building on the efforts of OSEA. Advanced renewable tariffs (ART) and tariff determination was also discussed along with ART's in Germany, France, Spain and Ontario. Inflation indexing; tariff degression; proposed new tariffs by technology; and other costs and factors affecting profitability were also reviewed. ref., tabs

Cogeneration markets in Ontario

International Nuclear Information System (INIS)

Poredos, S.

1993-01-01

Cogeneration offers a key strategy which supports global competitiveness for Ontario businesses, encourages energy efficiency and environmental protection, and offers natural gas utilities and producers stable long-term incremental markets. By supporting cogeneration projects, electric utilities will benefit from increased flexibility. Natural gas is the fuel of choice for cogeneration, which can in most cases be easily integrated into existing operations. In Ontario, electric demand grew along with the gross domestic product until 1990, but has decreased with the recent economic recession. The provincial utility Ontario Hydro is resizing itself to stabilize total rate increases of 30% over the last three years and supporting reduction of its high debt load. Rate increases are supposed to be limited but this may be difficult to achieve without further cost-cutting measures. Cogeneration opportunities exist with many institutional and industrial customers who are trying to remain globally competitive by cutting operating costs. In general, cogeneration can save 20% or more of total annual energy costs. Due to excess capacity, Ontario Hydro is not willing to purchase electric power, thus only electric load displacement projects are valid at this time. This will reduce overall savings due to economies of scale. In southwestern Ontario, Union Gas Ltd. has been successful in developing 40 MW of electric displacement projects, providing a total load of 5 billion ft 3 of natural gas (50% of which is incremental). Over 3,000 MW of technical cogeneration potential is estimated to exist in the Union Gas franchise area

Differences in the water-balance components of four lakes in the southern-central Tibetan Plateau

Science.gov (United States)

Biskop, S.; Maussion, F.; Krause, P.; Fink, M.

2016-01-01

The contrasting patterns of lake-level fluctuations across the Tibetan Plateau (TP) are indicators of differences in the water balance over the TP. However, little is known about the key hydrological factors controlling this variability. The purpose of this study is to contribute to a more quantitative understanding of these factors for four selected lakes in the southern-central part of the TP: Nam Co and Tangra Yumco (increasing water levels), and Mapam Yumco and Paiku Co (stable or slightly decreasing water levels). We present the results of an integrated approach combining hydrological modeling, atmospheric-model output and remote-sensing data. The J2000g hydrological model was adapted and extended according to the specific characteristics of closed-lake basins on the TP and driven with High Asia Refined analysis (HAR) data at 10 km resolution for the period 2001-2010. Differences in the mean annual water balances among the four basins are primarily related to higher precipitation totals and attributed runoff generation in the Nam Co and Tangra Yumco basins. Precipitation and associated runoff are the main driving forces for inter-annual lake variations. The glacier-meltwater contribution to the total basin runoff volume (between 14 and 30 % averaged over the 10-year period) plays a less important role compared to runoff generation from rainfall and snowmelt in non-glacierized land areas. Nevertheless, using a hypothetical ice-free scenario in the hydrological model, we indicate that ice-melt water constitutes an important water-supply component for Mapam Yumco and Paiku Co, in order to maintain a state close to equilibrium, whereas the water balance in the Nam Co and Tangra Yumco basins remains positive under ice-free conditions. These results highlight the benefits of linking hydrological modeling with atmospheric-model output and satellite-derived data, and the presented approach can be readily transferred to other data-scarce closed lake basins, opening new

Transmission solutions : a 10 year plan for the province of Ontario 2005-2014

International Nuclear Information System (INIS)

2005-02-01

This paper present a 10 year transmission plan for Ontario by Hydro One Networks Inc., the largest electricity delivery company in the province. A history of Hydro One Network's activities during the past century was provided as well as information about the company and details of their mission and objectives. A list of their accomplishments during 2004 was also presented. An outline of the current transmission infrastructure system was presented. Elements of the plan include customer connections; area supply reliability; facilitation of electricity supply; and transmission needs and solutions. Plans specific to central, western, eastern and northeastern zones were also presented, including zone maps of transmission lines and generating stations. Changes included: Bill 100, the Electricity Restructuring Act in 2004 and the establishment of the Ontario Power Authority (OPA); changes to the Ontario Energy Board's Transmission System Code (TSC); government measures to increase the supply of electricity through requests for proposals (RFPs) for new renewable and clean energy; and the announcement of an increase in the amount of wind energy through the Wind Power Production Incentive program. refs., tabs., figs

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

Science.gov (United States)

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

2014-05-13

Some of the most pivotal questions in human history necessitate the investigation of archaeological sites that are now under water. Nine thousand years ago, the Alpena-Amberley Ridge (AAR) beneath modern Lake Huron was a dry land corridor that connected northeast Michigan to southern Ontario. The newly discovered Drop 45 Drive Lane is the most complex hunting structure found to date beneath the Great Lakes. The site and its associated artifacts provide unprecedented insight into the social and seasonal organization of prehistoric caribou hunting. When combined with environmental and simulation studies, it is suggested that distinctly different seasonal strategies were used by early hunters on the AAR, with autumn hunting being carried out by small groups, and spring hunts being conducted by larger groups of cooperating hunters.

Alternative models for restructuring Ontario's electric sector

International Nuclear Information System (INIS)

Bright, D.; Salaff, S.

1996-01-01

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

Paleoenvironments, Evolution, and Geomicrobiology in a Tropical Pacific Lake: The Lake Towuti Drilling Project (TOWUTI)

Science.gov (United States)

Vogel, Hendrik; Russell, James M.; Bijaksana, Satria; Crowe, Sean; Fowle, David; Haffner, Douglas; King, John; Marwoto, Ristiyanti; Melles, Martin; von Rintelen, Thomas; Stevenson, Janelle; Watkinson, Ian; Wattrus, Nigel

2014-05-01

Lake Towuti (2.5°S, 121°E) is a, 560 km2, 200-m deep tectonic lake at the downstream end of the Malili lake system, a set of five, ancient (1-2 MYr) tectonic lakes in central Sulawesi, Indonesia. Lake Towuti's location in central Indonesia provides a unique opportunity to reconstruct long-term paleoclimate change in a crucially important yet understudied region- the Indo-Pacific warm pool (IPWP), heart of the El Niño-Southern Oscillation. The Malili Lakes have extraordinarily high rates of floral and faunal endemism, and the lakes are surrounded by one of the most diverse tropical forests on Earth. Drilling in Lake Towuti will identify the age and origin of the lake and the environmental and climatic context that shaped the evolution of this unique lacustrine and terrestrial ecosystem. The ultramafic (ophiolitic) rocks and lateritic soils surrounding Lake Towuti provide metal substrates that feed a diverse, exotic microbial community, analogous to the microbial ecosystems that operated in the Archean Oceans. Drill core will provide unique insight into long-term changes in this ecosystem, as well as microbial processes operating at depth in the sediment column. High-resolution seismic reflection data (CHIRP and airgun) combined with numerous long sediment piston cores collected from 2007-2013 demonstrate the enormous promise of Lake Towuti for an ICDP drilling campaign. Well-stratified sequences of up to 150 m thickness, uninterrupted by unconformities or erosional truncation, are present in multiple sub-basins within Towuti, providing ideal sites for long-term environmental, climatic, and limnological reconstructions. Multiproxy analyses of our piston cores document a continuous and detailed record of moisture balance variations in Lake Towuti during the past 60 kyr BP. In detail our datasets show that wet conditions and rainforest ecosystems in central Indonesia persisted during Marine Isotope Stage 3 (MIS3) and the Holocene, and were interrupted by severe

Respiratory virus infection and risk of invasive meningococcal disease in central Ontario, Canada.

Directory of Open Access Journals (Sweden)

Ashleigh R Tuite

Full Text Available BACKGROUND: In temperate climates, invasive meningococcal disease (IMD incidence tends to coincide with or closely follow peak incidence of influenza virus infection; at a seasonal level, increased influenza activity frequently correlates with increased seasonal risk of IMD. METHODS: We evaluated 240 cases of IMD reported in central Ontario, Canada, from 2000 to 2006. Associations between environmental and virological (influenza A, influenza B and respiratory syncytial virus (RSV exposures and IMD incidence were evaluated using negative binomial regression models controlling for seasonal oscillation. Acute effects of weekly respiratory virus activity on IMD risk were evaluated using a matched-period case-crossover design with random directionality of control selection. Effects were estimated using conditional logistic regression. RESULTS: Multivariable negative binomial regression identified elevated IMD risk with increasing influenza A activity (per 100 case increase, incidence rate ratio = 1.18, 95% confidence interval (CI: 1.06, 1.31. In case-crossover models, increasing weekly influenza A activity was associated with an acute increase in the risk of IMD (per 100 case increase, odds ratio (OR  = 2.03, 95% CI: 1.28 to 3.23. Increasing weekly RSV activity was associated with increased risk of IMD after adjusting for RSV activity in the previous 3 weeks (per 100 case increase, OR = 4.31, 95% CI: 1.14, 16.32. No change in disease risk was seen with increasing influenza B activity. CONCLUSIONS: We have identified an acute effect of influenza A and RSV activity on IMD risk. If confirmed, these finding suggest that influenza vaccination may have the indirect benefit of reducing IMD risk.

Mid- to late Holocene climate-driven regime shifts inferred from diatom, ostracod and stable isotope records from Lake Son Kol (Central Tian Shan, Kyrgyzstan)

Science.gov (United States)

Schwarz, Anja; Turner, Falko; Lauterbach, Stefan; Plessen, Birgit; Krahn, Kim J.; Glodniok, Sven; Mischke, Steffen; Stebich, Martina; Witt, Roman; Mingram, Jens; Schwalb, Antje

2017-12-01

Arid Central Asia represents a key region for understanding climate variability and interactions in the Northern Hemisphere. Patterns and mechanisms of Holocene climate change in arid Central Asia are, however, only partially understood. Multi-proxy data combining diatom, ostracod, sedimentological, geochemical and stable isotope analyses from a ca. 6000-year-old lake sediment core from Son Kol (Central Kyrgyzstan) show distinct and repeated changes in species assemblages. Diatom- and ostracod-inferred conductivity shifts between meso-euhaline and freshwater conditions suggest water balance and regime shifts. Organism-derived data are corroborated by stable isotope, mineralogical and geochemical records, underlining that Son Kol was affected by strong lake level fluctuations of several meters. The δ13Ccarb/δ18Ocarb correlation shows repeated switchovers from a closed to an open lake system. From 6000 to 3800 and 3250 to 1950 cal. yr BP, Son Kol was a closed basin lake with higher conductivities, increased nutrient availability and a water level located below the modern outflow. Son Kol became again a hydrologically open lake at 3800 and 1950 cal. yr BP. Comparisons to other local and regional paleoclimate records indicate that these regime shifts were largely controlled by changing intensity and position of the Westerlies and the Siberian Anticyclone that triggered changes in the amount of winter precipitation. A strong influence of the Westerlies ca. 5000-4400, 3800-3250 and since 1950 cal. yr BP enhanced the amount of precipitation during spring, autumn and winter, whereas cold and dry winters prevailed during phases with a strong Siberian Anticyclone and southward shifted Westerlies at ca. 6000-5000, 4400-3800 and 3250-1950 cal. yr BP. Similarities between variations in winter precipitation at Son Kol and records of the predominant NAO-mode further suggest a teleconnection between wet (dry) winter climate in Central Asia and a positive (negative) NAO

Establishment patterns of water-elm at Catahoula Lake, Louisiana

Science.gov (United States)

Karen S. Doerr; Sanjeev Joshi; Richard F. Keim

2015-01-01

At Catahoula Lake in central Louisiana, an internationally important lake for water fowl, hydrologic alterations to the surrounding rivers and the lake itself have led to an expansion of water-elm (Planera aquatic J.F. Gmel.) into the lake bed. In this study, we used dendrochronology and aerial photography to quantify the expansion of water-elm in the lake and identify...

Petrographic Composition of Lignite from the Lake Somerville Spillway (East-central Texas)

Science.gov (United States)

Pawelec, Sandra; Bielowicz, Barbara

2017-12-01

In the presented paper, the macroscopic and microscopic composition of lignite from Lake Somerville Spillway has been examined. The study area is the upper part of the Manning Formation, located north-west of Somerville in the central-eastern part of Texas. There are three exposures: NE, SW and MC (Main Central) with visible parts of late-Eocene lignite seams belonging to the Jackson Group. The Manning section is divided into four marine dominated parasequences (P1 through P4). Lignite samples outlining the P1 parasequence from the MC and NE outcrops and the argillate sample from the lower part of the P2 parasequence, NE outcrop. Macroscopic characterization was carried out based on lithological classifications of humic coal. On this basis, it has been shown that the main lithotype occurring in the deposit is detritic (matrix) coal with a high share of mineral matter. The maceral composition of coal was determined according to the ICCP guidelines. The macerals from liptinite group were determined under fluorescent light. The maceral group content analysis was performed with use of 500-600 equally spaced points on the surface of the polished sections. It has been found that the examined coal is dominated by macerals from the huminite group, with a share ranging from 20.8 to 65.3% volume, including atrinite (9.8-22.8% volume, 17.5% volume on average). In the examined coal, macerals from the inertinite group (10.1 to 44.8%), especially semifusinite (max. 13.9%), fusinite (max. 9.3%) and funginite (max. 6.3 %) are of particularly large share. In the liptinite group, particular attention was paid to the content of alginite (max. 4.5%) and bituminite (max. 1.3 %), which indicate the paralic sedimentation environment of the examined coal. Additionally, the variability of macerals and maceral groups within the exposures and levels of the P1 parasequence was examined. The last step was to compare lignite from Lake Somerville Spillway with other lignites belonging to the

Arcellacea (testate amoebae) as bio-indicators of road salt contamination in lakes.

Science.gov (United States)

Roe, Helen M; Patterson, R Timothy

2014-08-01

Winter deicing operations occur extensively in mid- to high-latitude metropolitan regions around the world and result in a significant reduction in road accidents. Deicing salts can, however, pose a major threat to water quality and aquatic organisms. In this paper, we examine the utility of Arcellacea (testate amoebae) for monitoring lakes that have become contaminated by winter deicing salts, particularly sodium chloride. We analysed 50 sediment samples and salt-related water property variables (chloride concentrations; conductivity) from 15 lakes in the Greater Toronto Area and adjacent areas of southern Ontario, Canada. The sampled lakes included lakes in proximity to major highways and suburban roads and control lakes in forested settings away from road influences. Samples from the most contaminated lakes, with chloride concentrations in excess of 400 mg/l and conductivities of >800 μS/cm, were dominated by species typically found in brackish and/or inhospitable lake environments and by lower faunal diversities (lowest Shannon diversity index values) than samples with lower readings. Q-R-mode cluster analysis and detrended correspondence analysis (DCA) resulted in the recognition of four assemblage groupings. These reflect varying levels of salt contamination in the study lakes, along with other local influences, including nutrient loading. The response to nutrients can, however, be isolated if the planktic eutrophic indicator species Cucurbitella tricuspis is removed from the counts. The findings show that the group has considerable potential for biomonitoring in salt-contaminated lakes, and their presence in lake sediment cores may provide significant insights into long-term benthic community health, which is integral for remedial efforts.

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

Science.gov (United States)

Sediment box cores have frequently been used to determine organochlorine chemical loading histories of lakes and reservoirs. 137Cs and 210Pb radionuclide dating techniques are employed synchronously with chemical analyses of the contaminants for thin sections extruded from adjace...

Fate of Metals in Relation to Water and Sediment Properties in a Subtropical Lake in Central Himalaya, India.

Science.gov (United States)

Inaotombi, Shaikhom; Gupta, Prem Kumar

2017-04-01

Lakes of Himalaya are one of the most fragile ecosystems on earth. Tourism and urban development in the upland region strongly affect its water resources. The high rate of sedimentation and organic matter deposition alters the ecological state of sediment bed, which indirectly influences on dynamics of metallic elements. We investigated spatial and temporal variations of water and sediment characteristic in Lake Sattal of Central Himalaya, India. Samples were collected seasonally from four sampling locations from January 2011 to December 2012. Pearson's correlation and Canonical correspondence analysis (CCAs) were applied to examine the dynamics and behaviors of heavy metals. Concentrations of elements were in the order of fluoride (Fl) > zinc (Zn) > copper (Cu) > iron (Fe) > manganese (Mn). Sand size fraction was higher in the littoral zone while clay particle was dominant in the profundal zone of the lake. Dissolved oxygen at sediment-water-interface (SWI) and water temperature were the major factors influencing the dynamics of metallic contents in the water column. Spatially, total organic matter (TOM) was higher in the deeper portion of the lake. Our study revealed that mobility of Fe is temperature-dependent, whereas speciation of Mn and Cu are primarily controlled by the suboxic condition of SWI in organic-rich site. Upland lakes are more vulnerable to anoxic condition and have severe implications on heavy metals speciation. Proper implementation of land use policies and management practices, including stormwater detention, can be integrated into resolving such problems.

Ontario's new electricity market and the future of OPG

International Nuclear Information System (INIS)

Howes, H.

