Great Lakes rivermouths: a primer for managers

Science.gov (United States)

Pebbles, Victoria; Larson, James; Seelbach, Paul; Pebbles, Victoria; Larson, James; Seelbach, Paul

2013-01-01

Between the North American Great Lakes and their tributaries are the places where the confluence of river and lake waters creates a distinct ecosystem: the rivermouth ecosystem. Human development has often centered around these rivermouths, in part, because they provide a rich array of ecosystem services. Not surprisingly, centuries of intense human activity have led to substantial pressures on, and alterations to, these ecosystems, often diminishing or degrading their ecological functions and associated ecological services. Many Great Lakes rivermouths are the focus of intense restoration efforts. For example, 36 of the active Great Lakes Areas of Concern (AOCs) are rivermouths or areas that include one or more rivermouths. Historically, research of rivermouth ecosystems has been piecemeal, focused on the Great Lakes proper or on the upper reaches of tributaries, with little direct study of the rivermouth itself. Researchers have been divided among disciplines, agencies and institutions; and they often work independently and use disparate venues to communicate their work. Management has also been fragmented with a focus on smaller, localized, sub-habitat units and socio-political or economic elements, rather than system-level consideration. This Primer presents the case for a more holistic approach to rivermouth science and management that can enable restoration of ecosystem services with multiple benefits to humans and the Great Lakes ecosystem. A conceptual model is presented with supporting text that describes the structures and processes common to all rivermouths, substantiating the case for treating these ecosystems as an identifiable class.1 Ecological services provided by rivermouths and changes in how humans value those services over time are illustrated through case studies of two Great Lakes rivermouths—the St. Louis River and the Maumee River. Specific ecosystem services are identified in italics throughout this Primer and follow definitions described

Key Lake human resources and northern business initiative

International Nuclear Information System (INIS)

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

1994-01-01

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

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

Science.gov (United States)

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

2000-01-01

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

Energy and water in the Great Lakes.

Energy Technology Data Exchange (ETDEWEB)

Tidwell, Vincent Carroll

2011-11-01

The nexus between thermoelectric power production and water use is not uniform across the U.S., but rather differs according to regional physiography, demography, power plant fleet composition, and the transmission network. That is, in some regions water demand for thermoelectric production is relatively small while in other regions it represents the dominate use. The later is the case for the Great Lakes region, which has important implications for the water resources and aquatic ecology of the Great Lakes watershed. This is today, but what about the future? Projected demographic trends, shifting lifestyles, and economic growth coupled with the threat of global climate change and mounting pressure for greater U.S. energy security could have profound effects on the region's energy future. Planning for such an uncertain future is further complicated by the fact that energy and environmental planning and regulatory decisionmaking is largely bifurcated in the region, with environmental and water resource concerns generally taken into account after new energy facilities and technologies have been proposed, or practices are already in place. Based on these confounding needs, the objective of this effort is to develop Great Lakes-specific methods and tools to integrate energy and water resource planning and thereby support the dual goals of smarter energy planning and development, and protection of Great Lakes water resources. Guiding policies for this planning are the Great Lakes and St. Lawrence River Basin Water Resources Compact and the Great Lakes Water Quality Agreement. The desired outcome of integrated energy-water-aquatic resource planning is a more sustainable regional energy mix for the Great Lakes basin ecosystem.

Estimating Spring Condensation on the Great Lakes

Science.gov (United States)

Meyer, A.; Welp, L.

2017-12-01

The Laurentian Great Lakes region provides opportunities for shipping, recreation, and consumptive water use to a large part of the United States and Canada. Water levels in the lakes fluctuate yearly, but attempts to model the system are inadequate because the water and energy budgets are still not fully understood. For example, water levels in the Great Lakes experienced a 15-year low period ending in 2013, the recovery of which has been attributed partially to decreased evaporation and increased precipitation and runoff. Unlike precipitation, the exchange of water vapor between the lake and the atmosphere through evaporation or condensation is difficult to measure directly. However, estimates have been constructed using off-shore eddy covariance direct measurements of latent heat fluxes, remote sensing observations, and a small network of monitoring buoys. When the lake surface temperature is colder than air temperature as it is in spring, condensation is larger than evaporation. This is a relatively small component of the net annual water budget of the lakes, but the total amount of condensation may be important for seasonal energy fluxes and atmospheric deposition of pollutants and nutrients to the lakes. Seasonal energy fluxes determine, and are influenced by, ice cover, water and air temperatures, and evaporation in the Great Lakes. We aim to quantify the amount of spring condensation on the Great Lakes using the National Center for Atmospheric Prediction North American Regional Reanalysis (NCEP NARR) Data for Winter 2013 to Spring 2017 and compare the condensation values of spring seasons following high volume, high duration and low volume, low duration ice cover.

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.

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.

Long-Term Variability of Satellite Lake Surface Water Temperatures in the Great Lakes

Science.gov (United States)

Gierach, M. M.; Matsumoto, K.; Holt, B.; McKinney, P. J.; Tokos, K.

2014-12-01

The Great Lakes are the largest group of freshwater lakes on Earth that approximately 37 million people depend upon for fresh drinking water, food, flood and drought mitigation, and natural resources that support industry, jobs, shipping and tourism. Recent reports have stated (e.g., the National Climate Assessment) that climate change can impact and exacerbate a range of risks to the Great Lakes, including changes in the range and distribution of certain fish species, increased invasive species and harmful algal blooms, declining beach health, and lengthened commercial navigation season. In this study, we will examine the impact of climate change on the Laurentian Great Lakes through investigation of long-term lake surface water temperatures (LSWT). We will use the ATSR Reprocessing for Climate: Lake Surface Water Temperature & Ice Cover (ARC-Lake) product over the period 1995-2012 to investigate individual and interlake variability. Specifically, we will quantify the seasonal amplitude of LSWTs, the first and last appearances of the 4°C isotherm (i.e., an important identifier of the seasonal evolution of the lakes denoting winter and summer stratification), and interpret these quantities in the context of global interannual climate variability such as ENSO.

78 FR 5474 - Great Lakes Pilotage Advisory Committee

Science.gov (United States)

2013-01-25

... DEPARTMENT OF HOMELAND SECURITY Coast Guard [USCG-2013-0029] Great Lakes Pilotage Advisory... Meeting. SUMMARY: The Great Lakes Pilotage Advisory Committee (GLPAC) will meet on February 11, 2013, in..., 2013, after the committee completes its work on the agenda given under SUPPLEMENTARY INFORMATION...

Evaluate prevailing climate change on Great Lakes water levels

International Nuclear Information System (INIS)

Islam, M.

2009-01-01

'Full text:'In this paper, results of a comprehensive water mass balance modeling for the Great Lakes against prevailing and different anticipated climate change scenarios would be presented. Modeling is done in evaluating the changes in the lake storages and then changes in the lake's water level considering present condition, uncertainty and variability of climate and hydrologic conditions in the future. Inflow-outflow and consequent changes in the five Great Lake's storages are simulated for the last 30 years and then projected to evaluate the changes in the lake storages for the next 50 years. From the predicted changes in the lake storage data, water level is calculated using mass to linear conversion equation. Modeling and analysis results are expected to be helpful in understanding the possible impacts of the climate change on the Great Lakes water environment and preparing strategic plan for the sustainable management of lake's water resources. From the recent past, it is observed that there is a depleting trend in the lakes water level and hence there is a potential threat to lake's water environment and uncertainty of the availability of quality and quantity of water for the future generations, especially against prevailing and anticipated climate changes. For this reason, it is an urgent issue of understanding and quantifying the potential impacts of climate change on the Great Lake's water levels and storages. (author)

Great Lakes Environmental Research Laboratory

Data.gov (United States)

Federal Laboratory Consortium — NOAA-GLERL and its partners conduct innovative research on the dynamic environments and ecosystems of the Great Lakes and coastal regions to provide information for...

Great Lakes CoastWatch Node

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — CoastWatch is a nationwide National Oceanic and Atmospheric Administration (NOAA) program within which the Great Lakes Environmental Research Laboratory (GLERL)...

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

Science.gov (United States)

Xiao, C.; Lofgren, B. M.

2014-12-01

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

Early emergence of anthropogenically forced heat waves in the western United States and Great Lakes

Science.gov (United States)

Lopez, Hosmay; West, Robert; Dong, Shenfu; Goni, Gustavo; Kirtman, Ben; Lee, Sang-Ki; Atlas, Robert

2018-05-01

Climate projections for the twenty-first century suggest an increase in the occurrence of heat waves. However, the time at which externally forced signals of anthropogenic climate change (ACC) emerge against background natural variability (time of emergence (ToE)) has been challenging to quantify, which makes future heat-wave projections uncertain. Here we combine observations and model simulations under present and future forcing to assess how internal variability and ACC modulate US heat waves. We show that ACC dominates heat-wave occurrence over the western United States and Great Lakes regions, with ToE that occurred as early as the 2020s and 2030s, respectively. In contrast, internal variability governs heat waves in the northern and southern Great Plains, where ToE occurs in the 2050s and 2070s; this later ToE is believed to be a result of a projected increase in circulation variability, namely the Great Plain low-level jet. Thus, greater mitigation and adaptation efforts are needed in the Great Lakes and western United States regions.

46 CFR 30.10-33 - Great Lakes-TB/L.

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Great Lakes-TB/L. 30.10-33 Section 30.10-33 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS GENERAL PROVISIONS Definitions § 30.10-33 Great Lakes—TB/L. Under this designation shall be included all tank vessels navigating the Great Lakes. ...

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.

Trends in fishery management of the Great Lakes

Science.gov (United States)

Smith, Stanford H.

1970-01-01

Some hope is returning for recovery of the fish stocks of the Great Lakes, which have been outstanding examples of abuse although they are the world's largest and most valuable freshwater fishery resource. The lakes and the fish in them have been under complete jurisdiction of sovereign nations and their subdivisions almost since the settlement of north-central North America, but ironically this control has not prevented their decadence. For the first time in the long history of the Great Lakes fishery, management measures have been taken to meliorate conditions that contributed to earlier difficulties.

Great Lakes rivermouth ecosystems: scientific synthesis and management implications

Science.gov (United States)

Larson, James H.; Trebitz, Anett S.; Steinman, Alan D.; Wiley, Michael J.; Carlson Mazur, Martha; Pebbles, Victoria; Braun, Heather A.; Seelbach, Paul W.

2013-01-01

At the interface of the Great Lakes and their tributary rivers lies the rivermouths, a class of aquatic ecosystem where lake and lotic processes mix and distinct features emerge. Many rivermouths are the focal point of both human interaction with the Great Lakes and human impacts to the lakes; many cities, ports, and beaches are located in rivermouth ecosystems, and these human pressures often degrade key ecological functions that rivermouths provide. Despite their ecological uniqueness and apparent economic importance, there has been relatively little research on these ecosystems as a class relative to studies on upstream rivers or the open-lake waters. Here we present a synthesis of current knowledge about ecosystem structure and function in Great Lakes rivermouths based on studies in both Laurentian rivermouths, coastal wetlands, and marine estuarine systems. A conceptual model is presented that establishes a common semantic framework for discussing the characteristic spatial features of rivermouths. This model then is used to conceptually link ecosystem structure and function to ecological services provided by rivermouths. This synthesis helps identify the critical gaps in understanding rivermouth ecology. Specifically, additional information is needed on how rivermouths collectively influence the Great Lakes ecosystem, how human alterations influence rivermouth functions, and how ecosystem services provided by rivermouths can be managed to benefit the surrounding socioeconomic networks.

Landsat-based trend analysis of lake dynamics across northern permafrost regions

Science.gov (United States)

Nitze, Ingmar; Grosse, Guido; Jones, Benjamin M.; Arp, Christopher D.; Ulrich, Mathias; Federov, Alexander; Veremeeva, Alexandra

2017-01-01

Lakes are a ubiquitous landscape feature in northern permafrost regions. They have a strong impact on carbon, energy and water fluxes and can be quite responsive to climate change. The monitoring of lake change in northern high latitudes, at a sufficiently accurate spatial and temporal resolution, is crucial for understanding the underlying processes driving lake change. To date, lake change studies in permafrost regions were based on a variety of different sources, image acquisition periods and single snapshots, and localized analysis, which hinders the comparison of different regions. Here we present, a methodology based on machine-learning based classification of robust trends of multi-spectral indices of Landsat data (TM,ETM+, OLI) and object-based lake detection, to analyze and compare the individual, local and regional lake dynamics of four different study sites (Alaska North Slope, Western Alaska, Central Yakutia, Kolyma Lowland) in the northern permafrost zone from 1999 to 2014. Regional patterns of lake area change on the Alaska North Slope (-0.69%), Western Alaska (-2.82%), and Kolyma Lowland (-0.51%) largely include increases due to thermokarst lake expansion, but more dominant lake area losses due to catastrophic lake drainage events. In contrast, Central Yakutia showed a remarkable increase in lake area of 48.48%, likely resulting from warmer and wetter climate conditions over the latter half of the study period. Within all study regions, variability in lake dynamics was associated with differences in permafrost characteristics, landscape position (i.e. upland vs. lowland), and surface geology. With the global availability of Landsat data and a consistent methodology for processing the input data derived from robust trends of multi-spectral indices, we demonstrate a transferability, scalability and consistency of lake change analysis within the northern permafrost region.

GLERL Great Lakes Air Temperature/Degree Day Climatology, 1897-1983

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Daily maximum and minimum temperatures for 25 stations around the Great Lakes, 1897 to 1983, were given to NSIDC by the NOAA Great Lakes Environmental Research...

From top to bottom: Do Lake Trout diversify along a depth gradient in Great Bear Lake, NT, Canada?

Science.gov (United States)

Chavarie, Louise; Howland, Kimberly L; Harris, Les N; Hansen, Michael J; Harford, William J; Gallagher, Colin P; Baillie, Shauna M; Malley, Brendan; Tonn, William M; Muir, Andrew M; Krueger, Charles C

2018-01-01

Depth is usually considered the main driver of Lake Trout intraspecific diversity across lakes in North America. Given that Great Bear Lake is one of the largest and deepest freshwater systems in North America, we predicted that Lake Trout intraspecific diversity to be organized along a depth axis within this system. Thus, we investigated whether a deep-water morph of Lake Trout co-existed with four shallow-water morphs previously described in Great Bear Lake. Morphology, neutral genetic variation, isotopic niches, and life-history traits of Lake Trout across depths (0-150 m) were compared among morphs. Due to the propensity of Lake Trout with high levels of morphological diversity to occupy multiple habitat niches, a novel multivariate grouping method using a suite of composite variables was applied in addition to two other commonly used grouping methods to classify individuals. Depth alone did not explain Lake Trout diversity in Great Bear Lake; a distinct fifth deep-water morph was not found. Rather, Lake Trout diversity followed an ecological continuum, with some evidence for adaptation to local conditions in deep-water habitat. Overall, trout caught from deep-water showed low levels of genetic and phenotypic differentiation from shallow-water trout, and displayed higher lipid content (C:N ratio) and occupied a higher trophic level that suggested an potential increase of piscivory (including cannibalism) than the previously described four morphs. Why phenotypic divergence between shallow- and deep-water Lake Trout was low is unknown, especially when the potential for phenotypic variation should be high in deep and large Great Bear Lake. Given that variation in complexity of freshwater environments has dramatic consequences for divergence, variation in the complexity in Great Bear Lake (i.e., shallow being more complex than deep), may explain the observed dichotomy in the expression of intraspecific phenotypic diversity between shallow- vs. deep-water habitats

From top to bottom: Do Lake Trout diversify along a depth gradient in Great Bear Lake, NT, Canada?

Science.gov (United States)

Chavarie, Louise; Howland, Kimberly L.; Harris, Les N.; Hansen, Michael J.; Harford, William J.; Gallagher, Colin P.; Baillie, Shauna M.; Malley, Brendan; Tonn, William M.; Muir, Andrew M.; Krueger, Charles C.

2018-01-01

Depth is usually considered the main driver of Lake Trout intraspecific diversity across lakes in North America. Given that Great Bear Lake is one of the largest and deepest freshwater systems in North America, we predicted that Lake Trout intraspecific diversity to be organized along a depth axis within this system. Thus, we investigated whether a deep-water morph of Lake Trout co-existed with four shallow-water morphs previously described in Great Bear Lake. Morphology, neutral genetic variation, isotopic niches, and life-history traits of Lake Trout across depths (0–150 m) were compared among morphs. Due to the propensity of Lake Trout with high levels of morphological diversity to occupy multiple habitat niches, a novel multivariate grouping method using a suite of composite variables was applied in addition to two other commonly used grouping methods to classify individuals. Depth alone did not explain Lake Trout diversity in Great Bear Lake; a distinct fifth deep-water morph was not found. Rather, Lake Trout diversity followed an ecological continuum, with some evidence for adaptation to local conditions in deep-water habitat. Overall, trout caught from deep-water showed low levels of genetic and phenotypic differentiation from shallow-water trout, and displayed higher lipid content (C:N ratio) and occupied a higher trophic level that suggested an potential increase of piscivory (including cannibalism) than the previously described four morphs. Why phenotypic divergence between shallow- and deep-water Lake Trout was low is unknown, especially when the potential for phenotypic variation should be high in deep and large Great Bear Lake. Given that variation in complexity of freshwater environments has dramatic consequences for divergence, variation in the complexity in Great Bear Lake (i.e., shallow being more complex than deep), may explain the observed dichotomy in the expression of intraspecific phenotypic diversity between shallow- vs. deep-water habitats

Environmental conditions synchronize waterbird mortality events in the Great Lakes

Science.gov (United States)

Prince, Karine; Chipault, Jennifer G.; White, C. LeAnn; Zuckerberg, Benjamin

2018-01-01

Since the 1960s, periodic outbreaks of avian botulism type E have contributed to large-scale die-offs of thousands of waterbirds throughout the Great Lakes of the United States. In recent years, these events have become more common and widespread. Occurring during the summer and autumn months, the prevalence of these die-offs varies across years and is often associated with years of warmer lake temperatures and lower water levels. Little information exists on how environmental conditions mediate the spatial and temporal characteristics of mortality events.In 2010, a citizen science programme, Avian Monitoring for Botulism Lakeshore Events (AMBLE), was launched to enhance surveillance efforts and detect the appearance of beached waterbird carcasses associated with avian botulism type E outbreaks in northern Lake Michigan. Using these data, our goal was to quantify the within-year characteristics of mortality events for multiple species, and to test whether the synchrony of these events corresponded to fluctuations in two environmental factors suspected to be important in the spread of avian botulism: water temperature and the prevalence of green macroalgae.During two separate events of mass waterbird mortality, we found that the detection of bird carcasses was spatially synchronized at scales of c. 40 km. Notably, the extent of this spatial synchrony in avian mortality matched that of fluctuations in lake surface water temperatures and the prevalence of green macroalgae.Synthesis and applications. Our findings are suggestive of a synchronizing effect where warmer lake temperatures and the appearance of macroalgae mediate the characteristics of avian mortality. In future years, rising lake temperatures and a higher propensity of algal masses could lead to increases in the magnitude and synchronization of avian mortality due to botulism. We advocate that citizen-based monitoring efforts are critical for identifying the potential environmental conditions associated

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.

Wildlife in the Upper Great Lakes Region: a community profile.

Science.gov (United States)

Janine M. Benyus; Richard R. Buech; Mark D. Nelson

1992-01-01

Wildlife habitat data from seven Great Lakes National Forests were combined into a wildlife-habitat matrix named NORTHWOODS. The composite NORTHWOODS data base is summarized. Multiple queries of NORTHWOODS were used to profile the wildlife community of the Upper Great Lakes region.

Observing a catastrophic thermokarst lake drainage in northern Alaska

Science.gov (United States)

Jones, Benjamin M.; Arp, Christopher D.

2015-01-01

The formation and drainage of thermokarst lakes have reshaped ice-rich permafrost lowlands in the Arctic throughout the Holocene. North of Teshekpuk Lake, on the Arctic Coastal Plain of northern Alaska, thermokarst lakes presently occupy 22.5% of the landscape, and drained thermokarst lake basins occupy 61.8%. Analysis of remotely sensed imagery indicates that nine lakes (>10 ha) have drained in the 1,750 km2 study area between 1955 and 2014. The most recent lake drainage was observed using in situ data loggers providing information on the duration and magnitude of the event, and a nearby weather station provided information on the environmental conditions preceding the lake drainage. Lake 195 (L195), an 80 ha thermokarst lake with an estimated water volume of ~872,000 m3, catastrophically drained on 05 July 2014. Abundant winter snowfall and heavy early summer precipitation resulted in elevated lake water levels that likely promoted bank overtopping, thermo-erosion along an ice-wedge network, and formation of a 9 m wide, 2 m deep, and 70 m long drainage gully. The lake emptied in 36 hours, with 75% of the water volume loss occurring in the first ten hours. The observed peak discharge of the resultant flood was 25 m3/s, which is similar to that in northern Alaska river basins whose areas are more than two orders of magnitude larger. Our findings support the catastrophic nature of sudden lake drainage events and the mechanistic hypotheses developed by J. Ross Mackay.

46 CFR 11.430 - Endorsements for the Great Lakes and inland waters.

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Endorsements for the Great Lakes and inland waters. 11... Endorsements for the Great Lakes and inland waters. Any license or MMC endorsement issued for service on the Great Lakes and inland waters is valid on all of the inland waters of the United States as defined in...

Predicting Great Lakes fish yields: tools and constraints

Science.gov (United States)

Lewis, C.A.; Schupp, D.H.; Taylor, W.W.; Collins, J.J.; Hatch, Richard W.

1987-01-01

Prediction of yield is a critical component of fisheries management. The development of sound yield prediction methodology and the application of the results of yield prediction are central to the evolution of strategies to achieve stated goals for Great Lakes fisheries and to the measurement of progress toward those goals. Despite general availability of species yield models, yield prediction for many Great Lakes fisheries has been poor due to the instability of the fish communities and the inadequacy of available data. A host of biological, institutional, and societal factors constrain both the development of sound predictions and their application to management. Improved predictive capability requires increased stability of Great Lakes fisheries through rehabilitation of well-integrated communities, improvement of data collection, data standardization and information-sharing mechanisms, and further development of the methodology for yield prediction. Most important is the creation of a better-informed public that will in turn establish the political will to do what is required.

78 FR 21937 - Proposed Agency Information Collection Request: Comment Request; Great Lakes Accountability...

Science.gov (United States)

2013-04-12

... Collection Request: Comment Request; Great Lakes Accountability System (Renewal) AGENCY: Environmental... an information collection request (ICR), ``Great Lakes Accountability System'' (EPA ICR No. 2379.02... using www.regulations.gov (our preferred method) or by mail to: Great Lakes Accountability System, Attn...

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

Science.gov (United States)

2010-06-17

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

Evaluation of Sugar Maple Dieback in the Upper Great Lakes Region and Development of a Forest Health Youth Education Program

Science.gov (United States)

Bal, Tara L.

2013-01-01

Sugar Maple, "Acer saccharum" Marsh., is one of the most valuable trees in the northern hardwood forests. Severe dieback was recently reported by area foresters in the western Upper Great Lakes Region. Sugar Maple has had a history of dieback over the last 100 years throughout its range and different variables have been identified as…

The Great Lakes Spill Co-op and how it works

International Nuclear Information System (INIS)

Usher, D.

1994-01-01

A major program was launched by spill control professionals and industry in 1990 when it created the Great Lakes Spill Cooperative (GLSCOOP). The major objective of this cooperative is to provide a network to facilitate quick response in crises situations in the Great Lakes region. Specifically, the Great Lakes Spill Cooperative will: (1) coordinate environmental response activities in connection with emergency conditions as a result of spills of petroleum and hazardous substances in the Great Lakes; (2) apply state-of-the-art management, training and equipment technology during emergency environmental response operations, consistent with local, state and federal regulations; and (3) promote cooperation with its members, governmental agencies as well as allied trade and professional associations, consistent with the existing laws, in mobilizing equipment and expertise in controlling or mitigating pollution incidents in the Great Lakes. In this presentation the author discusses how the cooperative was formed, how it will operate, the members of the group and their individual roles as well as the organization's partnership with government--local, state and federal. He also discusses his involvement in the formation of the Mamne Response Alliance (MRA). This co-op was utilized recently by one of its members to provide 100 personnel who were Haz-Woper trained for the recent Tampa Bay Spill in August of last year

Ecosystem services in the Great Lakes

Science.gov (United States)

A comprehensive inventory of ecosystem services across the entire Great Lakes basin is currently lacking and is needed to make informed management decisions. A greater appreciation and understanding of ecosystem services, including both use and non-use services, may have avoided ...

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.

Great Lakes Energy Institute

Energy Technology Data Exchange (ETDEWEB)

Alexander, J. Iwan [Case Western Reserve Univ., Cleveland, OH (United States)

2012-11-18

The vision of the Great Lakes Energy Institute is to enable the transition to advanced, sustainable energy generation, storage, distribution and utilization through coordinated research, development, and education. The Institute will place emphasis on translating leading edge research into next generation energy technology. The Institute’s research thrusts focus on coordinated research in decentralized power generation devices (e.g. fuel cells, wind turbines, solar photovoltaic devices), management of electrical power transmission and distribution, energy storage, and energy efficiency.

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.

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

Science.gov (United States)

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

2014-01-01

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

Temperature variations in the southern Great Lakes during the last deglaciation: Comparison between pollen and GDGT proxies

Science.gov (United States)

Watson, Benjamin I.; Williams, John W.; Russell, James M.; Jackson, Stephen T.; Shane, Linda; Lowell, Thomas V.

2018-02-01

Our understanding of deglacial climate history in the southern Great Lakes region of the United States is primarily based upon fossil pollen data, with few independent and multi-proxy climate reconstructions. Here we introduce a new, well-dated fossil pollen record from Stotzel-Leis, OH, and a new deglacial temperature record based on branched glycerol dialkyl glycerol tetraethers (brGDGTs) at Silver Lake, OH. We compare these new data to previously published records and to a regional stack of pollen-based temperature reconstructions from Stotzel-Leis, Silver Lake, and three other well-dated sites. The new and previously published pollen records at Stotzel-Leis are similar, but our new age model brings vegetation events into closer alignment with known climatic events such as the Younger Dryas (YD). brGDGT-inferred temperatures correlate strongly with pollen-based regional temperature reconstructions, with the strongest correlation obtained for a global soil-based brGDGT calibration (r2 = 0.88), lending confidence to the deglacial reconstructions and the use of brGDGT and regional pollen stacks as paleotemperature proxies in eastern North America. However, individual pollen records show large differences in timing, rates, and amplitudes of inferred temperature change, indicating caution with paleoclimatic inferences based on single-site pollen records. From 16.0 to 10.0ka, both proxies indicate that regional temperatures rose by ∼10 °C, roughly double the ∼5 °C estimates for the Northern Hemisphere reported in prior syntheses. Change-point analysis of the pollen stack shows accelerated warming at 14.0 ± 1.2ka, cooling at 12.6 ± 0.4ka, and warming from 11.6 ± 0.5ka into the Holocene. The timing of Bølling-Allerød (B-A) warming and YD onset in our records lag by ∼300-500 years those reported in syntheses of temperature records from the northern mid-latitudes. This discrepancy is too large to be attributed to uncertainties in radiocarbon dating, and

Distribution of an invasive aquatic pathogen (viral hemorrhagic septicemia virus) in the Great Lakes and its relationship to shipping

Science.gov (United States)

Bain, Mark B.; Cornwell, Emily R.; Hope, Kristine M.; Eckerlin, Geofrey E.; Casey, Rufina N.; Groocock, Geoffrey H.; Getchell, Rodman G.; Bowser, Paul R.; Winton, James R.; Batts, William N.; Cangelosi, Allegra; Casey, James W.

2010-01-01

Viral hemorrhagic septicemia virus (VHSV) is a rhabdovirus found in fish from oceans of the northern hemisphere and freshwaters of Europe. It has caused extensive losses of cultured and wild fish and has become established in the North American Great Lakes. Large die-offs of wild fish in the Great Lakes due to VHSV have alarmed the public and provoked government attention on the introduction and spread of aquatic animal pathogens in freshwaters. We investigated the relations between VHSV dispersion and shipping and boating activity in the Great Lakes by sampling fish and water at sites that were commercial shipping harbors, recreational boating centers, and open shorelines. Fish and water samples were individually analyzed for VHSV using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and cell culture assays. Of 1,221 fish of 17 species, 55 were VHSV positive with highly varied qRT-PCR titers (1 to 5,950,000 N gene copies). The detections of VHSV in fish and water samples were closely associated and the virus was detected in 21 of 30 sites sampled. The occurrence of VHSV was not related to type of site or shipping related invasion hotspots. Our results indicate that VHSV is widely dispersed in the Great Lakes and is both an enzootic and epizootic pathogen. We demonstrate that pathogen distribution information could be developed quickly and is clearly needed for aquatic ecosystem conservation, management of affected populations, and informed regulation of the worldwide trade of aquatic organisms.

Methane bubbling from northern lakes: present and future contributions to the global methane budget.

Science.gov (United States)

Walter, Katey M; Smith, Laurence C; Chapin, F Stuart

2007-07-15

Large uncertainties in the budget of atmospheric methane (CH4) limit the accuracy of climate change projections. Here we describe and quantify an important source of CH4 -- point-source ebullition (bubbling) from northern lakes -- that has not been incorporated in previous regional or global methane budgets. Employing a method recently introduced to measure ebullition more accurately by taking into account its spatial patchiness in lakes, we estimate point-source ebullition for 16 lakes in Alaska and Siberia that represent several common northern lake types: glacial, alluvial floodplain, peatland and thermokarst (thaw) lakes. Extrapolation of measured fluxes from these 16 sites to all lakes north of 45 degrees N using circumpolar databases of lake and permafrost distributions suggests that northern lakes are a globally significant source of atmospheric CH4, emitting approximately 24.2+/-10.5Tg CH4yr(-1). Thermokarst lakes have particularly high emissions because they release CH4 produced from organic matter previously sequestered in permafrost. A carbon mass balance calculation of CH4 release from thermokarst lakes on the Siberian yedoma ice complex suggests that these lakes alone would emit as much as approximately 49000Tg CH4 if this ice complex was to thaw completely. Using a space-for-time substitution based on the current lake distributions in permafrost-dominated and permafrost-free terrains, we estimate that lake emissions would be reduced by approximately 12% in a more probable transitional permafrost scenario and by approximately 53% in a 'permafrost-free' Northern Hemisphere. Long-term decline in CH4 ebullition from lakes due to lake area loss and permafrost thaw would occur only after the large release of CH4 associated thermokarst lake development in the zone of continuous permafrost.

Evidence for early hunters beneath the Great Lakes

OpenAIRE

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

2009-01-01

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

Utilization of a Marketing Strategy at Naval Regional Medical Center Great Lakes, Great Lakes, Illinois

Science.gov (United States)

1983-06-01

22 Analysis of the Mare.....................22 Development of the Marketing Mix .. .......... 29 A Marketing Mix --Recommendations...problem. Marketing strategy, marketing mix and ultimately the marketing orientation will allow hospitals to persevere and possibly thrive in a somewhat...market are currently being met at Naval Regional Medical Center Great Lakes. The fourth objective is to demonstrate an appropriate marketing mix for

Preliminary assessment of the impact of fluctuating water levels on northern pike in Reindeer Lake

International Nuclear Information System (INIS)

Chen, M.

1993-03-01

Reindeer Lake in north eastern Saskatchewan regulates water levels for the Island Falls hydroelectric power plant. Since inception of the Whitesand Dam on the lake, there have been concerns that fluctuating water levels could be adversely impacting the habitat and population of northern pike in the lake. The extent of water level fluctuations during the pike spawning period of Reindeer Lake and its effect on spawning success was investigated. Since construction of the Whitesand Dam in 1942 Reindeer Lake water levels have averaged ca 1.71 m higher than had the dam not existed, creating ca 430 km 2 of new surface area. Much of this area is shallow water and prone to growth of aquatic vegetation, which is suitable spawning and nursery habitat for northern pike. Annual and periodic water level fluctuations of Reindeer Lake have been higher than under natural conditions. During northern pike spawning and nursing periods, water levels in the lake have generally increased, in 60 out of 64 y. It is concluded that operation of the dam has not caused any direct negative impacts on the northern pike habitat in the lake. 2 refs., 4 figs., 4 tabs

Genetic diversity of wild and hatchery lake trout populations: Relevance for management and restoration in the Great Lakes

Science.gov (United States)

Page, K.S.; Scribner, K.T.; Burnham-Curtis, M.

2004-01-01

The biological diversity of lake trout Salvelinus namaycush in the upper Great Lakes was historically high, consisting of many recognizable morphological types and discrete spawning populations. During the 1950s and 1960s, lake trout populations were extirpated from much of the Great Lakes primarily as a result of overfishing and predation by the parasitic sea lamprey Petromyzon marinus. Investigations of how genetic diversity is partitioned among remnant wild lake trout populations and hatchery broodstocks have been advocated to guide lake trout management and conservation planning. Using microsatellite genetic markers, we estimated measures of genetic diversity and the apportionment of genetic variance among 6 hatchery broodstocks and 10 wild populations representing three morphotypes (lean, humper, and siscowet). Analyses revealed that different hatchery broodstocks and wild populations contributed disproportionally to the total levels of genetic diversity. The genetic affinities of hatchery lake trout reflected the lake basins of origin of the wild source populations. The variance in allele frequency over all sampled extant wild populations was apportioned primarily on the basis of morphotype (??MT = 0.029) and secondarily among geographically dispersed populations within each morphotype (??ST = 0.024). The findings suggest that the genetic divergence reflected in recognized morphotypes and the associated ecological and physiological specialization occurred prior to the partitioning of large proglacial lakes into the Great Lakes or as a consequence of higher contemporary levels of gene flow within than among morphotypes. Information on the relative contributions of different broodstocks to total gene diversity within the regional hatchery program can be used to prioritize the broodstocks to be retained and to guide future stocking strategies. The findings highlight the importance of ecological and phenotypic diversity in Great Lakes fish communities and

Climate change and water quality in the Great Lakes Basin

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-08-01

The Great Lakes Basin is subjected to several stresses, such as land use changes, chemical contamination, nutrient over-enrichment, alien invasive species, and acid precipitation. Climate change is now added to this list. The Water Quality Board was asked to provide advice concerning the impacts of climate change on the water quality of the Great Lakes and on how to address the issue. A White Paper was commissioned by the Board to address four key questions: (1) what are the Great Lakes water quality issues associated with climate change, (2) what are potential impacts of climate change on beneficial uses, (3) how might impacts vary across the Great Lakes region, and (4) what are the implications for decision making. The conclusions and findings of the White Paper were then discussed at a workshop held in May 2003. Part 1 of the document provides an executive summary. The advice of the Water Quality Board was based on the findings of the White Paper and presented in Part 2. Part 3 presented the White Paper, while a summary of the workshop was provided in Part 4. A presentation on cross border tools and strategies was also presented by a workshop participant.

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.

Questioning the Origin of the Great Salt Lake "Microbialites"

Science.gov (United States)

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

2017-12-01

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

It's like night and day: Diel net-effects on Cercopagidae densities in the Laurentian Great Lakes

Science.gov (United States)

Armenio, Patricia M.; Bunnell, David B.; Adams, Jean V.; Watson, Nicole M.; Woelmer, Whitney

2017-01-01

In the Laurentian Great Lakes, zooplankters are often sampled using standard ≤153 μm mesh nets without regard to the time of day they are collected. We sampled Cercopagidae during 2013–2014 in northern Lake Huron during day, dusk, and night using two different nets (a 0.5 m wide 153 μm mesh “standard” net and a 0.75 m wide 285 μm mesh “Bythotrephes” net) to determine if there were any differences in their sampled densities. Bythotrephes densities with the standard net were approximately 2.07-fold greater when captured at night than during the day. No time of day bias occurred with the Bythotrephes net. Nighttime Bythotrephes densities did not differ between the two net types. Cercopagis densities did not vary with net type or the time of day in this study, but future work should revisit this result given our low sample size and the low occurrence of Cercopagis in Lake Huron. To reduce bias and calculate accurate density estimates, Cercopagidae should be sampled at night if using a standard net or any time of day with the Bythotrephes net. Given the large impact of invasive predatory cladocerans Bythotrephes longimanus and Cercopagis pengoi on food webs since their invasion in the Laurentian Great Lakes in the 1980s, proper estimation of their densities is essential.

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.

Forging the Link: Using a Conservative Mixing Framework to Characterize Connections between Rivers and Great Lakes in River-lake Transition Zones

Science.gov (United States)

River-to-Great Lake transition zones are hydrologically, biogeochemically and biologically dynamic areas that regulate nutrient and energy fluxes between rivers and Great Lakes. Our goal is to characterize the biogeochemical properties of the river-lake transition zones and under...

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

A diatom record of recent environmental change in Lake Duluti, northern Tanzania

DEFF Research Database (Denmark)

Öberg, Helena; Andersen, Thorbjørn Joest; Westerberg, Lars-Ove

2012-01-01

Lake Duluti is a small, topographically closed crater lake located on the flanks of Mt Meru, northern Tanzania. Analyses of diatoms in three short sediment cores and four modern samples from Lake Duluti were used to infer past environmental changes. 210Pb and 137Cs activity profiles combined...

Evidence for early hunters beneath the Great Lakes.

Science.gov (United States)

O'Shea, John M; Meadows, Guy A

2009-06-23

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

Temperature variations in the southern Great Lakes during the last deglaciation: Comparison between pollen and GDGT proxies

Science.gov (United States)

Watson, Benjamin I.; Williams, John W.; Russell, James M.; Jackson, Stephen T.; Shane, Linda; Lowell, Thomas V.

2018-01-01

Our understanding of deglacial climate history in the southern Great Lakes region of the United States is primarily based upon fossil pollen data, with few independent and multi-proxy climate reconstructions. Here we introduce a new, well-dated fossil pollen record from Stotzel-Leis, OH, and a new deglacial temperature record based on branched glycerol dialkyl glycerol tetraethers (brGDGTs) at Silver Lake, OH. We compare these new data to previously published records and to a regional stack of pollen-based temperature reconstructions from Stotzel-Leis, Silver Lake, and three other well-dated sites. The new and previously published pollen records at Stotzel-Leis are similar, but our new age model brings vegetation events into closer alignment with known climatic events such as the Younger Dryas (YD). brGDGT-inferred temperatures correlate strongly with pollen-based regional temperature reconstructions, with the strongest correlation obtained for a global soil-based brGDGT calibration (r2 = 0.88), lending confidence to the deglacial reconstructions and the use of brGDGT and regional pollen stacks as paleotemperature proxies in eastern North America. However, individual pollen records show large differences in timing, rates, and amplitudes of inferred temperature change, indicating caution with paleoclimatic inferences based on single-site pollen records. From 16.0 to 10.0ka, both proxies indicate that regional temperatures rose by ∼10 °C, roughly double the ∼5 °C estimates for the Northern Hemisphere reported in prior syntheses. Change-point analysis of the pollen stack shows accelerated warming at 14.0 ± 1.2ka, cooling at 12.6 ± 0.4ka, and warming from 11.6 ± 0.5ka into the Holocene. The timing of Bølling-Allerød (B-A) warming and YD onset in our records lag by ∼300–500 years those reported in syntheses of temperature records from the northern mid-latitudes. This discrepancy is too large to be attributed to uncertainties in

Mapping ecosystem services in a Great Lakes estuary supports local decision-making

Science.gov (United States)

Estuaries of the Laurentian Great Lakes provide a concentrated supply of ecosystem goods and services from which humans benefit. As long-term centers of human activity, most estuaries of the Great Lakes and have a legacy of chemical contamination, degraded habitats, and non-point...

40 CFR Appendix B to Part 132 - Great Lakes Water Quality Initiative

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Great Lakes Water Quality Initiative B Appendix B to Part 132 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS... Water Quality Initiative Methodology for Deriving Bioaccumulation Factors Great Lakes States and Tribes...

Progress in understanding the importance of coastal wetland nursery habitat to Great Lakes fisheries support

Science.gov (United States)

Great Lakes coastal wetlands provide important habitat for Great Lakes fishes of all life stages. A literature review of ichthyoplankton surveys conducted in Great Lakes coastal wetlands found at least 82 species reported to be captured during the larval stage. Twenty of those sp...

Shallow Water Offshore Wind Optimization for the Great Lakes (DE-FOA-0000415) Final Report: A Conceptual Design for Wind Energy in the Great Lakes

Energy Technology Data Exchange (ETDEWEB)

Wissemann, Chris [Freshwater Wind I, LLC, Youngstown, OH (United States); White, Stanley M [Stanley White Engineering LLC, Noank, CT (United States)

2014-02-28

The primary objective of the project was to develop a innovative Gravity Base Foundation (GBF) concepts, including fabrication yards, launching systems and installation equipment, for a 500MW utility scale project in the Great Lakes (Lake Erie). The goal was to lower the LCOE by 25%. The project was the first to investigate an offshore wind project in the Great Lakes and it has furthered the body of knowledge for foundations and installation methods within Lake Erie. The project collected historical geotechnical information for Lake Erie and also used recently obtained data from the LEEDCo Icebreaker Project (FOA DE-EE0005989) geotechnical program to develop the conceptual designs. Using these data-sets, the project developed design wind and wave conditions from actual buoy data in order to develop a concept that would de-risk a project using a GBF. These wind and wave conditions were then utilized to create reference designs for various foundations specific to installation in Lake Erie. A project partner on the project (Weeks Marine) provided input for construction and costing the GBF fabrication and installation. By having a marine contractor with experience with large marine projects as part of the team provides credibility to the LCOE developed by NREL. NREL then utilized the design and construction costing information as part of the LCOE model. The report summarizes the findings of the project; Developed a cost model and “baseline” LCOE; Documented Site Conditions within Lake Erie; Developed Fabrication, Installation and Foundations Innovative Concept Designs; Evaluated LCOE Impact of Innovations; Developed Assembly line “Rail System” for GBF Construction and Staging; Developed Transit-Inspired Foundation Designs which incorporated: Semi-Floating Transit with Supplemental Pontoons Barge mounted Winch System; Developed GBF with “Penetration Skirt”; Developed Integrated GBF with Turbine Tower; Developed Turbine, Plant Layout and O&M Strategies. The

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.

Compilation of watershed models for tributaries to the Great Lakes, United States, as of 2010, and identification of watersheds for future modeling for the Great Lakes Restoration Initiative

Science.gov (United States)

Coon, William F.; Murphy, Elizabeth A.; Soong, David T.; Sharpe, Jennifer B.

2011-01-01

As part of the Great Lakes Restoration Initiative (GLRI) during 2009–10, the U.S. Geological Survey (USGS) compiled a list of existing watershed models that had been created for tributaries within the United States that drain to the Great Lakes. Established Federal programs that are overseen by the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Army Corps of Engineers (USACE) are responsible for most of the existing watershed models for specific tributaries. The NOAA Great Lakes Environmental Research Laboratory (GLERL) uses the Large Basin Runoff Model to provide data for the management of water levels in the Great Lakes by estimating United States and Canadian inflows to the Great Lakes from 121 large watersheds. GLERL also simulates streamflows in 34 U.S. watersheds by a grid-based model, the Distributed Large Basin Runoff Model. The NOAA National Weather Service uses the Sacramento Soil Moisture Accounting model to predict flows at river forecast sites. The USACE created or funded the creation of models for at least 30 tributaries to the Great Lakes to better understand sediment erosion, transport, and aggradation processes that affect Federal navigation channels and harbors. Many of the USACE hydrologic models have been coupled with hydrodynamic and sediment-transport models that simulate the processes in the stream and harbor near the mouth of the modeled tributary. Some models either have been applied or have the capability of being applied across the entire Great Lakes Basin; they are (1) the SPAtially Referenced Regressions On Watershed attributes (SPARROW) model, which was developed by the USGS; (2) the High Impact Targeting (HIT) and Digital Watershed models, which were developed by the Institute of Water Research at Michigan State University; (3) the Long-Term Hydrologic Impact Assessment (L–THIA) model, which was developed by researchers at Purdue University; and (4) the Water Erosion Prediction Project (WEPP) model, which was

Incidental oligotrophication of North American Great Lakes.

Science.gov (United States)

Evans, Mary Anne; Fahnenstiel, Gary; Scavia, Donald

2011-04-15

Phytoplankton production is an important factor in determining both ecosystem stability and the provision of ecosystem goods and services. The expansive and economically important North American Great Lakes are subjected to multiple stressors and understanding their responses to those stresses is important for understanding system-wide ecological controls. Here we show gradual increases in spring silica concentration (an indicator of decreasing growth of the dominant diatoms) in all basins of Lakes Michigan and Huron (USA and Canadian waters) between 1983 and 2008. These changes indicate the lakes have undergone gradual oligotrophication coincident with and anticipated by nutrient management implementation. Slow declines in seasonal drawdown of silica (proxy for seasonal phytoplankton production) also occurred, until recent years, when lake-wide responses were punctuated by abrupt decreases, putting them in the range of oligotrophic Lake Superior. The timing of these dramatic production drops is coincident with expansion of populations of invasive dreissenid mussels, particularly quagga mussels, in each basin. The combined effect of nutrient mitigation and invasive species expansion demonstrates the challenges facing large-scale ecosystems and suggest the need for new management regimes for large ecosystems.

46 CFR 117.206 - Survival craft-vessels operating on Great Lakes routes.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Survival craft-vessels operating on Great Lakes routes... PASSENGERS LIFESAVING EQUIPMENT AND ARRANGEMENTS Number and Type of Survival Craft § 117.206 Survival craft... vessel certificated to operate on a Great Lakes route must be provided with the survival craft required...

Reaching Regional and Local Learners via a Great Lakes MOOC

Science.gov (United States)

Mooney, M. E.; Ackerman, S. A.