2002-01-01

The recent measures taken by Ontario Power Generation since 1998 to deregulate the electricity market in the province of Ontario are reviewed. The opening of Ontario's power market in May 2002 will oblige Ontario Power Generation to reduce its market share. The author reviewed the current status of the energy market in Ontario and noted a modest growth in demand. A significant portion of the energy supply is being provided by nuclear, fossil fuels and hydro energy. The challenge facing Ontario Power Generation is to stay competitive in the new deregulated market and to participate in the energy market in the United States. 6 figs

Beware: The empire striking back: An update of regulatory changes in Ontario`s gas and electricity business as at February 1998

Energy Technology Data Exchange (ETDEWEB)

Rosenberg, K. [Gowling, Strathy and Henderson, Toronto, ON (Canada)

1998-09-01

A review of what is happening with regard to deregulation of the gas and electricity industry in Ontario was presented. Recently, a series of government actions in Ontario have recommended fundamental changes in the gas and electric power sector. Prior to the October 31, 1985 agreement, no competitive market existed within local distribution franchises in Ontario or elsewhere in Canada. The Agreement created gas on gas competition and enabled consumers to purchase natural gas from producers at negotiated prices. The Ontario government`s proposed legislation and implementation schedule forecasts even more fundamental changes for the province`s electric power industry. Essentially, the legislation proposes to break up Ontario Hydro into several different entities and transfer regulatory authority to the Ontario Energy Board. The pending legislation also envisages the structural separation of local distribution companies into natural monopolies which will compete in the marketplace. The possibility of privatizing part or all of Ontario`s nuclear assets is also part of the ongoing debate. It was the author`s view that unless there is immediate and complete structural separation of all monopoly services within the gas and electric utilities, the market will not be truly competitive. Instead, regulated monopoly pricing would be replaced by unregulated oligopoly pricing. 1 tab.

Ontario Hydro CANDU operating experience

International Nuclear Information System (INIS)

Bartholomew, R.W.; Woodhead, L.W.; Horton, E.P.; Nichols, M.J.; Daly, I.N.

1987-01-01

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

Ontario Hydro annual report 1975

International Nuclear Information System (INIS)

A financial report and statistics on Ontario energy demand are presented. Efforts to secure a reliable supply of coal and uranium are described. Ontario Hydro's expansion is now controlled by capital availability and not power demand, and this has affected 11 construction projects, including heavy water plants and nuclear generating stations. (E.C.B.)

Ontario hydro radioactive material transportation field guide

International Nuclear Information System (INIS)

Howe, W.

1987-01-01

The recent introduction of both the AECB Transport Packaging of Radioactive Material Regulations and Transport Canada's Transportation of Dangerous Goods Regulations have significantly altered the requirements for transporting radioactive material in Canada. Extensive additional training as well as certification of several hundred Ontario Hydro employees has been necessary to ensure compliance with the additional and revised regulatory requirements. To assist in the training of personnel, an 'active' corporate Ontario Hydro Field Guide for Radioactive Material Transport document has been developed and published. The contents of this Field Guide identify current Ontario Hydro equipment and procedures as well as the updated relevant regulatory requirements within Canada. In addition, to satisfying Ontario Hydro requirements for this type of information over two thousand of these Field Guides have been provided to key emergency response personnel throughout the province of Ontario to assist in their transportation accident response training

Reconnaissance survey for lightweight and carbon tetrachloride extractable hydrocarbons in the central and eastern basins of Lake Erie: September 1978

Energy Technology Data Exchange (ETDEWEB)

Zapotosky, J.E.; White, W.S.

1980-10-01

A reconnaissance survey of the central and eastern basins of Lake Erie (22,240 km/sup 2/) was conducted from September 17 to 27, 1978. The survey provided baseline information on natural gas and oil losses from geologic formations, prior to any potential development of natural gas resources beneath the United States portion of the Lake. Lightweight hydrocarbons indicative of natural gas (methane, ethane, propane, isobutane, and n-butane) are introduced into the waters of Lake Erie by escape from geologic formations and by biological/photochemical processes. The geochemical exploration technique of hydrocarbon sniffing provided enough data to reveal significant distribution patterns, approximate concentrations, and potential sources. Twelve sites with elevated lightweight hydrocarbon concentrations had a composition similar to natural gas. In one area of natural gas input, data analysis suggested a potential negative effect of natural gas on phytoplanktonic metabolism (i.e., ethylene concentration). Samples taken for liquid hydrocarbon analysis (carbon tetrachloride extractable hydrocarbons) correlated best with biologically derived lightweight hydrocarbons.

Environmental magnetic methods for detecting and mapping contaminated sediments in lakes

Science.gov (United States)

Boyce, J. I.

2009-05-01

The remediation of contaminated sediments is an urgent environmental priority in the Great Lakes and requires detailed mapping of impacted sediment layer thickness, areal distribution and pollutant levels. Magnetic property measurements of sediment cores from two heavily polluted basins in Lake Ontario (Hamilton Harbour, Frenchman's Bay) show that concentrations of hydrocarbons (PAH) and a number of heavy metals (Pb, As, Ni, Cu, Cr, Zn, Cd, Fe) are strongly correlated with magnetic susceptibility. The magnetic susceptibility contrast between the contaminated sediment and underlying 'pre-colonial' sediments is sufficient to generate a total field anomaly (ca. 2-20 nT) that can be measured with a magnetometer towed above the lake bed. Systematic magnetic surveying (550 line km) of Hamilton Harbour using a towed marine magnetometer clearly identifies a number of well-defined magnetic anomalies that coincide with known accumulations of contaminated lake sediment. When calibrated against in-situ magnetic property measurements, the modeled apparent susceptibility from magnetic survey results can be used to classify the relative contaminant impact levels. The results demonstrate the potential of magnetic property measurements for rapid reconnaissance mapping of large areas of bottom contamination prior to detailed coring and sediment remediation.

Ontario energy market review and outlook

International Nuclear Information System (INIS)

Brett, J.T.

1997-01-01

The current status of the natural gas industry and the electric power industry in Ontario, in terms of deregulation, was described. Natural gas utilities will exit the regulated gas market over the next few years and transfer their existing residential and small commercial gas contracts to their unregulated affiliates. Nevertheless, a regulated gas supply option will remain until the regulator is assured that consumer protection issues have been properly addressed, and there is a truly competitive market. Ontario Hydro is a vertically integrated virtual monopoly. It lags behind B.C., Alberta, Quebec and Nova Scotia in terms of deregulation and restructuring, although the MacDonald Commission's recent report recommended sweeping changes to Ontario Hydro's monopoly over the electric power industry. A final response from the Ontario government is still pending. The convergence of the electric power and natural gas industries was also discussed

Observations of Lake-Breeze Events During the Toronto 2015 Pan-American Games

Science.gov (United States)

Mariani, Zen; Dehghan, Armin; Joe, Paul; Sills, David

2018-01-01

Enhanced meteorological observations were made during the 2015 Pan and Parapan American Games in Toronto in order to measure the vertical and horizontal structure of lake-breeze events. Two scanning Doppler lidars (one fixed and one mobile), a C-band radar, and a network including 53 surface meteorological stations (mesonet) provided pressure, temperature, humidity, and wind speed and direction measurements over Lake Ontario and urban areas. These observations captured the full evolution (prior, during, and after) of 27 lake-breeze events (73% of observation days) in order to characterize the convective and dynamic processes driving lake breezes at the local scale and mesoscale. The dominant signal of a passing lake-breeze front (LBF) was an increase in dew-point temperature of 2.3 ± 0.3°C, coinciding with a 180° shift in wind direction and a decrease in air temperature of 2.1 ± 0.2°C. Doppler lidar observations over the lake detected lake breezes 1 hour (on average) before detection by radar and mesonet. On days with the synoptic flow in the offshore direction, the lidars observed wedge-shaped LBFs with shallow depths, which inhibited the radar's ability to detect the lake breeze. The LBF's ground speed and inland penetration distance were found to be well-correlated (r = 0.78), with larger inland penetration distances occurring on days with non-opposing (non-offshore) synoptic flow. The observed enhanced vertical motion ({>} 1 m s^{-1}) at the LBF, observed by the lidar on 54% of lake-breeze days, was greater (at times {>} 2.5 m s^{-1}) than that observed in previous studies and longer-lasting over the lake than over land. The weaker and less pronounced lake-breeze structure over land is illustrated in two case studies highlighting the lifetime of the lake-breeze circulation and the impact of propagation distance on lake-breeze intensity.

Fractures and fracture infillings of the Eye-Dashwa Lakes pluton, Atikokan, Ontario

International Nuclear Information System (INIS)

Stone, Denver; Kamineni, D.C.

1982-01-01

Fractures in the Eye-Dashwa pluton near Atikokan, Ontario can be subdivided on the basis of their filling materials. These materials include aplite, epidote, chlorite, and gypsum-carbonate-clay, listed in order of decreasing age established from crosscutting relations. Textues indicate that infilling occurred during fracture growth. Continuous cooling of the pluton during fracturing is inferred from the expected crystallization temperatures of fillings. Fracturing began before the pluton was completely solidified (650-600 0 C) and continued to temperatures below 100 0 C. Many fractures appear to have been sealed by the filling materials after initiation but were subsequently sheared and filled by lower temperatue materials. Apparently the majority of fractures formed during or immediately after pluton solidification and new fractures became smaller and more restricted in location as cooling progressed. Fractures and filling materials are seen as important features in assessing the possibility of movement of radionuclides in aqueous solutions away from a nuclear fuel waste repository

Indications of human activity from amino acid and amino sugar analyses on Holocene sediments from lake Lonar, central India

Science.gov (United States)

Menzel, P.; Gaye, B.; Wiesner, M.; Prasad, S.; Basavaiah, N.; Stebich, M.; Anoop, A.; Riedel, N.; Brauer, A.

2012-04-01

The DFG funded HIMPAC (Himalaya: Modern and Past Climates) programme aims to reconstruct Holocene Indian Monsoon climate using a multi-proxy and multi-archive approach. First investigations made on sediments from a ca. 10 m long core covering the whole Holocene taken from the lake Lonar in central India's state Maharashtra, Buldhana District, serve to identify changes in sedimentation, lake chemistry, local vegetation and regional to supra-regional climate patterns. Lake Lonar occupies the floor of an impact crater that formed on the ~ 65 Ma old basalt flows of the Deccan Traps. It covers an area of ca. 1 km2 and is situated in India's core monsoon area. The modern lake has a maximum depth of about 5 m, is highly alkaline, and hyposaline, grouped in the Na-Cl-CO3 subtype of saline lakes. No out-flowing stream is present and only three small streams feed the lake, resulting in a lake level highly sensitive to precipitation and evaporation. The lake is eutrophic and stratified throughout most of the year with sub- to anoxic waters below 2 m depth. In this study the core sediments were analysed for their total amino acid (AA) and amino sugar (AS) content, the amino acid bound C and N percentage of organic C and total N in the sediment and the distribution of individual amino acids. The results roughly show three zones within the core separated by distinct changes in their AA content and distribution. (i) The bottom part of the core from ca. 12000 cal a BP to 11400 cal a BP with very low AA and AS percentage indicating high lithogenic contribution, most probably related to dry conditions. (ii) From 11400 cal a BP to 1200 cal a BP the sediments show moderate AA and AS percentages and low values for the ratios of proteinogenic AAs to their non-proteinogenic degradation products (e.g. ASP/β-ALA; GLU/γ-ABA). (iii) The top part of the core (land use. This hypothesis is corroborated by the dating of more than 10 temple ruins surrounding the lake, which were built in the 12

Ontario's energy action plan

International Nuclear Information System (INIS)

2003-07-01

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

Acid rain still plaguing lakes and loons

International Nuclear Information System (INIS)

Anon.

2000-01-01

Acid rain monitoring began more than two decades ago by Environment Canada and recent numbers indicate that acid levels in the inland waters barely respond to the reductions in sulphur dioxide (SO 2 ). Under the Canada-U.S. Air Quality Agreement, both countries have committed to reduce SO 2 emissions by 50 per cent over 1980 levels and to reduce nitrogen oxide emissions. Although Canada's goal for SO 2 reductions was achieved in 1994, the nitrogen oxide emissions remained relatively constant. A study of 152 lakes in southeastern Canada indicated that the lakes are only 41 per cent less acidic than they were 20 years ago. The area studied is more vulnerable since it received more acid rain than any other part of the country and the granite bedrock of the Canadian Shield shows a weakness in neutralizing ability. The acidification has caused declines in the populations of fish and invertebrate which loons rely on to survive. A volunteer-based program called Canadian Lakes Loon Survey supported by Environment Canada and other partners began annual monitoring of the breeding success of loons on about 800 lakes. The results showed a decline in the proportion of successful breeding between 1981 and 1997. The decline was more pronounced where the acid level was greatest. Near Sudbury, Ontario, where the emissions of SO 2 declined dramatically, invertebrates started reappearing and fish populations were successfully re-established

Overstory density affects field performance of underplanted red oak (Quercus rubra L.) in Ontario

Science.gov (United States)

Daniel C. Dey; William C. Parker

1997-01-01

Red oak seedlings were underplanted in a closed-canopy mature northern hardwood stand and an adjacent shelterwood in central Ontario. Overstory density effects on seedling survival and growth were assessed 2 yr after planting. After 2 yr, seedling survival was 90% in the uncut stand and over 99% in the shelterwood. Seedlings in the uncut stand experienced negligible or...

[Overview of acupuncture development in Ontario Canada].

Science.gov (United States)

Wang, Fang; Wu, Bin-jiang

2012-04-01

The history of acupuncture in Ontario, Canada was traced, and the current status as welI as the prospection were introduced in this paper. Statistics showed that the history of acupuncture in Ontario started in the 1880s, and it was only popular in China Town and Chinese community. In the 1970s, it gradually merged into the mainstream of the society, and entered into a growing period. With the tide of Chinese immigration in the 1980s and 1990s, acupuncture matured rapidly. In 2006, the "Traditional Chinese Medicine Act" was passed in Ontario, it was considered as a milestone in the history of acupuncture. At present, just like the other 23 health care professions, acupuncture has already be included into the legislation system, and become a component of Ontario's health care system. At the same time, the law and regulation may also promote the establishment of "pure Chinese Medicine" in Ontario.

The Oligochaeta (Annelida, Clitellata) of the St. Lawrence Great Lakes region: An update

Science.gov (United States)

Spencer, Douglas R.; Hudson, Patrick L.

2003-01-01

An updated oligochaete species list for the Great Lakes region is provided. The list was developed through the reexamination of the taxa reported in a previous report in 1980, addition of new taxa or records collected from the region since 1980, and an update of taxonomy commensurate with systematic and nomenclatural changes over the intervening years since the last review. The authors found 74 papers mentioning Great Lakes oligochaete species. The majority of these papers were published in the 1980s. The literature review and additional collections resulted in 15 species being added to the previous list. Nine taxa were removed from the previous list due to misidentification, synonymies, level of identification, or inability to confirm the identity. Based on this review, 101 species of Oligochaeta are now known from the St. Lawrence Great Lakes watershed. Of these, 95 species are known from the St. Lawrence Great Lakes proper, with an additional 6 species recorded from the inland waters of the watershed. The greatest diversity of oligochaete species was found in the inland waters of the region (81) followed by Lake Huron (72), Lake Ontario (65), Lake Erie (64), Lake Superior (63), Lake Michigan (62), St. Marys River (60), Niagara River (49), Saginaw Bay (44), St. Clair River (37), Lake St. Clair (36), St. Lawrence River (27), and the Detroit River (21). Three species are suspected of being introduced, Branchiura sowerbyi, Gianius aquaedulcisand Ripistes parasita, and two are believed to be endemic, Thalassodrilus hallae andTeneridrilus flexus.

Market prices for solar electricity in Ontario

International Nuclear Information System (INIS)

Rowlands, I.H.

2006-01-01

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

The restructuring of the Ontario electricity market

International Nuclear Information System (INIS)

Doucet, J.A.

1999-01-01

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

Ontario Hydro CANDU operating experience

International Nuclear Information System (INIS)

Jackson, H.A.; Woodhead, L.W.; Fanjoy, G.R.

1984-03-01

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

Cooperatives and the State: The Case of Ontario

Directory of Open Access Journals (Sweden)

Rachel Laforest

2011-01-01

Full Text Available In the early 2000s, the cooperative movement in Ontario came together in order to lobby its provincial government for active cooperative development support programs. Momentum was building for these types of programs. Already, many provincial governments had implemented active support programs in their jurisdiction. Despite having one of the largest cooperative sectors in Canada, Ontario was lagging behind. This article assesses the progress of the efforts of the Ontario cooperative movement to date. It details how the Ontario cooperative movement developed a sectoral identity for itself and framed its objectives in an effort to strengthen its relationship with the Ontario government. / Le mouvement coopératif en Ontario s'est rassemblé au début des années 2000 afin de faire pression sur le gouvernement provincial pour qu'il développe des programmes de soutient actif pour coopératives. Déjà plusieurs gouvernements provinciaux avaient mis en place de telles politiques. L'Ontario tardait malgré le fait qu'il avait un des plus grands secteurs coopératifs au Canada. Cet article examine le progrès qu'a connu le mouvement coopératif en Ontario dans ses efforts. Il décrit comment le mouvement coopératif a construit une identité sectorielle autour de laquelle il a pu ancrer ses demandes auprès du gouvernement ontarien.

Chemical and biotic characteristics of prairie lakes and large wetlands in south-central North Dakota—Effects of a changing climate

Science.gov (United States)

Mushet, David M.; Goldhaber, Martin B.; Mills, Christopher T.; McLean, Kyle I.; Aparicio, Vanessa M.; McCleskey, R. Blaine; Holloway, JoAnn M.; Stockwell, Craig A.