2015-12-01

The Cooperative Institute of Meteorological Satellite Studies (CIMSS) took a regional approach to climate change education in a 4-week MOOC (Massive Open On-line Course) on the Changing Weather and Climate in the Great Lakes Region launched in February 2015. Featuring a different season each week, this Great Lakes MOOC includes lectures about seasonal weather conditions, observed changes, and societal impacts of regional climate change, as well as actions with co-benefits to slow future climate change. To better connect with learners, CIMSS facilitated 21 discussion groups at public libraries around Wisconsin each week. Participants discussed climate change impacts in their communities as well as strategies to mitigate climate change. Not surprisingly, initial survey results show library participants were more committed, engaged, climate literate, and community minded. This session will share lessons learned and survey results from the Great Lakes MOOC which remains open and accessible on Coursera through February 2016 at https://www.coursera.org/course/greatlakesclimate.

Artificial propagation of coregonines in the management of the Laurentian Great Lakes

Science.gov (United States)

Todd, Thomas N.

1986-01-01

Numerous stresses caused wide fluctuations in the abundance of Great Lakes coregonine fishes during the last century. State, Provincial, and Federal agencies attempted to bolster these fisheries by stocking more than 32 billion fry of lake whitefish (Coregonus clupeaformis) and 6 billion fry of lake herring (C. artedii) over a period of about 90 years (1870-1960). Propagation efforts were unsuccessful in arresting the decline of these fishes, perhaps because the stocking densities were too low. It appears that stocking densities must exceed 41% of the natural hatch to produce measurable success in a planting program that augments natural reproduction. Stocking of any of the Great Lakes with lake whitefish at these levels would require several billion fry per lake annually. Such a program is too large to be practical and intensified protection of the remaining stocks would be more cost effective. A species such as the shortnose cisco (C. reighardi) which has only a small number of extant individuals, and can therefore be significantly augmented with fewer stocked fish, may be a much better candidate for propagation than is the lake whitefish. Propagation of coregonines in the Great Lakes should be considered only in localities that have little or no natural recruitment and then only for rehabilitation, and only if accompanied by adequate assessment of the performance of the stocked fish.

Distribution of fallout plutonium in the waters of the lower Great Lakes

International Nuclear Information System (INIS)

Alberts, J.J.; Wahlgren, M.A.; Nelson, D.M.

1976-01-01

The concentrations of fallout 239 240 Pu in the surface waters from all the Great Lakes were slightly lower in 1976 samples than in those from 1973. The same trend of higher concentrations in the surface waters of the upper lakes as in the surface waters of the lower lakes was observed for both years. In addition, the 239 240 Pu concentration in samples of deep water collected during the summer of 1976 was higher than in the surface waters but was similar to the surface water values of the 1973 spring samples. This observation is significant in that it suggests that the surface waters of all the Great Lakes undergo a seasonal decrease in plutonium concentration similar to that already observed in Lake Michigan

46 CFR 180.206 - Survival craft-vessels operating on Great Lakes routes.

Science.gov (United States)

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Survival craft-vessels operating on Great Lakes routes... Craft § 180.206 Survival craft—vessels operating on Great Lakes routes. (a) Except as allowed by... with the survival craft required by § 180.205 (a) through (e), as appropriate. (b) Each vessel...

Mid Holocene lake level and shoreline behavior during the Nipissing phase of the upper Great Lakes at Alpena, Michigan, USA

Science.gov (United States)

Thompson, T.A.; Lepper, K.; Endres, A.L.; Johnston, J.W.; Baedke, S.J.; Argyilan, E.P.; Booth, R.K.; Wilcox, D.A.

2011-01-01

The Nipissing phase was the last pre-modern high-water stage of the upper Great Lakes. Represented as either a one- or two-peak highstand, the Nipissing occurred following a long-term lake-level rise. This transgression was primarily an erosional event with only the final stage of the transgression preserved as barriers, spits, and strandplains of beach ridges. South of Alpena, Michigan, mid to late Holocene coastal deposits occur as a strandplain between Devils Lake and Lake Huron. The landward part of this strandplain is a higher elevation platform that formed during the final stage of lake-level rise to the Nipissing peak. The pre-Nipissing shoreline transgressed over Devils Lake lagoonal deposits from 6.4 to 6.1. ka. The first beach ridge formed ~ 6. ka, and then the shoreline advanced toward Lake Huron, producing beach ridges about every 70. years. This depositional regression produced a slightly thickening wedge of sediment during a lake-level rise that formed 20 beach ridges. The rise ended at 4.5. ka at the Nipissing peak. This peak was short-lived, as lake level fell > 4. m during the following 500. years. During this lake-level rise and subsequent fall, the shoreline underwent several forms of shoreline behavior, including erosional transgression, aggradation, depositional transgression, depositional regression, and forced regression. Other upper Great Lakes Nipissing platforms indicate that the lake-level change observed at Alpena of a rapid pre-Nipissing lake-level rise followed by a slower rise to the Nipissing peak, and a post-Nipissing rapid lake-level fall is representative of mid Holocene lake level in the upper Great Lakes. ?? 2011 Elsevier B.V.

The Younger Dryas phase of Great Salt Lake, Utah, USA

Science.gov (United States)

Oviatt, Charles G.; Miller, D.M.; McGeehin, J.P.; Zachary, C.; Mahan, S.

2005-01-01

Field investigations at the Public Shooting Grounds (a wildlife-management area on the northeastern shore of Great Salt Lake) and radiocarbon dating show that the Great Salt Lake rose to the Gilbert shoreline sometime between 12.9 and 11.2 cal ka. We interpret a ripple-laminated sand unit exposed at the Public Shooting Grounds, and dated to this time interval, as the nearshore sediments of Great Salt Lake deposited during the formation of the Gilbert shoreline. The ripple-laminated sand is overlain by channel-fill deposits that overlap in age (11.9-11.2 cal ka) with the sand, and by wetland deposits (11.1 to 10.5 cal ka). Consistent accelerator mass spectrometry radiocarbon ages were obtained from samples of plant fragments, including those of emergent aquatic plants, but mollusk shells from spring and marsh deposits yielded anomalously old ages, probably because of a variable radiocarbon reservoir effect. The Bonneville basin was effectively wet during at least part of the Younger Dryas global-cooling interval, however, conflicting results from some Great Basin locations and proxy records indicate that the regional effects of Younger Dryas cooling are still not well understood. ?? 2005 Elsevier B.V. All rights reserved.

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.

Compsopogon cf. coeruleus, a benthic red alga (Rhodophyta) new to the Laurentian Great Lakes

Science.gov (United States)

Manny, Bruce A.; Edsall, Thomas A.; Wujek, Daniel E.

1991-01-01

We found Compsopogon cf. coeruleus for the first time in the Laurentian Great Lakes, growing on limestone rocks at a depth of 21 m on Six Fathom Bank in central Lake Huron. It is the first freshwater red alga to be found in the Great Lakes and the only red alga ever found on an offshore reef in the Great Lakes. However, because this alga usually inhabits water 10–28 °C and has not survived freezing winter temperatures elsewhere, it may not be a permanent member of the flora.

The PIRLA project: paleoecological investigations of recent lake acidification

Energy Technology Data Exchange (ETDEWEB)

Charles, D F; Whitehead, D R

1986-12-19

The PIRLA project is a broadly interdisciplinary paleolimnological investigation of five to fifteen comparable watershed lake systems from each of four low-alkalinity regions in North America that are currently receiving acid deposition. The areas are the Adirondack Mountains (N.Y.), northern New England, northern Great Lakes states, and northern Florida. The primary objective of the study is to provide a detailed reconstruction of the recent acidification histories of a representative suite of lakes from each of the regions. The study will increase our understanding of the timing, rates, and magnitude of acidification (and other chemical changes), and the regional and inter-regional patterns of lake acidification. 3 figs., 2 tabs., 41 refs.

Assessment of the Great Lakes Marine Renewable Energy Resources: Characterizing Lake Erie Surge, Seiche and Waves

Science.gov (United States)

Farhadzadeh, A.; Hashemi, M. R.

2016-02-01

Lake Erie, the fourth largest in surface area, smallest in volume and shallowest among the Great Lakes is approximately 400 km long and 90 km wide. Short term lake level variations are due to storm surge generated by high winds and moving pressure systems over the lake mainly in the southwest-northeast direction, along the lakes longitudinal axis. The historical wave data from three active offshore buoys shows that significant wave height can exceed 5 m in the eastern and central basins. The long-term lake level data show that storm surge can reach up to 3 m in eastern Lake Erie. Owing its shallow depth, Lake Erie frequently experiences seiching motions, the low frequency oscillations that are initiated by storm surge. The seiches whose first mode of oscillations has a period of nearly 14.2 hours can last from several hours to days. In this study, the Lake Erie potential for power generation, primarily using storm surge and seiche and also waves are assessed. Given the cyclic lake level variations due to storm-induced seiching, a concept similar to that of tidal range development is utilized to assess the potential of storm surge and seiche energy harvesting mechanisms for power generation. In addition, wave energy resources of the Lake is characterized -. To achieve these objectives, the following steps are taken : (1) Frequency of occurrence for extreme storm surge and wave events is determined using extreme value analysis such as Peak-Over-Threshold method for the long-term water level and wave data; (2) Spatial and temporal variations of wave height, storm surge and seiche are characterized. The characterization is carried out using the wave and storm surge outputs from numerical simulation of a number of historical extreme events. The coupled ADCIRC and SWAN model is utilized for the modeling; (3) Assessment of the potentials for marine renewable power generation in Lake Erie is made. The approach can be extended to the other lakes in the Great Lakes region.

Seasonal patterns in growth, blood consumption, and effects on hosts by parasitic-phase sea lampreys in the Great Lakes: an individual-based model approach

Science.gov (United States)

Madenjian, Charles P.; Cochran, Philip A.; Bergstedt, Roger A.

2003-01-01

An individual-based model (IBM) was developed for sea lamprey (Petromyzon marinus) populations in the Laurentian Great Lakes. The IBM was then calibrated to observed growth, by season, for sea lampreys in northern Lake Huron under two different water temperature regimes: a regime experienced by Seneca-strain lake trout (Salvelinus namaycush) and a regime experienced by Marquettestrain lake trout. Modeling results indicated that seasonal blood consumption under the Seneca regime was very similar to that under the Marquette regime. Simulated mortality of lake trout directly due to blood removal by sea lampreys occurred at nearly twice the rate during August and September under the Marquette regime than under the Seneca regime. However, cumulative sea lamprey-induced mortality on lake trout over the entire duration of the sea lamprey's parasitic phase was only 7% higher for the Marquette regime compared with the Seneca regime. Thus, these modeling results indicated that the strain composition of the host (lake trout) population was not important in determining total number of lake trout deaths or total blood consumption attributable to the sea lamprey population, given the sea lamprey growth pattern. Regardless of water temperature regime, both blood consumption rate by sea lampreys and rate of sea lamprey-induced mortality on lake trout peaked in late October. Elevated blood consumption in late October appeared to be unrelated to changes in water temperature. The IBM approach should prove useful in optimizing control of sea lampreys in the Laurentian Great Lakes.

Vegetative substrates used by larval northern pike in Rainy and Kabetogama Lakes, Minnesota

Science.gov (United States)

Anne L. Timm; Rodney B. Pierce

2015-01-01

Our objective was to identify characteristics of aquatic vegetative communities used as larval northern pike nursery habitat in Rainy and Kabetogama lakes, glacial shield reservoirs in northern Minnesota. Quatrefoil light traps fished at night were used to sample larval northern pike in 11 potential nursery areas. Larval northern pike were most commonly sampled among...

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

3 CFR - National Policy for the Oceans, Our Coasts, and the Great Lakes

Science.gov (United States)

2010-01-01

... sustainable oceans, coasts, and Great Lakes resources for the benefit of this and future generations. Yet, the... conservation, economic activity, user conflict, and sustainable use of ocean, coastal, and Great Lakes... publish this memorandum in the Federal Register.BARACK OBAMATHE WHITE HOUSE, Washington, June 12, 2009. ...

Partners in flight bird conservation plan for the Upper Great Lakes Plain (Physiographic Area 16)

Science.gov (United States)

Knutson, M.G.; Butcher, G.; Fitzgerald, J.; Shieldcastle, J.

2001-01-01

1 November 2001. Conservation of bird habitats is a major focus of effort by Partners in Flight, an international coalition of agencies, citizens, and other groups dedicated to 'keeping common birds common'. USGS worked on a planning team to publish a bird conservation plan for the Upper Great Lakes Plain ecoregion (PIF 16), which includes large portions of southern Wisconsin, southern Michigan and parts of Minnesota, Iowa, Illinois, Indiana, and Ohio. The conservation plan outlines specific habitat restoration and bird population objectives for the ecoregion over the next decade. The plan provides a context for on-the-ground conservation implementation by the US Fish and Wildlife Service, the USDA Natural Resources Conservation Service, the US Forest Service, states, and conservation groups. Citation: Knutson, M. G., G. Butcher, J. Fitzgerald, and J. Shieldcastle. 2001. Partners in Flight Bird Conservation Plan for The Upper Great Lakes Plain (Physiographic Area 16). USGS Upper Midwest Environmental Sciences Center in cooperation with Partners in Flight, La Crosse, Wisconsin. Download from website: http://www.blm.gov/wildlife/pifplans.htm. The Upper Great Lakes Plain covers the southern half of Michigan, northwest Ohio, northern Indiana, northern Illinois, southern Wisconsin, and small portions of southwest Minnesota and northwest Iowa. Glacial moraines and dissected plateaus are characteristic of the topography. Broadleaf forests, oak savannahs, and a variety of prairie communities are the natural vegetation types. A oDriftless Areao was not glaciated during the late Pleistocene and emerged as a unique area of great biological diversity. Priority bird species for the area include the Henslow's Sparrow, Sedge Wren, Bobolink, Golden-winged Warbler, Cerulean Warbler, Black-billed Cuckoo, and Red-headed Woodpecker. There are many large urban centers in this area whose growth and sprawl will continue to consume land. The vast majority of the presettlement forest and

Growth-climate relationships across topographic gradients in the northern Great Lakes

Science.gov (United States)

Dymond, S.F.; D'Amato, A.W.; Kolka, R.K.; Bolstad, P.V.; Sebestyen, S.D.; Bradford, John B.

2016-01-01

Climatic conditions exert important control over the growth, productivity, and distribution of forests, and characterizing these relationships is essential for understanding how forest ecosystems will respond to climate change. We used dendrochronological methods to develop climate–growth relationships for two dominant species, Populus tremuloides (quaking aspen) and Pinus resinosa (red pine), in the upper Great Lakes region to understand how climate and water availability influence annual forest productivity. Trees were sampled along a topographic gradient at the Marcell Experimental Forest (Minnesota, USA) to assess growth response to variations in temperature and different water availability metrics (precipitation, potential evapotranspiration (PET), cumulative moisture index (CMI), and soil water storage). Climatic variables were able to explain 33–58% of the variation in annual growth (as measured by ring-width increment) for quaking aspen and 37–74% of the variation for red pine. Climate–growth relationships were influenced by topography for quaking aspen but not for red pine. Annual ring growth for quaking aspen decreased with June CMI on ridges, decreased with temperature in the November prior to the growing season on sideslopes, and decreased with June PET on toeslopes. Red pine growth increased with increasing July PET across all topographic positions. These results indicate the sensitivity of both quaking aspen and red pine to local climate and show several vulnerabilities of these species to shifts in water supply and temperature because of climate change.

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.

The northern lakes of Egypt: Encounters with a wetland environment

International Nuclear Information System (INIS)

Parmenter, B.M.

1991-01-01

Five lakes fringe the northern coast of Egypt. Together they represent 25% of the remaining wetland habitat in the Mediterranean basin. Residents of these lakes traditionally exploited a wide variety of resources. Today these lakes face a number of threats to their existence, including large-scale reclamation and water pollution. Agricultural authorities, engineers, fishery managers, and conservationists in Egypt and abroad debate about how best to manage and develop the lake region's resources, but few of these groups understand or communicate with one another, or with residents of lake communities. This study explores how these various groups encounter the coastal lakes of Egypt, focusing particularly on Lakes Manzala and Burullus. Its purpose is to explore the ways in which the lakes, their resources and their inhabitants have been evaluated, and to analyze how underlying preconceptions, goals and structures of professional discourse influence such evaluations. The thesis is that environmental management is in reality not a rational plan but a process. Egypt is currently attempting to develop a coherent strategy to remedy its environmental problems without adversely affecting economic growth

Developing Flexible, Integrated Hydrologic Modeling Systems for Multiscale Analysis in the Midwest and Great Lakes Region

Science.gov (United States)

Hamlet, A. F.; Chiu, C. M.; Sharma, A.; Byun, K.; Hanson, Z.

2016-12-01

Physically based hydrologic modeling of surface and groundwater resources that can be flexibly and efficiently applied to support water resources policy/planning/management decisions at a wide range of spatial and temporal scales are greatly needed in the Midwest, where stakeholder access to such tools is currently a fundamental barrier to basic climate change assessment and adaptation efforts, and also the co-production of useful products to support detailed decision making. Based on earlier pilot studies in the Pacific Northwest Region, we are currently assembling a suite of end-to-end tools and resources to support various kinds of water resources planning and management applications across the region. One of the key aspects of these integrated tools is that the user community can access gridded products at any point along the end-to-end chain of models, looking backwards in time about 100 years (1915-2015), and forwards in time about 85 years using CMIP5 climate model projections. The integrated model is composed of historical and projected future meteorological data based on station observations and statistical and dynamically downscaled climate model output respectively. These gridded meteorological data sets serve as forcing data for the macro-scale VIC hydrologic model implemented over the Midwest at 1/16 degree resolution. High-resolution climate model (4km WRF) output provides inputs for the analyses of urban impacts, hydrologic extremes, agricultural impacts, and impacts to the Great Lakes. Groundwater recharge estimated by the surface water model provides input data for fine-scale and macro-scale groundwater models needed for specific applications. To highlight the multi-scale use of the integrated models in support of co-production of scientific information for decision making, we briefly describe three current case studies addressing different spatial scales of analysis: 1) Effects of climate change on the water balance of the Great Lakes, 2) Future

The effect of the United States Great Lakes on the maintenance of derecho-producing mesoscale convective systems.

Science.gov (United States)

Bentley, M.; Sparks, J.; Graham, R.

2003-04-01

The primary aim of this research is to investigate the influence of the United States Great Lakes on the intensity of mesoscale convective systems (MCSs). One of the greatest nowcast challenges during the warm season is anticipating the impact of the Great Lakes on severe convection, particularly MCSs capable of producing damaging widespread windstorms known as derechos. Since a major derecho activity corridor lies over the Great Lakes region, it is important to understand the effects of the Lakes on the intensity and propagation of severe wind producing MCSs. Specific objectives of the research include: 1) The development of a short-term climatology of MCS events that have impacted the Great Lakes region over the past seven years; 2) An analysis of radar, satellite, surface (including buoy and lighthouse observations), and lake surface temperature data to determine the environmental conditions impacting the evolution of MCSs passing over a Great Lake; 3) An examination of MCS initiation times and seasonal frequencies of occurrence to delineate temporal consistencies in MCS evolution due to changing lake surface temperatures; and 4) The development of conceptual and forecast models to help anticipate MCS intensity and morphology as these systems interact with the Great Lakes environment.

Decadal oscillation of lakes and aquifers in the upper Great Lakes region of North America: hydroclimatic implications

Science.gov (United States)

Watras, C.J.; Read, J.S.; Holman, K.D.; Liu, Z.; Song, Y.-Y.; Watras, A.J.; Morgan, S.; Stanley, E.H.

2014-01-01

We report a unique hydrologic time-series which indicates that water levels in lakes and aquifers across the upper Great Lakes region of North America have been dominated by a climatically-driven, near-decadal oscillation for at least 70 years. The historical oscillation (~13y) is remarkably consistent among small seepage lakes, groundwater tables and the two largest Laurentian Great Lakes despite substantial differences in hydrology. Hydrologic analyses indicate that the oscillation has been governed primarily by changes in the net atmospheric flux of water (P-E) and stage-dependent outflow. The oscillation is hypothetically connected to large-scale atmospheric circulation patterns originating in the mid-latitude North Pacific that support the flux of moisture into the region from the Gulf of Mexico. Recent data indicate an apparent change in the historical oscillation characterized by a ~12y downward trend beginning in 1998. Record low water levels region-wide may mark the onset of a new hydroclimatic regime.

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

Directory of Open Access Journals (Sweden)

Garry D. Peterson

2003-12-01

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

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

Science.gov (United States)

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

2014-11-01

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

Status of the amphipod Diporeia ssp. in coastal waters of the Laurentian Great Lakes

Science.gov (United States)

Diporeia has historically been the dominant benthic macroinvertebrate in deeper waters of the Laurentian Great Lakes, and its abundance has been proposed as an indicator of ecological condition. In 2010, the USEPA incorporated the Great Lakes into the National Coastal Condition A...

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

GLERL Great Lakes Ice Thickness Data Base, 1966-1979

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — During the winters of 1965/66 through 1976/77, NOAA/Great Lakes Environmental Research Laboratory (GLERL) collected weekly ice thickness and stratigraphy data at up...

40 CFR Appendix E to Part 132 - Great Lakes Water Quality Initiative Antidegradation Policy

Science.gov (United States)

2010-07-01

... most cost effective pollution prevention and treatment techniques available, and minimizes the... shall adopt an antidegradation standard applicable to all waters of the Great Lakes System and identify... result in an increased loading of BCCs to surface waters of the Great Lakes System and for which...

Alien invasive species and biological pollution of the Great Lakes Basin ecosystem[Great Lakes Water Quality Board : Report to the International Joint Commission

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-05-01

The displacement of important native species in the Great Lakes is a result of an invasion by a succession of non indigenous aquatic species. These invasion also resulted in interference with the proper human water uses and cost billions of dollars. The problem was considered serious enough that the International Joint Commission asked the Great Lakes Water Quality Board in 1999 to review the regulations in place and make recommendations, if necessary, for the implementation of additional measures that could be considered to keep control over the introduction of alien invasive species. Escapes from aquaria, aquaculture, research and educational facilities, canal and diversion water flows, and release of live bait are all sources of this invasion. The effectiveness of alternative technologies to control the invasion was to be examined by the Board. Other efforts taking place to address the situation in the basin are being complemented by the publication of this report. It is considered that the most important source of alien invasive species (AIS) to the Great Lakes is the discharge of ballast water from shipping vessels coming from outside the United States and Canada. A major concern is the role played by vessels reporting no ballast on board (NOBOB) upon entering the basin. A number of recommendations were made concerning: (1) implementation and enforcement of the ballast water discharge standards agreed upon by both countries, (2) the evaluation of the effectiveness of alternative technologies to achieve ballast water discharge standards over the long term, combined with the use of chemical treatment while the evaluation is being performed, (3) the implementation of optimal management practices to control sediments in shipping vessels, (4) modifications to the design of shipping vessels, and (5) the monitoring and contingency plans in the event of a repeat scenario in the future. Composed of an equal number representatives from the United States and Canada, at

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

Directory of Open Access Journals (Sweden)

Mariana FILIPOVA-MARINOVA

2014-11-01

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

Modeling the global atmospheric transport and deposition of mercury to the Great Lakes

Directory of Open Access Journals (Sweden)

Mark D. Cohen

2016-07-01

Full Text Available Abstract Mercury contamination in the Great Lakes continues to have important public health and wildlife ecotoxicology impacts, and atmospheric deposition is a significant ongoing loading pathway. The objective of this study was to estimate the amount and source-attribution for atmospheric mercury deposition to each lake, information needed to prioritize amelioration efforts. A new global, Eulerian version of the HYSPLIT-Hg model was used to simulate the 2005 global atmospheric transport and deposition of mercury to the Great Lakes. In addition to the base case, 10 alternative model configurations were used to examine sensitivity to uncertainties in atmospheric mercury chemistry and surface exchange. A novel atmospheric lifetime analysis was used to characterize fate and transport processes within the model. Model-estimated wet deposition and atmospheric concentrations of gaseous elemental mercury (Hg(0 were generally within ∼10% of measurements in the Great Lakes region. The model overestimated non-Hg(0 concentrations by a factor of 2–3, similar to other modeling studies. Potential reasons for this disagreement include model inaccuracies, differences in atmospheric Hg fractions being compared, and the measurements being biased low. Lake Erie, downwind of significant local/regional emissions sources, was estimated by the model to be the most impacted by direct anthropogenic emissions (58% of the base case total deposition, while Lake Superior, with the fewest upwind local/regional sources, was the least impacted (27%. The U.S. was the largest national contributor, followed by China, contributing 25% and 6%, respectively, on average, for the Great Lakes. The contribution of U.S. direct anthropogenic emissions to total mercury deposition varied between 46% for the base case (with a range of 24–51% over all model configurations for Lake Erie and 11% (range 6–13% for Lake Superior. These results illustrate the importance of atmospheric

METHYLMERCURY BIOACCUMULATION DEPENDENCE ON NORTHERN PIKE AGE AND SIZE IN TWENTY MINNESOTA LAKES

Science.gov (United States)

Mercury accumulation in northern pike muscle tissue (fillets) was found to be directly related to fish age and size. Measurements were made on 173 individual northern pike specimens from twenty lakes across Minnesota. Best fit regressions of mercury fillet concentration (wet wt.)...

Regulatory impact analysis of the proposed great lakes water quality guidance. Final report

International Nuclear Information System (INIS)

Raucher, R.; Dixon, A.; Trabka, E.

1993-01-01

The Regulatory Impact Analysis provides direction to the Great Lakes States and Tribes on minimum water quality standards and contains numerical water quality criteria for 32 pollutants as well as methodologies for the development of water quality criteria for additional pollutants discharged to these waters. It also provides guidance to the Great Lakes States and Tribes on antidegradation policies and standards and implementation procedures

Factors Affecting Mercury Stable Isotopic Distribution in Piscivorous Fish of the Laurentian Great Lakes.

Science.gov (United States)

Lepak, Ryan F; Janssen, Sarah E; Yin, Runsheng; Krabbenhoft, David P; Ogorek, Jacob M; DeWild, John F; Tate, Michael T; Holsen, Thomas M; Hurley, James P

2018-03-06

Identifying the sources of methylmercury (MeHg) and tracing the transformations of mercury (Hg) in the aquatic food web are important components of effective strategies for managing current and legacy Hg sources. In our previous work, we measured stable isotopes of Hg (δ 202 Hg, Δ 199 Hg, and Δ 200 Hg) in the Laurentian Great Lakes and estimated source contributions of Hg to bottom sediment. Here, we identify isotopically distinct Hg signatures for Great Lakes trout ( Salvelinus namaycush) and walleye ( Sander vitreus), driven by both food-web and water-quality characteristics. Fish contain high values for odd-isotope mass independent fractionation (MIF) with averages ranging from 2.50 (western Lake Erie) to 6.18‰ (Lake Superior) in Δ 199 Hg. The large range in odd-MIF reflects variability in the depth of the euphotic zone, where Hg is most likely incorporated into the food web. Even-isotope MIF (Δ 200 Hg), a potential tracer for Hg from precipitation, appears both disconnected from lake sedimentary sources and comparable in fish among the five lakes. We suggest that similar to the open ocean, water-column methylation also occurs in the Great Lakes, possibly transforming recently deposited atmospheric Hg deposition. We conclude that the degree of photochemical processing of Hg is controlled by phytoplankton uptake rather than by dissolved organic carbon quantity among lakes.

Global change-driven effects on dissolved organic matter composition: Implications for food webs of northern lakes.

Science.gov (United States)

Creed, Irena F; Bergström, Ann-Kristin; Trick, Charles G; Grimm, Nancy B; Hessen, Dag O; Karlsson, Jan; Kidd, Karen A; Kritzberg, Emma; McKnight, Diane M; Freeman, Erika C; Senar, Oscar E; Andersson, Agneta; Ask, Jenny; Berggren, Martin; Cherif, Mehdi; Giesler, Reiner; Hotchkiss, Erin R; Kortelainen, Pirkko; Palta, Monica M; Vrede, Tobias; Weyhenmeyer, Gesa A

2018-03-15

Northern ecosystems are experiencing some of the most dramatic impacts of global change on Earth. Rising temperatures, hydrological intensification, changes in atmospheric acid deposition and associated acidification recovery, and changes in vegetative cover are resulting in fundamental changes in terrestrial-aquatic biogeochemical linkages. The effects of global change are readily observed in alterations in the supply of dissolved organic matter (DOM)-the messenger between terrestrial and lake ecosystems-with potentially profound effects on the structure and function of lakes. Northern terrestrial ecosystems contain substantial stores of organic matter and filter or funnel DOM, affecting the timing and magnitude of DOM delivery to surface waters. This terrestrial DOM is processed in streams, rivers, and lakes, ultimately shifting its composition, stoichiometry, and bioavailability. Here, we explore the potential consequences of these global change-driven effects for lake food webs at northern latitudes. Notably, we provide evidence that increased allochthonous DOM supply to lakes is overwhelming increased autochthonous DOM supply that potentially results from earlier ice-out and a longer growing season. Furthermore, we assess the potential implications of this shift for the nutritional quality of autotrophs in terms of their stoichiometry, fatty acid composition, toxin production, and methylmercury concentration, and therefore, contaminant transfer through the food web. We conclude that global change in northern regions leads not only to reduced primary productivity but also to nutritionally poorer lake food webs, with discernible consequences for the trophic web to fish and humans. © 2018 John Wiley & Sons Ltd.

Tree-ring reconstruction of the level of Great Salt Lake, USA

Science.gov (United States)

R. Justin DeRose; Shih-Yu Wang; Brendan M. Buckley; Matthew F. Bekker

2014-01-01

Utah's Great Salt Lake (GSL) is a closed-basin remnant of the larger Pleistocene-age Lake Bonneville. The modern instrumental record of the GSL-level (i.e. elevation) change is strongly modulated by Pacific Ocean coupled ocean/atmospheric oscillations at low frequency, and therefore reflects the decadalscale wet/dry cycles that characterize the region. A within-...

Water circulation and recharge pathways of coastal lakes along the southern Baltic Sea in northern Poland

Directory of Open Access Journals (Sweden)

Cieśliński Roman

2016-12-01

Full Text Available The purpose of this paper is to describe water circulation patterns for selected lakes found along the Baltic coast in northern Poland and to determine primary recharge mechanisms or pathways that produce an influx or loss of lake water. A secondary purpose of the paper is to determine the magnitude of recharge for each studied source of water – river water influx, surface runoff from direct catchments, forced influx from polders surrounding lakes, and periodic marine water intrusions from the nearby Baltic Sea. It is also important to determine the magnitude of water outflow from lakes to the sea via existing linkages as well as to compare horizontal influx and outflow data. The study area consisted of five lakes located along the Baltic Sea in northern Poland: Łebsko, Gardno, Bukowo, Kopań, Resko Przymorskie. The main driving force of the studied lakes are large rivers that drain lake catchment areas and periodic brackish water intrusions by the Baltic Sea.

First evidence of microplastics in the African Great Lakes

DEFF Research Database (Denmark)

Biginagwa, Fares John; Mayoma, Bahati Sosthenes; Shashoua, Yvonne

2016-01-01

-FTIR) spectroscopy. A variety of polymer types were identified with likely sources being urban waste and consumer use. Although further research is required to fully assess the impact of plastic pollution in this region, our study is the first to report the presence of microplastics in Africa's Great Lakes...... on the southern shore of Lake Victoria. The gastrointestinal tracts of locally fished Nile perch (Lates niloticus) and Nile tilapia (Oreochromis niloticus) were examined for plastics. Plastics were confirmed in 20% of fish from each species by Attenuated Total Reflectance Fourier Transform Infrared (ATR...

Geologic map of Medicine Lake volcano, northern California

Science.gov (United States)

Donnelly-Nolan, Julie M.

2011-01-01

Medicine Lake volcano forms a broad, seemingly nondescript highland, as viewed from any angle on the ground. Seen from an airplane, however, treeless lava flows are scattered across the surface of this potentially active volcanic edifice. Lavas of Medicine Lake volcano, which range in composition from basalt through rhyolite, cover more than 2,000 km2 east of the main axis of the Cascade Range in northern California. Across the Cascade Range axis to the west-southwest is Mount Shasta, its towering volcanic neighbor, whose stratocone shape contrasts with the broad shield shape of Medicine Lake volcano. Hidden in the center of Medicine Lake volcano is a 7 km by 12 km summit caldera in which nestles its namesake, Medicine Lake. The flanks of Medicine Lake volcano, which are dotted with cinder cones, slope gently upward to the caldera rim, which reaches an elevation of nearly 8,000 ft (2,440 m). The maximum extent of lavas from this half-million-year-old volcano is about 80 km north-south by 45 km east-west. In postglacial time, 17 eruptions have added approximately 7.5 km3 to its total estimated volume of 600 km3, and it is considered to be the largest by volume among volcanoes of the Cascades arc. The volcano has erupted nine times in the past 5,200 years, a rate more frequent than has been documented at all other Cascades arc volcanoes except Mount St. Helens.

Stable Isotope Mass Balance of the Laurentian Great Lakes to Constrain Evaporative Losses

Energy Technology Data Exchange (ETDEWEB)

Jasechko, S. [Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario and Alberta Innovates, Technology Futures, Victoria, British Columbia (Canada); Gibson, J. J. [Canada Alberta Innovates, Technology Futures, Victoria, British Columbia and Department of Geography, University of Victoria, Victoria, British Columbia (Canada); Pietroniro, A. [National Water Research Institute, Environment Canada, Saskatoon, Saskatchewan (Canada); Edwards, T.W D. [Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario (Canada)

2013-07-15

Evaporation is an important yet poorly constrained component of the water budget of the Laurentian Great Lakes, but is known historically to have a significant impact on regional climate, including enhanced humidity and downwind lake effect precipitation. Sparse over lake climate monitoring continues to limit ability to quantify bulk lake evaporation and precipitation rates by physical measurements, impeded by logistical difficulties and costs of instrumenting large areas of open water (10{sup 3}-10{sup 5} km2). Measurements of stable isotopes of oxygen and hydrogen in water samples of precipitation and surface waters within the great lakes basin are used to better understand the controls on the region's water cycle. A stable isotope mass balance approach to calculate long term evaporation as a proportion of input to each lake is discussed. The approach capitalizes on the well understood systematic isotopic separation of an evaporating water body, but includes added considerations for internal recycling of evaporated moisture in the overlying atmosphere that should be incorporated for surface waters sufficiently large to significantly influence surrounding climate. (author)

Building a reference inventory of Great Lakes aquatic fauna

Science.gov (United States)

Despite the existence of numerous publications and web-pages that address aspects of species composition and distribution in the Great Lakes, there is at present no single resource that brings all this information together. This poster describes our progress towards generating a ...

Great Lakes rivermouth ecosystems: scientific synthesis and management implications

Science.gov (United States)

Rivermouth ecosystems contribute to both the ecological dynamics and the human social networks that surround and depend on the Laurentian Great Lakes. However, understanding and management of these systems would be enhanced by viewing them with a new, holistic focus. Here, focu...

Application of theory and research in fishery management of the Laurentian Great Lakes

Science.gov (United States)

Smith, Stanford H.

1973-01-01

The Great Lakes have a high potential for the conduct of research and useful application of research findings, but the history of the Great Lakes indicates that extensive research and intensive management have failed to prevent deterioration of the fisheries. At times the research was not done before a loss occurred, or did not provide the information needed to solve a problem, or was not interpreted to indicate a need for corrective action.

An ecosystem approach to the health effects of mercury in the Great Lakes basin ecosystem

International Nuclear Information System (INIS)

Gilbertson, Michael; Carpenter, D.O.

2004-01-01

New concerns about the global presence and human health significance of mercury have arisen as a result of recent epidemiological data demonstrating subtle neurological effects from consumption of mercury-contaminated fish. In the Great Lakes Basin, the complexity of the diverse sources, pools, and sinks of mercury and of the pathways of distribution, fate, and biotransformation requires an ecosystem approach to the assessment of exposures of Great Lakes' human populations. Further epidemiological research is needed to verify preliminary indications of harmful effects in people living near the Great Lakes. Great Lakes fish are valuable resources for subsistence nutrition, recreation, and commerce, but the benefits of fish consumption must be balanced by concern for the hazards from the contaminants that they may contain. The efficacy of fish consumption advisories in reducing exposures should continue to be evaluated while planning continues for remedial actions on contaminated sediments from historic industrial activities and for regulatory action to control sources

75 FR 35652 - Safety Zone; Northern California Annual Fireworks Events, Fourth of July Fireworks, South Lake...

Science.gov (United States)

2010-06-23

... Zone; Northern California Annual Fireworks Events, Fourth of July Fireworks, South Lake Tahoe Gaming... will enforce Lights on the Lake Fireworks Display safety zone for South Lake Tahoe, from 8:30 a.m. on... the Lake Fireworks in 33 CFR 165.1191 on July 4, 2010, from 8:30 a.m. on July 1, 2010 through 10 p.m...

Groundwater science relevant to the Great Lakes Water Quality Agreement: A status report

Science.gov (United States)

Grannemann, Norman G.; Van Stempvoort, Dale

2016-01-01

When the Great Lakes Water Quality Agreement (GLWQA) was signed in 1972 by the Governments of Canada and the United States (the “Parties”) (Environment Canada, 2013a), groundwater was not recognized as important to the water quality of the Lakes. At that time, groundwater and surface water were still considered as two separate systems, with almost no appreciation for their interaction. When the GLWQA was revised in 1978 (US Environmental Protection Agency (USEPA), 2012), groundwater contamination, such as that reported at legacy industrial sites such as those at Love Canal near the Niagara River, was squarely in the news. Consequently, the potential impacts of contaminated groundwater from such sites on Great Lakes water quality became a concern (Beck, 1979), and Annex 16 was added to the agreement, to address “pollution from contaminated groundwater” (Francis, 1989). However, no formal process for reporting under this annex was provided. The GLWQA Protocol in 1987 modified Annex 16 and called for progress reports beginning in 1988 (USEPA, 1988). The Protocol in 2012 provided a new Annex 8 to address groundwater more holistically (Environment 2 Canada, 2013b). Annex 8 (Environment Canada, 2013b) commits the Parties to coordinate groundwater science and management actions; as a first step, to “publish a report on the relevant and available groundwater science” by February 2015 (this report); and to “identify priorities for science activities and actions for groundwater management, protection, and remediation…” The broader mandate of Annex 8 is to (1) “identify groundwater impacts on the chemical, physical and biological integrity of the Waters of the Great Lakes;” (2) “analyze contaminants, including nutrients in groundwater, derived from both point and non-point sources impacting the Waters of the Great Lakes;” (3) “assess information gaps and science needs related to groundwater to protect the quality of the Waters of the Great Lakes

Toward Integrated Resource Management: Lessons About the EcosystemApproach from the Laurentian Great Lakes

Science.gov (United States)

MACKENZIE

1997-03-01

/ The ecosystem approach is an innovative tool for integratedresource management. Its goal is to restore, enhance, and protect ecosystemintegrity through a holistic and integrated mode of planning. Under thisapproach, the ecosystem itself becomes the unit of analysis and organizingprinciple for environmental management. Utilizing the ecosystem approachchallenges the prevailing structure and function of contemporary resourcemanagement agencies. This paper explores a number of important policy andmanagement issues in the context of a ten-year initiative to remediate theLaurentian Great Lakes using the ecosystem approach. The lessons gleaned fromthe Great Lakes experience are relevant to other areas in North America andabroad where resource management responsibilities are held by multiple andsometimes overlapping jurisdictions.KEY WORDS: Integrated resource management; Ecosystem approach; Watershedmanagement; Great Lakes

A Citizen Science Program for Monitoring Lake Stages in Northern Wisconsin

Science.gov (United States)

Kretschmann, A.; Drum, A.; Rubsam, J.; Watras, C. J.; Cellar-Rossler, A.

2011-12-01

Historical data indicate that surface water levels in northern Wisconsin are fluctuating more now than they did in the recent past. In the northern highland lake district of Vilas County, Wisconsin, concern about record low lake levels in 2008 spurred local citizens and lake associations to form a lake level monitoring network comprising citizen scientists. The network is administered by the North Lakeland Discovery Center (NLDC, a local NGO) and is supported by a grant from the Citizen Science Monitoring Program of the Wisconsin Department of Natural Resources (WDNR). With technical guidance from limnologists at neighboring UW-Madison Trout Lake Research Station, citizen scientists have installed geographic benchmarks and staff gauges on 26 area lakes. The project engages citizen and student science participants including homeowners, non-profit organization member-participants, and local schools. Each spring, staff gauges are installed and referenced to fixed benchmarks after ice off by NLDC and dedicated volunteers. Volunteers read and record staff gauges on a weekly basis during the ice-free season; and maintain log books recording lake levels to the nearest 0.5 cm. At the end of the season, before ice on, gauges are removed and log books are collected by the NLDC coordinator. Data is compiled and submitted to a database management system, coordinated within the Wisconsin Surface Water Integrated Monitoring System (SWIMS), a statewide information system managed by the WDNR in Madison. Furthermore, NLDC is collaborating with the SWIMS database manager to develop data entry screens based on records collected by citizen scientists. This program is the first of its kind in Wisconsin to utilize citizen scientists to collect lake level data. The retention rate for volunteers has been 100% over the three years since inception, and the program has expanded from four lakes in 2008 to twenty-six lakes in 2011. NLDC stresses the importance of long-term monitoring and the

Wetland Plants of Great Salt Lake, A Guide to Identification, Communities, & Bird Habitat

OpenAIRE

Downard, Rebekah; Frank, Maureen; Perkins, Jennifer; Kettenring, Karin; Larese-Casanova, Mark

2017-01-01

Wetland Plants of Great Salt Lake: a guide to identification, communities, & bird habitat is a wetland plant identification guide, resulting from collaborative research efforts about Great Salt Lake (GSL) wetland conditions and bird habitat. Dr. Rebekah Downard collected dissertation field data from GSL wetlands during 2012–2015, the majority of which informed this work. Dr. Maureen Frank contributed her guide to GSL wetland vegetation and how to manage native plants as high-quality habitat f...

78 FR 49544 - Great Lakes Pilotage Advisory Committee; Vacancies

Science.gov (United States)

2013-08-14

.... ADDRESSES: Send your cover letter and resume indicating the membership category for which you are applying... pilotage of vessels on the Great Lakes, and at least 5 years of practical experience in maritime operations..., national origin, political affiliation, sexual orientation, gender identity, marital status, disability and...

76 FR 37650 - Safety Zone; Northern California Annual Fireworks Events, Fourth of July Fireworks, South Lake...

Science.gov (United States)

2011-06-28

... Zone; Northern California Annual Fireworks Events, Fourth of July Fireworks, South Lake Tahoe Gaming... will enforce the safety zone for the annual Fourth of July Fireworks, South Lake Tahoe Gaming Alliance (Lights on the Lake Fireworks Display). This action is necessary to control vessel traffic and to ensure...

Molecular characterization of the Great Lakes viral hemorrhagic septicemia virus (VHSV isolate from USA

Directory of Open Access Journals (Sweden)

Vakharia Vikram N

2009-10-01

Full Text Available Abstract Background Viral hemorrhagic septicemia virus (VHSV is a highly contagious viral disease of fresh and saltwater fish worldwide. VHSV caused several large scale fish kills in the Great Lakes area and has been found in 28 different host species. The emergence of VHS in the Great Lakes began with the isolation of VHSV from a diseased muskellunge (Esox masquinongy caught from Lake St. Clair in 2003. VHSV is a member of the genus Novirhabdovirus, within the family Rhabdoviridae. It has a linear single-stranded, negative-sense RNA genome of approximately 11 kbp, with six genes. VHSV replicates in the cytoplasm and produces six monocistronic mRNAs. The gene order of VHSV is 3'-N-P-M-G-NV-L-5'. This study describes molecular characterization of the Great Lakes VHSV strain (MI03GL, and its phylogenetic relationships with selected European and North American isolates. Results The complete genomic sequences of VHSV-MI03GL strain was determined from cloned cDNA of six overlapping fragments, obtained by RT-PCR amplification of genomic RNA. The complete genome sequence of MI03GL comprises 11,184 nucleotides (GenBank GQ385941 with the gene order of 3'-N-P-M-G-NV-L-5'. These genes are separated by conserved gene junctions, with di-nucleotide gene spacers. The first 4 nucleotides at the termini of the VHSV genome are complementary and identical to other novirhadoviruses genomic termini. Sequence homology and phylogenetic analysis show that the Great Lakes virus is closely related to the Japanese strains JF00Ehi1 (96% and KRRV9822 (95%. Among other novirhabdoviruses, VHSV shares highest sequence homology (62% with snakehead rhabdovirus. Conclusion Phylogenetic tree obtained by comparing 48 glycoprotein gene sequences of different VHSV strains demonstrate that the Great Lakes VHSV is closely related to the North American and Japanese genotype IVa, but forms a distinct genotype IVb, which is clearly different from the three European genotypes. Molecular

Multiscale Terrain Analysis of Multibeam Bathymetry Data for Lake Trout Spawning Habitat Mapping in the Drummond Island Refuge, northern Lake Huron

Science.gov (United States)

Wattrus, N. J.; Binder, T.