2015-09-28

The climate of the prairie pothole region of North America is known for variability that results in significant interannual changes in water depths and volumes of prairie lakes and wetlands; however, beginning in July 1993, the climate of the region shifted to an extended period of increased precipitation that has likely been unequaled in the preceding 500 years. Associated changing water volumes also affect water chemical characteristics, with potential effects on fish and wildlife populations. To explore the effect of changing climate patterns, in 2012 and 2013, the U.S. Geological Survey revisited 167 of 178 prairie lakes and large wetlands of south-central North Dakota that were originally sampled in the mid-1960s to mid-1970s. During the earlier sampling period, these lakes and wetlands displayed a great range of chemical characteristics (for example, specific conductance ranged from 365 microsiemens per centimeter at 25 degrees Celsius to 70,300 microsiemens per centimeter at 25 degrees Celsius); however, increased water volumes have resulted in greatly reduced variation among lakes and wetlands and a more homogeneous set of chemical conditions defined by pH, specific conductance, and concentrations of major cations and anions. High concentrations of dissolved solids previously limited fish occurrence in many of the lakes and wetlands sampled; however, freshening of these lakes and large wetlands has allowed fish to populate and flourish where they were previously absent. Conversely, the freshening of previously saline lakes and wetlands has resulted in concurrent shifts away from invertebrate species adapted to live in these highly saline environments. A shift in the regional climate has changed a highly diverse landscape of wetlands (fresh to highly saline) to a markedly more homogeneous landscape that has reshaped the fish and wildlife communities of this ecologically and economically important region.

Electronic archival tags provide first glimpse of bathythermal habitat use by free-ranging adult lake sturgeon Acipenser fulvescens

Science.gov (United States)

Briggs, Andrew S.; Hondorp, Darryl W.; Quinlan, Henry R.; Boase, James C.; Mohr, Lloyd C.

2016-01-01

Information on lake sturgeon (Acipenser fulvescens) depth and thermal habitat use during non-spawning periods is unavailable due to the difficulty of observing lake sturgeon away from shallow water spawning sites. In 2002 and 2003, lake sturgeon captured in commercial trap nets near Sarnia, Ontario were implanted with archival tags and released back into southern Lake Huron. Five of the 40 tagged individuals were recaptured and were at large for 32, 57, 286, 301, and 880 days. Temperatures and depths recorded by archival tags ranged from 0 to 23.5 ºC and 0.1 to 42.4 m, respectively. For the three lake sturgeon that were at large for over 200 days, temperatures occupied emulated seasonal fluctuations. Two of these fish occupied deeper waters during winter than summer while the other occupied similar depths during non-spawning periods. This study provides important insight into depth and thermal habitat use of lake sturgeon throughout the calendar year along with exploring the feasibility of using archival tags to obtain important physical habitat attributes during non-spawning periods.

The tempo of Holocene climatic change in the eastern Mediterranean region : new high-resolution crater-lake sediment data from central Turkey

NARCIS (Netherlands)

Reed, JM; Leng, MJ; Kuzucuoglu, C; Fontugne, M; Bertaux, J; Bottema, S; Black, S; Hunt, E; Karabiyikoglu, M; Woldring, H.

2001-01-01

This study presents results from a multi-proxy analysis of cores taken in a crater-lake sequence from Eski Acigol in central Turkey which cover the period from pre-c. 16000 cal. yr BP to the present. The sediments comprise an upper unit of generally non-laminated, banded to massive silts and peats

Widespread waterborne pollution in central Swedish lakes and the Baltic Sea from pre-industrial mining and metallurgy.

Science.gov (United States)

Bindler, Richard; Renberg, Ingemar; Rydberg, Johan; Andrén, Thomas

2009-07-01

Metal pollution is viewed as a modern problem that began in the 19th century and accelerated through the 20th century; however, in many parts of the globe this view is wrong. Here, we studied past waterborne metal pollution in lake sediments from the Bergslagen region in central Sweden, one of many historically important mining regions in Europe. With a focus on lead (including isotopes), we trace mining impacts from a local scale, through a 120-km-long river system draining into Mälaren--Sweden's third largest lake, and finally also the Baltic Sea. Comparison of sediment and peat records shows that pollution from Swedish mining was largely waterborne and that atmospheric deposition was dominated by long-range transport from other regions. Swedish ore lead is detectable from the 10th century, but the greatest impact occurred during the 16th-18th centuries with improvements occurring over recent centuries, i.e., historical pollution > modern industrial pollution.

Revitalizing the nuclear business at Ontario Hydro

International Nuclear Information System (INIS)

Talbot, K.

1994-01-01

Ontario Hydro, North America's largest electric power utility, with an installed capacity of 34,000 MW, has under gone a major restructuring over the past year to better align itself with a changing electricity market and evolving customer needs. The single largest new business unit within the new Ontario Hydro is Ontario Hydro Nuclear (OHN), responsible for engineering, operation and maintenance of the Corporation's 20 large nuclear units at three generating sites, OHN faces a significant challenge in returning Ontario's nuclear units to the world-leading performance levels they enjoyed in the past, particularly the older Pickering A and Bruce A plants. However, steady progress is being made as evidenced by improving peer reviews and overall capacity and financial performance

Environmental and spatial factors influencing the distribution of cladocerans in lakes across the central Canadian Arctic treeline region

Directory of Open Access Journals (Sweden)

John P. SMOL

2010-02-01

Full Text Available We examine the role of local environmental and spatial factors in explaining variation in the composition of cladoceran assemblages from surface sediments within a set of 50 lakes spanning a broad southwest to northeast transect across the central Canadian Arctic treeline region from Yellowknife (Northwest Territories to the northern boundary of the Thelon Game Sanctuary (Nunavut Territory. Within each lake, the cladoceran fauna was identified based on the subfossil exoskeletal remains preserved in recently deposited lake sediments. Physical and chemical limnological data were measured in August of 1996 and 1998. Spatial data were generated based on latitude and longitude using Principal Coordinates of Neighbors Matrices analysis (PCNM. The relationships between cladocerans and the measured environmental and spatial variables were examined using both unconstrained (Principal Components Analysis, PCA and constrained (Redundancy Analysis, RDA ordination techniques. Variance partitioning, based on partial RDAs, was used to identify the relative importance of significant environmental and spatial explanatory variables. Three environmental variables were identified as significantly influencing cladoceran community structure: surface water temperature, dissolved organic carbon (DOC, and total phosphorus (TP. Five PCNM-generated spatial variables were also significant in explaining cladoceran distributions. Variance partitioning attributed 14% of the variance in the distribution of Cladocera to spatial factors, an additional 10% to spatially-structured environmental variables, and 8% to environmental factors that were not spatially-structured. Within the central Canadian Arctic treeline region, spatial and other environmental processes had an important influence on the distribution of cladoceran communities. The strong influence of spatial factors was related to the large ecoclimatic gradient across treeline. The distribution patterns of cladocerans

Climate change and human occupations in the Lake Daihai basin, north-central China over the last 4500 years: A geo-archeological perspective

Science.gov (United States)

Xu, Lichen; Liu, Yan; Sun, Qianli; Chen, Jing; Cheng, Peng; Chen, Zhongyuan

2017-05-01

High-resolution climate variations since the last 4500 years in the monsoonal-arid transition zone of north-central China were revealed through the integration of proxies from sediment cores in the Lake Daihai basin. Human occupations in the lake basin deduced from archeological findings and historical literatures were then incorporated into the climate sequence to demonstrate the patterns of human responses to the climate changes, and the recent anthropogenic effects. It indicated that: (1) Climate dominated human-environment adaptations prevailed prior to ∼2700 cal yr BP. An amicable climate setting before ∼4100 cal yr BP would facilitate the growth of the Laohushan Culture (LC) in the lake basin, while a pronounced deterioration of water thermal condition after that had led to human exodus and the collapse of the LC. The reduced human activity in the lake basin indicated at ∼3800-3500 cal yr BP and a subsequent cultural blank at ∼3500-2700 cal yr BP, were both in response to the climate and lake level fluctuations during ∼3800-2800 cal yr BP. (2) Transition to a positive human adaptation was seen at ∼2700-1100 cal yr BP, represented by the exploitation of arable land for cultivation and animal husbandry as the lake contracted. (3) An increasing human presence that affected environmental processes became more severe over the last ∼1100 cal yr BP. This was basically due to the ongoing lake shore reclamation for cropping, and more recently heavy metals emissions from fossil fuel combustion and local industries.

Mercury contamination in the Laurentian Great Lakes region: Introduction and overview

International Nuclear Information System (INIS)

Wiener, James G.; Evers, David C.; Gay, David A.; Morrison, Heather A.; Williams, Kathryn A.

2012-01-01

The Laurentian Great Lakes region of North America contains substantial aquatic resources and mercury-contaminated landscapes, fish, and wildlife. This special issue emanated from a bi-national synthesis of data from monitoring programs and case studies of mercury in the region, here defined as including the Great Lakes, the eight U.S. states bordering the Great Lakes, the province of Ontario, and Lake Champlain. We provide a retrospective overview of the regional mercury problem and summarize new findings from the synthesis papers and case studies that follow. Papers in this issue examine the chronology of mercury accumulation in lakes, the importance of wet and dry atmospheric deposition and evasion to regional mercury budgets, the influence of land–water linkages on mercury contamination of surface waters, the bioaccumulation of methylmercury in aquatic foods webs; and ecological and health risks associated with methylmercury in a regionally important prey fish. - Highlights: ► We describe a bi-national synthesis of Hg data from the Great Lakes region. ► Emission controls have reduced Hg inputs to inland lakes about 20% since the 1980s. ► Wet and dry deposition and evasion are regionally important atmospheric Hg fluxes. ► Land use affects Hg inputs to surface waters and bioaccumulation of methylmercury. ► In some waters, Hg levels in yellow perch pose risks to fish, wildlife, and humans. - A synthesis of Hg data from the Great Lakes region reveals the chronology of contamination; the importance of wet and dry deposition and evasion to Hg budgets; the influence of land–water linkages; bioaccumulation in aquatic foods webs; and risks associated with Hg in an important prey fish.

Management applications for thermal IR imagery of lake processes

Science.gov (United States)

Whipple, J. M.; Haynes, R. B.

1971-01-01

A thermal infrared scanning program was conducted in the Lake Ontario Basin region in an effort to determine: (1) limonologic data that could be collected by remote sensing techniques, and (2) local interest in and routine use of such data in water management programs. Difficulties encountered in the development of an infrared survey program in New York suggest that some of the major obstacles to acceptance of remotely sensed data for routine use are factors of psychology rather than technology. Also, terminology used should suit the measurement technique in order to encourage acceptance of the surface thermal data obtained.

A geochemical record of the link between chemical weathering and the East Asian summer monsoon during the late Holocene preserved in lacustrine sediments from Poyang Lake, central China

Science.gov (United States)

Huang, Chao; Wei, Gangjian; Li, Wuxian; Liu, Ying

2018-04-01

This paper presents relatively high-resolution geochemical records spanning the past 4000 cal yr BP obtained from the lacustrine sediments of Poyang Lake in central China. The variations in the intensity of the East Asian summer monsoon (EASM) are traced using the K/Na, Ti/Na, Al/K, kaolinite/illite and clay/feldspar ratios, together with the chemical index of alteration (CIA), as indicators of chemical weathering. During the last 4000 years, the proxy records of chemical weathering from Poyang Lake exhibit an overall enhanced trend, consistent with regional hydrological changes in previous independent records. Further comparisons and analyses demonstrate that regional moisture variations in central China is inversely correlated with the EASM intensity, with weak EASM generating high precipitation in central China. Our data reveal three intervals of dramatically dry climatic conditions (i.e., ca. 4000-3200 cal yr BP, ca. 2800-2400 cal yr BP, and ca. 500-200 cal yr BP). A period of weak chemical weathering, related to cold and dry climatic conditions, occurred during the Little Ice Age (LIA), whereas more intense chemical weathering, reflecting warm and humid climatic conditions, was recorded during the Medieval Warm Period (MWP). Besides, an intensification of chemical weathering in Poyang Lake during the late Holocene agrees well with strong ENSO activity, suggesting that moisture variations in central China may be predominantly driven by ENSO variability.

[Ontario Hydro International Inc.]. Annual report 1993

International Nuclear Information System (INIS)

1994-01-01

Ontario Hydro International Inc. is the international representative of Ontario Hydro. OHII operates as a global utility that markets Ontario Hydro's services and products. Its mission is to be the leader in energy efficiency and sustainable development in the international marketplace. This report describes the year's activities in the following areas: Energy management and environment, hydroelectric generation, nuclear products and services, fossil generation, grid (transmission) business, utility management, Asia Power Group Inc. The document also includes financial highlights and international and customer contracts

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

Science.gov (United States)

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

2018-04-01

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

Lakes near the glacier Maliy Azau on the Elbrus (Central Caucasus: dynamics and outbursts

Directory of Open Access Journals (Sweden)

M. D. Dokukin

2016-01-01

Full Text Available The lake dynamics and the current state of them were analyzed on the basis of interpretation of aerial and satellite images of different years together with results of field surveys. Areas of six lakes existing in different years near the Maliy Azau Glacier had been determined. On August 22, 2011, the maximum area of one of the lakes was equal to 25.5 thousand m2. The first outburst was caused by the landslide deformations of the moraine massif forming a part of the lake basin, while the second one was a result of degradation of the lake ice dam and the water overflow on top of it. The present‑day lake dams (terminal‑moraine ramparts and medial moraine ridges are the result of the Maliy Azau Glacier advance in 1990s. The revealed feature of the lake dynamics on the mountain Elbrus was a drop of the water level and corresponding decrease of the lake areas in winter that was related to existence of the groundwater runoff into fractured volcanic rocks. At present, moraine dams of lakes and areas of the surface water runoff from the lakes are in stable condition due to which there is no threat of a lake outburst. However, the potential threat of outburst still remains because of high seismicity and possible volcanic activity in this region.

A new species of Cletocamptus Schmankewitsch, 1875 (Crustacea, Copepoda, Harpacticoida from a high altitude saline lake in Central Mexico

Directory of Open Access Journals (Sweden)

Eduardo Suarez Morales

2013-04-01

Full Text Available During the analysis of littoral samples collected from a high-altitude saline crater lake in Central Mexico, several female and male specimens of harpacticoid copepods were recovered and taxonomically examined. They were found to represent an undescribed species of the canthocamptid genus Cletocamptus Schmankewitsch, 1875. The new species, C. gomezi n. sp. is described herein based on specimens of both sexes. It resembles C. stimpsoni Gómez, Fleeger, Rocha-Olivares and Foltz, 2004 from Louisiana but also C. trichotus Kiefer, 1929. The new species differs from C. stimpsoni and from other congeners by details of the maxillular armature, the setation of the endopodal segments of legs 2 and 3, and the armature of the third exopodal segment of legs 3 and 4. Also, the dorsal (VII and the outer (IV caudal setae are both relatively shorter than in C. stimpsoni. This is the second species of the genus known to be distributed in Mexico. The occurrence of the new species in a high-altitude saline lake, the isolation of the type locality, and its absence from adjacent freshwater lakes suggest that this species is endemic to this site.

"Strengthening" Ontario Universities: A Neoliberal Reconstruction of Higher Education

Science.gov (United States)

Rigas, Bob; Kuchapski, Renée

2016-01-01

This paper reviews neoliberalism as an ideology that has influenced higher education generally and Ontario higher education in particular. It includes a discourse analysis of "Strengthening Ontario's Centres of Creativity, Innovation and Knowledge" (Ontario Ministry of Training, Colleges, and Universities, 2012), a government discussion…

Characteristics and ontogeny of oligotrophic hardwater lakes in the Forsmark area, central Sweden

Energy Technology Data Exchange (ETDEWEB)

Brunberg, A.K.; Blomqvist, P. [Uppsala Univ. (Sweden). Dept. of Limnology

1999-12-01

This is the first part of a report characterising the lakes of Uppsala county, with special emphasis on the coastal lakes in the Forsmark area.The aim of the study is to characterise different main types of lakes within the Forsmark area and to create a basis for prediction of their ontogeny, that can be used also for new lakes which due to shoreline displacement will be formed during the next 10 000 years. Areas where future research is needed to fully understand the functioning of the lake ecosystems and their ontogeny should also be identified. This first part of the study identifies and describes one of the most common lake types in the area, the oligotrophic hardwater lake. The geology in the catchments of the Forsmark area includes a bedrock dominated by granites and gneisses, covered by calcareous glacial till and postglacial clay. The catchments are dominated by forest, and the oligotrophic hardwater lakes are to a large extent surrounded by mires. Inflow as well as outflow of water is often diffuse, via the surrounding mire. The lakes are small and shallow, with nutrient poor and highly alkaline water. Three key habitats have been identified within the lakes; the pelagic zone, characterised by low production of biota;, the presumably moderately productive emergent macrophyte zone, dominated by Sphagnum and Phragmites;, and the light exposed soft-bottom zone with Chara meadows and an unusually rich and presumably highly productive microbial sediment community. The oligotrophic hardwater lakes have their origin as depressions in the bottom of the Baltic Sea, which are successively transported upwards due to the land-rise process in the area. As the basins are isolated from the sea , a gradual change from a brackish to freshwater conditions occur. When the lakes have become completely isolated, the oligotrophic hardwater stage follows, due to inflow of carbonate-rich and well buffered groundwater. In the next successional stage, Sphagnum mosses start to

Characteristics and ontogeny of oligotrophic hardwater lakes in the Forsmark area, central Sweden

International Nuclear Information System (INIS)

Brunberg, A.K.; Blomqvist, P.