2012-12-01

Until the 1950s, lake trout supported a valuable commercial fishery in the Great Lakes. The introduction of sea lamprey into the Great Lakes and overfishing resulted in the loss of most populations. Despite consistent stocking efforts since the 1960s, restoration of these populations has been slow. The reasons are numerous, but may be related to differences in the spawning behavior between hatchery and wild trout. A four-year study initiated in 2010, utilizes acoustic telemetry to characterize and compare the spawning behaviors of hatchery and wild lake trout in the Drummond Island Refuge in northern Lake Huron. In this project, the movement of tagged fish are monitored by an array of over 125 lake floor hydrophones during the fall spawning period. Fish behavior is overlaid over detailed bathymetric and substrate data and compared with environmental variables (e.g. water temperature, wind speed and direction, and wave height and direction) to develop a conceptual behavioral model. Sites suspected of being spawning sites based upon telemetry data are verified through the use of divers and trapping eggs and fry. Prior to this study, the factors that influenced how the spawning fish utilize the lake floor shoals have been poorly understood. Among the factors thought to impact spawning success were: bathymetry and substrate composition. Diver and telemetry data suggest that the fish(both hatchery raised and wild) are particularly attracted to rocky substrates and that fragment size is important. High resolution multibeam bathymetric surveys conducted in 2010 and 2011 have been used to characterize the shape and composition of the lake floor in the study area. Classification of the substrate is a labor intensive process requiring divers, drop cameras and sediment sampling. To improve this, the traditional approach has been to use supervised and unsupervised classification techniques that are based upon measured acoustic backscatter from an echosounder or sidescan sonar

Great Lakes Surface Ice Reports from U.S. Coast Guard

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Data consist of ice observations from U.S. Coast Guard vessels operating on the Great Lakes, and from Coast Guard shore stations reported via teletype messages and...

Food habits of diving ducks in the Great Lakes after the zebra mussel invasion

Science.gov (United States)

Custer, Christine M.; Custer, T.W.

1996-01-01

Zebra mussels (Dreissena polymorpha) invaded the Great Lakes in the mid-1980s and quickly reached high densities. The objective of this study was to determine current consumption of zebra mussels by waterfowl in the Great Lakes region. Feeding Lesser Scaups (Aythya affinis), Greater Scaups (A. marila), Canvasbacks (A. valisineria), Redheads (A. americana), Buffleheads (Bucephala albeola) and Common Goldeneyes (B. clangula) were collected in western Lake Erie and in Lake St. Clair between fall and spring, 1992-1993 to determine food habits. All 10 Redheads, 97% of Lesser Scaups, 83% of Goldeneyes, 60% of Buffleheads and 9% of Canvasbacks contained one or more zebra mussels in their upper gastrointestinal tracts. The aggregate percent of zebra mussels in the diet of Lesser Scaups was higher in Lake Erie (98.6%) than in Lake St. Clair (54.4%). Zebra mussels (aggregate percent) dominated the diet of Common Goldeneyes (79.2%) but not in Buffleheads (23.5%), Redheads (21%) or Canvasbacks (9%). Lesser Scaups from Lake Erie fed on larger zebra mussels ( = 10.7 i?? 0.66 mm SE) than did Lesser Scaups from Lake St. Clair ( = 4.4 i?? 0.22 mm). Lesser Scaups, Buffleheads and Common Goldeneyes from Lake Erie consumed zebra mussels of similar size.

Mercury and selenium contamination in waterbird eggs and risk to avian reproduction at Great Salt Lake, Utah

Science.gov (United States)

Ackerman, Joshua T.; Herzog, Mark P.; Hartman, Christopher A.; Isanhart, John P.; Herring, Garth; Vaughn, Sharon; Cavitt, John F.; Eagles-Smith, Collin A.; Browers, Howard; Cline, Chris; Vest, Josh

2015-01-01

The wetlands of the Great Salt Lake ecosystem are recognized regionally, nationally, and hemispherically for their importance as breeding, wintering, and migratory habitat for diverse groups of waterbirds. Bear River Migratory Bird Refuge is the largest freshwater component of the Great Salt Lake ecosystem and provides critical breeding habitat for more than 60 bird species. However, the Great Salt Lake ecosystem also has a history of both mercury and selenium contamination, and this pollution could reduce the health and reproductive success of waterbirds. The overall objective of this study was to evaluate the risk of mercury and selenium contamination to birds breeding within Great Salt Lake, especially at Bear River Migratory Bird Refuge, and to identify the waterbird species and areas at greatest risk to contamination. We sampled eggs from 33 species of birds breeding within wetlands of Great Salt Lake during 2010 ̶ 2012 and focused on American avocets (Recurvirostra americana), black-necked stilts (Himantopus mexicanus), Forster’s terns (Sterna forsteri), white-faced ibis (Plegadis chihi), and marsh wrens (Cistothorus palustris) for additional studies of the effects of contaminants on reproduction.

Investigation of spatial trends and neurochemical impacts of mercury in herring gulls across the Laurentian Great Lakes

Energy Technology Data Exchange (ETDEWEB)

Rutkiewicz, Jennifer [Department of Environmental Health Sciences, University of Michigan School of Public Health, 109 S. Observatory St, Ann Arbor, MI 48109 (United States); Scheuhammer, Anton; Crump, Doug; Jagla, Magdalena [Environment Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON K1A 0H3 (Canada); Basu, Niladri, E-mail: niladri@umich.ed [Department of Environmental Health Sciences, University of Michigan School of Public Health, 109 S. Observatory St, Ann Arbor, MI 48109 (United States)

2010-08-15

Herring gulls (Larus argentatus) bioaccumulate mercury (Hg) but it is unknown whether they are exposed at levels of neurological concern. Here we studied brain tissues from gulls at five Great Lakes colonies and one non-Great Lakes colony during spring of 2001 and 2003. Total brain Hg concentrations ranged from 0.14 to 2.0 {mu}g/g (dry weight) with a mean of 0.54 {mu}g/g. Gulls from Scotch Bonnet Island, on the easternmost edge of the Great Lakes, had significantly higher brain Hg than other colonies. No association was found between brain Hg concentration and [3H]-ligand binding to neurochemical receptors (N-methyl-D-aspartate, muscarinic cholinergic, nicotinic cholinergic) or nicotinic receptor {alpha}-7 relative mRNA expression as previously documented in other wildlife. In conclusion, spatial trends in Hg contamination exist in herring gulls across the Great Lakes basin, and herring gulls accumulate brain Hg but not at levels associated with sub-clinical neurochemical alterations. - Spatial trends in brain mercury exist in herring gulls across the Laurentian Great Lakes though levels are not associated with neurochemical biomarkers.

Investigation of spatial trends and neurochemical impacts of mercury in herring gulls across the Laurentian Great Lakes

International Nuclear Information System (INIS)

Rutkiewicz, Jennifer; Scheuhammer, Anton; Crump, Doug; Jagla, Magdalena; Basu, Niladri

2010-01-01

Herring gulls (Larus argentatus) bioaccumulate mercury (Hg) but it is unknown whether they are exposed at levels of neurological concern. Here we studied brain tissues from gulls at five Great Lakes colonies and one non-Great Lakes colony during spring of 2001 and 2003. Total brain Hg concentrations ranged from 0.14 to 2.0 μg/g (dry weight) with a mean of 0.54 μg/g. Gulls from Scotch Bonnet Island, on the easternmost edge of the Great Lakes, had significantly higher brain Hg than other colonies. No association was found between brain Hg concentration and [3H]-ligand binding to neurochemical receptors (N-methyl-D-aspartate, muscarinic cholinergic, nicotinic cholinergic) or nicotinic receptor α-7 relative mRNA expression as previously documented in other wildlife. In conclusion, spatial trends in Hg contamination exist in herring gulls across the Great Lakes basin, and herring gulls accumulate brain Hg but not at levels associated with sub-clinical neurochemical alterations. - Spatial trends in brain mercury exist in herring gulls across the Laurentian Great Lakes though levels are not associated with neurochemical biomarkers.

Chemical Evolution of Groundwater Near a Sinkhole Lake, Northern Florida: 1. Flow Patterns, Age of Groundwater, and Influence of Lake Water Leakage

Science.gov (United States)

Katz, Brian G.; Lee, Terrie M.; Plummer, L. Niel; Busenberg, Eurybiades

1995-06-01

Leakage from sinkhole lakes significantly influences recharge to the Upper Floridan aquifer in poorly confined sediments in northern Florida. Environmental isotopes (oxygen 18, deuterium, and tritium), chlorofluorocarbons (CFCs: CFC-11, CCl3F; CFC-12, CCl2F2; and CFC-113, C2Cl3F3), and solute tracers were used to investigate groundwater flow patterns near Lake Barco, a seepage lake in a mantled karst setting in northern Florida. Stable isotope data indicated that the groundwater downgradient from the lake contained 11-67% lake water leakage, with a limit of detection of lake water in groundwater of 4.3%. The mixing fractions of lake water leakage, which passed through organic-rich sediments in the lake bottom, were directly proportional to the observed methane concentrations and increased with depth in the groundwater flow system. In aerobic groundwater upgradient from Lake Barco, CFC-modeled recharge dates ranged from 1987 near the water table to the mid 1970s for water collected at a depth of 30 m below the water table. CFC-modeled recharge dates (based on CFC-12) for anaerobic groundwater downgradient from the lake ranged from the late 1950s to the mid 1970s and were consistent with tritium data. CFC-modeled recharge dates based on CFC-11 indicated preferential microbial degradation in anoxic waters. Vertical hydraulic conductivities, calculated using CFC-12 modeled recharge dates and Darcy's law, were 0.17, 0.033, and 0.019 m/d for the surficial aquifer, intermediate confining unit, and lake sediments, respectively. These conductivities agreed closely with those used in the calibration of a three-dimensional groundwater flow model for transient and steady state flow conditions.

Phallodrilus hallae, a new tubificid oligochaete from the St. Lawrence Great Lakes

Science.gov (United States)

Cook, David G.; Hiltunen, Jarl K.

1975-01-01

The predominantly marine tubificid genus Phallodrilus is defined, a key to its nine species constructed, and an illustrated description of Phallodrilus hallae n. sp. from the St. Lawrence Great Lakes presented. The species is distinguished from other members of the genus by its well-developed atrial musculature, extensions of which ensheath the posterior prostatic ducts.Phallodrilus hallae n. sp. is a small worm which is widely distributed in the sublittoral and profundal benthos of Lake Superior; lakewide it occurred in mean densities of 50 individuals per square metre. Available records indicate a more restricted distribution in Lake Huron and Georgian Bay. We suggest that P. hallae n. sp. is either a glaciomarine relict species, or that it entered the Great Lakes system at the time of the marine transgression of the St. Lawrence valley. The apparent restriction of P. hallae n. sp. to waters of high quality suggests that it may be a sensitive oligotrophic indicator species.

Understanding Obstacles to Peace in the Great Lakes Region ...

International Development Research Centre (IDRC) Digital Library (Canada)

Africa's Great Lakes region is home to violent and prolonged conflicts that cause a lot of suffering and block socioeconomic progress. Several initiatives are underway to bring peace to the region. But, most of these focus on specific countries and have not taken into account the interrelated and overlapping nature of the ...

Distribution and Modeled Transport of Plastic Pollution in the Great Lakes, the World's Largest Freshwater Resource

Directory of Open Access Journals (Sweden)

Rachel N. Cable

2017-07-01

Full Text Available Most plastic pollution originates on land. As such, freshwater bodies serve as conduits for the transport of plastic litter to the ocean. Understanding the concentrations and fluxes of plastic litter in freshwater ecosystems is critical to our understanding of the global plastic litter budget and underpins the success of future management strategies. We conducted a replicated field survey of surface plastic concentrations in four lakes in the North American Great Lakes system, the largest contiguous freshwater system on the planet. We then modeled plastic transport to resolve spatial and temporal variability of plastic distribution in one of the Great Lakes, Lake Erie. Triplicate surface samples were collected at 38 stations in mid-summer of 2014. Plastic particles >106 μm in size were quantified. Concentrations were highest near populated urban areas and their water infrastructure. In the highest concentration trawl, nearly 2 million fragments km−2 were found in the Detroit River—dwarfing previous reports of Great Lakes plastic abundances by over 4-fold. Yet, the accuracy of single trawl counts was challenged: within-station plastic abundances varied 0- to 3-fold between replicate trawls. In the smallest size class (106–1,000 μm, false positive rates of 12–24% were determined analytically for plastic vs. non-plastic, while false negative rates averaged ~18%. Though predicted to form in summer by the existing Lake Erie circulation model, our transport model did not predict a permanent surface “Lake Erie Garbage Patch” in its central basin—a trend supported by field survey data. Rather, general eastward transport with recirculation in the major basins was predicted. Further, modeled plastic residence times were drastically influenced by plastic buoyancy. Neutrally buoyant plastics—those with the same density as the ambient water—were flushed several times slower than plastics floating at the water's surface and exceeded the

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

Science.gov (United States)

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

1999-01-01

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

Organic geochemistry and brine composition in Great Salt, Mono, and Walker Lakes

Science.gov (United States)

Domagalski, Joseph L.; Orem, W.H.; Eugster, H.P.

1989-01-01

Samples of Recent sediments, representing up to 1000 years of accumulation, were collected from three closed basin lakes (Mono Lake, CA, Walker Lake, NV, and Great Salt Lake, UT) to assess the effects of brine composition on the accumulation of total organic carbon, the concentration of dissolved organic carbon, humic acid structure and diagenesis, and trace metal complexation. The Great Salt Lake water column is a stratified Na-Mg-Cl-SO4 brine with low alkalinity. Algal debris is entrained in the high density (1.132-1.190 g/cc) bottom brines, and in this region maximum organic matter decomposition occurs by anaerobic processes, with sulfate ion as the terminal electron acceptor. Organic matter, below 5 cm of the sediment-water interface, degrades at a very slow rate in spite of very high pore-fluid sulfate levels. The organic carbon concentration stabilizes at 1.1 wt%. Mono Lake is an alkaline (Na-CO3-Cl-SO4) system. The water column is stratified, but the bottom brines are of lower density relative to the Great Salt Lake, and sedimentation of algal debris is rapid. Depletion of pore-fluid sulfate, near l m of core, results in a much higher accumulation of organic carbon, approximately 6 wt%. Walker Lake is also an alkaline system. The water column is not stratified, and decomposition of organic matter occurs by aerobic processes at the sediment-water interface and by anaerobic processes below. Total organic carbon and dissolved organic carbon concentrations in Walker Lake sediments vary with location and depth due to changes in input and pore-fluid sulfate concentrations. Nuclear magnetic resonance studies (13C) of humic substances and dissolved organic carbon provide information on the source of the Recent sedimentary organic carbon (aquatic vs. terrestrial), its relative state of decomposition, and its chemical structure. The spectra suggest an algal origin with little terrestrial signature at all three lakes. This is indicated by the ratio of aliphatic to

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

Directory of Open Access Journals (Sweden)

Kevin Anthony Meyer

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

DECLINE AND EXTINCTION OF LAKE TROUT IN THE GREAT LAKES: CAN BIOLOGICAL INDICATORS HELP DIAGNOSE CAUSES, IDENTIFY REMEDIAL ACTIONS, AND PREDICT FUTURE CONDITIONS?

Science.gov (United States)

The lake trout, Salvelinus namaycush, is the predominant top predator native fish species of the Great Lakes. Lake trout are valued for commercial and recreational use in addition to their ecological importance. In the last half of the 20th century, population declines lead to vi...

Emergence of Viral hemorrhagic septicemia virus in the North American Great Lakes region is associated with low viral genetic diversity.

Science.gov (United States)

Thompson, Tarin M; Batts, William N; Faisal, Mohamed; Bowser, Paul; Casey, James W; Phillips, Kenneth; Garver, Kyle A; Winton, James; Kurath, Gael

2011-08-29

Viral hemorrhagic septicemia virus (VHSV) is a fish rhabdovirus that causes disease in a broad range of marine and freshwater hosts. The known geographic range includes the Northern Atlantic and Pacific Oceans, and recently it has invaded the Great Lakes region of North America. The goal of this work was to characterize genetic diversity of Great Lakes VHSV isolates at the early stage of this viral emergence by comparing a partial glycoprotein (G) gene sequence (669 nt) of 108 isolates collected from 2003 to 2009 from 31 species and at 37 sites. Phylogenetic analysis showed that all isolates fell into sub-lineage IVb within the major VHSV genetic group IV. Among these 108 isolates, genetic diversity was low, with a maximum of 1.05% within the 669 nt region. There were 11 unique sequences, designated vcG001 to vcG011. Two dominant sequence types, vcG001 and vcG002, accounted for 90% (97 of 108) of the isolates. The vcG001 isolates were most widespread. We saw no apparent association of sequence type with host or year of isolation, but we did note a spatial pattern, in which vcG002 isolates were more prevalent in the easternmost sub-regions, including inland New York state and the St. Lawrence Seaway. Different sequence types were found among isolates from single disease outbreaks, and mixtures of types were evident within 2 isolates from individual fish. Overall, the genetic diversity of VHSV in the Great Lakes region was found to be extremely low, consistent with an introduction of a new virus into a geographic region with previously naive host populations.

Emergence of viral hemorrhagic septicemia virus in the North American Great Lakes region is associated with low viral genetic diversity

Science.gov (United States)

Thompson, T.M.; Batts, W.N.; Faisal, M.; Bowser, P.; Casey, J.W.; Phillips, K.; Garver, K.A.; Winton, J.; Kurath, G.

2011-01-01

Viral hemorrhagic septicemia virus (VHSV) is a fish rhabdovirus that causes disease in a broad range of marine and freshwater hosts. The known geographic range includes the Northern Atlantic and Pacific Oceans, and recently it has invaded the Great Lakes region of North Ame­rica. The goal of this work was to characterize genetic diversity of Great Lakes VHSV isolates at the early stage of this viral emergence by comparing a partial glycoprotein (G) gene sequence (669 nt) of 108 isolates collected from 2003 to 2009 from 31 species and at 37 sites. Phylogenetic analysis showed that all isolates fell into sub-lineage IVb within the major VHSV genetic group IV. Among these 108 isolates, genetic diversity was low, with a maximum of 1.05% within the 669 nt region. There were 11 unique sequences, designated vcG001 to vcG011. Two dominant sequence types, vcG001 and vcG002, accounted for 90% (97 of 108) of the isolates. The vcG001 isolates were most widespread. We saw no apparent association of sequence type with host or year of isolation, but we did note a spatial pattern, in which vcG002 isolates were more prevalent in the easternmost sub-regions, including inland New York state and the St. Lawrence Seaway. Different sequence types were found among isolates from single disease outbreaks, and mixtures of types were evident within 2 isolates from ­individual fish. Overall, the genetic diversity of VHSV in the Great Lakes region was found to be extremely low, consistent with an introduction of a new virus into a geographic region with ­previously naïve host populations.

Assessment of biomass cogeneration in the Great Lakes region

International Nuclear Information System (INIS)

Burnham, M.; Easterly, J.L.

1994-01-01

Many biomass cogeneration facilities have successfully entered into power sales agreements with utilities across the country, often after overcoming various difficulties or barriers. Under a project sponsored by the Great Lakes Regional Biomass Energy Program of the U.S. Department of Energy, DynCorp sm-bullet Meridian has conducted a survey of biomass facilities in the seven Great Lakes states, selecting 10 facilities for case studies with at least one facility in each of the seven states. The purpose of the case studies was to address obstacles that biomass processors face in adding power production to their process heat systems, and to provide examples of successful strategies for entering into power sales agreements with utilities. The case studies showed that the primary incentives for investing in cogeneration and power sales are to reduce operating costs through improved biomass waste management and lower energy expenditures. Common barriers to cogeneration and power sales were high utility stand-by charges for unplanned outages and low utility avoided cost payments due to excess utility generation capacity

Milankovitch Modulation of the Ecosystem Dynamics of Fossil Great Lakes

Science.gov (United States)

Whiteside, J. H.; Olsen, P. E.; Eglinton, T. I.; Cornet, B.; Huber, P.; McDonald, N. G.

2008-12-01

Triassic and Early Jurassic lacustrine deposits of eastern North American rift basins preserve a spectacular record of precession-related Milankovitch forcing in the Pangean tropics. The abundant and well-preserved fossil fish assemblages from these great lakes demonstrate a sequence of cyclical changes that track the permeating hierarchy of climatic cycles. To detail ecosystem processes correlating with succession of fish communities, we measured bulk δ13Corg through a 100 ky series of Early Jurassic climatic precession-forced lake level cycles in the lower Shuttle Meadow Formation of the Hartford rift basin, CT. The deep-water phase of one of these cycles, the Bluff Head bed, has produced thousands of articulated fish. We observe fluctuations in the bulk δ13Corg of the cyclical strata that reflect differing degrees of lake water stratification, nutrient levels, and relative proportion of algal vs. plant derived organic matter that trace fish community changes. We can exclude extrinsic changes in the global exchangeable reservoirs as an origin of this variability because molecule-level δ13C of n-alkanes of plant leaf waxes from the same strata show no such variability. While at higher taxonomic levels the fish communities responded largely by sorting of taxa by environmental forcing, at the species level the holostean genus Semionotus responded by in situ evolution, and ultimately extinction, of a species flock. Fluctuations at the higher frequency, climatic precessional scale are mirrored at lower frequency, eccentricity modulated, scales, all following the lake-level hierarchical pattern. Thus, lacustrine isotopic ratios amplify the Milankovitch climate signal that was already intensified by sequelae of the end-Triassic extinctions. The degree to which the ecological structure of modern lakes responds to similar environmental cyclicity is largely unknown, but we suspect similar patterns and processes within the Neogene history of the East African great lakes

Regional groundwater-flow model of the Lake Michigan Basin in support of Great Lakes Basin water availability and use studies

Science.gov (United States)

Feinstein, D.T.; Hunt, R.J.; Reeves, H.W.

2010-01-01

A regional groundwater-flow model of the Lake Michigan Basin and surrounding areas has been developed in support of the Great Lakes Basin Pilot project under the U.S. Geological Survey's National Water Availability and Use Program. The transient 2-million-cell model incorporates multiple aquifers and pumping centers that create water-level drawdown that extends into deep saline waters. The 20-layer model simulates the exchange between a dense surface-water network and heterogeneous glacial deposits overlying stratified bedrock of the Wisconsin/Kankakee Arches and Michigan Basin in the Lower and Upper Peninsulas of Michigan; eastern Wisconsin; northern Indiana; and northeastern Illinois. The model is used to quantify changes in the groundwater system in response to pumping and variations in recharge from 1864 to 2005. Model results quantify the sources of water to major pumping centers, illustrate the dynamics of the groundwater system, and yield measures of water availability useful for water-resources management in the region. This report is a complete description of the methods and datasets used to develop the regional model, the underlying conceptual model, and model inputs, including specified values of material properties and the assignment of external and internal boundary conditions. The report also documents the application of the SEAWAT-2000 program for variable-density flow; it details the approach, advanced methods, and results associated with calibration through nonlinear regression using the PEST program; presents the water-level, drawdown, and groundwater flows for various geographic subregions and aquifer systems; and provides analyses of the effects of pumping from shallow and deep wells on sources of water to wells, the migration of groundwater divides, and direct and indirect groundwater discharge to Lake Michigan. The report considers the role of unconfined conditions at the regional scale as well as the influence of salinity on groundwater flow

Air pollution and environmental justice in the Great Lakes region

Science.gov (United States)

Comer, Bryan

While it is true that air quality has steadily improved in the Great Lakes region, air pollution remains at unhealthy concentrations in many areas. Research suggests that vulnerable and susceptible groups in society -- e.g., minorities, the poor, children, and poorly educated -- are often disproportionately impacted by exposure to environmental hazards, including air pollution. This dissertation explores the relationship between exposure to ambient air pollution (interpolated concentrations of fine particulate matter, PM2.5) and sociodemographic factors (race, housing value, housing status, education, age, and population density) at the Census block-group level in the Great Lakes region of the United States. A relatively novel approach to quantitative environmental justice analysis, geographically weighted regression (GWR), is compared with a simplified approach: ordinary least squares (OLS) regression. While OLS creates one global model to describe the relationship between air pollution exposure and sociodemographic factors, GWR creates many local models (one at each Census block group) that account for local variations in this relationship by allowing the value of regression coefficients to vary over space, overcoming OLS's assumption of homogeneity and spatial independence. Results suggest that GWR can elucidate patterns of potential environmental injustices that OLS models may miss. In fact, GWR results show that the relationship between exposure to ambient air pollution and sociodemographic characteristics is non-stationary and can vary geographically and temporally throughout the Great Lakes region. This suggests that regulators may need to address environmental justice issues at the neighborhood level, while understanding that the severity of environmental injustices can change throughout the year.

Comparing Physics Scheme Performance for a Lake Effect Snowfall Event in Northern Lower Michigan

Science.gov (United States)

Molthan, Andrew; Arnott, Justin M.

2012-01-01

High resolution forecast models, such as those used to predict severe convective storms, can also be applied to predictions of lake effect snowfall. A high resolution WRF model forecast model is provided to support operations at NWS WFO Gaylord, Michigan, using a 12 ]km and 4 ]km nested configuration. This is comparable to the simulations performed by other NWS WFOs adjacent to the Great Lakes, including offices in the NWS Eastern Region who participate in regional ensemble efforts. Ensemble efforts require diversity in initial conditions and physics configurations to emulate the plausible range of events in order to ascertain the likelihood of different forecast scenarios. In addition to providing probabilistic guidance, individual members can be evaluated to determine whether they appear to be biased in some way, or to better understand how certain physics configurations may impact the resulting forecast. On January 20 ]21, 2011, a lake effect snow event occurred in Northern Lower Michigan, with cooperative observing and CoCoRaHS stations reporting new snow accumulations between 2 and 8 inches and liquid equivalents of 0.1 ]0.25 h. The event of January 21, 2011 was particularly well observed, with numerous surface reports available. It was also well represented by the WRF configuration operated at NWS Gaylord. Given that the default configuration produced a reasonable prediction, it is used here to evaluate the impacts of other physics configurations on the resulting prediction of the primary lake effect band and resulting QPF. Emphasis here is on differences in planetary boundary layer and cloud microphysics parameterizations, given their likely role in determining the evolution of shallow convection and precipitation processes. Results from an ensemble of seven microphysics schemes and three planetary boundary layer schemes are presented to demonstrate variability in forecast evolution, with results used in an attempt to improve the forecasts in the 2011 ]2012

Spatial distribution of pelagic fish larvae in the northern main basin of Lake Huron

Science.gov (United States)

Roseman, Edward F.; O'Brien, Timothy P.

2013-01-01

Larval fish occurrence in inshore and offshore zones in the northern main basin of Lake Huron was assessed during 2007 as part of a larger ecological examination of Lake Huron foodwebs and habitats. Day and night collections using neuston and conical nets at inshore (1.5–15 m depths) and offshore (37 and 91 m depths) locations at De Tour and Hammond Bay to assess the abundance, phenology, and spatial distribution of pelagic ichthyoplankton during spring and early summer were made. In general, densities of larval fishes were higher at De Tour than Hammond Bay during daytime neuston net collections, with the exception of Longnose Sucker, which were only collected at Hammond Bay. Lake Whitefish, Burbot, and Rainbow Smelt dominated inshore catches in early spring with Cisco, Deepwater Sculpin, Emerald Shiner, Bloater, Slimy Sculpin, Ninespine Stickleback, and Yellow Perch larvae also collected.Nighttime nearshore and offshore sampling revealed that Rainbow Smelt and Burbot larvae were present in relatively high abundances compared to inshore densities. Concentrations of larvae of deepwater demersal fishes such as Lake Whitefish and Deepwater Sculpin suggest that inshore zones in northern Lake Huron are important nursery habitats emphasizing a critical production and recruitment linkage between inshore and deepwater zones.

Petrology of the Fort Smith - Great Slave Lake radiometric high near Pilot Lake, N.W.T

International Nuclear Information System (INIS)

Burwash, R.A.; Cape, D.F.

1981-01-01

Near Pilot Lake, the east boundary of the Fort Smith - Great Slave Lake radiometric high coincides with the contact of a well-foliated, porphyroblastic microcline-plagioclase-quartz-garnet-biotite gneiss (Pilot Lake Gneiss) with a hybrid assemblage of quartzite, mica schist, garnet-cordierite gneiss, and minor amphibolite (Variable Paragneiss). Anomalously high concentrations of uranium and thorium are associated with mafic-rich, lenticular bodies with a mineral assemblage biotite + monazite + zircon + ilmenite + hematite +- plagioclase +- quartz, within both the Variable Paragneiss and the Pilot Lake Gneiss. Corundum and spinel occur in the mafic lenses and sillimanite, kyanite, and hypersthene in other inclusions of the Pilot Lake Gneiss. The ilmenite-magnetite--monazite-zircon-apatite assemblage is interpreted as a 'black sand' concentration in a clastic sedimentary sequence subsequently metamorphosed by a regional granulite facies event. A granite pluton intruded during the same orogenic cycle assimilated the clastic metasedimentary rocks containing black sand interlayers, becoming enriched in thorium from the monazite. A second metamorphic event at lower P-T conditions, accompanied by strong cataclasis, developed the texture of the Pilot Lake Gneiss as now observed. Shearing within the gneiss locally concentrated hematite + quartz + uranium. Regional tectonic extrapolations suggest that the pyroxene granulite event was Kenoran and the later amphibolite event Hudsonian. (author)

Policies and practices of beach monitoring in the Great Lakes, USA: a critical review

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Nevers, Meredith B.; Whitman, Richard L.

2010-01-01

Beaches throughout the Great Lakes are monitored for fecal indicator bacteria (typically Escherichia coli) in order to protect the public from potential sewage contamination. Currently, there is no universal standard for sample collection and analysis or results interpretation. Monitoring policies are developed by individual beach management jurisdictions, and applications are highly variable across and within lakes, states, and provinces. Extensive research has demonstrated that sampling decisions for time, depth, number of replicates, frequency of sampling, and laboratory analysis all influence the results outcome, as well as calculations of the mean and interpretation of the results in policy decisions. Additional shortcomings to current monitoring approaches include appropriateness and reliability of currently used indicator bacteria and the overall goal of these monitoring programs. Current research is attempting to circumvent these complex issues by developing new tools and methods for beach monitoring. In this review, we highlight the variety of sampling routines used across the Great Lakes and the extensive body of research that challenges comparisons among beaches. We also assess the future of Great Lakes monitoring and the advantages and disadvantages of establishing standards that are evenly applied across all beaches.

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

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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.

Great Lakes Regional Biomass Energy Program

International Nuclear Information System (INIS)

Kuzel, F.

1993-01-01

The Great Lakes Regional Biomass Energy Program (GLRBEP) was initiated September, 1983, with a grant from the Office of Energy Efficiency and Renewable Energy of the US Department of Energy (DOE). The program provides resources to public and private organizations in the Great Lakes region to increase the utilization and production of biomass fuels. The objectives of the GLRBEP are to: (1) improve the capabilities and effectiveness of biomass energy programs in the state energy offices; (2) assess the availability of biomass resources for energy in light of other competing needs and uses; (3) encourage private sector investments in biomass energy technologies; (4) transfer the results of government-sponsored biomass research and development to the private sector; (5) eliminate or reduce barriers to private sector use of biomass fuels and technology; (6) prevent or substantially mitigate adverse environmental impacts of biomass energy use. The Program Director is responsible for the day-to-day activities of the GLRBEP and for implementing program mandates. A 40 member Technical Advisory Committee (TAC) sets priorities and recommends projects. The governor of each state in the region appoints a member to the Steering Council, which acts on recommendations of the TAC and sets basic program guidelines. The GLRBEP is divided into three separate operational elements. The State Grants component provides funds and direction to the seven state energy offices in the region to increase their capabilities in biomass energy. State-specific activities and interagency programs are emphasized. The Subcontractor component involves the issuance of solicitations to undertake projects that address regional needs, identified by the Technical Advisory Committee. The Technology Transfer component includes the development of nontechnical biomass energy publications and reports by Council staff and contractors, and the dissemination of information at conferences, workshops and other events

Weather and eared grebe winter migration near the Great Salt Lake, Utah

Science.gov (United States)

Williams, Augusta A.; Laird, Neil F.

2018-03-01

This study provides insight from the use of weather radar observations to understand the characteristics of the eared grebe migration near the Great Salt Lake (GSL) and provides unique information on weather conditions connected to these migration events. Doppler weather radar measurements from the Salt Lake City, Utah WSR-88D radar site (KMTX), along with meteorological surface and rawinsonde data, were used to identify and examine 281 eared grebe migration events across 15 winters from 1997/1998 through 2011/2012. An average of about 19 migration events occurred each winter with considerable interannual variability, as well as large variance in the spatial area and number of birds departing the GSL during each event. The migration events typically occurred during clear sky conditions in the presence of surface high pressure and colder than average surface temperatures. Migration events began 55 min after sunset, on average across the winter seasons, and in one case we demonstrate that an extended, nonstop flight was initiated of the departing eared grebes to northern Mexico. Eared grebes leaving the GSL largely flew above the freezing level with a mean northerly tailwind at flight altitude of 3.1 m s-1 and a westerly, cross-flight wind of 5.0 m s-1 while having an average flight speed at cruising altitude of 16.9 m s-1, or 61 km h-1. In addition to determining the variability of meteorological conditions during migration events across the 15 winters, atmospheric conditions during the largest migration event observed are presented and discussed.

350 Years of Fire-Climate-Human Interactions in a Great Lakes Sandy Outwash Plain

Directory of Open Access Journals (Sweden)

Richard P. Guyette

2016-08-01

Full Text Available Throughout much of eastern North America, quantitative records of historical fire regimes and interactions with humans are absent. Annual resolution fire scar histories provide data on fire frequency, extent, and severity, but also can be used to understand fire-climate-human interactions. This study used tree-ring dated fire scars from red pines (Pinus resinosa at four sites in the Northern Sands Ecological Landscapes of Wisconsin to quantify the interactions among fire occurrence and seasonality, drought, and humans. New methods for assessing the influence of human ignitions on fire regimes were developed. A temporal and spatial index of wildland fire was significantly correlated (r = 0.48 with drought indices (Palmer Drought Severity Index, PDSI. Fire intervals varied through time with human activities that included early French Jesuit missions, European trade (fur, diseases, war, and land use. Comparisons of historical fire records suggest that annual climate in this region has a broad influence on the occurrence of fire years in the Great Lakes region.

Environmentally relevant chemical mixtures of concern in waters of United States tributaries to the Great Lakes

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Elliott, Sarah M.; Brigham, Mark E.; Kiesling, Richard L.; Schoenfuss, Heiko L.; Jorgenson, Zachary G.

2018-01-01

The North American Great Lakes are a vital natural resource that provide fish and wildlife habitat, as well as drinking water and waste assimilation services for millions of people. Tributaries to the Great Lakes receive chemical inputs from various point and nonpoint sources, and thus are expected to have complex mixtures of chemicals. However, our understanding of the co‐occurrence of specific chemicals in complex mixtures is limited. To better understand the occurrence of specific chemical mixtures in the US Great Lakes Basin, surface water from 24 US tributaries to the Laurentian Great Lakes was collected and analyzed for diverse suites of organic chemicals, primarily focused on chemicals of concern (e.g., pharmaceuticals, personal care products, fragrances). A total of 181 samples and 21 chemical classes were assessed for mixture compositions. Basin wide, 1664 mixtures occurred in at least 25% of sites. The most complex mixtures identified comprised 9 chemical classes and occurred in 58% of sampled tributaries. Pharmaceuticals typically occurred in complex mixtures, reflecting pharmaceutical‐use patterns and wastewater facility outfall influences. Fewer mixtures were identified at lake or lake‐influenced sites than at riverine sites. As mixture complexity increased, the probability of a specific mixture occurring more often than by chance greatly increased, highlighting the importance of understanding source contributions to the environment. This empirically based analysis of mixture composition and occurrence may be used to focus future sampling efforts or mixture toxicity assessments. 

Regional versus local influences on lead and cadmium loading to the Great Lakes region

Energy Technology Data Exchange (ETDEWEB)

Yohn, S.; Long, D.; Fett, J.; Patino, L. [Michigan State University, East Lansing, MI (United States). Dept. of Geological Science

2004-07-01

Environmental legislation has reduced the anthropogenic loadings of Pb and Cd to the Great Lakes region over the past 3 decades. However, the accumulation rates of these metals still remain above background values. Because environmental legislation was targeted at major sources (e.g., Pb in gasoline) whose influence on the environment was on a regional scale, local sources (e.g., watershed scale) for the metals may now play a more significant role. The relative importance of regional versus local scale influences on metal inputs to the environment is poorly understood. In this study, sediment chronologies of Pb and Cd were examined from 12 inland lakes that cover the broad geographic area of the State of Michigan. These chronologies were compared temporally and spatially and to watershed population densities and metal production records to gain an understanding of local and regional influences on metal inputs to the Great Lakes region. Results show that anthropogenic Pb loading during the 1930s and 1970s was dominated by regional sources. such as coal burning and use of leaded gasoline. Current loadings are now more related to local influences such as watershed population densities, rather than atmospheric deposition. Anthropogenic Cd loadings to the Great Lakes region have been dominated by both regional and local sources over time. Lead may also have shown the influence of local sources over time, if the influence of emissions from gasoline had not been present. This work shows that Pb and Cd loadings in the Great Lakes region are strongly related to watershed population densities; however, the specific sources and pathways for the metal cycling are unclear.

A conceptual model to facilitate amphibian conservation in the northern Great Plains

Science.gov (United States)

Mushnet, David M.; Euliss, Ned H.; Stockwell, Craig A.

2012-01-01

As pressures on agricultural landscapes to meet worldwide resource needs increase, amphibian populations face numerous threats including habitat destruction, chemical contaminants, disease outbreaks, wetland sedimentation, and synergistic effects of these perturbations. To facilitate conservation planning, we developed a conceptual model depicting elements critical for amphibian conservation in the northern Great Plains. First, we linked upland, wetland, and landscape features to specific ecological attributes. Ecological attributes included adult survival; reproduction and survival to metamorphosis; and successful dispersal and recolonization. Second, we linked ecosystem drivers, ecosystem stressors, and ecological effects of the region to each ecological attribute. Lastly, we summarized information on these ecological attributes and the drivers, stressors, and effects that work in concert to influence the maintenance of viable and genetically diverse amphibian populations in the northern Great Plains. While our focus was on the northern Great Plains, our conceptual model can be tailored to other geographic regions and taxa.

Democratic Republic of Congo A Fertile Ground for Instability in the Great Lakes Region States

Science.gov (United States)

2017-06-09

ravaged by a brutal armed conflict. In comparison to the three past presidents, Joseph Kabila has managed to restore political stability and calm to much...DEMOCRATIC REPUBLIC OF CONGO-A FERTILE GROUND FOR INSTABILITY IN THE GREAT LAKES REGION STATES A thesis presented to the Faculty of...From - To) AUG 2016 – JUNE 2017 4. TITLE AND SUBTITLE Democratic Republic of Congo-A Fertile Ground for Instability in the Great Lakes Region

Occurrence and distribution of fecal indicator bacteria and gene markers of pathogenic bacteria in Great Lakes tributaries, March-October 2011

Science.gov (United States)

Brennan, Angela K.; Johnson, Heather E.; Totten, Alexander R.; Duris, Joseph W.

2015-01-01

From March through October 2011, the U.S. Geological Survey (USGS), conducted a study to determine the frequency of occurrence of pathogen gene markers and densities of fecal indicator bacteria (FIB) in 22 tributaries to the Great Lakes. This project was funded as part of the Great Lakes Restoration Initiative (GLRI) and included sampling at 22 locations throughout 6 states that border the Great Lakes.

Regional Climate Models as a Tool for Assessing Changes in the Laurentian Great Lakes Net Basin Supply

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Music, B.; Mailhot, E.; Nadeau, D.; Irambona, C.; Frigon, A.

2017-12-01

Over the last decades, there has been growing concern about the effects of climate change on the Great Lakes water supply. Most of the modelling studies focusing on the Laurentian Great Lakes do not allow two-way exchanges of water and energy between the atmosphere and the underlying surface, and therefore do not account for important feedback mechanisms. Moreover, energy budget constraint at the land surface is not usually taken into account. To address this issue, several recent climate change studies used high resolution Regional Climate Models (RCMs) for evaluating changes in the hydrological regime of the Great Lakes. As RCMs operate on the concept of water and energy conservation, an internal consistency of the simulated energy and water budget components is assured. In this study we explore several recently generated Regional Climate Model (RCM) simulations to investigate the Great Lakes' Net Basin Supply (NBS) in a changing climate. These include simulations of the Canadian Regional Climate Model (CRCM5) supplemented by simulations from several others RCMs participating to the North American CORDEX project (CORDEX-NA). The analysis focuses on the NBS extreme values under nonstationary conditions. The results are expected to provide useful information to the industries in the Great Lakes that all need to include accurate climate change information in their long-term strategy plans to better anticipate impacts of low and/or high water levels.

Fringe benefit: Value of restoring coastal wetlands for Great Lakes fisheries

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Fishery support is recognized as a valuable ecosystem service provided by Great Lakes coastal wetlands, but it is challenging to quantify because multiple species and habitats are involved. Recent studies indicate that coastal wetland area is proportional to fishery harvest among...

Ecosystem Services in the Great Lakes – Results of a Summit

Science.gov (United States)

A comprehensive inventory of ecosystem services across the entire Great Lakes basin is currently lacking and is needed to make informed management decisions. A greater appreciation and understanding of ecosystem services, including both use and non-use services, may have avoided ...

State-of-the-art techniques for inventory of Great Lakes aquatic habitats and resources

Science.gov (United States)

Edsall, Thomas A.; Brock, R.H.; Bukata, R.P.; Dawson, J.J.; Horvath, F.J.; Busch, W.-Dieter N.; Sly, Peter G.

1992-01-01

This section of the Classification and Inventory of Great Lakes Aquatic Habitat report was prepared as a series of individually authored contributions that describe, in various levels of detail, state-of-the-art techniques that can be used alone or in combination to inventory aquatic habitats and resources in the Laurentian Great Lakes system. No attempt was made to review and evaluate techniques that are used routinely in limnological and fisheries surveys and inventories because it was felt that users of this document would be familiar with them.

Mercury and water level fluctuations in lakes of northern Minnesota

Science.gov (United States)

Larson, James H.; Maki, Ryan P; Christensen, Victoria G.; Sandheinrich, Mark B.; LeDuc, Jaime F.; Kissane, Claire; Knights, Brent C.

2017-01-01

Large lake ecosystems support a variety of ecosystem services in surrounding communities, including recreational and commercial fishing. However, many northern temperate fisheries are contaminated by mercury. Annual variation in mercury accumulation in fish has previously been linked to water level (WL) fluctuations, opening the possibility of regulating water levels in a manner that minimizes or reduces mercury contamination in fisheries. Here, we compiled a long-term dataset (1997-2015) of mercury content in young-of-year Yellow Perch (Perca flavescens) from six lakes on the border between the U.S. and Canada and examined whether mercury content appeared to be related to several metrics of WL fluctuation (e.g., spring WL rise, annual maximum WL, and year-to-year change in maximum WL). Using simple correlation analysis, several WL metrics appear to be strongly correlated to Yellow Perch mercury content, although the strength of these correlations varies by lake. We also used many WL metrics, water quality measurements, temperature and annual deposition data to build predictive models using partial least squared regression (PLSR) analysis for each lake. These PLSR models showed some variation among lakes, but also supported strong associations between WL fluctuations and annual variation in Yellow Perch mercury content. The study lakes underwent a modest change in WL management in 2000, when winter WL minimums were increased by about 1 m in five of the six study lakes. Using the PLSR models, we estimated how this change in WL management would have affected Yellow Perch mercury content. For four of the study lakes, the change in WL management that occurred in 2000 likely reduced Yellow Perch mercury content, relative to the previous WL management regime.

Turbidity as a factor in the decline of Great Lakes fishes with special reference to Lake Erie

Science.gov (United States)

Van Oosten, John

1948-01-01

Fish live and thrive in water with turbidities that range above 400 p.p.m. and average 200 p.p.m. The waters of the Great Lakes usually are clear except in Lake Erie where the turbidities of the inshore areas averaged 37 p.p.m.; the turbidities of the offshore waters averaged less. Lake Erie waters were no clearer 50 years ago than they are now. In fact, the turbidity values are less now than they were in the earlier years; the annual average of the inshore waters dropped from 44 p.p.m. before 1930 to 32 p.p.m. in 1930 and later, and the April-May values decreased from 72 p.p.m. to 46 p.p.m. Any general decline in the Lake Erie fishes cannot be attributed to increased turbidities. Furthermore, these turbidities averaged well below 100 p.p.m. and, therefore, were too low to affect fishes adversely.

Changes in lake levels, salinity and the biological community of Great Salt Lake (Utah, USA), 1847-1987

Science.gov (United States)

Stephens, D.W.

1990-01-01

Great Salt Lake is the fourth largest terminal lake in the world, with an area of about 6000 square kilometers at its historic high elevation. Since its historic low elevation of 1277.52 meters in 1963, the lake has risen to a new historic high elevation of 1283.77 meters in 1986-1987, a net increase of about 6.25 meters. About 60 percent of this increase, 3.72 meters, has occurred since 1982 in response to greater than average precipitation and less than average evaporation. Variations in salinity have resulted in changes in the composition of the aquatic biological community which consists of bacteria, protozoa, brine shrimp and brine flies. These changes were particularly evident following the completion of a causeway in 1959 which divided the lake. Subsequent salinities in the north part of the lake have ranged from 16 to 29 percent and in the south part from 6 to 28 percent. Accompanying the rise in lake elevation from 1982 to 1987 have been large decreases in salinity of both parts of the lake. This has resulted in changes in the biota from obligate halophiles, such as Dunaliella salina and D. viridis, to opportunistic forms such as a blue-green alga (Nodularia spumigena). The distribution and abundance of brine shrimp (Artemia salina) in the lake also have followed closely the salinity. In 1986, when the salinity of the south part of the lake was about 6 percent, a population of brackish-water killifish (Lucania parva) was observed along the shore near inflow from a spring. ?? 1990 Kluwer Academic Publishers.

Biological and ecological science for Wisconsin—A Great Lakes and Rivers State

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,

2018-03-06

Wisconsin and natural resources go hand-in-hand. Tourism, which generates $19 billion annually and sustains about 200,000 jobs, depends on an abundance of lakes, rivers, shorelines, and woodlands for fishing, hunting, boating, and other outdoor recreation. Rivers and floodplains in the Upper Mississippi Basin, including the Mississippi River, are part of a five-State corridor that generates more than $300 billion annually and sustains millions of manufacturing, tourism, transportation, and agricultural jobs. Wisconsin also is a Great Lakes State with more than 800 miles of shoreline, and the fisheries of lakes Superior and Michigan deliver $185 million annually and provide thousands of jobs.