1999-12-01

This is the first part of a report characterising the lakes of Uppsala county, with special emphasis on the coastal lakes in the Forsmark area.The aim of the study is to characterise different main types of lakes within the Forsmark area and to create a basis for prediction of their ontogeny, that can be used also for new lakes which due to shoreline displacement will be formed during the next 10 000 years. Areas where future research is needed to fully understand the functioning of the lake ecosystems and their ontogeny should also be identified. This first part of the study identifies and describes one of the most common lake types in the area, the oligotrophic hardwater lake. The geology in the catchments of the Forsmark area includes a bedrock dominated by granites and gneisses, covered by calcareous glacial till and postglacial clay. The catchments are dominated by forest, and the oligotrophic hardwater lakes are to a large extent surrounded by mires. Inflow as well as outflow of water is often diffuse, via the surrounding mire. The lakes are small and shallow, with nutrient poor and highly alkaline water. Three key habitats have been identified within the lakes; the pelagic zone, characterised by low production of biota;, the presumably moderately productive emergent macrophyte zone, dominated by Sphagnum and Phragmites;, and the light exposed soft-bottom zone with Chara meadows and an unusually rich and presumably highly productive microbial sediment community. The oligotrophic hardwater lakes have their origin as depressions in the bottom of the Baltic Sea, which are successively transported upwards due to the land-rise process in the area. As the basins are isolated from the sea , a gradual change from a brackish to freshwater conditions occur. When the lakes have become completely isolated, the oligotrophic hardwater stage follows, due to inflow of carbonate-rich and well buffered groundwater. In the next successional stage, Sphagnum mosses start to

X-ray safety in Ontario

International Nuclear Information System (INIS)

1980-03-01

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.)

Ontario Hydro decontamination experience

Energy Technology Data Exchange (ETDEWEB)

Lacy, C S; Patterson, R W; Upton, M S [Chemistry and Metallurgy Department, Central Production Services, Ontario Hydro, ON (Canada)

1991-04-01

Ontario Hydro currently operates 18 nuclear electric generating units of the CANDU design with a net capacity of 12,402 MW(e). An additional 1,762 MW(e) is under construction. The operation of these facilities has underlined the need to have decontamination capability both to reduce radiation fields, as well as to control and reduce contamination during component maintenance. This paper presents Ontario Hydro decontamination experience in two key areas - full heat transport decontamination to reduce system radiation fields, and component decontamination to reduce loose contamination particularly as practised in maintenance and decontamination centres. (author)

Ontario Hydro decontamination experience

International Nuclear Information System (INIS)

Lacy, C.S.; Patterson, R.W.; Upton, M.S.

1991-01-01

Ontario Hydro currently operates 18 nuclear electric generating units of the CANDU design with a net capacity of 12,402 MW(e). An additional 1,762 MW(e) is under construction. The operation of these facilities has underlined the need to have decontamination capability both to reduce radiation fields, as well as to control and reduce contamination during component maintenance. This paper presents Ontario Hydro decontamination experience in two key areas - full heat transport decontamination to reduce system radiation fields, and component decontamination to reduce loose contamination particularly as practised in maintenance and decontamination centres. (author)

Selling from Ontario into the U.S. midwest

International Nuclear Information System (INIS)

Green, B.

2002-01-01

The market structure of the Midwest Independent System Operator (MISO) for the electric power grid was described with reference to physical bilateral markets, multi-control areas, and MISO services such as security coordination, congestion management, billing, generator interconnections, tariff administration, energy imbalance, market monitoring, and electronic scheduling. The drivers impacting MISO development include MISO-PJM-SPP common market initiative, the FERC Standard Market Design initiative, the integration of alliance companies with MISO, and the division of functional responsibilities between RTOs and ITCs. The characteristics of the Michigan market were described, along with participation in the midwest (Ohio and Michigan) wholesale and retail markets. It was noted that in order for Ontario to sell to the midwest, the Ontario market design would need a successful export bid each hour to get power out of the province. Sales of ancillary services from Ontario-based generation are not permitted in the initial Ontario market design. Energy and transmission is currently bundled in Ontario tariffs. 1 fig

Selling from Ontario into the U.S. midwest

Energy Technology Data Exchange (ETDEWEB)

Green, B. [Ontario Power Generation Inc., Toronto, ON (Canada)

2002-07-01

The market structure of the Midwest Independent System Operator (MISO) for the electric power grid was described with reference to physical bilateral markets, multi-control areas, and MISO services such as security coordination, congestion management, billing, generator interconnections, tariff administration, energy imbalance, market monitoring, and electronic scheduling. The drivers impacting MISO development include MISO-PJM-SPP common market initiative, the FERC Standard Market Design initiative, the integration of alliance companies with MISO, and the division of functional responsibilities between RTOs and ITCs. The characteristics of the Michigan market were described, along with participation in the midwest (Ohio and Michigan) wholesale and retail markets. It was noted that in order for Ontario to sell to the midwest, the Ontario market design would need a successful export bid each hour to get power out of the province. Sales of ancillary services from Ontario-based generation are not permitted in the initial Ontario market design. Energy and transmission is currently bundled in Ontario tariffs. 1 fig.

Restructuring in Ontario : electricity sector reform

International Nuclear Information System (INIS)

Pospisil, S.

2004-01-01

Ontario's electricity reform strategy was outlined along with challenge facing Ontario's electricity supply and demand with particular focus on the issue of replacing coal-fired generation. According to reports by the Independent Electricity Market Operator, short-term reserve margins were higher in 2004 than they were in 2003 due to the return to service of some nuclear generating units and planned capacity additions. Ontario's long-term supply and demand situation was also examined. It was noted that lenders hesitate to finance the expansion of generation companies selling into the spot market. Many lenders are requiring that half of the project's output be sold in advance on contract. Other challenges include Ontario's aging generation infrastructure and rising energy prices. The presentation included graphs that compared electricity costs for residential and small business customers across various provinces and states. The main supply and conservation challenges revolve around the large investments required by 2020 to replace coal plants, retire nuclear plants and projected load growth. Ontario's current generation capacity is 154 TWh and the mix is represented by 40 per cent nuclear, 25 per cent coal, 25 per cent hydro, 8 per cent natural gas, 1 per cent oil, and 1 per cent biomass and other renewable energy sources. This paper also addressed the issue of coal generation and air pollution and emphasized the importance of looking at the broad externalities associated with air emissions. tabs., figs

Hydromagnesite precipitation in the Alkaline Lake Dujiali, central Qinghai-Tibetan Plateau: Constraints on hydromagnesite precipitation from hydrochemistry and stable isotopes

International Nuclear Information System (INIS)

Lin, Yongjie; Zheng, Mianping; Ye, Chuanyong

2017-01-01

The mineral hydromagnesite, Mg 5 (CO 3 ) 4 (OH) 2 ·4H 2 O, is a common form of hydrated Mg-carbonate in alkaline lakes, yet the processes involved in its formation are not well understood. This study focuses on Dujiali Lake, in the central Qinghai-Tibetan Plateau (QTP), which is one of the few environments on the earth's surface with extensive Holocene precipitation of hydromagnesite. The hydrogeochemistry of surface waters, and the mineralogical, stable isotope (δ 13 C and δ 18 O), and radiogenic isotope content of hydromagnesite deposits were analyzed to investigate formation mechanisms. The chemical composition of surface water around Dujiali Lake evolved from the rock-weathering-type waters of T1 (Ca−Mg−HCO 3 water type) to more concentrated sodic waters of T2 (Na−SO 4 −Cl water type) due to evaporation. XRD results show that the mineralogical composition of samples is pure hydromagnesite. Analysis of oxygen isotopes in the hydromagnesite indicates that supergene formation with authigenic carbonate crystallization from evaporation water is the dominant precipitation process. Combined carbon-oxygen isotope analysis suggests atmospheric CO 2 provided a carbon source for the precipitation of hydromagnesite. These findings suggest that hydromagnesite precipitation at Lake Dujiali is mainly inorganic in nature, and the greenhouse gas, CO 2 , is trapped and stored in the hydromagnesite directly from the atmosphere. AMS radiocarbon dating of samples indicates CO 2 was sequestered between 5845 ± 30 to 6090 ± 25 cal a BP in the Dujiali Lake hydromagnesite deposit. The study contributes to improved understanding of hydromagnesite formation in modern and ancient playas. - Highlights: • The stable isotopes, radiogenic isotope data are firstly obtained from the hydromagnesite deposits of Lake Dujiali in QTP. • Hydromagnesite precipitation at Lake Dujiali is mainly inorganic. • δ 18 O indicates supergene formation with authigenic carbonate

Creating a competitive electricity market in Ontario - The energy consumer perspective

International Nuclear Information System (INIS)

Ford, M.

1997-01-01

The large consumers' perspective on the Ontario Government's decision to delay action on restructuring the electric power industry was provided, and recommendations were offered as to the best course of action that the Government ought to take. Ontario Hydro's proposal to restructure itself into separate generation, transmission and retail corporations, and to introduce competition into the Corporation was attacked as unworkable, in that it could not help but encourage price manipulation. The large consumer group also argued that retail distribution in Ontario needs major rationalization without an Ontario Hydro presence. In place of the Ontario Hydro proposal the Association of Major Power Consumers in Ontario (AMPCO) recommends a separate transmission system including an independent system operator, a restructuring of local distribution within a definite time frame and consistent criteria, to be worked out by municipal utilities and Ontario Hydro Retail, and establishment of a Transition Authority independent of Ontario Hydro with a mandate to carry out these changes. While the Ontario Government appears to be unlikely to undertake such a'risky' initiative at this stage of its mandate, significant change, including competition, remains inevitable. It is not a question of whether, but when a fully competitive energy market in Ontario will become a reality. tabs., figs

Demand-side management and demand response in the Ontario energy sectors

International Nuclear Information System (INIS)

2004-01-01

A directive from the former Minister of Energy was received by the Ontario Energy Board (OEB), directing the Board to consult with stakeholders on options for the delivery of demand-side management (DSM) and demand response (DR) activities within the electricity sector, including the role of local distribution companies in such activities. The implementation costs were to be balanced with the benefits to both consumers and the entire system. The scope of the review was expanded by the Board to include the role of gas distribution companies in DSM. A consultation process was implemented and stakeholders were invited to participate. A series of recommendations was made, including: (1) a hybrid framework utilizing market-based and public-policy approaches should deliver DSM and DR activities in Ontario's energy markets, (2) DSM and DR activities should come under the responsibility of a central agency, (3) DSM and DR activities should be coordinated through cooperation between the Ministry of Energy, the Independent Electricity Market Operator (IMO) and the Ontario Energy Board, (4) regulatory mechanisms to induce gas distributors, electricity transmitters and electricity distributors to reduce distribution system losses should be put in place, (5) all electricity consumers should fund electricity DSM and some retail DR initiatives through a transparent, non-bypassable consumption charge, and (6) the Board should design, develop and deliver information to consumers regarding energy conservation, energy efficiency, load management, and cleaner sources of energy. refs., 4 figs

Cross currents : hydroelectricity and the engineering of northern Ontario

Energy Technology Data Exchange (ETDEWEB)

Manore, J.L. [Calgary Univ., AB (Canada)

1999-05-01

The history of hydroelectric development in northern Ontario was reviewed and analysed with special emphasis on the developments along the Mattagami and Abitibi Rivers. The objective was to examine the important factors that shaped modern hydroelectric development in Canada. System builders, the privately owned Nesbitt Thomson Company, the publicly owned Hydro Electric Power Corporation of Ontario and the eventual evolution of the single power system under Ontario Hydro are chronicled. Broad historical themes such as the technological impacts, regionalism, indigenous rights, plus environmental and economic issues are examined, in addition to an appreciation of the importance of electricity in the manufacturing sector of Ontario, the impact of hydroelectric development on the northern environment and on the northern First Nations, who rely on rivers for their subsistence. Until fairly recently, government policies and interpretations of law often excluded the recognition of Aboriginal uses of river systems, thereby limiting First Nations` peoples ability to practice traditional ways of life. In essence, the book is an account of how the northeastern power system in Ontario shaped the social, political and natural environments and how the development of northeastern power sources by southern power developers shaped the regional interactions between Ontario`s north and south. refs., figs.

Methylmercury speciation in the dissolved phase of a stratified lake using the diffusive gradient in thin film technique

Energy Technology Data Exchange (ETDEWEB)

Clarisse, Olivier [Trent University, Department of Chemistry, 1600 West Bank Drive, Peterborough, Ontario K9J 7B8 (Canada)], E-mail: olivier.clarisse@umoncton.ca; Foucher, Delphine; Hintelmann, Holger [Trent University, Department of Chemistry, 1600 West Bank Drive, Peterborough, Ontario K9J 7B8 (Canada)

2009-03-15

The diffusive gradient in thin film (DGT) technique was successfully used to monitor methylmercury (MeHg) speciation in the dissolved phase of a stratified boreal lake, Lake 658 of the Experimental Lakes Area (ELA) in Ontario, Canada. Water samples were conventionally analysed for MeHg, sulfides, and dissolved organic matter (DOM). MeHg accumulated by DGT devices was compared to MeHg concentration measured conventionally in water samples to establish MeHg speciation. In the epilimnion, MeHg was almost entirely bound to DOM. In the top of the hypolimnion an additional labile fraction was identified, and at the bottom of the lake a significant fraction of MeHg was potentially associated to colloidal material. As part of the METAALICUS project, isotope enriched inorganic mercury was applied to Lake 658 and its watershed for several years to establish the relationship between atmospheric Hg deposition and Hg in fish. Little or no difference in MeHg speciation in the dissolved phase was detected between ambient and spike MeHg. - Methylmercury speciation was determined in the dissolved phase of a stratified lake using the diffusive gradient in thin film technique.

Methylmercury speciation in the dissolved phase of a stratified lake using the diffusive gradient in thin film technique

International Nuclear Information System (INIS)

Clarisse, Olivier; Foucher, Delphine; Hintelmann, Holger

2009-01-01

The diffusive gradient in thin film (DGT) technique was successfully used to monitor methylmercury (MeHg) speciation in the dissolved phase of a stratified boreal lake, Lake 658 of the Experimental Lakes Area (ELA) in Ontario, Canada. Water samples were conventionally analysed for MeHg, sulfides, and dissolved organic matter (DOM). MeHg accumulated by DGT devices was compared to MeHg concentration measured conventionally in water samples to establish MeHg speciation. In the epilimnion, MeHg was almost entirely bound to DOM. In the top of the hypolimnion an additional labile fraction was identified, and at the bottom of the lake a significant fraction of MeHg was potentially associated to colloidal material. As part of the METAALICUS project, isotope enriched inorganic mercury was applied to Lake 658 and its watershed for several years to establish the relationship between atmospheric Hg deposition and Hg in fish. Little or no difference in MeHg speciation in the dissolved phase was detected between ambient and spike MeHg. - Methylmercury speciation was determined in the dissolved phase of a stratified lake using the diffusive gradient in thin film technique

Is there a future for coal in Ontario?

International Nuclear Information System (INIS)

Davies, G.

2004-01-01

This PowerPoint presentation examined the efficacy of a governmental decision in 2003 to close all Ontario coal stations by 2007. Coal currently represents one quarter of Ontario's energy and capacity. Projected supply and demand gaps for Ontario were presented for up to 2020. Ontario's supply options were outlined. It was noted that between $30 and $40 billion in investment in the electricity sector will be needed over the next 10 to 15 years. It was observed that closing coal plants may reduce pollution by 6 per cent at a cost of $2 billion. More than half the smog affecting Ontario comes from the United States, while much of the remaining half is caused by transportation emissions. Details of energy strategies related to coal in the United States were discussed. New coal power plant technologies include supercritical combustion; advanced air pollution control; circulating fluidized bed combustion and integrated coal gasification combined cycles. Coal power plant performance criteria were presented. Various research programs in the United States were reviewed, and roadmap performance targets were presented. It was concluded that high prices and uncertainty for natural gas fired options may reinforce views on the need to rethink coal closures. A strategy was recommended in which Ontario pursued economic options for reducing emissions across all sectors. New investments in latest and best technology for emissions reduction in Ontario's coal-fired stations were recommended, as well as a North American agreement on clean air, and increased Canadian participation in U.S. technology development efforts for clean coal and zero emissions plants by 2025. tabs., figs

Design, construction and operation of Ontario Hydro's CANDU plants

International Nuclear Information System (INIS)

Campbell, P.G.