Trophic ecology of largemouth bass and northern pike in allopatric and sympatric assemblages in northern boreal lakes

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Soupir, Craig A.; Brown, Michael L.; Kallemeyn, Larry W.

2000-01-01

Largemouth bass (Micropterus salmoides) and northern pike (Esox lucius) are top predators in the food chain in most aquatic environments that they occupy; however, limited information exists on species interactions in the northern reaches of largemouth bass distribution. We investigated the seasonal food habits of allopatric and sympatric assemblages of largemouth bass and northern pike in six interior lakes within Voyageurs National Park, Minnesota. Percentages of empty stomachs were variable for largemouth bass (38-54%) and northern pike (34.7-66.7%). Fishes (mainly yellow perch, Perca flavescens) comprised greater than 60% (mean percent mass, MPM) of the northern pike diet during all seasons in both allopatric and sympatric assemblages. Aquatic insects (primarily Odonata and Hemiptera) were important in the diets of largemouth bass in all communities (0.0-79.7 MPM). Although largemouth bass were observed in the diet of northern pike, largemouth bass apparently did not prey on northern pike. Seasonal differences were observed in the proportion of aquatic insects (P = 0.010) and fishes (P = 0.023) in the diets of northern pike and largemouth bass. Based on three food categories, jackknifed classifications correctly classified 77 and 92% of northern pike and largemouth bass values, respectively. Percent resource overlap values were biologically significant (greater than 60%) during at least one season in each sympatric assemblage, suggesting some diet overlap.

A synthesis of rates and controls on elemental mercury evasion in the Great Lakes Basin

International Nuclear Information System (INIS)

Denkenberger, Joseph S.; Driscoll, Charles T.; Branfireun, Brian A.; Eckley, Chris S.; Cohen, Mark; Selvendiran, Pranesh

2012-01-01

Rates of surface-air elemental mercury (Hg 0 ) fluxes in the literature were synthesized for the Great Lakes Basin (GLB). For the majority of surfaces, fluxes were net positive (evasion). Digital land-cover data were combined with representative evasion rates and used to estimate annual Hg 0 evasion for the GLB (7.7 Mg/yr). This value is less than our estimate of total Hg deposition to the area (15.9 Mg/yr), suggesting the GLB is a net sink for atmospheric Hg. The greatest contributors to annual evasion for the basin are agricultural (∼55%) and forest (∼25%) land cover types, and the open water of the Great Lakes (∼15%). Areal evasion rates were similar across most land cover types (range: 7.0–21.0 μg/m 2 -yr), with higher rates associated with urban (12.6 μg/m 2 -yr) and agricultural (21.0 μg/m 2 -yr) lands. Uncertainty in these estimates could be partially remedied through a unified methodological approach to estimating Hg 0 fluxes. - Highlights: ► Considerable variability exists across spatial/temporal scales in Hg 0 evasion rates. ► Methodological approaches vary for estimating and reporting gaseous Hg 0 fluxes. ► Hg 0 evasion from the Great Lakes Basin is estimated at 7.7 Mg/yr (10.2 μg/m 2 -yr). ► Hg flux estimates suggest region is a net sink for atmospheric Hg. ► 95% of Hg 0 evasion in the region is from agriculture, forest, and the Great Lakes. - A synthesis of Hg evasion was conducted and this information was used to develop an estimate of Hg evasion for the Great Lakes Basin.

Water Availability and Use Pilot-A multiscale assessment in the U.S. Great Lakes Basin

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Reeves, Howard W.

2011-01-01

Beginning in 2005, water availability and use were assessed for the U.S. part of the Great Lakes Basin through the Great Lakes Basin Pilot of a U.S. Geological Survey (USGS) national assessment of water availability and use. The goals of a national assessment of water availability and use are to clarify our understanding of water-availability status and trends and improve our ability to forecast the balance between water supply and demand for future economic and environmental uses. This report outlines possible approaches for full-scale implementation of such an assessment. As such, the focus of this study was on collecting, compiling, and analyzing a wide variety of data to define the storage and dynamics of water resources and quantify the human demands on water in the Great Lakes region. The study focused on multiple spatial and temporal scales to highlight not only the abundant regional availability of water but also the potential for local shortages or conflicts over water. Regional studies provided a framework for understanding water resources in the basin. Subregional studies directed attention to varied aspects of the water-resources system that would have been difficult to assess for the whole region because of either data limitations or time limitations for the project. The study of local issues and concerns was motivated by regional discussions that led to recent legislative action between the Great Lakes States and regional cooperation with the Canadian Great Lakes Provinces. The multiscale nature of the study findings challenges water-resource managers and the public to think about regional water resources in an integrated way and to understand how future changes to the system-driven by human uses, climate variability, or land-use change-may be accommodated by informed water-resources management.

Meteotsunamis in the Great Lakes and Investigation into the May 27, 2012 Event on Lake Erie

Science.gov (United States)

Anderson, E. J.; Bechle, A.; Wu, C. H.; Schwab, D. J.; Mann, G.

2016-02-01

Meteotsunami events have been documented in several countries around the world in the coastal ocean, semi-enclosed basins, and in the Great Lakes. In particular, investigations in the Great Lakes have raised the issue of dangers posed by enclosed basins due to the reflection and interaction of meteotsunami waves, in which the destructive waves can arrive several hours after the atmospheric disturbance has passed. This disassociation in time and space between the atmospheric disturbance and resultant meteotsunami wave can pose a significant threat to the public. In a recent event on May 27, 2012, atmospheric conditions gave rise to two convective systems that generated a series of waves in the meteotsunami band on Lake Erie. The resulting waves swept three swimmers a half-mile offshore, inundated a marina, and may have led to a capsized boat along the southern shoreline. Examination of the observed conditions shows that these events occurred at a time between the arrivals of these two storm systems when atmospheric conditions were relatively calm but water level displacements were at their greatest. In this work, we attempt to explain the processes that led to these conditions through a combination of atmospheric and hydrodynamic modeling and an analysis of the observed radial velocities associated with the meteotsunami-inducing front. Results from a high-resolution atmospheric model and hydrodynamic model reveal that the formation of these destructive waves resulted from a combination of wave reflection, focusing, and edge waves that impacted the southern shore of Lake Erie. This event illustrates the unique danger posed by temporal lags between the inducing atmospheric conditions and resulting dangerous nearshore wave conditions.

Decadal trends and common dynamics of the bio-optical and thermal characteristics of the African Great Lakes.

Directory of Open Access Journals (Sweden)

Steven Loiselle

Full Text Available The Great Lakes of East Africa are among the world's most important freshwater ecosystems. Despite their importance in providing vital resources and ecosystem services, the impact of regional and global environmental drivers on this lacustrine system remains only partially understood. We make a systematic comparison of the dynamics of the bio-optical and thermal properties of thirteen of the largest African lakes between 2002 and 2011. Lake surface temperatures had a positive trend in all Great Lakes outside the latitude of 0° to 8° south, while the dynamics of those lakes within this latitude range were highly sensitive to global inter-annual climate drivers (i.e. El Niño Southern Oscillation. Lake surface temperature dynamics in nearly all lakes were found to be sensitive to the latitudinal position of the Inter Tropical Convergence Zone. Phytoplankton dynamics varied considerably between lakes, with increasing and decreasing trends. Intra-lake differences in both surface temperature and phytoplankton dynamics occurred for many of the larger lakes. This inter-comparison of bio-optical and thermal dynamics provides new insights into the response of these ecosystems to global and regional drivers.

Long-term management impacts on carbon storage in Lake States forests

Science.gov (United States)

Matthew Powers; Randall Kolka; Brian Palik; Rachel McDonald; Martin. Jurgensen

2011-01-01

We examined carbon storage following 50+ years of forest management in two long-term silvicultural studies in red pine and northern hardwood ecosystems of North America’s Great Lakes region. The studies contrasted various thinning intensities (red pine) or selection cuttings, shelterwoods, and diameter-limit cuttings (northern hardwoods) to unmanaged controls of...

Nourishment of perched sand dunes and the issue of erosion control in the Great Lakes

Science.gov (United States)

Marsh, William M.

1990-09-01

Although limited in coverage, perched sand dunes situated on high coastal bluffs are considered the most prized of Great Lakes dunes. Grand Sable Dunes on Lake Superior and Sleeping Bear Dunes on Lake Michigan are featured attractions of national lakeshores under National Park Service management. The source of sand for perched dunes is the high bluff along their lakeward edge. As onshore wind crosses the bluff, flow is accelerated upslope, resulting in greatly elevated levels of wind stress over the slope brow. On barren, sandy bluffs, wind erosion is concentrated in the brow zone, and for the Grand Sable Bluff, it averaged 1 m3/yr per linear meter along the highest sections for the period 1973 1983. This mechanism accounts for about 6,500 m3 of sand nourishment to the dunefield annually and clearly has been the predominant mechanism for the long-term development of the dunefield. However, wind erosion and dune nourishment are possible only where the bluff is denuded of plant cover by mass movements and related processes induced by wave erosion. In the Great Lakes, wave erosion and bluff retreat vary with lake levels; the nourishment of perched dunes is favored by high levels. Lake levels have been relatively high for the past 50 years, and shore erosion has become a major environmental issue leading property owners and politicians to support lake-level regulation. Trimming high water levels could reduce geomorphic activity on high bluffs and affect dune nourishment rates. Locally, nourishment also may be influenced by sediment accumulation associated with harbor protection facilities and by planting programs aimed at stabilizing dunes.

An Overview of Sediment Organic Matter Records of Human Eutrophication in the Laurentian Great Lakes Region

Energy Technology Data Exchange (ETDEWEB)

Meyers, Philip A. [University of Michigan, Department of Geological Sciences (United States)], E-mail: pameyers@umich.ed

2006-12-15

The isotopic and molecular compositions of organic matter buried in lake sediments provide information that helps to reconstruct past environmental conditions and to assess impacts of humans on local ecosystems. This overview of sedimentary records from the North American Great Lakes region describes examples of applications of organic geochemistry to paleolimnological reconstructions. These lakes experienced a succession of human-induced environmental changes that started after completion of the Erie Canal in 1825. Agricultural deforestation in the mid-nineteenth century released soil nutrients that increased algal productivity and caused an associated increase in algal biomarkers in sediment records. Eutrophication that accompanied magnified delivery of municipal nutrients to the lakes in the 1960s and 1970s created excursions to less negative {delta}{sup 13}C values in sediment organic matter. Increased organic carbon mass accumulation rates mirror the isotopic evidence of eutrophication in the Great Lakes.

Quantitative interpretation of great lakes remote sensing data

International Nuclear Information System (INIS)

Shook, D.F.; Salzman, J.; Svehla, R.A.; Gedney, R.T.

1980-01-01

Remote sensing has been applied in the past to the surveillance of Great Lakes water quality, but it has been only partially successful because of the completely empirical approach taken in relating the multispectral scanning data at visible and near-infrared wavelengths to water parameters. Any remote sensing approach using water color information must take into account (1) the existence of many different organic and inorganic species throughtout the Greak Lakes, (2) the occurrence of a mixture of species in most locations, and (3) spatial (inter- and interlake as well as vertical) variations in types and concentrations of species. The radiative transfer model provides a potential method for an orderly analysis of remote sensing data and a physical basis for developing quantitative algorithms. Predictions and field measurements of volume reflectances are presented which clearly show the advantage of using a radiative transfer model. Spectral absorptance and backscattering coefficients for two inorganic sediments are reported

Oligocene paleogeography of the northern Great Plains and adjacent mountains

International Nuclear Information System (INIS)

Seeland, D.

1985-01-01

Early Oligocene paleogeography of the northern Great Plains and adjacent mountains is inferred in part from published surface and subsurface studies of the pre-Oligocene surface. These studies are combined with published and unpublished information on clast provenance, crossbedding orientation, and Eocene paleogeography. The Oligocene Arctic Ocean-Gulf of Mexico continental divide extended from the southern Absaroka Mountains east along the Owl Creek Mountains, across the southern Powder River Basin, through the northern Black Hills, and eastward across South Dakota. Streams north of the divide flowed northeastward. The Olligocene White River Group contains 50 to 90 percent airfall pyroclastic debris from a northern Great Basin source. Most of the uranium deposits of the region in pre-Oligocene rocks can be related to a uranium source in the volcanic ash of the White River; in many places the pre-Oligocene deposits can be related to specific Oligocene channels. Uranium deposits in sandstones of major Oligocene rivers are an important new type of deposit. The Oligocene channel sandstones also contain small quantities of gold, molybdenum, gas, and oil

New records of Ergasilus (Copepoda: Ergasilidae) in the Laurentian Great Lakes, including a lakewide review of records and host associations

Science.gov (United States)

Hudson, Patrick L.; Bowen, Charles A.; Stedman, Ralph M.

1994-01-01

Ergasilus nerkae was found infecting ninespine stickleback (Pungitius pungitius) in lakes Huron, Michigan, and Superior and threespine stickleback (Gasterosteus aculeatus) and round whitefish (Prosopium cylindraceum) in Lake Huron. Based upon the literature and study of archived material, we propose that E. nerkae is enzootic to the Great Lakes and that ninespine stickleback are a preferred host in Lake Huron. Prevalence of E. nerkae on ninespine stickleback increased from 17% in June to 68% in September, but mean intensity remained light. Prevalence and mean intensity increased with host length. Ergasilus luciopercarum is also reported on lake trout (Salvelinus namaycush) and largemouth bass (Micropterus salmoides) for the first time. Host-parasite records of Ergasilus spp. in North America are reviewed, biology and taxonomy are summarized, and a checklist of Great Lakes host-parasite-locality records is provided. At present, eight species of Ergasilus are known to infect 42 Great Lakes fish species.

Stock discrimination in Great Lakes Walleye using mitochondrial DNA restriction analysis

International Nuclear Information System (INIS)

Billington, N.; Hebert, P.D.N.

1986-01-01

Over the past two years it has become evident that because of its strict maternal inheritance and rapid rate of evolutionary differentiation, mitochondrial (mt) DNA diversity offers exceptional promise in the discrimination of fish stocks. The current project aims to determine the extent of mt DNA variation among stocks of walleye (Stizostedion vitreum) from the Great Lakes. At this point, mt DNA has been isolated from 68 walleye representing the Thames River stock and a reef breeding stock from western Lake Erie, as well as from individuals of S. canadense, a species which hybridizes with S. vitreum. Mitochondrial DNA was extracted from livers of these fish, purified by CsCl density gradient centrifugation and digested using 20 endonucleases. Polymorphisms were detected with 8 of the enzymes. There was a great deal of variation among fish from both spawning populations, so much so that individual fish could be identified by this technique. No single enzyme allowed discrimination of the two stocks, but restriction pattern variation following Dde I digestion permitted separation of 50% of Lake Erie fish from Thames River stock. Comparison of mt DNA restriction patterns of walleye and sauger showed that two species are easily separable, setting the stage for a more detailed study of hybridization between the taxa

Environmental Sensitivity Index (ESI) Atlas: Great Lakes, 1995-1998 (NODC Accession 0013820)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set comprises the Environmental Sensitivity Index (ESI) maps in .PDF format for the following Great Lakes and associated waterways: north, east, and west...

Rating impacts in a multi-stressor world: a quantitative assessment of 50 stressors affecting the Great Lakes.

Science.gov (United States)

Smith, Sigrid D P; Mcintyre, Peter B; Halpern, Benjamin S; Cooke, Roger M; Marino, Adrienne L; Boyer, Gregory L; Buchsbaum, Andy; Burton, G A; Campbell, Linda M; Ciborowski, Jan J H; Doran, Patrick J; Infante, Dana M; Johnson, Lucinda B; Read, Jennifer G; Rose, Joan B; Rutherford, Edward S; Steinman, Alan D; Allan, J David

2015-04-01

Ecosystems often experience multiple environmental stressors simultaneously that can differ widely in their pathways and strengths of impact. Differences in the relative impact of environmental stressors can guide restoration and management prioritization, but few studies have empirically assessed a comprehensive suite of stressors acting on a given ecosystem. To fill this gap in the Laurentian Great Lakes, where considerable restoration investments are currently underway, we used expert elicitation via a detailed online survey to develop ratings of the relative impacts of 50 potential stressors. Highlighting the multiplicity of stressors in this system, experts assessed all 50 stressors as having some impact on ecosystem condition, but ratings differed greatly among stressors. Individual stressors related to invasive and nuisance species (e.g., dreissenid mussels and ballast invasion risk) and climate change were assessed as having the greatest potential impacts. These results mark a shift away from the longstanding emphasis on nonpoint phosphorus and persistent bioaccumulative toxic substances in the Great Lakes. Differences in impact ratings among lakes and ecosystem zones were weak, and experts exhibited surprisingly high levels of agreement on the relative impacts of most stressors. Our results provide a basin-wide, quantitative summary of expert opinion on the present-day influence of all major Great Lakes stressors. The resulting ratings can facilitate prioritizing stressors to achieve management objectives in a given location, as well as providing a baseline for future stressor impact assessments in the Great Lakes and elsewhere.

Weather and eared grebe winter migration near the Great Salt Lake, Utah.

Science.gov (United States)

Williams, Augusta A; Laird, Neil F

2018-03-01

This study provides insight from the use of weather radar observations to understand the characteristics of the eared grebe migration near the Great Salt Lake (GSL) and provides unique information on weather conditions connected to these migration events. Doppler weather radar measurements from the Salt Lake City, Utah WSR-88D radar site (KMTX), along with meteorological surface and rawinsonde data, were used to identify and examine 281 eared grebe migration events across 15 winters from 1997/1998 through 2011/2012. An average of about 19 migration events occurred each winter with considerable interannual variability, as well as large variance in the spatial area and number of birds departing the GSL during each event. The migration events typically occurred during clear sky conditions in the presence of surface high pressure and colder than average surface temperatures. Migration events began 55 min after sunset, on average across the winter seasons, and in one case we demonstrate that an extended, nonstop flight was initiated of the departing eared grebes to northern Mexico. Eared grebes leaving the GSL largely flew above the freezing level with a mean northerly tailwind at flight altitude of 3.1 m s -1 and a westerly, cross-flight wind of 5.0 m s -1 while having an average flight speed at cruising altitude of 16.9 m s -1 , or 61 km h -1 . In addition to determining the variability of meteorological conditions during migration events across the 15 winters, atmospheric conditions during the largest migration event observed are presented and discussed.

2016 RFA for Great Lakes Long-Term Biology Monitoring Program: Phytoplankton Component

Science.gov (United States)

This Request for Applications solicits applications from eligible entities for a cooperative agreement to be awarded for a project to continue the long-term monitoring of phytoplankton in the open waters of the Great Lakes.

Great Lakes prey fish populations: A cross-basin overview of status and trends in 2008

Science.gov (United States)

Gorman, Owen T.; Bunnell, David B.

2009-01-01

Assessments of prey fishes in the Great Lakes have been conducted annually since the 1970s by the Great Lakes Science Center, sometimes assisted by partner agencies. Prey fish assessments differ among lakes in the proportion of a lake covered, seasonal timing, bottom trawl gear used, sampling design, and the manner in which the trawl is towed (across or along bottom contours). Because each assessment is unique in one or more important aspects, a direct comparison of prey fish catches among lakes is problematic. All of the assessments, however, produce indices of abundance or biomass that can be standardized to facilitate comparisons of trends among lakes and to illustrate present status of the populations. We present indices of abundance for important prey fishes in the Great Lakes standardized to the highest value for a time series within each lake: cisco (Coregonus artedi), bloater (C. hoyi), rainbow smelt (Osmerus mordax), and alewife (Alosa pseudoharengus). We also provide indices for round goby (Neogobius melanostomus), an invasive fish presently spreading throughout the basin. Our intent is to provide a short, informal report emphasizing data presentation rather than synthesis; for this reason we intentionally avoid use of tables and cited references.For each lake, standardized relative indices for annual biomass and density estimates of important prey fishes were calculated as the fraction relative to the largest value observed in the times series. To determine whether basin-wide trends were apparent for each species, we first ranked standardized index values within each lake. When comparing ranked index values from three or more lakes, we calculated the Kendall coefficient of concordance (W), which can range from 0 (complete discordance or disagreement among trends) to 1 (complete concordance or agreement among trends). The P-value for W provides the probability of agreement across the lakes. When comparing ranked index values from two lakes, we calculated

75 FR 18451 - Safety and Security Zones; Tall Ships Challenge 2010, Great Lakes; Cleveland, OH; Bay City, MI...

Science.gov (United States)

2010-04-12

...-AA87 Safety and Security Zones; Tall Ships Challenge 2010, Great Lakes; Cleveland, OH; Bay City, MI.... SUMMARY: The Coast Guard proposes to establish temporary safety and security zones around each Tall Ship visiting the Great Lakes during the Tall Ships Challenge 2010 race series. These safety and security zones...

Great Lakes modeling: Are the mathematics outpacing the data and our understanding of the system?

Science.gov (United States)

Mathematical modeling in the Great Lakes has come a long way from the pioneering work done by Manhattan College in the 1970s, when the models operated on coarse computational grids (often lake-wide) and used simple eutrophication formulations. Moving forward 40 years, we are now...

The widespread influence of Great Lakes microseisms across the United States revealed by the 2014 polar vortex

Science.gov (United States)

Anthony, Robert; Ringler, Adam; Wilson, David

2018-01-01

During the winter of 2014, a weak polar vortex brought record cold temperatures to the north‐central (“Midwest”) United States, and the Great Lakes reached the highest extent of ice coverage (92.5%) since 1979. This event shut down the generation of seismic signals caused by wind‐driven wave action within the lakes (termed “lake microseisms”), giving an unprecedented opportunity to isolate and characterize these novel signals through comparison with nonfrozen time periods. Using seismic records at 72 broadband stations, we observe Great Lakes microseism signals at distances >300 km from the lakes. In contrast to conventional oceanic microseisms, there is no clear relationship between the frequency content of the seismic signals (observed from ~0.5–5‐s period) and the dominant swell period or resonance periods of the lakes based on their bathymetric profiles. Thus, the exact generation mechanism is not readily explained by conventional microseism theory and warrants further investigation.

Lake Morphometry for NHD Lakes in Great Lakes Region 4 HUC

Data.gov (United States)

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

Congener Patterns of Persistent Organic Pollutants Establish the Extent of Contaminant Biotransport by Pacific Salmon in the Great Lakes.

Science.gov (United States)

Gerig, Brandon S; Chaloner, Dominic T; Janetski, David J; Rediske, Richard R; O'Keefe, James P; Moerke, Ashley H; Lamberti, Gary A

2016-01-19

In the Great Lakes, introduced Pacific salmon (Oncorhynchus spp.) can transport persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), to new environments during their spawning migrations. To explore the nature and extent of POP biotransport by salmon, we compared 58 PCB and 6 PBDE congeners found in spawning salmon directly to those in resident stream fish. We hypothesized that stream fish exposed to salmon spawners would have congener patterns similar to those of salmon, the presumed contaminant source. Using permutational multivariate analysis of variance (PERMANOVA) and nonmetric multidimensional scaling (NMDS), we found that POP congener patterns of Pacific salmon varied among regions in the Great Lakes basin (i.e., Lake Huron, Lake Michigan, or Lake Superior), tissue type (whole fish or eggs), and contaminant type (PCB or PBDE). For stream-resident fish, POP congener pattern was influenced by the presence of salmon, location (i.e., Great Lakes Basin), and species identity (i.e., brook trout [Salvelinus fontinalis] or mottled sculpin [Cottus bairdii]). Similarity in congener patterns indicated that salmon are a source of POPs to brook trout in stream reaches receiving salmon spawners from Lake Michigan and Lake Huron but not from Lake Superior. Congener patterns of mottled sculpin differed from those of brook trout and salmon, suggesting that brook trout and mottled sculpin either use salmon tissue to differing degrees, acquire POPs from different dietary sources, or bioaccumulate or metabolize POPs differently. Overall, our analyses identified the important role of salmon in contaminant biotransport but also demonstrated that the extent of salmon-mediated POP transfer and uptake in Great Lakes tributaries is location- and species-specific.

Factors Controlling Methane in Arctic Lakes of Southwest Greenland.

Science.gov (United States)

Northington, Robert M; Saros, Jasmine E

2016-01-01

We surveyed 15 lakes during the growing season of 2014 in Arctic lakes of southwest Greenland to determine which factors influence methane concentrations in these systems. Methane averaged 2.5 μmol L-1 in lakes, but varied a great deal across the landscape with lakes on older landscapes farther from the ice sheet margin having some of the highest values of methane reported in lakes in the northern hemisphere (125 μmol L-1). The most important factors influencing methane in Greenland lakes included ionic composition (SO4, Na, Cl) and chlorophyll a in the water column. DOC concentrations were also related to methane, but the short length of the study likely underestimated the influence and timing of DOC on methane concentrations in the region. Atmospheric methane concentrations are increasing globally, with freshwater ecosystems in northern latitudes continuing to serve as potentially large sources in the future. Much less is known about how freshwater lakes in Greenland fit in the global methane budget compared to other, more well-studied areas of the Arctic, hence our work provides essential data for a more complete view of this rapidly changing region.

2010 Great Lakes Human Health Fish Tissue Study Fish Tissue Data Dictionary

Science.gov (United States)

The Office of Science and Technology (OST) is providing the fish tissue results from the 2010 Great Lakes Human Health Fish Tissue Study (GLHHFTS). This document includes the “data dictionary” for Mercury, PFC, PBDE and PCBs.

Stakeholder views of management and decision support tools to integrate climate change into Great Lakes Lake Whitefish management

Science.gov (United States)

Lynch, Abigail J.; Taylor, William W.; McCright, Aaron M.

2016-01-01

Decision support tools can aid decision making by systematically incorporating information, accounting for uncertainties, and facilitating evaluation between alternatives. Without user buy-in, however, decision support tools can fail to influence decision-making processes. We surveyed fishery researchers, managers, and fishers affiliated with the Lake Whitefish Coregonus clupeaformis fishery in the 1836 Treaty Waters of Lakes Huron, Michigan, and Superior to assess opinions of current and future management needs to identify barriers to, and opportunities for, developing a decision support tool based on Lake Whitefish recruitment projections with climate change. Approximately 64% of 39 respondents were satisfied with current management, and nearly 85% agreed that science was well integrated into management programs. Though decision support tools can facilitate science integration into management, respondents suggest that they face significant implementation barriers, including lack of political will to change management and perceived uncertainty in decision support outputs. Recommendations from this survey can inform development of decision support tools for fishery management in the Great Lakes and other regions.

Late Pleistocene Hansel Valley basaltic ash, northern Lake Bonneville, Utah, USA

Science.gov (United States)

Miller, D.M.; Oviatt, Charles G.; Nash, B.P.

2008-01-01

The Hansel Valley ash bed lies within 5 cm of the base of deposits of Lake Bonneville (???28 ka) in the vicinity of Great Salt Lake and provides a useful stratigraphic marker for this area of the lake basin. However, it has not been matched to an eruptive edifice, presumably because such an edifice was eroded by waves of Lake Bonneville. We present data for the chemical composition of the tephra and for possible matching lavas and tephras of the region, as well as grain size data for the tephra in an attempt to identify the location of the eruption. Matches with other tephras are negative, but lavas near the coarsest ash deposits match well with the distinctive high values of TiO2 and P2O5 of the ash. Neither chemistry nor grain size data points uniquely to a source area, but an area near the northwest shore of Great Salt Lake and within Curlew Valley is most likely. The Hansel Valley ash is an example of an ash that has no direct numerical date from proximal deposits, despite considerable study, yet nonetheless is useful for stratigraphic studies by virtue of its known stratigraphic position and approximate age. Basaltic tephras commonly are not as widespread as their rhyolitic counterparts, and in some cases apparently are produced by eruptive sources that are short lived and whose edifices are not persistent. ?? 2007 Elsevier Ltd and INQUA.

The traditional irrigation technique of Lake Garda lemon--houses (Northern Italy)

Science.gov (United States)

Barontini, Stefano; Vitale, Nicola; Fausti, Federico; Bettoni, Barbara; Bonati, Sara; Peli, Marco; Pietta, Antonella; Tononi, Marco; Ranzi, Roberto

2016-04-01

Between 16th and 19th centuries the North-Western side of Lake Garda was seat of an important district which, at the time of its maximum splendour between 18th and 19th centuries, produced and exported lemons and citrus even toward the Northern Europe and the Russia. The limonaie del Garda (Lake-Garda lemon-houses), the local name of the citrus orchards, were settled on terraces built on steep slopes, with landfill taken from the Eastern side of the lake, and closed by greenhouses during late autumn and winter in order to protect the cultivations. The terraces were built nearby streams, they were South-Eastern exposed and protected by walls from the cold winds. Thanks in fact to the Lake Garda microclimate, lemon trees were not cultivated in pots, as in the typical orangeries of mid-latitudes Europe, but directly in the soil. Here the citrus cultivation technique reached a remarkably high degree of standardisation, with local cultivar as the Madernino or lemon from Maderno, and it involved, as in modern industrial districts, all the surrounding land in order to satisfy the needing of required materials to build the terraces, the walls, the greenhouses and the wooden frames to hold the branches laden with fruits. Due to the great water requirement of lemon trees during summer, which is estimated to range from 150 to 300 ℓ every ten days, the water management played a key role in the cultivation technique. The traditional irrigation technique was standardized as well. During our surveys, we observed that most of the lemon-houses still conserve little stone flumes along the walls upslope to the terraces, with spillways every adult tree, i.e. about every 4 m. The flumes were filled with water taken from an upstream reservoir, built nearby a stream. The spillways were activated with a backwater obtained by means of a sand bag placed within the flume, just downstream to the spillway itself. In order to avoid any excavation, spilled water was driven to the base of each

Diet and habitat use by age-0 deepwater sculpins in northern Lake Huron, Michigan and the Detroit River

Science.gov (United States)

Roseman, Edward F.

2014-01-01

Deepwater sculpins (Myoxocephalus thompsonii) are an important link in deepwater benthic foodwebs of the Great Lakes. Little information exists about deepwater sculpin spawning habits and early life history ecology due to difficulty in sampling deep offshore habitats. Larval and age-0 deepwater sculpins collected in northern Lake Huron and the Detroit River during 2007 were used to improve our understanding of their habitat use, diet, age, and growth. Peak larval density reached 8.4/1000 m3 in the Detroit River during April and was higher than that in Lake Huron. Offshore bottom trawls at DeTour and Hammond Bay first collected benthic age-0 deepwater sculpins in early September when fish were ≥ 25 mm TL. Otolith analysis revealed that hatch dates for pelagic larvae occurred during late March and larvae remained pelagic for 40 to 60 days. Diet of pelagic larvae (10–21 mm TL) was dominated by calanoid copepods at all sample locations. Diets of benthic age-0 fish varied by location and depth: Mysis and chironomids were prevalent in fish from Hammond Bay and the 91 m site at DeTour, but only chironomids were found in fish from the 37 m DeTour site. This work showed that nearshore epilimnetic sites were important for pelagic larvae and an ontogenetic shift from pelagic planktivore to benthivore occurred at about 25 mm TL in late summer. Age analysis showed that larvae remained pelagic long enough to be transported through the St. Clair–Detroit River system, Lake Erie, and the Niagara River, potentially contributing to populations in Lake Ontario.

76 FR 37646 - Safety Zone; Northern California Annual Fireworks Events, Fourth of July Fireworks, Lake Tahoe, CA

Science.gov (United States)

2011-06-28

... Zone; Northern California Annual Fireworks Events, Fourth of July Fireworks, Lake Tahoe, CA AGENCY... annual safety zone for the Fourth of July Fireworks, Lake Tahoe, California, located off Incline Village...,000 foot safety zone for the annual Fourth of July Fireworks Display in 33 CFR 165.1191 on July 4...

Shifting balance of thermokarst lake ice regimes across the Arctic Coastal Plain of northern Alaska

Science.gov (United States)

Arp, Christopher D.; Jones, Benjamin M.; Lu, Zong; Whitman, Matthew S.

2012-01-01

The balance of thermokarst lakes with bedfast- and floating-ice regimes across Arctic lowlands regulates heat storage, permafrost thaw, winter-water supply, and over-wintering aquatic habitat. Using a time-series of late-winter synthetic aperture radar (SAR) imagery to distinguish lake ice regimes in two regions of the Arctic Coastal Plain of northern Alaska from 2003–2011, we found that 18% of the lakes had intermittent ice regimes, varying between bedfast-ice and floating-ice conditions. Comparing this dataset with a radar-based lake classification from 1980 showed that 16% of the bedfast-ice lakes had shifted to floating-ice regimes. A simulated lake ice thinning trend of 1.5 cm/yr since 1978 is believed to be the primary factor driving this form of lake change. The most profound impacts of this regime shift in Arctic lakes may be an increase in the landscape-scale thermal offset created by additional lake heat storage and its role in talik development in otherwise continuous permafrost as well as increases in over-winter aquatic habitat and winter-water supply.

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

Science.gov (United States)

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

2013-04-01

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

Long-term Agroecosystem Research in the Northern Great Plains.

Science.gov (United States)

Schmer, M.; Sanderson, M.; Liebig, M. A.; Wienhold, B.; Awada, T.; Papiernik, S.; Osborne, S.; Kemp, W.; Okalebo, J. A.; Riedall, W.

2015-12-01

The Northern Great Plains is the bread basket of the United States, accounting for a substantial portion of U.S. agricultural production. This region faces critical challenges regarding balancing food needs, resource conservation (e.g Ogallala aquifer), environmental concerns, and rural economy development. Developing transformative, multifunctional systems will require equally imaginative and efficient tools to help farmers manage complex agroecosystems in a rapidly changing climate. The Northern Plains long-term agroecosystem research (LTAR) site at Mandan, ND and the Platte River High Plains LTAR (ARS/University of Nebraska-Lincoln) at Lincoln, NE in collaboration with USDA-ARS research units in Brookings, SD and Fargo, ND are collaborating to address the grand challenge of providing and sustaining multiple service provisions from Northern Great Plains agroecosystems. We propose to attain these goals through sustainable intensification based on the adoption of conservation agriculture principles including reduced soil disturbance, livestock integration, and greater complexity and diversity in the cropping system. Here, we summarize new concepts these locations have pioneered in dynamic cropping systems, resource use efficiency, and agricultural management technologies. As part of the LTAR network, we will conduct long-term cross-site research to design and assess new agricultural practices and systems aimed at improving our understanding of decision making processes and outcomes across an array of agricultural systems.

Ecotoxicology of organochlorine chemicals in birds of the Great Lakes

Science.gov (United States)

Tillitt, Donald E.; Giesy, John P.

2013-01-01

Silent Spring was fulfilled in the United States with passage of environmental legislation such as the Clean Water Act, the Federal Insecticide, Fungicide, and Rodenticide Act, and the Toxic Substance Control Act in the 1970s. Carson's writings, television interviews, and testimony before Congress alerted a nation and the world to the unintended effects of persistent, bioaccumulative chemicals on populations of fish, wildlife, and possibly humans. Her writings in the popular press brought attention to scientific findings that declines in populations of a variety of birds were directly linked to the widespread use of dichlorodiphenyltrichloroethane (DDT) in agriculture, public health, and horticulture. By the 1970s, DDT and other persistent organic pollutants (POPs) were being banned or phased out, and the intent of these regulatory acts became apparent in a number of locations across the United States, including the Great Lakes. Concentrations of DDT and its major product of transformation, dichlorodiphenylchloroethane (DDE), were decreasing in top predators, such as bald eagles (Haliaeetus leucocephalus), osprey (Pandion haliaetus), colonial waterbirds, and other fish-eating wildlife. Eggshell thinning and the associated mortality of bird embryos caused by DDE had decreased in the Great Lakes and elsewhere by the early 1980s.

Population ecology of the sea lamprey (Petromyzon marinus) as an invasive species in the Laurentian Great Lakes and an imperiled species in Europe

Science.gov (United States)

Hansen, Michael J.; Madenjian, Charles P.; Slade, Jeffrey W.; Steeves, Todd B.; Almeida, Pedro R.; Quintella, Bernardo R.

2016-01-01

The sea lamprey Petromyzon marinus (Linnaeus) is both an invasive non-native species in the Laurentian Great Lakes of North America and an imperiled species in much of its native range in North America and Europe. To compare and contrast how understanding of population ecology is useful for control programs in the Great Lakes and restoration programs in Europe, we review current understanding of the population ecology of the sea lamprey in its native and introduced range. Some attributes of sea lamprey population ecology are particularly useful for both control programs in the Great Lakes and restoration programs in the native range. First, traps within fish ladders are beneficial for removing sea lampreys in Great Lakes streams and passing sea lampreys in the native range. Second, attractants and repellants are suitable for luring sea lampreys into traps for control in the Great Lakes and guiding sea lamprey passage for conservation in the native range. Third, assessment methods used for targeting sea lamprey control in the Great Lakes are useful for targeting habitat protection in the native range. Last, assessment methods used to quantify numbers of all life stages of sea lampreys would be appropriate for measuring success of control in the Great Lakes and success of conservation in the native range.

Geochemistry of great Salt Lake, Utah II: Pleistocene-Holocene evolution

Science.gov (United States)

Spencer, R.J.; Eugster, H.P.; Jones, B.F.

1985-01-01

Sedimentologic and biostratigraphic evidence is used to develop a geochemical model for Great Salt Lake, Utah, extending back some 30,000 yrs. B.P. Hydrologie conditions as defined by the water budget equation are characterized by a lake initially at a low, saline stage, rising by about 17,000 yrs. B.P. to fresh water basin-full conditions (Bonneville level) and then, after about 15,000 yrs. B.P., dropping rapidly to a saline stage again, as exemplified by the present situation. Inflow composition has changed through time in response to the hydrologie history. During fresh-water periods high discharge inflow is dominated by calcium bicarbonate-type river waters; during saline stages, low discharge, NaCl-rich hydrothermal springs are significant solute sources. This evolution in lake composition to NaCl domination is illustrated by the massive mirabilite deposition, free of halite, following the rapid drawdown until about 8,000 years ago, while historic droughts have yielded principally halite. Hydrologic history can be combined with inferred inflow composition to derive concentration curves with time for each major solute in the lake. Calcium concentrations before the drawdown were controlled by calcite solubility, and afterwards by aragonite. Significant amounts of solutes are removed from the lake by diffusion into the sediments. Na+, Cl- and SO42- are also involved in salt precipitation. By including pore fluid data, a surprisingly good fit has been obtained between solute input over the time period considered and the amounts actually found in lake brines, pore fluids, salt beds and sediments. Excess amounts are present for calcium, carbonate and silica, indicating detrital input. ?? 1985.

40 CFR Appendix D to Part 132 - Great Lakes Water Quality Initiative Methodology for the Development of Wildlife Criteria

Science.gov (United States)

2010-07-01

... Methodology for the Development of Wildlife Criteria D Appendix D to Part 132 Protection of Environment... Development of Wildlife Criteria Great Lakes States and Tribes shall adopt provisions consistent with (as protective as) this appendix. I. Introduction A. A Great Lakes Water Quality Wildlife Criterion (GLWC) is the...

Evolution and origin of sympatric shallow-water morphotypes of Lake Trout, Salvelinus namaycush, in Canada's Great Bear Lake.

Science.gov (United States)

Harris, L N; Chavarie, L; Bajno, R; Howland, K L; Wiley, S H; Tonn, W M; Taylor, E B

2015-01-01

Range expansion in north-temperate fishes subsequent to the retreat of the Wisconsinan glaciers has resulted in the rapid colonization of previously unexploited, heterogeneous habitats and, in many situations, secondary contact among conspecific lineages that were once previously isolated. Such ecological opportunity coupled with reduced competition likely promoted morphological and genetic differentiation within and among post-glacial fish populations. Discrete morphological forms existing in sympatry, for example, have now been described in many species, yet few studies have directly assessed the association between morphological and genetic variation. Morphotypes of Lake Trout, Salvelinus namaycush, are found in several large-lake systems including Great Bear Lake (GBL), Northwest Territories, Canada, where several shallow-water forms are known. Here, we assess microsatellite and mitochondrial DNA variation among four morphotypes of Lake Trout from the five distinct arms of GBL, and also from locations outside of this system to evaluate several hypotheses concerning the evolution of morphological variation in this species. Our data indicate that morphotypes of Lake Trout from GBL are genetically differentiated from one another, yet the morphotypes are still genetically more similar to one another compared with populations from outside of this system. Furthermore, our data suggest that Lake Trout colonized GBL following dispersal from a single glacial refugium (the Mississippian) and support an intra-lake model of divergence. Overall, our study provides insights into the origins of morphological and genetic variation in post-glacial populations of fishes and provides benchmarks important for monitoring Lake Trout biodiversity in a region thought to be disproportionately susceptible to impacts from climate change.

Great Lake beach-goer behavior during a retrospectively detected bloom of cyanobacteria

Science.gov (United States)

Cyanobacteria blooms pose a potential health risk to beachgoers. We conducted a prospective study of weekend beachgoers at a public Great Lake site during July – September 2003. We recorded each person’s health status and activity during their beach visit. We measured...

Mapping ecosystem service indicators in a Great Lakes estuarine Area of Concern

Science.gov (United States)

Estuaries provide multiple ecosystem services from which humans benefit. Currently, thirty-six Great Lakes estuaries in the United States and Canada are designated as Areas of Concern (AOCs) due to a legacy of chemical contamination, degraded habitat, and non-point-source polluti...

Flood-inundation maps for Lake Champlain in Vermont and in northern Clinton County, New York

Science.gov (United States)

Flynn, Robert H.; Hayes, Laura

2016-06-30

Digital flood-inundation maps for an approximately100-mile length of Lake Champlain in Addison, Chittenden, Franklin, and Grand Isle Counties in Vermont and northern Clinton County in New York were created by the U.S. Geological Survey (USGS) in cooperation with the International Joint Commission (IJC). The flood-inundationmaps, which can be accessed through the International Joint Commission (IJC) Web site at http://www.ijc.org/en_/, depict estimates of the areal extent flooding correspondingto selected water levels (stages) at the USGS lake gage on the Richelieu River (Lake Champlain) at Rouses Point, N.Y. (station number 04295000). In this study, wind and seiche effects (standing oscillating wave with a long wavelength) were not taken into account and the flood-inundation mapsreflect 11 stages (elevations) for Lake Champlain that are static for the study length of the lake. Near-real-time stages at this lake gage, and others on Lake Champlain, may be obtained on the Internet from the USGS National Water Information System at http://waterdata.usgs.gov/ or the National Weather Service Advanced Hydrologic Prediction Service at http:/water.weather.gov/ahps/, which also forecasts flood hydrographs at the Richelieu River (Lake Champlain) at Rouses Point.Static flood boundary extents were determined for LakeChamplain in Addison, Chittenden, Franklin, and Grand Isle Counties in Vermont and northern Clinton County in New York using recently acquired (2013–2014) lidar (light detection and ranging) and may be referenced to any of the five USGS lake gages on Lake Champlain. Of these five lakgages, USGS lake gage 04295000, Richelieu River (Lake Champlain) at Rouses Point, N.Y., is the only USGS lake gage that is also a National Weather Service prediction location. Flood boundary extents for the Lake Champlain static flood-inundation map corresponding to the May 201 flood(103.2 feet [ft], National Geodetic Vertical Datum [NGVD] 29) were evaluated by comparing these boundary

New insight into the spawning behavior of lake trout, Salvelinus namaycush, from a recovering population in the Laurentian Great Lakes

Science.gov (United States)

Binder, Thomas R.; Thompson, Henry T.; Muir, Andrew M.; Riley, Stephen C.; Marsden, J. Ellen; Bronte, Charles R.; Krueger, Charles C.

2015-01-01

Spawning behavior of lake trout, Salvelinus namaycush, is poorly understood, relative to stream-dwelling salmonines. Underwater video records of spawning in a recovering population from the Drummond Island Refuge (Lake Huron) represent the first reported direct observations of lake trout spawning in the Laurentian Great Lakes. These observations provide new insight into lake trout spawning behavior and expand the current conceptual model. Lake trout spawning consisted of at least four distinct behaviors: hovering, traveling, sinking, and gamete release. Hovering is a new courtship behavior that has not been previously described. The apparent concentration of hovering near the margin of the spawning grounds suggests that courtship and mate selection might be isolated from the spawning act (i.e., traveling, sinking, and gamete release). Moreover, we interpret jockeying for position displayed by males during traveling as a unique form of male-male competition that likely evolved in concert with the switch from redd-building to itinerant spawning in lake trout. Unlike previous models, which suggested that intra-sexual competition and mate selection do not occur in lake trout, our model includes both and is therefore consistent with evolutionary theory, given that the sex ratio on spawning grounds is skewed heavily towards males. The model presented in this paper is intended as a working hypothesis, and further revision may become necessary as we gain a more complete understanding of lake trout spawning behavior.

Contaminants of emerging concern presence and adverse effects in fish: A case study in the Laurentian Great Lakes

Science.gov (United States)

Jorgenson, Zachary G.; Thomas, Linnea M.; Elliott, Sarah M.; Cavallin, Jenna E.; Randolph, Eric C.; Choy, Steven J.; Alvarez, David; Banda, Jo A.; Gefell, Daniel J.; Lee, Kathy E.; Furlong, Edward T.; Schoenfuss, Heiko L.

2018-01-01

The Laurentian Great Lakes are a valuable natural resource that is affected by contaminants of emerging concern (CECs), including sex steroid hormones, personal care products, pharmaceuticals, industrial chemicals, and new generation pesticides. However, little is known about the fate and biological effects of CECs in tributaries to the Great Lakes. In the current study, 16 sites on three rivers in the Great Lakes basin (Fox, Cuyahoga, and Raquette Rivers) were assessed for CEC presence using polar organic chemical integrative samplers (POCIS) and grab water samplers. Biological activity was assessed through a combination of in vitro bioassays (focused on estrogenic activity) and in vivo assays with larval fathead minnows. In addition, resident sunfish, largemouth bass, and white suckers were assessed for changes in

Bi-national Great Lakes-St. Lawrence Basin climate change and hydrologic scenarios report

Energy Technology Data Exchange (ETDEWEB)

Lavender, B.; Smith, J.V.; Koshida, G.; Mortsch, L.D. [eds.

1998-09-01

Climate experts in government, industry and academic institutions have put together a national assessment of how climate change will affect Canadians and their social, biological and economic environment over the next century. This volume documents the impacts and implications of climate change on the Great Lakes-St. Lawrence Basin, and provides an analysis and assessment of various climate and hydrologic scenarios used for the Great Lakes - St. Lawrence Basin Project. As part of the analysis and assessment, results from the Canadian Climate Centre second-generation General Circulation Model and four transposition scenarios for both climate and hydrological resources are reviewed. The objective is to provide an indication of sensitivities and vulnerabilities of the region to climate, with a view to improve adaptation to potential climate changes. 25 tabs., 26 figs. figs.

Recent Trends in Soil Science and Agronomy Research in the Northern Great Plains of North America

Science.gov (United States)

The book “Recent Trends in Soil Science and Agronomy Research in the Northern Great Plains of North America” summarizes published research in soil science and agronomy from various field experiments conducted in the soil-climatic/agro-ecological regions of the Northern Great Plains of North America....

A sensor-based energy balance method for the distributed estimation of evaporation over the North American Great Lakes

Science.gov (United States)

Fries, K. J.; Kerkez, B.; Gronewold, A.; Lenters, J. D.

2014-12-01

We introduce a novel energy balance method to estimate evaporation across large lakes using real-time data from moored buoys and mobile, satellite-tracked drifters. Our work is motivated by the need to improve our understanding of the water balance of the Laurentian Great Lakes basin, a complex hydrologic system that comprises 90% of the United States' and 20% of the world's fresh surface water. Recently, the lakes experienced record-setting water level drops despite above-average precipitation, and given that lake surface area comprises nearly one third of the entire basin, evaporation is suspected to be the primary driver behind the decrease in water levels. There has historically been a need to measure evaporation over the Great Lakes, and recent hydrological phenomena (including not only record low levels, but also extreme changes in ice cover and surface water temperatures) underscore the urgency of addressing that need. Our method tracks the energy fluxes of the lake system - namely net radiation, heat storage and advection, and Bowen ratio. By measuring each of these energy budget terms and combining the results with mass-transfer based estimates, we can calculate real-time evaporation rates on sub-hourly timescales. To mitigate the cost prohibitive nature of large-scale, distributed energy flux measurements, we present a novel approach in which we leverage existing investments in seasonal buoys (which, while providing intensive, high quality data, are costly and sparsely distributed across the surface of the Great Lakes) and then integrate data from less costly satellite-tracked drifter data. The result is an unprecedented, hierarchical sensor and modeling architecture that can be used to derive estimates of evaporation in real-time through cloud-based computing. We discuss recent deployments of sensor-equipped buoys and drifters, which are beginning to provide us with some of the first in situ measurements of overlake evaporation from Earth's largest lake

75 FR 51191 - Great Lakes Pilotage Rates-2011 Annual Review and Adjustment

Science.gov (United States)

2010-08-19

... the Great Lakes to generate sufficient revenue to cover allowable expenses, target pilot compensation, and return on investment. The proposed update reflects a projected August 1, 2011, increase in... adjusting the pilotage rates for the 2011 shipping season to generate sufficient revenue to cover allowable...

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

Science.gov (United States)

Currey, Donald R.

1989-01-01

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

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.

Across Hydrological Interfaces from Coastal Watersheds to the Open Lake: Finding Landscape Signals in the Great Lakes Coastal Zone

Science.gov (United States)

Over the past decade, our group has been working to bring coastal ecosystems into integrated basin-lakewide monitoring and assessment strategies for the Great Lakes. We have conducted a wide range of research on coastal tributaries, coastal wetlands, semi-enclosed embayments an...

Can migration mitigate the effects of ecosystem change? Patterns of dispersal, energy acquisition and allocation in Great Lakes lake whitefish (Coregonus clupeaformis)

Science.gov (United States)

Rennie, Michael D.; Ebener, Mark P.; Wagner, Tyler

2012-01-01

Migration can be a behavioural response to poor or declining home range habitat quality and can occur when the costs of migration are overcome by the benefi ts of encountering higher-quality resources elsewhere. Despite dramatic ecosystem-level changes in the benthic food web of the Laurentian Great Lakes since the colonization of dreissenid mussels, coincident changes in condition and growth rates among benthivorous lake whitefi sh populations have been variable. We hypothesized that this variation could be in part mitigated by differences in migratory habits among populations, where increased migration distance can result in an increased probability of encountering high-quality habitat (relative to the home range). Results from four Great Lakes populations support this hypothesis; relative growth rates increased regularly with migration distance. The population with the largest average migration distance also had the least reduction in size-at-age during a period of signifi cant ecosystem change and among the highest estimated consumption and activity rates. In comparison, the population with the greatest declines in size-at-age was among the least mobile, demonstrating only moderate rates of consumption and activity. The least mobile population of lake whitefi sh was supported by a remnant Diporeia population and has experienced only moderate temporal growth declines. Our study provides evidence for the potential role of migration in mitigating the effects of ecosystem change on lake whitefi sh populations.

Investigating Human-Induced Changes of Elemental Cycles in the Great Lakes

Science.gov (United States)

Baskaran, Mark; Bratton, John

2013-07-01

Food webs and associated elemental cycles in the Laurentian Great Lakes have been considerably altered over the past 30 years due to factors such as phosphorus abatement, introduction of zebra and quagga mussels, and climate change. These perturbations provide a unique opportunity to document how this natural system has responded and possibly to predict future changes in biogeochemical cycling.

Beneficial use of dredged materials in Great Lakes commercial ports for transportation projects.

Science.gov (United States)

2014-05-01

This report describes an effort to facilitate beneficial use of dredged materials (DM) from Great Lakes ports and harbors as an alternative construction : material in transportation-related earthwork applications. The overall objective is to link tog...

Development of a Bi-National Great Lakes Coastal Wetland and Land Use Map Using Three-Season PALSAR and Landsat Imagery

Directory of Open Access Journals (Sweden)

Laura Bourgeau-Chavez

2015-07-01

Full Text Available Methods using extensive field data and three-season Landsat TM and PALSAR imagery were developed to map wetland type and identify potential wetland stressors (i.e., adjacent land use for the United States and Canadian Laurentian coastal Great Lakes. The mapped area included the coastline to 10 km inland to capture the region hydrologically connected to the Great Lakes. Maps were developed in cooperation with the overarching Great Lakes Consortium plan to provide a comprehensive regional baseline map suitable for coastal wetland assessment and management by agencies at the local, tribal, state, and federal levels. The goal was to provide not only land use and land cover (LULC baseline data at moderate spatial resolution (20–30 m, but a repeatable methodology to monitor change into the future. The prime focus was on mapping wetland ecosystem types, such as emergent wetland and forested wetland, as well as to delineate wetland monocultures (Typha, Phragmites, Schoenoplectus and differentiate peatlands (fens and bogs from other wetland types. The overall accuracy for the coastal Great Lakes map of all five lake basins was 94%, with a range of 86% to 96% by individual lake basin (Huron, Ontario, Michigan, Erie and Superior.

Unraveling the complex local-scale flows influencing ozone patterns in the southern Great Lakes of North America

Directory of Open Access Journals (Sweden)

I. Levy

2010-11-01

Full Text Available This study examines the complexity of various processes influencing summertime ozone levels in the southern Great Lakes region of North America. Results from the Border Air Quality and Meteorology (BAQS-Met field campaign in the summer of 2007 are examined with respect to land-lake differences and local meteorology using a large array of ground-based measurements, aircraft data, and simulation results from a high resolution (2.5 km regional air-quality model, AURAMS.

Analyses of average ozone mixing ratio from the entire BAQS-Met intensive campaign period support previous findings that ozone levels are higher over the southern Great Lakes than over the adjacent land. However, there is great heterogeneity in the spatial distribution of surface ozone over the lakes, particularly over Lake Erie during the day, with higher levels located over the southwestern end of the lake. Model results suggest that some of these increased ozone levels are due to local emission sources in large nearby urban centers. While an ozone reservoir layer is predicted by the AURAMS model over Lake Erie at night, the land-lake differences in ozone mixing ratios are most pronounced during the night in a shallow inversion layer of about 200 m above the surface. After sunrise, these differences have a limited effect on the total mass of ozone over the lakes and land during the day, though they do cause elevated ozone levels in the lake-breeze air in some locations.

The model also predicts a mean vertical circulation during the day with an updraft over Detroit-Windsor and downdraft over Lake St. Clair, which transports ozone up to 1500 m above ground and results in high ozone over the lake.

Oscillations in ground-level ozone mixing ratios were observed on several nights and at several ground monitoring sites, with amplitudes of up to 40 ppbv and time periods of 15–40 min. Several possible mechanisms for these oscillations are discussed, but a

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.

Added value from 576 years of tree-ring records in the prediction of the Great Salt Lake level

Science.gov (United States)

Robert R. Gillies; Oi-Yu Chung; S.-Y. Simon Wang; R. Justin DeRose; Yan Sun

2015-01-01

Predicting lake level fluctuations of the Great Salt Lake (GSL) in Utah - the largest terminal salt-water lake in the Western Hemisphere - is critical from many perspectives. The GSL integrates both climate and hydrological variations within the region and is particularly sensitive to low-frequency climate cycles. Since most hydroclimate variable records cover...

Attenuation of landscape signals through the coastal zone: A basin-wide analysis for the US Great Lakes shoreline, circa 2002-2010

Science.gov (United States)

We compare statistical models developed to describe a) the relationship between watershed properties and Great Lakes coastal wetlands with b) the relationship developed between watershed properties and the Great Lakes nearshore. Using landscape metrics from the GLEI project (Dan...

Modern thermokarst lake dynamics in the continuous permafrost zone, northern Seward Peninsula, Alaska

Science.gov (United States)

Jones, Benjamin M.; Grosse, G.; Arp, C.D.; Jones, M.C.; Walter, Anthony K.M.; Romanovsky, V.E.

2011-01-01

Quantifying changes in thermokarst lake extent is of importance for understanding the permafrost-related carbon budget, including the potential release of carbon via lake expansion or sequestration as peat in drained lake basins. We used high spatial resolution remotely sensed imagery from 1950/51, 1978, and 2006/07 to quantify changes in thermokarst lakes for a 700 km2 area on the northern Seward Peninsula, Alaska. The number of water bodies larger than 0.1 ha increased over the entire observation period (666 to 737 or +10.7%); however, total surface area decreased (5,066 ha to 4,312 ha or -14.9%). This pattern can largely be explained by the formation of remnant ponds following partial drainage of larger water bodies. Thus, analysis of large lakes (>40 ha) shows a decrease of 24% and 26% in number and area, respectively, differing from lake changes reported from other continuous permafrost regions. Thermokarst lake expansion rates did not change substantially between 1950/51 and 1978 (0.35 m/yr) and 1978 and 2006/07 (0.39 m/yr). However, most lakes that drained did expand as a result of surface permafrost degradation before lateral drainage. Drainage rates over the observation period were stable (2.2 to 2.3 per year). Thus, analysis of decadal-scale, high spatial resolution imagery has shown that lake drainage in this region is triggered by lateral breaching and not subterranean infiltration. Future research should be directed toward better understanding thermokarst lake dynamics at high spatial and temporal resolution as these systems have implications for landscape-scale hydrology and carbon budgets in thermokarst lake-rich regions in the circum-Arctic.

Notes on dredging in the Great Bitter Lake of the Suez Canal

NARCIS (Netherlands)

Beets, C.

1953-01-01

INTRODUCTION In the summer of 1950, the present writer spent a three weeks' holiday dredging in the Great Bitter Lake. Plans to collect specimens in that area for the Rijksmuseum van Natuurlijke Historie at Leiden had, unfortunately, to be drawn up somewhat hurriedly, but at least the most essential

Year-round presence of neonicotinoid insecticides in tributaries to the Great Lakes, USA

Science.gov (United States)

To better understand the transport of neonicotinoid insecticides to a sensitive freshwater ecosystem, monthly samples (October 2015-September 2016) were collected from 10 major tributaries to the Great Lakes, USA. For the monthly tributary samples, neonicotinoids were detected in...

Physical behavior of PCBs in the Great Lakes

International Nuclear Information System (INIS)

McKay, D.; Eisenreich, S.J.; Patterson, S.; Simmons, M.S.

1983-01-01

This book presents a review of all aspects of the physical behavior of one contaminant (PCBs) in one aquatic environment (Great Lakes). This book not only treats this topic extensively, but also serves as a model for treatment of other contaminants in other aquatic environments. This book focuses on the physical rather than biological aspects of PCBs. This focus does not imply a lack of concern for the biosphere or for the effects or toxicology of PCBs; instead, it represents an attempt to tackle a smaller problem of manageable proportions. The environmental fate of PCBs is largely controlled by physical processes, with biodegradation of lower chlorine congeners as the outstanding exception

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.

Holocene evolution of lakes in the forest-tundra biome of northern Manitoba, Canada

Science.gov (United States)

Hobbs, William O.; Edlund, Mark B.; Umbanhowar, Charles E.; Camill, Philip; Lynch, Jason A.; Geiss, Christoph; Stefanova, Vania

2017-03-01

The late-Quaternary paleoenvironmental history of the western Hudson Bay region of Subarctic Canada is poorly constrained. Here, we present a regional overview of the post-glacial history of eight lakes which span the forest-tundra biome in northern Manitoba. We show that during the penultimate drainage phase of Lake Agassiz the lake water had an estimated pH of ∼6.0, with abundant quillwort (Isöetes spp.) along the lakeshore and littoral zone and some floating green algae (Botryococcus spp. and Pediastrum sp.). Based on multiple sediment proxies, modern lake ontogeny in the region commenced at ∼7500 cal yrs BP. Pioneering diatom communities were shaped by the turbid, higher alkalinity lake waters which were influenced by base cation weathering of the surrounding till following Lake Agassiz drainage. By ∼7000 cal yrs BP, soil development and Picea spp. establish and the lakes began a slow trajectory of acidification over the remaining Holocene epoch. The natural acidification of the lakes in this region is slow, on the order of several millennia for one pH unit. Each of the study lakes exhibit relatively stable aquatic communities during the Holocene Thermal Maximum, suggesting this period is a poor analogue for modern climatic changes. During the Neoglacial, the beginning of the post-Little Ice Age period represents the most significant climatic event to impact the lakes of N. Manitoba. In the context of regional lake histories, the rate of diatom floristic change in the last 200-300 years is unprecedented, with the exception of post-glacial lake ontogeny in some of the lakes. For nearly the entire history of the lakes in this region, there is a strong linkage between landscape development and the aquatic ecosystems; however this relationship appears to become decoupled or less strong in the post-LIA period. Significant 20th century changes in the aquatic ecosystem cannot be explained wholly by changes in the terrestrial ecosystem, suggesting that future

Biological effects-based tools for monitoring impacted surface waters in the Great Lakes: a multiagency program in support of the Great Lakes Restoration Initiative

Science.gov (United States)

Ekman, Drew R.; Ankley, Gerald T.; Blazer, Vicki; Collette, Timothy W.; Garcia-Reyero, Natàlia; Iwanowicz, Luke R.; Jorgensen, Zachary G.; Lee, Kathy E.; Mazik, Pat M.; Miller, David H.; Perkins, Edward J.; Smith, Edwin T.; Tietge, Joseph E.; Villeneuve, Daniel L.

2013-01-01

There is increasing demand for the implementation of effects-based monitoring and surveillance (EBMS) approaches in the Great Lakes Basin to complement traditional chemical monitoring. Herein, we describe an ongoing multiagency effort to develop and implement EBMS tools, particularly with regard to monitoring potentially toxic chemicals and assessing Areas of Concern (AOCs), as envisioned by the Great Lakes Restoration Initiative (GLRI). Our strategy includes use of both targeted and open-ended/discovery techniques, as appropriate to the amount of information available, to guide a priori end point and/or assay selection. Specifically, a combination of in vivo and in vitro tools is employed by using both wild and caged fish (in vivo), and a variety of receptor- and cell-based assays (in vitro). We employ a work flow that progressively emphasizes in vitro tools for long-term or high-intensity monitoring because of their greater practicality (e.g., lower cost, labor) and relying on in vivo assays for initial surveillance and verification. Our strategy takes advantage of the strengths of a diversity of tools, balancing the depth, breadth, and specificity of information they provide against their costs, transferability, and practicality. Finally, a series of illustrative scenarios is examined that align EBMS options with management goals to illustrate the adaptability and scaling of EBMS approaches and how they can be used in management decisions.

Seasonal weather-related decision making for cattle production in the Northern Great Plains

Science.gov (United States)

High inter-annual variability of seasonal weather patterns can greatly affect forage and therefore livestock production in the Northern Great Plains. This variability can make it difficult for ranchers to set yearly stocking rates, particularly in advance of the grazing season. To better understand ...

REMOTE DETENTION OF INVASIVE AND OPPORTUNISTIC PLANT SPECIES IN GREAT LAKES COASTAL WETLANDS

Science.gov (United States)

Invasive and opportunistic plant species have been associated with wetland disturbance. Increases in the abundance of plant species such as common reed (Phragmites australis) in coastal Great Lakes wetlands are hypothesized to occur with shifts toward drier hydrologic regimes, fr...

A field guide to valuable underwater aquatic plants of the Great Lakes

Science.gov (United States)

Schloesser, Donald W.

1986-01-01

Underwater plants are a valuable part of the Great Lakes ecosystem, providing food and shelter for aquatic animals. Aquatic plants also help stabilize sediments, thereby reducing shoreline erosion. Annual fall die-offs of underwater plants provide food and shelter for overwintering small aquatic animals such as insects, snails, and freshwater shrimp.

Palynology, sedimentology and environmental significance of Holocene swamps at northern Kaitoke, Great Barrier Island, New Zealand

International Nuclear Information System (INIS)

Horrocks, M.; Ogden, J.; Nichol, S.L.; Alloway, B.V.; Sutton, D.G.

2000-01-01

Pollen and sediment analyses of two cores from coastal freshwater swamps at northern Kaitoke (Kaitoke Swamp and Police Station Swamp), Great Barrier Island, show that c. 7300 calibrated yr BP Kaitoke Swamp was an estuary with tidal flats. Avicennia, now absent from the swamp area, was present in the estuary. By c. 4500 yr BP fresh water conditions had developed at the Kaitoke Swamp site as marine influences decreased. Around the same time, fresh water swamp conditions commenced at the Police Station Swamp site on the surface of a low lying area of a Late Pleistocene dune. A sandy layer at Kaitoke may represent rapid infilling followed by a dry soil surface until c. 1000 yr BP. Conifer-hardwood forest on the hills surrounding the sites c. 7300-c. 1800 yr BP was dominated by Dacrydium and Metrosideros. During this period, environmental conditions were relatively stable, with little change in forest composition. Between 1800 yr and 800 yr BP Kaitoke Swamp was reflooded, and the Police Station Swamp extended as a shallow lake over the nearby dune flat. These new shallow swamps were invaded by swamp forest (mainly Dacrycaprus with some Laurelia). The presence of charcoal and Pteridium spores above the Kaharoa Tephra suggests that major Polynesian deforestation at northern Kaitoke began c. 600 calibrated yr BP. (author). 41 refs., 4 figs., 2 tabs

The use of environmental DNA in invasive species surveillance of the Great Lakes commercial bait trade.

Science.gov (United States)

Nathan, Lucas R; Jerde, Christopher L; Budny, Michelle L; Mahon, Andrew R

2015-04-01

Over 180 non-native species have been introduced in the Laurentian Great Lakes region, many posing threats to native species and ecosystem functioning. One potential pathway for introductions is the commercial bait trade; unknowing or unconcerned anglers commonly release unused bait into aquatic systems. Previous surveillance efforts of this pathway relied on visual inspection of bait stocks in retail shops, which can be time and cost prohibitive and requires a trained individual that can rapidly and accurately identify cryptic species. Environmental DNA (eDNA) surveillance, a molecular tool that has been used for surveillance in aquatic environments, can be used to efficiently detect species at low abundances. We collected and analyzed 576 eDNA samples from 525 retail bait shops throughout the Laurentian Great Lake states. We used eDNA techniques to screen samples for multiple aquatic invasive species (AIS) that could be transported in the bait trade, including bighead (Hypophthalmichthys nobilis) and silver carp (H. molitrix), round goby (Neogobius melanostomus), tubenose goby (Proterorhinus marmoratus), Eurasian rudd (Scardinius erythrophthalmus), and goldfish (Carassius auratus). Twenty-seven samples were positive for at least one target species (4.7% of samples), and all target species were found at least once, except bighead carp. Despite current regulations, the bait trade remains a potential pathway for invasive species introductions in the Great Lakes region. Alterations to existing management strategies regarding the collection, transportation, and use of live bait are warranted, including new and updated regulations, to prevent future introductions of invasive species in the Great Lakes via the bait trade. © 2014 Society for Conservation Biology.

Great Lakes O shore Wind Project: Utility and Regional Integration Study

Energy Technology Data Exchange (ETDEWEB)

Sajadi, Amirhossein [Case Western Reserve Univ., Cleveland, OH (United States); Loparo, Kenneth A. [Case Western Reserve Univ., Cleveland, OH (United States); D' Aquila, Robert [General Electric (GE), Albany, NY (United States); Clark, Kara [National Renewable Energy Lab. (NREL), Golden, CO (United States); Waligorski, Joseph G. [FirstEnergy, Akron, OH (United States); Baker, Scott [PJM Interconnection, Audubon, PA (United States)

2016-06-30

This project aims to identify transmission system upgrades needed to facilitate offshore wind projects as well as operational impacts of offshore generation on operation of the regional transmission system in the Great Lakes region. A simulation model of the US Eastern Interconnection was used as the test system as a case study for investigating the impact of the integration of a 1000MW offshore wind farm operating in Lake Erie into FirstEnergy/PJM service territory. The findings of this research provide recommendations on offshore wind integration scenarios, the locations of points of interconnection, wind profile modeling and simulation, and computational methods to quantify performance, along with operating changes and equipment upgrades needed to mitigate system performance issues introduced by an offshore wind project.

Elucidating causes of Diporeia decline in the Great Lakes via metabolomics: physiological responses after exposure to different stressors.

Science.gov (United States)

Maity, Suman; Jannasch, Amber; Adamec, Jiri; Watkins, James M; Nalepa, Thomas; Höök, Tomas O; Sepúlveda, Maria S

2013-01-01

The benthic macroinvertebrate Diporeia spp. have been extirpated from many areas of the Laurentian Great Lakes, but the mechanisms underlying such declines are not fully understood. Diporeia declines coinciding with the invasion of exotic dreissenid mussels (zebra and quagga) have led to the hypothesis that Diporeia declines are a result of decreased food availability from increasing competition with dreissenids for diatoms. There is additional evidence that Diporeia are negatively affected when in close proximity to dreissenids, probably because of exposure to toxins present in the mussels' pseudofeces. Diporeia are also known to be sensitive to anthropogenic contaminants (such as polychlorinated biphenyls [PCBs]) present in Great Lakes sediments. To better understand the physiological responses of Diporeia to diverse stressors, we conducted three 28-d experiments evaluating changes in the metabolomes of Diporeia (1) fed diatoms (Cyclotella meneghiniana) versus starved, (2) exposed (from Lake Michigan and Cayuga Lake) to quagga mussels (Dreissena bugensis), and (3) exposed to sediments contaminated with PCBs. The metabolomes of samples were examined using both two-dimensional gas and liquid chromatography coupled with mass spectrometry. Each stressor elicited a unique metabolome response characterized by enhanced citric acid cycle, fatty acid biosynthesis, and protein metabolism in diatom-fed Diporeia; impaired glycolysis, protein catabolism, and folate metabolism in Diporeia from Lake Michigan irrespective of quagga mussel exposure, suggesting lake-specific adaptation mechanisms; and altered cysteine and phospholipid metabolism during PCB exposure. Subsequent comparisons of these stressor-specific metabolic responses with metabolomes of a feral Diporeia population would help identify stressors affecting Diporeia populations throughout the Great Lakes.

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

Science.gov (United States)

Gorman, Owen T.

2012-01-01

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

Application of the North American Multi-Model Ensemble to seasonal water supply forecasting in the Great Lakes basin through the use of the Great Lakes Seasonal Climate Forecast Tool

Science.gov (United States)

Gronewold, A.; Apps, D.; Fry, L. M.; Bolinger, R.

2017-12-01

The U.S. Army Corps of Engineers (USACE) contribution to the internationally coordinated 6-month forecast of Great Lakes water levels relies on several water supply models, including a regression model relating a coming month's water supply to past water supplies, previous months' precipitation and temperature, and forecasted precipitation and temperature. Probabilistic forecasts of precipitation and temperature depicted in the Climate Prediction Center's seasonal outlook maps are considered to be standard for use in operational forecasting for seasonal time horizons, and have provided the basis for computing a coming month's precipitation and temperature for use in the USACE water supply regression models. The CPC outlook maps are a useful forecast product offering insight into interpretation of climate models through the prognostic discussion and graphical forecasts. However, recent evolution of USACE forecast procedures to accommodate automated data transfer and manipulation offers a new opportunity for direct incorporation of ensemble climate forecast data into probabilistic outlooks of water supply using existing models that have previously been implemented in a deterministic fashion. We will present results from a study investigating the potential for applying data from the North American Multi-Model Ensemble to operational water supply forecasts. The use of NMME forecasts is facilitated by a new, publicly available, Great Lakes Seasonal Climate Forecast Tool that provides operational forecasts of monthly average temperatures and monthly total precipitation summarized for each lake basin.

Hierarchical multi-scale classification of nearshore aquatic habitats of the Great Lakes: Western Lake Erie

Science.gov (United States)

McKenna, J.E.; Castiglione, C.

2010-01-01

Classification is a valuable conservation tool for examining natural resource status and problems and is being developed for coastal aquatic habitats. We present an objective, multi-scale hydrospatial framework for nearshore areas of the Great Lakes. The hydrospatial framework consists of spatial units at eight hierarchical scales from the North American Continent to the individual 270-m spatial cell. Characterization of spatial units based on fish abundance and diversity provides a fish-guided classification of aquatic areas at each spatial scale and demonstrates how classifications may be generated from that framework. Those classification units then provide information about habitat, as well as biotic conditions, which can be compared, contrasted, and hierarchically related spatially. Examples within several representative coastal or open water zones of the Western Lake Erie pilot area highlight potential application of this classification system to management problems. This classification system can assist natural resource managers with planning and establishing priorities for aquatic habitat protection, developing rehabilitation strategies, or identifying special management actions.

Analysis of ERS 1 synthetic aperture radar data of frozen lakes in northern Montana and implications for climate studies

Science.gov (United States)

Hall, Dorothy K.; Fagre, Daniel B.; Klasner, Fritz; Linebaugh, Gregg; Liston, Glen E.

1994-01-01

Lakes that freeze each winter are good indicators of regional climate change if key parameters, such as freeze-up and breakup date and maximum ice thickness, are measured over a decade-scale time frame. Synthetic aperture radar (SAR) satellite data have proven to be especially useful for measurement of climatologically significant parameters characteristic of frozen lakes. In this paper, five lakes in Glacier National Park, Montana, have been studied both in the field and using Earth Remote-Sensing Satellite (ERS) 1 SAR data during the 1992-1993 winter. The lakes are characterized by clear ice, sometimes with tubular or rounded bubbles, and often with a layer of snow ice on top of the clear ice. They are also often snow covered. Freeze-up is detected quite easily using ERS 1 SAR data as soon as a thin layer of ice forms. The effect of snow ice on the backscatter is thought to be significant but is, as yet, undetermined. On the five lakes studied, relative backscatter was found to increase with ice thickness until a maximum was reached in February. Breakup, an often ill-defined occurrence, is difficult to detect because surface water causes the SAR signal to be absorbed, thus masking the ice below. Comparison of the bubble structure of thaw lakes in northern Alaska with lakes in northern Montana has shown that the ice structure is quite different, and this difference may contribute to differential SAR signature evolution in the lakes of the two areas.

Habitat capacity for cougar recolonization in the Upper Great Lakes region.

Science.gov (United States)

O Neil, Shawn T; Rahn, Kasey C; Bump, Joseph K

2014-01-01

Recent findings indicate that cougars (Puma concolor) are expanding their range into the midwestern United States. Confirmed reports of cougar in Michigan, Minnesota, and Wisconsin have increased dramatically in frequency during the last five years, leading to speculation that cougars may re-establish in the Upper Great Lakes (UGL) region, USA. Recent work showed favorable cougar habitat in northeastern Minnesota, suggesting that the northern forested regions of Michigan and Wisconsin may have similar potential. Recolonization of cougars in the UGL states would have important ecological, social, and political impacts that will require effective management. Using Geographic Information Systems (GIS), we extended a cougar habitat model to Michigan and Wisconsin and incorporated primary prey densities to estimate the capacity of the region to support cougars. Results suggest that approximately 39% (>58,000 km2) of the study area could support cougars, and that there is potential for a population of approximately 500 or more animals. An exploratory validation of this habitat model revealed strong association with 58 verified cougar locations occurring in the study area between 2008 and 2013. Spatially explicit information derived from this study could potentially lead to estimation of a viable population, delineation of possible cougar-human conflict areas, and the targeting of site locations for current monitoring. Understanding predator-prey interactions, interspecific competition, and human-wildlife relationships is becoming increasingly critical as top carnivores continue to recolonize the UGL region.

Habitat capacity for cougar recolonization in the Upper Great Lakes region.

Directory of Open Access Journals (Sweden)

Shawn T O Neil

Full Text Available BACKGROUND: Recent findings indicate that cougars (Puma concolor are expanding their range into the midwestern United States. Confirmed reports of cougar in Michigan, Minnesota, and Wisconsin have increased dramatically in frequency during the last five years, leading to speculation that cougars may re-establish in the Upper Great Lakes (UGL region, USA. Recent work showed favorable cougar habitat in northeastern Minnesota, suggesting that the northern forested regions of Michigan and Wisconsin may have similar potential. Recolonization of cougars in the UGL states would have important ecological, social, and political impacts that will require effective management. METHODOLOGY/PRINCIPAL FINDINGS: Using Geographic Information Systems (GIS, we extended a cougar habitat model to Michigan and Wisconsin and incorporated primary prey densities to estimate the capacity of the region to support cougars. Results suggest that approximately 39% (>58,000 km2 of the study area could support cougars, and that there is potential for a population of approximately 500 or more animals. An exploratory validation of this habitat model revealed strong association with 58 verified cougar locations occurring in the study area between 2008 and 2013. CONCLUSIONS/SIGNIFICANCE: Spatially explicit information derived from this study could potentially lead to estimation of a viable population, delineation of possible cougar-human conflict areas, and the targeting of site locations for current monitoring. Understanding predator-prey interactions, interspecific competition, and human-wildlife relationships is becoming increasingly critical as top carnivores continue to recolonize the UGL region.

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-05-17

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

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

International Nuclear Information System (INIS)

Kelly, Jocelyn M.; Janz, David M.

2009-01-01

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

Spatial distribution and trends of total mercury in waters of the Great Lakes and connecting channels using an improved sampling technique

International Nuclear Information System (INIS)

Dove, A.; Hill, B.; Klawunn, P.; Waltho, J.; Backus, S.; McCrea, R.C.

2012-01-01

Environment Canada recently developed a clean method suitable for sampling trace levels of metals in surface waters. The results of sampling for total mercury in the Laurentian Great Lakes between 2003 and 2009 give a unique basin-wide perspective of concentrations of this important contaminant and represent improved knowledge of mercury in the region. Results indicate that concentrations of total mercury in the offshore regions of the lakes were within a relatively narrow range from about 0.3 to 0.8 ng/L. The highest concentrations were observed in the western basin of Lake Erie and concentrations then declined towards the east. Compared to the offshore, higher levels were observed at some nearshore locations, particularly in lakes Erie and Ontario. The longer-term temporal record of mercury in Niagara River suspended sediments indicates an approximate 30% decrease in equivalent water concentrations since 1986. - Highlights: ► Basin-wide concentrations of total mercury in Great Lakes surface waters are provided for the first time. ► A clean sampling method is described, stressing isolation of the sample from extraneous sources of contamination. ► Sub-ng/L concentrations of total mercury are observed in most Great Lakes offshore areas. ► Concentrations in the western basin of Lake Erie are consistently the highest observed in the basin. ► The longer-term record of mercury in Niagara River suspended sediments indicates an approximate 30% decrease since 1986. - A new, clean sampling method for metals is described and basin-wide measurements of total mercury are provided for Great Lakes surface waters for the first time.

Evaluation of ERTS data for certain oceanographic uses. [upwelling, water circulation, and pollution in Great Lakes

Science.gov (United States)

Strong, A. E. (Principal Investigator)

1973-01-01

The author has identified the following significant results. Upwelling along the eastern shore of Lake Michigan was occurring during the 3 and 21 August 1973 visits by ERTS-1. The NOAA-2 VHRR thermal-IR data are being digitized for comparison. Early indications are that these upwellings induced a calcium carbonate precipitate to form in the surface waters. It is most pronounced in the MSS-4 channel. On the lake bottom this jell-like sediment is known as marl and adds to the eutrophication of the lake. This phenomenon may help to explain the varve-like nature of bottom cores that have been observed in the Great Lakes.

Great cormorant (Phalacrocorax carbo predation on pikeperch (Sander lucioperca L. in shallow eutrophic lakes in Poland

Directory of Open Access Journals (Sweden)

Traczuk Piotr

2017-06-01

Full Text Available Increases in the population abundance of the piscivorous great cormorant (Phalacrocorax carbo has led to conflicts with fisheries. Cormorants are blamed for decreased fish catches in many lakes in Poland. The aim of this paper is to describe to role of pikeperch (Sander lucioperca in the diet of cormorants nesting in a colony on the island in Lake Warnołty. Since the breeding colony is located in the vicinity of Lake OEniardwy, the largest lake in Poland, the cormorants use the resources in this lake. In 2009-2016, 18,432 regurgitated fish were collected, of which 593 were pikeperch. The share of pikeperch among fish collected in 2009-2012 did not exceed 2%, but from 2013 this increased substantially to maximum of 38.2% in 2015. The smallest pikeperch had a standard length of 8.4 cm, and the largest 42.5 cm. Pikeperch mean length differed by year, and the length distribution was close to normal. The sizes of the regurgitated pikeperch indicate that cormorants prey almost exclusively on juvenile specimens. The results of the present study indicate that cormorant predation has a significant impact on pikeperch populations in lakes in the vicinity of the colony, and the great cormorants are possibly a significant factor in the effectiveness of pikeperch management. When planning for the management of fish populations in lakes subjected to cormorant predation pressure, it should be borne in mind that predation by this piscivorous bird species impacts the abundance and size-age structure of fish populations.

Preliminary Nearshore Sedimentation Rate Analysis of the Tuungane Project Northern Mahale Conservation Area, Lake Tanganyika (Tanzania)

Science.gov (United States)

Smiley, R. A.; McGlue, M. M.; Yeager, K. M.; Soreghan, M. J.; Lucas, J.; Kimirei, I.; Mbonde, A.; Limbu, P.; Apse, C.

2017-12-01

The combined effects of climate change, overfishing, and sediment pollution are altering Lake Tanganyika's littoral fisheries in profoundly negative ways. One method for conserving critical fish resources and safeguarding biodiversity in Lake Tanganyika is by establishing small-scale nearshore protected zones, which can be administrated by lakeshore villagers organized into beach management units (BMUs). Each BMU endeavors to manage offshore "no-catch" protected zones, prohibit the use of illegal fishing gear, and promote sustainable agriculture that abates erosion in the lake watershed, in order to mitigate sediment pollution in the lake. We adopted a limnogeological approach to assist in characterizing the littoral zone associated with BMUs in the northern Mahale region of Lake Tanganyika (Tanzania), a critical conservation area for the Nature Conservancy's Tuungane Project (https://www.nature.org/ourinitiatives/regions/africa/wherewework/tuungane-project.xml). We hypothesized that BMUs with heavy onshore agricultural activity would experience relatively high offshore sedimentation rates, due to enhanced sediment-laden runoff in the wet season. Such changes are predicted to alter benthic substrates and degrade habitat available for fish spawning. We mapped bathymetry and sediment types along a 29 km2 area of the littoral zone using high-resolution geophysical tools, and assessed short-term sedimentation rates using sediment cores and radionuclide geochronology (210Pb). Initial results from 210Pb analyses show that sedimentation rates at the mud-line ( 85-100 m water depth) are relatively slow but spatially variable in the northern Mahale area. Offshore of the Kalilani village BMU, linear sedimentation rates are 0.50 mm/yr. By contrast, sedimentation rates offshore from the Igualula village BMU are 0.90-1.30 mm/yr. Higher sedimentation rates near Igualula are consistent with greater sediment inputs from the nearby Lagosa River and its watershed, which has been

Lake Afrera, a structural depression in the Northern Afar Rift (Red Sea).

Science.gov (United States)

Bonatti, Enrico; Gasperini, Elia; Vigliotti, Luigi; Lupi, Luca; Vaselli, Orlando; Polonia, Alina; Gasperini, Luca

2017-05-01

The boundary between the African and Arabian plates in the Southern Red Sea region is displaced inland in the northern Afar rift, where it is marked by the Red Sea-parallel Erta Ale, Alaita, and Tat Ali volcanic ridges. The Erta Ale is offset by about 20 and 40 km from the two en echelon ridges to the south. The offset area is highly seismic and marked by a depression filled by lake Afrera, a saline body of water fed by hydrothermal springs. Acoustic bathymetric profiles show ≈80 m deep canyons parallel to the NNW shore of the lake, part of a system of extensional normal faults striking parallel to the Red Sea. This system is intersected by oblique structures, some with strike-slip earthquakes, in what might evolve into a transform boundary. Given that the lake's surface lies today about 112 m below sea level, the depressed (minus ≈190 m below sea level) lake's bottom area may be considered the equivalent of the "nodal deep" in slow-slip oceanic transforms. The chemistry of the lake is compatible with the water having originated from hydrothermal liquids that had reacted with evaporites and basalts, rather than residual from evaporation of sea water. Bottom sediments include calcitic grains, halite and gypsum, as well as ostracod and diatom tests. The lake's level appears to have dropped by over 10 m during the last ≈50 years, continuing a drying up trend of the last few thousand years, after a "wet" stage 9,800 and 7,800 years before present when according to Gasse (1973) Lake Afrera covered an area several times larger than at present. This "wet" stage corresponds to an early Holocene warm-humid climate that prevailed in Saharan and Sub Saharan Africa. Lake Abhé, located roughly 250 km south of Afrera, shows similar climate-driven oscillations of its level.

Saline systems of the Great Plains of western Canada: an overview of the limnogeology and paleolimnology

Science.gov (United States)

Last, William M; Ginn, Fawn M

2005-01-01

In much of the northern Great Plains, saline and hypersaline lacustrine brines are the only surface waters present. As a group, the lakes of this region are unique: there is no other area in the world that can match the concentration and diversity of saline lake environments exhibited in the prairie region of Canada and northern United States. The immense number of individual salt lakes and saline wetlands in this region of North America is staggering. Estimates vary from about one million to greater than 10 million, with densities in some areas being as high as 120 lakes/km2. Despite over a century of scientific investigation of these salt lakes, we have only in the last twenty years advanced far enough to appreciate the wide spectrum of lake types, water chemistries, and limnological processes that are operating in the modern settings. Hydrochemical data are available for about 800 of the lake brines in the region. Composition, textural, and geochemical information on the modern bottom sediments has been collected for just over 150 of these lakes. Characterization of the biological and ecological features of these lakes is based on even fewer investigations, and the stratigraphic records of only twenty basins have been examined. The lake waters show a considerable range in ionic composition and concentration. Early investigators, concentrating on the most saline brines, emphasized a strong predominance of Na+ and SO4-2 in the lakes. It is now realized, however, that not only is there a complete spectrum of salinities from less than 1 ppt TDS to nearly 400 ppt, but also virtually every water chemistry type is represented in lakes of the region. With such a vast array of compositions, it is difficult to generalize. Nonetheless, the paucity of Cl-rich lakes makes the northern Great Plains basins somewhat unusual compared with salt lakes in many other areas of the world (e.g., Australia, western United States). Compilations of the lake water chemistries show distinct

Classification and Accuracy Assessment for Coarse Resolution Mapping within the Great Lakes Basin, USA

Science.gov (United States)

This study applied a phenology-based land-cover classification approach across the Laurentian Great Lakes Basin (GLB) using time-series data consisting of 23 Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) composite images (250 ...

77 FR 38803 - Request for Nominations to the Great Lakes Advisory Board (GLAB)

Science.gov (United States)

2012-06-29

... affiliations and other considerations); Demonstrated experience with Great Lakes issues; Leadership experience... nominees will include: The background and experiences that would help members contribute to the diversity... the nominee's experience and knowledge will bring value to the work of the GLAB. To help the Agency in...

Can We Drink the Water? Data Sharing Lessons From the Great Lakes

Science.gov (United States)

Aufdenkampe, A. K.; Paige, K.; Slawecki, T. A.

2017-12-01

The Great Lakes Observing System (GLOS) is one of 11 regional associations of the Integrated Ocean Observing System (IOOS). Over time, GLOS has built a reputation as a trusted data aggregator and resource for managers, policy makers and recreational boaters in the region. This was evidenced best when, in response to the 2014 Lake Erie harmful algal bloom event, local stakeholders including universities, state government, and municipal water managers turned to GLOS as a repository for sharing and finding data. The IOOS Certification process, required under the authority of the Integrated Coastal and Ocean Observation System Act of 2009 (ICOOS Act), further legitimizes these data assembly centers that serve as valuable coordinators of data for their regions.

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

Science.gov (United States)

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

2010-01-01

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

Assessing potential impacts of climate change and variability on the Great Lakes-St. Lawrence Basin: A binational approach

International Nuclear Information System (INIS)

Quinn, F.H.; Mortsch, L.D.

1997-01-01

The potential impacts of climate change and variability on the Great Lakes environment are serious and complex. The Great Lakes-St. Lawrence Basin is home to 42.5 million US and Canadian citizens and is the industrial and commercial heartland of both nations. The region is rich in human and natural resources, with diverse economic activities and substantial infrastructure which would be affected by major shifts in climate. For example, water level changes could affect wetland distribution and functioning; reductions in streamflow would alter assimilative capacities while warmer water temperatures would influence spring and fall turnover and incidence of anoxia. A binational program has been initiated to conduct interdisciplinary, integrated impact assessments for the Great Lakes-St. Lawrence River Basin. The goal of this program is to undertake interdisciplinary, integrated studies to improve the understanding of the complex interactions between climate, the environment, and socioeconomic systems in order to develop informed regional adaptation responses

Glacial dispersal and flow history, East Arm area of Great Slave Lake, NWT, Canada

Science.gov (United States)

Sharpe, D. R.; Kjarsgaard, B. A.; Knight, R. D.; Russell, H. A. J.; Kerr, D. E.

2017-06-01

Little work has been completed on paleo-ice-sheet flow indicators of the Laurentide Ice Sheet, west of the Keewatin Ice Divide. Field mapping, sampling and analysis of glaciogenic sediment (∼500 sample sites) in a ∼33,000 km2 region near the East Arm of Great Slave Lake in northwestern Canada, provided a rare opportunity to improve understanding of sediment erosion and transport patterns. Glacially-eroded bedrock and sedimentary landforms record east to west flow with NW and SW divergence, mapped within a portion of the Great Slave Lake flow tract. Transported till reflects a similar divergent flow pattern based on dispersal geometries for multiple indicators (e.g., heavy minerals and lithic fragments), which are aligned with the dominant and latest ice flow direction. Glaciofluvial erosion (e.g., s-forms and till removal), transport, and deposition (mainly as esker sediment) are set within 0.3-3 km wide meltwater erosional corridors, spaced regularly at 10-15 km intervals. Transport paths and distances are comparable in till and esker sediment, however, distances appear to be greater (∼5-25 km) in some esker constituents and indicator minerals are typically more concentrated in esker sediment than in till. Corridors form a divergent array identical to the pattern of ice-flow features. The congruence of ice and meltwater flow features is interpreted to be a response to a similar ice sheet gradient, and close timing of events (late dominant glacial ice flow and meltwater flow). The similarity in glacial and glaciofluvial flow patterns has important ramifications for event reconstruction and for exploration geologists utilizing mineral and geochemical tracing methods in this region, and possibly other parts of northern Canada. The correspondence between East Arm dispersal patterns, landforms and flow indicators supports interpretation of a simple and predictable single flow divergence model. This is in contrast to previous, multi-flow models, in which fan

Significance of population centers as sources of gaseous and dissolved PAHs in the lower Great Lakes.

Science.gov (United States)

McDonough, Carrie A; Khairy, Mohammed A; Muir, Derek C G; Lohmann, Rainer

2014-07-15

Polyethylene passive samplers (PEs) were used to measure concentrations of gaseous and dissolved polycyclic aromatic hydrocarbons (PAHs) in the air and water throughout the lower Great Lakes during summer and fall of 2011. Atmospheric Σ15PAH concentrations ranged from 2.1 ng/m3 in Cape Vincent (NY) to 76.4 ng/m3 in downtown Cleveland (OH). Aqueous Σ18PAH concentrations ranged from 2.4 ng/L at an offshore Lake Erie site to 30.4 ng/L in Sheffield Lake (OH). Gaseous PAH concentrations correlated strongly with population within 3-40 km of the sampling site depending on the compound considered, suggesting that urban centers are a primary source of gaseous PAHs (except retene) in the lower Great Lakes region. The significance of distant population (within 20 km) versus local population (within 3 km) increased with subcooled liquid vapor pressure. Most dissolved aqueous PAHs did not correlate significantly with population, nor were they consistently related to river discharge, wastewater effluents, or precipitation. Air-water exchange calculations implied that diffusive exchange was a source of phenanthrene to surface waters, while acenaphthylene volatilized out of the lakes. Comparison of air-water fluxes with temperature suggested that the significance of urban centers as sources of dissolved PAHs via diffusive exchange may decrease in warmer months.