1981-06-01

Ontario Hydro has been producing electricity commercially from nuclear power since 1968, using CANDU reactors which have proved enormously successful. The 206-MW Douglas Point station, nearly 10 times larger than the first Canadian power reactor, NPD-2, resulted from a cooperative effort between Atomic Energy of Canada Ltd., the provincial government of Ontario, and Ontario Hydro. This approach led to a basic working relationship between the parties, with Ontario Hydro acting as project manager and builder, and AECL acting as consultant with respect to the nuclear components. Before Douglas Point was fully commissioned Ontario Hydro was ready to commit itself to more nuclear stations, and work was started on the four-unit Pickering nuclear generating station. Multi-unit stations were adopted to achieve economies of scale, and the concept has been retained for all subsequent nuclear power plants constructed in the province. The organization of Ontario Hydro's project management, construction, and operation of nuclear generating stations is described. Performance of the existing stations and cost of the power they produce have been entirely acceptable

MORPHOLOGICAL VARIATION IN HATCHLING AMERICAN ALLIGATORS (ALLIGATOR MISSISSIPPIENSIS) FROM THREE FLORIDA LAKES

Science.gov (United States)

Morphological variation of 508 hatchling alligators from three lakes in north central Florida (Lakes Woodruff, Apopka, and Orange) was analyzed using multivariate statistics. Morphological variation was found among clutches as well as among lakes. Principal components analysis wa...

Estimation of water storage changes in small endorheic lakes in Burabay National Nature Park (Northern Kazakhstan, Central Asia); the effect of climate change and anthropogenic influences

Science.gov (United States)

Yapiyev, Vadim; Sagintayev, Zhanay; Verhoef, Anne; Samarkhanov, Kanat; Jumassultanova, Saltanat

2017-04-01

Both climate change and anthropogenic activities contribute to deterioration of terrestrial water resources and ecosystems worldwide. It has been observed in recent decades that water-limited steppe regions of Central Asia are among ecosystems found to exhibit enhanced responses to climate variability. In fact, the largest share of worldwide net loss of permanent water extent is geographically concentrated in the Central Asia and Middle East regions attributed to both climate variability/change and human activities impacts. We used a digital elevation model, digitized bathymetry maps and high resolution Landsat images to estimate the areal water cover extent and volumetric storage changes in small terminal lakes in Burabay National Nature Park (BNNP), located in Northern Central Asia, for the period 2000-2016. Based on the analysis of long-term climatic data from meteorological stations, hydrometeorological network observations as well as regional climate model projections we evaluate the impacts of past thirty years and future climatic conditions on the water balance of BNNP lake catchments. The anthropogenic water consumption was estimated based on data collected at a local water supply company and regulation authorities. One the one hand historical in-situ observations and future climate projections do not show a significant change in precipitation in BNNP. On the other hand both observations and the model demonstrate steadily rising air temperatures in the area. It is concluded that the long-term decline in water levels for most of these lakes can be largely attributed to climate change (but only via changes in air temperature, causing evaporation to exceed precipitation) and not to direct anthropogenic influences such as increased water withdrawals. In addition, the two largest lakes, showing the highest historical water level decline, do not have sufficient water drainage basin area to sustain water levels under increased evaporation rates.

Heat wave generates questions about Ontario's generation capacity

International Nuclear Information System (INIS)

Horne, D.

2005-01-01

Concerns regarding Ontario's power generation capacity were raised following a major blackout which occurred in August 2003. Power demand reached 26,170 MW during the weeks leading to the blackout, forcing the Independent Electricity System Operator (IESO) to ask residents to reduce electricity use during the day. The grid operator had also issued a forecast that Toronto could face rolling blackouts during times of heavy power demand. Ontario power consumption records were set in June and July of 2003 due to a heat wave, with hourly demand exceeding 25,000 MW on 53 occasions. Ontario was forced to import up to 3,400 MW (13 per cent of its power needs) from neighbouring provinces and the United States. During that period, the price of power had risen sharply to over 30 cents a kilowatt hour, although household consumers were still charged in the 5 to 10 cent range per kilowatt hour. However, it was noted that taxpayers will eventually bear the cost of importing power. The IESO noted that importing electricity is cheaper than the generation available in Ontario and that it is more economical to import, based on the market clearing price of all generators. In 2004, the IESO purchased 6 per cent of their electricity from the United States. That figure is expected to increase for 2005. Ontario generators produced 26.9 million MWh more in the summer of 2005 than during the same period in 2004 to meet electricity demand levels. It was noted that although importing power presently meets peak demand, the IESO agrees there is a need for new generation within Ontario. In addition to restarting Ontario's Pickering and Bruce nuclear facilities, more than 3,300 MW of new gas-fired generation is under construction or approved, and more than 9,000 MW are in various stages of approval. This paper discussed the effect of high energy costs on industry and Ontario's ability to meet future electricity demand in comparison to neighbouring jurisdictions. Issues regarding grid maintenance

Water level monitoring using radar remote sensing data: Application to Lake Kivu, central Africa

Science.gov (United States)

Munyaneza, Omar; Wali, Umaru G.; Uhlenbrook, Stefan; Maskey, Shreedhar; Mlotha, McArd J.

Satellite radar altimetry measures the time required for a pulse to travel from the satellite antenna to the earth’s surface and back to the satellite receiver. Altimetry on inland lakes generally shows some deviation from in situ level measurements. The deviation is attributed to the geographically varying corrections applied to account for atmospheric effects on radar waves. This study was focused on verification of altimetry data for Lake Kivu (2400 km 2), a large inland lake between Rwanda and the Democratic Republic of Congo (DRC) and estimating the lake water levels using bathymetric data combined with satellite images. Altimetry data obtained from ENVISAT and ERS-2 satellite missions were compared with water level data from gauging stations for Lake Kivu. Gauge data for Lake Kivu were collected from the stations ELECTROGAZ and Rusizi. ENVISAT and ERS-2 data sets for Lake Kivu are in good agreement with gauge data having R2 of 0.86 and 0.77, respectively. A combination of the two data sets improved the coefficient of determination to 95% due to the improved temporal resolution of the data sets. The calculated standard deviation for Lake Kivu water levels was 0.642 m and 0.701 m, for ENVISAT and ERS-2 measurements, respectively. The elevation-surface area characteristics derived from bathymetric data in combination with satellite images were used to estimate the lake level gauge. Consequently, the water level of Lake Kivu could be estimated with an RMSE of 0.294 m and an accuracy of ±0.58 m. In situations where gauges become malfunctioning or inaccessible due to damage or extreme meteorological events, the method can be used to ensure data continuity.

Risk of colorectal cancer among immigrants to Ontario, Canada.

Science.gov (United States)

Paszat, Lawrence; Sutradhar, Rinku; Liu, Ying; Baxter, Nancy N; Tinmouth, Jill; Rabeneck, Linda

2017-07-06

The risk of colorectal cancer (CRC) varies around the world and between females and males. We aimed to compare the risk of CRC among immigrants to Ontario, Canada, to its general population. We used an exposure-control matched design. We identified persons in the Immigration, Refugees and Citizenship Canada Permanent Resident Database with first eligibility for the Ontario Health Insurance Plan between July 1, 1991 and June 30, 2008 at age 40 years or older, and matched five controls by year of birth and sex on the immigrant's first eligibility date. We identified CRC from the Ontario Cancer Registry between the index date and December 31, 2014. All analyses were stratified by sex. We calculated crude and relative rates of CRC. We estimated risk of CRC over time by the Kaplan-Meier method and compared immigrants to controls in age and sex stratified strata using log-rank tests. We modeled the hazard of CRC using Cox proportional hazards regression, accounting for within-cluster correlation by a robust sandwich variance estimation approach, and assessed an interaction with time since eligibility. Among females, 1877 cases of CRC were observed among 209,843 immigrants, and 16,517 cases among 1,049,215 controls; the crude relative rate among female immigrants was 0.623. Among males, 1956 cases of CRC were observed among 191,792 immigrants and 18,329 cases among 958,960 controls; the crude relative rate among male immigrants was 0.582.. Comparing immigrants to controls in all age and sex stratified strata, the log rank test p  = 75 years at index, where p = 0.01. The age-adjusted hazard ratio (HR) for CRC among female immigrants was 0.63 (95% CI 0.59, 0.67) during the first 10 years, and 0.66 (95% CI 0.59, 0.74) thereafter. Among male immigrants the age-adjusted HR = 0.55 (95% CI 0.52, 0.59) during the first 10 years and increased to 0.63 (95% CI 0.57, 0.71) thereafter. The adjusted HR > = 1 only among immigrants born in Europe and Central Asia. The risk

Lake sediment records on climate change and human activities in the Xingyun Lake catchment, SW China.

Directory of Open Access Journals (Sweden)

Wenxiang Zhang

Full Text Available Sediments from Xinyun Lake in central Yunnan, southwest China, provide a record of environmental history since the Holocene. With the application of multi-proxy indicators (total organic carbon (TOC, total nitrogen (TN, δ13C and δ15N isotopes, C/N ratio, grain size, magnetic susceptibility (MS and CaCO3 content, as well as accelerator mass spectrometry (AMS 14C datings, four major climatic stages during the Holocene have been identified in Xingyun's catchment. A marked increase in lacustrine palaeoproductivity occurred from 11.06 to 9.98 cal. ka BP, which likely resulted from an enhanced Asian southwest monsoon and warm-humid climate. Between 9.98 and 5.93 cal. ka BP, a gradually increased lake level might have reached the optimum water depth, causing a marked decline in coverage by aquatic plants and lake productivity of the lake. This was caused by strong Asian southwest monsoon, and coincided with the global Holocene Optimum. During the period of 5.60-1.35 cal. ka BP, it resulted in a warm and dry climate at this stage, which is comparable to the aridification of India during the mid- and late Holocene. The intensifying human activity and land-use in the lake catchment since the early Tang Dynasty (∼1.35 cal. ka BP were associated with the ancient Dian culture within Xingyun's catchment. The extensive deforestation and development of agriculture in the lake catchment caused heavy soil loss. Our study clearly shows that long-term human activities and land-use change have strongly impacted the evolution of the lake environment and therefore modulated the sediment records of the regional climate in central Yunnan for more than one thousand years.

Lake sediment records on climate change and human activities in the Xingyun Lake catchment, SW China.

Science.gov (United States)

Zhang, Wenxiang; Ming, Qingzhong; Shi, Zhengtao; Chen, Guangjie; Niu, Jie; Lei, Guoliang; Chang, Fengqin; Zhang, Hucai

2014-01-01

Sediments from Xinyun Lake in central Yunnan, southwest China, provide a record of environmental history since the Holocene. With the application of multi-proxy indicators (total organic carbon (TOC), total nitrogen (TN), δ13C and δ15N isotopes, C/N ratio, grain size, magnetic susceptibility (MS) and CaCO3 content), as well as accelerator mass spectrometry (AMS) 14C datings, four major climatic stages during the Holocene have been identified in Xingyun's catchment. A marked increase in lacustrine palaeoproductivity occurred from 11.06 to 9.98 cal. ka BP, which likely resulted from an enhanced Asian southwest monsoon and warm-humid climate. Between 9.98 and 5.93 cal. ka BP, a gradually increased lake level might have reached the optimum water depth, causing a marked decline in coverage by aquatic plants and lake productivity of the lake. This was caused by strong Asian southwest monsoon, and coincided with the global Holocene Optimum. During the period of 5.60-1.35 cal. ka BP, it resulted in a warm and dry climate at this stage, which is comparable to the aridification of India during the mid- and late Holocene. The intensifying human activity and land-use in the lake catchment since the early Tang Dynasty (∼1.35 cal. ka BP) were associated with the ancient Dian culture within Xingyun's catchment. The extensive deforestation and development of agriculture in the lake catchment caused heavy soil loss. Our study clearly shows that long-term human activities and land-use change have strongly impacted the evolution of the lake environment and therefore modulated the sediment records of the regional climate in central Yunnan for more than one thousand years.

Annual report 1993 (Ontario Hydro, Toronto)

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-12-31

Ontario Hydro`s prime objective is to supply the people of Ontario with electricity at cost while maintaining high standards of safety and service. The annual report presents energy efficiency and competitiveness, operations in review, the environmental performance of the Corporation, the future, and choices for a sustainable future. A financial review and analysis is also provided, along with an auditor`s report and financial statements.

Great Lakes waters: radiation dose commitments, potential health effects, and cost-benefit considerations

International Nuclear Information System (INIS)

Ainsworth, E.J.

1977-07-01

In 1972, a Great Lakes Water Quality Agreement was signed by the United States and Canadian Governments. It was stipulated that the operation and effectiveness of the agreement were to be reviewed comprehensively in 1977. Aspects of the agreement concern nondegradation of Great Lakes waters and maintenance of levels of radioactivity or other potential pollutants at levels considered as low as practicable. A refined radioactivity objective of one millirem is proposed in the Water Quality Agreement. The implications of adoption of this objective are not known fully. The Division of Environmental Impact Studies was commissioned by ERDA's Division of Technology Overview to summarize the information available on the current levels of radioactivity in Great Lakes waters, compute radiation-dose commitment (integrated dose over 50 years after consumption of 2.2 liters of water of one year), and to comment on the feasibility and cost-benefit considerations associated with the refined one-millirem objective. Current levels of radioactivity in the waters of Lakes Michigan, Ontario, Erie, and Huron result in dose commitments in excess of 1 mrem for whole body and 6 mrem for bone. Future projections of isotope concentrations in Great lakes water indicate similar dose commitments for drinking water in the year 2050. Reduction of the levels of radioactivity in Great Lakes waters is not feasible, but cost-benefit considerations support removal of 226 Ra and 90 Sr through interceptive technology before water consumption. Adoption of the one-millirem objective is not propitious

Assessing Ontario's Personal Support Worker Registry

Directory of Open Access Journals (Sweden)

Audrey Laporte

2013-08-01

Full Text Available In response to the growing role of personal support workers (PSWs in the delivery of health care services to Ontarians, the Ontario government has moved forward with the creation of a PSW registry. This registry will be mandatory for all PSWs employed by publicly funded health care employers, and has the stated objectives of better highlighting the work that PSWs do in Ontario, providing a platform for PSWs and employers to more easily access the labour market, and to provide government with information for human resources planning. In this paper we consider the factors that brought the creation of a PSW registry onto the Ontario government’s policy agenda, discuss how the registry is being implemented, and provide an analysis of the strengths and weaknesses of this policy change.

A demand/supply and price outlook for electricity in Ontario

International Nuclear Information System (INIS)

Dalton, J.

2004-01-01

This paper presents the demand/supply and price outlook for electricity in Ontario. The paper examines the near term outlook, critical demand and supply issues, the projected Ontario demand/supply balances and finally concludes by looking at the challenges for Ontario's new market structure

Zooplankton community response to experimental acidification in boreal shield lakes with different ecological histories

Energy Technology Data Exchange (ETDEWEB)

Derry, A.M.; Arnott, S.E. [Queen' s Univ., Kingston, ON (Canada). Dept. of Biology

2007-06-15

This study investigated the adaptive response of crustacean zooplankton to widespread regional acidification at the Killarney Provincial Park in Ontario. Mesocosm experiments were conducted in 2 circumneutral lakes with different acidification histories. A reciprocal transplant field enclosure experiment was conducted to assess whether the zooplankton community within the acid-recovering boreal shield lake showed evidence of increased acid tolerance to historical acidification following a 6 year period in which the lake's pH was 6.0. The enclosures were filled with epilimnetic water from the lake. Zooplankton from other lakes in the area were used. Zooplankton and water samples were collected from the enclosures once a week. Shannon-Wiener indices, species richness, and total abundance of the zooplankton were calculated for each sample day. Repeated measures analyses of variance (RM-ANOVAs) were used to test for the effects of the incubation lake, the zooplankton source, and the pH. Species abundance data were log{sub 10} transformed to improve homogeneity of variances and normality. Principle components analysis was conducted on species abundances to infer the influence of treatments on zooplankton community composition. Zooplankton were also transferred from 1 lake to the other in order to determine if subtle differences in local water chemistry and food conditions were limiting the recovery of species in acid-recovering lakes. The study showed that 2 key species, H. gibberum and L. minutus, contributed to community-level differences to acid tolerance of zooplankton with different acidification histories. It was concluded that zooplankton with adaptable acid tolerances may monopolize resources in acidified and acid-recovering lakes, and may contribute to the delayed recolonization of other taxa. 62 refs., 3 tabs., 6 figs.

Examining Competition in Ontario's Higher Education Market

Science.gov (United States)

Farhan, Bayan Yousef

2017-01-01

Financial challenges have forced many publicly funded academic institutions in Ontario to adopt a corporate model and to use market tools to compete in the higher education market and maintain their enrolment and revenue levels. This study has analyzed how competition affects publicly funded universities in Ontario. Competition was examined by…

More than energy: Ontario Hydro final annual report, January 1998 - March 1999

International Nuclear Information System (INIS)

1999-01-01

Ontario Hydro ceased operations on March 31, 1999 and its assets and functions were transferred by provincial statute to two successor corporations: Ontario Power Generation Corp. (OPG) and Ontario Hydro Services Inc. Its functions were also transferred to the Independent Electricity Market Operator and the Electrical Safety Authority, two not-for-profit agencies. The original act defining Ontario Hydro was replaced by the Energy Competition Act, 1998. Until the demerger of the company on April 1, 1999, Ontario Hydro served 108 direct industrial clients, almost one million retail clients and 255 municipal utilities. Ontario Power Generation inherited Ontario Hydro's generating portfolio, making it one of the largest power producers in North America in terms of installed capacity. The OPG system includes 69 hydroelectric stations, three nuclear sites, and six operating fossil fueled stations. Total installed system capacity is approximately 31,000 megawatts, and Ontario Hydro's total sales in 1998 were almost 139 terawatt hours. Ontario Hydro Services Company is an energy services-based transmission and distribution company. It owns and maintains 29,000 km of transmission lines, 114,700 km of distribution lines, 245 km of high-voltage underground cable, 256 transformer stations, 928 distribution and regulation stations, and 250 microwave stations. It also retains the retail business held by Ontario Hydro, which serves over 950,000 clients, and the transmission and generating business for 23 remote communities in Northern Ontario

Plastics Distribution and Degradation on Lake Huron Beaches

Science.gov (United States)

Zbyszewski, M.; Corcoran, P.