Systems approach to detect and evaluate contaminants of emerging concern in the Great Lakes

Science.gov (United States)

The release of chemicals of emerging concern threatens near shore health in the Great Lakes, particularly in regions already suffering from degradation of water and environmental quality due to past and present anthropogenic activities. Critical issues remain in delisting Areas ...

Remotely Sensing Lake Water Volumes on the Inner Arctic Coastal Plain of Northern Alaska

Science.gov (United States)

Simpson, C. E.; Arp, C. D.; Jones, B. M.; Hinkel, K. M.; Carroll, M.; Smith, L. C.

2017-12-01

Thermokarst lake depth is controlled by the amount of excess ice in near-surface permafrost, with lake depths of about 1 - 3 m in areas of epigenetic permafrost and over 10 m in areas of syngenetic permafrost. An important exception to these general patterns is found on the inner Arctic Coastal Plain (ACP) of northern Alaska, where deep lakes occur in Pleistocene-aged, ground-ice poor sandy terrain. These lakes cover 20% of the currently inactive sand sheet and dune deposit (referred to as the Pleistocene Sand Sea) that comprises approximately 7000 km2 of the ACP. Surrounded by high and eroding bluffs, sand sea lakes lie in natural depressions and are characterized by wide, shallow littoral shelves and central troughs that are typically oriented NNW to SSE and can reach depths greater than 20 m. Despite their unique form and extensive coverage, these lakes have received little prior study and a literature gap remains regarding regional water storage. This research classifies sand sea lakes, estimates individual lake volume, and provides a first quantification of water storage in a region of the lake-dominated ACP. We measured bathymetric profiles in 19 sand sea lakes using a sonar recorder to capture various lake depth gradients. Bathymetric surveys collected by oil industry consultants, lake monitoring programs, and habitat studies serve as additional datasets. These field measured lake depth data points were used to classify Color Infrared Photography, WorldView-2 satellite imagery, and Landsat-OLI satellite imagery to develop a spectral depth-classification algorithm and facilitate the interpolation of the bathymetry for study lakes in the inner ACP. Finally, we integrate the remotely sensed bathymetry and imagery-derived lake surface area to estimate individual and regional-scale lake volume. In addition to the natural function of these lakes in water storage, energy balance, and habitat provision, the need for winter water supply to build ice roads for oil

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...

Deep Learning Methods for Quantifying Invasive Benthic Species in the Great Lakes

Science.gov (United States)

Billings, G.; Skinner, K.; Johnson-Roberson, M.

2017-12-01

In recent decades, invasive species such as the round goby and dreissenid mussels have greatly impacted the Great Lakes ecosystem. It is critical to monitor these species, model their distribution, and quantify the impacts on the native fisheries and surrounding ecosystem in order to develop an effective management response. However, data collection in underwater environments is challenging and expensive. Furthermore, the round goby is typically found in rocky habitats, which are inaccessible to standard survey techniques such as bottom trawling. In this work we propose a robotic system for visual data collection to automatically detect and quantify invasive round gobies and mussels in the Great Lakes. Robotic platforms equipped with cameras can perform efficient, cost-effective, low-bias benthic surveys. This data collection can be further optimized through automatic detection and annotation of the target species. Deep learning methods have shown success in image recognition tasks. However, these methods often rely on a labelled training dataset, with up to millions of labelled images. Hand labeling large numbers of images is expensive and often impracticable. Furthermore, data collected in the field may be sparse when only considering images that contain the objects of interest. It is easier to collect dense, clean data in controlled lab settings, but this data is not a realistic representation of real field environments. In this work, we propose a deep learning approach to generate a large set of labelled training data realistic of underwater environments in the field. To generate these images, first we draw random sample images of individual fish and mussels from a library of images captured in a controlled lab environment. Next, these randomly drawn samples will be automatically merged into natural background images. Finally, we will use a generative adversarial network (GAN) that incorporates constraints of the physical model of underwater light propagation

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

Directory of Open Access Journals (Sweden)

Douglas C. Tozer

2016-12-01

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

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

Science.gov (United States)

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

2000-01-01

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

Transfer of Telegraph Technology to China: The Role of The Great northern Telegraph Company 1870-1890

DEFF Research Database (Denmark)

Baark, Erik

This report examines the historical events surrounding the introduction of telegraph technology in China by the Danish Great Northern Telegraph Company. It describes the influence of Great Northern on diplomatic relations between Denmark and China during the decades of the 1870s and 1880s......, and the contributions in terms of the establishment of telegraph schools and development of a Chinese telegraph code that this company made as part of the technology transfer process....

Stimulating a Great Lakes coastal wetland seed bank using portable cofferdams: implications for habitat rehabilitation

Science.gov (United States)

Kowalski, K.P.; Wilcox, D.A.; Wiley, M.J.

2009-01-01

Coastal wetland seed banks exposed by low lake levels or through management actions fuel the reestablishment of emergent plant assemblages (i.e., wetland habitat) critical to Great Lakes aquatic biota. This project explored the effectiveness of using portable, water-filled cofferdams as a management tool to promote the natural growth of emergent vegetation from the seed bank in a Lake Erie coastal wetland. A series of dams stretching approximately 450??m was installed temporarily to isolate hydrologically a 10-ha corner of the Crane Creek wetland complex from Lake Erie. The test area was dewatered in 2004 to mimic a low-water year, and vegetation sampling characterized the wetland seed bank response at low, middle, and high elevations in areas open to and protected from bird and mammal herbivory. The nearly two-month drawdown stimulated a rapid seed-bank-driven response by 45 plant taxa. Herbivory had little effect on plant species richness, regardless of the location along an elevation gradient. Inundation contributed to the replacement of immature emergent plant species with submersed aquatic species after the dams failed and were removed prematurely. This study revealed a number of important issues that must be considered for effective long-term implementation of portable cofferdam technology to stimulate wetland seed banks, including duration of dewatering, product size, source of clean water, replacement of damaged dams, and regular maintenance. This technology is a potentially important tool in the arsenal used by resource managers seeking to rehabilitate the functions and values of Great Lakes coastal wetland habitats.

Monitoring Agricultural Cropping Patterns across the Laurentian Great Lakes Basin Using MODIS-NDVI Data

Science.gov (United States)

The Moderate Resolution Imaging Spectrometer (MODIS) Normalized Difference Vegetation Index (NDVI) 16-day composite data product (MOD12Q) was used to develop annual cropland and crop-specific map products (corn, soybeans, and wheat) for the Laurentian Great Lakes Basin (GLB). Th...

Chemicals of emerging concern in the Great Lakes Basin: an analysis of environmental exposures.

Science.gov (United States)

Klecka, Gary; Persoon, Carolyn; Currie, Rebecca

2010-01-01

This review and statistical analysis was conducted to better understand the nature and significance of environmental exposures in the Great Lakes Basin and watershed to a variety of environmental contaminants. These contaminants of interest included current-use pesticides, pharmaceuticals, organic wastewater contaminants, alkylphenol ethoxylates, perfluorinated surfactants, flame retardants, and chlorinated paraffins. The available literature was critically reviewed and used to develop a database containing 19,611 residue values for 326 substances. In many papers, sampling locations were characterized as being downstream from municipal wastewater discharges, receiving waters for industrial facilities, areas susceptible to agricultural or urban contamination, or harbors and ports. To develop an initial assessment of their potential ecological significance, the contamination levels found were compared with currently available regulatory standards, guidelines, or criteria. This review was prepared for the IJC multi-board work group, and served as background material for an expert consultation, held in March, 2009, in which the significance of the contaminants found was discussed. Moreover, the consultation attempted to identify and assess opportunities for strengthening future actions that will protect the Great Lakes. Based on the findings and conclusions of the expert consultation, it is apparent that a wide variety of chemicals of emerging concern have been detected in environmental media (air, water, sediment, biota) from the Great Lakes Basin, although many are present at only trace levels. Although the presence of these contaminants raises concerns in the public and among the scientific community, the findings must be placed in context. Significant scientific interpretation is required to understand the extent to which these chemicals may pose a threat to the ecosystem and to human health. The ability to detect chemicals in environmental media greatly surpasses

Life under ice: Investigating microbial-related biogeochemical cycles in the seasonally-covered Great Lake Onego, Russia

Science.gov (United States)

Thomas, Camille; Ariztegui, Daniel; Victor, Frossard; Emilie, Lyautey; Marie-Elodie, Perga; Life Under Ice Scientific Team

2016-04-01

The Great European lakes Ladoga and Onego are important resources for Russia in terms of drinking water, energy, fishing and leisure. Because their northern location (North of Saint Petersburgh), these lakes are usually ice-covered during winter. Due to logistical reasons, their study has thus been limited to the ice-free periods, and very few data are available for the winter season. As a matter of fact, comprehension of large lakes behaviour in winter is very limited as compared to the knowledge available from small subpolar lakes or perennially ice-covered polar lakes. To tackle this issue, an international consortium of scientists has gathered around the « life under ice » project to investigate physical, chemical and biogeochemical changes during winter in Lake Onego. Our team has mainly focused on the characterization and quantification of biological processes, from the water column to the sediment, with a special focus on methane cycling and trophic interactions. A first « on-ice » campaign in March 2015 allowed the sampling of a 120 cm sedimentary core and the collection of water samples at multiple depths. The data resulting from this expedition will be correlated to physical and chemical parameters collected simultaneously. A rapid biological activity test was applied immediately after coring in order to test for microbial activity in the sediments. In situ adenosine-5'-triphosphate (ATP) measurements were carried out in the core and taken as an indication of living organisms within the sediments. The presence of ATP is a marker molecule for metabolically active cells, since it is not known to form abiotically. Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) were extracted from these samples, and quantified. Quantitative polymerase chain reactions (PCR) were performed on archaeal and bacterial 16S rRNA genes used to reconstruct phylogenies, as well as on their transcripts. Moreover, functional genes involved in the methane and nitrogen cycles

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

Science.gov (United States)

Gorman, Owen T.; Weidel, Brian C.

2014-01-01

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

The sterile-male-release technique in Great Lakes sea lamprey management

Science.gov (United States)

Twohey, Michael B.; Heinrich, John W.; Seelye, James G.; Fredricks, Kim T.; Bergstedt, Roger A.; Kaye, Cheryl A.; Scholefield, Ron J.; McDonald, Rodney B.; Christie, Gavin C.

2003-01-01

The implementation of a sterile-male-release technique from 1991 through 1999 and evaluation of its effectiveness in the Great Lakes sea lamprey (Petromyzon marinus) management program is reviewed. Male sea lampreys were injected with the chemosterilant bisazir (P,P-bis(1-aziridinyl)-N-methylphosphinothioic amide) using a robotic device. Quality assurance testing indicated the device delivered a consistent and effective dose of bisazir. Viability of embryos in an untreated control group was 64% compared to 1% in a treatment group. A task force developed nine hypotheses to guide implementation and evaluation of the technique. An annual average of 26,000 male sea lampreys was harvested from as many as 17 Great Lakes tributaries for use in the technique. An annual average of 16,100 sterilized males was released into 33 tributaries of Lake Superior to achieve a theoretical 59% reduction in larval production during 1991 to 1996. The average number of sterile males released in the St. Marys River increased from 4,000 during 1991 to 1996 to 20,100 during 1997 to 1999. The theoretical reduc-stertion in reproduction when combined with trapping was 57% during 1991 to 1996 and 86% during 1997 to 1999. Evaluation studies demonstrated that sterilized males were competitive and reduced production of larvae in streams. Field studies and simulation models suggest reductions in reproduction will result in fewer recruits, but there is risk of periodic high recruitment events independent of sterile-male release. Strategies to reduce reproduction will be most reliable when low densities of reproducing females are achieved. Expansion of the technique is limited by access to additional males for sterilization. Sterile-male release and other alternative controls are important in delivering integrated pest management and in reducing reliance on pesticides.

Monitoring Agricultural Cropping Patterns in the Great Lakes Basin Using MODIS-NDVI Time Series Data

Science.gov (United States)

This research examined changes in agricultural cropping patterns across the Great Lakes Basin (GLB) using the Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) data. Specific research objectives were to characterize the distribut...

Are Predators Limiting Zebra Mussel Colonization of Unionid Mussels in Great Lake Coastal Wetlands?

Science.gov (United States)

de Szalay, F. A.; Bowers, R.

2005-05-01

Although many native mollusc populations have been eliminated in the Laurentian Great Lakes by the exotic zebra mussel, recent surveys have found abundant unionid (Bivalvia: Unionidae) populations in some coastal wetlands. Unionid burrowing in soft sediments and predation by fish have been shown to reduce numbers of attached zebra mussels, and we tested these factors in a Lake Erie coastal wetland. In 2002, we held live unionids (Leptodea fragilis, Quadrula quadrula) and Pyganodon grandis shells in exclosures with wire mesh bottoms that were buried to sediment depths of either 5, 10, or 20 cm. After 2 months, numbers of attached dreissenids on unionids were significantly higher inside all exclosure treatments than outside exclosures. This indicated that either unionid burrowing was prevented in all sediment depth treatments or molluscivores were excluded by exclosures. In 2004, we measured dreissenid colonization on Q. quadrula and PVC plates in bottomless exclosures with different mesh sizes. After 6 months, dreissenid numbers on PVC plates and on Q. quadrula in 2.5 cm X 2.5 cm and 5 cm X 10 cm mesh exclosures were significantly higher than in open exclosures. These data suggest that molluscivores are important in limiting dreissenids in Great Lake coastal wetlands.

Association of toxin-producing Clostridium botulinum with the macroalga Cladophora in the Great Lakes.

Science.gov (United States)

Chun, Chan Lan; Ochsner, Urs; Byappanahalli, Muruleedhara N; Whitman, Richard L; Tepp, William H; Lin, Guangyun; Johnson, Eric A; Peller, Julie; Sadowsky, Michael J

2013-03-19

Avian botulism, a paralytic disease of birds, often occurs on a yearly cycle and is increasingly becoming more common in the Great Lakes. Outbreaks are caused by bird ingestion of neurotoxins produced by Clostridium botulinum, a spore-forming, gram-positive, anaerobe. The nuisance, macrophytic, green alga Cladophora (Chlorophyta; mostly Cladophora glomerata L.) is a potential habitat for the growth of C. botulinum. A high incidence of botulism in shoreline birds at Sleeping Bear Dunes National Lakeshore (SLBE) in Lake Michigan coincides with increasingly massive accumulations of Cladophora in nearshore waters. In this study, free-floating algal mats were collected from SLBE and other shorelines of the Great Lakes between June and October 2011. The abundance of C. botulinum in algal mats was quantified and the type of botulism neurotoxin (bont) genes associated with this organism were determined by using most-probable-number PCR (MPN-PCR) and five distinct bont gene-specific primers (A, B, C, E, and F). The MPN-PCR results showed that 16 of 22 (73%) algal mats from the SLBE and 23 of 31(74%) algal mats from other shorelines of the Great Lakes contained the bont type E (bont/E) gene. C. botulinum was present up to 15000 MPN per gram dried algae based on gene copies of bont/E. In addition, genes for bont/A and bont/B, which are commonly associated with human diseases, were detected in a few algal samples. Moreover, C. botulinum was present as vegetative cells rather than as dormant spores in Cladophora mats. Mouse toxin assays done using supernatants from enrichment of Cladophora containing high densities of C. botulinum (>1000 MPN/g dried algae) showed that Cladophora-borne C. botulinum were toxin-producing species (BoNT/E). Our results indicate that Cladophora provides a habitat for C. botulinum, warranting additional studies to better understand the relationship between this bacterium and the alga, and how this interaction potentially contributes to botulism

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

Directory of Open Access Journals (Sweden)

Isaac WONG

2010-08-01

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

Assessing the Accuracy of MODIS-NDVI Derived Land-Cover Across the Great Lakes Basin

Science.gov (United States)

This research describes the accuracy assessment process for a land-cover dataset developed for the Great Lakes Basin (GLB). This land-cover dataset was developed from the 2007 MODIS Normalized Difference Vegetation Index (NDVI) 16-day composite (MOD13Q) 250 m time-series data. Tr...

Small mammals in successional prairie woodlands of the northern Great Plains

Science.gov (United States)

Mark A. Rumble; John E. Gobeille

2001-01-01

Prairie woodlands comprise about 1 percent of the landscape in the northern Great Plains. However, prairie woodlands provide habitat for far more than 1 percent of the wildlife species that occur in the prairie region. With increasing pressures on natural resources, managers need methods for managing wildlife habitat and biodiversity that are based on ecological...

Mercury Sources and Cycling in the Great Lakes: Dramatic Changes Resulting from Altered Atmospheric Loads and the Near-Shore Shunt

Science.gov (United States)

Krabbenhoft, D. P.; DeWild, J. F.; Maglio, M. M.; Tate, M. T.; Ogorek, J. M.; Hurley, J. P.; Lepak, R.

2013-12-01

Mercury (Hg) contamination of the aquatic food webs across the Great Lakes remains a significant environmental issue. However, our ability to prescribe corrective actions has been significantly hampered by a scarcity of data, particularly for methylmercury (MeHg) the most toxic and bioaccumulative form of mercury in freshwater ecosystems. As part of the Great Lakes Restoration Initiative initiated in 2010, a joint effort was undertaken by the U.S. Geological Survey (USGS) and U.S. Environmental Protection Agency (USEPA) to improve our understanding of total Hg and MeHg concentrations and distributions in the Great Lakes. Since 2010, sampling surveys have been conducted at about 15-20 stations twice annually (April and August) at 15-20 stations per lake to collect data from both cold and warm water conditions. All sampling was conducted using trace-metal free protocols using a sampling rosette equipped with 12 Teflon-lined Niskin. Water samples were collected at predetermined depths: mid-epilimnion, mid-thermocline, deep chlorophyll layer, mid-hypolimnion, and about 2 meters above the bottom. Seston samples were collected from the top 20 meters using plankton nets, while bottom sediments and benthos samples were acquired using a ponar sampler. Water, biota, and sediment samples were all analyzed for Hg and MeHg concentration at the USGS Mercury Research Laboratory in Middleton, Wisconsin. Several important trends are apparent from the water column samples. First, most stations reveal a strong top-to-bottom declining trend total Hg concentration, underscoring the importance of atmospheric deposition to the Great Lakes. Methylmercury profiles, show maximal concentrations at the thermocline or deep chlorophyll layer, suggesting in situ water-column MeHg production. Calculations suggest this in-lake MeHg source is similar in magnitude to tributary loading of MeHg, which heretofore was thought to be the dominant MeHg source. Aqueous total Hg results also suggest that

Contaminants of emerging concern in tributaries to the Laurentian Great Lakes: I. Patterns of occurrence

Science.gov (United States)

Elliott, Sarah M.; Brigham, Mark E.; Lee, Kathy E.; Banda, Jo A.; Choy, Steven J.; Gefell, Daniel J.; Minarik, Thomas A.; Moore, Jeremy N.; Jorgenson, Zachary G.

2017-01-01

Human activities introduce a variety of chemicals to the Laurentian Great Lakes including pesticides, pharmaceuticals, flame retardants, plasticizers, and solvents (collectively referred to as contaminants of emerging concern or CECs) potentially threatening the vitality of these valuable ecosystems. We conducted a basin-wide study to identify the presence of CECs and other chemicals of interest in 12 U.S. tributaries to the Laurentian Great Lakes during 2013 and 2014. A total of 292 surface-water and 80 sediment samples were collected and analyzed for approximately 200 chemicals. A total of 32 and 28 chemicals were detected in at least 30% of water and sediment samples, respectively. Concentrations ranged from 0.0284 (indole) to 72.2 (cholesterol) μg/L in water and 1.75 (diphenhydramine) to 20,800 μg/kg (fluoranthene) in sediment. Cluster analyses revealed chemicals that frequently co-occurred such as pharmaceuticals and flame retardants at sites receiving similar inputs such as wastewater treatment plant effluent. Comparison of environmental concentrations to water and sediment-quality benchmarks revealed that polycyclic aromatic hydrocarbon concentrations often exceeded benchmarks in both water and sediment. Additionally, bis(2-ethylhexyl) phthalate and dichlorvos concentrations exceeded water-quality benchmarks in several rivers. Results from this study can be used to understand organism exposure, prioritize river basins for future management efforts, and guide detailed assessments of factors influencing transport and fate of CECs in the Great Lakes Basin.

Short-Term Bluff Recession Behavior Along Pennsylvania's Great Lakes Coastline, USA

Science.gov (United States)

Foyle, A. M.; Naber, M. D.; Pluta, M. J.

2011-12-01

Coastal bluff retreat is a common problem along the world's unconsolidated coastlines. On the Great Lakes coast of Pennsylvania, Quaternary clay-rich glacial till, paleo-lake plain, and sandy strandplain sequences overlie Devonian bedrock. These Quaternary strata are subject to subaerial and lacustrine erosional processes that cause permanent coastal land loss at spatially variable rates, with the former (runoff, slumping, groundwater focusing, etc) dominating over the latter (wave and current scour, abrasion, etc). Land loss is of concern to environmental agencies because land-use planning should account for spatial and temporal variability in land-loss rates, and because bluff erosion contributes to a temporary degradation in coastal water quality. The goal of this study is to evaluate spatial variability in bluff retreat rates along a 20 km sector of Pennsylvania's short Great Lakes coast. High resolution LiDAR data covering a one-decade time frame (1998-2007) permit bluff-crest mapping on two comparable data sets that captures change within a timeframe similar to CZM planning intervals. Short-term recession data can be more useful, cost-effective, and accurate than long-term analyses that use lower-resolution field measurements, T-sheets, and historical aerial photography. Bluffs along the 20 km coastal study site consist of up to 26 m of unlithified Quaternary sediments overlying a 1-4 m ledge of sub-horizontal Devonian shale and sandstone. Bluff slopes range from 20-90 degrees, beaches are narrow (wide) or absent, and the bluffs are seasonally shielded by ground-freeze and lake ice. DEMs, hillshades, and slope and contour maps were generated from bare-earth 1998 and 2007 LiDAR data, and checked against 2005 aerial ortho-photography. Maps were analyzed at a scale of 1:120 in ArcGIS and the bluff crest was identified primarily by the visual-break-in-slope method. Rates of bluff retreat derived using DSAS vary from unresolvable to as much as 2.2 m/yr, averaging

MACROPHYTE RICHNESS AND AQUATIC VEGETATION COMPLEXITY OF THE LAKE IDRO (NORTHERN ITALY

Directory of Open Access Journals (Sweden)

R. Bolpagni

2013-04-01

Full Text Available A detailed survey was performed to examine the floristic richness and the structural complexity, spatial patterns and conservation value of aquatic plant communities within the littorals of Lake Idro (northern Italy. During the summers of 2010-2011 we proceeded to characterize aquatic macrophyte meadows applying standardized procedures using transects (44 and plots (49 arrayed perpendicular to the shoreline and randomly positioned within the vegetated belt, respectively. Lake Idro is characterized by rather high floristic richness (20 macrophytes but low levels of vegetation structural complexity (8 vegetation units. Nevertheless, a clear zonation of the littoral vegetation was identified with two main macro-layers: a deeper layer (between 6-10 m of depth dominated by Chara globularis and an upper one (from 6 m of depth to water-air atmosphere mainly colonized by alien elodeids (mainly Elodea nuttallii and Lagarosiphon major. For the first time a complete floristic-vegetation analysis of the Lake Idro was presented. Our data confirm the poor ecological status of the basin, even though the lacustrine vegetation can be considered of conservation concern. Further investigations are needed to improve present evaluations, especially with respect to the impact of eutrophication on macrophytic communities.

Climatic and pollution influences on ecosystem processes in northern hardwood forests

Science.gov (United States)

Kurt S. Pregitzer; David D. Reed; Glenn D. Mroz; Andrew J. Burton; John A. Witter; Donald A. Zak

1996-01-01

The Michigan gradient study was established in 1987 to examine the effects of climate and atmospheric deposition on forest productivity and ecosystem processes in the Great Lakes region. Four intensively-monitored northern hardwood study sites are located along a climatic and pollutant gradient extending from southern lower Michigan to northwestern upper Michigan. The...

Lake Afdera: a threatened saline lake in Ethiopia | Getahun | SINET ...

African Journals Online (AJOL)

Lake Afdera is a saline lake located in the Afar region, Northern Ethiopia. Because of its inaccessibility it is one of the least studied lakes of the country. It supports life including three species of fish of which two are endemic. Recently, reports are coming out that this lake is used for salt extraction. This paper gives some ...

Post-glacial recolonization of the Great Lakes region by the common gartersnake (Thamnophis sirtalis) inferred from mtDNA sequences.

Science.gov (United States)

Placyk, John S; Burghardt, Gordon M; Small, Randall L; King, Richard B; Casper, Gary S; Robinson, Jace W

2007-05-01

Pleistocene events played an important role in the differentiation of North American vertebrate populations. Michigan, in particular, and the Great Lakes region, in general, were greatly influenced by the last glaciation. While several hypotheses regarding the recolonization of this region have been advanced, none have been strongly supported. We generated 148 complete ND2 mitochondrial DNA (mtDNA) sequences from common gartersnake (Thamnophis sirtalis) populations throughout the Great Lakes region to evaluate phylogeographic patterns and population structure and to determine whether the distribution of haplotypic variants is related to the post-Pleistocene retreat of the Wisconsinan glacier. The common gartersnake was utilized, as it is believed to have been one of the primary vertebrate invaders of the Great Lakes region following the most recent period of glacial retreat and because it has been a model species for a variety of evolutionary, ecological, behavioral, and physiological studies. Several genetically distinct evolutionary lineages were supported by both genealogical and molecular population genetic analyses, although to different degrees. The geographic distribution of the majority of these lineages is interpreted as reflecting post-glacial recolonization dynamics during the late Pleistocene. These findings generally support previous hypotheses of range expansion in this region.

First evidence of grass carp recruitment in the Great Lakes Basin

Science.gov (United States)

Chapman, Duane C.; Davis, J. Jeremiah; Jenkins, Jill A.; Kocovsky, Patrick M.; Miner, Jeffrey G.; Farver, John; Jackson, P. Ryan

2013-01-01

We use aging techniques, ploidy analysis, and otolith microchemistry to assess whether four grass carp Ctenopharyngodon idella captured from the Sandusky River, Ohio were the result of natural reproduction within the Lake Erie Basin. All four fish were of age 1 +. Multiple lines of evidence indicate that these fish were not aquaculture-reared and that they were most likely the result of successful reproduction in the Sandusky River. First, at least two of the fish were diploid; diploid grass carp cannot legally be released in the Great Lakes Basin. Second, strontium:calcium (Sr:Ca) ratios were elevated in all four grass carp from the Sandusky River, with elevated Sr:Ca ratios throughout the otolith transect, compared to grass carp from Missouri and Arkansas ponds. This reflects the high Sr:Ca ratio of the Sandusky River, and indicates that these fish lived in a high-strontium environment throughout their entire lives. Third, Sandusky River fish were higher in Sr:Ca ratio variability than fish from ponds, reflecting the high but spatially and temporally variable strontium concentrations of southwestern Lake Erie tributaries, and not the stable environment of pond aquaculture. Fourth, Sr:Ca ratios in the grass carp from the Sandusky River were lower in their 2011 growth increment (a high water year) than the 2012 growth increment (a low water year), reflecting the observed inverse relationship between discharge and strontium concentration in these rivers. We conclude that these four grass carp captured from the Sandusky River are most likely the result of natural reproduction within the Lake Erie Basin.

Forecasting effects of climate change on Great Lakes fisheries: models that link habitat supply to population dynamics can help

Science.gov (United States)

Jones, Michael L.; Shuter, Brian J.; Zhao, Yingming; Stockwell, Jason D.

2006-01-01

Future changes to climate in the Great Lakes may have important consequences for fisheries. Evidence suggests that Great Lakes air and water temperatures have risen and the duration of ice cover has lessened during the past century. Global circulation models (GCMs) suggest future warming and increases in precipitation in the region. We present new evidence that water temperatures have risen in Lake Erie, particularly during summer and winter in the period 1965–2000. GCM forecasts coupled with physical models suggest lower annual runoff, less ice cover, and lower lake levels in the future, but the certainty of these forecasts is low. Assessment of the likely effects of climate change on fish stocks will require an integrative approach that considers several components of habitat rather than water temperature alone. We recommend using mechanistic models that couple habitat conditions to population demographics to explore integrated effects of climate-caused habitat change and illustrate this approach with a model for Lake Erie walleye (Sander vitreum). We show that the combined effect on walleye populations of plausible changes in temperature, river hydrology, lake levels, and light penetration can be quite different from that which would be expected based on consideration of only a single factor.

Spatial variations in water composition at a northern Canadian lake impacted by mine drainage

International Nuclear Information System (INIS)

Moncur, M.C.; Ptacek, C.J.; Blowes, D.W.; Jambor, J.L.

2006-01-01

Release of acid drainage from mine-waste disposal areas is a problem of international scale. Contaminated surface water, derived from mine wastes, originates both as direct surface runoff and, indirectly, as subsurface groundwater flow. At Camp Lake, a small Canadian Shield lake that is in northern Manitoba and is ice-covered 6 months of the year, direct and indirect release of drainage from an adjacent sulfide-rich tailings impoundment has severely affected the quality of the lake water. Concentrations of the products from sulfide oxidation are extremely high in the pore waters of the tailings impoundment. Groundwater and surface water derived from the impoundment discharge into a semi-isolated shallow bay in Camp Lake. The incorporation of this aqueous effluent has altered the composition of the lake water, which in turn has modified the physical limnology of the lake. Geochemical profiles of the water column indicate that, despite its shallow depth (6 m), the bay is stratified throughout the year. The greatest accumulation of dissolved metals and SO 4 is in the lower portion of the water column, with concentrations up to 8500 mg L -1 Fe, 20,000 mg L -1 SO 4 , 30 mg L -1 Zn, 100 mg L -1 Al, and elevated concentrations of Cu, Cd, Pb and Ni. Meromictic conditions and very high solute concentrations are limited to the bay. Outside the bay, solute concentrations are lower and some stratification of the water column exists. Identification of locations and composition of groundwater discharge relative to lake bathymetry is a fundamental aspect of understanding chemical evolution and physical stability of mine-impacted lakes

Peat accumulation in drained thermokarst lake basins in continuous, ice-rich permafrost, northern Seward Peninsula, Alaska

Science.gov (United States)

Jones, Miriam C.; Grosse, Guido; Jones, Benjamin M.; Anthony, Katey Walter

2012-01-01

Thermokarst lakes and peat-accumulating drained lake basins cover a substantial portion of Arctic lowland landscapes, yet the role of thermokarst lake drainage and ensuing peat formation in landscape-scale carbon (C) budgets remains understudied. Here we use measurements of terrestrial peat thickness, bulk density, organic matter content, and basal radiocarbon age from permafrost cores, soil pits, and exposures in vegetated, drained lake basins to characterize regional lake drainage chronology, C accumulation rates, and the role of thermokarst-lake cycling in carbon dynamics throughout the Holocene on the northern Seward Peninsula, Alaska. Most detectable lake drainage events occurred within the last 4,000 years with the highest drainage frequency during the medieval climate anomaly. Peat accumulation rates were highest in young (50–500 years) drained lake basins (35.2 g C m−2 yr−1) and decreased exponentially with time since drainage to 9 g C m−2 yr−1 in the oldest basins. Spatial analyses of terrestrial peat depth, basal peat radiocarbon ages, basin geomorphology, and satellite-derived land surface properties (Normalized Difference Vegetation Index (NDVI); Minimum Noise Fraction (MNF)) from Landsat satellite data revealed significant relationships between peat thickness and mean basin NDVI or MNF. By upscaling observed relationships, we infer that drained thermokarst lake basins, covering 391 km2 (76%) of the 515 km2 study region, store 6.4–6.6 Tg organic C in drained lake basin terrestrial peat. Peat accumulation in drained lake basins likely serves to offset greenhouse gas release from thermokarst-impacted landscapes and should be incorporated in landscape-scale C budgets.

Money, management, and manipulation: Environmental mobilization in the Great Lakes basin

International Nuclear Information System (INIS)

Gould, K.A.

1991-01-01

This document examines variations in the responses of communities to local pollution problems affecting Great Lakes water quality. The study is based on research conducted at six such communities, at sites that have been designated as 'Areas of Concern' by the International Joint Commission. The roles of economic dependency or diversity, access to scientific and political resources, community size, social visibility of pollution, and consciousness- and unconsciousness-making activities are examined as they relate to grass roots political mobilization in response to local, lake-related environmental issues. Of particular interest is the participation of national and regional environmental social movement organizations, Federal, State/Provincial and local governments, and local industry. National and regional environmental social movement organizations appear to have a greater mobilizing impact on communities that are closest to the urban centers in which these organizations are based. State and Provincial environmental agencies play a centrist role in promoting minimal remediation. Local governments typically oppose the definition of local environmental disorganization as a problem

Microplastic pollution in the surface waters of the Laurentian Great Lakes.

Science.gov (United States)

Eriksen, Marcus; Mason, Sherri; Wilson, Stiv; Box, Carolyn; Zellers, Ann; Edwards, William; Farley, Hannah; Amato, Stephen

2013-12-15

Neuston samples were collected at 21 stations during an ~700 nautical mile (~1300 km) expedition in July 2012 in the Laurentian Great Lakes of the United States using a 333 μm mesh manta trawl and analyzed for plastic debris. Although the average abundance was approximately 43,000 microplastic particles/km², station 20, downstream from two major cities, contained over 466,000 particles/km², greater than all other stations combined. SEM analysis determined nearly 20% of particles less than 1 mm, which were initially identified as microplastic by visual observation, were aluminum silicate from coal ash. Many microplastic particles were multi-colored spheres, which were compared to, and are suspected to be, microbeads from consumer products containing microplastic particles of similar size, shape, texture and composition. The presence of microplastics and coal ash in these surface samples, which were most abundant where lake currents converge, are likely from nearby urban effluent and coal burning power plants.

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.

Grass carp in the Great Lakes region: establishment potential, expert perceptions, and re-evaluation of experimental evidence of ecological impact

Science.gov (United States)

Wittmann, Marion E.; Jerde, Christopher L.; Howeth, Jennifer G.; Maher, Sean P.; Deines, Andrew M.; Jenkins, Jill A.; Whitledge, Gregory W.; Burbank, Sarah B.; Chadderton, William L.; Mahon, Andrew R.; Tyson, Jeffrey T.; Gantz, Crysta A.; Keller, Reuben P.; Drake, John M.; Lodge, David M.

2014-01-01

Intentional introductions of nonindigenous fishes are increasing globally. While benefits of these introductions are easily quantified, assessments to understand the negative impacts to ecosystems are often difficult, incomplete, or absent. Grass carp (Ctenopharyngodon idella) was originally introduced to the United States as a biocontrol agent, and recent observations of wild, diploid individuals in the Great Lakes basin have spurred interest in re-evaluating its ecological risk. Here, we evaluate the ecological impact of grass carp using expert opinion and a suite of the most up-to-date analytical tools and data (ploidy assessment, eDNA surveillance, species distribution models (SDMs), and meta-analysis). The perceived ecological impact of grass carp by fisheries experts was variable, ranging from unknown to very high. Wild-caught triploid and diploid individuals occurred in multiple Great Lakes waterways, and eDNA surveillance suggests that grass carp are abundant in a major tributary of Lake Michigan. SDMs predicted suitable grass carp climate occurs in all Great Lakes. Meta-analysis showed that grass carp introductions impact both water quality and biota. Novel findings based on updated ecological impact assessment tools indicate that iterative risk assessment of introduced fishes may be warranted.

Regulations and policies that limit the growth of the U.S. Great Lakes cruising market.

Science.gov (United States)

2011-10-01

The worldwide cruise industry has seen remarkable growth since the 1990s. The cruise market on the Great Lakes has lagged the worldwide growth and compared to historical records, has fallen far short of its full potential. This paper reviews the hist...

EXTRACELLULAR ENZYME ACTIIVTY AS A SURROGATE FOR NUTRIENTS AND NUTRIENT HISTORY IN GREAT LAKES WETLANDS

Science.gov (United States)

Great Lakes ecosystems are generally thought to be P-limited, but N-limitation may be more common than previously suspected. N-limitation should be most obvious in freshwater coastal wetlands, where the anaerobic oxidation of organic carbon may be limited by nitrate availability...

Assessment of a new seasonal to inter-annual operational Great Lakes water supply, water levels, and connecting channel flow forecasting system

Science.gov (United States)

Gronewold, A.; Fry, L. M.; Hunter, T.; Pei, L.; Smith, J.; Lucier, H.; Mueller, R.

2017-12-01

The U.S. Army Corps of Engineers (USACE) has recently operationalized a suite of ensemble forecasts of Net Basin Supply (NBS), water levels, and connecting channel flows that was developed through a collaboration among USACE, NOAA's Great Lakes Environmental Research Laboratory, Ontario Power Generation (OPG), New York Power Authority (NYPA), and the Niagara River Control Center (NRCC). These forecasts are meant to provide reliable projections of potential extremes in daily discharge in the Niagara and St. Lawrence Rivers over a long time horizon (5 years). The suite of forecasts includes eight configurations that vary by (a) NBS model configuration, (b) meteorological forcings, and (c) incorporation of seasonal climate projections through the use of weighting. Forecasts are updated on a weekly basis, and represent the first operational forecasts of Great Lakes water levels and flows that span daily to inter-annual horizons and employ realistic regulation logic and lake-to-lake routing. We will present results from a hindcast assessment conducted during the transition from research to operation, as well as early indications of success rates determined through operational verification of forecasts. Assessment will include an exploration of the relative skill of various forecast configurations at different time horizons and the potential for application to hydropower decision making and Great Lakes water management.

Climate Change Impacts on Nutrient Losses of Two Watersheds in the Great Lakes Region

Directory of Open Access Journals (Sweden)

Lili Wang

2018-04-01

Full Text Available Non-point sources (NPS of agricultural chemical pollution are one major reason for the water quality degradation of the Great Lakes, which impacts millions of residents in the states and provinces that are bordering them. Future climate change will further impact water quality in both direct and indirect ways by influencing the hydrological cycle and processes of nutrient transportation and transformation, but studies are still rare. This study focuses on quantifying the impacts of climate change on nutrient (Nitrogen and Phosphorus losses from the two small watersheds (Walworth watershed and Green Lake watershed within the Great Lakes region. Analysis focused on changes through this century (comparing the nutrient loss prediction of three future periods from 2015 to 2099 with 30 years for each period against the historical nutrient estimation data from 1985 to 2008. The effects on total phosphorus and nitrate-nitrogen losses due to changes in precipitation quantity, intensity, and frequency, as well as air temperature, are evaluated for the two small watersheds, under three special report emission scenarios (SRES A2, A1B, B1. The newly developed Water Erosion Prediction Project-Water Quality (WEPP-WQ model is utilized to simulate nutrient losses with downscaled and bias corrected future climate forcing from two General Circulation Models (GFDL, HadCM3. For each watershed, the observed runoff and nutrient loads are used to calibrate and validate the model before the application of the WEPP-WQ model to examine potential impacts from future climate change. Total phosphorus loss is projected to increase by 28% to 89% for the Green Lake watershed and 25% to 108% for the Walworth watershed mainly due to the combined effects of increase of precipitation quantity, extreme storm events in intensity and frequency, and air temperature. Nitrate-nitrogen losses are projected to increase by 1.1% to 38% for the Green Lake watershed and 8% to 95% for the

Materials for Public Listening Session - Stakeholder Input on Public Notice for CSOs in the Great Lakes

Science.gov (United States)

Materials for the Public Listening Session on September 14, 2016, to obtain information from the public to help inform development of a new regulation establishing requirements for public notification of CSO discharges in the Great Lakes.

Mid-latitude Ozone Depletion Events Caused by Halogens from the Great Salt Lake in Utah

Science.gov (United States)

Fibiger, D. L.; Goldberger, L.; Womack, C.; McDuffie, E. E.; Dube, W. P.; Franchin, A.; Middlebrook, A. M.; Thornton, J. A.; Brown, S. S.

2017-12-01

Halogens are highly reactive chemicals and play an important role in atmospheric chemistry. They can be involved in many cycles which influence the oxidizing capacity of the atmosphere, including through destruction of ozone (O3). While the influence of halogens on O3 is well documented in the arctic, there are very few observations of O3 depletion driven by halogens in the mid-latitudes. To date, the most comprehensive study observed co-occurring plumes of BrO and depleted O3 near the Dead Sea in 1997. During the Utah Wintertime Fine Particulate Study (UWFPS) in winter 2017, simultaneous measurements of a comprehensive suite of halogen measurements by I- chemical ionization mass spectrometry and O3 from cavity ring-down spectroscopy, both at 1-second time resolution, were taken on a NOAA Twin Otter Aircraft over the Great Salt Lake and in the surrounding valleys. Many O3 depletion events were observed over the lake with O3 values sometimes below the instrument detection limit of 0.5 ppbv. Corresponding increases in BrO and/or ClO were observed. Many of these events were caused by extremely high levels of halogens (up to 1 ppmv Cl2) emitted from the U.S. Magnesium plant on the edge of the lake. The O3 depletion caused by U.S. Magnesium was usually isolated to a distinct vertical layer, but in other cases O3 depletion was vertically mixed and the origin of halogen activation was not immediately clear. The most complete O3 depletion was observed over the lake, but there were smaller events of a few ppbv observed in the adjacent valleys, including the highly populated Salt Lake Valley, with corresponding plumes of BrO and ClO, due to transport from the lake. Additionally, meteorology played a role in the observed O3 depletion. The strongest O3 depletion was observed during inversion events, when there is a low boundary layer and little mixing out of the air above the lake. During non-inversion conditions, only small depletions were observed, covering a much smaller

Ballast Water Treatment, U.S. Great Lakes Bulk Carrier Engineering and Cost Study. Volume 1: Present Conditions

Science.gov (United States)

2013-11-01

There are two U.S. cement plants (Charlevoix and Alpena ) that supply all U.S. ports on the lakes. Ballast Water Treatment, U.S. Great Lakes...Marquette, MI Brevort, MI Buffington, IN Alpena , MI Bay City, MI Cleveland, OH Ashtabula, OH Duluth, MN Munising, MI Charlevoix, MI Burns Harbor, IN...Manitowoc Pathfinder Calumet Alpena Total shown: 40,699,415 mt Total, all U.S. Vsls: 42,508,108 mt % ballast moved by top 5 vsls

Chernobyl accident. The radioactive contamination in the area of Lake Como and in other Northern Italy sites

Energy Technology Data Exchange (ETDEWEB)

Capra, D.; Facchini, U.; Gianelle, V.; Ravasini, G.; Ravera, O.; Pizzala, A.; Bacci, P.

The radioactive cloud released during the Chernobyl accident reached the Po Plain and Lombardy in the night of April 30, 1986; the cloud remained in the Northern Italian skies for a few days and then disappeared either dispersed by winds or washed by rains. The evidence in the atmosphere of radionuclides as tellurium, iodine, cesium was promply observed by the Istituto di Fisica. The intense rain, in the first week of May, washed the radioactivity and the fallout contaminated the land, soil, grass and vegetables. The present work concerns the overall contamination of the Northern Italy territory and in particular the radioactive fallout in the Alpine region. Samples of soil have been measured at the gamma-spectroscope; a linear correlation is found between the radionuclide concentration in soil samples and the rain intensity, when appropriate deposition models are considered. A number of measurements has been done on Lake Como ecosystem: sediments, plankton, fishes and the overall fallout in the lake area have been investigated.

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

Science.gov (United States)

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

2018-01-01

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

Cosmogenic 10Be Dating of Northern Quebec-Labrador Glacial Lake Shorelines and Drainage Deposits: Implications for the Final Meltwater Discharges of the Last Deglaciation

Science.gov (United States)

Roy, M.; Dube-Loubert, H.; Schaefer, J. M.; Hébert, S.

2017-12-01

The decay of the Laurentide ice sheet played an important role in the climate variability of the last deglaciation, notably through large discharges of meltwater from glacial lakes that disturbed the Atlantic meridional overturning oceanic circulation (AMOC). These former climate-forcing events are now under focus due to growing evidence showing that the present-day increase in freshwater releases from Greenland and other Arctic glaciers may potentially lead to a slowdown of the AMOC and cause important climate feedbacks. In northern Quebec and Labrador, the end of the deglaciation led to the formation of at least 10 important glacial lakes that drained into the nearby Labrador Sea where repeated meltwater discharges could have destabilized the ocean surface conditions in this key sector of the North Atlantic Ocean. Although the drainage of these ice-dammed lakes may form a good analogue for modern processes, the lack of direct constraints on the physiographic configuration and temporal evolution of these lakes limits our understanding of the timing and climate impact of these final meltwater pulses. Here we applied cosmogenic 10Be dating to raised boulder shorelines belonging to Lake Naskaupi, one of the largest glacial lakes in northern Quebec and Labrador. We reconstructed the lake extent and meltwater volume, as well as its lake-level history by systematic mapping of geomorphic features. We sampled a total of 16 boulders at 4 sites along the valley. In addition, we dated five boulders belonging to a large-scale outburst flood deposit recording the abrupt drainage of the lake. The distribution of the 21 ages shows a remarkable consistency, yielding a mean age of 7.8 ± 0.4 ka (1 outlier excluded). The ages from the shorelines are indistinguishable from those of the outburst flood deposit, suggesting that Lake Naskaupi existed for a relatively short time span. These new chronological data constrain the timing of the lake development and attendant drainage

75 FR 82141 - Stakeholder Meetings Regarding the U.S.-Flag Great Lakes Fleet Revitalization Study

Science.gov (United States)

2010-12-29

... future role of Great Lakes shipping in supporting the region's economy and as an important component of... port assets will be developed. That inventory will be used to determine if the Maritime Administration... environmental regulations. This analysis will be used in developing strategies for how the Maritime...