2009-05-01

The resistivity of plastic debris to chemical and mechanical weathering processes poses a serious threat to the environment. Numerous marine beaches are littered with plastic fragments that entangle and become ingested by organisms including birds, turtles and plankton. Although many studies have been conducted to determine the amount and effects of plastics pollution on marine organisms, relatively little is known about the distribution and quantity of polymer types along lacustrine beaches. Plastic particles sampled from selected beaches on Lake Huron were analyzed using Fourier Transform Infrared Spectroscopy (FTIR) to determine polymer composition. The majority of the plastic fragments are industrial pellets composed of polypropylene and polyethylene. Varying degrees of oxidation are indicated by multiple irregular peaks in the lower wavenumber region on the FTIR spectra. The oxidized pellets also represent the plastic particles with the most pronounced surface textures, as identified using Scanning Electron Microscopy (SEM). Crazes and flakey, fibrous, or granular textures are consistent with chemical weathering processes, whereas gauges and pits occur through abrasion during mechanical weathering. Further textural and compositional analysis will indicate which polymer types are more resistant to weathering processes. Additional investigation of the distribution of plastic debris along the beaches of Lake Huron will indicate the amount and primary transport directions of resistant plastic debris polluting one of Ontario's Great Lakes.

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.

Branchial cadmium and copper binding and intestinal cadmium uptake in wild yellow perch (Perca flavescens) from clean and metal-contaminated lakes

International Nuclear Information System (INIS)

Klinck, J.S.; Green, W.W.; Mirza, R.S.; Nadella, S.R.; Chowdhury, M.J.; Wood, C.M.; Pyle, G.G.

2007-01-01

Branchial binding kinetics and gastro-intestinal uptake of copper and cadmium where examined in yellow perch (Perca flavescens) from a metal-contaminated lake (Hannah Lake, Sudbury, Ontario, Canada) and an uncontaminated lake (James Lake, North Bay, Ontario, Canada). An in vivo approach was taken for gill binding comparisons while an in vitro gut binding assay was employed for gastro-intestinal tract (GIT) uptake analysis. By investigating metal uptake at the gill and the gut we cover the two main routes of metal entry into fish. Comparisons of water and sediment chemistries, metal burdens in benthic invertebrate, and metal burdens in the livers of perch from the two study lakes clearly show that yellow perch from Hannah L. are chronically exposed to a highly metal-contaminated environment compared to a reference lake. We found that metal-contaminated yellow perch showed no significant difference in gill Cd binding compared to reference fish, but they did show significant decreases in new Cd binding and absorption in their GITs. The results show that gill Cd binding may involve low-capacity, high-affinity binding sites, while gastro-intestinal Cd uptake involves binding sites that are high-capacity, low-affinity. From this we infer that Cd may be more critically controlled at the gut rather than gills. Significant differences in branchial Cu binding (increased binding) were observed in metal-contaminated yellow perch. We suggest that chronic waterborne exposure to Cu (and/or other metals) may be the dominant influence in gill Cu binding rather than chronic exposure to high Cu diets. We give supporting evidence that Cd is taken up in the GIT, at least in part, by a similar pathway as Ca 2+ , principally that elevated dietary Ca 2+ reduces Cd binding and uptake. Overall our study reveals that metal pre-exposure via water and diet can alter uptake kinetics of Cu and Cd at the gill and/or the gut

Branchial cadmium and copper binding and intestinal cadmium uptake in wild yellow perch (Perca flavescens) from clean and metal-contaminated lakes

Energy Technology Data Exchange (ETDEWEB)

Klinck, J.S. [Department of Biology, McMaster University, Hamilton, Ont. L8S 4K1 (Canada)], E-mail: klinckjs@mcmaster.ca; Green, W.W.; Mirza, R.S. [Department of Biology, McMaster University, Hamilton, Ont. L8S 4K1 (Canada); Department of Biology, Nipissing University, North Bay, Ont. P1B 8L7 (Canada); Nadella, S.R.; Chowdhury, M.J.; Wood, C.M. [Department of Biology, McMaster University, Hamilton, Ont. L8S 4K1 (Canada); Pyle, G.G. [Department of Biology, Nipissing University, North Bay, Ont. P1B 8L7 (Canada)

2007-08-30

Branchial binding kinetics and gastro-intestinal uptake of copper and cadmium where examined in yellow perch (Perca flavescens) from a metal-contaminated lake (Hannah Lake, Sudbury, Ontario, Canada) and an uncontaminated lake (James Lake, North Bay, Ontario, Canada). An in vivo approach was taken for gill binding comparisons while an in vitro gut binding assay was employed for gastro-intestinal tract (GIT) uptake analysis. By investigating metal uptake at the gill and the gut we cover the two main routes of metal entry into fish. Comparisons of water and sediment chemistries, metal burdens in benthic invertebrate, and metal burdens in the livers of perch from the two study lakes clearly show that yellow perch from Hannah L. are chronically exposed to a highly metal-contaminated environment compared to a reference lake. We found that metal-contaminated yellow perch showed no significant difference in gill Cd binding compared to reference fish, but they did show significant decreases in new Cd binding and absorption in their GITs. The results show that gill Cd binding may involve low-capacity, high-affinity binding sites, while gastro-intestinal Cd uptake involves binding sites that are high-capacity, low-affinity. From this we infer that Cd may be more critically controlled at the gut rather than gills. Significant differences in branchial Cu binding (increased binding) were observed in metal-contaminated yellow perch. We suggest that chronic waterborne exposure to Cu (and/or other metals) may be the dominant influence in gill Cu binding rather than chronic exposure to high Cu diets. We give supporting evidence that Cd is taken up in the GIT, at least in part, by a similar pathway as Ca{sup 2+}, principally that elevated dietary Ca{sup 2+} reduces Cd binding and uptake. Overall our study reveals that metal pre-exposure via water and diet can alter uptake kinetics of Cu and Cd at the gill and/or the gut.

Waste management practices in Ontario`s workplaces: An emerging industrial ecology

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-09-01

Describes a study commissioned to evaluate employee attitudes and behaviours with respect to participation in workplace initiatives in waste diversion/reduction, to examine management initiatives related to waste diversion and reduction/recycling/reuse, and to report on Ontario Ministry of Environment & Energy activities related to industrial, commercial, and institutional (ICI) waste diversion activities. Linkages between management and employees, management and government, and ICI activities and government were also studied. The study methodology included a literature review, a series of interviews with key stakeholders, industry associations, and waste management companies, and a series of 12 case studies spanning major industrial sectors in Ontario. Issues addressed in the study include the factors that trigger waste diversion activities by ICI establishments, barriers to the initiation of waste diversion practices, and the social aspects of waste reduction/recycling/reuse practices.

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-07-01

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

Ontario's changing electrical sector : implications for air quality and human health

International Nuclear Information System (INIS)

Perrota, K.; De Leon, F.

1999-03-01

Concerns regarding the changes to Ontario's electricity sector and the impacts that these changes may have on the environment and public health are discussed. Two of the major changes include the implementation of the Nuclear Asset Optimization Plan, and the introduction of competition to Ontario's electrical market. Both changes could have profound impacts on air quality in Toronto and the rest of Ontario. This report recommends that the Ontario Minister of Environment and the Ontario Minister of Energy, Science and Technology establish: a regulatory framework to ensure that competition in Ontario's electrical sector does not lead to greater reliance on coal-fired generating stations and further degradation of air quality, human health and the environment in Toronto and the rest of southern Ontario; annual air emission caps for the entire electrical sector to limit the volume of air pollutants released each year; a renewable energy standard which defines the percentage of electricity that must be generated with renewable energies by electrical suppliers serving Ontario consumers; and a public benefit fund to support the promotion of energy conservation and the development of renewable energies with a surcharge on the transmission of electricity. 35 refs., 5 tabs

Compendium of Statistical and Financial Information: Ontario Universities, 2001-02.

Science.gov (United States)

Council of Ontario Universities, Toronto.

This compendium presents data about aspects of the Ontario University System, Canada. It is a companion to the "Financial Report of Ontario Universities," the annual series of volumes prepared under the auspices of the Council of Financial OfficersUniversities of Ontario (COFO-UO). The Compendium contains supplementary information on…

Deregulation experiences in Alberta and Ontario

International Nuclear Information System (INIS)

Axford, D.

2003-01-01

A brief introduction of Nexen Chemicals, one of the largest producers of sodium chlorate in the world, was offered, and a map displaying its locations throughout the world was displayed. Nexen is one of Canada's largest independent oil and gas producers, while Nexen Marketing is involved in the marketing of natural gas in North America. In January 2001, the deregulated market opened in Alberta. High natural gas prices, generation shortages, high prices in California and an upcoming provincial election all combined to complicate the situation. A high degree of volatility characterized the market. A chart displaying weekly average Alberta power and gas prices from Jan 2002 to 13 Oct 2002 was shown. In Ontario, the market opened in May 2002, and the demand growth rate was in the 1 to 2 per cent range. The author indicated that approximately 20 per cent of homeowners in Ontario have signed deals with retailers, contrary to Alberta where very few have done so. A similar chart displaying weekly average Ontario power prices was presented. The issues in Ontario are: consistency in policy, increase market transparency, transmission / distribution price flexibility, overall transmission / distribution to industrial consumers high, and increasing costs of the system operator. In Alberta, the issues are: government intent, congestion management issues, and billing settlement errors that continue. The opportunities offered by a deregulated market include process responsiveness which is rewarded, the ability to look in forward prices when prices fit margin requirement, and gives companies the opportunity to participate in the development of the market. Various charts were also displayed to further illustrate the market in both Alberta and Ontario. figs

A critical review of the development, current hotspots, and future directions of Lake Taihu research from the bibliometrics perspective.

Science.gov (United States)

Zhang, Yunlin; Yao, Xiaolong; Qin, Boqiang

2016-07-01

Lake Taihu, as the important drinking water source of the Yangtze River Delta urban agglomeration and the third largest freshwater lake in China, has experienced serious lake eutrophication and water quality deterioration in the past three decades. Growing scientific, political, and public attention has been given to the water quality of Lake Taihu. This study aimed to conduct a comparative quantitative and qualitative analysis of the development, current hotspots, and future directions of Lake Taihu research using a bibliometric analysis of eight well-studied lakes (Lake Taihu, Lake Baikal, Lake Biwa, Lake Erie, Lake Michigan, Lake Ontario, Lake Superior and Lake Victoria) around the world based on the Science Citation Index (SCI) database. A total of 1582 papers discussing Lake Taihu research were published in 322 journals in the past three decades. However, the first paper about Lake Taihu research was not found in the SCI database until 1989, and there were only zero, one, or two papers each year from 1989 to 1995. There had been rapid development in Lake Taihu research since 1996 and a sharp increase in papers since 2005. A keyword analysis showed that "sediment," "eutrophication", "Microcystis aeruginosa", "cyanobacterial blooms", and "remote sensing" were the most frequently used keywords of the study subject. Owing to its significant impact on aquatic ecosystems, a crucial emphasis has been placed on climate change recently. In addition, the future focuses of research directions, including (1) environmental effects of physical processes; (2) nutrient cycles and control and ecosystem responses; (3) cyanobacteria bloom monitoring, causes, forecast and management; (4) eutrophication and climate change interactions; and (5) ecosystem degradation mechanism and ecological practice of lake restoration, are presented based on the keyword analysis. Through multidisciplinary fields (physics, chemistry, and biology) cross and synthesis study of Lake Taihu, the

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

Fifteen years of radioactive waste management at Ontario Hydro

International Nuclear Information System (INIS)

Carter, T.J.; Rao, P.K.M.

1985-01-01

Ontario Hydro is a large Canadian utility producing 84% (7394 MWe) of the Nuclear Electricity generated in Canada. The low- and intermediate-level radioactive wastes generated by the Ontario Hydro program are currently being managed at the Bruce Nuclear Power Development with various volume reduction, packaging and interim storage systems. Ontario Hydro also owns and operates a radioactive waste transportation system. Studies are in progress for final disposal of these wastes in a suitable geology in Ontario. Since its inception in 1971, Ontario Hydro's radioactive waste management program has evolved into providing a full fledged radioactive waste management capability to the utility's two nuclear generation centres at Pickering and Bruce, and later in the decade, to Darlington. This paper summarizes the various developments in this program; highlights the major facilities both in-service and planned to be built; reviews the experiences gained over fifteen years of in-house waste management; and discusses the proposed reorientation towards ultimate disposal of these wastes. 2 refs., 8 figs., 1 tab

The potential of solar PV in Ontario

International Nuclear Information System (INIS)

McMonagle, R.

2005-01-01

Canada has lagged behind other industrialized nations in the growth of solar energy markets. Currently, over 78 per cent of the global market for solar energy is for grid-connected applications where power is fed into the electrical distribution network. Less than 3.5 per cent of the Canadian solar market is grid-connected. This report investigated the potential size of the photovoltaic (PV) market in Ontario given adequate support from both governments and utilities. The forecast was based on sustainable growth levels that the solar industry as a whole might maintain over an extended period of time. It was suggested that it is technically feasible to install over 3000 MW of PV in single, detached homes in the province, which could generate over 3200 GWh each year. If the right policy conditions were put in place, the technical potential for PV on all buildings in Ontario is over 14,000 MW by 2025, which would generate over 13,000 GWh annually. Support mechanisms such as the Advanced Renewable Tariff (ART) or Standard Offer Contracts (SOC) will enable the PV industry to build capacity. Future markets for PV include new homes, commercial buildings and the existing housing stock. With a properly designed system, it is forecasted that the deployment of PV by 2025 could result in the involvement of 400,000 homes with over 1200 MW of installed capacity and over 290 MW installed annually by 2025. Recommendations to Ontario Power Authority's (OPA) report supply mix report focused on the use of SOCs as the appropriate support mechanism to start building solar capacity in Ontario, as projections using SOCs would see Ontario following the growth patterns of other nations. It was concluded that the OPA report does not acknowledge the current growth rates of PV globally, nor does it fully consider the potential of PV in Ontario. 9 refs., 8 figs

Ontario Hydro Research Division annual report 1988

International Nuclear Information System (INIS)

1988-01-01

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

Opening Doors to Nursing Degrees: A Proposal from Ontario's Colleges

Science.gov (United States)

Colleges Ontario, 2010

2010-01-01

Ontario needs to expand nursing education options to improve access to the nursing profession, create better pathways amongst all nursing occupations, and build Ontario's capacity to meet the province's long-term nursing needs. Ontario's colleges are capable of playing a larger role within a long-term provincial strategy for sustaining and…

Compendium of Statistical and Financial Information: Ontario Universities, 2000-01.

Science.gov (United States)

Council of Ontario Universities, Toronto.

This compendium presents data on various aspects of the Ontario University System, Canada. It is a companion to the Financial Report of Ontario Universities, the annual series of volumes prepared under the auspices of the Council of Financial Officers-Universities of Ontario (COFO-UO). This compendium contains supplementary information that helps…

ECOLOGY OF CLADOPHORA GLOMERATA (L.) KÜTZ IN SOUTHERN ONTARIO(1).

Science.gov (United States)

Bellis, V J; McLarty, D A

1967-06-01

Cladophora glomerata (L.) Kütz. was the dominant attached alga in streams and along lake shores in southern Ontario. Maximum production occurred in summer and resulted from 2 short periods of intensive vegetative growth (June and September). Optimum habitat conditions consist of a firm substrate in shallow alkaline water. These conditions are provided by harbor facilities where man-made structures supplement naturally occurring rock outcrops or cobble beaches and where nutrients are available from tributaries draining agricultural and urban land areas. Periodicity appears to be related to temperature; the interval between the 2 periods of intensive growth during warm weather decreases at successively more northern locations. Frequent observation of Cladophora growing at a single stream station revealed that variations in thallus morphology and relative cell dimensions of C. glomerata are greater than has generally been recognized. These variations can be attributed to changes in environmental conditions and events in the annual life cycle of the alga.

Cross currents : hydroelectricity and the engineering of northern Ontario

International Nuclear Information System (INIS)

Manore, J.L.

1999-01-01

The history of hydroelectric development in northern Ontario was reviewed and analysed with special emphasis on the developments along the Mattagami and Abitibi Rivers. The objective was to examine the important factors that shaped modern hydroelectric development in Canada. System builders, the privately owned Nesbitt Thomson Company, the publicly owned Hydro Electric Power Corporation of Ontario and the eventual evolution of the single power system under Ontario Hydro are chronicled. Broad historical themes such as the technological impacts, regionalism, indigenous rights, plus environmental and economic issues are examined, in addition to an appreciation of the importance of electricity in the manufacturing sector of Ontario, the impact of hydroelectric development on the northern environment and on the northern First Nations, who rely on rivers for their subsistence. Until fairly recently, government policies and interpretations of law often excluded the recognition of Aboriginal uses of river systems, thereby limiting First Nations' peoples ability to practice traditional ways of life. In essence, the book is an account of how the northeastern power system in Ontario shaped the social, political and natural environments and how the development of northeastern power sources by southern power developers shaped the regional interactions between Ontario's north and south. refs., figs

The Manitoba-Ontario intertie : perspectives of a merchant transmission developer

International Nuclear Information System (INIS)

Van Beers, R.