Mapping Cropland and Major Crop Types Across the Great Lakes Basin Using MODIS-NDVI Data

Science.gov (United States)

This research evaluated the potential for using the MODIS Normalized Difference Vegetation Index (NDVI) 16-day composite (MOD13Q) 250-m time-series data to develop a cropland mapping capability throughout the 480 000 km2 Great Lakes Basin (GLB). Cropland mapping was conducted usi...

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.

Glial cell biology in the Great Lakes region.

Science.gov (United States)

Feinstein, Douglas L; Skoff, Robert P

2016-03-31

We report on the tenth bi-annual Great Lakes Glial meeting, held in Traverse City, Michigan, USA, September 27-29 2015. The GLG meeting is a small conference that focuses on current research in glial cell biology. The array of functions that glial cells (astrocytes, microglia, oligodendrocytes, Schwann cells) play in health and disease is constantly increasing. Despite this diversity, GLG meetings bring together scientists with common interests, leading to a better understanding of these cells. This year's meeting included two keynote speakers who presented talks on the regulation of CNS myelination and the consequences of stress on Schwann cell biology. Twenty-two other talks were presented along with two poster sessions. Sessions covered recent findings in the areas of microglial and astrocyte activation; age-dependent changes to glial cells, Schwann cell development and pathology, and the role of stem cells in glioma and neural regeneration.

Development of a GIS interface for WEPP Model application to Great Lakes forested watersheds

Science.gov (United States)

J. R. Frankenberger; S. Dun; D. C. Flanagan; J. Q. Wu; W. J. Elliot

2011-01-01

This presentation will highlight efforts on development of a new online WEPP GIS interface, targeted toward application in forested regions bordering the Great Lakes. The key components and algorithms of the online GIS system will be outlined. The general procedures used to provide input to the WEPP model and to display model output will be demonstrated.

Invasive fish species in the largest lakes of Scotland, Northern Ireland, Wales and England: the collective U.K. experience

OpenAIRE

Winfield, I.J.; Fletcher, J.M.; James, J.B.

2011-01-01

An invasive species is defined as an alien (or introduced or non-native) species whose establishment and spread threaten ecosystems, habitats or species with harm. Such threats to UK lake fish communities have long been appreciated and this review assembles case histories, including new data, from the largest lakes of Scotland, Northern Ireland, Wales and England to examine the hypothesis that at least some of these introductions have become invasive. Loch Lomond in Scotland has experienced s...

Analysis of fish movements between Great Lakes coastal wetlands and near shore habitat via otolith microchemistry

Science.gov (United States)

Great Lakes coastal wetlands are unique habitats with physical connections with near shore environments. This facilitates the exchange of energy between habitats in a principle known as habitat coupling. Coupling can be facilitated by movements of consumers; however, wetland us...

76 FR 1665 - Stakeholder Meetings Regarding the U.S.-Flag Great Lakes Fleet Revitalization Study; Correction

Science.gov (United States)

2011-01-11

... DEPARTMENT OF TRANSPORTATION Maritime Administration [Docket No. MARAD-2010-0111] Stakeholder Meetings Regarding the U.S.-Flag Great Lakes Fleet Revitalization Study; Correction AGENCY: Maritime Administration, Department of Transportation. ACTION: Correction Notice. SUMMARY: On December 29, 2010, at 75 FR...

Evaluation of a rural demonstration program to increase seat belt use in the Great Lakes Region.

Science.gov (United States)

2009-03-01

Six States in the Great Lakes Region (Region 5) participated in a Rural Demonstration Program to increase seat belt : use in rural areas and among high-risk occupants, such as young males and occupants of pickup trucks. These : efforts, which include...

Low-dose glyphosate does not control annual bromes in the northern Great Plains

Science.gov (United States)

Annual bromes (downy brome and Japanese brome) have been shown to decrease perennial grass forage production and alter ecosystem functions in northern Great Plains rangelands. Large-scale chemical control might be a method for increasing rangeland forage production if low application rates confer co...

Measurement and Analysis of Extreme Wave and Ice Actions in the Great Lakes for Offshore Wind Platform Design

Energy Technology Data Exchange (ETDEWEB)

England, Tony [Univ. of Michigan, Ann Arbor, MI (United States). College of Engineering; van Nieuwstadt, Lin [Univ. of Michigan, Ann Arbor, MI (United States). College of Engineering; De Roo, Roger [Univ. of Michigan, Ann Arbor, MI (United States). College of Engineering; Karr, Dale [Univ. of Michigan, Ann Arbor, MI (United States). College of Engineering; Lozenge, David [Univ. of Michigan, Ann Arbor, MI (United States). College of Engineering; Meadows, Guy [Univ. of Michigan, Ann Arbor, MI (United States). College of Engineering

2016-05-30

This project, funded by the Department of Energy as DE-EE0005376, successfully measured wind-driven lake ice forces on an offshore structure in Lake Superior through one of the coldest winters in recent history. While offshore regions of the Great Lakes offer promising opportunities for harvesting wind energy, these massive bodies of freshwater also offer extreme and unique challenges. Among these challenges is the need to anticipate forces exerted on offshore structures by lake ice. The parameters of interest include the frequency, extent, and movement of lake ice, parameters that are routinely monitored via satellite, and ice thickness, a parameter that has been monitored at discrete locations over many years and is routinely modeled. Essential relationships for these data to be of use in the design of offshore structures and the primary objective of this project are measurements of maximum forces that lake ice of known thicknesses might exert on an offshore structure.

New records of the rare glacial relict Eurytemora lacustris (Poppe 1887 (Copepoda; Calanoida in atypical lake habitats of northern Germany

Directory of Open Access Journals (Sweden)

Peter KASPRZAK

2011-02-01

Full Text Available During monitoring investigations of lakes in Schleswig-Holstein (northern Germany in 2000 and 2008, the calanoid copepod Eurytemora lacustris (POPPE 1887 was found in three lakes of the Ratzeburger Lake complex: the Kleine Küchensee, the Große Küchensee and the Große Ratzeburger See. The species has a broad geographic distribution but has become rare and endangered by eutrophication and global change. The lakes are mesotrophic (Gr. Ratzeburger See and eutrophic (Kl. Küchensee, Gr. Küchensee with cool (1 mg O2 L-1. Food and physical conditions seem to be favourable enough to permit survival and reproduction of the species at least in spring. It remains unclear, however, whether the populations in the studied lakes are autochthonous. Eurytemora lacustris possibly invaded the lakes or was transported via a canal from the Schaalsee upstream, where a viable population exists.

Post-War Economics. Micro-Level Evidence from the African Great Lakes Region

OpenAIRE

D'Aoust, Olivia

2015-01-01

This thesis starts by arguing that the civil conflicts that erupted in the African Great Lakes are rooted in a continuous pursuit of power, in which ethnic, regional and political identifiers are used by the contenders for power to rally community support. In an introductory chapter, I go back to the colonial era, drawing attention to Burundi and Rwanda, and then describe in more details Burundi's refugee crisis, ex-combatants' demobilization and the 2010 elections, all of which will be addre...

Bathymetry of Lake Erie and Lake Saint Clair

Data.gov (United States)

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

The spatial scale for cisco recruitment dynamics in Lake Superior during 1978-2007

Science.gov (United States)

Rook, Benjamin J.; Hansen, Michael J.; Gorman, Owen T.

2012-01-01

The cisco Coregonus artedi was once the most abundant fish species in the Great Lakes, but currently cisco populations are greatly reduced and management agencies are attempting to restore the species throughout the basin. To increase understanding of the spatial scale at which density‐independent and density‐dependent factors influence cisco recruitment dynamics in the Great Lakes, we used a Ricker stock–recruitment model to identify and quantify the appropriate spatial scale for modeling age‐1 cisco recruitment dynamics in Lake Superior. We found that the recruitment variation of ciscoes in Lake Superior was best described by a five‐parameter regional model with separate stock–recruitment relationships for the western, southern, eastern, and northern regions. The spatial scale for modeling was about 260 km (range = 230–290 km). We also found that the density‐independent recruitment rate and the rate of compensatory density dependence varied among regions at different rates. The density‐independent recruitment rate was constant among regions (3.6 age‐1 recruits/spawner), whereas the rate of compensatory density dependence varied 16‐fold among regions (range = −0.2 to −2.9/spawner). Finally, we found that peak recruitment and the spawning stock size that produced peak recruitment varied among regions. Both peak recruitment (0.5–7.1 age‐1 recruits/ha) and the spawning stock size that produced peak recruitment (0.3–5.3 spawners/ha) varied 16‐fold among regions. Our findings support the hypothesis that the factors driving cisco recruitment operate within four different regions of Lake Superior, suggest that large‐scale abiotic factors are more important than small‐scale biotic factors in influencing cisco recruitment, and suggest that fishery managers throughout Lake Superior and the entire Great Lakes basin should address cisco restoration and management efforts on a regional scale in each lake.

Evaluation of an operational water cycle prediction system for the Laurentian Great Lakes and St. Lawrence River

Science.gov (United States)

Fortin, Vincent; Durnford, Dorothy; Smith, Gregory; Dyck, Sarah; Martinez, Yosvany; Mackay, Murray; Winter, Barbara

2017-04-01

Environment and Climate Change Canada (ECCC) is implementing new numerical guidance products based on fully coupled numerical models to better inform the public as well as specialized users on the current and future state of various components of the water cycle, including stream flow and water levels. Outputs from this new system, named the Water Cycle Prediction System (WCPS), have been available for the Great Lakes and St. Lawrence River watershed since June 2016. WCPS links together ECCC's weather forecasting model, GEM, the 2-D ice model C-ICE, the 3-D lake and ocean model NEMO, and a 2-D hydrological model, WATROUTE. Information concerning the water cycle is passed between the models at intervals varying from a few minutes to one hour. It currently produces two forecasts per day for the next three days of the complete water cycle in the Great Lakes region, the largest freshwater lake system in the world. Products include spatially-varying precipitation, evaporation, river discharge, water level anomalies, surface water temperatures, ice coverage, and surface currents. These new products are of interest to water resources and management authority, flood forecasters, hydroelectricity producers, navigation, environmental disaster managers, search and rescue teams, agriculture, and the general public. This presentation focuses on the evaluation of various elements forecasted by the system, and weighs the advantages and disadvantages of running the system fully coupled.

Sea lamprey (Petromyzon marinus) parasite-host interactions in the Great Lakes

Science.gov (United States)

Bence, James R.; Bergstedt, Roger A.; Christie, Gavin C.; Cochran, Phillip A.; Ebener, Mark P.; Koonce, Joseph F.; Rutter, Michael A.; Swink, William D.

2003-01-01

Prediction of how host mortality responds to efforts to control sea lampreys (Petromyzon marinus) is central to the integrated management strategy for sea lamprey (IMSL) in the Great Lakes. A parasite-host submodel is used as part of this strategy, and this includes a type-2 multi-species functional response, a developmental response, but no numerical response. General patterns of host species and size selection are consistent with the model assumptions, but some observations appear to diverge. For example, some patterns in sea lamprey marking on hosts suggest increases in selectivity for less preferred hosts and lower host survival when preferred hosts are scarce. Nevertheless, many of the IMSL assumptions may be adequate under conditions targeted by fish community objectives. Of great concern is the possibility that the survival of young parasites (parasitic-phase sea lampreys) varies substantially among lakes or over time. Joint analysis of abundance estimates for parasites being produced in streams and returning spawners could address this. Data on sea lamprey marks is a critical source of information on sea lamprey activity and potential effects. Theory connecting observed marks to sea lamprey feeding activity and host mortality is reviewed. Uncertainties regarding healing and attachment times, the probability of hosts surviving attacks, and problems in consistent classification of marks have led to widely divergent estimates of damages caused by sea lamprey. Laboratory and field studies are recommended to provide a firmer linkage between host blood loss, host mortality, and observed marks on surviving hosts, so as to improve estimates of damage.

Spatiotemporal climatic, hydrological, and environmental variations based on records of annually laminated lake sediments from northern Poland

Science.gov (United States)

Tylmann, W.; Blanke, L.; Kinder, M.; Loewe, T.; Mayr, C.; Ohlendorf, C.; Zolitschka, B.

2009-12-01

In northern Poland there is the unique opportunity to compare varved lake sediment records with distinct climatic trends along a 700 km long W-E transect. Annually laminated Holocene sediment sequences from Lake Lubinskie, Lake Suminko, Lake Lazduny, and Lake Szurpily were cored for high-resolution multiproxy climate and environmental reconstruction in the framework of the Polish-German project “Northern Polish Lake Research” (NORPOLAR). First results from a 139 cm long gravity core of Lake Lazduny (53°51.4’N, 21°57.3’E) document deposition of an organic (mean organic matter: 13.9%; mean biogenic opal: 9.8%) and highly carbonaceous gyttja (mean calcite content: 61.6%). The finely laminated sediment consists of biochemical varves. Pale spring/summer layers composed of autochthonous carbonates alternate with dark fall/winter layers made of organic and minerogenic detritus. The established chronology for the last 1500 calendar-years is based on thin section analysis supported by independent radiometric dating (C-14, Pb-210). Sedimentological, geochemical and stable isotope analyses were carried out with a decadal temporal resolution. Additionally, non-destructive and high-resolution XRF scanning data reveal a rhythmic variation in the Ca content that reflects seasonal calcite deposition. Redox-sensitive elements like Fe, Mn and S are interpreted to be the response to mean winter temperatures: colder winter temperatures → extended lake ice cover → intensification of meromixis → increased Fe/Mn ratio. In turn, these parameters can be linked to NAO (North Atlantic Oscillation) variability, because a negative NAO is related to colder and drier conditions in northeastern Europe. Climate variability is also mirrored by the δ13C record of the endogenic calcite fraction. In mid-latitude lakes calcite precipitation is dominated by productivity-controlled consumption of the dissolved inorganic carbon (DIC) pool. Thus the δ13C record potentially provides a

Online Discovery and Mapping of Great Lakes Climate Change Education and Scientific Research Activities: Building an Online Collaborative Learning Community of Scientists and Educators

Science.gov (United States)

Tuddenham, P.; Bishop, K.; Walters, H.; Carley, S.

2011-12-01

The Great Lakes Climate Change Science and Education Systemic Network (GLCCSESN) project is an NSF-funded CCEP program awarded to Eastern Michigan University in 2010. The College of Exploration is one of the project partners and has conducted a series of online surveys, workshop and focus group to identify a wide range of organizations, individuals, resources and needs related to climate change education and research activities in and about the Great Lakes Region and to provide information about climate change science to the education community. One of the first steps taken to build this community was to build a web site that features a dynamic online map of individuals and organizations concerned about climate change as well as interested in resources and activities specific to the Great Lakes. Individuals and organizations have been, and are still, invited to put themselves on the map at http://greatlakesclimate.org This map of the Great Lakes region provides both a visual representation of activities and resources as well as a database of climate change activities. This map will grow over time as more people and organizations put themselves on the map. The use of online technologies has helped broaden the participation and representation in the GLCCSESN from all states/provinces in the Great Lakes region, encouraging diverse audiences and stakeholders, including scientists, educators, and journalists, etc.to engage with the project. In the fall of 2011 a combined online professional development workshop and focus group is planned. Educators and scientists working on climate change studies and issues related to the Great Lakes will be sharing their work and expertise in an online workshop and focus group. Following the professional development activity a focus group will be conducted online using a model developed as part of a NSF funded COSEE project. The focus group purpose is to review current educational resources and to identify gaps and needs for further

Great Bear Lake, N.W.T. - 1963, No. 13 in 1964 Data Record Series, Canadian Oceanographic Data Center (NODC Accession 7500188)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Great Bear Lake has an area of 29,500 km^2 and it is the fourth largest lake in North America. It is situated at an elevation of 169 m (515 ft) and has a maximum...

Observations of cocooned Hydrobaenus (Diptera: Chironomidae) larvae in Lake Michigan

Science.gov (United States)

Tucker, Taaja R.; Hudson, Patrick L.; Riley, Stephen

2016-01-01

Larvae of the family Chironomidae have developed a variety of ways to tolerate environmental stress, including the formation of cocoons, which allows larvae to avoid unfavorable temperature conditions, drought, or competition with other chironomids. Summer cocoon formation by younger instars of the genus Hydrobaenus Fries allows persistence through increased temperatures and/or intermittent dry periods in arid regions or temporary habitats, but this behavior was not observed in the Great Lakes until the current study. Cocoon-aestivating Hydrobaenus sp. larvae were found in benthic grab samples collected in 2010–2013 near Sleeping Bear Dunes National Lakeshore in northern Lake Michigan with densities up to 7329/m2. The aestivating species was identified as Hydrobaenus johannseni (Sublette, 1967), and the associated chironomid community was typical for an oligotrophic nearshore system. Hydrobaenus cocoon formation in the Great Lakes was likely previously unnoticed due to the discrepancies between the genus' life history and typical benthos sampling procedures which has consequences for describing chironomid communities where Hydrobaenus is present.

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

Science.gov (United States)

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

1994-01-01

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

2010 Great Lakes Restoration Initiative Bathymetric Lidar: Lake Superior

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The data contained in this file contain hydrographic and topographic data collected by the Fugro LADS Mk II system along the Lake Superior coast of Minnessota,...

Great Lakes Hyperspectral Water Quality Instrument Suite for Airborne Monitoring of Algal Blooms

Science.gov (United States)

Lekki, John; Leshkevich, George; Nguyen, Quang-Viet; Flatico, Joseph; Prokop, Norman; Kojima, Jun; Anderson, Robert; Demers, James; Krasowski, Michael

2007-01-01

NASA Glenn Research Center and NOAA Great Lakes Environmental Research Lab are collaborating to utilize an airborne hyperspectral imaging sensor suite to monitor Harmful Algal Blooms (HABs) in the western basin of Lake Erie. The HABs are very dynamic events as they form, spread and then disappear within a 4 to 8 week time period in late summer. They are a concern for human health, fish and wildlife because they can contain blue green toxic algae. Because of this toxicity there is a need for the blooms to be continually monitored. This situation is well suited for aircraft based monitoring because the blooms are a very dynamic event and they can spread over a large area. High resolution satellite data is not suitable by itself because it will not give the temporal resolution due to the infrequent overpasses of the quickly changing blooms. A custom designed hyperspectral imager and a point spectrometer mounted on aT 34 aircraft have been used to obtain data on an algal bloom that formed in the western basin of Lake Erie during September 2006. The sensor suite and operations will be described and preliminary hyperspectral data of this event will be presented

Three air quality studies: Great Lakes ozone formation and nitrogen dry deposition; and Tucson aerosol chemical characterization

Science.gov (United States)

Foley, Theresa

(arsenic, beryllium, cadmium, chromium, cobalt, lead, manganese, and nickel) in the southern Tucson metropolitan area. A Tucson company that uses beryllium oxide to manufacture thermally conductive ceramics has prompted strong citizen concern. This study found that the study area has good air quality with respect to PM10 and metals, with ambient concentrations meeting US Environmental Protection Agency and World Health Organization standards. Beryllium was detected only once (during a dust storm) and was ascribed to naturally-occurring beryllium in the suspended soil. The third paper (to be submitted to the Journal of Great Lakes Research) studies nitrogen dry deposition over Lake Michigan and Lake Superior. Numerous studies have shown that wet and dry deposition of nitrogen has contributed to the eutrophication of coastal waters and declining productivity of marine fisheries. Nitrogen dry deposition over the Great Lakes themselves, as opposed to the shorelines, has not been documented in the peer-reviewed literature. This paper calculates nitrogen dry deposition over Lake Michigan and Lake Superior, using aircraft measurements from the LADCO Aircraft Study, and finds that over-water, nitrogen dry deposition is a significant source of nitrogen to Lake Michigan and Lake Superior.

Rubidium-strontium ages from the Oxford Lake-Knee Lake greenstone belt, northern Manitoba

International Nuclear Information System (INIS)

Clark, G.S.; Cheung, S.-P.

1980-01-01

Rb-Sr whole-rock ages have been determined for rocks from the Oxford Lake-Knee Lake-Gods Lake geenstone belt in the Superior Province of northeastern Manitoba. The age of the Magill Lake Pluton is 2455 +- 35 Ma(lambda 87 Rb = 1.42 x 10 -11 yr -1 ), with an initial 87 Sr/ 86 Sr ratio of 0.7078 +- 0.0043. This granite stock intrudes the Oxford Lake Group, so it is post-tectonic and probably related to the second, weaker stage of metamorphism. The age of the Bayly Lake Pluton is 2424 +- 74 Ma, with an initial 87 Sr/ 86 Sr ratio of 0.7029 +- 0.0001. This granodioritic batholith complex does not intrude the Oxford Lake Group. It is syn-tectonic and metamorphosed. The age of volcanic rocks of the Hayes River Group, from Goose Lake (30 km south of Gods Lake Narrows), is 2680 +- 125 Ma, with an initial 87 Sr/ 86 Sr ratio of 0.7014 +- 0.0009. The age for the Magill Lake and Bayly Lake Plutons can be interpreted as the minimum ages of granite intrusion in the area. The age for the Hayes River Group volcanic rocks is consistent with Rb-Sr ages of volcanic rocks from other Archean greenstone belts within the northwestern Superior Province. (auth)

Citizen science datasets reveal drivers of spatial and temporal variation for anthropogenic litter on Great Lakes beaches.

Science.gov (United States)

Vincent, Anna; Drag, Nate; Lyandres, Olga; Neville, Sarah; Hoellein, Timothy

2017-01-15

Accumulation of anthropogenic litter (AL) on marine beaches and its ecological effects have been a major focus of research. Recent studies suggest AL is also abundant in freshwater environments, but much less research has been conducted in freshwaters relative to oceans. The Adopt-a-BeachTM (AAB) program, administered by the Alliance for the Great Lakes, organizes volunteers to act as citizen scientists by collecting and maintaining data on AL abundance on Great Lakes beaches. Initial assessments of the AAB records quantified sources and abundance of AL on Lake Michigan beaches, and showed that plastic AL was >75% of AL on beaches across all five Great Lakes. However, AAB records have not yet been used to examine patterns of AL density and composition among beaches of all different substrate types (e.g., parks, rocky, sandy), across land-use categories (e.g., rural, suburban, urban), or among seasons (i.e., spring, summer, and fall). We found that most AL on beaches are consumer goods that most likely originate from beach visitors and nearby urban environments, rather than activities such as shipping, fishing, or illegal dumping. We also demonstrated that urban beaches and those with sand rather than rocks had higher AL density relative to other sites. Finally, we found that AL abundance is lowest during the summer, between the US holidays of Memorial Day (last Monday in May) and Labor Day (first Monday in September) at the urban beaches, while other beaches showed no seasonality. This research is a model for utilizing datasets collected by volunteers involved in citizen science programs, and will contribute to AL management by offering priorities for AL types and locations to maximize AL reduction. Copyright © 2016 Elsevier B.V. All rights reserved.

The use of Pb, Sr, and Hg isotopes in Great Lakes precipitation as a tool for pollution source attribution

Energy Technology Data Exchange (ETDEWEB)

Sherman, Laura S., E-mail: lsaylors@umich.edu [University of Michigan, Department of Earth and Environmental Sciences, 1100 N. University Ave., Ann Arbor, MI 48109 (United States); Blum, Joel D. [University of Michigan, Department of Earth and Environmental Sciences, 1100 N. University Ave., Ann Arbor, MI 48109 (United States); Dvonch, J. Timothy [University of Michigan, Air Quality Laboratory, 1415 Washington Heights, Ann Arbor, MI 48109 (United States); Gratz, Lynne E. [University of Washington-Bothell, 18115 Campus Way NE, Bothell, WA 98011 (United States); Landis, Matthew S. [U.S. EPA, Office of Research and Development, Research Triangle Park, NC 27709 (United States)

2015-01-01

The anthropogenic emission and subsequent deposition of heavy metals including mercury (Hg) and lead (Pb) present human health and environmental concerns. Although it is known that local and regional sources of these metals contribute to deposition in the Great Lakes region, it is difficult to trace emissions from point sources to impacted sites. Recent studies suggest that metal isotope ratios may be useful for distinguishing between and tracing source emissions. We measured Pb, strontium (Sr), and Hg isotope ratios in daily precipitation samples that were collected at seven sites across the Great Lakes region between 2003 and 2007. Lead isotope ratios ({sup 207}Pb/{sup 206}Pb = 0.8062 to 0.8554) suggest that Pb deposition was influenced by coal combustion and processing of Mississippi Valley-Type Pb ore deposits. Regional differences in Sr isotope ratios ({sup 87}Sr/{sup 86}Sr = 0.70859 to 0.71155) are likely related to coal fly ash and soil dust. Mercury isotope ratios (δ{sup 202}Hg = − 1.13 to 0.13‰) also varied among the sites, likely due to regional differences in coal isotopic composition, and fractionation occurring within industrial facilities and in the atmosphere. These data represent the first combined characterization of Pb, Sr, and Hg isotope ratios in precipitation collected across the Great Lakes region. We demonstrate the utility of multiple metal isotope ratios in parallel with traditional trace element multivariate statistical modeling to enable more complete pollution source attribution. - Highlights: • We measured Pb, Sr, and Hg isotopes in precipitation from the Great Lakes region. • Pb isotopes suggest that deposition was impacted by coal combustion and metal production. • Sr isotope ratios vary regionally, likely due to soil dust and coal fly ash. • Hg isotopes vary due to fractionation occurring within facilities and the atmosphere. • Isotope results support conclusions of previous trace element receptor modeling.

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

Isotopic Fractionation of Mercury in Great Lakes Precipitation

Science.gov (United States)

Gratz, L. E.; Keeler, G. J.; Blum, J. D.; Sherman, L. S.

2009-12-01

Mercury (Hg) is a hazardous bioaccumulative neurotoxin, and atmospheric deposition is a primary way in which mercury enters terrestrial and aquatic ecosystems. However, the chemical processes and transport regimes that mercury undergoes from emission to deposition are not well understood. Thus the use of mercury isotopes to characterize the biogeochemical cycling of mercury is a rapidly growing area of study. Precipitation samples were collected in Chicago, IL, Holland, MI, and Dexter, MI from April 2007 - October 2007 to begin examining the isotopic fractionation of atmospheric mercury in the Great Lakes region. Results show that mass-dependent fractionation relative to NIST-3133 (MDF - δ202Hg) ranged from -0.8‰ to 0.2‰ (±0.2‰) in precipitation samples, while mass-independent fractionation (MIF - Δ199Hg) varied from 0.1‰ to 0.6‰ (±0.1‰). Although clear urban-rural differences were not observed, this may be due to the weekly collection of precipitation samples rather than collection of individual events, making it difficult to truly characterize the meteorology and source influences associated with each sample and suggesting that event-based collection is necessary during future sampling campaigns. Additionally, total vapor phase mercury samples were collected in Dexter, MI in 2009 to examine isotopic fractionation of mercury in ambient air. In ambient samples δ202Hg ranged from 0.3‰ to 0.5‰ (±0.1‰), however Δ199Hg was not significant. Because mercury in precipitation is predominantly Hg2+, while ambient vapor phase mercury is primarily Hg0, these results may suggest the occurrence of MIF during the oxidation of Hg0 to Hg2+ prior to deposition. Furthermore, although it has not been previously reported or predicted, MIF of 200Hg was also detected. Δ200Hg ranged from 0.0‰ to 0.2‰ in precipitation and from -0.1‰ to 0.0‰ in ambient samples. This work resulted in methodological developments in the collection and processing of

Mercury distribution in the main compartments of the eutrophic Lake Candia (Northern Italy

Directory of Open Access Journals (Sweden)

Gian Maria BEONE

2009-08-01

Full Text Available Total mercury (T-Hg and organic mercury (mainly methylmercury, MeHg concentrations in the most important compartments (water, sediment, macrophytes, zooplankton, mussels and fish of the shallow and eutrophic Lake Candia (Turin, Northern Italy were measured. The decreasing sequence of the T-Hg concentrations is as follows: cat-fish (143 μg kg-1 d.w., zooplankton (77 μg kg-1 d.w., Unio pictorum mancus (37.9 μg kg-1 d.w., macrophytes (28.9 μg kg-1 d.w.. The content of mercury in mussel tissues increased with the size of the animal, but the relationship between Hg concentration and tissue weight was negative, indicating that the rate of mercury accumulation was lower than the tissue growth rate. The amount of mercury accumulated in the mussels living in the lake sediments was estimated to be 0.54 μg m-2. The importance of mercury biomagnification is also discussed.

Evaluation of herbacceous biomass crops in the northern Great Plains. Final report

Energy Technology Data Exchange (ETDEWEB)

Meyer, D.W.; Norby, W.E.; Erickson, D.O.; Johnson, R.G. [North Dakota State Univ., Fargo, ND (United States)

1994-08-01

Herbaceous lignocellulose crops are a potential renewable feedstock for biochemical conversion systems second in size to wood products. Several herbaceous crops are utilized as forage crops in the northern Great Plains, but forage quality considerations usually dictates a early harvest. Biomass cropping does not have this constraint; therefore, little information was available on herbaceous crops utilized as energy crops prior to this project. Our primary objectives were to evaluate the biomass yield and select chemical components of several herbaceous crops for energy crops in the northern Great Plains, compare the economic feasibility of energy crops with common competing crops, and evaluate biomass cropping on summer fallow lands. Three good, two marginal, and one irrigated sites were used during 1988 to 1992 for the first component. At least six perennial and four annual biomass species were included at all sites. Three to four nitrogen (N) levels and a crop-recrop comparison (annuals only) were management intensities included. Biomass cropping on idled lands was performed on dryland at Carrington and evaluated the effects of removing leguminous biomass on fallowed lands. This report summarizes results from the 5-year project.

The food of the lake trout (Cristivomer namaycush namaycush) and of the lawyer (Lota maculosa) of Lake Michigan

Science.gov (United States)

Van Oosten, John; Deason, Hilary J.

1938-01-01

This paper reports on a qualitative and quantitative analysis of the contents of 4,979 lake trout stomachs (593 examined in 1930 and 1,253 collected in 1931 from southern Lake Michigan, 1,446 from northern Lake Michigan and 1,687 from Green Bay in 1932), and of a total of 1,528 lawyer stomachs (172 examined in 1930 and 734 collected in 1931 from southern Lake Michigan, 612 from northern Lake Michigan and 10 from Green Bay in 1932). The food of the trout consisted of 98 per cent by volume of fish of which Cottidae and Coregonidae were the principal constituents. Cottidae were dominant in southern Lake Michigan (72 per cent by volume), Coregonidae in northern Lake Michigan (51 per cent) but the lake shiner, Notropis atherinides, was most important in Green Bay in the spring of the year (64 per cent). The lawyer food consisted of 74 per cent by volume of fish and 26 per cent invertebrates. Dominant items were Cottidae (76 per cent by volume) in southern Lake Michigan, Coregonidae (51 per cent) and Pontoporeia (37 per cent) in northern Lake Michigan, and Percopsis (34 per cent) and Mysis (26 per cent) in Green Bay. Data are also presented on the frequency of occurrence (number of stomachs) of the food items and its variation with the sizes of the trout and lawyers, depths of water, seasons, and localities; on the number of individual fish of each species destroyed by the trout and lawyers; and on the calculated volume of the food fishes preceding digestion. The lake trout and lawyer are competitors for the same food, are both predators of the commercially important Coregonidae, and the lawyer through its consumption of invertebrates is a food competitor of the Coregonidae.

A comparison of water quality criteria for the Great Lakes based on human and wildlife health

Science.gov (United States)

Ludwig, James P.; Giesy, John P.; Summer, Cheryl L.; Bowerman, William; Aulerich, Richard J.; Bursian, Steven J.; Auman, Heidi J.; Jones, Paul D.; Williams, Lisa L.; Tillitt, Donald E.; Gilbertson, Michael

1993-01-01

Water quality criteria (WQC) can be derived in several ways. The usual techniques involve hazard and risk assessment procedures. For non-persistent, non-biomagnified compounds and elements, WQC are experimentally derived from their acute and chronic toxicity to aquatic organisms. For those persistent chlorinated hydrocarbons (PCHs) that are bioaccumulated and biomagnified, these traditional techniques have not been effective, partly because effects higher in the food web were not considered. Polychlorinated biphenyls (PCBs) are the bioaccumulative synthetic chemicals of primary toxicological significance to the Great Lakes biota which have caused widespread injury to wildlife. In the Laurentian Great Lakes, the primary emphasis of hazard assessments has been on the potential for adverse effects in humans who eat fish. The primary regulatory endpoint of traditional hazard and risk assessments underlying current WQC are the probabilities of additional cancers occurring in the human population. The analysis presented here indicates that this is not adequate to restore sensitive wildlife species that are highly exposed to PCBs, especially those that have suffered serious population declines. Because WQC are legal instruments, the methods of deriving WQC have large implications for remediation, litigation, and damage assessments. Here WQC are derived for six species based on the responses of wildlife in the field or produced by feeding fish to surrogate species, rather than projecting a potential of increased cancer rates in humans. If the most sensitive wildlife species are restored and protected for very sensitive reproductive endpoints, then all components of the ecosystem, including human health, should be more adequately protected. The management of Great Lakes wildlife requires an understanding of the injury and causal relationships to persistent toxic substances.

Contaminants of emerging concern in tributaries to the Laurentian Great Lakes: II. Biological consequences of exposure

Science.gov (United States)

Thomas, Linnea M.; Jorgenson, Zachary G.; Brigham, Mark E.; Choy, Steven J.; Moore, Jeremy N.; Banda, Jo A.; Gefell, D.J.; Minarik, Thomas A.; Schoenfuss, Heiko L.

2017-01-01

The Laurentian Great Lakes contain one fifth of the world’s surface freshwater and have been impacted by human activity since the Industrial Revolution. In addition to legacy contaminants, nitrification and invasive species, this aquatic ecosystem is also the recipient of Contaminants of Emerging Concern (CECs) with poorly understood biological consequences. In the current study, we documented the presence, concentrations, and biological effects of CECs across 27 field sites in six Great Lakes tributaries by examining over 2250 resident and caged sunfish (Lepomis ssp.) for a variety of morphological and physiological endpoints and related these results to CEC occurrence. CEC were ubiquitous across studies sites and their presence and concentrations in water and sediment were highest in effluent dominated rivers and downstream of municipal wastewater treatment plant discharges. However, even putative upstream reference sites were not free of CEC presence and fish at these sites exhibited biological effects consistent with CEC exposure. Only the Fox River exhibited consistent adverse biological effects, including increased relative liver size, greater prominence of hepatocyte vacuoles and increased plasma glucose concentrations. Canonical Redundancy Analysis revealed consistent patterns of biological consequences of CEC exposure across all six tributaries. Increasing plasma glucose concentrations, likely as a result of pollutant-induced metabolic stress, were associated with increased relative liver size and greater prominence of hepatocyte vacuoles. These indicators of pollutant exposure were inversely correlated with indicators of reproductive potential including smaller gonad size and less mature gametes. The current study highlights the need for greater integration of chemical and biological studies and suggests that CECs in the Laurentian Great Lakes Basin may adversely affect the reproductive potential of exposed fish populations.

Novel effects-based monitoring approaches to evaluate chemicals of emerging concern in Great Lakes areas of concern

Science.gov (United States)

As part of an on-going program of research in support of the Great Lakes Restoration Initiative, we have been developing effects-based biomonitoring tools to evaluate the occurrence and potential hazards associated with Chemicals of Emerging Concern (CECs). Over three field seaso...

Trace element exposure of whooper swans (Cygnus cygnus) wintering in a marine lagoon (Swan Lake), northern China.

Science.gov (United States)

Wang, Feng; Xu, Shaochun; Zhou, Yi; Wang, Pengmei; Zhang, Xiaomei

2017-06-30

Trace element poisoning remains a great threat to various waterfowl and waterbirds throughout the world. In this study, we determined the trace element exposure of herbivorous whooper swans (Cygnus cygnus) wintering in Swan Lake (Rongcheng), an important swan protection area in northern China. A total of 70 samples including abiotic factors (seawater, sediments), food sources (seagrass, macroalgae), feathers and feces of whooper swans were collected from the marine lagoon during the winters of 2014/2015 and 2015/2016. Concentrations of Cu, Zn, Pb, Cr, Cd, Hg and As were determined to investigate the trace element exposure of whooper swans wintering in the area. Results showed that there was an increasing trend in sediment trace element concentrations, compared with historical data. The trace element concentrations in swan feces most closely resembled those of Zostera marina leaves, especially for Cd and Cr. The Zn and Hg concentrations in the swan feces (49.57 and 0.01mg/kg, respectively) were lower than the minimum values reported in the literature for other waterfowls, waterbirds and terrestrial birds. However, the concentrations of the other five trace elements fell within the lower and mediate range of values reported for birds across the world. These results suggest that the whooper swans wintering in Swan Lake, Rongcheng are not suffering severe trace element exposure; however, with the increasing input of trace elements to the lagoon, severe adverse impacts may occur in the future, and we therefore suggest that the input of trace elements to this area should be curbed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of regional climate simulations over the Great Lakes region driven by three global data sets

Science.gov (United States)

Shiyuan Zhong; Xiuping Li; Xindi Bian; Warren E. Heilman; L. Ruby Leung; William I. Jr. Gustafson

2012-01-01

The performance of regional climate simulations is evaluated for the Great Lakes region. Three 10-year (1990-1999) current-climate simulations are performed using the MM5 regional climate model (RCM) with 36-km horizontal resolution. The simulations employed identical configuration and physical parameterizations, but different lateral boundary conditions and sea-...

Thermal processes of thermokarst lakes in the continuous permafrost zone of northern Siberia - observations and modeling (Lena River Delta, Siberia)

Science.gov (United States)

Boike, J.; Georgi, C.; Kirilin, G.; Muster, S.; Abramova, K.; Fedorova, I.; Chetverova, A.; Grigoriev, M.; Bornemann, N.; Langer, M.

2015-10-01

Thermokarst lakes are typical features of the northern permafrost ecosystems, and play an important role in the thermal exchange between atmosphere and subsurface. The objective of this study is to describe the main thermal processes of the lakes and to quantify the heat exchange with the underlying sediments. The thermal regimes of five lakes located within the continuous permafrost zone of northern Siberia (Lena River Delta) were investigated using hourly water temperature and water level records covering a 3-year period (2009-2012), together with bathymetric survey data. The lakes included thermokarst lakes located on Holocene river terraces that may be connected to Lena River water during spring flooding, and a thermokarst lake located on deposits of the Pleistocene Ice Complex. Lakes were covered by ice up to 2 m thick that persisted for more than 7 months of the year, from October until about mid-June. Lake-bottom temperatures increased at the start of the ice-covered period due to upward-directed heat flux from the underlying thawed sediment. Prior to ice break-up, solar radiation effectively warmed the water beneath the ice cover and induced convective mixing. Ice break-up started at the beginning of June and lasted until the middle or end of June. Mixing occurred within the entire water column from the start of ice break-up and continued during the ice-free periods, as confirmed by the Wedderburn numbers, a quantitative measure of the balance between wind mixing and stratification that is important for describing the biogeochemical cycles of lakes. The lake thermal regime was modeled numerically using the FLake model. The model demonstrated good agreement with observations with regard to the mean lake temperature, with a good reproduction of the summer stratification during the ice-free period, but poor agreement during the ice-covered period. Modeled sensitivity to lake depth demonstrated that lakes in this climatic zone with mean depths > 5 m develop

Hydraulic and water-quality data collection for the investigation of Great Lakes tributaries for Asian carp spawning and egg-transport suitability

Science.gov (United States)

Murphy, Elizabeth A.; Jackson, P. Ryan

2013-01-01

If the invasive Asian carps (bighead carp Hypophthalmichthys nobilis and silver carp Hypophthalmichthys molitrix) migrate to the Great Lakes, in spite of the efforts to stop their advancement, these species will require the fast-flowing water of the Great Lakes tributaries for spawning and recruitment in order to establish a growing population. Two Lake Michigan tributaries (the Milwaukee and St. Joseph Rivers) and two Lake Erie tributaries (the Maumee and Sandusky Rivers) were investigated to determine if these tributaries possess the hydraulic and water-quality characteristics to allow successful spawning of Asian carps. To examine this issue, standard U.S. Geological Survey sampling protocols and instrumentation for discharge and water-quality measurements were used, together with differential global positioning system data for georeferencing. Non-standard data-processing techniques, combined with detailed laboratory analysis of Asian carp egg characteristics, allowed an assessment of the transport capabilities of each of these four tributaries. This assessment is based solely on analysis of observed data and did not utilize the collected data for detailed transport modeling.

Particulate matter concentrations for mono-slope beef cattle facilities in the Northern Great Plains

Science.gov (United States)

Confined cattle facilities are an increasingly common housing system in the Northern Great Plains region of the United States. Producers may maintain a deep-bedded manure pack (Pack), they may remove all bedding/manure material from the pens weekly (Scrape), or use a combination of management styles...

The Proliferation and Illicit Trafficking of Small Arms and Light Weapons in the Great Lakes and Horn of Africa

National Research Council Canada - National Science Library

Kiugu, Aphaxard M

2007-01-01

In Africa, the effect of the proliferation of small arms and light weapons (SALW) continues to impact negatively on socioeconomic development, particularly within the Great Lakes and Horn of Africa...

Feasibility study of a Great Lakes bioenergy system.

Science.gov (United States)

Hacatoglu, Kevork; McLellan, P James; Layzell, David B

2011-01-01

A bioenergy production and delivery system built around the Great Lakes St. Lawrence Seaway (GLSLS) transportation corridor was assessed for its ability to mitigate energy security and climate change risks. The land area within 100 km of the GLSLS and associated railway lines was estimated to be capable of producing at least 30 Mt(dry) yr(-1) of lignocellulosic biomass with minimal adverse impacts on food and fibre production. This was estimated to be sufficient to displace all of the coal-fired electricity in Ontario plus more than 620 million L of green diesel (equivalent to 5.3% of diesel consumption in GLSLS provinces). Lifecycle greenhouse gas emissions were 88% and 76% lower than coal-fired power and conventional diesel, respectively. Production costs of $120 MWh(-1) for power and up to $30 GJ(-1) ($1.1 L(-1)) for green diesel were higher than current market prices, but a value for low-carbon energy would narrow the price differential. Copyright © 2010 Elsevier Ltd. All rights reserved.

Observation of thermal plumes from submerged discharges in the Great Lakes and their implications for modeling and monitoring

International Nuclear Information System (INIS)

Ditmars, J.D.; Paddock, R.A.; Frigo, A.A.

1977-01-01

Measurements of thermal plumes from submerged discharges of power plant cooling waters into the Great Lakes provide the opportunity to view the mixing processes at prototype scales and to observe the effects of the ambient environment on those processes. Examples of thermal plume behavior in Great Lakes' ambient environments are presented to demonstrate the importance of measurements of the detailed structure of the ambient environment, as well as of the plumes, for interpretation of prototype data for modeling and monitoring purposes. The examples are drawn from studies by Argonne National Laboratory (ANL) at the Zion Nuclear PowerStation and the D. C. Cook Nuclear Plant on Lake Michigan and at the J. A. FitzPatrick Nuclear Power Plant on Lake Ontario. These studies included measurements of water temperatures from a moving boat which provide a quasi-synoptic view of the three-dimensional temperature structure of the thermal plume and ambient water environment. Additional measurements of water velocities, which are made with continuously recording, moored, and profiling current meters, and of wind provide data on the detailed structure of the ambient environment. The detailed structure of the ambient environment, in terms of current, current shear, variable winds, and temperature stratification, often influence greatly thermal plume behavior. Although predictive model techniques and monitoring objectives often ignore the detailed aspects of the ambient environment, useful interpretation of prototype data for model evaluation or calibration and monitoring purposes requires detailed measurement of the ambient environment. Examination of prototype thermal plume data indicates that, in several instances, attention to only the gross characteristics of the ambient environment can be misleading and could result in significant errors in model calibration and extrapolation of data bases gathered in monitoring observations

Prevalence of toxin-producing Clostridium botulinum associated with the macroalga Cladophora in three Great Lakes: growth and management

Science.gov (United States)

Chun, Chan Lan; Kahn, Chase I.; Borchert, Andrew J.; Byappanahalli, Muruleedhara N.; Whitman, Richard L.; Peller, Julie R.; Pier, Christina; Lin, Guangyun; Johnson, Eric A.; Sadowsky, Michael J.

2015-01-01

The reemergence of avian botulism caused by Clostridium botulinum type E has been observed across the Great Lakes in recent years. Evidence suggests an association between the nuisance algae, Cladophoraspp., and C. botulinum in nearshore areas of the Great Lakes. However, the nature of the association between Cladophora and C. botulinum is not fully understood due, in part, to the complex food web interactions in this disease etiology. In this study, we extensively evaluated their association by quantitatively examining population size and serotypes of C. botulinum in algal mats collected from wide geographic areas in lakes Michigan, Ontario, and Erie in 2011–2012 and comparing them with frequencies in other matrices such as sand and water. A high prevalence (96%) of C. botulinum type E was observed inCladophora mats collected from shorelines of the Great Lakes in 2012. Among the algae samples containing detectable C. botulinum, the population size of C. Botulinum type E was 100–104 MPN/g dried algae, which was much greater (up to 103 fold) than that found in sand or the water column, indicating thatCladophora mats are sources of this pathogen. Mouse toxinantitoxin bioassays confirmed that the putativeC. botulinum belonged to the type E serotype. Steam treatment was effective in reducing or eliminating C. botulinum type E viable cells in Cladophora mats, thereby breaking the potential transmission route of toxin up to the food chain. Consequently, our data suggest that steam treatment incorporated with a beach cleaning machine may be an effective treatment of Cladophora-borne C. botulinum and may reduce bird mortality and human health risks.

Active intra-basin faulting in the Northern Basin of Lake Malawi from seismic reflection data

Science.gov (United States)

Shillington, D. J.; Chindandali, P. R. N.; Scholz, C. A.; Ebinger, C. J.; Onyango, E. A.; Peterson, K.; Gaherty, J. B.; Nyblade, A.; Accardo, N. J.; McCartney, T.; Oliva, S. J.; Kamihanda, G.; Ferdinand, R.; Salima, J.; Mruma, A. H.

2016-12-01

Many questions remain about the development and evolution of fault systems in weakly extended rifts, including the relative roles of border faults and intra-basin faults, and segmentation at various scales. The northern Lake Malawi (Nyasa) rift in the East African Rift System is an early stage rift exhibiting pronounced tectonic segmentation, which is defined by 100-km-long border faults. The basins also contain a series of intrabasinal faults and associated synrift sediments. The occurrence of the 2009 Karonga Earthquake Sequence on one of these intrabasinal faults indicates that some of them are active. Here we present new multichannel seismic reflection data from the Northern Basin of the Malawi Rift collected in 2015 as a part of the SEGMeNT (Study of Extension and maGmatism in Malawi aNd Tanzania) project. This rift basin is bound on its east side by the west-dipping Livingstone border fault. Over 650 km of seismic reflection profiles were acquired in the Northern Basin using a 500 to 1540 cu in air gun array and a 1200- to 1500-m seismic streamer. Dip lines image a series of north-south oriented west-dipping intra-basin faults and basement reflections up to 5 s twtt near the border fault. Cumulative offsets on intra-basin faults decrease to the west. The largest intra-basin fault has a vertical displacement of >2 s two-way travel time, indicating that it has accommodated significant total extension. Some of these intra-basin faults offset the lake bottom and the youngest sediments by up to 50 s twtt ( 37 m), demonstrating they are still active. The two largest intra-basin faults exhibit the largest offsets of young sediments and also correspond to the area of highest seismicity based on analysis of seismic data from the 89-station SEGMeNT onshore/offshore network (see Peterson et al, this session). Fault patterns in MCS profiles vary along the basin, suggesting a smaller scale of segmentation of faults within the basin; these variations in fault patterns

77 FR 73646 - Essar Steel Minnesota, LLC v. Great Lakes Gas Transmission Limited Partnership; Notice of Complaint

Science.gov (United States)

2012-12-11

... Transmission Limited Partnership (Respondent), alleging that the Respondent has failed to comply with the... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. RP13-313-000] Essar Steel Minnesota, LLC v. Great Lakes Gas Transmission Limited Partnership; Notice of Complaint Take notice that on...

HYPERSPECTRAL REMOTE SENSING, GPS, AND GIS APPLICATIONS IN OPPORTUNISTIC PLANT SPECIES MONITORING OF GREAT LAKES COASTAL WETLANDS

Science.gov (United States)

Coastal wetlands of the Laurentian Great Lakes (LGL) are among the most fragmented and disturbed ecosystems of the world, with a long history of human-induced disturbance. LGL wetlands have undergone losses in the biological diversity that coincides with an increase in the presen...

The community structure and seasonal dynamics of plankton in Bange Lake, northern Tibet, China

Science.gov (United States)

Zhao, Wen; Zhao, Yuanyi; Wang, Qiaohan; Zheng, Mianping; Wei, Jie; Wang, Shan

2016-11-01

The seasonal variations in biomass, abundance, and species composition of plankton in relation to hydrography were studied in the saline Bange Lake, northern Tibet, China. Sampling was carried out between one to three times per month from May 2001 to July 2002. Salinity ranged from 14 to 146. The air and water temperature exhibited a clear seasonal pattern, and mean annual temperatures were approximately 4.8°C and 7.3°C, respectively. The lowest water temperature occurred in winter from December to March at -2°C and the highest in June and July at 17.7°C. Forty-one phytoplankton taxa, 21 zooplankton, and 5 benthic or facultative zooplankton were identified. The predominant phytoplankton species were Gloeothece linearis, Oscillatoria tenuis, Gloeocapsa punctata, Ctenocladus circinnatus, Dunaliella salina, and Spirulina major. The predominant zooplankton species included Holophrya actra, Brachionus plicatilis, Daphniopsis tibetana, Cletocamptus dertersi, and Arctodiaptomus salinus. The mean annual total phytoplankton density and biomass for the entire lake were 4.52×107 cells/L and 1.60 mg/L, respectively. The annual mean zooplankton abundance was 52, 162, 322, and 57, 144 ind./L, in the three sublakes. The annual mean total zooplankton biomass in Lakes 1-3 was 1.23, 9.98, and 2.13 mg/L, respectively. The annual mean tychoplankton abundances in Bg1, 2, and 3 were 47, 67, and 654 ind./L. The annual mean tychoplankton biomass was 2.36, 0.16, and 2.03 mg/L, respectively. The zooplankton biomass (including tychoplankton) in the lake was 9.11 mg/L. The total number of plankton species in the salt lake was significantly negatively correlated with salinity.

Big Ship Data: Using vessel measurements to improve estimates of temperature and wind speed on the Great Lakes

Science.gov (United States)

Fries, Kevin; Kerkez, Branko

2017-05-01

The sheer size of many water systems challenges the ability of in situ sensor networks to resolve spatiotemporal variability of hydrologic processes. New sources of vastly distributed and mobile measurements are, however, emerging to potentially fill these observational gaps. This paper poses the question: How can nontraditional measurements, such as those made by volunteer ship captains, be used to improve hydrometeorological estimates across large surface water systems? We answer this question through the analysis of one of the largest such data sets: an unprecedented collection of one million unique measurements made by ships on the North American Great Lakes from 2006 to 2014. We introduce a flexible probabilistic framework, which can be used to integrate ship measurements, or other sets of irregular point measurements, into contiguous data sets. The performance of this framework is validated through the development of a new ship-based spatial data product of water temperature, air temperature, and wind speed across the Great Lakes. An analysis of the final data product suggests that the availability of measurements across the Great Lakes will continue to play a large role in the confidence with which these large surface water systems can be studied and modeled. We discuss how this general and flexible approach can be applied to similar data sets, and how it will be of use to those seeking to merge large collections of measurements with other sources of data, such as physical models or remotely sensed products.

Coastal Cover Change Analysis Program (C-CAP) Great Lakes 2001-era land cover change analysis (NODC Accession 0038694)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data is the 2001 era or late-date classification of the Great Lakes. This data set consists of about 74 partial Landsat 7 Thematic Mapper scenes which were...

Dewatering of planned Key Lake open pits in northern Saskatchewan

International Nuclear Information System (INIS)

Unland, W.; Holl, N.

1980-01-01

The engineering design and experience gained so far with a dewatering system for an open-pit uranium mine planned at Key Lake in Northern Saskatchewan are presented. An extensive unconfined overburden aquifer is hydraulically connected with the underlying Athabasca Formation and basement rocks, both of relatively low hydraulic conductivity. The overburden aquifer is embedded in a bedrock trough, with the deepest depression between the planned pits. Hydrogeological data were used in a numerical dewatering model simulating groundwater flow at different stages of the pit development. Based on the model results, the enginering design had to provide for different pumping rates, varying between 1.0 and 0.21 m 3 /sec. This problem was solved by using a double line pressure system. The design concept for the complete peripheral discharge system and the well design used for 26 dewatering wells are discussed. (auth)

Economic feasibility of sail power devices on Great Lakes bulk carriers

Energy Technology Data Exchange (ETDEWEB)

1982-03-24

Progress is reported in a project to determine whether retro-fitting existing Great Lakes bulk carriers with auxiliary sail powering devices is economically feasible. The approach being used is to apply known technology both in terms of sail devices and calculation methods to determine the amount of fuel that can be saved and the probable cost of the sail device. Progress includes the identification and collection of data needed to determine the state of the art as well as to model the problem. Several sail powering devices were compared and an unstayed cat rig was chosen for further analysis and its performance characteristics were incorporated into a computer model, which is flow charted. (LEW)

Halogenated flame retardants in the Great Lakes environment.

Science.gov (United States)

Venier, Marta; Salamova, Amina; Hites, Ronald A

2015-07-21

Flame retardants are widely used industrial chemicals that are added to polymers, such as polyurethane foam, to prevent them from rapidly burning if exposed to a small flame or a smoldering cigarette. Flame retardants, especially brominated flame retardants, are added to many polymeric products at percent levels and are present in most upholstered furniture and mattresses. Most of these chemicals are so-called "additive" flame retardants and are not chemically bound to the polymer; thus, they migrate from the polymeric materials into the environment and into people. As a result, some of these chemicals have become widespread pollutants, which is a concern given their possible adverse health effects. Perhaps because of their environmental ubiquity, the most heavily used group of brominated flame retardants, the polybrominated diphenyl ethers (PBDEs), was withdrawn from production and use during the 2004-2013 period. This led to an increasing demand for other flame retardants, including other brominated aromatics and organophosphate esters. Although little is known about the use or production volumes of these newer flame retardants, it is evident that some of these chemicals are also becoming pervasive in the environment and in humans. In this Account, we describe our research on the occurrence of halogenated and organophosphate flame retardants in the environment, with a specific focus on the Great Lakes region. This Account starts with a short introduction to the first generation of brominated flame retardants, the polybrominated biphenyls, and then presents our measurements of their replacement, the PBDEs. We summarize our data on PBDE levels in babies, bald eagles, and in air. Once these compounds came off the market, we began to measure several of the newer flame retardants in air collected on the shores of the Great Lakes once every 12 days. These new measurements focus on a tetrabrominated benzoate, a tetrabrominated phthalate, a hexabrominated diphenoxyethane

Land use patterns, ecoregion, and microcystin relationships in U.S. lakes and reservoirs: a preliminary evaluation

Science.gov (United States)

Beaver, John R.; Manis, Erin E.; Loftin, Keith A.; Graham, Jennifer L.; Pollard, Amina I.; Mitchell, Richard M.

2014-01-01

A statistically significant association was found between the concentration of total microcystin, a common class of cyanotoxins, in surface waters of lakes and reservoirs in the continental U.S. with watershed land use using data from 1156 water bodies sampled between May and October 2007 as part of the USEPA National Lakes Assessment. Nearly two thirds (65.8%) of the samples with microcystin concentrations ≥1.0 μg/L (n = 126) were limited to three nutrient and water quality-based ecoregions (Corn Belt and Northern Great Plains, Mostly Glaciated Dairy Region, South Central Cultivated Great Plains) in watersheds with strong agricultural influence. canonical correlation analysis (CCA) indicated that both microcystin concentrations and cyanobacteria abundance were positively correlated with total nitrogen, dissolved organic carbon, and temperature; correlations with total phosphorus and water clarity were not as strong. This study supports a number of regional lake studies that suggest that land use practices are related to cyanobacteria abundance, and extends the potential impacts of agricultural land use in watersheds to include the production of cyanotoxins in lakes.

Impacts of CO/sub 2/-induced climatic change on water resources in the Great Lakes Basin

Energy Technology Data Exchange (ETDEWEB)

Cohen, S J

1986-01-01

Scenarios of CO/sub 2/-induced climatic change, based on models produced by the Goddard Institute for Space Studies (GISS) and the Geophysical Fluid Dynamics Lab (GFDL), were used to estimate future changes in water supply in the Great Lakes Basin. The major components of annual Net Basin Supply, surface runoff and lake evaporation, were estimated using the Thornthwaite water balance model and the mass transfer approach, respectively. Two scenarios were derived from each climatic change model, one based on present normal winds, the other assuming reduced wind speeds. A third scenario was derived from GFDL, using wind speeds generated by the GFDL model. Results varied from a decrease in Net Basin Supply of 28.9% for GISS-normal winds, to a decrease of 11.7% for GFDL-reduced wind speeds. All five scenarios projected decreases. These differences in projection will have to be considered when performing climate impact studies, since economic activities affected by lake levels would probably experience different impacts under these scenarios.

Quantifying uncertainties of seismic Bayesian inversion of Northern Great Plains

Science.gov (United States)

Gao, C.; Lekic, V.

2017-12-01

Elastic waves excited by earthquakes are the fundamental observations of the seismological studies. Seismologists measure information such as travel time, amplitude, and polarization to infer the properties of earthquake source, seismic wave propagation, and subsurface structure. Across numerous applications, seismic imaging has been able to take advantage of complimentary seismic observables to constrain profiles and lateral variations of Earth's elastic properties. Moreover, seismic imaging plays a unique role in multidisciplinary studies of geoscience by providing direct constraints on the unreachable interior of the Earth. Accurate quantification of uncertainties of inferences made from seismic observations is of paramount importance for interpreting seismic images and testing geological hypotheses. However, such quantification remains challenging and subjective due to the non-linearity and non-uniqueness of geophysical inverse problem. In this project, we apply a reverse jump Markov chain Monte Carlo (rjMcMC) algorithm for a transdimensional Bayesian inversion of continental lithosphere structure. Such inversion allows us to quantify the uncertainties of inversion results by inverting for an ensemble solution. It also yields an adaptive parameterization that enables simultaneous inversion of different elastic properties without imposing strong prior information on the relationship between them. We present retrieved profiles of shear velocity (Vs) and radial anisotropy in Northern Great Plains using measurements from USArray stations. We use both seismic surface wave dispersion and receiver function data due to their complementary constraints of lithosphere structure. Furthermore, we analyze the uncertainties of both individual and joint inversion of those two data types to quantify the benefit of doing joint inversion. As an application, we infer the variation of Moho depths and crustal layering across the northern Great Plains.

Grasshopper responses to fire and postfire grazing in the northern Great Plains vary among species

Science.gov (United States)

Rangeland management practices such as burning and grazing management may affect grasshopper populations by impacting development, survival and reproduction. Experiments are lacking in the northern Great Plains examining the effects of fire and grazing intensity on grasshoppers. As part of a larger ...

Utilization of GIS modeling in geoenvironmental studies of Qaroun Lake, El Fayoum Depression, Egypt

Science.gov (United States)

Attia, Abdelaal H.; El-Sayed, Salah Abdelwahab; El-Sabagh, Moustafa E.

2018-02-01

Qaroun Lake, the study area, is a natural protectorate located at the northern part of El Fayoum Depression, Egypt. An integrated approach including hydrochemistry, mineralogy of sediments and GIS analysis and modeling was conducted in order to determine the different geoenvironmental parameters affecting the lake environmental system. Forty two environmental water and sediment samples were collected from the lake and relevant drains in 2013. The water samples were analyzed for major ions and trace elements and the sediment ones were analyzed for clay and non-clay minerals. This study showed that the saline water of the lake (31490 Mg2+ > Ca2+ > K+ - Cl- > SO42- > HCO3- > CO32-. The water salt assemblages were KCl - NaCl - Na2SO4 - MgSO4 - CaSO4 - Ca(HCO3)2 reflecting a mixed water type. The contents of NaCl, Na2SO4 and MgSO4 salts were found to be fully controlled with the lake depths. The hydrogeochemical investigations revealed that the evaporation concentration is the primary process of the lake water evolution. The presence of trace elements in the lake water is essentially of allochtonous origin. The GIS-based maps indicated that the concentrations of Zn, Co, Mo, Pb, F and Cd elements in water had increased in the eastern part of the lake; meanwhile, the contents of NO3- ions had increased in the southwestern part indicating that these parts were the most vulnerable to the potential pollution with such elements. The XRD analysis revealed the existence of different mineral assemblages (quartz, kaolinite, goethite, calcite, halite, hematite, feldspar, gypsum, dolomite and saponite) in bottom sediments. The mineral concentrations varied greatly from place to another place along the lake and their distributions were asymmetric. The dominant minerals were the quartz and calcite. The mineralogical compositions of sediments were highly affected by the natural and man-mad activities. The most effective processes were the type of the water and solid materials coming

Using medically-derived iodine-131 to track sewage effluent in the Laurentian Great Lakes.

Science.gov (United States)

Montenero, Michael P; Dilbone, Elizabeth K; Waples, James T

2017-10-15

Tracking sewage wastewater in a large lake is difficult. Concentrations of pharmaceuticals that can be used as indicator compounds are quickly diluted and not easy to measure. In this study, we examined the potential of using medically-derived iodine-131 ( 131 I, t ½  = 8.02 d) as a tracer for Milwaukee sewage effluent in Lake Michigan. 131 I activities in sewage effluent from two Milwaukee wastewater treatment plants (WWTPs) were measured in conjunction with 131 I activities in water, sediment and biota in the Milwaukee Outer Harbor and Lake Michigan. 131 I discharge rates from both WWTPS ranged from 34 ± 15 to 1807 ± 24 MBq d -1 , with average and median 131 I discharges of 278 and 129 MBq d -1 . A budget of 131 I in the Milwaukee Outer Harbor - based on measured sediment and water column inventories - showed that ∼11% of the 131 I discharged to the harbor was scavenged to bottom sediments, ∼19% decayed in the harbor water column, and ∼70% was flushed out of the harbor to Lake Michigan. From this budget, we derived a harbor flushing rate of 3.1 days. In Lake Michigan, 131 I activity was found in Cladophora algae (undetected to 91 ± 2 Bq kg -1 ) along ∼40 km of shoreline. Benthic trawl samples showed 131 I activity up to 8 km from shore. Calculated 131 I length scales were 30 km alongshore and 3.4 km offshore and corresponded to sewage effluent dispersion rates of ∼2.6 km d -1 and ∼0.3 km d -1 in along- and offshore directions. Using 131 I as a tracer of sewage effluent from other coastal municipalities to the Laurentian Great Lakes appears feasible, particularly for larger (>10 5 ) population centers. Copyright © 2017 Elsevier Ltd. All rights reserved.

Using Land Surface Phenology to Detect Land Use Change in the Northern Great Plains

Science.gov (United States)

Nguyen, L. H.; Henebry, G. M.

2017-12-01

The Northern Great Plains of the US have been undergoing many types of land cover / land use change over the past two decades, including expansion of irrigation, conversion of grassland to cropland, biofuels production, urbanization, and fossil fuel mining. Much of the literature on these changes has relied on post-classification change detection based on a limited number of observations per year. Here we demonstrate an approach to characterize land dynamics through land surface phenology (LSP) by synergistic use of image time series at two scales. Our study areas include regions of interest (ROIs) across the Northern Great Plains located within Landsat path overlap zones to boost the number of valid observations (free of clouds or snow) each year. We first compute accumulated growing degree-days (AGDD) from MODIS 8-day composites of land surface temperature (MOD11A2 and MYD11A2). Using Landsat Collection 1 surface reflectance-derived vegetation indices (NDVI, EVI), we then fit at each pixel a downward convex quadratic model linking the vegetation index to each year's progression of AGDD. This quadratic equation exhibits linearity in a mathematical sense; thus, the fitted models can be linearly mixed and unmixed using a set of LSP endmembers (defined by the fitted parameter coefficients of the quadratic model) that represent "pure" land cover types with distinct seasonal patterns found within the region, such as winter wheat, spring wheat, maize, soybean, sunflower, hay/pasture/grassland, developed/built-up, among others. Information about land cover corresponding to each endmember are provided by the NLCD (National Land Cover Dataset) and CDL (Cropland Data Layer). We use linear unmixing to estimate the likely proportion of each LSP endmember within particular areas stratified by latitude. By tracking the proportions over the 2001-2011 period, we can quantify various types of land transitions in the Northern Great Plains.

Large Lakes Dominate CO2 Evasion From Lakes in an Arctic Catchment

Science.gov (United States)

Rocher-Ros, Gerard; Giesler, Reiner; Lundin, Erik; Salimi, Shokoufeh; Jonsson, Anders; Karlsson, Jan

2017-12-01

CO2 evasion from freshwater lakes is an important component of the carbon cycle. However, the relative contribution from different lake sizes may vary, since several parameters underlying CO2 flux are size dependent. Here we estimated the annual lake CO2 evasion from a catchment in northern Sweden encompassing about 30,000 differently sized lakes. We show that areal CO2 fluxes decreased rapidly with lake size, but this was counteracted by the greater overall coverage of larger lakes. As a result, total efflux increased with lake size and the single largest lake in the catchment dominated the CO2 evasion (53% of all CO2 evaded). By contrast, the contribution from the smallest ponds (about 27,000) was minor (evasion at the landscape scale.

A lake-centric geospatial database to guide research and inform management decisions in an Arctic watershed in northern Alaska experiencing climate and land-use changes

Science.gov (United States)

Jones, Benjamin M.; Arp, Christopher D.; Whitman, Matthew S.; Nigro, Debora A.; Nitze, Ingmar; Beaver, John; Gadeke, Anne; Zuck, Callie; Liljedahl, Anna K.; Daanen, Ronald; Torvinen, Eric; Fritz, Stacey; Grosse, Guido

2017-01-01

Lakes are dominant and diverse landscape features in the Arctic, but conventional land cover classification schemes typically map them as a single uniform class. Here, we present a detailed lake-centric geospatial database for an Arctic watershed in northern Alaska. We developed a GIS dataset consisting of 4362 lakes that provides information on lake morphometry, hydrologic connectivity, surface area dynamics, surrounding terrestrial ecotypes, and other important conditions describing Arctic lakes. Analyzing the geospatial database relative to fish and bird survey data shows relations to lake depth and hydrologic connectivity, which are being used to guide research and aid in the management of aquatic resources in the National Petroleum Reserve in Alaska. Further development of similar geospatial databases is needed to better understand and plan for the impacts of ongoing climate and land-use changes occurring across lake-rich landscapes in the Arctic.

An Integrated Approach To Offshore Wind Energy Assessment: Great Lakes 3D Wind Experiment

Energy Technology Data Exchange (ETDEWEB)

Barthelmie, R. J. [Cornell Univ., Ithaca, NY (United States). Sibley School of Mechanical & Aerospace Engineering; Pryor, S. C. [Cornell Univ., Ithaca, NY (United States). Dept. of Earth and Atmospheric Sciences

2017-09-18

This grant supported fundamental research into the characterization of flow parameters of relevance to the wind energy industry focused on offshore and the coastal zone. A major focus of the project was application of the latest generation of remote sensing instrumentation and also integration of measurements and numerical modeling to optimize characterization of time-evolving atmospheric flow parameters in 3-D. Our research developed a new data-constrained Wind Atlas for the Great Lakes, and developed new insights into flow parameters in heterogeneous environments. Four experiments were conducted during the project: At a large operating onshore wind farm in May 2012; At the National Renewable Energy Laboratory National Wind Technology Center (NREL NWTC) during February 2013; At the shoreline of Lake Erie in May 2013; and At the Wind Energy Institute of Canada on Prince Edward Island in May 2015. The experiment we conducted in the coastal zone of Lake Erie indicated very complex flow fields and the frequent presence of upward momentum fluxes and resulting distortion of the wind speed profile at turbine relevant heights due to swells in the Great Lakes. Additionally, our data (and modeling) indicate the frequent presence of low level jets at 600 m height over the Lake and occasions when the wind speed profile across the rotor plane may be impacted by this phenomenon. Experimental data and modeling of the fourth experiment on Prince Edward Island showed that at 10-14 m escarpment adjacent to long-overseas fetch the zone of wind speed decrease before the terrain feature and the increase at (and slightly downwind of) the escarpment is ~3–5% at turbine hub-heights. Additionally, our measurements were used to improve methods to compute the uncertainty in lidar-derived flow properties and to optimize lidar-scanning strategies. For example, on the basis of the experimental data we collected plus those from one of our research partners we advanced a new methodology to

Expansion rate and geometry of floating vegetation mats on the margins of thermokarst lakes, northern Seward Peninsula, Alaska, USA

Science.gov (United States)

Parsekian, A.D.; Jones, Benjamin M.; Jones, M.; Grosse, G.; Walter, Anthony K.M.; Slater, L.

2011-01-01

Investigations on the northern Seward Peninsula in Alaska identified zones of recent (<50years) permafrost collapse that led to the formation of floating vegetation mats along thermokarst lake margins. The occurrence of floating vegetation mat features indicates rapid degradation of near-surface permafrost and lake expansion. This paper reports on the recent expansion of these collapse features and their geometry is determined using geophysical and remote sensing measurements. The vegetation mats were observed to have an average thickness of 0.57m and petrophysical modeling indicated that gas content of 1.5-5% enabled floatation above the lake surface. Furthermore, geophysical investigation provides evidence that the mats form by thaw and subsidence of the underlying permafrost rather than terrestrialization. The temperature of the water below a vegetation mat was observed to remain above freezing late in the winter. Analysis of satellite and aerial imagery indicates that these features have expanded at maximum rates of 1-2myr-1 over a 56year period. Including the spatial coverage of floating 'thermokarst mats' increases estimates of lake area by as much as 4% in some lakes. ?? 2011 John Wiley & Sons, Ltd.

Expansion rate and geometry of floating vegetation mats on the margins of thermokarst lakes, northern Seward Peninsula, Alaska, USA

Science.gov (United States)

Parsekian, A.D.; Jones, Benjamin M.; Jones, M.; Grosse, G.; Walter, Anthony K.M.; Slater, L.

2011-01-01

Investigations on the northern Seward Peninsula in Alaska identified zones of recent (geometry is determined using geophysical and remote sensing measurements. The vegetation mats were observed to have an average thickness of 0.57m and petrophysical modeling indicated that gas content of 1.5-5% enabled floatation above the lake surface. Furthermore, geophysical investigation provides evidence that the mats form by thaw and subsidence of the underlying permafrost rather than terrestrialization. The temperature of the water below a vegetation mat was observed to remain above freezing late in the winter. Analysis of satellite and aerial imagery indicates that these features have expanded at maximum rates of 1-2myr-1 over a 56year period. Including the spatial coverage of floating 'thermokarst mats' increases estimates of lake area by as much as 4% in some lakes. ?? 2011 John Wiley & Sons, Ltd.

Recreation conflict of riparian landowners with personal watercraft and motorboat use along the New York's Great Lakes

Science.gov (United States)

Cheng-Ping Wang; Chad P. Dawson

2002-01-01

Riparian landowners of the New York's Great Lakes (NYGL) are reportedly in conflict with some motorboat and personal watercraft (PWC) use. Goal interference theory was used to explain landowners' perceived conflict caused by motorboat and PWC use. A study conducted in the NYGL area surveyed the riparian landowners' perceived conflict and problems caused...

Use of Fish Telemetry in Rehabilitation Planning, Management, and Monitoring in Areas of Concern in the Laurentian Great Lakes

Science.gov (United States)

Brooks, J. L.; Boston, C.; Doka, S.; Gorsky, D.; Gustavson, K.; Hondorp, D.; Isermann, D.; Midwood, J. D.; Pratt, T. C.; Rous, A. M.; Withers, J. L.; Krueger, C. C.; Cooke, S. J.

2017-12-01

Freshwater ecosystems provide many ecosystem services; however, they are often degraded as a result of human activity. To address ecosystem degradation in the Laurentian Great Lakes, Canada and the United States of America established the Great Lakes Water Quality Agreement (GLWQA). In 1987, 43 highly polluted and impacted areas were identified under the GLWQA as having one or more of 14 Beneficial Use Impairments (BUIs) to the physical and chemical habitat for fish, wildlife and humans, and were designated as Areas of Concern (AOC). Subnational jurisdictions combined with local stakeholders, with support from federal governments, developed plans to remediate and restore these sites. Biotelemetry (the tracking of animals using electronic tags) provides information on the spatial ecology of fish in the wild relevant to habitat management and stock assessment. Here, seven case studies are presented where biotelemetry data were directly incorporated within the AOC Remedial Action Plan (RAP) process. Specific applications include determining seasonal fish-habitat associations to inform habitat restoration plans, identifying the distribution of pollutant-indicator species to identify exposure risk to contamination sources, informing the development of fish passage facilities to enable fish to access fragmented upstream habitats, and assessing fish use of created or restored habitats. With growing capacity for fish biotelemetry research in the Great Lakes, we discuss the strengths and weaknesses of incorporating biotelemetry into AOC RAP processes to improve the science and practice of restoration and to facilitate the delisting of AOCs.

Use of fish telemetry in rehabilitation planning, management, and monitoring in Areas of Concern in the Laurentian Great Lakes

Science.gov (United States)

Brooks, J.L.; Boston, C.; Doka, Susan E.; Gorsky, Dimitry; Gustavson, K.; Hondorp, Darryl W.; Isermann, Daniel A.; Midwood, Jonathan D.; Pratt, T.C.; Rous, Andrew M.; Withers, J. L.; Krueger, C.C.; Cooke, S.J.

2017-01-01

Freshwater ecosystems provide many ecosystem services; however, they are often degraded as a result of human activity. To address ecosystem degradation in the Laurentian Great Lakes, Canada and the United States of America established the Great Lakes Water Quality Agreement (GLWQA). In 1987, 43 highly polluted and impacted areas were identified under the GLWQA as having one or more of 14 Beneficial Use Impairments (BUIs) to the physical and chemical habitat for fish, wildlife and humans, and were designated as Areas of Concern (AOC). Subnational jurisdictions combined with local stakeholders, with support from federal governments, developed plans to remediate and restore these sites. Biotelemetry (the tracking of animals using electronic tags) provides information on the spatial ecology of fish in the wild relevant to habitat management and stock assessment. Here, seven case studies are presented where biotelemetry data were directly incorporated within the AOC Remedial Action Plan (RAP) process. Specific applications include determining seasonal fish–habitat associations to inform habitat restoration plans, identifying the distribution of pollutant-indicator species to identify exposure risk to contamination sources, informing the development of fish passage facilities to enable fish to access fragmented upstream habitats, and assessing fish use of created or restored habitats. With growing capacity for fish biotelemetry research in the Great Lakes, we discuss the strengths and weaknesses of incorporating biotelemetry into AOC RAP processes to improve the science and practice of restoration and to facilitate the delisting of AOCs.

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

Science.gov (United States)

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

1999-03-01

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

AN ECOLOGICAL REVIEW OF CLADOPHORA GLOMERATA (CHLOROPHYTA) IN THE LAURENTIAN GREAT LAKES(1).

Science.gov (United States)

Higgins, Scott N; Malkin, Sairah Y; Todd Howell, E; Guildford, Stephanie J; Campbell, Linda; Hiriart-Baer, Veronique; Hecky, Robert E

2008-08-01

Cladophora glomerata (L.) Kütz. is, potentially, the most widely distributed macroalga throughout the world's freshwater ecosystems. C. glomerata has been described throughout North America, Europe, the Atlantic Islands, the Caribbean Islands, Asia, Africa, Australia and New Zealand, and the Pacific Islands. Cladophora blooms were a common feature of the lower North American Great Lakes (Erie, Michigan, Ontario) from the 1950s through the early 1980s and were largely eradicated through the implementation of a multibillion-dollar phosphorus (P) abatement program. The return of widespread blooms in these lakes since the mid-1990s, however, was not associated with increases in P loading. Instead, current evidence indicates that the resurgence in blooms was directly related to ecosystem level changes in substratum availability, water clarity, and P recycling associated with the establishment of dense colonies of invasive dreissenid mussels. These results support the hypothesis that dreissenid mussel invasions may induce dramatic shifts in energy and nutrient flow from pelagic zones to the benthic zone. © 2008 Phycological Society of America.

Pesticide presence in Great Lakes tributaries and comparison to ToxCast and other water quality benchmarks to screen for potential biological effects

Science.gov (United States)

Product Description:Pesticides are a broad category of current use chemicals that pose potential threats to aquatic organisms in and around the Great Lakes basin. In this study, we monitored for over 200 pesticides or their break down products in 16 major tributaries to the Great...

Status and trends of the Lake Huron deepwater demersal fish ommunity, 2008

Science.gov (United States)

Roseman, Edward F.; O'Brien, Timothy P.; Riley, Stephen C.; Farha, Steve A.; French, John R.

2009-01-01

The U.S.Geological Survey Great Lakes Science Center has conducted trawl surveys to assess annual changes in the deepwater demersal fish community of Lake Huron since 1973. Since 1992, surveys have been carried out using a 21 m wing trawl towed on-contour at depths ranging from 9 to 110 m on fixed transects. Sample sites include five ports in U.S. waters with less frequent sampling near Goderich, Ontario. The 2008 fall bottom trawl survey was carried out between October 24 and November 20, 2008 and sampled only the three northern U.S. ports at DeTour, Hammond Bay, and Alpena due to mechanical problems with the research vessel and prolonged periods of bad weather. Therefore, all data presented for 2008 are based on samples collected from these ports. Compared to previous years, alewife populations in Lake Huron remain at low levels after collapsing in 2004. Age-0 alewife density and biomass appears to have increased slightly but overall levels remain near the nadir observed in 2004. Density and biomass of adult and juvenile rainbow smelt showed a decrease from 2007 despite record-high abundance of juveniles observed in 2005, suggesting recruitment was low. Numbers of adult and juvenile bloater were low despite recent high year-classes. Abundances for most other prey species were similar to the low levels observed in 2005 - 2007. We captured one wild juvenile lake trout in 2008 representing the fifth consecutive year that wild lake trout were captured in the survey. Based on pairwise graphical comparisons and nonparametric correlation analyses, dynamics of prey abundance at the three northern ports followed lakewide trends since 1992. Density of benthic macroinvertebrates was at an all-time low in 2008 since sampling began in 2001. The decline in abundance was due to decreases in all taxonomic groups and a large reduction in recruitment of quagga mussels. Density of Diporeia at northern ports in 2008 was the lowest observed. Diporeia were found only at 73-m sites of

Changes in the Global Hydrological Cycle: Lessons from Modeling Lake Levels at the Last Glacial Maximum

Science.gov (United States)

Lowry, D. P.; Morrill, C.

2011-12-01

Geologic evidence shows that lake levels in currently arid regions were higher and lakes in currently wet regions were lower during the Last Glacial Maximum (LGM). Current hypotheses used to explain these lake level changes include the thermodynamic hypothesis, in which decreased tropospheric water vapor coupled with patterns of convergence and divergence caused dry areas to become more wet and vice versa, the dynamic hypothesis, in which shifts in the jet stream and Inter-Tropical Convergence Zone (ITCZ) altered precipitation patterns, and the evaporation hypothesis, in which lake expansions are attributed to reduced evaporation in a colder climate. This modeling study uses the output of four climate models participating in phase 2 of the Paleoclimate Modeling Intercomparison Project (PMIP2) as input into a lake energy-balance model, in order to test the accuracy of the models and understand the causes of lake level changes. We model five lakes which include the Great Basin lakes, USA; Lake Petén Itzá, Guatemala; Lake Caçó, northern Brazil; Lake Tauca (Titicaca), Bolivia and Peru; and Lake Cari-Laufquen, Argentina. These lakes create a transect through the drylands of North America through the tropics and to the drylands of South America. The models accurately recreate LGM conditions in 14 out of 20 simulations, with the Great Basin lakes being the most robust and Lake Caçó being the least robust, due to model biases in portraying the ITCZ over South America. An analysis of the atmospheric moisture budget from one of the climate models shows that thermodynamic processes contribute most significantly to precipitation changes over the Great Basin, while dynamic processes are most significant for the other lakes. Lake Cari-Laufquen shows a lake expansion that is most likely attributed to reduced evaporation rather than changes in regional precipitation, suggesting that lake levels alone may not be the best indicator of how much precipitation this region

Decay model for biocide treatment of unballasted vessels: application for the Laurentian Great Lakes.

Science.gov (United States)

Sano, Larissa L; Bartell, Steven M; Landrum, Peter F

2005-10-01

A biocide decay model was developed to assess the potential efficacy and environmental impacts associated with using glutaraldehyde to treat unballasted overseas vessels trading on the Laurentian Great Lakes. The results of Monte Carlo simulations indicate that effective glutaraldehyde concentrations can be maintained for the duration of a vessel's oceanic transit (approximately 9-12 days): During this transit, glutaraldehyde concentrations were predicted to decrease by approximately 10% from initial treatment levels (e.g., 500 mgL(-1)). In terms of environmental impacts, mean glutaraldehyde concentrations released at Duluth-Superior Harbor, MN were predicted to be 100-fold lower than initial treatment concentrations, and ranged from 3.2 mgL(-1) (2 SD: 2.74) in April to 0.7 mgL(-1) (2 SD: 1.28) in August. Sensitivity analyses indicated that the re-ballasting dilution factor was the major variable governing final glutaraldehyde concentrations; however, lake surface temperatures became increasingly important during the warmer summer months.

Aerosol Emissions from Great Lakes Harmful Algal Blooms

Energy Technology Data Exchange (ETDEWEB)

May, Nathaniel W. [Department; Olson, Nicole E. [Department; Panas, Mark [Department; Axson, Jessica L. [Department; Tirella, Peter S. [Department; Kirpes, Rachel M. [Department; Craig, Rebecca L. [Department; Gunsch, Matthew J. [Department; China, Swarup [William; Laskin, Alexander [William; Ault, Andrew P. [Department; Department; Pratt, Kerri A. [Department; Department

2017-12-20

In freshwater lakes, harmful algal blooms (HABs) of Cyanobacteria (blue-green algae) produce toxins that impact human health. However, little is known about the chemical species present in lake spray aerosol (LSA) produced from wave-breaking in freshwater HABs. In this study, a laboratory LSA generator produced aerosols from freshwater samples collected from Lake Michigan and Lake Erie during HAB and non-bloom conditions. Particles were analyzed for size and chemical composition by single particle mass spectrometry, electron microscopy, and fluorescence microscopy, with three distinct types of LSA identified with varying levels of organic carbon and biological material associated with calcium salts. LSA autofluorescence increases with blue-green algae concentration, showing that organic molecules of biological origin are incorporated in LSA from HABs. The number fraction of LSA with biological mass spectral markers also increases with particle diameter (greater than 0.5 μm), showing that HABs have size-dependent impacts on aerosol composition. The highest number fraction of LSA enriched in organic carbon were observed in particles less than 0.5 μm in diameter. Understanding the transfer of organic and biogenic material from freshwater to the atmosphere via LSA particles is crucial for determining health and climate effects due to HABs.

Tides and lake-level variations in the great Patagonian lakes: Observations, modelling and geophysical implications.

Science.gov (United States)

Marderwald, Eric; Richter, Andreas; Horwath, Martin; Hormaechea, Jose Luis; Groh, Andreas

2016-04-01

In Patagonia, the glacial-isostatic adjustment (GIA) to past ice-mass changes (Ivins & James 2004; Klemann et al. 2007) is of particular interest in the context of the determination of the complex regional rheology related to plate subduction in a triple-junction constellation. To further complicate the situation, GIA is overlaid with load deformation not only due to present ice mass changes but also due to water-level changes in the lakes surrounding the icefields and the ocean surrounding Patagonia. These elastic deformations affect the determination of glacial-isostatic uplift rates from GPS observations (Dietrich et al. 2010; Lange et al. 2014). Observations of lake tides and their comparison with the theoretical tidal signal have been used previously to validate predictions of ocean tidal loading and have revealed regional deviations from conventional global elastic earth models (Richter et al. 2009). In this work we investigate the tides and lake-level variations in Lago Argentino, Lago Viedma, Lago San Martín/O'Higgins and Lago Buenos Aires/General Carrera. This allows us to test, among other things, the validity of tidal loading models. We present pressure tide-gauge records from two sites in Lago Argentino extending over 2.5 years (Richter et al. 2015). These observations are complemented by lake-level records provided by the Argentine National Hydrometeorological Network. Based on these lake-level time series the principal processes affecting the lake level are identified and quantified. Lake-level changes reflecting variations in lake volume are dominated by a seasonal cycle exceeding 1 m in amplitude. Lake-volume changes occur in addition with a daily period in response to melt water influx from surrounding glaciers. In Lago Argentino sporadic lake-volume jumps are caused by bursting of the ice dam of Perito Moreno glacier. Water movements in these lakes are dominated by surface seiches reaching 20 cm in amplitude. A harmonic tidal analysis of the lake

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

Science.gov (United States)

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

2016-01-01

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

Great Lakes water quality initiative technical support document for human health criteria and values (January 1993 draft)

International Nuclear Information System (INIS)

1993-01-01

The goal of the human health criteria and values for the Great Lakes is the protection of humans from unacceptable exposure to toxicants from consumption of contaminated fish, drinking water and water related to recreational activities. Emphasis is on the protection of the individual in evaluating toxicity information and its application in the derivation of criteria and values

The use of Pb, Sr, and Hg isotopes in Great Lakes precipitation as a tool for pollution source attribution

Science.gov (United States)

The anthropogenic emission and subsequent deposition of heavy metals including mercury (Hg) and lead (Pb) presents human health and environmental concerns. Although it is known that local and regional sources of these metals contribute to deposition in the Great Lakes region, it ...

The first US National Coastal Condition Assessment survey in the Great Lakes: Development of the GIS frame and exploration of spatial variation in nearshore water quality results

Science.gov (United States)

A comprehensive approach to assess conditions in the Great Lakes nearshore zone has been lacking for decades. We had the opportunity to conduct a pilot survey in Lake Erie (45 sites) in summer 2009 and to develop a full survey across the 5 lakes (~400 sites) as part of the US N...

The Key Lake project

International Nuclear Information System (INIS)

1991-01-01

Key Lake is located in the Athabasca sand stone basin, 640 kilometers north of Saskatoon, Saskatchewan, Canada. The three sources of ore at Key Lake contain 70 100 tonnes of uranium. Features of the Key Lake Project were described under the key headings: work force, mining, mill process, tailings storage, permanent camp, environmental features, worker health and safety, and economic benefits. Appendices covering the historical background, construction projects, comparisons of western world mines, mining statistics, Northern Saskatchewan surface lease, and Key Lake development and regulatory agencies were included

Coastal Change Analysis Program (C-CAP) Great Lakes; Michigan 1996-2001 era land cover change analysis (NODC Accession 0042189)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set is a change analysis of 1996-era C-CAP land cover and 2001-era C-CAP land cover for the State of Michigan, in the Great Lakes Region of the U.S. This...

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

Science.gov (United States)

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

2017-12-01

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

Bacterial pathogen gene abundance and relation to recreational water quality at seven Great Lakes beaches.

Science.gov (United States)

Oster, Ryan J; Wijesinghe, Rasanthi U; Haack, Sheridan K; Fogarty, Lisa R; Tucker, Taaja R; Riley, Stephen C

2014-12-16

Quantitative assessment of bacterial pathogens, their geographic variability, and distribution in various matrices at Great Lakes beaches are limited. Quantitative PCR (qPCR) was used to test for genes from E. coli O157:H7 (eaeO157), shiga-toxin producing E. coli (stx2), Campylobacter jejuni (mapA), Shigella spp. (ipaH), and a Salmonella enterica-specific (SE) DNA sequence at seven Great Lakes beaches, in algae, water, and sediment. Overall, detection frequencies were mapA>stx2>ipaH>SE>eaeO157. Results were highly variable among beaches and matrices; some correlations with environmental conditions were observed for mapA, stx2, and ipaH detections. Beach seasonal mean mapA abundance in water was correlated with beach seasonal mean log10 E. coli concentration. At one beach, stx2 gene abundance was positively correlated with concurrent daily E. coli concentrations. Concentration distributions for stx2, ipaH, and mapA within algae, sediment, and water were statistically different (Non-Detect and Data Analysis in R). Assuming 10, 50, or 100% of gene copies represented viable and presumably infective cells, a quantitative microbial risk assessment tool developed by Michigan State University indicated a moderate probability of illness for Campylobacter jejuni at the study beaches, especially where recreational water quality criteria were exceeded. Pathogen gene quantification may be useful for beach water quality management.

Impacts of Climate Change on Soil Erosion in the Great Lakes Region

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Lili Wang

2018-06-01

Full Text Available Quantifying changes in potential soil erosion under projections of changing climate is important for the sustainable management of land resources, as soil loss estimates will be helpful in identifying areas susceptible to erosion, targeting future erosion control efforts, and/or conservation funding. Therefore, the macro-scale Variable Infiltration Capacity—Water Erosion Prediction Project (VIC-WEPP soil erosion model was utilized to quantify soil losses under three climate change scenarios (A2, A1B, B1 using projections from three general circulation models (GFDL, PCM, HadCM3 for the Great Lakes region from 2000 to 2100. Soil loss was predicted to decrease throughout three future periods (2030s, 2060s, and 2090s by 0.4–0.7 ton ha−1 year−1 (4.99–23.2% relative to the historical period (2000s with predicted air temperature increases of 0.68–4.34 °C and precipitation increases of 1.74–63.7 mm year−1 (0.23–8.6%. In the forested northern study domain erosion kept increasing by 0.01–0.18 ton ha−1 year−1 over three future periods due to increased precipitation of 9.7–68.3 mm year−1. The southern study domain covered by cropland and grassland had predicted soil loss decreases of 0.01–1.43 ton ha−1 year−1 due to air temperature increases of 1.75–4.79 °C and reduced precipitation in the summer. Fall and winter had greater risks of increased soil loss based on predictions for these two seasons under the A2 scenario, with the greatest cropland soil loss increase due to increased fall precipitation, and combined effects of increases in both precipitation and air temperature in the winter. Fall was identified with higher risks under the A1B scenario, while spring and summer were identified with the greatest risk of increased soil losses under the B1 scenario due to the increases in both precipitation and air temperature.

Great Lakes/Saint Lawrence Seaway Regional Transportation Study for U.S. Army Corps of Engineers. Phase II. Summary Report.

Science.gov (United States)

1982-03-01

center in Hamilton and the public utilities in Toronto. The vast majority of these shipments are loaded at U.S. Lake Erie ports. (2) The Great Lakes...fish spawning, including egg survival, behavior, distribution of species and spawning, nursery and food/cover habitats in wetlands. Although fish...30P 305 CHICAGO 0 IR 21 41 74 43 141 16P 16P CALUMFT HR 0 7S9 3%0 %On IOA4 631 1934 240A 2414 INDIANA HA 0 1 4 7 10 13 1r is BURNS HOP 0 115 65 , A ?07

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

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

2013-07-01

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

Using Scenario Development to Encourage Tourism Business Resilience in the Great Lakes