2006-01-01

This presentation discussed merchant transmission models for the Manitoba-Ontario intertie. Merchant transmission involves the reallocation of risk from rate payers to investors and facility users. Merchant transmission is now a niche market due to the fact that the power industry is now more centrally planned. However, merchant transmission structures limit the ability to fully assess congestion and nodal values, and governments continue to retain control of the power sector. Power generation and contracting trends are now changing as a result of market liberalization. In order to be successful, power merchants require financial markets that possess an understanding of the electricity sector. In a merchant transmission scenario, the sizing, timing, connection points, and tariffs will be determined by demonstrated commercial value, and not by central planning principles. The presentation included consideration of government block contracts and reverse block contracts. Details of the Montana-Alberta intertie project were also provided. tabs., figs

Proceedings of the Ontario Energy Association's 2004 annual conference

International Nuclear Information System (INIS)

2004-01-01

The Ontario Energy Association (OEA) is a unique trade association that represents key participants in Ontario's converging natural gas and electricity industries. Its members include energy producers, transmitters, distributors, marketers, and retailers. This conference provided a forum to discuss the role of energy policy and energy conservation in promoting competitive and efficient gas and electricity markets in Ontario. The conference featured 15 presentations, of which 3 have been catalogued separately for inclusion in this database

Marketing program for R2000 in Ontario

International Nuclear Information System (INIS)

Killins, B.L.

1990-01-01

In the Ontario new housing market, Ontario Hydro's goal is to reduce the demand for electricity, increase the utility's visibility in this market, and increase customer satisfaction. Analyses have demonstrated that it costs less to construct new houses according to R-2000 insulation standards than to install new power production and transmission facilities. Research has also shown that R-2000 houses have better air quality and energy efficiency than ordinary houses. Nevertheless, most home builders have little enthusiasm for R-2000 houses; the strictness of airtightness standards, the slowness of certification, excessive paperwork, and a lack of promised marketing support are cited as the reasons for this. Ontario Hydro and builders' associations have signed a cooperative agreement for certifying new houses with the object of self-financing the program. The program intends to see construction of 1,000 R-2000 houses in 1990. To carry out this objective, some elements have been added to Ontario Hydro's marketing program in order to make potential customers aware of the advantages of the R-2000 house. Field staff will receive rigorous training in order to prepare them for helping the diverse types of builders. A mail campaign, focusing on areas not served by natural gas where significant numbers of new houses are being built, intends to bring home builders and buyers together. In February 1990, Ontario Hydro signed agreements with four major housing manufacturers to construct a significant proportion of the R-2000 housing stock

How well suited are maar lakes of Madagascar for palaeoenvironmental multi-proxy reconstructions? - First results from shallow seismic, sedimentological and hydrological investigations in Central and Northwest Madagascar.

Science.gov (United States)

Daut, Gerhard; Jasmin Krahn, Kim; Rabhobisoa, Jean-Jacques; Ornella Moanazafy, Sergénie; Haberzettl, Torsten; Kasper, Thomas; Mäusbacher, Roland; Schwalb, Antje

2017-04-01

Madagascar is well known for its unique flora and fauna which are frequently in the focus of scientific investigations. However, studies on environmental changes in Madagascar linked to Quaternary climatic and/or anthropogenic impact are scarce. The aim of this initial study is to evaluate the potential of maar lakes, situated in different climatic zones of Madagascar, for paleoenvironmental studies and to identify promising coring sites with continuous sediment sequences reaching far back in time. Therefore, in November 2016, a shallow seismic profiling campaign, combined with surface sediment, short gravity core (max. 1.8 m), water and plankton sampling was performed on three target sites. These were two deep maar lakes, i.e., Andraikiba (Central Madagascar, 50m waterdepth) as well as Amparahibe (46,5m waterdepth) and Andampy Ambatoloaka, a shallow (5m waterdepth during low tide) former maar lake now connected to the Ocean (both NW-Madagascar. Vertical water parameter measurements in Lake Amparahibe confirm anoxic bottom conditions, while dissolved oxygen values at the water surface are about 7.9 mg/L (103%). Temperature decreases with depth from 29.3 °C to 27.2 °C, and the lake is slightly alkaline with an electrical conductivity of around 245 µS/cm. Since Andampy Ambatoloaka is connected to the ocean, it shows slightly alkaline conditions as well, electrical conductivity is high ( 57.8 mS/cm) and dissolved oxygen and temperature values are relatively stable at about 8.2 mg/L (104%) and 28.1 °C, respectively. The shallow seismic survey shows an infill with layered sediments of >50 m thickness in Lake Andraikiba. In Lake Amparahibe natural gas in the sediment prevented deeper penetration, however the record shows 10 m of undisturbed, layered sediments in the uppermost part. Sediment cores obtained from both lakes consist of dark brownish to blackish, clayey to silty and partly laminated sediments. High values of magnetic susceptibilities (>1800*10-6 SI) and

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

Science.gov (United States)

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

2009-12-01

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

A digital model for planning water management at Benton Lake National Wildlife Refuge, west-central Montana

Science.gov (United States)

Nimick, David A.; McCarthy, Peter M.; Fields, Vanessa

2011-01-01

Benton Lake National Wildlife Refuge is an important area for waterfowl production and migratory stopover in west-central Montana. Eight wetland units covering about 5,600 acres are the essential features of the refuge. Water availability for the wetland units can be uncertain owing to the large natural variations in precipitation and runoff and the high cost of pumping supplemental water. The U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, has developed a digital model for planning water management. The model can simulate strategies for water transfers among the eight wetland units and account for variability in runoff and pumped water. This report describes this digital model, which uses a water-accounting spreadsheet to track inputs and outputs to each of the wetland units of Benton Lake National Wildlife Refuge. Inputs to the model include (1) monthly values for precipitation, pumped water, runoff, and evaporation; (2) water-level/capacity data for each wetland unit; and (3) the pan-evaporation coefficient. Outputs include monthly water volume and flooded surface area for each unit for as many as 5 consecutive years. The digital model was calibrated by comparing simulated and historical measured water volumes for specific test years.

Monitoring Hydrological Patterns of Temporary Lakes Using Remote Sensing and Machine Learning Models: Case Study of La Mancha Húmeda Biosphere Reserve in Central Spain

Directory of Open Access Journals (Sweden)

Carolina Doña

2016-07-01

Full Text Available The Biosphere Reserve of La Mancha Húmeda is a wetland-rich area located in central Spain. This reserve comprises a set of temporary lakes, often saline, where water level fluctuates seasonally. Water inflows come mainly from direct precipitation and runoff of small lake watersheds. Most of these lakes lack surface outlets and behave as endorheic systems, where water withdrawal is mainly due to evaporation, causing salt accumulation in the lake beds. Remote sensing was used to estimate the temporal variation of the flooded area in these lakes and their associated hydrological patterns related to the seasonality of precipitation and evapotranspiration. Landsat 7 ETM+ satellite images for the reference period 2013–2015 were jointly used with ground-truth datasets. Several inverse modeling methods, such as two-band and multispectral indices, single-band threshold, classification methods, artificial neural network, support vector machine and genetic programming, were applied to retrieve information on the variation of the flooded areas. Results were compared to ground-truth data, and the classification errors were evaluated by means of the kappa coefficient. Comparative analyses demonstrated that the genetic programming approach yielded the best results, with a kappa value of 0.98 and a total error of omission-commission of 2%. The dependence of the variations in the water-covered area on precipitation and evaporation was also investigated. The results show the potential of the tested techniques to monitor the hydrological patterns of temporary lakes in semiarid areas, which might be useful for management strategy-linked lake conservation and specifically to accomplish the goals of both the European Water Framework Directive and the Habitats Directive.

Role of sulfate reduction in long term accumulation of organic and inorganic sulfur in lake sediments

International Nuclear Information System (INIS)

Rudd, J.W.M.; Kelly, C.A.; Furutani, A.

1986-01-01

Sulfate reduction and the accumulation of reduced sulfur in epilimnetic sediments were studied in lakes in southern Norway, the Adirondack Mountains, and at the Experimental Lakes Area (ELA) of northwestern Ontario. In all of the lakes, sulfate reduction produced substantial quantities of pyrite and organic sulfur compounds. In 9-month in situ experiments at ELA using 35 S, there was a large loss (55%) with time of the S initially reduced and deposited in the sediments and a preferential loss of inorganic S compounds which led to a predominance of organic 35 S accumulation in the sediments. An intensive study of long term accumulation of sulfur in the epilimnetic sediments of four Adirondack lakes also showed that the most important long term end product of sulfate reduction was organic S and that sulfate reduction was the major source of S to the sediments. Because of high concentrations of iron in all of the sediments samples and because of the long term storage of sulfur in sediments, mostly as organic S, iron did not limit iron sulfide accumulation in these sediments. Iron limitation is unlikely to occur except in unusual circumstances. This study indicates that formation of organic S in epilimnetic sediments is primarily responsible for H + consumption via sulfate reduction in acidified lakes

Satellite remote sensing for modeling and monitoring of water quality in the Great Lakes

Science.gov (United States)

Coffield, S. R.; Crosson, W. L.; Al-Hamdan, M. Z.; Barik, M. G.

2017-12-01

Consistent and accurate monitoring of the Great Lakes is critical for protecting the freshwater ecosystems, quantifying the impacts of climate change, understanding harmful algal blooms, and safeguarding public health for the millions who rely on the Lakes for drinking water. While ground-based monitoring is often hampered by limited sampling resolution, satellite data provide surface reflectance measurements at much more complete spatial and temporal scales. In this study, we implemented NASA data from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Aqua satellite to build robust water quality models. We developed and validated models for chlorophyll-a, nitrogen, phosphorus, and turbidity based on combinations of the six MODIS Ocean Color bands (412, 443, 488, 531, 547, and 667nm) for 2003-2016. Second, we applied these models to quantify trends in water quality through time and in relation to changing land cover, runoff, and climate for six selected coastal areas in Lakes Michigan and Erie. We found strongest models for chlorophyll-a in Lake Huron (R2 = 0.75), nitrogen in Lake Ontario (R2=0.66), phosphorus in Lake Erie (R2=0.60), and turbidity in Lake Erie (R2=0.86). These offer improvements over previous efforts to model chlorophyll-a while adding nitrogen, phosphorus, and turbidity. Mapped water quality parameters showed high spatial variability, with nitrogen concentrated largely in Superior and coastal Michigan and high turbidity, phosphorus, and chlorophyll near urban and agricultural areas of Erie. Temporal analysis also showed concurrence of high runoff or precipitation and nitrogen in Lake Michigan offshore of wetlands, suggesting that water quality in these areas is sensitive to changes in climate.

Using temporal coherence to determine the response to climate change in Boreal Shield lakes.

Science.gov (United States)

Arnott, Shelley E; Keller, Bill; Dillon, Peter J; Yan, Norman; Paterson, Michael; Findlay, David

2003-01-01

Climate change is expected to have important impacts on aquatic ecosystems. On the Boreal Shield, mean annual air temperatures are expected to increase 2 to 4 degrees C over the next 50 years. An important challenge is to predict how changes in climate and climate variability will impact natural systems so that sustainable management policies can be implemented. To predict responses to complex ecosystem changes associated with climate change, we used long-term biotic databases to evaluate how important elements of the biota in Boreal Shield lakes have responded to past fluctuations in climate. Our long-term records span a two decade period where there have been unusually cold years and unusually warm years. We used coherence analyses to test for regionally operating controls on climate, water temperature, pH, and plankton richness and abundance in three regions across Ontario: the Experimental Lakes Area, Sudbury, and Dorset. Inter-annual variation in air temperature was similar among regions, but there was a weak relationship among regions for precipitation. While air temperature was closely related to lake surface temperatures in each of the regions, there were weak relationships between lake surface temperature and richness or abundance of the plankton. However, inter-annual changes in lake chemistry (i.e., pH) were correlated with some biotic variables. In some lakes in Sudbury and Dorset, pH was dependent on extreme events. For example, El Nino related droughts resulted in acidification pulses in some lakes that influenced phytoplankton and zooplankton richness. These results suggest that there can be strong heterogeneity in lake ecosystem responses within and across regions.

Holocene climate variability in arid Central Asia as revealed from high-resolution sedimentological and geochemical analyses of laminated sediments from Lake Chatyr Kol (Central Tian Shan, Kyrgyzstan)

Science.gov (United States)

Lauterbach, S.; Plessen, B.; Dulski, P.; Mingram, J.; Prasad, S.

2013-12-01

A pronounced trend from a predominantly wet climate during the early Holocene towards significantly drier conditions since the mid-Holocene, mainly attributed to the weakening of the Asian summer monsoon (ASM), is documented in numerous palaeoclimate records from the monsoon-influenced parts of Asia, e.g. the Tibetan Plateau and north- and southeastern China. In contrast, climate in the adjacent regions of mid-latitude arid Central Asia, located north and northwest of the Tibetan Plateau, is supposed to have been characterized by pronounced dry conditions during the early Holocene, wet conditions during the mid-Holocene and a rather moderate drying during the late Holocene, which is mainly attributed to the complex interplay between the mid-latitude Westerlies and the ASM. However, although mid-latitude Central Asia thus might represent a key region for the understanding of teleconnections between the ASM system and the Westerlies, knowledge about past climate development in this region is still ambiguous due to the limited number of high-resolution palaeoclimate records. Hence, new well-dated and highly resolved palaeoclimate records from this region are expected to provide important information about spatio-temporal changes in the regional interplay between Westerlies and ASM and thus aid the understanding of global climate teleconnections. As a part of the project CADY (Central Asian Climate Dynamics), aiming at reconstructing past climatic and hydrological variability in Central Asia, a sediment core of about 6.25 m length has been recovered from alpine Lake Chatyr Kol (40°36' N, 75°14' E, 3530 m a. s. l., surface area ~170 km2, maximum depth ~20 m), located in the Central Tian Shan of Kyrgyzstan. Sediment microfacies analysis on large-scale petrographic thin sections reveals continuously sub-mm scale laminated sediments throughout the record except for the uppermost ca. 60 cm. Microsedimentological characterization of these laminae, which are most probably

Ontario's standard offer programs: moving toward a cleaner energy future

International Nuclear Information System (INIS)

Shervill, P.

2006-01-01

The Ontario Standard Offer Program is designed to ensure reliable, long-term electricity supply for Ontario. The functional areas of the program are planning, conservation and supply sector development. The long-term plan is to create a self-sustaining electricity market in Ontario with 2700 MW renewable sources by 2010 including wind, waterpower, solar photovoltaic (PV) and biomass

New rules for competition: Ontario to cap power plant emissions

International Nuclear Information System (INIS)

Anon.

1999-01-01

The Ontario government through the Dept. of the Environment announced on November 16, 1999 that it would cut the emissions from Ontario coal burning power plants that cause acid rain and smog. This announcement was a much anticipated clarification of the government's plans to clean up the power industry since the enactment of the Electricity Competition Act more than one year past. The announcement signals the beginning of a public discussion process between government and stakeholders on the environmental rules for electricity generation in Ontario. The Ontario government is expected to release draft regulations for controlling coal burning power plant emissions in the near future. Consulations with stakeholders on the regulations, as well as the rules for disclosure and labeling, are anticipated to begin in a few months. The announcement set out four principles for environmental performance in the competitive electricity market. Anti-smog requirements will be included in the stringent environmental requirements to be built into Ontario's new, competitive electricity market. The strong measures which the government will put into place when the market opens later in 2000 include: (1) regulations to cut smog and acid gas emissions for all Ontario electricity generators on the grid - these regulations will include Ontario Hydro's voluntary nitrogen oxide limits; (2) emission performance standards to define maximum acceptable emission levels for all generators wanting to sell in the Ontario market; (3) a framework to support opportunities to make greater use of more efficient, environmentally responsible technologies; and (4) disclosure requirements to ensure that electricity consumers can understand the environmental implications of their purchasing decisions

Lake-level increasing under the climate cryoaridization conditions during the Last Glacial Maximum

Science.gov (United States)

Amosov, Mikhail; Strelkov, Ivan

2017-04-01

A lake genesis and lake-level increasing during the Last Glacial Maximum (LGM) are the paramount issues in paleoclimatology. Investigating these problems reveals the regularities of lake development and figures out an arid territory conditions at the LGM stage. Pluvial theory is the most prevalent conception of lake formation during the LGM. This theory is based on a fact that the water bodies emerged and their level increased due to torrential rainfalls. In this study, it is paid attention to an alternative assumption of lake genesis at the LGM stage, which is called climate cryoaridization. In accordance with this hypothesis, the endorheic water basins had their level enlarged because of a simultaneous climate aridity and temperature decrease. In this research, a lake-level increasing in endorheic regions of Central Asia and South American Altiplano of the Andes is described. The lake investigation is related to its conditions during the LGM. The study also includes a lake catalogue clearly presenting the basin conditions at the LGM stage and nowadays. The data compilation partly consists of information from an earlier work of Mikhail Amosov, Lake-levels, Vegetation And Climate In Central Asia During The Last Glacial Maximum (EGU2014-3015). According to the investigation, a lake catalogue on 27 lakes showed that most of the water bodies had higher level. This feature could be mentioned for the biggest lakes of the Aral Sea, Lake Balkhash, Issyk-Kul etc. and for the small ones located in the mountains, such as Pamir, Tian-Shan and Tibet. Yet some lakes that are situated in Central Asian periphery (Lake Qinghai and lakes in Inner Mongolia) used to be lower than nowadays. Also, the lake-level increasing of Altiplano turned to be a significant feature during the LGM in accordance with the data of 5 lakes, such as Titicaca, Coipasa-Uyuni, Lejia, Miscanti and Santa-Maria. Most of the current endorheic basins at the LGM stage were filled with water due to abundant

Veneer-log production and receipts, North Central Region, 1976.

Science.gov (United States)

James E. Blyth; Jerold T. Hahn

1978-01-01

Shows 1976 veneer-log production and receipts by species in the Lake States (Michigan, Minnesota, and Wisconsin) and in the Central States (Illinois, Indiana, Iowa, and Missouri). Comparisons are made with similar data for 1974. Includes tables showing veneer-log production and receipts (for selected years) since 1946 in the Lake States and since 1956 in the Central...

Veneer-log production and receipts, North Central Region, 1974.

Science.gov (United States)

James E. Blyth; Jerold T. Hahn

1976-01-01

Shows 1974 veneer-log production and receipts by species in the Lake States (Michigan, Minnesota, and Wisconsin) and in the Central States (Illinois, Indiana, Iowa, and Missouri). Comparisons are made with similar data for 1972. Includes tables showing veneer-log production and receipts (for selected years) since 1946 in the Lake States and since 1956 in the Central...

Current experience with central-station nuclear cogeneration plants

International Nuclear Information System (INIS)

1981-10-01

In considering the potential of the HTGR for nuclear cogeneration, a logical element for investigation is the recent history of nuclear cogeneration experience. Little is found in recent literature; however, the twin nuclear cogeneration plant at Midland is nearing completion and this milestone will no doubt be the basis for a number of reports on the unique cogeneration facility and operating experiences with it. Less well known in the US is the Bruce Nuclear Power Development in Ontario, Canada. Originally designed to cogenerate steam for heavy water production, the Bruce facility is the focus of a major initiative to create an energy park on the shores of Lake Huron. To obtain an improved understanding of the status and implications of current nuclear cogeneration experience, GCRA representatives visited the Ontario Hydro offices in Toronto and subsequently toured the Midland site near Midland, Michigan. The primary purpose of this report is to summarize the results of those visits and to develop a series of conclusions regarding the implications for HTGR cogeneration concepts

It is just not fair: the Endangered Species Act in the United States and Ontario

Directory of Open Access Journals (Sweden)

Andrea Olive

2016-09-01

Full Text Available The United States and the Canadian province of Ontario have enacted endangered species laws that regulate private land. The rationale for this is that the vast majority of endangered species in the two countries rely on private lands for survival. However, from a landowner perspective the law is deemed unfair. This paper presents analysis from 141 interviews with landowners in three U.S. states and Ontario. In recognition of distributive justice claims, both the U.S. government and the Ontario government have enacted programs aimed at increasing financial incentives for participation and compliance with the law. However, the law is still perceived as unfair. The central argument of this paper is that future amendments and new policies for endangered species should confront two other forms of environmental justice: procedural justice and justice-as-recognition. Landowners in both countries expressed not only concerns about compensation, but also a deep desire to be included in the protection and recovery process, as well as to be recognized by government and society as good stewards of the land. The paper concludes by stating that future policy amendments need to address justice-as-recognition if endangered species conservation on private lands is to be considered fair by landowners.

Independent power and cogeneration in Ontario's new competitive electricity market

International Nuclear Information System (INIS)

Barnstable, A.G.

1999-01-01

The factors influencing the initial market pricing in the early years of Ontario's new electricity market were discussed with particular insight on the potential for near term development of independent power and cogeneration. The major factors influencing prices include: (1) no increase in retail prices, (2) financial restructuring of Ontario Hydro, (3) the Market Power Mitigation Agreement, (4) tighter power plant emissions standards, and (5) an electricity supply and demand balance. Generation competition is not expected to influence market pricing in the early years of the new electricity market. Prices will instead reflect the restructuring decisions of the Ontario government. The decision to have Ontario Power Generation Inc. (OPGI) as a single generator for Ontario Hydro's generation assets will ensure that average spot market pricing in the early market years will be close to a 3.8 c/kWh revenue cap

Ontario regulatory update

International Nuclear Information System (INIS)

Thompson, P.

1998-01-01

This paper provides a summary of recent events which when combined add up to a gradual but unmistakable movement of the energy sector in Ontario towards a fully competitive market. Some of the events precipitating this movement towards competition include the passing of the Energy Competition Act of 1998 (Bill 35), electricity deregulation, regulatory reform of the natural gas sector, and changes to the consumer protection legislation. The role of the Ontario Energy Board was also updated to bring it in line with the demands of the competitive marketplace. Among the new roles that the Board will assume are to facilitate competition, to maintain fair and reasonable rates, and to facilitate rational expansion. Another objective is to provide opportunities for including energy efficiency in government policies. Implications of the changes in the OEB's mandate for market participants were also discussed, including (1) regulated gas sales and delivery mechanisms, (2) transactional services, (3) contract restructuring, (4) consumer protection, (5) supervision of competitive market participants, and (6) market surveillance

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.

AUTOSORO: A fuel management study program for Ontario Hydro CANDU reactors

International Nuclear Information System (INIS)

Wilk, L.

1988-01-01

A computer program, AUTOSORO, has been developed to automatically simulate an Ontario Hydro CANDU reactor core for any time duration according to user-defined on-power refuelling criteria. It is a three-dimensional two-group diffusion code coupled to refuelling decision logic at three screening levels: burnup, coupled neighbor, full-core. A central feature is a projected local-iteration scheme for predicting fuelling-induced local neutron flux changes. Comparisons of AUTOSORO results with actual histories demonstrate that it will be an excellent productivity tool for future in-core fuel management studies, reducing several man-months of effort to several man-hours

A look forward to the competitive landscape of Ontario's electricity supply

International Nuclear Information System (INIS)

Carr, J.

1998-01-01

The government of Ontario is a shareholder in Ontario Hydro and is responsible for ensuring that the public receives electricity service at the lowest, most prudent price. The current monopoly arrangement provides Ontario with a revenue stream that is predictable and amenable to control. However, the emerging restructuring of Ontario's electricity supply system will be strongly dependent on the direction determined by government policy. Other factors that will have significant influence on developments will be the restructuring initiatives outside the province, and the attractiveness of the electricity sector to investors. In November 1997, Ontario released a white paper by the Minister of Energy, Science and Technology, entitled 'Direction for change'. This document is a preliminary statement of potential policy regarding electricity restructuring in Ontario. Some of the key elements of the White Paper were: (1) the creation of a competitive market in the year 2000 for both wholesale and retail customers, (2) separating monopoly operations from competitive business activities throughout the electricity sector, (3) expanding the role on the Ontario Energy Board to give it regulatory power over the electricity sector, and (4) introducing measures to ensure environmental protection. Three other relevant reports were also released in December 1997: (1) Report of the Select Committee on Ontario Hydro Nuclear Affairs, (2) Ontario Energy Board Advisory Report on Legislative Change Requirements for Natural Gas Deregulation, and (3) Report of the Toronto Transition Team. The government policy indicated by these various reports appear to represent a careful balance of many conflicting interests and obligations. According to expert observers, the emerging policy appears to have the necessary technical, financial and political support to ensure a successful competitive electricity supply system in Ontario. 4 refs

Post-glacial, land rise-induced formation and development of lakes in the Forsmark area, central Sweden

Energy Technology Data Exchange (ETDEWEB)

Brunberg, Anna-Kristina; Blomqvist, Peter [Uppsala Univ. (Sweden). Dept. of Limnology, Evolutionary Biology Centre

2000-03-15

This report describes the lakes of Uppsala county, with special emphasis on the coastal lakes in the Forsmark area. The aim of the study is to characterise different main types of lakes within the Forsmark area and to create a basis for prediction of their ontogeny, that can be used also for new lakes which due to shoreline displacement will be formed during the next 10 000 years. Areas where future research is needed to fully understand the functioning of the lake ecosystems and their ontogeny have also been identified. Three main types of lake ecosystems could be identified: The oligotrophic hardwater lakes are to a large extent surrounded by mires. Inflow as well as outflow of water is often diffuse, via the surrounding mire. The lakes are small and shallow, with nutrient poor and highly alkaline water. Three key habitats have been identified within the lakes; i) the pelagic zone, characterised by low production of biota, ii) the presumably moderately productive emergent macrophyte zone, dominated by Sphagnum and Phragmites, and iii) the light-exposed soft-bottom zone with Chara meadows and an unusually rich and presumably highly productive microbial sediment community. In later stages of the lake ontogeny, Sphagnum becomes more and more dominant in the system, which successively turns acidic. The final stage is likely to be a raised bog ecosystem with an autonomous hydrological functioning. The brown water lakes are typically found within the main part of the River Forsmarksaan and are characterised by a high flow-through of water from the upper parts of the drainage area, which are dominated by mires. Their lake water is highly stained by allochtonous organic carbon imported from the catchment area. Also in this lake type a Sphagnum-littoral successively develops, and in a mature lake three key habitats can be identified; i) the pelagic zone, most likely the dominant habitat in terms of production of organisms and in which bacterioplankton dominates the

Post-glacial, land rise-induced formation and development of lakes in the Forsmark area, central Sweden

International Nuclear Information System (INIS)

Brunberg, Anna-Kristina; Blomqvist, Peter

2000-03-01

This report describes the lakes of Uppsala county, with special emphasis on the coastal lakes in the Forsmark area. The aim of the study is to characterise different main types of lakes within the Forsmark area and to create a basis for prediction of their ontogeny, that can be used also for new lakes which due to shoreline displacement will be formed during the next 10 000 years. Areas where future research is needed to fully understand the functioning of the lake ecosystems and their ontogeny have also been identified. Three main types of lake ecosystems could be identified: The oligotrophic hardwater lakes are to a large extent surrounded by mires. Inflow as well as outflow of water is often diffuse, via the surrounding mire. The lakes are small and shallow, with nutrient poor and highly alkaline water. Three key habitats have been identified within the lakes; i) the pelagic zone, characterised by low production of biota, ii) the presumably moderately productive emergent macrophyte zone, dominated by Sphagnum and Phragmites, and iii) the light-exposed soft-bottom zone with Chara meadows and an unusually rich and presumably highly productive microbial sediment community. In later stages of the lake ontogeny, Sphagnum becomes more and more dominant in the system, which successively turns acidic. The final stage is likely to be a raised bog ecosystem with an autonomous hydrological functioning. The brown water lakes are typically found within the main part of the River Forsmarksaan and are characterised by a high flow-through of water from the upper parts of the drainage area, which are dominated by mires. Their lake water is highly stained by allochtonous organic carbon imported from the catchment area. Also in this lake type a Sphagnum-littoral successively develops, and in a mature lake three key habitats can be identified; i) the pelagic zone, most likely the dominant habitat in terms of production of organisms and in which bacterioplankton dominates the

Overview of surgery for oral cavity cancer in Ontario.

Science.gov (United States)

Eskander, Antoine; Irish, Jonathan; Gullane, Patrick; Gilbert, Ralph; de Almeida, John R; Freeman, Jeremy; Giuliani, Meredith; Urbach, David R; Goldstein, David P

2016-07-01

The pupose of this study was to describe variations in incidence and resection rates of patients with oral cavity squamous cell carcinoma (SCC) in Ontario. All oral cavity SCCs in Ontario between 2003 and 2010 were identified from the Ontario Cancer Registry. Incidence and resection rates along with variations in care were compared by sociodemographic factors and Ontario health regions. The 8-year incidence rates for oral cavity SCC was 21.3 per 100,000 with variations by sex, age group, neighborhood income, and community size. Seventy-four percent of patients underwent an oral cavity cancer resection, of which 91% were at a regional head and neck cancer center. Variations in resection rates existed by region of residence and treatment. Oral cavity cancer incidence rates vary by sex, age, neighborhood income, community size, and health region. Resection rates vary by age and health region. Oral cavity cancer care is highly regionalized in Ontario. © 2015 Wiley Periodicals, Inc. Head Neck 38: 1113-1118, 2016. © 2015 Wiley Periodicals, Inc.

The economics of age-group swimming in Ontario.

Science.gov (United States)

Eynon, R B; Kitchen, P D; Semotiuk, D M

1980-09-01

This study investigated the socio-economic status of the parents of Ontario swimmers and parental expenditures, in terms of time and money, in support of competitive swimming. Questionnaires were mailed to a sample of 400 families of Ontario competitive swimmers. Spearman rho analyses were used to determine the relationships of membership fee, total cost and total time spent by the parents to the ability and age of the swimmer and the number of hours of practice and swim meets. Parents of Ontario competitive swimmers are upper middle class and devote a great deal of their time (X = 433 hours) and money (X = $744.00) annually to competitive swimming. Total expenditures and time spend by the parents were greater for those children were young and also for those whose children demonstrated greater ability (i.e., closer to Ontario record). Spearman rho analyses suggested that membership fees are not determined on the basis of age, number of practice hours or number of swim meets.

Comments on cladocerans of crater lakes of the Nevado de Toluca Volcano (Central Mexico), with the description of a new species, Alona manueli sp. nov.

Science.gov (United States)

Sinev, Artem Y; Zawisza, Edyta

2013-01-01

Cladoceran communities of two lakes of Nevado de Toluca Volcano, Central Mexico, were studied. A new species of Aloninae, Alona manueli sp. nov., is described. It was previously confused with Palearctic Alona intermedia Sars, 1862, but clearly differs from it in the morphology of postabdomen, head shield and head pores, and thoracic limbs. Position of Alona manueli sp. nov. within the genus is unclear, it did not belong to any species-group within Alona s. lato. Other species recorded in the studied lakes are Alona ossiani Sinev, 1998, Alonella pulchella Herrick, 1884, Chydorus belonging to sphaericus-group, Eurycercus longirostris Hann, 1982 and Pleuroxus cf. denticulatus Birge, 1879.

Tectonic implications of seismic activity recorded by the northern Ontario seismograph network

International Nuclear Information System (INIS)

Wetmiller, R.J.; Cajka, M.G.

1989-01-01

The northern Ontario seismograph network, which has operated under the Canadian Nuclear Fuel Waste Management Program since 1982, has provided valuable data to supplement those recorded by the Canadian national networks on earthquake activity, rockburst activity, the distribution of regional seismic velocities, and the contemporary stress field in northern Ontario. The combined networks recorded the largest earthquake known in northwestern Ontario, M 3.9 near Sioux Lookout on February 11, 1984, and many smaller earthquakes in northeastern Ontario. Focal mechanism solutions of these and older events showed high horizontal stress and thrust faulting to be dominant features of the contemporary tectonics of northern Ontario. The zone of more intense earthquake activity in western Quebec appeared to extend northwestward into the Kapuskasing area of northeastern Ontario, where an area of persistent microearthquake activity had been identified by a seismograph station near Kapuskasing. Controlled explosions of the 1984 Kapuskasing Uplift seismic profile experiment recorded on the northern Ontario seismograph network showed the presence of anomalously high LG velocities in northeastern Ontario (3.65 km/s) that when properly taken into account reduced the mislocation errors of well-recorded seismic events by 50% on average

Ontario Hydro looks at security

International Nuclear Information System (INIS)

Green, B.J.; Kee, B.

1995-01-01

Ontario Hydro operates 20 CANDU reactors on three different sites. Since 1984, a review of security arrangements on all the sites has taken place on a five-yearly basis. The review process for 1995 is outlined. The three objectives were as follows: to assess current security threats and risks to the stations; to assess the adequacy of the existing programme to protect against current threats; by comparing the security programme against those of comparable entities to establish benchmarks for good practice as a basis for improvements at Ontario Hydro. Valuable insights gained through the review are listed. These could be useful to other utilities. (UK)

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

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

Current issues in the management of low- and intermediate-level radioactive wastes from Ontario Hydro's CANDU reactors

International Nuclear Information System (INIS)

Krasznai, J.P.; Vaughan, B.R.; Williamson, A.S.

1990-01-01

Nuclear generating stations (NGSs) in Canada are operated by utilities in Ontario, Quebec, and New Brunswick. Ontario Hydro, with a committed nuclear program of 13,600 MW(electric) is the major producer of CANDU pressurized heavy-water reactor (PHWR) low- and intermediate-level radioactive wastes. All radioactive wastes with the exception of irradiated fuel are processed and retrievably stored at a centralized facility at the Bruce Nuclear Power Development site. Solid-waste classifications and annual production levels are given. Solid-waste management practices at the site as well as the physical, chemical, and radiochemical characteristics of the wastes are well documented. The paper summarizes types, current inventory, and estimated annual production rate of liquid waste. Operation of the tritium recovery facility at Darlington NGS, which removes tritium from heavy water and produces tritium gas in the process, gives rise to secondary streams of tritiated solid and liquid wastes, which will receive special treatment and packaging. In addition to the treatment of radioactive liquid wastes, there are a number of other important issues in low- and intermediate-level radioactive waste management that Ontario Hydro will be addressing over the next few years. The most pressing of these is the reduction of radioactive wastes through in-station material control, employee awareness, and improved waste characterization and segregation programs. Since Ontario Hydro intends to store retrievable wastes for > 50 yr, it is necessary to determine the behavior of wastes under long-term storage conditions